atmel_serial: Atmel RS485 support v2
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From: Ryan Mallon on 29 Mar 2010 15:50 Claudio Scordino wrote: > Hi all, > > this is the new version of the patch to add RS485 support to the > atmel_serial driver. It's been changed according to Ryan Mallon's > comments. > > This new patch has been tested again (with and without DMA) by Sebastian > Heutling (CC:-ed). A few more, mostly nitpicky, comments below. > Many thanks to all, > > Claudio > > > atmel_serial: Atmel RS485 support > > Signed-off-by: Claudio Scordino <claudio(a)evidence.eu.com> > Signed-off-by: Michael Trimarchi <michael(a)evidence.eu.com> > Signed-off-by: Rick Bronson <rick(a)efn.org> > Signed-off-by: Sebastian Heutling <Sebastian.Heutling(a)who-ing.de> > --- > arch/arm/include/asm/ioctls.h | 2 + > arch/arm/mach-at91/include/mach/board.h | 2 + > drivers/serial/atmel_serial.c | 244 ++++++++++++++++++++++++++----- > 3 files changed, 212 insertions(+), 36 deletions(-) > > diff --git a/arch/arm/include/asm/ioctls.h b/arch/arm/include/asm/ioctls.h > index a91d8a1..82f2177 100644 > --- a/arch/arm/include/asm/ioctls.h > +++ b/arch/arm/include/asm/ioctls.h > @@ -70,6 +70,8 @@ > #define TIOCGICOUNT 0x545D /* read serial port inline interrupt counts */ > #define FIOQSIZE 0x545E > > +#define TIOCSRS485 0x5461 > + > /* Used for packet mode */ > #define TIOCPKT_DATA 0 > #define TIOCPKT_FLUSHREAD 1 > diff --git a/arch/arm/mach-at91/include/mach/board.h b/arch/arm/mach-at91/include/mach/board.h > index ceaec6c..fd8a385 100644 > --- a/arch/arm/mach-at91/include/mach/board.h > +++ b/arch/arm/mach-at91/include/mach/board.h > @@ -39,6 +39,7 @@ > #include <linux/usb/atmel_usba_udc.h> > #include <linux/atmel-mci.h> > #include <sound/atmel-ac97c.h> > +#include <linux/serial.h> > > /* USB Device */ > struct at91_udc_data { > @@ -146,6 +147,7 @@ struct atmel_uart_data { > short use_dma_tx; /* use transmit DMA? */ > short use_dma_rx; /* use receive DMA? */ > void __iomem *regs; /* virtual base address, if any */ > + struct serial_rs485 rs485; /* rs485 settings */ > }; Can you re-indent this structure so the rest of the members line up with the new rs485 one. > extern void __init at91_add_device_serial(void); > > diff --git a/drivers/serial/atmel_serial.c b/drivers/serial/atmel_serial.c > index 2c9bf9b..826a885 100644 > --- a/drivers/serial/atmel_serial.c > +++ b/drivers/serial/atmel_serial.c > @@ -38,6 +38,7 @@ > #include <linux/dma-mapping.h> > #include <linux/atmel_pdc.h> > #include <linux/atmel_serial.h> > +#include <linux/uaccess.h> > > #include <asm/io.h> > > @@ -59,6 +60,9 @@ > > #include <linux/serial_core.h> > > +static void atmel_start_rx(struct uart_port *port); > +static void atmel_stop_rx(struct uart_port *port); > + > #ifdef CONFIG_SERIAL_ATMEL_TTYAT > > /* Use device name ttyAT, major 204 and minor 154-169. This is necessary if we > @@ -93,6 +97,7 @@ > #define UART_GET_BRGR(port) __raw_readl((port)->membase + ATMEL_US_BRGR) > #define UART_PUT_BRGR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_BRGR) > #define UART_PUT_RTOR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_RTOR) > +#define UART_PUT_TTGR(port, v) __raw_writel(v, (port)->membase + ATMEL_US_TTGR) > > /* PDC registers */ > #define UART_PUT_PTCR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_PTCR) > @@ -147,6 +152,10 @@ struct atmel_uart_port { > unsigned int irq_status_prev; > > struct circ_buf rx_ring; > + > + struct serial_rs485 rs485; /* rs485 settings */ > + > + unsigned int tx_done_mask; > }; Do we need all the whitespace here? > static struct atmel_uart_port atmel_ports[ATMEL_MAX_UART]; > @@ -187,6 +196,81 @@ static bool atmel_use_dma_tx(struct uart_port *port) > } > #endif > > +/* Enable or disable the rs485 support */ > +void atmel_config_rs485(struct uart_port *port, struct serial_rs485 *rs485conf) > +{ > + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); > + unsigned long flags; > + unsigned int mode; > + > + spin_lock_irqsave(&port->lock, flags); > + > + mode = UART_GET_MR(port); > + > + /* Resetting serial mode to RS232 (0x0) */ > + mode &= ~ATMEL_US_USMODE; > + > + atmel_port->rs485 = *rs485conf; > + > + if (rs485conf->flags & SER_RS485_ENABLED) { > + dev_dbg(port->dev, "Setting UART to RS485\n"); > + atmel_port->tx_done_mask = ATMEL_US_TXEMPTY; > + UART_PUT_TTGR(port, rs485conf->delay_rts_before_send); > + mode |= ATMEL_US_USMODE_RS485; > + } else { > + dev_dbg(port->dev, "Setting UART to RS232\n"); > + if (atmel_use_dma_tx(port)) > + atmel_port->tx_done_mask = ATMEL_US_ENDTX | \ > + ATMEL_US_TXBUFE; You only need to use backslashes on split lines in macro definitions. > + else > + atmel_port->tx_done_mask = ATMEL_US_TXRDY; > + } > + UART_PUT_MR(port, mode); > + > + spin_unlock_irqrestore(&port->lock, flags); > +} > + > + > +static ssize_t show_rs485(struct device *dev, struct device_attribute *attr, \ > + char *buf) > +{ Same here, and a couple more places. > + struct platform_device *pdev = to_platform_device(dev); > + struct uart_port *port = platform_get_drvdata(pdev); > + unsigned int current_mode; > + > + current_mode = UART_GET_MR(port) & ATMEL_US_USMODE; > + return snprintf(buf, PAGE_SIZE, "%u\n", current_mode); > +} > + > +static ssize_t set_rs485(struct device *dev, struct device_attribute *attr, \ > + const char *buf, size_t len) > +{ > + struct platform_device *pdev = to_platform_device(dev); > + struct uart_port *port = platform_get_drvdata(pdev); > + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); > + struct serial_rs485 rs485conf = atmel_port->rs485; > + unsigned int value; > + > + if (!buf) > + return -EINVAL; > + > + value = !!(simple_strtoul(buf, NULL, 0)); > + > + if (value) { > + rs485conf.flags |= SER_RS485_ENABLED; > + /* 0x4 is the normal reset value. */ > + rs485conf.delay_rts_before_send = 0x00000004; > + } else { > + rs485conf.flags &= ~(SER_RS485_ENABLED); Don't need the parenthesis here. > + } > + > + atmel_config_rs485(port, &rs485conf); > + > + return strnlen(buf, PAGE_SIZE); > +} > + > +static DEVICE_ATTR(rs485, 0644, show_rs485, set_rs485); > + > /* > * Return TIOCSER_TEMT when transmitter FIFO and Shift register is empty. > */ > @@ -202,6 +286,7 @@ static void atmel_set_mctrl(struct uart_port *port, u_int mctrl) > { > unsigned int control = 0; > unsigned int mode; > + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); > > #ifdef CONFIG_ARCH_AT91RM9200 > if (cpu_is_at91rm9200()) { > @@ -236,6 +321,17 @@ static void atmel_set_mctrl(struct uart_port *port, u_int mctrl) > mode |= ATMEL_US_CHMODE_LOC_LOOP; > else > mode |= ATMEL_US_CHMODE_NORMAL; > + > + /* Resetting serial mode to RS232 (0x0) */ > + mode &= ~ATMEL_US_USMODE; > + > + if (atmel_port->rs485.flags & SER_RS485_ENABLED) { > + dev_dbg(port->dev, "Keeping UART to RS485\n"); "Setting" UART to RS485 probably makes more sense here (and couple of other places). > + UART_PUT_TTGR(port, atmel_port->rs485.delay_rts_before_send); > + mode |= ATMEL_US_USMODE_RS485; > + } else { > + dev_dbg(port->dev, "Keeping UART to RS232\n"); > + } > UART_PUT_MR(port, mode); > } > > @@ -268,12 +364,17 @@ static u_int atmel_get_mctrl(struct uart_port *port) > */ > static void atmel_stop_tx(struct uart_port *port) > { > + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); > + > if (atmel_use_dma_tx(port)) { > /* disable PDC transmit */ > UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS); > - UART_PUT_IDR(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE); > - } else > - UART_PUT_IDR(port, ATMEL_US_TXRDY); > + } > + /* Disable interrupts */ > + UART_PUT_IDR(port, atmel_port->tx_done_mask); > + > + if (atmel_port->rs485.flags & SER_RS485_ENABLED) > + atmel_start_rx(port); > } > > /* > @@ -281,17 +382,39 @@ static void atmel_stop_tx(struct uart_port *port) > */ > static void atmel_start_tx(struct uart_port *port) > { > + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); > + > if (atmel_use_dma_tx(port)) { > if (UART_GET_PTSR(port) & ATMEL_PDC_TXTEN) > /* The transmitter is already running. Yes, we > really need this.