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Subject[PATCH 3/4] dmaengine/ste_dma40: allow memory buswidth/burst to be configured
Date
From: Rabin Vincent <rabin.vincent@stericsson.com>

Currently the runtime config implementation forces the memory side
parameters to be the same as the peripheral side. Allow these to be
different, and check for misconfiguration.

Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
Reviewed-by: Ulf HANSSON <ulf.hansson@stericsson.com>
Tested-by: Stefan Nilsson <stefan.xk.nilsson@stericsson.com>
Reviewed-by: Per Forlin <per.forlin@stericsson.com>
Reviewed-by: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Cc: Robert Marklund <robert.marklund@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
drivers/dma/ste_dma40.c | 168 ++++++++++++++++++++++++++++------------------
1 files changed, 102 insertions(+), 66 deletions(-)

diff --git a/drivers/dma/ste_dma40.c b/drivers/dma/ste_dma40.c
index 35b078d..096167f 100644
--- a/drivers/dma/ste_dma40.c
+++ b/drivers/dma/ste_dma40.c
@@ -2181,17 +2181,78 @@ static void d40_issue_pending(struct dma_chan *chan)
spin_unlock_irqrestore(&d40c->lock, flags);
}

+static int
+dma40_config_to_halfchannel(struct d40_chan *d40c,
+ struct stedma40_half_channel_info *info,
+ enum dma_slave_buswidth width,
+ u32 maxburst)
+{
+ enum stedma40_periph_data_width addr_width;
+ int psize;
+
+ switch (width) {
+ case DMA_SLAVE_BUSWIDTH_1_BYTE:
+ addr_width = STEDMA40_BYTE_WIDTH;
+ break;
+ case DMA_SLAVE_BUSWIDTH_2_BYTES:
+ addr_width = STEDMA40_HALFWORD_WIDTH;
+ break;
+ case DMA_SLAVE_BUSWIDTH_4_BYTES:
+ addr_width = STEDMA40_WORD_WIDTH;
+ break;
+ case DMA_SLAVE_BUSWIDTH_8_BYTES:
+ addr_width = STEDMA40_DOUBLEWORD_WIDTH;
+ break;
+ default:
+ dev_err(d40c->base->dev,
+ "illegal peripheral address width "
+ "requested (%d)\n",
+ width);
+ return -EINVAL;
+ }
+
+ if (chan_is_logical(d40c)) {
+ if (maxburst >= 16)
+ psize = STEDMA40_PSIZE_LOG_16;
+ else if (maxburst >= 8)
+ psize = STEDMA40_PSIZE_LOG_8;
+ else if (maxburst >= 4)
+ psize = STEDMA40_PSIZE_LOG_4;
+ else
+ psize = STEDMA40_PSIZE_LOG_1;
+ } else {
+ if (maxburst >= 16)
+ psize = STEDMA40_PSIZE_PHY_16;
+ else if (maxburst >= 8)
+ psize = STEDMA40_PSIZE_PHY_8;
+ else if (maxburst >= 4)
+ psize = STEDMA40_PSIZE_PHY_4;
+ else
+ psize = STEDMA40_PSIZE_PHY_1;
+ }
+
+ info->data_width = addr_width;
+ info->psize = psize;
+ info->flow_ctrl = STEDMA40_NO_FLOW_CTRL;
+
+ return 0;
+}
+
/* Runtime reconfiguration extension */
-static void d40_set_runtime_config(struct dma_chan *chan,
- struct dma_slave_config *config)
+static int d40_set_runtime_config(struct dma_chan *chan,
+ struct dma_slave_config *config)
{
struct d40_chan *d40c = container_of(chan, struct d40_chan, chan);
struct stedma40_chan_cfg *cfg = &d40c->dma_cfg;
- enum dma_slave_buswidth config_addr_width;
+ enum dma_slave_buswidth src_addr_width, dst_addr_width;
dma_addr_t config_addr;
- u32 config_maxburst;
- enum stedma40_periph_data_width addr_width;
- int psize;
+ u32 src_maxburst, dst_maxburst;
+ int ret;
+
+ src_addr_width = config->src_addr_width;
+ src_maxburst = config->src_maxburst;
+ dst_addr_width = config->dst_addr_width;
+ dst_maxburst = config->dst_maxburst;

if (config->direction == DMA_FROM_DEVICE) {
dma_addr_t dev_addr_rx =
@@ -2210,8 +2271,11 @@ static void d40_set_runtime_config(struct dma_chan *chan,
cfg->dir);
cfg->dir = STEDMA40_PERIPH_TO_MEM;

- config_addr_width = config->src_addr_width;
- config_maxburst = config->src_maxburst;
+ /* Configure the memory side */
+ if (dst_addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED)
+ dst_addr_width = src_addr_width;
+ if (dst_maxburst == 0)
+ dst_maxburst = src_maxburst;

