* [PATCH v3 0/2] i2c: add DMA support for freescale i2c driver
@ 2014-03-13 1:47 ` Yuan Yao
0 siblings, 0 replies; 33+ messages in thread
From: Yuan Yao @ 2014-03-13 1:47 UTC (permalink / raw)
To: wsa, marex
Cc: mark.rutland, shawn.guo, linux-kernel, linux-arm-kernel, linux-i2c
Changed in v3:
- fix a bug when request the dma faild.
- some minor fixes for coding style.
- other minor fixes.
Changed in v2:
- remove has_dma_support property
- unify i2c_imx_dma_rx and i2c_imx_dma_tx
- unify i2c_imx_dma_read and i2c_imx_pio_read
- unify i2c_imx_dma_write and i2c_imx_pio_write
Added in v1:
- Enable dma if it's support dma and transfer size bigger than the threshold.
- Add device tree bindings for i2c eDMA support.
- Add eDMA support for i2c driver.
^ permalink raw reply [flat|nested] 33+ messages in thread
* [PATCH v3 0/2] i2c: add DMA support for freescale i2c driver
@ 2014-03-13 1:47 ` Yuan Yao
0 siblings, 0 replies; 33+ messages in thread
From: Yuan Yao @ 2014-03-13 1:47 UTC (permalink / raw)
To: wsa, marex
Cc: mark.rutland, shawn.guo, linux-kernel, linux-arm-kernel, linux-i2c
Changed in v3:
- fix a bug when request the dma faild.
- some minor fixes for coding style.
- other minor fixes.
Changed in v2:
- remove has_dma_support property
- unify i2c_imx_dma_rx and i2c_imx_dma_tx
- unify i2c_imx_dma_read and i2c_imx_pio_read
- unify i2c_imx_dma_write and i2c_imx_pio_write
Added in v1:
- Enable dma if it's support dma and transfer size bigger than the threshold.
- Add device tree bindings for i2c eDMA support.
- Add eDMA support for i2c driver.
^ permalink raw reply [flat|nested] 33+ messages in thread
* [PATCH v3 0/2] i2c: add DMA support for freescale i2c driver
@ 2014-03-13 1:47 ` Yuan Yao
0 siblings, 0 replies; 33+ messages in thread
From: Yuan Yao @ 2014-03-13 1:47 UTC (permalink / raw)
To: linux-arm-kernel
Changed in v3:
- fix a bug when request the dma faild.
- some minor fixes for coding style.
- other minor fixes.
Changed in v2:
- remove has_dma_support property
- unify i2c_imx_dma_rx and i2c_imx_dma_tx
- unify i2c_imx_dma_read and i2c_imx_pio_read
- unify i2c_imx_dma_write and i2c_imx_pio_write
Added in v1:
- Enable dma if it's support dma and transfer size bigger than the threshold.
- Add device tree bindings for i2c eDMA support.
- Add eDMA support for i2c driver.
^ permalink raw reply [flat|nested] 33+ messages in thread
* [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
@ 2014-03-13 1:47 ` Yuan Yao
0 siblings, 0 replies; 33+ messages in thread
From: Yuan Yao @ 2014-03-13 1:47 UTC (permalink / raw)
To: wsa, marex
Cc: mark.rutland, shawn.guo, linux-kernel, linux-arm-kernel, linux-i2c
Add dma support for i2c. This function depend on DMA driver.
You can turn on it by write both the dmas and dma-name properties in dts node.
Signed-off-by: Yuan Yao <yao.yuan@freescale.com>
---
drivers/i2c/busses/i2c-imx.c | 354 +++++++++++++++++++++++++++++++++++++------
1 file changed, 306 insertions(+), 48 deletions(-)
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
index db895fb..6bfe23c 100644
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -37,22 +37,27 @@
/** Includes *******************************************************************
*******************************************************************************/
-#include <linux/init.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
+#include <linux/dmapool.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/interrupt.h>
-#include <linux/delay.h>
#include <linux/i2c.h>
+#include <linux/init.h>
#include <linux/io.h>
-#include <linux/sched.h>
-#include <linux/platform_device.h>
-#include <linux/clk.h>
-#include <linux/slab.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
+#include <linux/of_dma.h>
#include <linux/platform_data/i2c-imx.h>
+#include <linux/platform_device.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
/** Defines ********************************************************************
*******************************************************************************/
@@ -63,6 +68,10 @@
/* Default value */
#define IMX_I2C_BIT_RATE 100000 /* 100kHz */
+/* enable DMA if transfer byte size is bigger than this threshold */
+#define IMX_I2C_DMA_THRESHOLD 16
+#define IMX_I2C_DMA_TIMEOUT 1000
+
/* IMX I2C registers:
* the I2C register offset is different between SoCs,
* to provid support for all these chips, split the
@@ -88,6 +97,7 @@
#define I2SR_IBB 0x20
#define I2SR_IAAS 0x40
#define I2SR_ICF 0x80
+#define I2CR_DMAEN 0x02
#define I2CR_RSTA 0x04
#define I2CR_TXAK 0x08
#define I2CR_MTX 0x10
@@ -174,6 +184,17 @@ struct imx_i2c_hwdata {
unsigned i2cr_ien_opcode;
};
+struct imx_i2c_dma {
+ struct dma_chan *chan_tx;
+ struct dma_chan *chan_rx;
+ struct dma_chan *chan_using;
+ struct completion cmd_complete;
+ dma_addr_t dma_buf;
+ unsigned int dma_len;
+ unsigned int dma_transfer_dir;
+ unsigned int dma_data_dir;
+};
+
struct imx_i2c_struct {
struct i2c_adapter adapter;
struct clk *clk;
@@ -184,6 +205,9 @@ struct imx_i2c_struct {
int stopped;
unsigned int ifdr; /* IMX_I2C_IFDR */
const struct imx_i2c_hwdata *hwdata;
+
+ struct imx_i2c_dma *dma;
+ bool use_dma;
};
static const struct imx_i2c_hwdata imx1_i2c_hwdata = {
@@ -254,9 +278,121 @@ static inline unsigned char imx_i2c_read_reg(struct imx_i2c_struct *i2c_imx,
return readb(i2c_imx->base + (reg << i2c_imx->hwdata->regshift));
}
+/* Functions for DMA support */
+static int i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,
+ dma_addr_t phy_addr)
+{
+ struct imx_i2c_dma *dma = i2c_imx->dma;
+ struct dma_slave_config dma_sconfig;
+ struct device *dev = &i2c_imx->adapter.dev;
+ int ret;
+
+ dma->chan_tx = dma_request_slave_channel(dev, "tx");
+ if (!dma->chan_tx) {
+ dev_err(dev, "Dma tx channel request failed!\n");
+ return -ENODEV;
+ }
+
+ 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_err(dev, "Dma slave config failed, err = %d\n", ret);
+ goto fail_tx;
+ }
+
+ dma->chan_rx = dma_request_slave_channel(dev, "rx");
+ if (!dma->chan_rx) {
+ dev_err(dev, "Dma rx channel request failed!\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_err(dev, "Dma slave config failed, err = %d\n", ret);
+ goto fail_rx;
+ }
+
+ init_completion(&dma->cmd_complete);
+
+ return 0;
+
+fail_rx:
+ dma_release_channel(dma->chan_rx);
+fail_tx:
+ dma_release_channel(dma->chan_tx);
+ 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)
+{
+ struct imx_i2c_dma *dma = i2c_imx->dma;
+ struct dma_async_tx_descriptor *txdesc;
+ struct device *dev = &i2c_imx->adapter.dev;
+
+ dma->dma_buf = dma_map_single(dma->chan_using->device->dev, msgs->buf,
+ dma->dma_len, dma->dma_data_dir);
+ if (dma_mapping_error(dma->chan_using->device->dev, dma->dma_buf)) {
+ dev_err(dev, "dma_map_single 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);
+ if (!txdesc) {
+ dev_err(dev, "Not able to get desc for dma xfer\n");
+ dma_unmap_single(dma->chan_using->device->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 ***************************************
*******************************************************************************/
-
static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy)
{
unsigned long orig_jiffies = jiffies;
@@ -427,46 +563,103 @@ static irqreturn_t i2c_imx_isr(int irq, void *dev_id)
static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
{
- int i, result;
+ int i, result, timeout = IMX_I2C_DMA_TIMEOUT;
+ unsigned int temp = 0;
+ struct imx_i2c_dma *dma = i2c_imx->dma;
dev_dbg(&i2c_imx->adapter.dev, "<%s> write slave address: addr=0x%x\n",
__func__, msgs->addr << 1);
- /* write slave address */
- imx_i2c_write_reg(msgs->addr << 1, i2c_imx, IMX_I2C_I2DR);
- result = i2c_imx_trx_complete(i2c_imx);
- if (result)
- return result;
- result = i2c_imx_acked(i2c_imx);
- if (result)
- return result;
- dev_dbg(&i2c_imx->adapter.dev, "<%s> write data\n", __func__);
+ if (i2c_imx->use_dma && msgs->len >= IMX_I2C_DMA_THRESHOLD) {
+ reinit_completion(&i2c_imx->dma->cmd_complete);
+ dma->chan_using = dma->chan_tx;
+ dma->dma_transfer_dir = DMA_MEM_TO_DEV;
+ dma->dma_data_dir = DMA_TO_DEVICE;
+ dma->dma_len = msgs->len - 1;
+ result = i2c_imx_dma_xfer(i2c_imx, msgs);
+ if (result)
+ return result;
- /* write data */
- for (i = 0; i < msgs->len; i++) {
- dev_dbg(&i2c_imx->adapter.dev,
- "<%s> write byte: B%d=0x%X\n",
- __func__, i, msgs->buf[i]);
- imx_i2c_write_reg(msgs->buf[i], i2c_imx, IMX_I2C_I2DR);
+ temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
+ temp |= I2CR_DMAEN;
+ imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
+
+ /* write slave address */
+ imx_i2c_write_reg(msgs->addr << 1, i2c_imx, IMX_I2C_I2DR);
+ result = wait_for_completion_interruptible_timeout(
+ &i2c_imx->dma->cmd_complete,
+ msecs_to_jiffies(IMX_I2C_DMA_TIMEOUT));
+ if (result <= 0) {
+ dmaengine_terminate_all(dma->chan_using);
+ if (result)
+ return result;
+ else
+ return -ETIMEDOUT;
+ }
+
+ /* waiting for Transfer complete. */
+ while (timeout--) {
+ temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
+ if (temp & I2SR_ICF)
+ break;
+ udelay(10);
+ }
+
+ temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
+ temp &= ~I2CR_DMAEN;
+ imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
+
+ /* write the last byte */
+ imx_i2c_write_reg(msgs->buf[msgs->len-1],
+ i2c_imx, IMX_I2C_I2DR);
result = i2c_imx_trx_complete(i2c_imx);
if (result)
return result;
+
result = i2c_imx_acked(i2c_imx);
if (result)
return result;
+ } else {
+ /* write slave address */
+ imx_i2c_write_reg(msgs->addr << 1, i2c_imx, IMX_I2C_I2DR);
+ result = i2c_imx_trx_complete(i2c_imx);
+ if (result)
+ return result;
+
+ result = i2c_imx_acked(i2c_imx);
+ if (result)
+ return result;
+
+ dev_dbg(&i2c_imx->adapter.dev, "<%s> write data\n", __func__);
+
+ /* write data */
+ for (i = 0; i < msgs->len; i++) {
+ dev_dbg(&i2c_imx->adapter.dev,
+ "<%s> write byte: B%d=0x%X\n",
+ __func__, i, msgs->buf[i]);
+ imx_i2c_write_reg(msgs->buf[i], i2c_imx, IMX_I2C_I2DR);
+ result = i2c_imx_trx_complete(i2c_imx);
+ if (result)
+ return result;
+ result = i2c_imx_acked(i2c_imx);
+ if (result)
+ return result;
+ }
}
return 0;
}
static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
{
- int i, result;
+ int i, result, timeout = IMX_I2C_DMA_TIMEOUT;
unsigned int temp;
+ struct imx_i2c_dma *dma = i2c_imx->dma;
dev_dbg(&i2c_imx->adapter.dev,
"<%s> write slave address: addr=0x%x\n",
__func__, (msgs->addr << 1) | 0x01);
+
/* write slave address */
imx_i2c_write_reg((msgs->addr << 1) | 0x01, i2c_imx, IMX_I2C_I2DR);
result = i2c_imx_trx_complete(i2c_imx);
@@ -488,33 +681,78 @@ static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
dev_dbg(&i2c_imx->adapter.dev, "<%s> read data\n", __func__);
- /* read data */
- for (i = 0; i < msgs->len; i++) {
- result = i2c_imx_trx_complete(i2c_imx);
+ if (i2c_imx->use_dma && msgs->len >= IMX_I2C_DMA_THRESHOLD) {
+ temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
+ temp |= I2CR_DMAEN;
+ imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
+
+ reinit_completion(&i2c_imx->dma->cmd_complete);
+ dma->chan_using = dma->chan_rx;
+ dma->dma_transfer_dir = DMA_DEV_TO_MEM;
+ dma->dma_data_dir = DMA_FROM_DEVICE;
+ dma->dma_len = msgs->len - 2;
+ result = i2c_imx_dma_xfer(i2c_imx, msgs);
if (result)
return result;
- if (i == (msgs->len - 1)) {
- /* It must generate STOP before read I2DR to prevent
- controller from generating another clock cycle */
- dev_dbg(&i2c_imx->adapter.dev,
- "<%s> clear MSTA\n", __func__);
- temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
- temp &= ~(I2CR_MSTA | I2CR_MTX);
- imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
- i2c_imx_bus_busy(i2c_imx, 0);
- i2c_imx->stopped = 1;
- } else if (i == (msgs->len - 2)) {
+
+ result = wait_for_completion_interruptible_timeout(
+ &i2c_imx->dma->cmd_complete,
+ msecs_to_jiffies(IMX_I2C_DMA_TIMEOUT));
+ if (result <= 0) {
+ dmaengine_terminate_all(dma->chan_using);
+ if (result)
+ return result;
+ else
+ return -ETIMEDOUT;
+ }
+
+ /* waiting for Transfer complete. */
+ while (timeout--) {
+ temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
+ if (temp & I2SR_ICF)
+ break;
+ udelay(10);
+ }
+
+ temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
+ temp &= ~I2CR_DMAEN;
+ imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
+ } else {
+ /* read data */
+ for (i = 0; i < msgs->len - 2; i++) {
+ result = i2c_imx_trx_complete(i2c_imx);
+ if (result)
+ return result;
+ msgs->buf[i] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
dev_dbg(&i2c_imx->adapter.dev,
- "<%s> set TXAK\n", __func__);
- temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
- temp |= I2CR_TXAK;
- imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
+ "<%s> read byte: B%d=0x%X\n",
+ __func__, i, msgs->buf[i]);
}
- msgs->buf[i] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
- dev_dbg(&i2c_imx->adapter.dev,
- "<%s> read byte: B%d=0x%X\n",
- __func__, i, msgs->buf[i]);
+ result = i2c_imx_trx_complete(i2c_imx);
}
+
+ /* read n-1 byte data */
+ temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
+ temp |= I2CR_TXAK;
+ imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
+
+ msgs->buf[msgs->len-2] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
+ /* read n byte data */
+ result = i2c_imx_trx_complete(i2c_imx);
+ if (result)
+ return result;
+
+ /*
+ * It must generate STOP before read I2DR to prevent
+ * controller from generating another clock cycle
+ */
+ temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
+ temp &= ~(I2CR_MSTA | I2CR_MTX);
+ imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
+ i2c_imx_bus_busy(i2c_imx, 0);
+ i2c_imx->stopped = 1;
+ msgs->buf[msgs->len-1] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
+
return 0;
}
@@ -601,6 +839,7 @@ static int i2c_imx_probe(struct platform_device *pdev)
void __iomem *base;
int irq, ret;
u32 bitrate;
+ u32 phy_addr;
dev_dbg(&pdev->dev, "<%s>\n", __func__);
@@ -611,6 +850,7 @@ static int i2c_imx_probe(struct platform_device *pdev)
}
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ phy_addr = res->start;
base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(base))
return PTR_ERR(base);
@@ -696,6 +936,21 @@ static int i2c_imx_probe(struct platform_device *pdev)
i2c_imx->adapter.name);
dev_info(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n");
+ /* Init DMA config if support*/
+ i2c_imx->dma = devm_kzalloc(&pdev->dev, sizeof(struct imx_i2c_dma),
+ GFP_KERNEL);
+ if (!i2c_imx->dma) {
+ dev_info(&pdev->dev,
+ "can't allocate dma struct faild use dma.\n");
+ i2c_imx->use_dma = false;
+ } else if (i2c_imx_dma_request(i2c_imx, (dma_addr_t)phy_addr)) {
+ dev_info(&pdev->dev,
+ "can't request dma chan, faild use dma.\n");
+ i2c_imx->use_dma = false;
+ } else {
+ i2c_imx->use_dma = true;
+ }
+
return 0; /* Return OK */
}
@@ -707,6 +962,9 @@ static int i2c_imx_remove(struct platform_device *pdev)
dev_dbg(&i2c_imx->adapter.dev, "adapter removed\n");
i2c_del_adapter(&i2c_imx->adapter);
+ if (i2c_imx->use_dma)
+ i2c_imx_dma_free(i2c_imx);
+
/* setup chip registers to defaults */
imx_i2c_write_reg(0, i2c_imx, IMX_I2C_IADR);
imx_i2c_write_reg(0, i2c_imx, IMX_I2C_IFDR);
--
1.8.4
^ permalink raw reply related [flat|nested] 33+ messages in thread
* [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
@ 2014-03-13 1:47 ` Yuan Yao
0 siblings, 0 replies; 33+ messages in thread
From: Yuan Yao @ 2014-03-13 1:47 UTC (permalink / raw)
To: wsa-z923LK4zBo2bacvFa/9K2g, marex-ynQEQJNshbs
Cc: mark.rutland-5wv7dgnIgG8, shawn.guo-QSEj5FYQhm4dnm+yROfE0A,
linux-kernel-u79uwXL29TY76Z2rM5mHXA,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
linux-i2c-u79uwXL29TY76Z2rM5mHXA
Add dma support for i2c. This function depend on DMA driver.