*/ > return; > > - UART_PUT_IER(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE); > + if (atmel_port->rs485.flags & SER_RS485_ENABLED) > + atmel_stop_rx(port); > + > /* re-enable PDC transmit */ > UART_PUT_PTCR(port, ATMEL_PDC_TXTEN); > - } else > - UART_PUT_IER(port, ATMEL_US_TXRDY); > + } > + /* Enable interrupts */ > + UART_PUT_IER(port, atmel_port->tx_done_mask); > +} > + > +/* > + * start receiving - port is in process of being opened. > + */ > +static void atmel_start_rx(struct uart_port *port) > +{ > + UART_PUT_CR(port, ATMEL_US_RSTSTA); /* reset status and receiver */ > + > + if (atmel_use_dma_rx(port)) { > + /* enable PDC controller */ > + UART_PUT_IER(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT | \ > + port->read_status_mask); > + UART_PUT_PTCR(port, ATMEL_PDC_RXTEN); > + } else { > + UART_PUT_IER(port, ATMEL_US_RXRDY); > + } > } > > /* > @@ -302,9 +425,11 @@ static void atmel_stop_rx(struct uart_port *port) > if (atmel_use_dma_rx(port)) { > /* disable PDC receive */ > UART_PUT_PTCR(port, ATMEL_PDC_RXTDIS); > - UART_PUT_IDR(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT); > - } else > + UART_PUT_IDR(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT | \ > + port->read_status_mask); > + } else { > UART_PUT_IDR(port, ATMEL_US_RXRDY); > + } > } > > /* > @@ -428,8 +553,9 @@ static void atmel_rx_chars(struct uart_port *port) > static void atmel_tx_chars(struct uart_port *port) > { > struct circ_buf *xmit = &port->state->xmit; > + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); > > - if (port->x_char && UART_GET_CSR(port) & ATMEL_US_TXRDY) { > + if (port->x_char && UART_GET_CSR(port) & atmel_port->tx_done_mask) { > UART_PUT_CHAR(port, port->x_char); > port->icount.tx++; > port->x_char = 0; > @@ -437,7 +563,7 @@ static void atmel_tx_chars(struct uart_port *port) > if (uart_circ_empty(xmit) || uart_tx_stopped(port)) > return; > > - while (UART_GET_CSR(port) & ATMEL_US_TXRDY) { > + while (UART_GET_CSR(port) & atmel_port->tx_done_mask) { > UART_PUT_CHAR(port, xmit->buf[xmit->tail]); > xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); > port->icount.tx++; > @@ -449,7 +575,8 @@ static void atmel_tx_chars(struct uart_port *port) > uart_write_wakeup(port); > > if (!uart_circ_empty(xmit)) > - UART_PUT_IER(port, ATMEL_US_TXRDY); > + /* Enable interrupts */ > + UART_PUT_IER(port, atmel_port->tx_done_mask); > } > > /* > @@ -501,18 +628,10 @@ atmel_handle_transmit(struct uart_port *port, unsigned int pending) > { > struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); > > - if (atmel_use_dma_tx(port)) { > - /* PDC transmit */ > - if (pending & (ATMEL_US_ENDTX | ATMEL_US_TXBUFE)) { > - UART_PUT_IDR(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE); > - tasklet_schedule(&atmel_port->tasklet); > - } > - } else { > - /* Interrupt transmit */ > - if (pending & ATMEL_US_TXRDY) { > - UART_PUT_IDR(port, ATMEL_US_TXRDY); > - tasklet_schedule(&atmel_port->tasklet); > - } > + if (pending & atmel_port->tx_done_mask) { > + /* Either PDC or interrupt transmission */ > + UART_PUT_IDR(port, atmel_port->tx_done_mask); > + tasklet_schedule(&atmel_port->tasklet); > } > } > > @@ -590,9 +709,15 @@ static void atmel_tx_dma(struct uart_port *port) > > UART_PUT_TPR(port, pdc->dma_addr + xmit->tail); > UART_PUT_TCR(port, count); > - /* re-enable PDC transmit and interrupts */ > + /* re-enable PDC transmit */ > UART_PUT_PTCR(port, ATMEL_PDC_TXTEN); > - UART_PUT_IER(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE); > + /* Enable interrupts */ > + UART_PUT_IER(port, atmel_port->tx_done_mask); > + } else { > + if (atmel_port->rs485.flags & SER_RS485_ENABLED) { > + /* DMA done, stop TX, start RX for RS485 */ > + atmel_start_rx(port); > + } > } > > if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) > @@ -1017,6 +1142,7 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios, > { > unsigned long flags; > unsigned int mode, imr, quot, baud; > + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); > > /* Get current mode register */ > mode = UART_GET_MR(port) & ~(ATMEL_US_USCLKS | ATMEL_US_CHRL > @@ -1115,6 +1241,17 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios, > /* disable receiver and transmitter */ > UART_PUT_CR(port, ATMEL_US_TXDIS | ATMEL_US_RXDIS); > > + /* Resetting serial mode to RS232 (0x0) */ > + mode &= ~ATMEL_US_USMODE; > + > + if (atmel_port->rs485.flags & SER_RS485_ENABLED) { > + dev_dbg(port->dev, "Keeping UART to RS485\n"); > + UART_PUT_TTGR(port, atmel_port->rs485.delay_rts_before_send); > + mode |= ATMEL_US_USMODE_RS485; > + } else { > + dev_dbg(port->dev, "Keeping UART to RS232\n"); > + } > + > /* set the parity, stop bits and data size */ > UART_PUT_MR(port, mode); > > @@ -1231,6 +1368,30 @@ static void atmel_poll_put_char(struct uart_port *port, unsigned char ch) > } > #endif > > +static int > +atmel_ioctl(struct uart_port *port, unsigned int cmd, unsigned long arg) > +{ > + struct serial_rs485 rs485conf; > + > + switch (cmd) { > + case TIOCSRS485: > + if (copy_from_user(&rs485conf, (struct serial_rs485 *) arg, \ > + sizeof(rs485conf))) > + return -EFAULT; > + > + dev_dbg(port->dev, "enable e/o disable rs485\n"); You could remove this dev_dbg since amtel_config_rs485 already prints debug information. > + > + atmel_config_rs485(port, &rs485conf); > + break; > + > + default: > + return -ENOIOCTLCMD; > + } > + return 0; > +} > + > + > + > static struct uart_ops atmel_pops = { > .tx_empty = atmel_tx_empty, > .set_mctrl = atmel_set_mctrl, > @@ -1250,6 +1411,7 @@ static struct uart_ops atmel_pops = { > .config_port = atmel_config_port, > .verify_port = atmel_verify_port, > .pm = atmel_serial_pm, > + .ioctl = atmel_ioctl, > #ifdef CONFIG_CONSOLE_POLL > .poll_get_char = atmel_poll_get_char, > .poll_put_char = atmel_poll_put_char, > @@ -1265,13 +1427,12 @@ static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port, > struct uart_port *port = &atmel_port->uart; > struct atmel_uart_data *data = pdev->dev.platform_data; > > - port->iotype = UPIO_MEM; > - port->flags = UPF_BOOT_AUTOCONF; > - port->ops = &atmel_pops; > - port->fifosize = 1; > - port->line = pdev->id; > - port->dev = &pdev->dev; > - > + port->iotype = UPIO_MEM; > + port->flags = UPF_BOOT_AUTOCONF; > + port->ops = &atmel_pops; > + port->fifosize = 1; > + port->line = pdev->id; > + port->dev = &pdev->dev; > port->mapbase = pdev->resource[0].start; > port->irq = pdev->resource[1].start; > > @@ -1299,8 +1460,16 @@ static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port, > > atmel_port->use_dma_rx = data->use_dma_rx; > atmel_port->use_dma_tx = data->use_dma_tx; > - if (atmel_use_dma_tx(port)) > + atmel_port->rs485 = data->rs485; > + /* Use TXEMPTY for interrupt when rs485 else TXRDY or ENDTX|TXBUFE */ > + if (atmel_port->rs485.flags & SER_RS485_ENABLED) > + atmel_port->tx_done_mask = ATMEL_US_TXEMPTY; > + else if (atmel_use_dma_tx(port)) { > port->fifosize = PDC_BUFFER_SIZE; > + atmel_port->tx_done_mask = ATMEL_US_ENDTX | ATMEL_US_TXBUFE; > + } else { > + atmel_port->tx_done_mask = ATMEL_US_TXRDY; > + } > } > > /* > @@ -1334,6 +1503,7 @@ static void atmel_console_putchar(struct uart_port *port, int ch) > static void atmel_console_write(struct console *co, const char *s, u_int count) > { > struct uart_port *port = &atmel_ports[co->index].uart; > + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); > unsigned int status, imr; > unsigned int pdc_tx; > > @@ -1341,7 +1511,7 @@ static void atmel_console_write(struct console *co, const char *s, u_int count) > * First, save IMR and then disable interrupts > */ > imr = UART_GET_IMR(port); > - UART_PUT_IDR(port, ATMEL_US_RXRDY | ATMEL_US_TXRDY); > + UART_PUT_IDR(port, ATMEL_US_RXRDY | atmel_port->tx_done_mask); > > /* Store PDC transmit status and disable it */ > pdc_tx = UART_GET_PTSR(port) & ATMEL_PDC_TXTEN; > @@ -1355,7 +1525,7 @@ static void atmel_console_write(struct console *co, const char *s, u_int count) > */ > do { > status = UART_GET_CSR(port); > - } while (!(status & ATMEL_US_TXRDY)); > + } while (!