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From: Linus Walleij on 11 Jun 2010 11:30
This extends the DMA engine driver for the COH 901 318 used in the
U300 platform with the generic PrimeCell interface.

Signed-off-by: Linus Walleij <linus.walleij(a)stericsson.com>
---
drivers/dma/coh901318.c | 154 +++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 154 insertions(+), 0 deletions(-)

diff --git a/drivers/dma/coh901318.c b/drivers/dma/coh901318.c
index a724e6b..6b21069 100644
--- a/drivers/dma/coh901318.c
+++ b/drivers/dma/coh901318.c
@@ -21,6 +21,7 @@
#include <linux/uaccess.h>
#include <linux/debugfs.h>
#include <mach/coh901318.h>
+#include <linux/amba/dma.h>

#include "coh901318_lli.h"

@@ -72,6 +73,9 @@ struct coh901318_chan {
unsigned long nbr_active_done;
unsigned long busy;

+ u32 amba_addr;
+ u32 amba_ctrl;
+
struct coh901318_base *base;
};

@@ -190,6 +194,9 @@ static inline struct coh901318_chan *to_coh901318_chan(struct dma_chan *chan)
static inline dma_addr_t
cohc_dev_addr(struct coh901318_chan *cohc)
{
+ /* PrimeCell supplied address will take precedence */
+ if (cohc->amba_addr)
+ return cohc->amba_addr;
return cohc->base->platform->chan_conf[cohc->id].dev_addr;
}

@@ -1055,6 +1062,14 @@ coh901318_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,

params = cohc_chan_param(cohc);
config = params->config;
+ /*
+ * Add primecell-specific control on top, make
+ * sure the bits you set per peripheral channel are
+ * cleared in the default config from the platform.
+ */
+ ctrl_chained |= cohc->amba_ctrl;
+ ctrl_last |= cohc->amba_ctrl;
+ ctrl |= cohc->amba_ctrl;

if (direction == DMA_TO_DEVICE) {
u32 tx_flags = COH901318_CX_CTRL_PRDD_SOURCE |
@@ -1113,6 +1128,12 @@ coh901318_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
if (ret)
goto err_lli_fill;

+ /*
+ * Set the default ctrl for the channel to the one from the lli,
+ * things may have changed due to odd buffer alignment etc.
+ */
+ coh901318_set_ctrl(cohc, lli->control);
+
COH_DBG(coh901318_list_print(cohc, lli));

/* Pick a descriptor to handle this transfer */
@@ -1175,6 +1196,130 @@ coh901318_issue_pending(struct dma_chan *chan)
spin_unlock_irqrestore(&cohc->lock, flags);
}