You can turn on it by write both the dmas and dma-name properties in dts node.
Signed-off-by: Yuan Yao <yao.yuan-KZfg59tc24xl57MIdRCFDg@public.gmane.org>
---
drivers/i2c/busses/i2c-imx.c | 354 +++++++++++++++++++++++++++++++++++++------
1 file changed, 306 insertions(+), 48 deletions(-)
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
index db895fb..6bfe23c 100644
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -37,22 +37,27 @@
/** Includes *******************************************************************
*******************************************************************************/
-#include <linux/init.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
+#include <linux/dmapool.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/interrupt.h>
-#include <linux/delay.h>
#include <linux/i2c.h>
+#include <linux/init.h>
#include <linux/io.h>
-#include <linux/sched.h>
-#include <linux/platform_device.h>
-#include <linux/clk.h>
-#include <linux/slab.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
+#include <linux/of_dma.h>
#include <linux/platform_data/i2c-imx.h>
+#include <linux/platform_device.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
/** Defines ********************************************************************
*******************************************************************************/
@@ -63,6 +68,10 @@
/* Default value */
#define IMX_I2C_BIT_RATE 100000 /* 100kHz */
+/* enable DMA if transfer byte size is bigger than this threshold */
+#define IMX_I2C_DMA_THRESHOLD 16
+#define IMX_I2C_DMA_TIMEOUT 1000
+
/* IMX I2C registers:
* the I2C register offset is different between SoCs,
* to provid support for all these chips, split the
@@ -88,6 +97,7 @@
#define I2SR_IBB 0x20
#define I2SR_IAAS 0x40
#define I2SR_ICF 0x80
+#define I2CR_DMAEN 0x02
#define I2CR_RSTA 0x04
#define I2CR_TXAK 0x08
#define I2CR_MTX 0x10
@@ -174,6 +184,17 @@ struct imx_i2c_hwdata {
unsigned i2cr_ien_opcode;
};
+struct imx_i2c_dma {
+ struct dma_chan *chan_tx;
+ struct dma_chan *chan_rx;
+ struct dma_chan *chan_using;
+ struct completion cmd_complete;
+ dma_addr_t dma_buf;
+ unsigned int dma_len;
+ unsigned int dma_transfer_dir;
+ unsigned int dma_data_dir;
+};
+
struct imx_i2c_struct {
struct i2c_adapter adapter;
struct clk *clk;
@@ -184,6 +205,9 @@ struct imx_i2c_struct {
int stopped;
unsigned int ifdr; /* IMX_I2C_IFDR */
const struct imx_i2c_hwdata *hwdata;
+
+ struct imx_i2c_dma *dma;
+ bool use_dma;
};
static const struct imx_i2c_hwdata imx1_i2c_hwdata = {
@@ -254,9 +278,121 @@ static inline unsigned char imx_i2c_read_reg(struct imx_i2c_struct *i2c_imx,
return readb(i2c_imx->base + (reg << i2c_imx->hwdata->regshift));
}
+/* Functions for DMA support */
+static int i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,
+ dma_addr_t phy_addr)
+{
+ struct imx_i2c_dma *dma = i2c_imx->dma;
+ struct dma_slave_config dma_sconfig;
+ struct device *dev = &i2c_imx->adapter.dev;
+ int ret;
+
+ dma->chan_tx = dma_request_slave_channel(dev, "tx");
+ if (!dma->chan_tx) {
+ dev_err(dev, "Dma tx channel request failed!\n");
+ return -ENODEV;
+ }
+
+ 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_err(dev, "Dma slave config failed, err = %d\n", ret);
+ goto fail_tx;
+ }
+
+ dma->chan_rx = dma_request_slave_channel(dev, "rx");
+ if (!dma->chan_rx) {
+ dev_err(dev, "Dma rx channel request failed!\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_err(dev, "Dma slave config failed, err = %d\n", ret);
+ goto fail_rx;
+ }
+
+ init_completion(&dma->cmd_complete);
+
+ return 0;
+
+fail_rx:
+ dma_release_channel(dma->chan_rx);
+fail_tx:
+ dma_release_channel(dma->chan_tx);
+ 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)
+{
+ struct imx_i2c_dma *dma = i2c_imx->dma;
+ struct dma_async_tx_descriptor *txdesc;
+ struct device *dev = &i2c_imx->adapter.dev;
+
+ dma->dma_buf = dma_map_single(dma->chan_using->device->dev, msgs->buf,
+ dma->dma_len, dma->dma_data_dir);
+ if (dma_mapping_error(dma->chan_using->device->dev, dma->dma_buf)) {
+ dev_err(dev, "dma_map_single 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);
+ if (!txdesc) {
+ dev_err(dev, "Not able to get desc for dma xfer\n");
+ dma_unmap_single(dma->chan_using->device->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 ***************************************
*******************************************************************************/
-
static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy)
{
unsigned long orig_jiffies = jiffies;
@@ -427,46 +563,103 @@ static irqreturn_t i2c_imx_isr(int irq, void *dev_id)
static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
{
- int i, result;
+ int i, result, timeout = IMX_I2C_DMA_TIMEOUT;
+ unsigned int temp = 0;
+ struct imx_i2c_dma *dma = i2c_imx->dma;
dev_dbg(&i2c_imx->adapter.dev, "<%s> write slave address: addr=0x%x\n",
__func__, msgs->addr << 1);
- /* write slave address */
- imx_i2c_write_reg(msgs->addr << 1, i2c_imx, IMX_I2C_I2DR);
- result = i2c_imx_trx_complete(i2c_imx);
- if (result)
- return result;
- result = i2c_imx_acked(i2c_imx);
- if (result)
- return result;
- dev_dbg(&i2c_imx->adapter.dev, "<%s> write data\n", __func__);
+ if (i2c_imx->use_dma && msgs->len >= IMX_I2C_DMA_THRESHOLD) {
+ reinit_completion(&i2c_imx->dma->cmd_complete);
+ dma->chan_using = dma->chan_tx;
+ dma->dma_transfer_dir = DMA_MEM_TO_DEV;
+ dma->dma_data_dir = DMA_TO_DEVICE;
+ dma->dma_len = msgs->len - 1;
+ result = i2c_imx_dma_xfer(i2c_imx, msgs);
+ if (result)
+ return result;
- /* write data */
- for (i = 0; i < msgs->len; i++) {
- dev_dbg(&i2c_imx->adapter.dev,
- "<%s> write byte: B%d=0x%X\n",
- __func__, i, msgs->buf[i]);
- imx_i2c_write_reg(msgs->buf[i], i2c_imx, IMX_I2C_I2DR);
+ temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
+ temp |= I2CR_DMAEN;
+ imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
+
+ /* write slave address */
+ imx_i2c_write_reg(msgs->addr << 1, i2c_imx, IMX_I2C_I2DR);
+ result = wait_for_completion_interruptible_timeout(
+ &i2c_imx->dma->cmd_complete,
+ msecs_to_jiffies(IMX_I2C_DMA_TIMEOUT));
+ if (result <= 0) {
+ dmaengine_terminate_all(dma->chan_using);
+ if (result)
+ return result;
+ else
+ return -ETIMEDOUT;
+ }
+
+ /* waiting for Transfer complete. */
+ while (timeout--) {
+ temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
+ if (temp & I2SR_ICF)
+ break;
+ udelay(10);
+ }
+
+ temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
+ temp &= ~I2CR_DMAEN;
+ imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
+
+ /* write the last byte */
+ imx_i2c_write_reg(msgs->buf[msgs->len-1],
+ i2c_imx, IMX_I2C_I2DR);
result = i2c_imx_trx_complete(i2c_imx);
if (result)
return result;
+
result = i2c_imx_acked(i2c_imx);
if (result)
return result;
+ } else {
+ /* write slave address */
+ imx_i2c_write_reg(msgs->addr << 1, i2c_imx, IMX_I2C_I2DR);
+ result = i2c_imx_trx_complete(i2c_imx);
+ if (result)
+ return result;
+
+ result = i2c_imx_acked(i2c_imx);
+ if (result)
+ return result;
+
+ dev_dbg(&i2c_imx->adapter.dev, "<%s> write data\n", __func__);
+
+ /* write data */
+ for (i = 0; i < msgs->len; i++) {
+ dev_dbg(&i2c_imx->adapter.dev,
+ "<%s> write byte: B%d=0x%X\n",
+ __func__, i, msgs->buf[i]);
+ imx_i2c_write_reg(msgs->buf[i], i2c_imx, IMX_I2C_I2DR);
+ result = i2c_imx_trx_complete(i2c_imx);
+ if (result)
+ return result;
+ result = i2c_imx_acked(i2c_imx);
+ if (result)
+ return result;
+ }
}
return 0;
}
static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
{
- int i, result;
+ int i, result, timeout = IMX_I2C_DMA_TIMEOUT;
unsigned int temp;
+ struct imx_i2c_dma *dma = i2c_imx->dma;
dev_dbg(&i2c_imx->adapter.dev,
"<%s> write slave address: addr=0x%x\n",
__func__, (msgs->addr << 1) | 0x01);
+
/* write slave address */
imx_i2c_write_reg((msgs->addr << 1) | 0x01, i2c_imx, IMX_I2C_I2DR);
result = i2c_imx_trx_complete(i2c_imx);
@@ -488,33 +681,78 @@ static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
dev_dbg(&i2c_imx->adapter.dev, "<%s> read data\n", __func__);
- /* read data */
- for (i = 0; i < msgs->len; i++) {
- result = i2c_imx_trx_complete(i2c_imx);
+ if (i2c_imx->use_dma && msgs->len >= IMX_I2C_DMA_THRESHOLD) {
+ temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
+ temp |= I2CR_DMAEN;
+ imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
+
+ reinit_completion(&i2c_imx->dma->cmd_complete);
+ dma->chan_using = dma->chan_rx;
+ dma->dma_transfer_dir = DMA_DEV_TO_MEM;
+ dma->dma_data_dir = DMA_FROM_DEVICE;
+ dma->dma_len = msgs->len - 2;
+ result = i2c_imx_dma_xfer(i2c_imx, msgs);
if (result)
return result;
- if (i == (msgs->len - 1)) {
- /* It must generate STOP before read I2DR to prevent
- controller from generating another clock cycle */
- dev_dbg(&i2c_imx->adapter.dev,
- "<%s> clear MSTA\n", __func__);
- temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
- temp &= ~(I2CR_MSTA | I2CR_MTX);
- imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
- i2c_imx_bus_busy(i2c_imx, 0);
- i2c_imx->stopped = 1;
- } else if (i == (msgs->len - 2)) {
+
+ result = wait_for_completion_interruptible_timeout(
+ &i2c_imx->dma->cmd_complete,
+ msecs_to_jiffies(IMX_I2C_DMA_TIMEOUT));
+ if (result <= 0) {
+ dmaengine_terminate_all(dma->chan_using);
+ if (result)
+ return result;
+ else
+ return -ETIMEDOUT;
+ }
+
+ /* waiting for Transfer complete. */
+ while (timeout--) {
+ temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
+ if (temp & I2SR_ICF)
+ break;
+ udelay(10);
+ }
+
+ temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
+ temp &= ~I2CR_DMAEN;
+ imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
+ } else {
+ /* read data */
+ for (i = 0; i < msgs->len - 2; i++) {
+ result = i2c_imx_trx_complete(i2c_imx);
+ if (result)
+ return result;
+ msgs->buf[i] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
dev_dbg(&i2c_imx->adapter.dev,
- "<%s> set TXAK\n", __func__);
- temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
- temp |= I2CR_TXAK;
- imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
+ "<%s> read byte: B%d=0x%X\n",
+ __func__, i, msgs->buf[i]);
}
- msgs->buf[i] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
- dev_dbg(&i2c_imx->adapter.dev,
- "<%s> read byte: B%d=0x%X\n",
- __func__, i, msgs->buf[i]);
+ result = i2c_imx_trx_complete(i2c_imx);
}
+
+ /* read n-1 byte data */
+ temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
+ temp |= I2CR_TXAK;
+ imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
+
+ msgs->buf[msgs->len-2] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
+ /* read n byte data */
+ result = i2c_imx_trx_complete(i2c_imx);
+ if (result)
+ return result;
+
+ /*
+ * It must generate STOP before read I2DR to prevent
+ * controller from generating another clock cycle
+ */
+ temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
+ temp &= ~(I2CR_MSTA | I2CR_MTX);
+ imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
+ i2c_imx_bus_busy(i2c_imx, 0);
+ i2c_imx->stopped = 1;
+ msgs->buf[msgs->len-1] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
+
return 0;
}
@@ -601,6 +839,7 @@ static int i2c_imx_probe(struct platform_device *pdev)
void __iomem *base;
int irq, ret;
u32 bitrate;
+ u32 phy_addr;
dev_dbg(&pdev->dev, "<%s>\n", __func__);
@@ -611,6 +850,7 @@ static int i2c_imx_probe(struct platform_device *pdev)
}
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ phy_addr = res->start;
base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(base))
return PTR_ERR(base);
@@ -696,6 +936,21 @@ static int i2c_imx_probe(struct platform_device *pdev)
i2c_imx->adapter.name);
dev_info(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n");
+ /* Init DMA config if support*/
+ i2c_imx->dma = devm_kzalloc(&pdev->dev, sizeof(struct imx_i2c_dma),
+ GFP_KERNEL);
+ if (!i2c_imx->dma) {
+ dev_info(&pdev->dev,
+ "can't allocate dma struct faild use dma.\n");
+ i2c_imx->use_dma = false;
+ } else if (i2c_imx_dma_request(i2c_imx, (dma_addr_t)phy_addr)) {
+ dev_info(&pdev->dev,
+ "can't request dma chan, faild use dma.\n");
+ i2c_imx->use_dma = false;
+ } else {
+ i2c_imx->use_dma = true;
+ }
+
return 0; /* Return OK */
}
@@ -707,6 +962,9 @@ static int i2c_imx_remove(struct platform_device *pdev)
dev_dbg(&i2c_imx->adapter.dev, "adapter removed\n");
i2c_del_adapter(&i2c_imx->adapter);
+ if (i2c_imx->use_dma)
+ i2c_imx_dma_free(i2c_imx);
+
/* setup chip registers to defaults */
imx_i2c_write_reg(0, i2c_imx, IMX_I2C_IADR);
imx_i2c_write_reg(0, i2c_imx, IMX_I2C_IFDR);
--
1.8.4
^ permalink raw reply related [flat|nested] 33+ messages in thread
* [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
@ 2014-03-13 1:47 ` Yuan Yao
0 siblings, 0 replies; 33+ messages in thread
From: Yuan Yao @ 2014-03-13 1:47 UTC (permalink / raw)
To: linux-arm-kernel
Add dma support for i2c. This function depend on DMA driver.