(status & atmel_port->tx_done_mask)); > > /* Restore PDC transmit status */ > if (pdc_tx) > @@ -1587,7 +1757,7 @@ static int __devinit atmel_serial_probe(struct platform_device *pdev) > device_init_wakeup(&pdev->dev, 1); > platform_set_drvdata(pdev, port); > > - return 0; > + return device_create_file(&(pdev->dev), &dev_attr_rs485); > > err_add_port: > kfree(port->rx_ring.buf); > @@ -1619,6 +1789,8 @@ static int __devexit atmel_serial_remove(struct platform_device *pdev) > > clk_put(atmel_port->clk); > > + device_remove_file(&(pdev->dev), &dev_attr_rs485); > + > return ret; > } > ~Ryan -- Bluewater Systems Ltd - ARM Technology Solution Centre Ryan Mallon 5 Amuri Park, 404 Barbadoes St ryan(a)bluewatersys.com PO Box 13 889, Christchurch 8013 http://www.bluewatersys.com New Zealand Phone: +64 3 3779127 Freecall: Australia 1800 148 751 Fax: +64 3 3779135 USA 1800 261 2934 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Claudio Scordino on 30 Mar 2010 05:10 Ryan Mallon ha scritto: > Claudio Scordino wrote: >> Hi all, >> >> this is the new version of the patch to add RS485 support to the >> atmel_serial driver. It's been changed according to Ryan Mallon's >> comments. >> >> This new patch has been tested again (with and without DMA) by Sebastian >> Heutling (CC:-ed). > > A few more, mostly nitpicky, comments below. Hi Ryan, many thanks for your feedback. Please find attached a new version of the patch, modified according to your comments. Regards, Claudio atmel_serial: Atmel RS485 support Signed-off-by: Claudio Scordino <claudio(a)evidence.eu.com> Signed-off-by: Michael Trimarchi <michael(a)evidence.eu.com> Signed-off-by: Rick Bronson <rick(a)efn.org> Signed-off-by: Sebastian Heutling <Sebastian.Heutling(a)who-ing.de> --- arch/arm/include/asm/ioctls.h | 2 + arch/arm/mach-at91/include/mach/board.h | 8 +- drivers/serial/atmel_serial.c | 241 ++++++++++++++++++++++++++----- 3 files changed, 212 insertions(+), 39 deletions(-) diff --git a/arch/arm/include/asm/ioctls.h b/arch/arm/include/asm/ioctls.h index a91d8a1..82f2177 100644 --- a/arch/arm/include/asm/ioctls.h +++ b/arch/arm/include/asm/ioctls.h @@ -70,6 +70,8 @@ #define TIOCGICOUNT 0x545D /* read serial port inline interrupt counts */ #define FIOQSIZE 0x545E +#define TIOCSRS485 0x5461 + /* Used for packet mode */ #define TIOCPKT_DATA 0 #define TIOCPKT_FLUSHREAD 1 diff --git a/arch/arm/mach-at91/include/mach/board.h b/arch/arm/mach-at91/include/mach/board.h index ceaec6c..df2ed84 100644 --- a/arch/arm/mach-at91/include/mach/board.h +++ b/arch/arm/mach-at91/include/mach/board.h @@ -39,6 +39,7 @@ #include <linux/usb/atmel_usba_udc.h> #include <linux/atmel-mci.h> #include <sound/atmel-ac97c.h> +#include <linux/serial.h> /* USB Device */ struct at91_udc_data { @@ -143,9 +144,10 @@ extern struct platform_device *atmel_default_console_device; extern void __init __deprecated at91_init_serial(struct at91_uart_config *config); struct atmel_uart_data { - short use_dma_tx; /* use transmit DMA? */ - short use_dma_rx; /* use receive DMA? */ - void __iomem *regs; /* virtual base address, if any */ + short use_dma_tx; /* use transmit DMA? */ + short use_dma_rx; /* use receive DMA? */ + void __iomem *regs; /* virt. base address, if any */ + struct serial_rs485 rs485; /* rs485 settings */ }; extern void __init at91_add_device_serial(void); diff --git a/drivers/serial/atmel_serial.c b/drivers/serial/atmel_serial.c index 2c9bf9b..039cd65 100644 --- a/drivers/serial/atmel_serial.c +++ b/drivers/serial/atmel_serial.c @@ -38,6 +38,7 @@ #include <linux/dma-mapping.h> #include <linux/atmel_pdc.h> #include <linux/atmel_serial.h> +#include <linux/uaccess.h> #include <asm/io.h> @@ -59,6 +60,9 @@ #include <linux/serial_core.h> +static void atmel_start_rx(struct uart_port *port); +static void atmel_stop_rx(struct uart_port *port); + #ifdef CONFIG_SERIAL_ATMEL_TTYAT /* Use device name ttyAT, major 204 and minor 154-169. This is necessary if we @@ -93,6 +97,7 @@ #define UART_GET_BRGR(port) __raw_readl((port)->membase + ATMEL_US_BRGR) #define UART_PUT_BRGR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_BRGR) #define UART_PUT_RTOR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_RTOR) +#define UART_PUT_TTGR(port, v) __raw_writel(v, (port)->membase + ATMEL_US_TTGR) /* PDC registers */ #define UART_PUT_PTCR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_PTCR) @@ -147,6 +152,9 @@ struct atmel_uart_port { unsigned int irq_status_prev; struct circ_buf rx_ring; + + struct serial_rs485 rs485; /* rs485 settings */ + unsigned int tx_done_mask; }; static struct atmel_uart_port atmel_ports[ATMEL_MAX_UART]; @@ -187,6 +195,81 @@ static bool atmel_use_dma_tx(struct uart_port *port) } #endif +/* Enable or disable the rs485 support */ +void atmel_config_rs485(struct uart_port *port, struct serial_rs485 *rs485conf) +{ + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); + unsigned long flags; + unsigned int mode; + + spin_lock_irqsave(&port->lock, flags); + + mode = UART_GET_MR(port); + + /* Resetting serial mode to RS232 (0x0) */ + mode &= ~ATMEL_US_USMODE; + + atmel_port->rs485 = *rs485conf; + + if (rs485conf->flags & SER_RS485_ENABLED) { + dev_dbg(port->dev, "Setting UART to RS485\n"); + atmel_port->tx_done_mask = ATMEL_US_TXEMPTY; + UART_PUT_TTGR(port, rs485conf->delay_rts_before_send); + mode |= ATMEL_US_USMODE_RS485; + } else { + dev_dbg(port->dev, "Setting UART to RS232\n"); + if (atmel_use_dma_tx(port)) + atmel_port->tx_done_mask = ATMEL_US_ENDTX | + ATMEL_US_TXBUFE; + else + atmel_port->tx_done_mask = ATMEL_US_TXRDY; + } + UART_PUT_MR(port, mode); + + spin_unlock_irqrestore(&port->lock, flags); +} + + +static ssize_t show_rs485(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct platform_device *pdev = to_platform_device(dev); + struct uart_port *port = platform_get_drvdata(pdev); + unsigned int current_mode; + + current_mode = UART_GET_MR(port) & ATMEL_US_USMODE; + return snprintf(buf, PAGE_SIZE, "%u\n", current_mode); +} + +static ssize_t set_rs485(struct device *dev, struct device_attribute *attr, + const char *buf, size_t len) +{ + struct platform_device *pdev = to_platform_device(dev); + struct uart_port *port = platform_get_drvdata(pdev); + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); + struct serial_rs485 rs485conf = atmel_port->rs485; + unsigned int value; + + if (!buf) + return -EINVAL; + + value = !!(simple_strtoul(buf, NULL, 0)); + + if (value) { + rs485conf.flags |= SER_RS485_ENABLED; + /* 0x4 is the normal reset value. */ + rs485conf.delay_rts_before_send = 0x00000004; + } else { + rs485conf.flags &= ~SER_RS485_ENABLED; + } + + atmel_config_rs485(port, &rs485conf); + + return strnlen(buf, PAGE_SIZE); +} + +static DEVICE_ATTR(rs485, 0644, show_rs485, set_rs485); + /* * Return TIOCSER_TEMT when transmitter FIFO and Shift register is empty. */ @@ -202,6 +285,7 @@ static void atmel_set_mctrl(struct uart_port *port, u_int mctrl) { unsigned int control = 0; unsigned int mode; + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); #ifdef CONFIG_ARCH_AT91RM9200 if (cpu_is_at91rm9200()) { @@ -236,6 +320,17 @@ static void atmel_set_mctrl(struct uart_port *port, u_int mctrl) mode |= ATMEL_US_CHMODE_LOC_LOOP; else mode |= ATMEL_US_CHMODE_NORMAL; + + /* Resetting serial mode to RS232 (0x0) */ + mode &= ~ATMEL_US_USMODE; + + if (atmel_port->rs485.flags & SER_RS485_ENABLED) { + dev_dbg(port->dev, "Setting UART to RS485\n"); + UART_PUT_TTGR(port, atmel_port->rs485.delay_rts_before_send); + mode |= ATMEL_US_USMODE_RS485; + } else { + dev_dbg(port->dev, "Setting UART to RS232\n"); + } UART_PUT_MR(port, mode); } @@ -268,12 +363,17 @@ static u_int atmel_get_mctrl(struct uart_port *port) */ static void atmel_stop_tx(struct uart_port *port) { + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); + if (atmel_use_dma_tx(port)) { /* disable PDC transmit */ UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS); - UART_PUT_IDR(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE); - } else - UART_PUT_IDR(port, ATMEL_US_TXRDY); + } + /* Disable interrupts */ + UART_PUT_IDR(port, atmel_port->tx_done_mask); + + if (atmel_port->rs485.flags & SER_RS485_ENABLED) + atmel_start_rx(port); } /* @@ -281,17 +381,39 @@ static void atmel_stop_tx(struct uart_port *port) */ static void atmel_start_tx(struct uart_port *port) { + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); + if (atmel_use_dma_tx(port)) { if (UART_GET_PTSR(port) & ATMEL_PDC_TXTEN) /* The transmitter is already running. Yes, we really need this.