} else if (config->direction == DMA_TO_DEVICE) {
dma_addr_t dev_addr_tx =
@@ -2230,68 +2294,39 @@ static void d40_set_runtime_config(struct dma_chan *chan,
cfg->dir);
cfg->dir = STEDMA40_MEM_TO_PERIPH;

- config_addr_width = config->dst_addr_width;
- config_maxburst = config->dst_maxburst;
-
+ /* Configure the memory side */
+ if (src_addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED)
+ src_addr_width = dst_addr_width;
+ if (src_maxburst == 0)
+ src_maxburst = dst_maxburst;
} else {
dev_err(d40c->base->dev,
"unrecognized channel direction %d\n",
config->direction);
- return;
+ return -EINVAL;
}

- switch (config_addr_width) {
- case DMA_SLAVE_BUSWIDTH_1_BYTE:
- addr_width = STEDMA40_BYTE_WIDTH;
- break;
- case DMA_SLAVE_BUSWIDTH_2_BYTES:
- addr_width = STEDMA40_HALFWORD_WIDTH;
- break;
- case DMA_SLAVE_BUSWIDTH_4_BYTES:
- addr_width = STEDMA40_WORD_WIDTH;
- break;
- case DMA_SLAVE_BUSWIDTH_8_BYTES:
- addr_width = STEDMA40_DOUBLEWORD_WIDTH;
- break;
- default:
+ if (src_maxburst * src_addr_width != dst_maxburst * dst_addr_width) {
dev_err(d40c->base->dev,
- "illegal peripheral address width "
- "requested (%d)\n",
- config->src_addr_width);
- return;
+ "src/dst width/maxburst mismatch: %d*%d != %d*%d\n",
+ src_maxburst,
+ src_addr_width,
+ dst_maxburst,
+ dst_addr_width);
+ return -EINVAL;
}

- if (chan_is_logical(d40c)) {
- if (config_maxburst >= 16)
- psize = STEDMA40_PSIZE_LOG_16;
- else if (config_maxburst >= 8)
- psize = STEDMA40_PSIZE_LOG_8;
- else if (config_maxburst >= 4)
- psize = STEDMA40_PSIZE_LOG_4;
- else
- psize = STEDMA40_PSIZE_LOG_1;
- } else {
- if (config_maxburst >= 16)
- psize = STEDMA40_PSIZE_PHY_16;
- else if (config_maxburst >= 8)
- psize = STEDMA40_PSIZE_PHY_8;
- else if (config_maxburst >= 4)
- psize = STEDMA40_PSIZE_PHY_4;
- else if (config_maxburst >= 2)
- psize = STEDMA40_PSIZE_PHY_2;
- else
- psize = STEDMA40_PSIZE_PHY_1;
- }
+ ret = dma40_config_to_halfchannel(d40c, &cfg->src_info,
+ src_addr_width,
+ src_maxburst);
+ if (ret)
+ return ret;

- /* Set up all the endpoint configs */
- cfg->src_info.data_width = addr_width;
- cfg->src_info.psize = psize;
- cfg->src_info.big_endian = false;
- cfg->src_info.flow_ctrl = STEDMA40_NO_FLOW_CTRL;
- cfg->dst_info.data_width = addr_width;
- cfg->dst_info.psize = psize;
- cfg->dst_info.big_endian = false;
- cfg->dst_info.flow_ctrl = STEDMA40_NO_FLOW_CTRL;
+ ret = dma40_config_to_halfchannel(d40c, &cfg->dst_info,
+ dst_addr_width,
+ dst_maxburst);
+ if (ret)
+ return ret;

/* Fill in register values */
if (chan_is_logical(d40c))
@@ -2304,12 +2339,14 @@ static void d40_set_runtime_config(struct dma_chan *chan,
d40c->runtime_addr = config_addr;
d40c->runtime_direction = config->direction;
dev_dbg(d40c->base->dev,
- "configured channel %s for %s, data width %d, "
- "maxburst %d bytes, LE, no flow control\n",
+ "configured channel %s for %s, data width %d/%d, "
+ "maxburst %d/%d elements, LE, no flow control\n",
dma_chan_name(chan),
(config->direction == DMA_FROM_DEVICE) ? "RX" : "TX",
- config_addr_width,
- config_maxburst);
+ src_addr_width, dst_addr_width,
+ src_maxburst, dst_maxburst);
+
+ return 0;
}

static int d40_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
@@ -2330,9 +2367,8 @@ static int d40_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
case DMA_RESUME:
return d40_resume(d40c);
case DMA_SLAVE_CONFIG:
- d40_set_runtime_config(chan,
+ return d40_set_runtime_config(chan,
(struct dma_slave_config *) arg);
- return 0;
default:
break;
}
--
1.7.3.2


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