You can turn on it by write both the dmas and dma-name properties in dts node.
Signed-off-by: Yuan Yao <yao.yuan@freescale.com>
---
drivers/i2c/busses/i2c-imx.c | 354 +++++++++++++++++++++++++++++++++++++------
1 file changed, 306 insertions(+), 48 deletions(-)
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
index db895fb..6bfe23c 100644
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -37,22 +37,27 @@
/** Includes *******************************************************************
*******************************************************************************/
-#include <linux/init.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
+#include <linux/dmapool.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/interrupt.h>
-#include <linux/delay.h>
#include <linux/i2c.h>
+#include <linux/init.h>
#include <linux/io.h>
-#include <linux/sched.h>
-#include <linux/platform_device.h>
-#include <linux/clk.h>
-#include <linux/slab.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
+#include <linux/of_dma.h>
#include <linux/platform_data/i2c-imx.h>
+#include <linux/platform_device.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
/** Defines ********************************************************************
*******************************************************************************/
@@ -63,6 +68,10 @@
/* Default value */
#define IMX_I2C_BIT_RATE 100000 /* 100kHz */
+/* enable DMA if transfer byte size is bigger than this threshold */
+#define IMX_I2C_DMA_THRESHOLD 16
+#define IMX_I2C_DMA_TIMEOUT 1000
+
/* IMX I2C registers:
* the I2C register offset is different between SoCs,
* to provid support for all these chips, split the
@@ -88,6 +97,7 @@
#define I2SR_IBB 0x20
#define I2SR_IAAS 0x40
#define I2SR_ICF 0x80
+#define I2CR_DMAEN 0x02
#define I2CR_RSTA 0x04
#define I2CR_TXAK 0x08
#define I2CR_MTX 0x10
@@ -174,6 +184,17 @@ struct imx_i2c_hwdata {
unsigned i2cr_ien_opcode;
};
+struct imx_i2c_dma {
+ struct dma_chan *chan_tx;
+ struct dma_chan *chan_rx;
+ struct dma_chan *chan_using;
+ struct completion cmd_complete;
+ dma_addr_t dma_buf;
+ unsigned int dma_len;
+ unsigned int dma_transfer_dir;
+ unsigned int dma_data_dir;
+};
+
struct imx_i2c_struct {
struct i2c_adapter adapter;
struct clk *clk;
@@ -184,6 +205,9 @@ struct imx_i2c_struct {
int stopped;
unsigned int ifdr; /* IMX_I2C_IFDR */
const struct imx_i2c_hwdata *hwdata;
+
+ struct imx_i2c_dma *dma;
+ bool use_dma;
};
static const struct imx_i2c_hwdata imx1_i2c_hwdata = {
@@ -254,9 +278,121 @@ static inline unsigned char imx_i2c_read_reg(struct imx_i2c_struct *i2c_imx,
return readb(i2c_imx->base + (reg << i2c_imx->hwdata->regshift));
}
+/* Functions for DMA support */
+static int i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,
+ dma_addr_t phy_addr)
+{
+ struct imx_i2c_dma *dma = i2c_imx->dma;
+ struct dma_slave_config dma_sconfig;
+ struct device *dev = &i2c_imx->adapter.dev;
+ int ret;
+
+ dma->chan_tx = dma_request_slave_channel(dev, "tx");
+ if (!dma->chan_tx) {
+ dev_err(dev, "Dma tx channel request failed!\n");
+ return -ENODEV;
+ }
+
+ 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_err(dev, "Dma slave config failed, err = %d\n", ret);
+ goto fail_tx;
+ }
+
+ dma->chan_rx = dma_request_slave_channel(dev, "rx");
+ if (!dma->chan_rx) {
+ dev_err(dev, "Dma rx channel request failed!\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_err(dev, "Dma slave config failed, err = %d\n", ret);
+ goto fail_rx;
+ }
+
+ init_completion(&dma->cmd_complete);
+
+ return 0;
+
+fail_rx:
+ dma_release_channel(dma->chan_rx);
+fail_tx:
+ dma_release_channel(dma->chan_tx);
+ 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)
+{
+ struct imx_i2c_dma *dma = i2c_imx->dma;
+ struct dma_async_tx_descriptor *txdesc;
+ struct device *dev = &i2c_imx->adapter.dev;
+
+ dma->dma_buf = dma_map_single(dma->chan_using->device->dev, msgs->buf,
+ dma->dma_len, dma->dma_data_dir);
+ if (dma_mapping_error(dma->chan_using->device->dev, dma->dma_buf)) {
+ dev_err(dev, "dma_map_single 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);
+ if (!txdesc) {
+ dev_err(dev, "Not able to get desc for dma xfer\n");
+ dma_unmap_single(dma->chan_using->device->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 ***************************************
*******************************************************************************/
-
static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy)
{
unsigned long orig_jiffies = jiffies;
@@ -427,46 +563,103 @@ static irqreturn_t i2c_imx_isr(int irq, void *dev_id)
static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
{
- int i, result;
+ int i, result, timeout = IMX_I2C_DMA_TIMEOUT;
+ unsigned int temp = 0;
+ struct imx_i2c_dma *dma = i2c_imx->dma;
dev_dbg(&i2c_imx->adapter.dev, "<%s> write slave address: addr=0x%x\n",
__func__, msgs->addr << 1);
- /* write slave address */
- imx_i2c_write_reg(msgs->addr << 1, i2c_imx, IMX_I2C_I2DR);
- result = i2c_imx_trx_complete(i2c_imx);
- if (result)
- return result;
- result = i2c_imx_acked(i2c_imx);
- if (result)
- return result;
- dev_dbg(&i2c_imx->adapter.dev, "<%s> write data\n", __func__);
+ if (i2c_imx->use_dma && msgs->len >= IMX_I2C_DMA_THRESHOLD) {
+ reinit_completion(&i2c_imx->dma->cmd_complete);
+ dma->chan_using = dma->chan_tx;
+ dma->dma_transfer_dir = DMA_MEM_TO_DEV;
+ dma->dma_data_dir = DMA_TO_DEVICE;
+ dma->dma_len = msgs->len - 1;
+ result = i2c_imx_dma_xfer(i2c_imx, msgs);
+ if (result)
+ return result;
- /* write data */
- for (i = 0; i < msgs->len; i++) {
- dev_dbg(&i2c_imx->adapter.dev,
- "<%s> write byte: B%d=0x%X\n",
- __func__, i, msgs->buf[i]);
- imx_i2c_write_reg(msgs->buf[i], i2c_imx, IMX_I2C_I2DR);
+ temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
+ temp |= I2CR_DMAEN;
+ imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
+
+ /* write slave address */
+ imx_i2c_write_reg(msgs->addr << 1, i2c_imx, IMX_I2C_I2DR);
+ result = wait_for_completion_interruptible_timeout(
+ &i2c_imx->dma->cmd_complete,
+ msecs_to_jiffies(IMX_I2C_DMA_TIMEOUT));
+ if (result <= 0) {
+ dmaengine_terminate_all(dma->chan_using);
+ if (result)
+ return result;
+ else
+ return -ETIMEDOUT;
+ }
+
+ /* waiting for Transfer complete. */
+ while (timeout--) {
+ temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
+ if (temp & I2SR_ICF)
+ break;
+ udelay(10);
+ }
+
+ temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
+ temp &= ~I2CR_DMAEN;
+ imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
+
+ /* write the last byte */
+ imx_i2c_write_reg(msgs->buf[msgs->len-1],
+ i2c_imx, IMX_I2C_I2DR);
result = i2c_imx_trx_complete(i2c_imx);
if (result)
return result;
+
result = i2c_imx_acked(i2c_imx);
if (result)
return result;
+ } else {
+ /* write slave address */
+ imx_i2c_write_reg(msgs->addr << 1, i2c_imx, IMX_I2C_I2DR);
+ result = i2c_imx_trx_complete(i2c_imx);
+ if (result)
+ return result;
+
+ result = i2c_imx_acked(i2c_imx);
+ if (result)
+ return result;
+
+ dev_dbg(&i2c_imx->adapter.dev, "<%s> write data\n", __func__);
+
+ /* write data */
+ for (i = 0; i < msgs->len; i++) {
+ dev_dbg(&i2c_imx->adapter.dev,
+ "<%s> write byte: B%d=0x%X\n",
+ __func__, i, msgs->buf[i]);
+ imx_i2c_write_reg(msgs->buf[i], i2c_imx, IMX_I2C_I2DR);
+ result = i2c_imx_trx_complete(i2c_imx);
+ if (result)
+ return result;
+ result = i2c_imx_acked(i2c_imx);
+ if (result)
+ return result;
+ }
}
return 0;
}
static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
{
- int i, result;
+ int i, result, timeout = IMX_I2C_DMA_TIMEOUT;
unsigned int temp;
+ struct imx_i2c_dma *dma = i2c_imx->dma;
dev_dbg(&i2c_imx->adapter.dev,
"<%s> write slave address: addr=0x%x\n",
__func__, (msgs->addr << 1) | 0x01);
+
/* write slave address */
imx_i2c_write_reg((msgs->addr << 1) | 0x01, i2c_imx, IMX_I2C_I2DR);
result = i2c_imx_trx_complete(i2c_imx);
@@ -488,33 +681,78 @@ static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs)
dev_dbg(&i2c_imx->adapter.dev, "<%s> read data\n", __func__);
- /* read data */
- for (i = 0; i < msgs->len; i++) {
- result = i2c_imx_trx_complete(i2c_imx);
+ if (i2c_imx->use_dma && msgs->len >= IMX_I2C_DMA_THRESHOLD) {
+ temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
+ temp |= I2CR_DMAEN;
+ imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
+
+ reinit_completion(&i2c_imx->dma->cmd_complete);
+ dma->chan_using = dma->chan_rx;
+ dma->dma_transfer_dir = DMA_DEV_TO_MEM;
+ dma->dma_data_dir = DMA_FROM_DEVICE;
+ dma->dma_len = msgs->len - 2;
+ result = i2c_imx_dma_xfer(i2c_imx, msgs);
if (result)
return result;
- if (i == (msgs->len - 1)) {
- /* It must generate STOP before read I2DR to prevent
- controller from generating another clock cycle */
- dev_dbg(&i2c_imx->adapter.dev,
- "<%s> clear MSTA\n", __func__);
- temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
- temp &= ~(I2CR_MSTA | I2CR_MTX);
- imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
- i2c_imx_bus_busy(i2c_imx, 0);
- i2c_imx->stopped = 1;
- } else if (i == (msgs->len - 2)) {
+
+ result = wait_for_completion_interruptible_timeout(
+ &i2c_imx->dma->cmd_complete,
+ msecs_to_jiffies(IMX_I2C_DMA_TIMEOUT));
+ if (result <= 0) {
+ dmaengine_terminate_all(dma->chan_using);
+ if (result)
+ return result;
+ else
+ return -ETIMEDOUT;
+ }
+
+ /* waiting for Transfer complete. */
+ while (timeout--) {
+ temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
+ if (temp & I2SR_ICF)
+ break;
+ udelay(10);
+ }
+
+ temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
+ temp &= ~I2CR_DMAEN;
+ imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
+ } else {
+ /* read data */
+ for (i = 0; i < msgs->len - 2; i++) {
+ result = i2c_imx_trx_complete(i2c_imx);
+ if (result)
+ return result;
+ msgs->buf[i] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
dev_dbg(&i2c_imx->adapter.dev,
- "<%s> set TXAK\n", __func__);
- temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
- temp |= I2CR_TXAK;
- imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
+ "<%s> read byte: B%d=0x%X\n",
+ __func__, i, msgs->buf[i]);
}
- msgs->buf[i] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
- dev_dbg(&i2c_imx->adapter.dev,
- "<%s> read byte: B%d=0x%X\n",
- __func__, i, msgs->buf[i]);
+ result = i2c_imx_trx_complete(i2c_imx);
}
+
+ /* read n-1 byte data */
+ temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
+ temp |= I2CR_TXAK;
+ imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
+
+ msgs->buf[msgs->len-2] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
+ /* read n byte data */
+ result = i2c_imx_trx_complete(i2c_imx);
+ if (result)
+ return result;
+
+ /*
+ * It must generate STOP before read I2DR to prevent
+ * controller from generating another clock cycle
+ */
+ temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
+ temp &= ~(I2CR_MSTA | I2CR_MTX);
+ imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
+ i2c_imx_bus_busy(i2c_imx, 0);
+ i2c_imx->stopped = 1;
+ msgs->buf[msgs->len-1] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
+
return 0;
}
@@ -601,6 +839,7 @@ static int i2c_imx_probe(struct platform_device *pdev)
void __iomem *base;
int irq, ret;
u32 bitrate;
+ u32 phy_addr;
dev_dbg(&pdev->dev, "<%s>\n", __func__);
@@ -611,6 +850,7 @@ static int i2c_imx_probe(struct platform_device *pdev)
}
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ phy_addr = res->start;
base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(base))
return PTR_ERR(base);
@@ -696,6 +936,21 @@ static int i2c_imx_probe(struct platform_device *pdev)
i2c_imx->adapter.name);
dev_info(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n");
+ /* Init DMA config if support*/
+ i2c_imx->dma = devm_kzalloc(&pdev->dev, sizeof(struct imx_i2c_dma),
+ GFP_KERNEL);
+ if (!i2c_imx->dma) {
+ dev_info(&pdev->dev,
+ "can't allocate dma struct faild use dma.\n");
+ i2c_imx->use_dma = false;
+ } else if (i2c_imx_dma_request(i2c_imx, (dma_addr_t)phy_addr)) {
+ dev_info(&pdev->dev,
+ "can't request dma chan, faild use dma.\n");
+ i2c_imx->use_dma = false;
+ } else {
+ i2c_imx->use_dma = true;
+ }
+
return 0; /* Return OK */
}
@@ -707,6 +962,9 @@ static int i2c_imx_remove(struct platform_device *pdev)
dev_dbg(&i2c_imx->adapter.dev, "adapter removed\n");
i2c_del_adapter(&i2c_imx->adapter);
+ if (i2c_imx->use_dma)
+ i2c_imx_dma_free(i2c_imx);
+
/* setup chip registers to defaults */
imx_i2c_write_reg(0, i2c_imx, IMX_I2C_IADR);
imx_i2c_write_reg(0, i2c_imx, IMX_I2C_IFDR);
--
1.8.4
^ permalink raw reply related [flat|nested] 33+ messages in thread
* [PATCH v3 2/2] Documentation:add DMA support for freescale i2c driver
@ 2014-03-13 1:47 ` Yuan Yao
0 siblings, 0 replies; 33+ messages in thread
From: Yuan Yao @ 2014-03-13 1:47 UTC (permalink / raw)
To: wsa, marex
Cc: mark.rutland, shawn.guo, linux-kernel, linux-arm-kernel, linux-i2c
Add i2c dts node properties for eDMA support, them depend on the eDMA driver.
Signed-off-by: Yuan Yao <yao.yuan@freescale.com>
---
Documentation/devicetree/bindings/i2c/i2c-imx.txt | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/Documentation/devicetree/bindings/i2c/i2c-imx.txt b/Documentation/devicetree/bindings/i2c/i2c-imx.txt
index 4a8513e..52d37fd 100644
--- a/Documentation/devicetree/bindings/i2c/i2c-imx.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c-imx.txt
@@ -11,6 +11,8 @@ Required properties:
Optional properties:
- clock-frequency : Constains desired I2C/HS-I2C bus clock frequency in Hz.
The absence of the propoerty indicates the default frequency 100 kHz.
+- dmas: A list of two dma specifiers, one for each entry in dma-names.
+- dma-names: should contain "tx" and "rx".
Examples:
@@ -26,3 +28,12 @@ i2c@70038000 { /* HS-I2C on i.MX51 */
interrupts = <64>;
clock-frequency = <400000>;
};
+
+i2c0: i2c@40066000 { /* i2c0 on vf610 */
+ compatible = "fsl,vf610-i2c";
+ reg = <0x40066000 0x1000>;
+ interrupts =<0 71 0x04>;
+ dmas = <&edma0 0 50>,
+ <&edma0 0 51>;
+ dma-names = "rx","tx";
+};
--
1.8.4
^ permalink raw reply related [flat|nested] 33+ messages in thread
* [PATCH v3 2/2] Documentation:add DMA support for freescale i2c driver
@ 2014-03-13 1:47 ` Yuan Yao
0 siblings, 0 replies; 33+ messages in thread
From: Yuan Yao @ 2014-03-13 1:47 UTC (permalink / raw)
To: wsa-z923LK4zBo2bacvFa/9K2g, marex-ynQEQJNshbs
Cc: mark.rutland-5wv7dgnIgG8, shawn.guo-QSEj5FYQhm4dnm+yROfE0A,
linux-kernel-u79uwXL29TY76Z2rM5mHXA,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
linux-i2c-u79uwXL29TY76Z2rM5mHXA
Add i2c dts node properties for eDMA support, them depend on the eDMA driver.