*/ return; - UART_PUT_IER(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE); + if (atmel_port->rs485.flags & SER_RS485_ENABLED) + atmel_stop_rx(port); + /* re-enable PDC transmit */ UART_PUT_PTCR(port, ATMEL_PDC_TXTEN); - } else - UART_PUT_IER(port, ATMEL_US_TXRDY); + } + /* Enable interrupts */ + UART_PUT_IER(port, atmel_port->tx_done_mask); +} + +/* + * start receiving - port is in process of being opened. + */ +static void atmel_start_rx(struct uart_port *port) +{ + UART_PUT_CR(port, ATMEL_US_RSTSTA); /* reset status and receiver */ + + if (atmel_use_dma_rx(port)) { + /* enable PDC controller */ + UART_PUT_IER(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT | + port->read_status_mask); + UART_PUT_PTCR(port, ATMEL_PDC_RXTEN); + } else { + UART_PUT_IER(port, ATMEL_US_RXRDY); + } } /* @@ -302,9 +424,11 @@ static void atmel_stop_rx(struct uart_port *port) if (atmel_use_dma_rx(port)) { /* disable PDC receive */ UART_PUT_PTCR(port, ATMEL_PDC_RXTDIS); - UART_PUT_IDR(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT); - } else + UART_PUT_IDR(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT | + port->read_status_mask); + } else { UART_PUT_IDR(port, ATMEL_US_RXRDY); + } } /* @@ -428,8 +552,9 @@ static void atmel_rx_chars(struct uart_port *port) static void atmel_tx_chars(struct uart_port *port) { struct circ_buf *xmit = &port->state->xmit; + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); - if (port->x_char && UART_GET_CSR(port) & ATMEL_US_TXRDY) { + if (port->x_char && UART_GET_CSR(port) & atmel_port->tx_done_mask) { UART_PUT_CHAR(port, port->x_char); port->icount.tx++; port->x_char = 0; @@ -437,7 +562,7 @@ static void atmel_tx_chars(struct uart_port *port) if (uart_circ_empty(xmit) || uart_tx_stopped(port)) return; - while (UART_GET_CSR(port) & ATMEL_US_TXRDY) { + while (UART_GET_CSR(port) & atmel_port->tx_done_mask) { UART_PUT_CHAR(port, xmit->buf[xmit->tail]); xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); port->icount.tx++; @@ -449,7 +574,8 @@ static void atmel_tx_chars(struct uart_port *port) uart_write_wakeup(port); if (!uart_circ_empty(xmit)) - UART_PUT_IER(port, ATMEL_US_TXRDY); + /* Enable interrupts */ + UART_PUT_IER(port, atmel_port->tx_done_mask); } /* @@ -501,18 +627,10 @@ atmel_handle_transmit(struct uart_port *port, unsigned int pending) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); - if (atmel_use_dma_tx(port)) { - /* PDC transmit */ - if (pending & (ATMEL_US_ENDTX | ATMEL_US_TXBUFE)) { - UART_PUT_IDR(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE); - tasklet_schedule(&atmel_port->tasklet); - } - } else { - /* Interrupt transmit */ - if (pending & ATMEL_US_TXRDY) { - UART_PUT_IDR(port, ATMEL_US_TXRDY); - tasklet_schedule(&atmel_port->tasklet); - } + if (pending & atmel_port->tx_done_mask) { + /* Either PDC or interrupt transmission */ + UART_PUT_IDR(port, atmel_port->tx_done_mask); + tasklet_schedule(&atmel_port->tasklet); } } @@ -590,9 +708,15 @@ static void atmel_tx_dma(struct uart_port *port) UART_PUT_TPR(port, pdc->dma_addr + xmit->tail); UART_PUT_TCR(port, count); - /* re-enable PDC transmit and interrupts */ + /* re-enable PDC transmit */ UART_PUT_PTCR(port, ATMEL_PDC_TXTEN); - UART_PUT_IER(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE); + /* Enable interrupts */ + UART_PUT_IER(port, atmel_port->tx_done_mask); + } else { + if (atmel_port->rs485.flags & SER_RS485_ENABLED) { + /* DMA done, stop TX, start RX for RS485 */ + atmel_start_rx(port); + } } if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) @@ -1017,6 +1141,7 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios, { unsigned long flags; unsigned int mode, imr, quot, baud; + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); /* Get current mode register */ mode = UART_GET_MR(port) & ~(ATMEL_US_USCLKS | ATMEL_US_CHRL @@ -1115,6 +1240,17 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios, /* disable receiver and transmitter */ UART_PUT_CR(port, ATMEL_US_TXDIS | ATMEL_US_RXDIS); + /* Resetting serial mode to RS232 (0x0) */ + mode &= ~ATMEL_US_USMODE; + + if (atmel_port->rs485.flags & SER_RS485_ENABLED) { + dev_dbg(port->dev, "Setting UART to RS485\n"); + UART_PUT_TTGR(port, atmel_port->rs485.delay_rts_before_send); + mode |= ATMEL_US_USMODE_RS485; + } else { + dev_dbg(port->dev, "Setting UART to RS232\n"); + } + /* set the parity, stop bits and data size */ UART_PUT_MR(port, mode); @@ -1231,6 +1367,28 @@ static void atmel_poll_put_char(struct uart_port *port, unsigned char ch) } #endif +static int +atmel_ioctl(struct uart_port *port, unsigned int cmd, unsigned long arg) +{ + struct serial_rs485 rs485conf; + + switch (cmd) { + case TIOCSRS485: + if (copy_from_user(&rs485conf, (struct serial_rs485 *) arg, + sizeof(rs485conf))) + return -EFAULT; + + atmel_config_rs485(port, &rs485conf); + break; + + default: + return -ENOIOCTLCMD; + } + return 0; +} + + + static struct uart_ops atmel_pops = { .tx_empty = atmel_tx_empty, .set_mctrl = atmel_set_mctrl, @@ -1250,6 +1408,7 @@ static struct uart_ops atmel_pops = { .config_port = atmel_config_port, .verify_port = atmel_verify_port, .pm = atmel_serial_pm, + .ioctl = atmel_ioctl, #ifdef CONFIG_CONSOLE_POLL .poll_get_char = atmel_poll_get_char, .poll_put_char = atmel_poll_put_char, @@ -1265,13 +1424,12 @@ static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port, struct uart_port *port = &atmel_port->uart; struct atmel_uart_data *data = pdev->dev.platform_data; - port->iotype = UPIO_MEM; - port->flags = UPF_BOOT_AUTOCONF; - port->ops = &atmel_pops; - port->fifosize = 1; - port->line = pdev->id; - port->dev = &pdev->dev; - + port->iotype = UPIO_MEM; + port->flags = UPF_BOOT_AUTOCONF; + port->ops = &atmel_pops; + port->fifosize = 1; + port->line = pdev->id; + port->dev = &pdev->dev; port->mapbase = pdev->resource[0].start; port->irq = pdev->resource[1].start; @@ -1299,8 +1457,16 @@ static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port, atmel_port->use_dma_rx = data->use_dma_rx; atmel_port->use_dma_tx = data->use_dma_tx; - if (atmel_use_dma_tx(port)) + atmel_port->rs485 = data->rs485; + /* Use TXEMPTY for interrupt when rs485 else TXRDY or ENDTX|TXBUFE */ + if (atmel_port->rs485.flags & SER_RS485_ENABLED) + atmel_port->tx_done_mask = ATMEL_US_TXEMPTY; + else if (atmel_use_dma_tx(port)) { port->fifosize = PDC_BUFFER_SIZE; + atmel_port->tx_done_mask = ATMEL_US_ENDTX | ATMEL_US_TXBUFE; + } else { + atmel_port->tx_done_mask = ATMEL_US_TXRDY; + } } /* @@ -1334,6 +1500,7 @@ static void atmel_console_putchar(struct uart_port *port, int ch) static void atmel_console_write(struct console *co, const char *s, u_int count) { struct uart_port *port = &atmel_ports[co->index].uart; + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); unsigned int status, imr; unsigned int pdc_tx; @@ -1341,7 +1508,7 @@ static void atmel_console_write(struct console *co, const char *s, u_int count) * First, save IMR and then disable interrupts */ imr = UART_GET_IMR(port); - UART_PUT_IDR(port, ATMEL_US_RXRDY | ATMEL_US_TXRDY); + UART_PUT_IDR(port, ATMEL_US_RXRDY | atmel_port->tx_done_mask); /* Store PDC transmit status and disable it */ pdc_tx = UART_GET_PTSR(port) & ATMEL_PDC_TXTEN; @@ -1355,7 +1522,7 @@ static void atmel_console_write(struct console *co, const char *s, u_int count) */ do { status = UART_GET_CSR(port); - } while (!(status & ATMEL_US_TXRDY)); + } while (!(status & atmel_port->tx_done_mask)); /* Restore PDC transmit status */ if (pdc_tx) @@ -1587,7 +1754,7 @@ static int __devinit atmel_serial_probe(struct platform_device *pdev) device_init_wakeup(&pdev->dev, 1); platform_set_drvdata(pdev, port); - return 0; + return device_create_file(&(pdev->dev), &dev_attr_rs485); err_add_port: kfree(port->rx_ring.buf); @@ -1619,6 +1786,8 @@ static int __devexit atmel_serial_remove(struct platform_device *pdev) clk_put(atmel_port->clk); + device_remove_file(&(pdev->dev), &dev_attr_rs485); + return ret; } -- 1.6.