Hi Cedric,
On 10/08/2015 05:20 PM, M'boumba Cedric Madianga wrote:
This patch adds support for the STM32 DMA controller.
Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@xxxxxxxxx>
---
drivers/dma/Kconfig | 12 +
drivers/dma/Makefile | 1 +
drivers/dma/stm32-dma.c | 1193 +++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 1206 insertions(+)
create mode 100644 drivers/dma/stm32-dma.c
diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index 5c931d4..4c6b37b 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -431,6 +431,18 @@ config STE_DMA40
help
Support for ST-Ericsson DMA40 controller
+config STM32_DMA
+ tristate "STMicroelectronics STM32 dma support"
s/dma/DMA/ ?
diff --git a/drivers/dma/stm32-dma.c b/drivers/dma/stm32-dma.c
new file mode 100644
index 0000000..9814ca5
--- /dev/null
+++ b/drivers/dma/stm32-dma.c
@@ -0,0 +1,1193 @@
+#define STM32_DMA_LISR 0x0000 /* DMA Low Int Status Reg */
+#define STM32_DMA_HISR 0x0004 /* DMA High Int Status Reg */
+#define STM32_DMA_LIFCR 0x0008 /* DMA Low Int Flag Clear Reg */
+#define STM32_DMA_HIFCR 0x000C /* DMA High Int Flag Clear Reg */
We usually use lower case for numerical values.
+static int stm32_dma_set_xfer_param(struct stm32_dma_chan *chan,
+ enum dma_transfer_direction direction,
+ enum dma_slave_buswidth *buswidth)
+{
+ enum dma_slave_buswidth src_addr_width, dst_addr_width;
+ u32 src_bus_width, dst_bus_width, src_burst_size, dst_burst_size;
+ u32 src_maxburst, dst_maxburst;
+ dma_addr_t src_addr, dst_addr;
+
+ src_addr_width = chan->dma_sconfig.src_addr_width;
+ dst_addr_width = chan->dma_sconfig.dst_addr_width;
+ src_maxburst = chan->dma_sconfig.src_maxburst;
+ dst_maxburst = chan->dma_sconfig.dst_maxburst;
+ src_addr = chan->dma_sconfig.src_addr;
+ dst_addr = chan->dma_sconfig.dst_addr;
+
+ switch (direction) {
+ case DMA_MEM_TO_DEV:
+ dst_bus_width = stm32_get_dma_width(chan, dst_addr_width);
+ if (dst_bus_width < 0)
+ return -EINVAL;
dst_bus_width is a u32, so cannot be negative.
Also, you should propagate de error returned by stm32_get_dma_width().
The comment also applies below:
+ dst_burst_size = stm32_get_dma_burst(chan, dst_maxburst);
+ if (dst_burst_size < 0)
+ return -EINVAL;
+ if (!src_addr_width)
+ src_addr_width = dst_addr_width;
+ src_bus_width = stm32_get_dma_width(chan, src_addr_width);
+ if (src_bus_width < 0)
+ return -EINVAL;
+ src_burst_size = stm32_get_dma_burst(chan, src_maxburst);
+ if (src_burst_size < 0)
+ return -EINVAL;
+
+ chan->chan_reg.dma_scr |= (chan->chan_reg.dma_scr &
+ ~(STM32_DMA_SCR_DIR_MASK | STM32_DMA_SCR_PSIZE_MASK |
+ STM32_DMA_SCR_MSIZE_MASK | STM32_DMA_SCR_PBURST_MASK |
+ STM32_DMA_SCR_MBURST_MASK)) |
+ STM32_DMA_SCR_DIR(STM32_DMA_MEM_TO_DEV) |
+ STM32_DMA_SCR_PSIZE(dst_bus_width) |
+ STM32_DMA_SCR_MSIZE(src_bus_width) |
+ STM32_DMA_SCR_PBURST(dst_burst_size) |
+ STM32_DMA_SCR_MBURST(src_burst_size);
+
+ chan->chan_reg.dma_spar = chan->dma_sconfig.dst_addr;
+ *buswidth = dst_addr_width;
+ return 0;
+
+ case DMA_DEV_TO_MEM:
+ src_bus_width = stm32_get_dma_width(chan, src_addr_width);
+ if (src_bus_width < 0)
+ return -EINVAL;
+ src_burst_size = stm32_get_dma_burst(chan, src_maxburst);
+ if (src_burst_size < 0)
+ return -EINVAL;
+ if (!dst_addr_width)
+ dst_addr_width = src_addr_width;
+ dst_bus_width = stm32_get_dma_width(chan, dst_addr_width);
+ if (dst_bus_width < 0)
+ return -EINVAL;
+ dst_burst_size = stm32_get_dma_burst(chan, dst_maxburst);
+ if (dst_burst_size < 0)
+ return -EINVAL;
+
+ chan->chan_reg.dma_scr |= (chan->chan_reg.dma_scr &
+ ~(STM32_DMA_SCR_DIR_MASK | STM32_DMA_SCR_PSIZE_MASK |
+ STM32_DMA_SCR_MSIZE_MASK | STM32_DMA_SCR_PBURST_MASK |
+ STM32_DMA_SCR_MBURST_MASK)) |
+ STM32_DMA_SCR_DIR(STM32_DMA_DEV_TO_MEM) |
+ STM32_DMA_SCR_PSIZE(src_bus_width) |
+ STM32_DMA_SCR_MSIZE(dst_bus_width) |
+ STM32_DMA_SCR_PBURST(src_burst_size) |
+ STM32_DMA_SCR_MBURST(dst_burst_size);
+ chan->chan_reg.dma_spar = chan->dma_sconfig.src_addr;
+ *buswidth = chan->dma_sconfig.src_addr_width;
+ return 0;
+
+ default:
+ dev_err(chan2dev(chan), "Dma direction is not supported\n");
+ return -EINVAL;
+ }
+
+ return -EINVAL;
+}
Thanks,
Maxime
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