Signed-off-by: Yuan Yao <yao.yuan-KZfg59tc24xl57MIdRCFDg@public.gmane.org>
---
Documentation/devicetree/bindings/i2c/i2c-imx.txt | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/Documentation/devicetree/bindings/i2c/i2c-imx.txt b/Documentation/devicetree/bindings/i2c/i2c-imx.txt
index 4a8513e..52d37fd 100644
--- a/Documentation/devicetree/bindings/i2c/i2c-imx.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c-imx.txt
@@ -11,6 +11,8 @@ Required properties:
Optional properties:
- clock-frequency : Constains desired I2C/HS-I2C bus clock frequency in Hz.
The absence of the propoerty indicates the default frequency 100 kHz.
+- dmas: A list of two dma specifiers, one for each entry in dma-names.
+- dma-names: should contain "tx" and "rx".
Examples:
@@ -26,3 +28,12 @@ i2c@70038000 { /* HS-I2C on i.MX51 */
interrupts = <64>;
clock-frequency = <400000>;
};
+
+i2c0: i2c@40066000 { /* i2c0 on vf610 */
+ compatible = "fsl,vf610-i2c";
+ reg = <0x40066000 0x1000>;
+ interrupts =<0 71 0x04>;
+ dmas = <&edma0 0 50>,
+ <&edma0 0 51>;
+ dma-names = "rx","tx";
+};
--
1.8.4
^ permalink raw reply related [flat|nested] 33+ messages in thread
* [PATCH v3 2/2] Documentation:add DMA support for freescale i2c driver
@ 2014-03-13 1:47 ` Yuan Yao
0 siblings, 0 replies; 33+ messages in thread
From: Yuan Yao @ 2014-03-13 1:47 UTC (permalink / raw)
To: linux-arm-kernel
Add i2c dts node properties for eDMA support, them depend on the eDMA driver.
Signed-off-by: Yuan Yao <yao.yuan@freescale.com>
---
Documentation/devicetree/bindings/i2c/i2c-imx.txt | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/Documentation/devicetree/bindings/i2c/i2c-imx.txt b/Documentation/devicetree/bindings/i2c/i2c-imx.txt
index 4a8513e..52d37fd 100644
--- a/Documentation/devicetree/bindings/i2c/i2c-imx.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c-imx.txt
@@ -11,6 +11,8 @@ Required properties:
Optional properties:
- clock-frequency : Constains desired I2C/HS-I2C bus clock frequency in Hz.
The absence of the propoerty indicates the default frequency 100 kHz.
+- dmas: A list of two dma specifiers, one for each entry in dma-names.
+- dma-names: should contain "tx" and "rx".
Examples:
@@ -26,3 +28,12 @@ i2c at 70038000 { /* HS-I2C on i.MX51 */
interrupts = <64>;
clock-frequency = <400000>;
};
+
+i2c0: i2c at 40066000 { /* i2c0 on vf610 */
+ compatible = "fsl,vf610-i2c";
+ reg = <0x40066000 0x1000>;
+ interrupts =<0 71 0x04>;
+ dmas = <&edma0 0 50>,
+ <&edma0 0 51>;
+ dma-names = "rx","tx";
+};
--
1.8.4
^ permalink raw reply related [flat|nested] 33+ messages in thread
* Re: [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
@ 2014-03-23 3:49 ` Marek Vasut
0 siblings, 0 replies; 33+ messages in thread
From: Marek Vasut @ 2014-03-23 3:49 UTC (permalink / raw)
To: Yuan Yao
Cc: wsa, mark.rutland, shawn.guo, linux-kernel, linux-arm-kernel, linux-i2c
On Thursday, March 13, 2014 at 02:47:56 AM, Yuan Yao wrote:
> Add dma support for i2c. This function depend on DMA driver.
> You can turn on it by write both the dmas and dma-name properties in dts
> node.
>
> Signed-off-by: Yuan Yao <yao.yuan@freescale.com>
> ---
> drivers/i2c/busses/i2c-imx.c | 354
> +++++++++++++++++++++++++++++++++++++------ 1 file changed, 306
> insertions(+), 48 deletions(-)
Changelog is missing.
[...]
> +/* Functions for DMA support */
> +static int i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,
> + dma_addr_t phy_addr)
> +{
> + struct imx_i2c_dma *dma = i2c_imx->dma;
> + struct dma_slave_config dma_sconfig;
> + struct device *dev = &i2c_imx->adapter.dev;
> + int ret;
> +
> + dma->chan_tx = dma_request_slave_channel(dev, "tx");
> + if (!dma->chan_tx) {
> + dev_err(dev, "Dma tx channel request failed!\n");
DMA is written in all caps, it's an abbrev. for Direct Memory Access . Please
fix globally.
[...]
> static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg
> *msgs) {
[...]
> - /* write data */
> - for (i = 0; i < msgs->len; i++) {
> - dev_dbg(&i2c_imx->adapter.dev,
> - "<%s> write byte: B%d=0x%X\n",
> - __func__, i, msgs->buf[i]);
> - imx_i2c_write_reg(msgs->buf[i], i2c_imx, IMX_I2C_I2DR);
> + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
> + temp |= I2CR_DMAEN;
> + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
> +
> + /* write slave address */
> + imx_i2c_write_reg(msgs->addr << 1, i2c_imx, IMX_I2C_I2DR);
> + result = wait_for_completion_interruptible_timeout(
> + &i2c_imx->dma->cmd_complete,
> + msecs_to_jiffies(IMX_I2C_DMA_TIMEOUT));
> + if (result <= 0) {
> + dmaengine_terminate_all(dma->chan_using);
> + if (result)
> + return result;
> + else
> + return -ETIMEDOUT;
> + }
> +
> + /* waiting for Transfer complete. */
> + while (timeout--) {
> + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
> + if (temp & I2SR_ICF)
> + break;
> + udelay(10);
> + }
Do you ever check if this really timed out and handle such case at all ? I don't
see it , but I might be wrong ...
> + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
> + temp &= ~I2CR_DMAEN;
> + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
> +
> + /* write the last byte */
> + imx_i2c_write_reg(msgs->buf[msgs->len-1],
> + i2c_imx, IMX_I2C_I2DR);
> result = i2c_imx_trx_complete(i2c_imx);
> if (result)
> return result;
> +
> result = i2c_imx_acked(i2c_imx);
> if (result)
> return result;
> + } else {
> + /* write slave address */
> + imx_i2c_write_reg(msgs->addr << 1, i2c_imx, IMX_I2C_I2DR);
> + result = i2c_imx_trx_complete(i2c_imx);
> + if (result)
> + return result;
> +
> + result = i2c_imx_acked(i2c_imx);
> + if (result)
> + return result;
> +
> + dev_dbg(&i2c_imx->adapter.dev, "<%s> write data\n", __func__);
> +
> + /* write data */
> + for (i = 0; i < msgs->len; i++) {
> + dev_dbg(&i2c_imx->adapter.dev,
> + "<%s> write byte: B%d=0x%X\n",
> + __func__, i, msgs->buf[i]);
Can you not just have a variable $dev here and avoid having such a long noodle
in the dev_dbg() call ?
> + imx_i2c_write_reg(msgs->buf[i], i2c_imx, IMX_I2C_I2DR);
> + result = i2c_imx_trx_complete(i2c_imx);
> + if (result)
> + return result;
> + result = i2c_imx_acked(i2c_imx);
> + if (result)
> + return result;
> + }
> }
> return 0;
> }
[...]
> + /* waiting for Transfer complete. */
> + while (timeout--) {
> + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
> + if (temp & I2SR_ICF)
> + break;
> + udelay(10);
> + }
Timeout handling here as well ...
[...]
> @@ -696,6 +936,21 @@ static int i2c_imx_probe(struct platform_device *pdev)
> i2c_imx->adapter.name);
> dev_info(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n");
>
> + /* Init DMA config if support*/
> + i2c_imx->dma = devm_kzalloc(&pdev->dev, sizeof(struct imx_i2c_dma),
> + GFP_KERNEL);
> + if (!i2c_imx->dma) {
> + dev_info(&pdev->dev,
> + "can't allocate dma struct faild use dma.\n");
Or just have $dev variable and you won't have to break the line at all ...
> + i2c_imx->use_dma = false;
> + } else if (i2c_imx_dma_request(i2c_imx, (dma_addr_t)phy_addr)) {
> + dev_info(&pdev->dev,
> + "can't request dma chan, faild use dma.\n");
> + i2c_imx->use_dma = false;
> + } else {
> + i2c_imx->use_dma = true;
> + }
Can you not just check if i2c_imx->dma is valid pointer or NULL pointer ? Then
you won't need a separate variable, for this purpose ... right ?
[...]
^ permalink raw reply [flat|nested] 33+ messages in thread
* Re: [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
@ 2014-03-23 3:49 ` Marek Vasut
0 siblings, 0 replies; 33+ messages in thread
From: Marek Vasut @ 2014-03-23 3:49 UTC (permalink / raw)
To: Yuan Yao
Cc: wsa-z923LK4zBo2bacvFa/9K2g, mark.rutland-5wv7dgnIgG8,
shawn.guo-QSEj5FYQhm4dnm+yROfE0A,
linux-kernel-u79uwXL29TY76Z2rM5mHXA,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
linux-i2c-u79uwXL29TY76Z2rM5mHXA
On Thursday, March 13, 2014 at 02:47:56 AM, Yuan Yao wrote:
> Add dma support for i2c. This function depend on DMA driver.
> You can turn on it by write both the dmas and dma-name properties in dts
> node.
>
> Signed-off-by: Yuan Yao <yao.yuan-KZfg59tc24xl57MIdRCFDg@public.gmane.org>
> ---
> drivers/i2c/busses/i2c-imx.c | 354
> +++++++++++++++++++++++++++++++++++++------ 1 file changed, 306
> insertions(+), 48 deletions(-)
Changelog is missing.
[...]
> +/* Functions for DMA support */
> +static int i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,
> + dma_addr_t phy_addr)
> +{
> + struct imx_i2c_dma *dma = i2c_imx->dma;
> + struct dma_slave_config dma_sconfig;
> + struct device *dev = &i2c_imx->adapter.dev;
> + int ret;
> +
> + dma->chan_tx = dma_request_slave_channel(dev, "tx");
> + if (!dma->chan_tx) {
> + dev_err(dev, "Dma tx channel request failed!\n");
DMA is written in all caps, it's an abbrev. for Direct Memory Access . Please
fix globally.
[...]
> static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg
> *msgs) {
[...]
> - /* write data */
> - for (i = 0; i < msgs->len; i++) {
> - dev_dbg(&i2c_imx->adapter.dev,
> - "<%s> write byte: B%d=0x%X\n",
> - __func__, i, msgs->buf[i]);
> - imx_i2c_write_reg(msgs->buf[i], i2c_imx, IMX_I2C_I2DR);
> + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
> + temp |= I2CR_DMAEN;
> + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
> +
> + /* write slave address */
> + imx_i2c_write_reg(msgs->addr << 1, i2c_imx, IMX_I2C_I2DR);
> + result = wait_for_completion_interruptible_timeout(
> + &i2c_imx->dma->cmd_complete,
> + msecs_to_jiffies(IMX_I2C_DMA_TIMEOUT));
> + if (result <= 0) {
> + dmaengine_terminate_all(dma->chan_using);
> + if (result)
> + return result;
> + else
> + return -ETIMEDOUT;
> + }
> +
> + /* waiting for Transfer complete. */
> + while (timeout--) {
> + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
> + if (temp & I2SR_ICF)
> + break;
> + udelay(10);
> + }
Do you ever check if this really timed out and handle such case at all ? I don't
see it , but I might be wrong ...
> + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
> + temp &= ~I2CR_DMAEN;
> + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
> +
> + /* write the last byte */
> + imx_i2c_write_reg(msgs->buf[msgs->len-1],
> + i2c_imx, IMX_I2C_I2DR);
> result = i2c_imx_trx_complete(i2c_imx);
> if (result)
> return result;
> +
> result = i2c_imx_acked(i2c_imx);
> if (result)
> return result;
> + } else {
> + /* write slave address */
> + imx_i2c_write_reg(msgs->addr << 1, i2c_imx, IMX_I2C_I2DR);
> + result = i2c_imx_trx_complete(i2c_imx);
> + if (result)
> + return result;
> +
> + result = i2c_imx_acked(i2c_imx);
> + if (result)
> + return result;
> +
> + dev_dbg(&i2c_imx->adapter.dev, "<%s> write data\n", __func__);
> +
> + /* write data */
> + for (i = 0; i < msgs->len; i++) {
> + dev_dbg(&i2c_imx->adapter.dev,
> + "<%s> write byte: B%d=0x%X\n",
> + __func__, i, msgs->buf[i]);
Can you not just have a variable $dev here and avoid having such a long noodle
in the dev_dbg() call ?
> + imx_i2c_write_reg(msgs->buf[i], i2c_imx, IMX_I2C_I2DR);
> + result = i2c_imx_trx_complete(i2c_imx);
> + if (result)
> + return result;
> + result = i2c_imx_acked(i2c_imx);
> + if (result)
> + return result;
> + }
> }
> return 0;
> }
[...]
> + /* waiting for Transfer complete. */
> + while (timeout--) {
> + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
> + if (temp & I2SR_ICF)
> + break;
> + udelay(10);
> + }
Timeout handling here as well ...
[...]
> @@ -696,6 +936,21 @@ static int i2c_imx_probe(struct platform_device *pdev)
> i2c_imx->adapter.name);
> dev_info(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n");
>
> + /* Init DMA config if support*/
> + i2c_imx->dma = devm_kzalloc(&pdev->dev, sizeof(struct imx_i2c_dma),
> + GFP_KERNEL);
> + if (!i2c_imx->dma) {
> + dev_info(&pdev->dev,
> + "can't allocate dma struct faild use dma.\n");
Or just have $dev variable and you won't have to break the line at all ...
> + i2c_imx->use_dma = false;
> + } else if (i2c_imx_dma_request(i2c_imx, (dma_addr_t)phy_addr)) {
> + dev_info(&pdev->dev,
> + "can't request dma chan, faild use dma.\n");
> + i2c_imx->use_dma = false;
> + } else {
> + i2c_imx->use_dma = true;
> + }
Can you not just check if i2c_imx->dma is valid pointer or NULL pointer ? Then
you won't need a separate variable, for this purpose ... right ?
[...]
^ permalink raw reply [flat|nested] 33+ messages in thread
* [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
@ 2014-03-23 3:49 ` Marek Vasut
0 siblings, 0 replies; 33+ messages in thread
From: Marek Vasut @ 2014-03-23 3:49 UTC (permalink / raw)
To: linux-arm-kernel
On Thursday, March 13, 2014 at 02:47:56 AM, Yuan Yao wrote:
> Add dma support for i2c. This function depend on DMA driver.
> You can turn on it by write both the dmas and dma-name properties in dts
> node.
>
> Signed-off-by: Yuan Yao <yao.yuan@freescale.com>
> ---
> drivers/i2c/busses/i2c-imx.c | 354
> +++++++++++++++++++++++++++++++++++++------ 1 file changed, 306
> insertions(+), 48 deletions(-)
Changelog is missing.
[...]
> +/* Functions for DMA support */
> +static int i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,
> + dma_addr_t phy_addr)
> +{
> + struct imx_i2c_dma *dma = i2c_imx->dma;
> + struct dma_slave_config dma_sconfig;
> + struct device *dev = &i2c_imx->adapter.dev;
> + int ret;
> +
> + dma->chan_tx = dma_request_slave_channel(dev, "tx");
> + if (!dma->chan_tx) {
> + dev_err(dev, "Dma tx channel request failed!\n");
DMA is written in all caps, it's an abbrev. for Direct Memory Access . Please
fix globally.
[...]
> static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct i2c_msg
> *msgs) {
[...]