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Ryan Mallon on 30 Mar 2010 15:40 Claudio Scordino wrote: > Ryan Mallon ha scritto: >> Claudio Scordino wrote: >>> Hi all, >>> >>> this is the new version of the patch to add RS485 support to the >>> atmel_serial driver. It's been changed according to Ryan Mallon's >>> comments. >>> >>> This new patch has been tested again (with and without DMA) by Sebastian >>> Heutling (CC:-ed). >> A few more, mostly nitpicky, comments below. > > Hi Ryan, > > many thanks for your feedback. > > Please find attached a new version of the patch, modified according to > your comments. Looks good. You should add a Tested-by for Sebastian, and you can add: Reviewed-by: Ryan Mallon <ryan(a)bluewatersys.com> ~Ryan > Regards, > > Claudio > > > atmel_serial: Atmel RS485 support > > Signed-off-by: Claudio Scordino <claudio(a)evidence.eu.com> > Signed-off-by: Michael Trimarchi <michael(a)evidence.eu.com> > Signed-off-by: Rick Bronson <rick(a)efn.org> > Signed-off-by: Sebastian Heutling <Sebastian.Heutling(a)who-ing.de> > --- > arch/arm/include/asm/ioctls.h | 2 + > arch/arm/mach-at91/include/mach/board.h | 8 +- > drivers/serial/atmel_serial.c | 241 ++++++++++++++++++++++++++----- > 3 files changed, 212 insertions(+), 39 deletions(-) > > diff --git a/arch/arm/include/asm/ioctls.h b/arch/arm/include/asm/ioctls.h > index a91d8a1..82f2177 100644 > --- a/arch/arm/include/asm/ioctls.h > +++ b/arch/arm/include/asm/ioctls.h > @@ -70,6 +70,8 @@ > #define TIOCGICOUNT 0x545D /* read serial port inline interrupt counts */ > #define FIOQSIZE 0x545E > > +#define TIOCSRS485 0x5461 > + > /* Used for packet mode */ > #define TIOCPKT_DATA 0 > #define TIOCPKT_FLUSHREAD 1 > diff --git a/arch/arm/mach-at91/include/mach/board.h b/arch/arm/mach-at91/include/mach/board.h > index ceaec6c..df2ed84 100644 > --- a/arch/arm/mach-at91/include/mach/board.h > +++ b/arch/arm/mach-at91/include/mach/board.h > @@ -39,6 +39,7 @@ > #include <linux/usb/atmel_usba_udc.h> > #include <linux/atmel-mci.h> > #include <sound/atmel-ac97c.h> > +#include <linux/serial.h> > > /* USB Device */ > struct at91_udc_data { > @@ -143,9 +144,10 @@ extern struct platform_device *atmel_default_console_device; > extern void __init __deprecated at91_init_serial(struct at91_uart_config *config); > > struct atmel_uart_data { > - short use_dma_tx; /* use transmit DMA? */ > - short use_dma_rx; /* use receive DMA? */ > - void __iomem *regs; /* virtual base address, if any */ > + short use_dma_tx; /* use transmit DMA? */ > + short use_dma_rx; /* use receive DMA? */ > + void __iomem *regs; /* virt. base address, if any */ > + struct serial_rs485 rs485; /* rs485 settings */ > }; > extern void __init at91_add_device_serial(void); > > diff --git a/drivers/serial/atmel_serial.c b/drivers/serial/atmel_serial.c > index 2c9bf9b..039cd65 100644 > --- a/drivers/serial/atmel_serial.c > +++ b/drivers/serial/atmel_serial.c > @@ -38,6 +38,7 @@ > #include <linux/dma-mapping.h> > #include <linux/atmel_pdc.h> > #include <linux/atmel_serial.h> > +#include <linux/uaccess.h> > > #include <asm/io.h> > > @@ -59,6 +60,9 @@ > > #include <linux/serial_core.h> > > +static void atmel_start_rx(struct uart_port *port); > +static void atmel_stop_rx(struct uart_port *port); > + > #ifdef CONFIG_SERIAL_ATMEL_TTYAT > > /* Use device name ttyAT, major 204 and minor 154-169. This is necessary if we > @@ -93,6 +97,7 @@ > #define UART_GET_BRGR(port) __raw_readl((port)->membase + ATMEL_US_BRGR) > #define UART_PUT_BRGR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_BRGR) > #define UART_PUT_RTOR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_RTOR) > +#define UART_PUT_TTGR(port, v) __raw_writel(v, (port)->membase + ATMEL_US_TTGR) > > /* PDC registers */ > #define UART_PUT_PTCR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_PTCR) > @@ -147,6 +152,9 @@ struct atmel_uart_port { > unsigned int irq_status_prev; > > struct circ_buf rx_ring; > + > + struct serial_rs485 rs485; /* rs485 settings */ > + unsigned int tx_done_mask; > }; > > static struct atmel_uart_port atmel_ports[ATMEL_MAX_UART]; > @@ -187,6 +195,81 @@ static bool atmel_use_dma_tx(struct uart_port *port) > } > #endif > > +/* Enable or disable the rs485 support */ > +void atmel_config_rs485(struct uart_port *port, struct serial_rs485 *rs485conf) > +{ > + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); > + unsigned long flags; > + unsigned int mode; > + > + spin_lock_irqsave(&port->lock, flags); > + > + mode = UART_GET_MR(port); > + > + /* Resetting serial mode to RS232 (0x0) */ > + mode &= ~ATMEL_US_USMODE; > + > + atmel_port->rs485 = *rs485conf; > + > + if (rs485conf->flags & SER_RS485_ENABLED) { > + dev_dbg(port->dev, "Setting UART to RS485\n"); > + atmel_port->tx_done_mask = ATMEL_US_TXEMPTY; > + UART_PUT_TTGR(port, rs485conf->delay_rts_before_send); > + mode |= ATMEL_US_USMODE_RS485; > + } else { > + dev_dbg(port->dev, "Setting UART to RS232\n"); > + if (atmel_use_dma_tx(port)) > + atmel_port->tx_done_mask = ATMEL_US_ENDTX | > + ATMEL_US_TXBUFE; > + else > + atmel_port->tx_done_mask = ATMEL_US_TXRDY; > + } > + UART_PUT_MR(port, mode); > + > + spin_unlock_irqrestore(&port->lock, flags); > +} > + > + > +static ssize_t show_rs485(struct device *dev, struct device_attribute *attr, > + char *buf) > +{ > + struct platform_device *pdev = to_platform_device(dev); > + struct uart_port *port = platform_get_drvdata(pdev); > + unsigned int current_mode; > + > + current_mode = UART_GET_MR(port) & ATMEL_US_USMODE; > + return snprintf(buf, PAGE_SIZE, "%u\n", current_mode); > +} > + > +static ssize_t set_rs485(struct device *dev, struct device_attribute *attr, > + const char *buf, size_t len) > +{ > + struct platform_device *pdev = to_platform_device(dev); > + struct uart_port *port = platform_get_drvdata(pdev); > + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); > + struct serial_rs485 rs485conf = atmel_port->rs485; > + unsigned int value; > + > + if (!buf) > + return -EINVAL; > + > + value = !!(simple_strtoul(buf, NULL, 0)); > + > + if (value) { > + rs485conf.flags |= SER_RS485_ENABLED; > + /* 0x4 is the normal reset value. */ > + rs485conf.delay_rts_before_send = 0x00000004; > + } else { > + rs485conf.flags &= ~SER_RS485_ENABLED; > + } > + > + atmel_config_rs485(port, &rs485conf); > + > + return strnlen(buf, PAGE_SIZE); > +} > + > +static DEVICE_ATTR(rs485, 0644, show_rs485, set_rs485); > + > /* > * Return TIOCSER_TEMT when transmitter FIFO and Shift register is empty. > */ > @@ -202,6 +285,7 @@ static void atmel_set_mctrl(struct uart_port *port, u_int mctrl) > { > unsigned int control = 0; > unsigned int mode; > + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); > > #ifdef CONFIG_ARCH_AT91RM9200 > if (cpu_is_at91rm9200()) { > @@ -236,6 +320,17 @@ static void atmel_set_mctrl(struct uart_port *port, u_int mctrl) > mode |= ATMEL_US_CHMODE_LOC_LOOP; > else > mode |= ATMEL_US_CHMODE_NORMAL; > + > + /* Resetting serial mode to RS232 (0x0) */ > + mode &= ~ATMEL_US_USMODE; > + > + if (atmel_port->rs485.flags & SER_RS485_ENABLED) { > + dev_dbg(port->dev, "Setting UART to RS485\n"); > + UART_PUT_TTGR(port, atmel_port->rs485.delay_rts_before_send); > + mode |= ATMEL_US_USMODE_RS485; > + } else { > + dev_dbg(port->dev, "Setting UART to RS232\n"); > + } > UART_PUT_MR(port, mode); > } > > @@ -268,12 +363,17 @@ static u_int atmel_get_mctrl(struct uart_port *port) > */ > static void atmel_stop_tx(struct uart_port *port) > { > + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); > + > if (atmel_use_dma_tx(port)) { > /* disable PDC transmit */ > UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS); > - UART_PUT_IDR(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE); > - } else > - UART_PUT_IDR(port, ATMEL_US_TXRDY); > + } > + /* Disable interrupts */ > + UART_PUT_IDR(port, atmel_port->tx_done_mask); > + > + if (atmel_port->rs485.flags & SER_RS485_ENABLED) > + atmel_start_rx(port); > } > > /* > @@ -281,17 +381,39 @@ static void atmel_stop_tx(struct uart_port *port) > */ > static void atmel_start_tx(struct uart_port *port) > { > + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); > + > if (atmel_use_dma_tx(port)) { > if (UART_GET_PTSR(port) & ATMEL_PDC_TXTEN) > /* The transmitter is already running. Yes, we > really need this.