+/*
+ * Here we wrap in the PrimeCell dma interface
+ */
+struct burst_table {
+ int burst_8bit;
+ int burst_16bit;
+ int burst_32bit;
+ u32 reg;
+};
+
+static const struct burst_table burst_sizes[] = {
+ {
+ .burst_8bit = 64,
+ .burst_16bit = 32,
+ .burst_32bit = 16,
+ .reg = COH901318_CX_CTRL_BURST_COUNT_64_BYTES,
+ },
+ {
+ .burst_8bit = 48,
+ .burst_16bit = 24,
+ .burst_32bit = 12,
+ .reg = COH901318_CX_CTRL_BURST_COUNT_48_BYTES,
+ },
+ {
+ .burst_8bit = 32,
+ .burst_16bit = 16,
+ .burst_32bit = 8,
+ .reg = COH901318_CX_CTRL_BURST_COUNT_32_BYTES,
+ },
+ {
+ .burst_8bit = 16,
+ .burst_16bit = 8,
+ .burst_32bit = 4,
+ .reg = COH901318_CX_CTRL_BURST_COUNT_16_BYTES,
+ },
+ {
+ .burst_8bit = 8,
+ .burst_16bit = 4,
+ .burst_32bit = 2,
+ .reg = COH901318_CX_CTRL_BURST_COUNT_8_BYTES,
+ },
+ {
+ .burst_8bit = 4,
+ .burst_16bit = 2,
+ .burst_32bit = 1,
+ .reg = COH901318_CX_CTRL_BURST_COUNT_4_BYTES,
+ },
+ {
+ .burst_8bit = 2,
+ .burst_16bit = 1,
+ .burst_32bit = 0,
+ .reg = COH901318_CX_CTRL_BURST_COUNT_2_BYTES,
+ },
+ {
+ .burst_8bit = 1,
+ .burst_16bit = 0,
+ .burst_32bit = 0,
+ .reg = COH901318_CX_CTRL_BURST_COUNT_1_BYTE,
+ },
+};
+
+static void coh901318_dma_set_ambaconfig(struct dma_chan *chan,
+ struct amba_dma_channel_config *config)
+{
+ struct coh901318_chan *cohc = to_coh901318_chan(chan);
+ int maxburst = config->maxburst;
+ u32 amba_ctrl = 0;
+ int i = 0;
+
+ dev_dbg(COHC_2_DEV(cohc), "configure channel for %d byte transfers\n",
+ config->addr_width);
+ switch (config->addr_width) {
+ case 1:
+ amba_ctrl |=
+ COH901318_CX_CTRL_SRC_BUS_SIZE_8_BITS |
+ COH901318_CX_CTRL_DST_BUS_SIZE_8_BITS;
+
+ while (i < ARRAY_SIZE(burst_sizes)) {
+ if (burst_sizes[i].burst_8bit <= maxburst)
+ break;
+ i++;
+ }
+
+ break;
+ case 2:
+ amba_ctrl |=
+ COH901318_CX_CTRL_SRC_BUS_SIZE_16_BITS |
+ COH901318_CX_CTRL_DST_BUS_SIZE_16_BITS;
+
+ while (i < ARRAY_SIZE(burst_sizes)) {
+ if (burst_sizes[i].burst_16bit <= maxburst)
+ break;
+ i++;
+ }
+
+ break;
+ case 4:
+ /* Direction doesn't matter here, it's 32/32 bits */
+ amba_ctrl |=
+ COH901318_CX_CTRL_SRC_BUS_SIZE_32_BITS |
+ COH901318_CX_CTRL_DST_BUS_SIZE_32_BITS;
+
+ while (i < ARRAY_SIZE(burst_sizes)) {
+ if (burst_sizes[i].burst_32bit <= maxburst)
+ break;
+ i++;
+ }
+
+ break;
+ default:
+ dev_err(COHC_2_DEV(cohc),
+ "bad ambaconfig: alien address width\n");
+ return;
+ }
+
+ amba_ctrl |= burst_sizes[i].reg;
+ dev_dbg(COHC_2_DEV(cohc),
+ "selected burst size %d bytes for address width %d bytes, maxburst %d\n",
+ burst_sizes[i].burst_8bit, config->addr_width, maxburst);
+
+ cohc->amba_addr = config->addr;
+ cohc->amba_ctrl = amba_ctrl;
+}
+
static int
coh901318_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
unsigned long arg)
@@ -1184,6 +1329,14 @@ coh901318_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
struct coh901318_desc *cohd;
void __iomem *virtbase = cohc->base->virtbase;

+ if (cmd == DMA_CONFIG_AMBA) {
+ struct amba_dma_channel_config *config =
+ (struct amba_dma_channel_config *) arg;
+
+ coh901318_dma_set_ambaconfig(chan, config);
+ return 0;
+ }
+
if (cmd == DMA_PAUSE) {
coh901318_pause(chan);
return 0;
@@ -1240,6 +1393,7 @@ coh901318_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,

return 0;
}
+
void coh901318_base_init(struct dma_device *dma, const int *pick_chans,
struct coh901318_base *base)
{
--
1.6.3.3

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Prev: linux-next-20100608 will /bin/sh: scripts/basic/fixdep: Permission denied
Next: [PATCH 07/13] ARM: add PrimeCell generic DMA to PL022 v8