> - /* write data */
> - for (i = 0; i < msgs->len; i++) {
> - dev_dbg(&i2c_imx->adapter.dev,
> - "<%s> write byte: B%d=0x%X\n",
> - __func__, i, msgs->buf[i]);
> - imx_i2c_write_reg(msgs->buf[i], i2c_imx, IMX_I2C_I2DR);
> + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
> + temp |= I2CR_DMAEN;
> + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
> +
> + /* write slave address */
> + imx_i2c_write_reg(msgs->addr << 1, i2c_imx, IMX_I2C_I2DR);
> + result = wait_for_completion_interruptible_timeout(
> + &i2c_imx->dma->cmd_complete,
> + msecs_to_jiffies(IMX_I2C_DMA_TIMEOUT));
> + if (result <= 0) {
> + dmaengine_terminate_all(dma->chan_using);
> + if (result)
> + return result;
> + else
> + return -ETIMEDOUT;
> + }
> +
> + /* waiting for Transfer complete. */
> + while (timeout--) {
> + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
> + if (temp & I2SR_ICF)
> + break;
> + udelay(10);
> + }
Do you ever check if this really timed out and handle such case at all ? I don't
see it , but I might be wrong ...
> + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
> + temp &= ~I2CR_DMAEN;
> + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
> +
> + /* write the last byte */
> + imx_i2c_write_reg(msgs->buf[msgs->len-1],
> + i2c_imx, IMX_I2C_I2DR);
> result = i2c_imx_trx_complete(i2c_imx);
> if (result)
> return result;
> +
> result = i2c_imx_acked(i2c_imx);
> if (result)
> return result;
> + } else {
> + /* write slave address */
> + imx_i2c_write_reg(msgs->addr << 1, i2c_imx, IMX_I2C_I2DR);
> + result = i2c_imx_trx_complete(i2c_imx);
> + if (result)
> + return result;
> +
> + result = i2c_imx_acked(i2c_imx);
> + if (result)
> + return result;
> +
> + dev_dbg(&i2c_imx->adapter.dev, "<%s> write data\n", __func__);
> +
> + /* write data */
> + for (i = 0; i < msgs->len; i++) {
> + dev_dbg(&i2c_imx->adapter.dev,
> + "<%s> write byte: B%d=0x%X\n",
> + __func__, i, msgs->buf[i]);
Can you not just have a variable $dev here and avoid having such a long noodle
in the dev_dbg() call ?
> + imx_i2c_write_reg(msgs->buf[i], i2c_imx, IMX_I2C_I2DR);
> + result = i2c_imx_trx_complete(i2c_imx);
> + if (result)
> + return result;
> + result = i2c_imx_acked(i2c_imx);
> + if (result)
> + return result;
> + }
> }
> return 0;
> }
[...]
> + /* waiting for Transfer complete. */
> + while (timeout--) {
> + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
> + if (temp & I2SR_ICF)
> + break;
> + udelay(10);
> + }
Timeout handling here as well ...
[...]
> @@ -696,6 +936,21 @@ static int i2c_imx_probe(struct platform_device *pdev)
> i2c_imx->adapter.name);
> dev_info(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n");
>
> + /* Init DMA config if support*/
> + i2c_imx->dma = devm_kzalloc(&pdev->dev, sizeof(struct imx_i2c_dma),
> + GFP_KERNEL);
> + if (!i2c_imx->dma) {
> + dev_info(&pdev->dev,
> + "can't allocate dma struct faild use dma.\n");
Or just have $dev variable and you won't have to break the line at all ...
> + i2c_imx->use_dma = false;
> + } else if (i2c_imx_dma_request(i2c_imx, (dma_addr_t)phy_addr)) {
> + dev_info(&pdev->dev,
> + "can't request dma chan, faild use dma.\n");
> + i2c_imx->use_dma = false;
> + } else {
> + i2c_imx->use_dma = true;
> + }
Can you not just check if i2c_imx->dma is valid pointer or NULL pointer ? Then
you won't need a separate variable, for this purpose ... right ?
[...]
^ permalink raw reply [flat|nested] 33+ messages in thread
* RE: [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
2014-03-23 3:49 ` Marek Vasut
(?)
@ 2014-03-26 3:08 ` Yao Yuan
-1 siblings, 0 replies; 33+ messages in thread
From: Yao Yuan @ 2014-03-26 3:08 UTC (permalink / raw)
To: Marek Vasut
Cc: wsa, mark.rutland, shawn.guo, linux-kernel, linux-arm-kernel, linux-i2c
[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset="utf-8", Size: 5609 bytes --]
On Sunday, March 23, 2014 @ 11:50:00 AM, Marek Vasut wrote:
> On Thursday, March 13, 2014 at 02:47:56 AM, Yuan Yao wrote:
> > Add dma support for i2c. This function depend on DMA driver.
> > You can turn on it by write both the dmas and dma-name properties in
> > dts node.
> >
> > Signed-off-by: Yuan Yao <yao.yuan@freescale.com>
> > ---
> > drivers/i2c/busses/i2c-imx.c | 354
> > +++++++++++++++++++++++++++++++++++++------ 1 file changed, 306
> > insertions(+), 48 deletions(-)
>
> Changelog is missing.
Sorry for this, Maybe the changelog is in the junk box. It's named "[PATCH v3 0/2] i2c: add DMA support for freescale i2c driver".
> [...]
>
> > +/* Functions for DMA support */
> > +static int i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,
> > + dma_addr_t phy_addr)
> > +{
> > + struct imx_i2c_dma *dma = i2c_imx->dma;
> > + struct dma_slave_config dma_sconfig;
> > + struct device *dev = &i2c_imx->adapter.dev;
> > + int ret;
> > +
> > + dma->chan_tx = dma_request_slave_channel(dev, "tx");
> > + if (!dma->chan_tx) {
> > + dev_err(dev, "Dma tx channel request failed!\n");
>
> DMA is written in all caps, it's an abbrev. for Direct Memory Access .
> Please fix globally.
>
Ok, I will fix it globally.
> [...]
>
> > static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct
> > i2c_msg
> > *msgs) {
>
> [...]
>
> > - /* write data */
> > - for (i = 0; i < msgs->len; i++) {
> > - dev_dbg(&i2c_imx->adapter.dev,
> > - "<%s> write byte: B%d=0x%X\n",
> > - __func__, i, msgs->buf[i]);
> > - imx_i2c_write_reg(msgs->buf[i], i2c_imx, IMX_I2C_I2DR);
> > + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
> > + temp |= I2CR_DMAEN;
> > + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
> > +
> > + /* write slave address */
> > + imx_i2c_write_reg(msgs->addr << 1, i2c_imx, IMX_I2C_I2DR);
> > + result = wait_for_completion_interruptible_timeout(
> > + &i2c_imx->dma->cmd_complete,
> > + msecs_to_jiffies(IMX_I2C_DMA_TIMEOUT));
> > + if (result <= 0) {
> > + dmaengine_terminate_all(dma->chan_using);
> > + if (result)
> > + return result;
> > + else
> > + return -ETIMEDOUT;
> > + }
> > +
> > + /* waiting for Transfer complete. */
> > + while (timeout--) {
> > + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
> > + if (temp & I2SR_ICF)
> > + break;
> > + udelay(10);
> > + }
>
> Do you ever check if this really timed out and handle such case at all ?
> I don't see it , but I might be wrong ...
>
Oh, It's a bug, Thank you very much.
> > + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
> > + temp &= ~I2CR_DMAEN;
> > + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
> > +
> > + /* write the last byte */
> > + imx_i2c_write_reg(msgs->buf[msgs->len-1],
> > + i2c_imx, IMX_I2C_I2DR);
> > result = i2c_imx_trx_complete(i2c_imx);
> > if (result)
> > return result;
> > +
> > result = i2c_imx_acked(i2c_imx);
> > if (result)
> > return result;
> > + } else {
> > + /* write slave address */
> > + imx_i2c_write_reg(msgs->addr << 1, i2c_imx, IMX_I2C_I2DR);
> > + result = i2c_imx_trx_complete(i2c_imx);
> > + if (result)
> > + return result;
> > +
> > + result = i2c_imx_acked(i2c_imx);
> > + if (result)
> > + return result;
> > +
> > + dev_dbg(&i2c_imx->adapter.dev, "<%s> write data\n", __func__);
> > +
> > + /* write data */
> > + for (i = 0; i < msgs->len; i++) {
> > + dev_dbg(&i2c_imx->adapter.dev,
> > + "<%s> write byte: B%d=0x%X\n",
> > + __func__, i, msgs->buf[i]);
>
> Can you not just have a variable $dev here and avoid having such a long
> noodle in the dev_dbg() call ?
>
Ok, And I don't think the dev_dbg() is very helpful here now.
> > + imx_i2c_write_reg(msgs->buf[i], i2c_imx, IMX_I2C_I2DR);
> > + result = i2c_imx_trx_complete(i2c_imx);
> > + if (result)
> > + return result;
> > + result = i2c_imx_acked(i2c_imx);
> > + if (result)
> > + return result;
> > + }
> > }
> > return 0;
> > }
> [...]
>
> > + /* waiting for Transfer complete. */
> > + while (timeout--) {
> > + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
> > + if (temp & I2SR_ICF)
> > + break;
> > + udelay(10);
> > + }
>
> Timeout handling here as well ...
>
> [...]
>
> > @@ -696,6 +936,21 @@ static int i2c_imx_probe(struct platform_device
> *pdev)
> > i2c_imx->adapter.name);
> > dev_info(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n");
> >
> > + /* Init DMA config if support*/
> > + i2c_imx->dma = devm_kzalloc(&pdev->dev, sizeof(struct imx_i2c_dma),
> > + GFP_KERNEL);
> > + if (!i2c_imx->dma) {
> > + dev_info(&pdev->dev,
> > + "can't allocate dma struct faild use dma.\n");
>
> Or just have $dev variable and you won't have to break the line at all ...
>
> > + i2c_imx->use_dma = false;
> > + } else if (i2c_imx_dma_request(i2c_imx, (dma_addr_t)phy_addr)) {
> > + dev_info(&pdev->dev,
> > + "can't request dma chan, faild use dma.\n");
> > + i2c_imx->use_dma = false;
> > + } else {
> > + i2c_imx->use_dma = true;
> > + }
>
> Can you not just check if i2c_imx->dma is valid pointer or NULL pointer ?
> Then you won't need a separate variable, for this purpose ... right ?
Sorry and I think what I know is just to check whether it is NULL.
Then for the second question, maybe there are some other ways, But I think it is more tidy and easier
understanding for using a separate variable, for this purpose.
> [...]
>
Best regards,
Yuan Yao
ÿôèº{.nÇ+·®+%Ëÿ±éݶ\x17¥wÿº{.nÇ+·¥{±þG«éÿ{ayº\x1dÊÚë,j\a¢f£¢·hïêÿêçz_è®\x03(éÝ¢j"ú\x1a¶^[m§ÿÿ¾\a«þG«éÿ¢¸?¨èÚ&£ø§~á¶iOæ¬z·vØ^\x14\x04\x1a¶^[m§ÿÿÃ\fÿ¶ìÿ¢¸?I¥
^ permalink raw reply [flat|nested] 33+ messages in thread
* RE: [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
@ 2014-03-26 3:08 ` Yao Yuan
0 siblings, 0 replies; 33+ messages in thread
From: Yao Yuan @ 2014-03-26 3:08 UTC (permalink / raw)
To: Marek Vasut
Cc: mark.rutland, wsa, linux-kernel, linux-i2c, shawn.guo, linux-arm-kernel
On Sunday, March 23, 2014 @ 11:50:00 AM, Marek Vasut wrote:
> On Thursday, March 13, 2014 at 02:47:56 AM, Yuan Yao wrote:
> > Add dma support for i2c. This function depend on DMA driver.
> > You can turn on it by write both the dmas and dma-name properties in
> > dts node.
> >
> > Signed-off-by: Yuan Yao <yao.yuan@freescale.com>
> > ---
> > drivers/i2c/busses/i2c-imx.c | 354
> > +++++++++++++++++++++++++++++++++++++------ 1 file changed, 306
> > insertions(+), 48 deletions(-)
>
> Changelog is missing.
Sorry for this, Maybe the changelog is in the junk box. It's named "[PATCH v3 0/2] i2c: add DMA support for freescale i2c driver".
> [...]
>
> > +/* Functions for DMA support */
> > +static int i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,
> > + dma_addr_t phy_addr)
> > +{
> > + struct imx_i2c_dma *dma = i2c_imx->dma;
> > + struct dma_slave_config dma_sconfig;
> > + struct device *dev = &i2c_imx->adapter.dev;
> > + int ret;
> > +
> > + dma->chan_tx = dma_request_slave_channel(dev, "tx");
> > + if (!dma->chan_tx) {
> > + dev_err(dev, "Dma tx channel request failed!\n");
>
> DMA is written in all caps, it's an abbrev. for Direct Memory Access .
> Please fix globally.
>
Ok, I will fix it globally.
> [...]
>
> > static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct
> > i2c_msg
> > *msgs) {
>
> [...]
>
> > - /* write data */
> > - for (i = 0; i < msgs->len; i++) {
> > - dev_dbg(&i2c_imx->adapter.dev,
> > - "<%s> write byte: B%d=0x%X\n",
> > - __func__, i, msgs->buf[i]);
> > - imx_i2c_write_reg(msgs->buf[i], i2c_imx, IMX_I2C_I2DR);
> > + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
> > + temp |= I2CR_DMAEN;
> > + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
> > +
> > + /* write slave address */
> > + imx_i2c_write_reg(msgs->addr << 1, i2c_imx, IMX_I2C_I2DR);
> > + result = wait_for_completion_interruptible_timeout(
> > + &i2c_imx->dma->cmd_complete,
> > + msecs_to_jiffies(IMX_I2C_DMA_TIMEOUT));
> > + if (result <= 0) {
> > + dmaengine_terminate_all(dma->chan_using);
> > + if (result)
> > + return result;
> > + else
> > + return -ETIMEDOUT;
> > + }
> > +
> > + /* waiting for Transfer complete. */
> > + while (timeout--) {
> > + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
> > + if (temp & I2SR_ICF)
> > + break;
> > + udelay(10);
> > + }
>
> Do you ever check if this really timed out and handle such case at all ?
> I don't see it , but I might be wrong ...
>
Oh, It's a bug, Thank you very much.
> > + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
> > + temp &= ~I2CR_DMAEN;
> > + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
> > +
> > + /* write the last byte */
> > + imx_i2c_write_reg(msgs->buf[msgs->len-1],
> > + i2c_imx, IMX_I2C_I2DR);
> > result = i2c_imx_trx_complete(i2c_imx);
> > if (result)
> > return result;
> > +
> > result = i2c_imx_acked(i2c_imx);
> > if (result)
> > return result;
> > + } else {
> > + /* write slave address */
> > + imx_i2c_write_reg(msgs->addr << 1, i2c_imx, IMX_I2C_I2DR);
> > + result = i2c_imx_trx_complete(i2c_imx);
> > + if (result)
> > + return result;
> > +
> > + result = i2c_imx_acked(i2c_imx);
> > + if (result)
> > + return result;
> > +
> > + dev_dbg(&i2c_imx->adapter.dev, "<%s> write data\n", __func__);
> > +
> > + /* write data */
> > + for (i = 0; i < msgs->len; i++) {
> > + dev_dbg(&i2c_imx->adapter.dev,
> > + "<%s> write byte: B%d=0x%X\n",
> > + __func__, i, msgs->buf[i]);
>
> Can you not just have a variable $dev here and avoid having such a long
> noodle in the dev_dbg() call ?
>
Ok, And I don't think the dev_dbg() is very helpful here now.
> > + imx_i2c_write_reg(msgs->buf[i], i2c_imx, IMX_I2C_I2DR);
> > + result = i2c_imx_trx_complete(i2c_imx);
> > + if (result)
> > + return result;
> > + result = i2c_imx_acked(i2c_imx);
> > + if (result)
> > + return result;
> > + }
> > }
> > return 0;
> > }
> [...]
>
> > + /* waiting for Transfer complete. */
> > + while (timeout--) {
> > + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
> > + if (temp & I2SR_ICF)
> > + break;
> > + udelay(10);
> > + }
>
> Timeout handling here as well ...
>
> [...]
>
> > @@ -696,6 +936,21 @@ static int i2c_imx_probe(struct platform_device
> *pdev)
> > i2c_imx->adapter.name);
> > dev_info(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n");
> >
> > + /* Init DMA config if support*/
> > + i2c_imx->dma = devm_kzalloc(&pdev->dev, sizeof(struct imx_i2c_dma),
> > + GFP_KERNEL);
> > + if (!i2c_imx->dma) {
> > + dev_info(&pdev->dev,
> > + "can't allocate dma struct faild use dma.\n");
>
> Or just have $dev variable and you won't have to break the line at all ...
