On 08/05/2014 03:26 PM, Yuan Yao wrote:
(...)
+/* Functions for DMA support */
+static int i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,
+ dma_addr_t phy_addr)
should match open parenthesis...
static int i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,
dma_addr_t phy_addr)
+{
+ struct imx_i2c_dma *dma;
+ struct dma_slave_config dma_sconfig;
+ struct device *dev = &i2c_imx->adapter.dev;
+ int ret;
+
+ dma = devm_kzalloc(dev, sizeof(struct imx_i2c_dma), GFP_KERNEL);
sizeof(*dma) ....?
+ if (!dma)
+ return -ENOMEM;
+
+ dma->chan_tx = dma_request_slave_channel(dev, "tx");
+ if (!dma->chan_tx) {
+ dev_dbg(dev, "can't request DMA tx channel\n");
+ ret = -ENODEV;
+ goto fail_al;
+ }
+
+ dma_sconfig.dst_addr = phy_addr +
+ (IMX_I2C_I2DR << i2c_imx->hwdata->regshift);
+ 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, &dma_sconfig);
+ if (ret < 0) {
+ dev_dbg(dev, "can't configure tx channel\n");
+ goto fail_tx;
+ }
+
+ dma->chan_rx = dma_request_slave_channel(dev, "rx");
+ if (!dma->chan_rx) {
+ dev_dbg(dev, "can't request DMA rx channel\n");
+ ret = -ENODEV;
+ goto fail_tx;
+ }
+
+ dma_sconfig.src_addr = phy_addr +
+ (IMX_I2C_I2DR << i2c_imx->hwdata->regshift);
+ 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, &dma_sconfig);
+ if (ret < 0) {
+ dev_dbg(dev, "can't configure rx channel\n");
+ goto fail_rx;
+ }
+
+ i2c_imx->dma = dma;
+ init_completion(&dma->cmd_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 0;
+
+fail_rx:
+ dma_release_channel(dma->chan_rx);
+fail_tx:
+ dma_release_channel(dma->chan_tx);
+fail_al:
+ devm_kfree(dev, dma);
no need to use devm_kfree() if we use devm_kzalloc()...
+ dev_info(dev, "can't use DMA\n");
+
+ return ret;
+}
+
+static void i2c_imx_dma_callback(void *arg)
+{
+ struct imx_i2c_struct *i2c_imx = (struct imx_i2c_struct *)arg;
+ struct imx_i2c_dma *dma = i2c_imx->dma;
+
+ dma_unmap_single(dma->chan_using->device->dev, dma->dma_buf,
+ dma->dma_len, dma->dma_data_dir);
+ complete(&dma->cmd_complete);
+}
+
+static int i2c_imx_dma_xfer(struct imx_i2c_struct *i2c_imx,
+ struct i2c_msg *msgs)
static int i2c_imx_dma_xfer(struct imx_i2c_struct *i2c_imx,
struct i2c_msg *msgs)
+{
+ struct imx_i2c_dma *dma = i2c_imx->dma;
+ struct dma_async_tx_descriptor *txdesc;
+ struct device *dev = &i2c_imx->adapter.dev;
+ struct device *chan_dev = dma->chan_using->device->dev;
+
+ dma->dma_buf = dma_map_single(chan_dev, msgs->buf,
+ dma->dma_len, dma->dma_data_dir);
dma_map_single(chan_dev, msgs->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 | DMA_CTRL_ACK);
dmaengine_prep_slave_single(dma->chan_using, dma->dma_buf,
dma->dma_len, dma->dma_transfer_dir,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+ if (!txdesc) {
+ dev_err(dev, "Not able to get desc for DMA xfer\n");
+ dma_unmap_single(chan_dev, dma->dma_buf,
+ dma->dma_len, dma->dma_data_dir);
+ return -EINVAL;
+ }
+
+ txdesc->callback = i2c_imx_dma_callback;
+ txdesc->callback_param = i2c_imx;
+ dmaengine_submit(txdesc);
+ dma_async_issue_pending(dma->chan_using);
+
+ return 0;
+}
+
+static void i2c_imx_dma_free(struct imx_i2c_struct *i2c_imx)
+{
+ struct imx_i2c_dma *dma = i2c_imx->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;
+}
+
/** Functions for IMX I2C adapter driver ***************************************
*******************************************************************************/
@@ -379,6 +530,7 @@ static int i2c_imx_start(struct imx_i2c_struct *i2c_imx)
i2c_imx->stopped = 0;
temp |= I2CR_IIEN | I2CR_MTX | I2CR_TXAK;
+ temp &= ~I2CR_DMAEN;
imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
return result;
}
@@ -432,6 +584,160 @@ static irqreturn_t i2c_imx_isr(int irq, void *dev_id)
return IRQ_NONE;
}
+static int i2c_imx_dma_write(struct imx_i2c_struct *i2c_imx,
+ struct i2c_msg *msgs)
static int i2c_imx_dma_write(struct imx_i2c_struct *i2c_imx,
struct i2c_msg *msgs)
run checkpatch.pl on this patch...
--
Regards,
Varka Bhadram.
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