[RESEND PATCH v1 4/6] i2c: i2c-stm32: Add generic DMA API

[Pierre-Yves MORDRET]

This patch adds a generic DMA API to implement DMA support for i2c-stm32fx
drivers

Signed-off-by: M'boumba Cedric Madianga 
Signed-off-by: Pierre-Yves MORDRET 
---
  Version history:
v1:
   * Initial
---
---
 drivers/i2c/busses/i2c-stm32.c | 153 +
 drivers/i2c/busses/i2c-stm32.h |  37 ++
 2 files changed, 190 insertions(+)
 create mode 100644 drivers/i2c/busses/i2c-stm32.c

diff --git a/drivers/i2c/busses/i2c-stm32.c b/drivers/i2c/busses/i2c-stm32.c
new file mode 100644
index 000..d75fbcb
--- /dev/null
+++ b/drivers/i2c/busses/i2c-stm32.c
@@ -0,0 +1,153 @@
+/*
+ * i2c-stm32.c
+ *
+ * Copyright (C) M'boumba Cedric Madianga 2017
+ * Author: M'boumba Cedric Madianga 
+ *
+ * License terms:  GNU General Public License (GPL), version 2
+ */
+
+#include "i2c-stm32.h"
+
+/* Functions for DMA support */
+struct stm32_i2c_dma *stm32_i2c_dma_request(struct device *dev,
+   dma_addr_t phy_addr,
+   u32 txdr_offset,
+   u32 rxdr_offset)
+{
+   struct stm32_i2c_dma *dma;
+   struct dma_slave_config dma_sconfig;
+   int ret;
+
+   dma = devm_kzalloc(dev, sizeof(*dma), GFP_KERNEL);
+   if (!dma)
+   return NULL;
+
+   /* Request and configure I2C TX dma channel */
+   dma->chan_tx = dma_request_slave_channel(dev, "tx");
+   if (!dma->chan_tx) {
+   dev_dbg(dev, "can't request DMA tx channel\n");
+   ret = -EINVAL;
+   goto fail_al;
+   }
+
+   memset(_sconfig, 0, sizeof(dma_sconfig));
+   dma_sconfig.dst_addr = phy_addr + txdr_offset;
+   dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+   dma_sconfig.dst_maxburst = 1;
+   dma_sconfig.direction = DMA_MEM_TO_DEV;
+   ret = dmaengine_slave_config(dma->chan_tx, _sconfig);
+   if (ret < 0) {
+   dev_err(dev, "can't configure tx channel\n");
+   goto fail_tx;
+   }
+
+   /* Request and configure I2C RX dma channel */
+   dma->chan_rx = dma_request_slave_channel(dev, "rx");
+   if (!dma->chan_rx) {
+   dev_err(dev, "can't request DMA rx channel\n");
+   ret = -EINVAL;
+   goto fail_tx;
+   }
+
+   memset(_sconfig, 0, sizeof(dma_sconfig));
+   dma_sconfig.src_addr = phy_addr + rxdr_offset;
+   dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+   dma_sconfig.src_maxburst = 1;
+   dma_sconfig.direction = DMA_DEV_TO_MEM;
+   ret = dmaengine_slave_config(dma->chan_rx, _sconfig);
+   if (ret < 0) {
+   dev_err(dev, "can't configure rx channel\n");
+   goto fail_rx;
+   }
+
+   init_completion(>dma_complete);
+
+   dev_info(dev, "using %s (tx) and %s (rx) for DMA transfers\n",
+dma_chan_name(dma->chan_tx), dma_chan_name(dma->chan_rx));
+
+   return dma;
+
+fail_rx:
+   dma_release_channel(dma->chan_rx);
+fail_tx:
+   dma_release_channel(dma->chan_tx);
+fail_al:
+   devm_kfree(dev, dma);
+   dev_info(dev, "can't use DMA\n");
+
+   return NULL;
+}
+
+void stm32_i2c_dma_free(struct stm32_i2c_dma *dma)
+{
+   dma->dma_buf = 0;
+   dma->dma_len = 0;
+
+   dma_release_channel(dma->chan_tx);
+   dma->chan_tx = NULL;
+
+   dma_release_channel(dma->chan_rx);
+   dma->chan_rx = NULL;
+
+   dma->chan_using = NULL;
+}
+
+int stm32_i2c_prep_dma_xfer(struct device *dev, struct stm32_i2c_dma *dma,
+   bool rd_wr, u32 len, u8 *buf,
+   dma_async_tx_callback callback,
+   void *dma_async_param)
+{
+   struct dma_async_tx_descriptor *txdesc;
+   struct device *chan_dev;
+   int ret;
+
+   if (rd_wr) {
+   dma->chan_using = dma->chan_rx;
+   dma->dma_transfer_dir = DMA_DEV_TO_MEM;
+   dma->dma_data_dir = DMA_FROM_DEVICE;
+   } else {
+   dma->chan_using = dma->chan_tx;
+   dma->dma_transfer_dir = DMA_MEM_TO_DEV;
+   dma->dma_data_dir = DMA_TO_DEVICE;
+   }
+
+   dma->dma_len = len;
+   chan_dev = dma->chan_using->device->dev;
+
+   dma->dma_buf = dma_map_single(chan_dev, buf, dma->dma_len,
+ dma->dma_data_dir);
+   if (dma_mapping_error(chan_dev, dma->dma_buf)) {
+   dev_err(dev, "DMA mapping failed\n");
+   return -EINVAL;
+   }
+
+   txdesc = dmaengine_prep_slave_single(dma->chan_using, dma->dma_buf,
+dma->dma_len,
+dma->dma_transfer_dir,
+DMA_PREP_INTERRUPT);
+   if (!txdesc) {
+   dev_err(dev, "Not able to get desc 