*/ > return; > > - UART_PUT_IER(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE); > + if (atmel_port->rs485.flags & SER_RS485_ENABLED) > + atmel_stop_rx(port); > + > /* re-enable PDC transmit */ > UART_PUT_PTCR(port, ATMEL_PDC_TXTEN); > - } else > - UART_PUT_IER(port, ATMEL_US_TXRDY); > + } > + /* Enable interrupts */ > + UART_PUT_IER(port, atmel_port->tx_done_mask); > +} > + > +/* > + * start receiving - port is in process of being opened. > + */ > +static void atmel_start_rx(struct uart_port *port) > +{ > + UART_PUT_CR(port, ATMEL_US_RSTSTA); /* reset status and receiver */ > + > + if (atmel_use_dma_rx(port)) { > + /* enable PDC controller */ > + UART_PUT_IER(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT | > + port->read_status_mask); > + UART_PUT_PTCR(port, ATMEL_PDC_RXTEN); > + } else { > + UART_PUT_IER(port, ATMEL_US_RXRDY); > + } > } > > /* > @@ -302,9 +424,11 @@ static void atmel_stop_rx(struct uart_port *port) > if (atmel_use_dma_rx(port)) { > /* disable PDC receive */ > UART_PUT_PTCR(port, ATMEL_PDC_RXTDIS); > - UART_PUT_IDR(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT); > - } else > + UART_PUT_IDR(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT | > + port->read_status_mask); > + } else { > UART_PUT_IDR(port, ATMEL_US_RXRDY); > + } > } > > /* > @@ -428,8 +552,9 @@ static void atmel_rx_chars(struct uart_port *port) > static void atmel_tx_chars(struct uart_port *port) > { > struct circ_buf *xmit = &port->state->xmit; > + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); > > - if (port->x_char && UART_GET_CSR(port) & ATMEL_US_TXRDY) { > + if (port->x_char && UART_GET_CSR(port) & atmel_port->tx_done_mask) { > UART_PUT_CHAR(port, port->x_char); > port->icount.tx++; > port->x_char = 0; > @@ -437,7 +562,7 @@ static void atmel_tx_chars(struct uart_port *port) > if (uart_circ_empty(xmit) || uart_tx_stopped(port)) > return; > > - while (UART_GET_CSR(port) & ATMEL_US_TXRDY) { > + while (UART_GET_CSR(port) & atmel_port->tx_done_mask) { > UART_PUT_CHAR(port, xmit->buf[xmit->tail]); > xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); > port->icount.tx++; > @@ -449,7 +574,8 @@ static void atmel_tx_chars(struct uart_port *port) > uart_write_wakeup(port); > > if (!uart_circ_empty(xmit)) > - UART_PUT_IER(port, ATMEL_US_TXRDY); > + /* Enable interrupts */ > + UART_PUT_IER(port, atmel_port->tx_done_mask); > } > > /* > @@ -501,18 +627,10 @@ atmel_handle_transmit(struct uart_port *port, unsigned int pending) > { > struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); > > - if (atmel_use_dma_tx(port)) { > - /* PDC transmit */ > - if (pending & (ATMEL_US_ENDTX | ATMEL_US_TXBUFE)) { > - UART_PUT_IDR(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE); > - tasklet_schedule(&atmel_port->tasklet); > - } > - } else { > - /* Interrupt transmit */ > - if (pending & ATMEL_US_TXRDY) { > - UART_PUT_IDR(port, ATMEL_US_TXRDY); > - tasklet_schedule(&atmel_port->tasklet); > - } > + if (pending & atmel_port->tx_done_mask) { > + /* Either PDC or interrupt transmission */ > + UART_PUT_IDR(port, atmel_port->tx_done_mask); > + tasklet_schedule(&atmel_port->tasklet); > } > } > > @@ -590,9 +708,15 @@ static void atmel_tx_dma(struct uart_port *port) > > UART_PUT_TPR(port, pdc->dma_addr + xmit->tail); > UART_PUT_TCR(port, count); > - /* re-enable PDC transmit and interrupts */ > + /* re-enable PDC transmit */ > UART_PUT_PTCR(port, ATMEL_PDC_TXTEN); > - UART_PUT_IER(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE); > + /* Enable interrupts */ > + UART_PUT_IER(port, atmel_port->tx_done_mask); > + } else { > + if (atmel_port->rs485.flags & SER_RS485_ENABLED) { > + /* DMA done, stop TX, start RX for RS485 */ > + atmel_start_rx(port); > + } > } > > if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) > @@ -1017,6 +1141,7 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios, > { > unsigned long flags; > unsigned int mode, imr, quot, baud; > + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); > > /* Get current mode register */ > mode = UART_GET_MR(port) & ~(ATMEL_US_USCLKS | ATMEL_US_CHRL > @@ -1115,6 +1240,17 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios, > /* disable receiver and transmitter */ > UART_PUT_CR(port, ATMEL_US_TXDIS | ATMEL_US_RXDIS); > > + /* Resetting serial mode to RS232 (0x0) */ > + mode &= ~ATMEL_US_USMODE; > + > + if (atmel_port->rs485.flags & SER_RS485_ENABLED) { > + dev_dbg(port->dev, "Setting UART to RS485\n"); > + UART_PUT_TTGR(port, atmel_port->rs485.delay_rts_before_send); > + mode |= ATMEL_US_USMODE_RS485; > + } else { > + dev_dbg(port->dev, "Setting UART to RS232\n"); > + } > + > /* set the parity, stop bits and data size */ > UART_PUT_MR(port, mode); > > @@ -1231,6 +1367,28 @@ static void atmel_poll_put_char(struct uart_port *port, unsigned char ch) > } > #endif > > +static int > +atmel_ioctl(struct uart_port *port, unsigned int cmd, unsigned long arg) > +{ > + struct serial_rs485 rs485conf; > + > + switch (cmd) { > + case TIOCSRS485: > + if (copy_from_user(&rs485conf, (struct serial_rs485 *) arg, > + sizeof(rs485conf))) > + return -EFAULT; > + > + atmel_config_rs485(port, &rs485conf); > + break; > + > + default: > + return -ENOIOCTLCMD; > + } > + return 0; > +} > + > + > + > static struct uart_ops atmel_pops = { > .tx_empty = atmel_tx_empty, > .set_mctrl = atmel_set_mctrl, > @@ -1250,6 +1408,7 @@ static struct uart_ops atmel_pops = { > .config_port = atmel_config_port, > .verify_port = atmel_verify_port, > .pm = atmel_serial_pm, > + .ioctl = atmel_ioctl, > #ifdef CONFIG_CONSOLE_POLL > .poll_get_char = atmel_poll_get_char, > .poll_put_char = atmel_poll_put_char, > @@ -1265,13 +1424,12 @@ static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port, > struct uart_port *port = &atmel_port->uart; > struct atmel_uart_data *data = pdev->dev.platform_data; > > - port->iotype = UPIO_MEM; > - port->flags = UPF_BOOT_AUTOCONF; > - port->ops = &atmel_pops; > - port->fifosize = 1; > - port->line = pdev->id; > - port->dev = &pdev->dev; > - > + port->iotype = UPIO_MEM; > + port->flags = UPF_BOOT_AUTOCONF; > + port->ops = &atmel_pops; > + port->fifosize = 1; > + port->line = pdev->id; > + port->dev = &pdev->dev; > port->mapbase = pdev->resource[0].start; > port->irq = pdev->resource[1].start; > > @@ -1299,8 +1457,16 @@ static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port, > > atmel_port->use_dma_rx = data->use_dma_rx; > atmel_port->use_dma_tx = data->use_dma_tx; > - if (atmel_use_dma_tx(port)) > + atmel_port->rs485 = data->rs485; > + /* Use TXEMPTY for interrupt when rs485 else TXRDY or ENDTX|TXBUFE */ > + if (atmel_port->rs485.flags & SER_RS485_ENABLED) > + atmel_port->tx_done_mask = ATMEL_US_TXEMPTY; > + else if (atmel_use_dma_tx(port)) { > port->fifosize = PDC_BUFFER_SIZE; > + atmel_port->tx_done_mask = ATMEL_US_ENDTX | ATMEL_US_TXBUFE; > + } else { > + atmel_port->tx_done_mask = ATMEL_US_TXRDY; > + } > } > > /* > @@ -1334,6 +1500,7 @@ static void atmel_console_putchar(struct uart_port *port, int ch) > static void atmel_console_write(struct console *co, const char *s, u_int count) > { > struct uart_port *port = &atmel_ports[co->index].uart; > + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); > unsigned int status, imr; > unsigned int pdc_tx; > > @@ -1341,7 +1508,7 @@ static void atmel_console_write(struct console *co, const char *s, u_int count) > * First, save IMR and then disable interrupts > */ > imr = UART_GET_IMR(port); > - UART_PUT_IDR(port, ATMEL_US_RXRDY | ATMEL_US_TXRDY); > + UART_PUT_IDR(port, ATMEL_US_RXRDY | atmel_port->tx_done_mask); > > /* Store PDC transmit status and disable it */ > pdc_tx = UART_GET_PTSR(port) & ATMEL_PDC_TXTEN; > @@ -1355,7 +1522,7 @@ static void atmel_console_write(struct console *co, const char *s, u_int count) > */ > do { > status = UART_GET_CSR(port); > - } while (!(status & ATMEL_US_TXRDY)); > + } while (!