rtc: rp5c01 - Add NVRAM support
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From: Geert Uytterhoeven on 23 Jun 2010 16:00 On Sun, Jun 13, 2010 at 12:12, Geert Uytterhoeven <geert(a)linux-m68k.org> wrote: > The Ricoh RP5C01 RTC contains 26 x 4 bits of NVRAM. > Provide access to it via a sysfs "nvram" attribute file. I also created a small tool to correct NVRAM checksums, interprete the contents, and modify individual NVRAM fields on Amiga 3000/4000. You can find it at git://git.kernel.org/pub/scm/linux/kernel/git/geert/amiga-nvram.git. BTW, does anyone (Arno?) know the meaning of the AMIX-specific bits (32-63)? battmembitsamix.h just says "See Amix documentation for these bit definitions". I also couldn't find anything about it at http://www.amigaunix.com/. Thx! Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert(a)linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- 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: Geert Uytterhoeven on 18 Jul 2010 14:40
On Sun, Jun 13, 2010 at 12:12, Geert Uytterhoeven <geert(a)linux-m68k.org> wrote: > The Ricoh RP5C01 RTC contains 26 x 4 bits of NVRAM. > Provide access to it via a sysfs "nvram" attribute file. > > Signed-off-by: Geert Uytterhoeven <geert(a)linux-m68k.org> Alessandro: Ping? > -- > Question: Is a spinlock in priv the right kind of locking? > Should I use e.g. rtc-device.ops_lock instead? > > diff --git a/drivers/rtc/rtc-rp5c01.c b/drivers/rtc/rtc-rp5c01.c > index a95f733..36eb661 100644 > --- a/drivers/rtc/rtc-rp5c01.c > +++ b/drivers/rtc/rtc-rp5c01.c > @@ -63,6 +63,8 @@ enum { > struct rp5c01_priv { > u32 __iomem *regs; > struct rtc_device *rtc; > + spinlock_t lock; /* against concurrent RTC/NVRAM access */ > + struct bin_attribute nvram_attr; > }; > > static inline unsigned int rp5c01_read(struct rp5c01_priv *priv, > @@ -92,6 +94,7 @@ static int rp5c01_read_time(struct device *dev, struct rtc_time *tm) > { > struct rp5c01_priv *priv = dev_get_drvdata(dev); > > + spin_lock_irq(&priv->lock); > rp5c01_lock(priv); > > tm->tm_sec = rp5c01_read(priv, RP5C01_10_SECOND) * 10 + > @@ -111,6 +114,7 @@ static int rp5c01_read_time(struct device *dev, struct rtc_time *tm) > tm->tm_year += 100; > > rp5c01_unlock(priv); > + spin_unlock_irq(&priv->lock); > > return rtc_valid_tm(tm); > } > @@ -119,6 +123,7 @@ static int rp5c01_set_time(struct device *dev, struct rtc_time *tm) > { > struct rp5c01_priv *priv = dev_get_drvdata(dev); > > + spin_lock_irq(&priv->lock); > rp5c01_lock(priv); > > rp5c01_write(priv, tm->tm_sec / 10, RP5C01_10_SECOND); > @@ -139,6 +144,7 @@ static int rp5c01_set_time(struct device *dev, struct rtc_time *tm) > rp5c01_write(priv, tm->tm_year % 10, RP5C01_1_YEAR); > > rp5c01_unlock(priv); > + spin_unlock_irq(&priv->lock); > return 0; > } > > @@ -147,6 +153,72 @@ static const struct rtc_class_ops rp5c01_rtc_ops = { > .set_time = rp5c01_set_time, > }; > > + > +/* > + * The NVRAM is organized as 2 blocks of 13 nibbles of 4 bits. > + * We provide access to them like AmigaOS does: the high nibble of each 8-bit > + * byte is stored in BLOCK10, the low nibble in BLOCK11. > + */ > + > +static ssize_t rp5c01_nvram_read(struct file *filp, struct kobject *kobj, > + struct bin_attribute *bin_attr, > + char *buf, loff_t pos, size_t size) > +{ > + struct device *dev = container_of(kobj, struct device, kobj); > + struct rp5c01_priv *priv = dev_get_drvdata(dev); > + ssize_t count; > + > + spin_lock_irq(&priv->lock); > + > + for (count = 0; size > 0 && pos < RP5C01_MODE; count++, size--) { > + u8 data; > + > + rp5c01_write(priv, > + RP5C01_MODE_TIMER_EN | RP5C01_MODE_RAM_BLOCK10, > + RP5C01_MODE); > + data = rp5c01_read(priv, pos) << 4; > + rp5c01_write(priv, > + RP5C01_MODE_TIMER_EN | RP5C01_MODE_RAM_BLOCK11, > + RP5C01_MODE); > + data |= rp5c01_read(priv, pos++); > + rp5c01_write(priv, RP5C01_MODE_TIMER_EN | RP5C01_MODE_MODE01, > + RP5C01_MODE); > + *buf++ = data; > + } > + > + spin_unlock_irq(&priv->lock); > + return count; > +} > + > +static ssize_t rp5c01_nvram_write(struct file *filp, struct kobject *kobj, > + struct bin_attribute *bin_attr, > + char *buf, loff_t pos, size_t size) > +{ > + struct device *dev = container_of(kobj, struct device, kobj); > + struct rp5c01_priv *priv = dev_get_drvdata(dev); > + ssize_t count; > + > + spin_lock_irq(&priv->lock); > + > + for (count = 0; size > 0 && pos < RP5C01_MODE; count++, size--) { > + u8 data = *buf++; > + > + rp5c01_write(priv, > + RP5C01_MODE_TIMER_EN | RP5C01_MODE_RAM_BLOCK10, > + RP5C01_MODE); > + rp5c01_write(priv, data >> 4, pos); > + rp5c01_write(priv, > + RP5C01_MODE_TIMER_EN | RP5C01_MODE_RAM_BLOCK11, > + RP5C01_MODE); > + rp5c01_write(priv, data & 0xf, pos++); > + rp5c01_write(priv, RP5C01_MODE_TIMER_EN | RP5C01_MODE_MODE01, > + RP5C01_MODE); > + } > + > + spin_unlock_irq(&priv->lock); > + return count; > +} > + > static int __init rp5c01_rtc_probe(struct platform_device *dev) > { > struct resource *res; > @@ -168,6 +240,15 @@ static int __init rp5c01_rtc_probe(struct platform_device *dev) > goto out_free_priv; > } > > + sysfs_bin_attr_init(&priv->nvram_attr); > + priv->nvram_attr.attr.name = "nvram"; > + priv->nvram_attr.attr.mode = S_IRUGO | S_IWUSR; > + priv->nvram_attr.read = rp5c01_nvram_read; > + priv->nvram_attr.write = rp5c01_nvram_write; > + priv->nvram_attr.size = RP5C01_MODE; > + > + spin_lock_init(&priv->lock); > + > rtc = rtc_device_register("rtc-rp5c01", &dev->dev, &rp5c01_rtc_ops, > THIS_MODULE); > if (IS_ERR(rtc)) { > @@ -177,8 +258,15 @@ static int __init rp5c01_rtc_probe(struct platform_device *dev) > > priv->rtc = rtc; > platform_set_drvdata(dev, priv); > + > + error = sysfs_create_bin_file(&dev->dev.kobj, &priv->nvram_attr); > + if (error) > + goto out_unregister; > + > return 0; > > +out_unregister: > + rtc_device_unregister(rtc); > out_unmap: > iounmap(priv->regs); > out_free_priv: > @@ -190,6 +278,7 @@ static int __exit rp5c01_rtc_remove(struct platform_device *dev) > { > struct rp5c01_priv *priv = platform_get_drvdata(dev); > > + sysfs_remove_bin_file(&dev->dev.kobj, &priv->nvram_attr); > rtc_device_unregister(priv->rtc); > iounmap(priv->regs); > kfree(priv); > -- > 1.7.0.4 Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert(a)linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- 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/ |