>
> > + i2c_imx->use_dma = false;
> > + } else if (i2c_imx_dma_request(i2c_imx, (dma_addr_t)phy_addr)) {
> > + dev_info(&pdev->dev,
> > + "can't request dma chan, faild use dma.\n");
> > + i2c_imx->use_dma = false;
> > + } else {
> > + i2c_imx->use_dma = true;
> > + }
>
> Can you not just check if i2c_imx->dma is valid pointer or NULL pointer ?
> Then you won't need a separate variable, for this purpose ... right ?
Sorry and I think what I know is just to check whether it is NULL.
Then for the second question, maybe there are some other ways, But I think it is more tidy and easier
understanding for using a separate variable, for this purpose.
> [...]
>
Best regards,
Yuan Yao
^ permalink raw reply [flat|nested] 33+ messages in thread
* [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
@ 2014-03-26 3:08 ` Yao Yuan
0 siblings, 0 replies; 33+ messages in thread
From: Yao Yuan @ 2014-03-26 3:08 UTC (permalink / raw)
To: linux-arm-kernel
On Sunday, March 23, 2014 @ 11:50:00 AM, Marek Vasut wrote:
> On Thursday, March 13, 2014 at 02:47:56 AM, Yuan Yao wrote:
> > Add dma support for i2c. This function depend on DMA driver.
> > You can turn on it by write both the dmas and dma-name properties in
> > dts node.
> >
> > Signed-off-by: Yuan Yao <yao.yuan@freescale.com>
> > ---
> > drivers/i2c/busses/i2c-imx.c | 354
> > +++++++++++++++++++++++++++++++++++++------ 1 file changed, 306
> > insertions(+), 48 deletions(-)
>
> Changelog is missing.
Sorry for this, Maybe the changelog is in the junk box. It's named "[PATCH v3 0/2] i2c: add DMA support for freescale i2c driver".
> [...]
>
> > +/* Functions for DMA support */
> > +static int i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,
> > + dma_addr_t phy_addr)
> > +{
> > + struct imx_i2c_dma *dma = i2c_imx->dma;
> > + struct dma_slave_config dma_sconfig;
> > + struct device *dev = &i2c_imx->adapter.dev;
> > + int ret;
> > +
> > + dma->chan_tx = dma_request_slave_channel(dev, "tx");
> > + if (!dma->chan_tx) {
> > + dev_err(dev, "Dma tx channel request failed!\n");
>
> DMA is written in all caps, it's an abbrev. for Direct Memory Access .
> Please fix globally.
>
Ok, I will fix it globally.
> [...]
>
> > static int i2c_imx_write(struct imx_i2c_struct *i2c_imx, struct
> > i2c_msg
> > *msgs) {
>
> [...]
>
> > - /* write data */
> > - for (i = 0; i < msgs->len; i++) {
> > - dev_dbg(&i2c_imx->adapter.dev,
> > - "<%s> write byte: B%d=0x%X\n",
> > - __func__, i, msgs->buf[i]);
> > - imx_i2c_write_reg(msgs->buf[i], i2c_imx, IMX_I2C_I2DR);
> > + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
> > + temp |= I2CR_DMAEN;
> > + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
> > +
> > + /* write slave address */
> > + imx_i2c_write_reg(msgs->addr << 1, i2c_imx, IMX_I2C_I2DR);
> > + result = wait_for_completion_interruptible_timeout(
> > + &i2c_imx->dma->cmd_complete,
> > + msecs_to_jiffies(IMX_I2C_DMA_TIMEOUT));
> > + if (result <= 0) {
> > + dmaengine_terminate_all(dma->chan_using);
> > + if (result)
> > + return result;
> > + else
> > + return -ETIMEDOUT;
> > + }
> > +
> > + /* waiting for Transfer complete. */
> > + while (timeout--) {
> > + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
> > + if (temp & I2SR_ICF)
> > + break;
> > + udelay(10);
> > + }
>
> Do you ever check if this really timed out and handle such case at all ?
> I don't see it , but I might be wrong ...
>
Oh, It's a bug, Thank you very much.
> > + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
> > + temp &= ~I2CR_DMAEN;
> > + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
> > +
> > + /* write the last byte */
> > + imx_i2c_write_reg(msgs->buf[msgs->len-1],
> > + i2c_imx, IMX_I2C_I2DR);
> > result = i2c_imx_trx_complete(i2c_imx);
> > if (result)
> > return result;
> > +
> > result = i2c_imx_acked(i2c_imx);
> > if (result)
> > return result;
> > + } else {
> > + /* write slave address */
> > + imx_i2c_write_reg(msgs->addr << 1, i2c_imx, IMX_I2C_I2DR);
> > + result = i2c_imx_trx_complete(i2c_imx);
> > + if (result)
> > + return result;
> > +
> > + result = i2c_imx_acked(i2c_imx);
> > + if (result)
> > + return result;
> > +
> > + dev_dbg(&i2c_imx->adapter.dev, "<%s> write data\n", __func__);
> > +
> > + /* write data */
> > + for (i = 0; i < msgs->len; i++) {
> > + dev_dbg(&i2c_imx->adapter.dev,
> > + "<%s> write byte: B%d=0x%X\n",
> > + __func__, i, msgs->buf[i]);
>
> Can you not just have a variable $dev here and avoid having such a long
> noodle in the dev_dbg() call ?
>
Ok, And I don't think the dev_dbg() is very helpful here now.
> > + imx_i2c_write_reg(msgs->buf[i], i2c_imx, IMX_I2C_I2DR);
> > + result = i2c_imx_trx_complete(i2c_imx);
> > + if (result)
> > + return result;
> > + result = i2c_imx_acked(i2c_imx);
> > + if (result)
> > + return result;
> > + }
> > }
> > return 0;
> > }
> [...]
>
> > + /* waiting for Transfer complete. */
> > + while (timeout--) {
> > + temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
> > + if (temp & I2SR_ICF)
> > + break;
> > + udelay(10);
> > + }
>
> Timeout handling here as well ...
>
> [...]
>
> > @@ -696,6 +936,21 @@ static int i2c_imx_probe(struct platform_device
> *pdev)
> > i2c_imx->adapter.name);
> > dev_info(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n");
> >
> > + /* Init DMA config if support*/
> > + i2c_imx->dma = devm_kzalloc(&pdev->dev, sizeof(struct imx_i2c_dma),
> > + GFP_KERNEL);
> > + if (!i2c_imx->dma) {
> > + dev_info(&pdev->dev,
> > + "can't allocate dma struct faild use dma.\n");
>
> Or just have $dev variable and you won't have to break the line at all ...
>
> > + i2c_imx->use_dma = false;
> > + } else if (i2c_imx_dma_request(i2c_imx, (dma_addr_t)phy_addr)) {
> > + dev_info(&pdev->dev,
> > + "can't request dma chan, faild use dma.\n");
> > + i2c_imx->use_dma = false;
> > + } else {
> > + i2c_imx->use_dma = true;
> > + }
>
> Can you not just check if i2c_imx->dma is valid pointer or NULL pointer ?
> Then you won't need a separate variable, for this purpose ... right ?
Sorry and I think what I know is just to check whether it is NULL.
Then for the second question, maybe there are some other ways, But I think it is more tidy and easier
understanding for using a separate variable, for this purpose.
> [...]
>
Best regards,
Yuan Yao
^ permalink raw reply [flat|nested] 33+ messages in thread
* Re: [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
2014-03-26 3:08 ` Yao Yuan
(?)
@ 2014-03-26 3:42 ` Marek Vasut
-1 siblings, 0 replies; 33+ messages in thread
From: Marek Vasut @ 2014-03-26 3:42 UTC (permalink / raw)
To: Yao Yuan
Cc: wsa, mark.rutland, shawn.guo, linux-kernel, linux-arm-kernel, linux-i2c
On Wednesday, March 26, 2014 at 04:08:27 AM, Yao Yuan wrote:
[...]
> > > + i2c_imx->use_dma = false;
> > > + } else if (i2c_imx_dma_request(i2c_imx, (dma_addr_t)phy_addr)) {
> > > + dev_info(&pdev->dev,
> > > + "can't request dma chan, faild use dma.\n");
> > > + i2c_imx->use_dma = false;
> > > + } else {
> > > + i2c_imx->use_dma = true;
> > > + }
> >
> > Can you not just check if i2c_imx->dma is valid pointer or NULL pointer ?
> > Then you won't need a separate variable, for this purpose ... right ?
>
> Sorry and I think what I know is just to check whether it is NULL.
> Then for the second question, maybe there are some other ways, But I think
> it is more tidy and easier understanding for using a separate variable,
> for this purpose.
You are just wasting space and duplicating data, unless I am wrong.
Best regards,
Marek Vasut
^ permalink raw reply [flat|nested] 33+ messages in thread
* Re: [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
@ 2014-03-26 3:42 ` Marek Vasut
0 siblings, 0 replies; 33+ messages in thread
From: Marek Vasut @ 2014-03-26 3:42 UTC (permalink / raw)
To: Yao Yuan
Cc: mark.rutland, wsa, linux-kernel, linux-i2c, shawn.guo, linux-arm-kernel
On Wednesday, March 26, 2014 at 04:08:27 AM, Yao Yuan wrote:
[...]
> > > + i2c_imx->use_dma = false;
> > > + } else if (i2c_imx_dma_request(i2c_imx, (dma_addr_t)phy_addr)) {
> > > + dev_info(&pdev->dev,
> > > + "can't request dma chan, faild use dma.\n");
> > > + i2c_imx->use_dma = false;
> > > + } else {
> > > + i2c_imx->use_dma = true;
> > > + }
> >
> > Can you not just check if i2c_imx->dma is valid pointer or NULL pointer ?
> > Then you won't need a separate variable, for this purpose ... right ?
>
> Sorry and I think what I know is just to check whether it is NULL.
> Then for the second question, maybe there are some other ways, But I think
> it is more tidy and easier understanding for using a separate variable,
> for this purpose.
You are just wasting space and duplicating data, unless I am wrong.
Best regards,
Marek Vasut
^ permalink raw reply [flat|nested] 33+ messages in thread
* [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
@ 2014-03-26 3:42 ` Marek Vasut
0 siblings, 0 replies; 33+ messages in thread
From: Marek Vasut @ 2014-03-26 3:42 UTC (permalink / raw)
To: linux-arm-kernel
On Wednesday, March 26, 2014 at 04:08:27 AM, Yao Yuan wrote:
[...]
> > > + i2c_imx->use_dma = false;
> > > + } else if (i2c_imx_dma_request(i2c_imx, (dma_addr_t)phy_addr)) {
> > > + dev_info(&pdev->dev,
> > > + "can't request dma chan, faild use dma.\n");
> > > + i2c_imx->use_dma = false;
> > > + } else {
> > > + i2c_imx->use_dma = true;
> > > + }
> >
> > Can you not just check if i2c_imx->dma is valid pointer or NULL pointer ?
> > Then you won't need a separate variable, for this purpose ... right ?
>
> Sorry and I think what I know is just to check whether it is NULL.
> Then for the second question, maybe there are some other ways, But I think
> it is more tidy and easier understanding for using a separate variable,
> for this purpose.
You are just wasting space and duplicating data, unless I am wrong.
Best regards,
Marek Vasut
^ permalink raw reply [flat|nested] 33+ messages in thread
* RE: [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
@ 2014-03-26 5:56 ` Yao Yuan
0 siblings, 0 replies; 33+ messages in thread
From: Yao Yuan @ 2014-03-26 5:56 UTC (permalink / raw)
To: Marek Vasut
Cc: wsa, mark.rutland, shawn.guo, linux-kernel, linux-arm-kernel, linux-i2c
[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset="utf-8", Size: 1193 bytes --]
On Wednesday, March 26, 2014 at 11:43:27 AM, Marek Vasut wrote:
> On Wednesday, March 26, 2014 at 04:08:27 AM, Yao Yuan wrote:
>
> [...]
>
> > > > + i2c_imx->use_dma = false;
> > > > + } else if (i2c_imx_dma_request(i2c_imx, (dma_addr_t)phy_addr))
> {
> > > > + dev_info(&pdev->dev,
> > > > + "can't request dma chan, faild use dma.\n");
> > > > + i2c_imx->use_dma = false;
> > > > + } else {
> > > > + i2c_imx->use_dma = true;
> > > > + }
> > >
> > > Can you not just check if i2c_imx->dma is valid pointer or NULL
> pointer ?
> > > Then you won't need a separate variable, for this purpose ... right ?
> >
> > Sorry and I think what I know is just to check whether it is NULL.
> > Then for the second question, maybe there are some other ways, But I
> > think it is more tidy and easier understanding for using a separate
> > variable, for this purpose.
>
> You are just wasting space and duplicating data, unless I am wrong.
>
Well, Do you have a better idea? Although I think it's necessary.
Best regards,
Yuan Yao
ÿôèº{.nÇ+·®+%Ëÿ±éݶ\x17¥wÿº{.nÇ+·¥{±þG«éÿ{ayº\x1dÊÚë,j\a¢f£¢·hïêÿêçz_è®\x03(éÝ¢j"ú\x1a¶^[m§ÿÿ¾\a«þG«éÿ¢¸?¨èÚ&£ø§~á¶iOæ¬z·vØ^\x14\x04\x1a¶^[m§ÿÿÃ\fÿ¶ìÿ¢¸?I¥
^ permalink raw reply [flat|nested] 33+ messages in thread
* RE: [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
@ 2014-03-26 5:56 ` Yao Yuan
0 siblings, 0 replies; 33+ messages in thread
From: Yao Yuan @ 2014-03-26 5:56 UTC (permalink / raw)
To: Marek Vasut
Cc: wsa-z923LK4zBo2bacvFa/9K2g, mark.rutland-5wv7dgnIgG8,
shawn.guo-QSEj5FYQhm4dnm+yROfE0A,
linux-kernel-u79uwXL29TY76Z2rM5mHXA,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
linux-i2c-u79uwXL29TY76Z2rM5mHXA
On Wednesday, March 26, 2014 at 11:43:27 AM, Marek Vasut wrote:
> On Wednesday, March 26, 2014 at 04:08:27 AM, Yao Yuan wrote:
>
> [...]
>
> > > > + i2c_imx->use_dma = false;
> > > > + } else if (i2c_imx_dma_request(i2c_imx, (dma_addr_t)phy_addr))
> {
> > > > + dev_info(&pdev->dev,
> > > > + "can't request dma chan, faild use dma.\n");
> > > > + i2c_imx->use_dma = false;
> > > > + } else {
> > > > + i2c_imx->use_dma = true;
> > > > + }
> > >
> > > Can you not just check if i2c_imx->dma is valid pointer or NULL
> pointer ?
> > > Then you won't need a separate variable, for this purpose ... right ?
> >
> > Sorry and I think what I know is just to check whether it is NULL.
> > Then for the second question, maybe there are some other ways, But I
> > think it is more tidy and easier understanding for using a separate
> > variable, for this purpose.
>
> You are just wasting space and duplicating data, unless I am wrong.
>
Well, Do you have a better idea? Although I think it's necessary.
Best regards,
Yuan Yao
^ permalink raw reply [flat|nested] 33+ messages in thread
* [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
@ 2014-03-26 5:56 ` Yao Yuan
0 siblings, 0 replies; 33+ messages in thread
From: Yao Yuan @ 2014-03-26 5:56 UTC (permalink / raw)
To: linux-arm-kernel
On Wednesday, March 26, 2014 at 11:43:27 AM, Marek Vasut wrote:
> On Wednesday, March 26, 2014 at 04:08:27 AM, Yao Yuan wrote:
>
> [...]
>
> > > > + i2c_imx->use_dma = false;
> > > > + } else if (i2c_imx_dma_request(i2c_imx, (dma_addr_t)phy_addr))
> {
> > > > + dev_info(&pdev->dev,
> > > > + "can't request dma chan, faild use dma.\n");
> > > > + i2c_imx->use_dma = false;
> > > > + } else {
> > > > + i2c_imx->use_dma = true;
> > > > + }
> > >
> > > Can you not just check if i2c_imx->dma is valid pointer or NULL
> pointer ?
> > > Then you won't need a separate variable, for this purpose ... right ?
> >
> > Sorry and I think what I know is just to check whether it is NULL.
> > Then for the second question, maybe there are some other ways, But I
> > think it is more tidy and easier understanding for using a separate
> > variable, for this purpose.
>
> You are just wasting space and duplicating data, unless I am wrong.
>
Well, Do you have a better idea? Although I think it's necessary.