(status & atmel_port->tx_done_mask)); > > /* Restore PDC transmit status */ > if (pdc_tx) > @@ -1587,7 +1754,7 @@ static int __devinit atmel_serial_probe(struct platform_device *pdev) > device_init_wakeup(&pdev->dev, 1); > platform_set_drvdata(pdev, port); > > - return 0; > + return device_create_file(&(pdev->dev), &dev_attr_rs485); > > err_add_port: > kfree(port->rx_ring.buf); > @@ -1619,6 +1786,8 @@ static int __devexit atmel_serial_remove(struct platform_device *pdev) > > clk_put(atmel_port->clk); > > + device_remove_file(&(pdev->dev), &dev_attr_rs485); > + > return ret; > } > -- Bluewater Systems Ltd - ARM Technology Solution Centre Ryan Mallon 5 Amuri Park, 404 Barbadoes St ryan(a)bluewatersys.com PO Box 13 889, Christchurch 8013 http://www.bluewatersys.com New Zealand Phone: +64 3 3779127 Freecall: Australia 1800 148 751 Fax: +64 3 3779135 USA 1800 261 2934 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Claudio Scordino on 8 Apr 2010 04:00 Ryan Mallon ha scritto: > Claudio Scordino wrote: >> Ryan Mallon ha scritto: >>> Claudio Scordino wrote: >>>> Hi all, >>>> >>>> this is the new version of the patch to add RS485 support to the >>>> atmel_serial driver. It's been changed according to Ryan Mallon's >>>> comments. >>>> >>>> This new patch has been tested again (with and without DMA) by Sebastian >>>> Heutling (CC:-ed). >>> A few more, mostly nitpicky, comments below. >> Hi Ryan, >> >> many thanks for your feedback. >> >> Please find attached a new version of the patch, modified according to >> your comments. > > Looks good. You should add a Tested-by for Sebastian, and you can add: > > Reviewed-by: Ryan Mallon <ryan(a)bluewatersys.com> > Here it is (I just added the Tested-by and Reviewed-by fields). Best regards, Claudio atmel_serial: Atmel RS485 support Signed-off-by: Claudio Scordino <claudio(a)evidence.eu.com> Signed-off-by: Michael Trimarchi <michael(a)evidence.eu.com> Signed-off-by: Rick Bronson <rick(a)efn.org> Signed-off-by: Sebastian Heutling <Sebastian.Heutling(a)who-ing.de> Tested-by: Sebastian Heutling <Sebastian.Heutling(a)who-ing.de> Reviewed-by: Ryan Mallon <ryan(a)bluewatersys.com> --- arch/arm/include/asm/ioctls.h | 2 + arch/arm/mach-at91/include/mach/board.h | 8 +- drivers/serial/atmel_serial.c | 241 ++++++++++++++++++++++++++----- 3 files changed, 212 insertions(+), 39 deletions(-) diff --git a/arch/arm/include/asm/ioctls.h b/arch/arm/include/asm/ioctls.h index a91d8a1..82f2177 100644 --- a/arch/arm/include/asm/ioctls.h +++ b/arch/arm/include/asm/ioctls.h @@ -70,6 +70,8 @@ #define TIOCGICOUNT 0x545D /* read serial port inline interrupt counts */ #define FIOQSIZE 0x545E +#define TIOCSRS485 0x5461 + /* Used for packet mode */ #define TIOCPKT_DATA 0 #define TIOCPKT_FLUSHREAD 1 diff --git a/arch/arm/mach-at91/include/mach/board.h b/arch/arm/mach-at91/include/mach/board.h index ceaec6c..df2ed84 100644 --- a/arch/arm/mach-at91/include/mach/board.h +++ b/arch/arm/mach-at91/include/mach/board.h @@ -39,6 +39,7 @@ #include <linux/usb/atmel_usba_udc.h> #include <linux/atmel-mci.h> #include <sound/atmel-ac97c.h> +#include <linux/serial.h> /* USB Device */ struct at91_udc_data { @@ -143,9 +144,10 @@ extern struct platform_device *atmel_default_console_device; extern void __init __deprecated at91_init_serial(struct at91_uart_config *config); struct atmel_uart_data { - short use_dma_tx; /* use transmit DMA? */ - short use_dma_rx; /* use receive DMA? */ - void __iomem *regs; /* virtual base address, if any */ + short use_dma_tx; /* use transmit DMA? */ + short use_dma_rx; /* use receive DMA? */ + void __iomem *regs; /* virt. base address, if any */ + struct serial_rs485 rs485; /* rs485 settings */ }; extern void __init at91_add_device_serial(void); diff --git a/drivers/serial/atmel_serial.c b/drivers/serial/atmel_serial.c index 2c9bf9b..039cd65 100644 --- a/drivers/serial/atmel_serial.c +++ b/drivers/serial/atmel_serial.c @@ -38,6 +38,7 @@ #include <linux/dma-mapping.h> #include <linux/atmel_pdc.h> #include <linux/atmel_serial.h> +#include <linux/uaccess.h> #include <asm/io.h> @@ -59,6 +60,9 @@ #include <linux/serial_core.h> +static void atmel_start_rx(struct uart_port *port); +static void atmel_stop_rx(struct uart_port *port); + #ifdef CONFIG_SERIAL_ATMEL_TTYAT /* Use device name ttyAT, major 204 and minor 154-169. This is necessary if we @@ -93,6 +97,7 @@ #define UART_GET_BRGR(port) __raw_readl((port)->membase + ATMEL_US_BRGR) #define UART_PUT_BRGR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_BRGR) #define UART_PUT_RTOR(port,v) __raw_writel(v, (port)->membase + ATMEL_US_RTOR) +#define UART_PUT_TTGR(port, v) __raw_writel(v, (port)->membase + ATMEL_US_TTGR) /* PDC registers */ #define UART_PUT_PTCR(port,v) __raw_writel(v, (port)->membase + ATMEL_PDC_PTCR) @@ -147,6 +152,9 @@ struct atmel_uart_port { unsigned int irq_status_prev; struct circ_buf rx_ring; + + struct serial_rs485 rs485; /* rs485 settings */ + unsigned int tx_done_mask; }; static struct atmel_uart_port atmel_ports[ATMEL_MAX_UART]; @@ -187,6 +195,81 @@ static bool atmel_use_dma_tx(struct uart_port *port) } #endif +/* Enable or disable the rs485 support */ +void atmel_config_rs485(struct uart_port *port, struct serial_rs485 *rs485conf) +{ + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); + unsigned long flags; + unsigned int mode; + + spin_lock_irqsave(&port->lock, flags); + + mode = UART_GET_MR(port); + + /* Resetting serial mode to RS232 (0x0) */ + mode &= ~ATMEL_US_USMODE; + + atmel_port->rs485 = *rs485conf; + + if (rs485conf->flags & SER_RS485_ENABLED) { + dev_dbg(port->dev, "Setting UART to RS485\n"); + atmel_port->tx_done_mask = ATMEL_US_TXEMPTY; + UART_PUT_TTGR(port, rs485conf->delay_rts_before_send); + mode |= ATMEL_US_USMODE_RS485; + } else { + dev_dbg(port->dev, "Setting UART to RS232\n"); + if (atmel_use_dma_tx(port)) + atmel_port->tx_done_mask = ATMEL_US_ENDTX | + ATMEL_US_TXBUFE; + else + atmel_port->tx_done_mask = ATMEL_US_TXRDY; + } + UART_PUT_MR(port, mode); + + spin_unlock_irqrestore(&port->lock, flags); +} + + +static ssize_t show_rs485(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct platform_device *pdev = to_platform_device(dev); + struct uart_port *port = platform_get_drvdata(pdev); + unsigned int current_mode; + + current_mode = UART_GET_MR(port) & ATMEL_US_USMODE; + return snprintf(buf, PAGE_SIZE, "%u\n", current_mode); +} + +static ssize_t set_rs485(struct device *dev, struct device_attribute *attr, + const char *buf, size_t len) +{ + struct platform_device *pdev = to_platform_device(dev); + struct uart_port *port = platform_get_drvdata(pdev); + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); + struct serial_rs485 rs485conf = atmel_port->rs485; + unsigned int value; + + if (!buf) + return -EINVAL; + + value = !!(simple_strtoul(buf, NULL, 0)); + + if (value) { + rs485conf.flags |= SER_RS485_ENABLED; + /* 0x4 is the normal reset value. */ + rs485conf.delay_rts_before_send = 0x00000004; + } else { + rs485conf.flags &= ~SER_RS485_ENABLED; + } + + atmel_config_rs485(port, &rs485conf); + + return strnlen(buf, PAGE_SIZE); +} + +static DEVICE_ATTR(rs485, 0644, show_rs485, set_rs485); + /* * Return TIOCSER_TEMT when transmitter FIFO and Shift register is empty. */ @@ -202,6 +285,7 @@ static void atmel_set_mctrl(struct uart_port *port, u_int mctrl) { unsigned int control = 0; unsigned int mode; + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); #ifdef CONFIG_ARCH_AT91RM9200 if (cpu_is_at91rm9200()) { @@ -236,6 +320,17 @@ static void atmel_set_mctrl(struct uart_port *port, u_int mctrl) mode |= ATMEL_US_CHMODE_LOC_LOOP; else mode |= ATMEL_US_CHMODE_NORMAL; + + /* Resetting serial mode to RS232 (0x0) */ + mode &= ~ATMEL_US_USMODE; + + if (atmel_port->rs485.flags & SER_RS485_ENABLED) { + dev_dbg(port->dev, "Setting UART to RS485\n"); + UART_PUT_TTGR(port, atmel_port->rs485.delay_rts_before_send); + mode |= ATMEL_US_USMODE_RS485; + } else { + dev_dbg(port->dev, "Setting UART to RS232\n"); + } UART_PUT_MR(port, mode); } @@ -268,12 +363,17 @@ static u_int atmel_get_mctrl(struct uart_port *port) */ static void atmel_stop_tx(struct uart_port *port) { + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); + if (atmel_use_dma_tx(port)) { /* disable PDC transmit */ UART_PUT_PTCR(port, ATMEL_PDC_TXTDIS); - UART_PUT_IDR(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE); - } else - UART_PUT_IDR(port, ATMEL_US_TXRDY); + } + /* Disable interrupts */ + UART_PUT_IDR(port, atmel_port->tx_done_mask); + + if (atmel_port->rs485.flags & SER_RS485_ENABLED) + atmel_start_rx(port); } /* @@ -281,17 +381,39 @@ static void atmel_stop_tx(struct uart_port *port) */ static void atmel_start_tx(struct uart_port *port) { + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); + if (atmel_use_dma_tx(port)) { if (UART_GET_PTSR(port) & ATMEL_PDC_TXTEN) /* The transmitter is already running. Yes, we really need this.