[RESEND PATCH v1 4/6] i2c: i2c-stm32: Add generic DMA API

[Pierre-Yves MORDRET]

This patch adds a generic DMA API to implement DMA support for i2c-stm32fx
drivers

Signed-off-by: M'boumba Cedric Madianga 
Signed-off-by: Pierre-Yves MORDRET 
---
  Version history:
v1:
   * Initial
---
---
 drivers/i2c/busses/i2c-stm32.c | 153 +
 drivers/i2c/busses/i2c-stm32.h |  37 ++
 2 files changed, 190 insertions(+)
 create mode 100644 drivers/i2c/busses/i2c-stm32.c

diff --git a/drivers/i2c/busses/i2c-stm32.c b/drivers/i2c/busses/i2c-stm32.c
new file mode 100644
index 000..d75fbcb
--- /dev/null
+++ b/drivers/i2c/busses/i2c-stm32.c
@@ -0,0 +1,153 @@
+/*
+ * i2c-stm32.c
+ *
+ * Copyright (C) M'boumba Cedric Madianga 2017
+ * Author: M'boumba Cedric Madianga 
+ *
+ * License terms:  GNU General Public License (GPL), version 2
+ */
+
+#include "i2c-stm32.h"
+
+/* Functions for DMA support */
+struct stm32_i2c_dma *stm32_i2c_dma_request(struct device *dev,
+   dma_addr_t phy_addr,
+   u32 txdr_offset,
+   u32 rxdr_offset)
+{
+   struct stm32_i2c_dma *dma;
+   struct dma_slave_config dma_sconfig;
+   int ret;
+
+   dma = devm_kzalloc(dev, sizeof(*dma), GFP_KERNEL);
+   if (!dma)
+   return NULL;
+
+   /* Request and configure I2C TX dma channel */
+   dma->chan_tx = dma_request_slave_channel(dev, "tx");
+   if (!dma->chan_tx) {
+   dev_dbg(dev, "can't request DMA tx channel\n");
+   ret = -EINVAL;
+   goto fail_al;
+   }
+
+   memset(_sconfig, 0, sizeof(dma_sconfig));
+   dma_sconfig.dst_addr = phy_addr + txdr_offset;
+   dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+   dma_sconfig.dst_maxburst = 1;
+   dma_sconfig.direction = DMA_MEM_TO_DEV;
+   ret = dmaengine_slave_config(dma->chan_tx, _sconfig);
+   if (ret < 0) {
+   dev_err(dev, "can't configure tx channel\n");
+   goto fail_tx;
+   }
+
+   /* Request and configure I2C RX dma channel */
+   dma->chan_rx = dma_request_slave_channel(dev, "rx");
+   if (!dma->chan_rx) {
+   dev_err(dev, "can't request DMA rx channel\n");
+   ret = -EINVAL;
+   goto fail_tx;
+   }
+
+   memset(_sconfig, 0, sizeof(dma_sconfig));
+   dma_sconfig.src_addr = phy_addr + rxdr_offset;
+   dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+   dma_sconfig.src_maxburst = 1;
+   dma_sconfig.direction = DMA_DEV_TO_MEM;
+   ret = dmaengine_slave_config(dma->chan_rx, _sconfig);
+   if (ret < 0) {
+   dev_err(dev, "can't configure rx channel\n");
+   goto fail_rx;
+   }
+
+   init_completion(>dma_complete);
+
+   dev_info(dev, "using %s (tx) and %s (rx) for DMA transfers\n",
+dma_chan_name(dma->chan_tx), dma_chan_name(dma->chan_rx));
+
+   return dma;
+
+fail_rx:
+   dma_release_channel(dma->chan_rx);
+fail_tx:
+   dma_release_channel(dma->chan_tx);
+fail_al:
+   devm_kfree(dev, dma);
+   dev_info(dev, "can't use DMA\n");
+
+   return NULL;
+}
+
+void stm32_i2c_dma_free(struct stm32_i2c_dma *dma)
+{
+   dma->dma_buf = 0;
+   dma->dma_len = 0;
+
+   dma_release_channel(dma->chan_tx);
+   dma->chan_tx = NULL;
+
+   dma_release_channel(dma->chan_rx);
+   dma->chan_rx = NULL;
+
+   dma->chan_using = NULL;
+}
+
+int stm32_i2c_prep_dma_xfer(struct device *dev, struct stm32_i2c_dma *dma,
+   bool rd_wr, u32 len, u8 *buf,
+   dma_async_tx_callback callback,
+   void *dma_async_param)
+{
+   struct dma_async_tx_descriptor *txdesc;
+   struct device *chan_dev;
+   int ret;
+
+   if (rd_wr) {
+   dma->chan_using = dma->chan_rx;
+   dma->dma_transfer_dir = DMA_DEV_TO_MEM;
+   dma->dma_data_dir = DMA_FROM_DEVICE;
+   } else {
+   dma->chan_using = dma->chan_tx;
+   dma->dma_transfer_dir = DMA_MEM_TO_DEV;
+   dma->dma_data_dir = DMA_TO_DEVICE;
+   }
+
+   dma->dma_len = len;
+   chan_dev = dma->chan_using->device->dev;
+
+   dma->dma_buf = dma_map_single(chan_dev, buf, dma->dma_len,
+ dma->dma_data_dir);
+   if (dma_mapping_error(chan_dev, dma->dma_buf)) {
+   dev_err(dev, "DMA mapping failed\n");
+   return -EINVAL;
+   }
+
+   txdesc = dmaengine_prep_slave_single(dma->chan_using, dma->dma_buf,
+dma->dma_len,
+dma->dma_transfer_dir,
+DMA_PREP_INTERRUPT);
+   if (!txdesc) {
+   dev_err(dev, "Not able to get desc for DMA xfer\n");
+   ret = -EINVAL;
+   goto err;
+  

[RESEND PATCH v1 4/6] i2c: i2c-stm32: Add generic DMA API

[Pierre-Yves MORDRET]

This patch adds a generic DMA API to implement DMA support for i2c-stm32fx
drivers

Signed-off-by: M'boumba Cedric Madianga 
Signed-off-by: Pierre-Yves MORDRET 
---
  Version history:
v1:
   * Initial
---
---
 drivers/i2c/busses/i2c-stm32.c | 153 +
 drivers/i2c/busses/i2c-stm32.h |  37 ++
 2 files changed, 190 insertions(+)
 create mode 100644 drivers/i2c/busses/i2c-stm32.c

diff --git a/drivers/i2c/busses/i2c-stm32.c b/drivers/i2c/busses/i2c-stm32.c
new file mode 100644
index 000..d75fbcb
--- /dev/null
+++ b/drivers/i2c/busses/i2c-stm32.c
@@ -0,0 +1,153 @@
+/*
+ * i2c-stm32.c
+ *
+ * Copyright (C) M'boumba Cedric Madianga 2017
+ * Author: M'boumba Cedric Madianga 
+ *
+ * License terms:  GNU General Public License (GPL), version 2
+ */
+
+#include "i2c-stm32.h"
+
+/* Functions for DMA support */
+struct stm32_i2c_dma *stm32_i2c_dma_request(struct device *dev,
+   dma_addr_t phy_addr,
+   u32 txdr_offset,
+   u32 rxdr_offset)
+{
+   struct stm32_i2c_dma *dma;
+   struct dma_slave_config dma_sconfig;
+   int ret;
+
+   dma = devm_kzalloc(dev, sizeof(*dma), GFP_KERNEL);
+   if (!dma)
+   return NULL;
+
+   /* Request and configure I2C TX dma channel */
+   dma->chan_tx = dma_request_slave_channel(dev, "tx");
+   if (!dma->chan_tx) {
+   dev_dbg(dev, "can't request DMA tx channel\n");
+   ret = -EINVAL;
+   goto fail_al;
+   }
+
+   memset(_sconfig, 0, sizeof(dma_sconfig));
+   dma_sconfig.dst_addr = phy_addr + txdr_offset;
+   dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+   dma_sconfig.dst_maxburst = 1;
+   dma_sconfig.direction = DMA_MEM_TO_DEV;
+   ret = dmaengine_slave_config(dma->chan_tx, _sconfig);
+   if (ret < 0) {
+   dev_err(dev, "can't configure tx channel\n");
+   goto fail_tx;
+   }
+
+   /* Request and configure I2C RX dma channel */
+   dma->chan_rx = dma_request_slave_channel(dev, "rx");
+   if (!dma->chan_rx) {
+   dev_err(dev, "can't request DMA rx channel\n");
+   ret = -EINVAL;
+   goto fail_tx;
+   }
+
+   memset(_sconfig, 0, sizeof(dma_sconfig));
+   dma_sconfig.src_addr = phy_addr + rxdr_offset;
+   dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+   dma_sconfig.src_maxburst = 1;
+   dma_sconfig.direction = DMA_DEV_TO_MEM;
+   ret = dmaengine_slave_config(dma->chan_rx, _sconfig);
+   if (ret < 0) {
+   dev_err(dev, "can't configure rx channel\n");
+   goto fail_rx;
+   }
+
+   init_completion(>dma_complete);
+
+   dev_info(dev, "using %s (tx) and %s (rx) for DMA transfers\n",
+dma_chan_name(dma->chan_tx), dma_chan_name(dma->chan_rx));
+
+   return dma;
+
+fail_rx:
+   dma_release_channel(dma->chan_rx);
+fail_tx:
+   dma_release_channel(dma->chan_tx);
+fail_al:
+   devm_kfree(dev, dma);
+   dev_info(dev, "can't use DMA\n");
+
+   return NULL;
+}
+
+void stm32_i2c_dma_free(struct stm32_i2c_dma *dma)
+{
+   dma->dma_buf = 0;
+   dma->dma_len = 0;
+
+   dma_release_channel(dma->chan_tx);
+   dma->chan_tx = NULL;
+
+   dma_release_channel(dma->chan_rx);
+   dma->chan_rx = NULL;
+
+   dma->chan_using = NULL;
+}
+
+int stm32_i2c_prep_dma_xfer(struct device *dev, struct stm32_i2c_dma *dma,
+   bool rd_wr, u32 len, u8 *buf,
+   dma_async_tx_callback callback,
+   void *dma_async_param)
+{
+   struct dma_async_tx_descriptor *txdesc;
+   struct device *chan_dev;
+   int ret;
+
+   if (rd_wr) {
+   dma->chan_using = dma->chan_rx;
+   dma->dma_transfer_dir = DMA_DEV_TO_MEM;
+   dma->dma_data_dir = DMA_FROM_DEVICE;
+   } else {
+   dma->chan_using = dma->chan_tx;
+   dma->dma_transfer_dir = DMA_MEM_TO_DEV;
+   dma->dma_data_dir = DMA_TO_DEVICE;
+   }
+
+   dma->dma_len = len;
+   chan_dev = dma->chan_using->device->dev;
+
+   dma->dma_buf = dma_map_single(chan_dev, buf, dma->dma_len,
+ dma->dma_data_dir);
+   if (dma_mapping_error(chan_dev, dma->dma_buf)) {
+   dev_err(dev, "DMA mapping failed\n");
+   return -EINVAL;
+   }
+
+   txdesc = dmaengine_prep_slave_single(dma->chan_using, dma->dma_buf,
+dma->dma_len,
+dma->dma_transfer_dir,
+DMA_PREP_INTERRUPT);
+   if (!txdesc) {
+   dev_err(dev, "Not able to get desc 

[RESEND PATCH v1 4/6] i2c: i2c-stm32: Add generic DMA API

[Pierre-Yves MORDRET]

This patch adds a generic DMA API to implement DMA support for i2c-stm32fx
drivers

Signed-off-by: M'boumba Cedric Madianga 
Signed-off-by: Pierre-Yves MORDRET 
---
  Version history:
v1:
   * Initial
---
---
 drivers/i2c/busses/i2c-stm32.c | 153 +
 drivers/i2c/busses/i2c-stm32.h |  37 ++
 2 files changed, 190 insertions(+)
 create mode 100644 drivers/i2c/busses/i2c-stm32.c

diff --git a/drivers/i2c/busses/i2c-stm32.c b/drivers/i2c/busses/i2c-stm32.c
new file mode 100644
index 000..d75fbcb
--- /dev/null
+++ b/drivers/i2c/busses/i2c-stm32.c
@@ -0,0 +1,153 @@
+/*
+ * i2c-stm32.c
+ *
+ * Copyright (C) M'boumba Cedric Madianga 2017
+ * Author: M'boumba Cedric Madianga 
+ *
+ * License terms:  GNU General Public License (GPL), version 2
+ */
+
+#include "i2c-stm32.h"
+
+/* Functions for DMA support */
+struct stm32_i2c_dma *stm32_i2c_dma_request(struct device *dev,
+   dma_addr_t phy_addr,
+   u32 txdr_offset,
+   u32 rxdr_offset)
+{
+   struct stm32_i2c_dma *dma;
+   struct dma_slave_config dma_sconfig;
+   int ret;
+
+   dma = devm_kzalloc(dev, sizeof(*dma), GFP_KERNEL);
+   if (!dma)
+   return NULL;
+
+   /* Request and configure I2C TX dma channel */
+   dma->chan_tx = dma_request_slave_channel(dev, "tx");
+   if (!dma->chan_tx) {
+   dev_dbg(dev, "can't request DMA tx channel\n");
+   ret = -EINVAL;
+   goto fail_al;
+   }
+
+   memset(_sconfig, 0, sizeof(dma_sconfig));
+   dma_sconfig.dst_addr = phy_addr + txdr_offset;
+   dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+   dma_sconfig.dst_maxburst = 1;
+   dma_sconfig.direction = DMA_MEM_TO_DEV;
+   ret = dmaengine_slave_config(dma->chan_tx, _sconfig);
+   if (ret < 0) {
+   dev_err(dev, "can't configure tx channel\n");
+   goto fail_tx;
+   }
+
+   /* Request and configure I2C RX dma channel */
+   dma->chan_rx = dma_request_slave_channel(dev, "rx");
+   if (!dma->chan_rx) {
+   dev_err(dev, "can't request DMA rx channel\n");
+   ret = -EINVAL;
+   goto fail_tx;
+   }
+
+   memset(_sconfig, 0, sizeof(dma_sconfig));
+   dma_sconfig.src_addr = phy_addr + rxdr_offset;
+   dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+   dma_sconfig.src_maxburst = 1;
+   dma_sconfig.direction = DMA_DEV_TO_MEM;
+   ret = dmaengine_slave_config(dma->chan_rx, _sconfig);
+   if (ret < 0) {
+   dev_err(dev, "can't configure rx channel\n");
+   goto fail_rx;
+   }
+
+   init_completion(>dma_complete);
+
+   dev_info(dev, "using %s (tx) and %s (rx) for DMA transfers\n",
+dma_chan_name(dma->chan_tx), dma_chan_name(dma->chan_rx));
+
+   return dma;
+
+fail_rx:
+   dma_release_channel(dma->chan_rx);
+fail_tx:
+   dma_release_channel(dma->chan_tx);
+fail_al:
+   devm_kfree(dev, dma);
+   dev_info(dev, "can't use DMA\n");
+
+   return NULL;
+}
+
+void stm32_i2c_dma_free(struct stm32_i2c_dma *dma)
+{
+   dma->dma_buf = 0;
+   dma->dma_len = 0;
+
+   dma_release_channel(dma->chan_tx);
+   dma->chan_tx = NULL;
+
+   dma_release_channel(dma->chan_rx);
+   dma->chan_rx = NULL;
+
+   dma->chan_using = NULL;
+}
+
+int stm32_i2c_prep_dma_xfer(struct device *dev, struct stm32_i2c_dma *dma,
+   bool rd_wr, u32 len, u8 *buf,
+   dma_async_tx_callback callback,
+   void *dma_async_param)
+{
+   struct dma_async_tx_descriptor *txdesc;
+   struct device *chan_dev;
+   int ret;
+
+   if (rd_wr) {
+   dma->chan_using = dma->chan_rx;
+   dma->dma_transfer_dir = DMA_DEV_TO_MEM;
+   dma->dma_data_dir = DMA_FROM_DEVICE;
+   } else {
+   dma->chan_using = dma->chan_tx;
+   dma->dma_transfer_dir = DMA_MEM_TO_DEV;
+   dma->dma_data_dir = DMA_TO_DEVICE;
+   }
+
+   dma->dma_len = len;
+   chan_dev = dma->chan_using->device->dev;
+
+   dma->dma_buf = dma_map_single(chan_dev, buf, dma->dma_len,
+ dma->dma_data_dir);
+   if (dma_mapping_error(chan_dev, dma->dma_buf)) {
+   dev_err(dev, "DMA mapping failed\n");
+   return -EINVAL;
+   }
+
+   txdesc = dmaengine_prep_slave_single(dma->chan_using, dma->dma_buf,
+dma->dma_len,
+dma->dma_transfer_dir,
+DMA_PREP_INTERRUPT);
+   if (!txdesc) {
+   dev_err(dev, "Not able to get desc for DMA xfer\n");
+   ret = -EINVAL;
+   goto err;
+