Best regards,
Yuan Yao
^ permalink raw reply [flat|nested] 33+ messages in thread
* Re: [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
@ 2014-03-26 6:26 ` Marek Vasut
0 siblings, 0 replies; 33+ messages in thread
From: Marek Vasut @ 2014-03-26 6:26 UTC (permalink / raw)
To: Yao Yuan
Cc: wsa, mark.rutland, shawn.guo, linux-kernel, linux-arm-kernel, linux-i2c
On Wednesday, March 26, 2014 at 06:56:34 AM, Yao Yuan wrote:
> On Wednesday, March 26, 2014 at 11:43:27 AM, Marek Vasut wrote:
> > On Wednesday, March 26, 2014 at 04:08:27 AM, Yao Yuan wrote:
> >
> > [...]
> >
> > > > > + i2c_imx->use_dma = false;
> > > > > + } else if (i2c_imx_dma_request(i2c_imx, (dma_addr_t)phy_addr))
> >
> > {
> >
> > > > > + dev_info(&pdev->dev,
> > > > > + "can't request dma chan, faild use dma.
\n");
> > > > > + i2c_imx->use_dma = false;
> > > > > + } else {
> > > > > + i2c_imx->use_dma = true;
> > > > > + }
> > > >
> > > > Can you not just check if i2c_imx->dma is valid pointer or NULL
> >
> > pointer ?
> >
> > > > Then you won't need a separate variable, for this purpose ... right ?
> > >
> > > Sorry and I think what I know is just to check whether it is NULL.
> > > Then for the second question, maybe there are some other ways, But I
> > > think it is more tidy and easier understanding for using a separate
> > > variable, for this purpose.
> >
> > You are just wasting space and duplicating data, unless I am wrong.
>
> Well, Do you have a better idea? Although I think it's necessary.
I think we disconnected here, sorry. Why can you not use (i2c_imx->dma != NULL)
instead of (i2c_imx->use_dma == true) please ?
Best regards,
Marek Vasut
^ permalink raw reply [flat|nested] 33+ messages in thread
* Re: [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
@ 2014-03-26 6:26 ` Marek Vasut
0 siblings, 0 replies; 33+ messages in thread
From: Marek Vasut @ 2014-03-26 6:26 UTC (permalink / raw)
To: Yao Yuan
Cc: wsa-z923LK4zBo2bacvFa/9K2g, mark.rutland-5wv7dgnIgG8,
shawn.guo-QSEj5FYQhm4dnm+yROfE0A,
linux-kernel-u79uwXL29TY76Z2rM5mHXA,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
linux-i2c-u79uwXL29TY76Z2rM5mHXA
On Wednesday, March 26, 2014 at 06:56:34 AM, Yao Yuan wrote:
> On Wednesday, March 26, 2014 at 11:43:27 AM, Marek Vasut wrote:
> > On Wednesday, March 26, 2014 at 04:08:27 AM, Yao Yuan wrote:
> >
> > [...]
> >
> > > > > + i2c_imx->use_dma = false;
> > > > > + } else if (i2c_imx_dma_request(i2c_imx, (dma_addr_t)phy_addr))
> >
> > {
> >
> > > > > + dev_info(&pdev->dev,
> > > > > + "can't request dma chan, faild use dma.
\n");
> > > > > + i2c_imx->use_dma = false;
> > > > > + } else {
> > > > > + i2c_imx->use_dma = true;
> > > > > + }
> > > >
> > > > Can you not just check if i2c_imx->dma is valid pointer or NULL
> >
> > pointer ?
> >
> > > > Then you won't need a separate variable, for this purpose ... right ?
> > >
> > > Sorry and I think what I know is just to check whether it is NULL.
> > > Then for the second question, maybe there are some other ways, But I
> > > think it is more tidy and easier understanding for using a separate
> > > variable, for this purpose.
> >
> > You are just wasting space and duplicating data, unless I am wrong.
>
> Well, Do you have a better idea? Although I think it's necessary.
I think we disconnected here, sorry. Why can you not use (i2c_imx->dma != NULL)
instead of (i2c_imx->use_dma == true) please ?
Best regards,
Marek Vasut
^ permalink raw reply [flat|nested] 33+ messages in thread
* [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
@ 2014-03-26 6:26 ` Marek Vasut
0 siblings, 0 replies; 33+ messages in thread
From: Marek Vasut @ 2014-03-26 6:26 UTC (permalink / raw)
To: linux-arm-kernel
On Wednesday, March 26, 2014 at 06:56:34 AM, Yao Yuan wrote:
> On Wednesday, March 26, 2014 at 11:43:27 AM, Marek Vasut wrote:
> > On Wednesday, March 26, 2014 at 04:08:27 AM, Yao Yuan wrote:
> >
> > [...]
> >
> > > > > + i2c_imx->use_dma = false;
> > > > > + } else if (i2c_imx_dma_request(i2c_imx, (dma_addr_t)phy_addr))
> >
> > {
> >
> > > > > + dev_info(&pdev->dev,
> > > > > + "can't request dma chan, faild use dma.
\n");
> > > > > + i2c_imx->use_dma = false;
> > > > > + } else {
> > > > > + i2c_imx->use_dma = true;
> > > > > + }
> > > >
> > > > Can you not just check if i2c_imx->dma is valid pointer or NULL
> >
> > pointer ?
> >
> > > > Then you won't need a separate variable, for this purpose ... right ?
> > >
> > > Sorry and I think what I know is just to check whether it is NULL.
> > > Then for the second question, maybe there are some other ways, But I
> > > think it is more tidy and easier understanding for using a separate
> > > variable, for this purpose.
> >
> > You are just wasting space and duplicating data, unless I am wrong.
>
> Well, Do you have a better idea? Although I think it's necessary.
I think we disconnected here, sorry. Why can you not use (i2c_imx->dma != NULL)
instead of (i2c_imx->use_dma == true) please ?
Best regards,
Marek Vasut
^ permalink raw reply [flat|nested] 33+ messages in thread
* RE: [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
2014-03-26 6:26 ` Marek Vasut
(?)
@ 2014-03-26 7:08 ` Yao Yuan
-1 siblings, 0 replies; 33+ messages in thread
From: Yao Yuan @ 2014-03-26 7:08 UTC (permalink / raw)
To: Marek Vasut
Cc: wsa, mark.rutland, shawn.guo, linux-kernel, linux-arm-kernel, linux-i2c
[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset="utf-8", Size: 1785 bytes --]
On Wednesday, March 26, 2014 at 02:27:46 PM, Marek Vasut wrote:
> On Wednesday, March 26, 2014 at 06:56:34 AM, Yao Yuan wrote:
> > On Wednesday, March 26, 2014 at 11:43:27 AM, Marek Vasut wrote:
> > > On Wednesday, March 26, 2014 at 04:08:27 AM, Yao Yuan wrote:
> > >
> > > [...]
> > >
> > > > > > + i2c_imx->use_dma = false;
> > > > > > + } else if (i2c_imx_dma_request(i2c_imx,
> > > > > > +(dma_addr_t)phy_addr))
> > >
> > > {
> > >
> > > > > > + dev_info(&pdev->dev,
> > > > > > + "can't request dma chan, faild use dma.
> \n");
> > > > > > + i2c_imx->use_dma = false;
> > > > > > + } else {
> > > > > > + i2c_imx->use_dma = true;
> > > > > > + }
> > > > >
> > > > > Can you not just check if i2c_imx->dma is valid pointer or NULL
> > >
> > > pointer ?
> > >
> > > > > Then you won't need a separate variable, for this purpose ...
> right ?
> > > >
> > > > Sorry and I think what I know is just to check whether it is NULL.
> > > > Then for the second question, maybe there are some other ways, But
> > > > I think it is more tidy and easier understanding for using a
> > > > separate variable, for this purpose.
> > >
> > > You are just wasting space and duplicating data, unless I am wrong.
> >
> > Well, Do you have a better idea? Although I think it's necessary.
>
> I think we disconnected here, sorry. Why can you not use (i2c_imx->dma !=
> NULL) instead of (i2c_imx->use_dma == true) please ?
>
But there are two judge conditions. But only the "i2c_imx->dma", but also whether "i2c_imx_dma_request" success.
"i2c_imx->use_dma == true" be equivalent to "i2c_imx->dma != NULL && !i2c_imx_dma_request()"
ÿôèº{.nÇ+·®+%Ëÿ±éݶ\x17¥wÿº{.nÇ+·¥{±þG«éÿ{ayº\x1dÊÚë,j\a¢f£¢·hïêÿêçz_è®\x03(éÝ¢j"ú\x1a¶^[m§ÿÿ¾\a«þG«éÿ¢¸?¨èÚ&£ø§~á¶iOæ¬z·vØ^\x14\x04\x1a¶^[m§ÿÿÃ\fÿ¶ìÿ¢¸?I¥
^ permalink raw reply [flat|nested] 33+ messages in thread
* RE: [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
@ 2014-03-26 7:08 ` Yao Yuan
0 siblings, 0 replies; 33+ messages in thread
From: Yao Yuan @ 2014-03-26 7:08 UTC (permalink / raw)
To: Marek Vasut
Cc: wsa, mark.rutland, shawn.guo, linux-kernel, linux-arm-kernel, linux-i2c
On Wednesday, March 26, 2014 at 02:27:46 PM, Marek Vasut wrote:
> On Wednesday, March 26, 2014 at 06:56:34 AM, Yao Yuan wrote:
> > On Wednesday, March 26, 2014 at 11:43:27 AM, Marek Vasut wrote:
> > > On Wednesday, March 26, 2014 at 04:08:27 AM, Yao Yuan wrote:
> > >
> > > [...]
> > >
> > > > > > + i2c_imx->use_dma = false;
> > > > > > + } else if (i2c_imx_dma_request(i2c_imx,
> > > > > > +(dma_addr_t)phy_addr))
> > >
> > > {
> > >
> > > > > > + dev_info(&pdev->dev,
> > > > > > + "can't request dma chan, faild use dma.
> \n");
> > > > > > + i2c_imx->use_dma = false;
> > > > > > + } else {
> > > > > > + i2c_imx->use_dma = true;
> > > > > > + }
> > > > >
> > > > > Can you not just check if i2c_imx->dma is valid pointer or NULL
> > >
> > > pointer ?
> > >
> > > > > Then you won't need a separate variable, for this purpose ...
> right ?
> > > >
> > > > Sorry and I think what I know is just to check whether it is NULL.
> > > > Then for the second question, maybe there are some other ways, But
> > > > I think it is more tidy and easier understanding for using a
> > > > separate variable, for this purpose.
> > >
> > > You are just wasting space and duplicating data, unless I am wrong.
> >
> > Well, Do you have a better idea? Although I think it's necessary.
>
> I think we disconnected here, sorry. Why can you not use (i2c_imx->dma !=
> NULL) instead of (i2c_imx->use_dma == true) please ?
>
But there are two judge conditions. But only the "i2c_imx->dma", but also whether "i2c_imx_dma_request" success.
"i2c_imx->use_dma == true" be equivalent to "i2c_imx->dma != NULL && !i2c_imx_dma_request()"
^ permalink raw reply [flat|nested] 33+ messages in thread
* [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
@ 2014-03-26 7:08 ` Yao Yuan
0 siblings, 0 replies; 33+ messages in thread
From: Yao Yuan @ 2014-03-26 7:08 UTC (permalink / raw)
To: linux-arm-kernel
On Wednesday, March 26, 2014 at 02:27:46 PM, Marek Vasut wrote:
> On Wednesday, March 26, 2014 at 06:56:34 AM, Yao Yuan wrote:
> > On Wednesday, March 26, 2014 at 11:43:27 AM, Marek Vasut wrote:
> > > On Wednesday, March 26, 2014 at 04:08:27 AM, Yao Yuan wrote:
> > >
> > > [...]
> > >
> > > > > > + i2c_imx->use_dma = false;
> > > > > > + } else if (i2c_imx_dma_request(i2c_imx,
> > > > > > +(dma_addr_t)phy_addr))
> > >
> > > {
> > >
> > > > > > + dev_info(&pdev->dev,
> > > > > > + "can't request dma chan, faild use dma.
> \n");
> > > > > > + i2c_imx->use_dma = false;
> > > > > > + } else {
> > > > > > + i2c_imx->use_dma = true;
> > > > > > + }
> > > > >
> > > > > Can you not just check if i2c_imx->dma is valid pointer or NULL
> > >
> > > pointer ?
> > >
> > > > > Then you won't need a separate variable, for this purpose ...
> right ?
> > > >
> > > > Sorry and I think what I know is just to check whether it is NULL.
> > > > Then for the second question, maybe there are some other ways, But
> > > > I think it is more tidy and easier understanding for using a
> > > > separate variable, for this purpose.
> > >
> > > You are just wasting space and duplicating data, unless I am wrong.
> >
> > Well, Do you have a better idea? Although I think it's necessary.
>
> I think we disconnected here, sorry. Why can you not use (i2c_imx->dma !=
> NULL) instead of (i2c_imx->use_dma == true) please ?
>
But there are two judge conditions. But only the "i2c_imx->dma", but also whether "i2c_imx_dma_request" success.
"i2c_imx->use_dma == true" be equivalent to "i2c_imx->dma != NULL && !i2c_imx_dma_request()"
^ permalink raw reply [flat|nested] 33+ messages in thread
* Re: [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
@ 2014-03-26 7:26 ` Marek Vasut
0 siblings, 0 replies; 33+ messages in thread
From: Marek Vasut @ 2014-03-26 7:26 UTC (permalink / raw)
To: Yao Yuan
Cc: wsa, mark.rutland, shawn.guo, linux-kernel, linux-arm-kernel, linux-i2c
On Wednesday, March 26, 2014 at 08:08:28 AM, Yao Yuan wrote:
> On Wednesday, March 26, 2014 at 02:27:46 PM, Marek Vasut wrote:
> > On Wednesday, March 26, 2014 at 06:56:34 AM, Yao Yuan wrote:
> > > On Wednesday, March 26, 2014 at 11:43:27 AM, Marek Vasut wrote:
> > > > On Wednesday, March 26, 2014 at 04:08:27 AM, Yao Yuan wrote:
> > > >
> > > > [...]
> > > >
> > > > > > > + i2c_imx->use_dma = false;
> > > > > > > + } else if (i2c_imx_dma_request(i2c_imx,
> > > > > > > +(dma_addr_t)phy_addr))
> > > >
> > > > {
> > > >
> > > > > > > + dev_info(&pdev->dev,
> > > > > > > + "can't request dma chan, faild use dma.
> >
> > \n");
> >
> > > > > > > + i2c_imx->use_dma = false;
> > > > > > > + } else {
> > > > > > > + i2c_imx->use_dma = true;
> > > > > > > + }
> > > > > >
> > > > > > Can you not just check if i2c_imx->dma is valid pointer or NULL
> > > >
> > > > pointer ?
> > > >
> > > > > > Then you won't need a separate variable, for this purpose ...
> >
> > right ?
> >
> > > > > Sorry and I think what I know is just to check whether it is NULL.
> > > > > Then for the second question, maybe there are some other ways, But
> > > > > I think it is more tidy and easier understanding for using a
> > > > > separate variable, for this purpose.
> > > >
> > > > You are just wasting space and duplicating data, unless I am wrong.
> > >
> > > Well, Do you have a better idea? Although I think it's necessary.
> >
> > I think we disconnected here, sorry. Why can you not use (i2c_imx->dma !=
> > NULL) instead of (i2c_imx->use_dma == true) please ?
>
> But there are two judge conditions. But only the "i2c_imx->dma", but also
> whether "i2c_imx_dma_request" success.
>
> "i2c_imx->use_dma == true" be equivalent to "i2c_imx->dma != NULL &&
> !i2c_imx_dma_request()"
+ /* Init DMA config if support*/
+ i2c_imx->dma = devm_kzalloc(&pdev->dev, sizeof(struct imx_i2c_dma),
+ GFP_KERNEL);
+ if (!i2c_imx->dma) {
+ dev_info(&pdev->dev,
+ "can't allocate dma struct faild use dma.\n");
+ i2c_imx->use_dma = false;
+ } else if (i2c_imx_dma_request(i2c_imx, (dma_addr_t)phy_addr)) {
+ dev_info(&pdev->dev,
+ "can't request dma chan, faild use dma.\n");
+ i2c_imx->use_dma = false;
+ } else {
+ i2c_imx->use_dma = true;
+ }
OK, looking at this one more time, why don't you wrap the allocation of i2c_imx-
>dma into i2c_imx_dma_request() ? Even better, you can allocate *dma as a local
variable in i2c_imx_dma_request() and then assign it into i2c_imx->dma only at
the end of the i2c_imx_dma_request() function , at the point where you are sure
nothing failed. Then you can check i2c_imx->dma != NULL throughout the code to
check if the DMA is available, no ?
Shawn, Wolfram, am I talking nonsense or am I just not connecting ?
Best regards,
Marek Vasut
^ permalink raw reply [flat|nested] 33+ messages in thread
* Re: [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
@ 2014-03-26 7:26 ` Marek Vasut
0 siblings, 0 replies; 33+ messages in thread
From: Marek Vasut @ 2014-03-26 7:26 UTC (permalink / raw)
To: Yao Yuan
Cc: wsa-z923LK4zBo2bacvFa/9K2g, mark.rutland-5wv7dgnIgG8,
shawn.guo-QSEj5FYQhm4dnm+yROfE0A,
linux-kernel-u79uwXL29TY76Z2rM5mHXA,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
linux-i2c-u79uwXL29TY76Z2rM5mHXA
On Wednesday, March 26, 2014 at 08:08:28 AM, Yao Yuan wrote:
> On Wednesday, March 26, 2014 at 02:27:46 PM, Marek Vasut wrote:
> > On Wednesday, March 26, 2014 at 06:56:34 AM, Yao Yuan wrote:
> > > On Wednesday, March 26, 2014 at 11:43:27 AM, Marek Vasut wrote:
> > > > On Wednesday, March 26, 2014 at 04:08:27 AM, Yao Yuan wrote:
> > > >
> > > > [...]
> > > >
> > > > > > > + i2c_imx->use_dma = false;
> > > > > > > + } else if (i2c_imx_dma_request(i2c_imx,
> > > > > > > +(dma_addr_t)phy_addr))
> > > >
> > > > {
> > > >
> > > > > > > + dev_info(&pdev->dev,
> > > > > > > + "can't request dma chan, faild use dma.
> >
> > \n");
> >
> > > > > > > + i2c_imx->use_dma = false;
> > > > > > > + } else {
> > > > > > > + i2c_imx->use_dma = true;
> > > > > > > + }
> > > > > >
> > > > > > Can you not just check if i2c_imx->dma is valid pointer or NULL
> > > >
> > > > pointer ?
> > > >
> > > > > > Then you won't need a separate variable, for this purpose ...
> >
> > right ?
> >
> > > > > Sorry and I think what I know is just to check whether it is NULL.
> > > > > Then for the second question, maybe there are some other ways, But
> > > > > I think it is more tidy and easier understanding for using a
> > > > > separate variable, for this purpose.
> > > >
> > > > You are just wasting space and duplicating data, unless I am wrong.
> > >
> > > Well, Do you have a better idea? Although I think it's necessary.
> >
> > I think we disconnected here, sorry. Why can you not use (i2c_imx->dma !=
> > NULL) instead of (i2c_imx->use_dma == true) please ?
>
> But there are two judge conditions. But only the "i2c_imx->dma", but also
> whether "i2c_imx_dma_request" success.
>
> "i2c_imx->use_dma == true" be equivalent to "i2c_imx->dma != NULL &&
> !i2c_imx_dma_request()"
+ /* Init DMA config if support*/
+ i2c_imx->dma = devm_kzalloc(&pdev->dev, sizeof(struct imx_i2c_dma),
+ GFP_KERNEL);
+ if (!i2c_imx->dma) {
+ dev_info(&pdev->dev,
+ "can't allocate dma struct faild use dma.\n");
+ i2c_imx->use_dma = false;
+ } else if (i2c_imx_dma_request(i2c_imx, (dma_addr_t)phy_addr)) {
+ dev_info(&pdev->dev,
+ "can't request dma chan, faild use dma.\n");
+ i2c_imx->use_dma = false;
+ } else {
+ i2c_imx->use_dma = true;
+ }
OK, looking at this one more time, why don't you wrap the allocation of i2c_imx-
>dma into i2c_imx_dma_request() ? Even better, you can allocate *dma as a local
variable in i2c_imx_dma_request() and then assign it into i2c_imx->dma only at
the end of the i2c_imx_dma_request() function , at the point where you are sure
nothing failed. Then you can check i2c_imx->dma != NULL throughout the code to
check if the DMA is available, no ?
Shawn, Wolfram, am I talking nonsense or am I just not connecting ?
Best regards,
Marek Vasut
^ permalink raw reply [flat|nested] 33+ messages in thread
* [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
@ 2014-03-26 7:26 ` Marek Vasut
0 siblings, 0 replies; 33+ messages in thread
From: Marek Vasut @ 2014-03-26 7:26 UTC (permalink / raw)
To: linux-arm-kernel
On Wednesday, March 26, 2014 at 08:08:28 AM, Yao Yuan wrote:
> On Wednesday, March 26, 2014 at 02:27:46 PM, Marek Vasut wrote:
> > On Wednesday, March 26, 2014 at 06:56:34 AM, Yao Yuan wrote:
> > > On Wednesday, March 26, 2014 at 11:43:27 AM, Marek Vasut wrote:
> > > > On Wednesday, March 26, 2014 at 04:08:27 AM, Yao Yuan wrote:
> > > >
> > > > [...]
> > > >
> > > > > > > + i2c_imx->use_dma = false;
> > > > > > > + } else if (i2c_imx_dma_request(i2c_imx,
> > > > > > > +(dma_addr_t)phy_addr))
> > > >
> > > > {
> > > >
> > > > > > > + dev_info(&pdev->dev,
> > > > > > > + "can't request dma chan, faild use dma.
> >
> > \n");
> >
> > > > > > > + i2c_imx->use_dma = false;
> > > > > > > + } else {
> > > > > > > + i2c_imx->use_dma = true;
> > > > > > > + }
> > > > > >
> > > > > > Can you not just check if i2c_imx->dma is valid pointer or NULL
> > > >
> > > > pointer ?
> > > >
> > > > > > Then you won't need a separate variable, for this purpose ...
> >
> > right ?
> >
> > > > > Sorry and I think what I know is just to check whether it is NULL.
> > > > > Then for the second question, maybe there are some other ways, But
> > > > > I think it is more tidy and easier understanding for using a
> > > > > separate variable, for this purpose.
> > > >
> > > > You are just wasting space and duplicating data, unless I am wrong.
> > >
> > > Well, Do you have a better idea? Although I think it's necessary.
> >
> > I think we disconnected here, sorry. Why can you not use (i2c_imx->dma !=
> > NULL) instead of (i2c_imx->use_dma == true) please ?
>
> But there are two judge conditions. But only the "i2c_imx->dma", but also
> whether "i2c_imx_dma_request" success.
>
> "i2c_imx->use_dma == true" be equivalent to "i2c_imx->dma != NULL &&
> !i2c_imx_dma_request()"
+ /* Init DMA config if support*/
+ i2c_imx->dma = devm_kzalloc(&pdev->dev, sizeof(struct imx_i2c_dma),
+ GFP_KERNEL);
+ if (!i2c_imx->dma) {
+ dev_info(&pdev->dev,
+ "can't allocate dma struct faild use dma.\n");
+ i2c_imx->use_dma = false;
+ } else if (i2c_imx_dma_request(i2c_imx, (dma_addr_t)phy_addr)) {
+ dev_info(&pdev->dev,
+ "can't request dma chan, faild use dma.\n");
+ i2c_imx->use_dma = false;
+ } else {
+ i2c_imx->use_dma = true;
+ }
OK, looking at this one more time, why don't you wrap the allocation of i2c_imx-
>dma into i2c_imx_dma_request() ? Even better, you can allocate *dma as a local
variable in i2c_imx_dma_request() and then assign it into i2c_imx->dma only at
the end of the i2c_imx_dma_request() function , at the point where you are sure
nothing failed. Then you can check i2c_imx->dma != NULL throughout the code to
check if the DMA is available, no ?
Shawn, Wolfram, am I talking nonsense or am I just not connecting ?
Best regards,
Marek Vasut
^ permalink raw reply [flat|nested] 33+ messages in thread
* Re: [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
@ 2014-04-03 7:37 ` Shawn Guo
0 siblings, 0 replies; 33+ messages in thread
From: Shawn Guo @ 2014-04-03 7:37 UTC (permalink / raw)
To: Marek Vasut
Cc: Yao Yuan, wsa, mark.rutland, linux-kernel, linux-arm-kernel, linux-i2c
On Wed, Mar 26, 2014 at 08:26:27AM +0100, Marek Vasut wrote:
> > > I think we disconnected here, sorry. Why can you not use (i2c_imx->dma !=
> > > NULL) instead of (i2c_imx->use_dma == true) please ?
> >
> > But there are two judge conditions. But only the "i2c_imx->dma", but also
> > whether "i2c_imx_dma_request" success.
> >
> > "i2c_imx->use_dma == true" be equivalent to "i2c_imx->dma != NULL &&
> > !i2c_imx_dma_request()"
>
> + /* Init DMA config if support*/
> + i2c_imx->dma = devm_kzalloc(&pdev->dev, sizeof(struct imx_i2c_dma),
> + GFP_KERNEL);
> + if (!i2c_imx->dma) {
> + dev_info(&pdev->dev,
> + "can't allocate dma struct faild use dma.\n");
> + i2c_imx->use_dma = false;
> + } else if (i2c_imx_dma_request(i2c_imx, (dma_addr_t)phy_addr)) {
> + dev_info(&pdev->dev,
> + "can't request dma chan, faild use dma.\n");
> + i2c_imx->use_dma = false;
> + } else {
> + i2c_imx->use_dma = true;
> + }
>
> OK, looking at this one more time, why don't you wrap the allocation of i2c_imx-
> >dma into i2c_imx_dma_request() ? Even better, you can allocate *dma as a local
> variable in i2c_imx_dma_request() and then assign it into i2c_imx->dma only at
> the end of the i2c_imx_dma_request() function , at the point where you are sure
> nothing failed. Then you can check i2c_imx->dma != NULL throughout the code to
> check if the DMA is available, no ?
>
> Shawn, Wolfram, am I talking nonsense or am I just not connecting ?
I'm with you, Marek.
Shawn
^ permalink raw reply [flat|nested] 33+ messages in thread
* Re: [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
@ 2014-04-03 7:37 ` Shawn Guo
0 siblings, 0 replies; 33+ messages in thread
From: Shawn Guo @ 2014-04-03 7:37 UTC (permalink / raw)
To: Marek Vasut
Cc: Yao Yuan, wsa-z923LK4zBo2bacvFa/9K2g, mark.rutland-5wv7dgnIgG8,
linux-kernel-u79uwXL29TY76Z2rM5mHXA,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
linux-i2c-u79uwXL29TY76Z2rM5mHXA
On Wed, Mar 26, 2014 at 08:26:27AM +0100, Marek Vasut wrote:
> > > I think we disconnected here, sorry. Why can you not use (i2c_imx->dma !=
> > > NULL) instead of (i2c_imx->use_dma == true) please ?
> >
> > But there are two judge conditions. But only the "i2c_imx->dma", but also
> > whether "i2c_imx_dma_request" success.
> >
> > "i2c_imx->use_dma == true" be equivalent to "i2c_imx->dma != NULL &&
> > !i2c_imx_dma_request()"
>
> + /* Init DMA config if support*/
> + i2c_imx->dma = devm_kzalloc(&pdev->dev, sizeof(struct imx_i2c_dma),
> + GFP_KERNEL);
> + if (!i2c_imx->dma) {
> + dev_info(&pdev->dev,
> + "can't allocate dma struct faild use dma.\n");
> + i2c_imx->use_dma = false;
> + } else if (i2c_imx_dma_request(i2c_imx, (dma_addr_t)phy_addr)) {
> + dev_info(&pdev->dev,
> + "can't request dma chan, faild use dma.\n");
> + i2c_imx->use_dma = false;
> + } else {
> + i2c_imx->use_dma = true;
> + }
>
> OK, looking at this one more time, why don't you wrap the allocation of i2c_imx-
> >dma into i2c_imx_dma_request() ? Even better, you can allocate *dma as a local
> variable in i2c_imx_dma_request() and then assign it into i2c_imx->dma only at
> the end of the i2c_imx_dma_request() function , at the point where you are sure
> nothing failed. Then you can check i2c_imx->dma != NULL throughout the code to
> check if the DMA is available, no ?
>
> Shawn, Wolfram, am I talking nonsense or am I just not connecting ?
I'm with you, Marek.
Shawn
^ permalink raw reply [flat|nested] 33+ messages in thread
* [PATCH v3 1/2] i2c: add DMA support for freescale i2c driver
@ 2014-04-03 7:37 ` Shawn Guo
0 siblings, 0 replies; 33+ messages in thread
From: Shawn Guo @ 2014-04-03 7:37 UTC (permalink / raw)
To: linux-arm-kernel
On Wed, Mar 26, 2014 at 08:26:27AM +0100, Marek Vasut wrote:
> > > I think we disconnected here, sorry. Why can you not use (i2c_imx->dma !=
> > > NULL) instead of (i2c_imx->use_dma == true) please ?
> >
> > But there are two judge conditions. But only the "i2c_imx->dma", but also
> > whether "i2c_imx_dma_request" success.
> >
> > "i2c_imx->use_dma == true" be equivalent to "i2c_imx->dma != NULL &&
> > !i2c_imx_dma_request()"
>
> + /* Init DMA config if support*/
> + i2c_imx->dma = devm_kzalloc(&pdev->dev, sizeof(struct imx_i2c_dma),
> + GFP_KERNEL);
> + if (!i2c_imx->dma) {
> + dev_info(&pdev->dev,
> + "can't allocate dma struct faild use dma.\n");
> + i2c_imx->use_dma = false;
> + } else if (i2c_imx_dma_request(i2c_imx, (dma_addr_t)phy_addr)) {
> + dev_info(&pdev->dev,
> + "can't request dma chan, faild use dma.\n");
> + i2c_imx->use_dma = false;
> + } else {
> + i2c_imx->use_dma = true;
> + }
>
> OK, looking at this one more time, why don't you wrap the allocation of i2c_imx-
> >dma into i2c_imx_dma_request() ? Even better, you can allocate *dma as a local
> variable in i2c_imx_dma_request() and then assign it into i2c_imx->dma only at
> the end of the i2c_imx_dma_request() function , at the point where you are sure
> nothing failed. Then you can check i2c_imx->dma != NULL throughout the code to
> check if the DMA is available, no ?
>
> Shawn, Wolfram, am I talking nonsense or am I just not connecting ?
I'm with you, Marek.
Shawn
^ permalink raw reply [flat|nested] 33+ messages in thread
end of thread, other threads:[~2014-04-03 7:37 UTC | newest]
Thread overview: 33+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2014-03-13 1:47 [PATCH v3 0/2] i2c: add DMA support for freescale i2c driver Yuan Yao
2014-03-13 1:47 ` Yuan Yao
2014-03-13 1:47 ` Yuan Yao
2014-03-13 1:47 ` [PATCH v3 1/2] " Yuan Yao
2014-03-13 1:47 ` Yuan Yao
2014-03-13 1:47 ` Yuan Yao
2014-03-23 3:49 ` Marek Vasut
2014-03-23 3:49 ` Marek Vasut
2014-03-23 3:49 ` Marek Vasut
2014-03-26 3:08 ` Yao Yuan
2014-03-26 3:08 ` Yao Yuan
2014-03-26 3:08 ` Yao Yuan
2014-03-26 3:42 ` Marek Vasut
2014-03-26 3:42 ` Marek Vasut
2014-03-26 3:42 ` Marek Vasut
2014-03-26 5:56 ` Yao Yuan
2014-03-26 5:56 ` Yao Yuan
2014-03-26 5:56 ` Yao Yuan
2014-03-26 6:26 ` Marek Vasut
2014-03-26 6:26 ` Marek Vasut
2014-03-26 6:26 ` Marek Vasut
2014-03-26 7:08 ` Yao Yuan
2014-03-26 7:08 ` Yao Yuan
2014-03-26 7:08 ` Yao Yuan
2014-03-26 7:26 ` Marek Vasut
2014-03-26 7:26 ` Marek Vasut
2014-03-26 7:26 ` Marek Vasut
2014-04-03 7:37 ` Shawn Guo
2014-04-03 7:37 ` Shawn Guo
2014-04-03 7:37 ` Shawn Guo
2014-03-13 1:47 ` [PATCH v3 2/2] Documentation:add " Yuan Yao
2014-03-13 1:47 ` Yuan Yao
2014-03-13 1:47 ` Yuan Yao
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