*/ return; - UART_PUT_IER(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE); + if (atmel_port->rs485.flags & SER_RS485_ENABLED) + atmel_stop_rx(port); + /* re-enable PDC transmit */ UART_PUT_PTCR(port, ATMEL_PDC_TXTEN); - } else - UART_PUT_IER(port, ATMEL_US_TXRDY); + } + /* Enable interrupts */ + UART_PUT_IER(port, atmel_port->tx_done_mask); +} + +/* + * start receiving - port is in process of being opened. + */ +static void atmel_start_rx(struct uart_port *port) +{ + UART_PUT_CR(port, ATMEL_US_RSTSTA); /* reset status and receiver */ + + if (atmel_use_dma_rx(port)) { + /* enable PDC controller */ + UART_PUT_IER(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT | + port->read_status_mask); + UART_PUT_PTCR(port, ATMEL_PDC_RXTEN); + } else { + UART_PUT_IER(port, ATMEL_US_RXRDY); + } } /* @@ -302,9 +424,11 @@ static void atmel_stop_rx(struct uart_port *port) if (atmel_use_dma_rx(port)) { /* disable PDC receive */ UART_PUT_PTCR(port, ATMEL_PDC_RXTDIS); - UART_PUT_IDR(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT); - } else + UART_PUT_IDR(port, ATMEL_US_ENDRX | ATMEL_US_TIMEOUT | + port->read_status_mask); + } else { UART_PUT_IDR(port, ATMEL_US_RXRDY); + } } /* @@ -428,8 +552,9 @@ static void atmel_rx_chars(struct uart_port *port) static void atmel_tx_chars(struct uart_port *port) { struct circ_buf *xmit = &port->state->xmit; + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); - if (port->x_char && UART_GET_CSR(port) & ATMEL_US_TXRDY) { + if (port->x_char && UART_GET_CSR(port) & atmel_port->tx_done_mask) { UART_PUT_CHAR(port, port->x_char); port->icount.tx++; port->x_char = 0; @@ -437,7 +562,7 @@ static void atmel_tx_chars(struct uart_port *port) if (uart_circ_empty(xmit) || uart_tx_stopped(port)) return; - while (UART_GET_CSR(port) & ATMEL_US_TXRDY) { + while (UART_GET_CSR(port) & atmel_port->tx_done_mask) { UART_PUT_CHAR(port, xmit->buf[xmit->tail]); xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); port->icount.tx++; @@ -449,7 +574,8 @@ static void atmel_tx_chars(struct uart_port *port) uart_write_wakeup(port); if (!uart_circ_empty(xmit)) - UART_PUT_IER(port, ATMEL_US_TXRDY); + /* Enable interrupts */ + UART_PUT_IER(port, atmel_port->tx_done_mask); } /* @@ -501,18 +627,10 @@ atmel_handle_transmit(struct uart_port *port, unsigned int pending) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); - if (atmel_use_dma_tx(port)) { - /* PDC transmit */ - if (pending & (ATMEL_US_ENDTX | ATMEL_US_TXBUFE)) { - UART_PUT_IDR(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE); - tasklet_schedule(&atmel_port->tasklet); - } - } else { - /* Interrupt transmit */ - if (pending & ATMEL_US_TXRDY) { - UART_PUT_IDR(port, ATMEL_US_TXRDY); - tasklet_schedule(&atmel_port->tasklet); - } + if (pending & atmel_port->tx_done_mask) { + /* Either PDC or interrupt transmission */ + UART_PUT_IDR(port, atmel_port->tx_done_mask); + tasklet_schedule(&atmel_port->tasklet); } } @@ -590,9 +708,15 @@ static void atmel_tx_dma(struct uart_port *port) UART_PUT_TPR(port, pdc->dma_addr + xmit->tail); UART_PUT_TCR(port, count); - /* re-enable PDC transmit and interrupts */ + /* re-enable PDC transmit */ UART_PUT_PTCR(port, ATMEL_PDC_TXTEN); - UART_PUT_IER(port, ATMEL_US_ENDTX | ATMEL_US_TXBUFE); + /* Enable interrupts */ + UART_PUT_IER(port, atmel_port->tx_done_mask); + } else { + if (atmel_port->rs485.flags & SER_RS485_ENABLED) { + /* DMA done, stop TX, start RX for RS485 */ + atmel_start_rx(port); + } } if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) @@ -1017,6 +1141,7 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios, { unsigned long flags; unsigned int mode, imr, quot, baud; + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); /* Get current mode register */ mode = UART_GET_MR(port) & ~(ATMEL_US_USCLKS | ATMEL_US_CHRL @@ -1115,6 +1240,17 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios, /* disable receiver and transmitter */ UART_PUT_CR(port, ATMEL_US_TXDIS | ATMEL_US_RXDIS); + /* Resetting serial mode to RS232 (0x0) */ + mode &= ~ATMEL_US_USMODE; + + if (atmel_port->rs485.flags & SER_RS485_ENABLED) { + dev_dbg(port->dev, "Setting UART to RS485\n"); + UART_PUT_TTGR(port, atmel_port->rs485.delay_rts_before_send); + mode |= ATMEL_US_USMODE_RS485; + } else { + dev_dbg(port->dev, "Setting UART to RS232\n"); + } + /* set the parity, stop bits and data size */ UART_PUT_MR(port, mode); @@ -1231,6 +1367,28 @@ static void atmel_poll_put_char(struct uart_port *port, unsigned char ch) } #endif +static int +atmel_ioctl(struct uart_port *port, unsigned int cmd, unsigned long arg) +{ + struct serial_rs485 rs485conf; + + switch (cmd) { + case TIOCSRS485: + if (copy_from_user(&rs485conf, (struct serial_rs485 *) arg, + sizeof(rs485conf))) + return -EFAULT; + + atmel_config_rs485(port, &rs485conf); + break; + + default: + return -ENOIOCTLCMD; + } + return 0; +} + + + static struct uart_ops atmel_pops = { .tx_empty = atmel_tx_empty, .set_mctrl = atmel_set_mctrl, @@ -1250,6 +1408,7 @@ static struct uart_ops atmel_pops = { .config_port = atmel_config_port, .verify_port = atmel_verify_port, .pm = atmel_serial_pm, + .ioctl = atmel_ioctl, #ifdef CONFIG_CONSOLE_POLL .poll_get_char = atmel_poll_get_char, .poll_put_char = atmel_poll_put_char, @@ -1265,13 +1424,12 @@ static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port, struct uart_port *port = &atmel_port->uart; struct atmel_uart_data *data = pdev->dev.platform_data; - port->iotype = UPIO_MEM; - port->flags = UPF_BOOT_AUTOCONF; - port->ops = &atmel_pops; - port->fifosize = 1; - port->line = pdev->id; - port->dev = &pdev->dev; - + port->iotype = UPIO_MEM; + port->flags = UPF_BOOT_AUTOCONF; + port->ops = &atmel_pops; + port->fifosize = 1; + port->line = pdev->id; + port->dev = &pdev->dev; port->mapbase = pdev->resource[0].start; port->irq = pdev->resource[1].start; @@ -1299,8 +1457,16 @@ static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port, atmel_port->use_dma_rx = data->use_dma_rx; atmel_port->use_dma_tx = data->use_dma_tx; - if (atmel_use_dma_tx(port)) + atmel_port->rs485 = data->rs485; + /* Use TXEMPTY for interrupt when rs485 else TXRDY or ENDTX|TXBUFE */ + if (atmel_port->rs485.flags & SER_RS485_ENABLED) + atmel_port->tx_done_mask = ATMEL_US_TXEMPTY; + else if (atmel_use_dma_tx(port)) { port->fifosize = PDC_BUFFER_SIZE; + atmel_port->tx_done_mask = ATMEL_US_ENDTX | ATMEL_US_TXBUFE; + } else { + atmel_port->tx_done_mask = ATMEL_US_TXRDY; + } } /* @@ -1334,6 +1500,7 @@ static void atmel_console_putchar(struct uart_port *port, int ch) static void atmel_console_write(struct console *co, const char *s, u_int count) { struct uart_port *port = &atmel_ports[co->index].uart; + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); unsigned int status, imr; unsigned int pdc_tx; @@ -1341,7 +1508,7 @@ static void atmel_console_write(struct console *co, const char *s, u_int count) * First, save IMR and then disable interrupts */ imr = UART_GET_IMR(port); - UART_PUT_IDR(port, ATMEL_US_RXRDY | ATMEL_US_TXRDY); + UART_PUT_IDR(port, ATMEL_US_RXRDY | atmel_port->tx_done_mask); /* Store PDC transmit status and disable it */ pdc_tx = UART_GET_PTSR(port) & ATMEL_PDC_TXTEN; @@ -1355,7 +1522,7 @@ static void atmel_console_write(struct console *co, const char *s, u_int count) */ do { status = UART_GET_CSR(port); - } while (!(status & ATMEL_US_TXRDY)); + } while (!(status & atmel_port->tx_done_mask)); /* Restore PDC transmit status */ if (pdc_tx) @@ -1587,7 +1754,7 @@ static int __devinit atmel_serial_probe(struct platform_device *pdev) device_init_wakeup(&pdev->dev, 1); platform_set_drvdata(pdev, port); - return 0; + return device_create_file(&(pdev->dev), &dev_attr_rs485); err_add_port: kfree(port->rx_ring.buf); @@ -1619,6 +1786,8 @@ static int __devexit atmel_serial_remove(struct platform_device *pdev) clk_put(atmel_port->clk); + device_remove_file(&(pdev->dev), &dev_attr_rs485); + return ret; } -- 1.6.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Russell King - ARM Linux on 8 Apr 2010 05:10
On Thu, Apr 08, 2010 at 09:58:21AM +0200, Claudio Scordino wrote: > diff --git a/arch/arm/include/asm/ioctls.h b/arch/arm/include/asm/ioctls.h > index a91d8a1..82f2177 100644 > --- a/arch/arm/include/asm/ioctls.h > +++ b/arch/arm/include/asm/ioctls.h > @@ -70,6 +70,8 @@ > #define TIOCGICOUNT 0x545D /* read serial port inline interrupt counts */ > #define FIOQSIZE 0x545E > > +#define TIOCSRS485 0x5461 Why are you only supporting half the interface? #define TIOCGRS485 0x542E #define TIOCSRS485 0x542F is what is in include/asm-generic/ioctls.h - and it would be a good idea to use the same numbering as the generic file rather than creating yet more divergence. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |