Hello Sekhar,
On 13.07.2012 15:57, Sekhar Nori wrote:
Hi Heiko,
On 5/30/2012 3:49 PM, Heiko Schocher wrote:
add of support for the davinci i2c driver.
Signed-off-by: Heiko Schocher<hs@xxxxxxx>
Cc: davinci-linux-open-source@xxxxxxxxxxxxxxxxxxxx
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: devicetree-discuss@xxxxxxxxxxxxxxxx
Cc: linux-i2c@xxxxxxxxxxxxxxx
Cc: Ben Dooks<ben-linux@xxxxxxxxx>
Cc: Wolfram Sang<w.sang@xxxxxxxxxxxxxx>
Cc: Grant Likely<grant.likely@xxxxxxxxxxxx>
Cc: Sekhar Nori<nsekhar@xxxxxx>
Cc: Wolfgang Denk<wd@xxxxxxx>
Cc: Sylwester Nawrocki<s.nawrocki@xxxxxxxxxxx>
[...]
diff --git a/Documentation/devicetree/bindings/arm/davinci/i2c.txt b/Documentation/devicetree/bindings/arm/davinci/i2c.txt
new file mode 100644
index 0000000..e98a025
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/davinci/i2c.txt
[...]
diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c
index a76d85f..4e7a966 100644
--- a/drivers/i2c/busses/i2c-davinci.c
+++ b/drivers/i2c/busses/i2c-davinci.c
@@ -38,9 +38,12 @@
#include<linux/slab.h>
#include<linux/cpufreq.h>
#include<linux/gpio.h>
+#include<linux/of_i2c.h>
+#include<linux/of_device.h>
#include<mach/hardware.h>
#include<mach/i2c.h>
+#include<mach/mux.h>
Seems like a stray change. I was able to build and use just fine
without this include.
Hups. Good catch! Removed.
/* ----- global defines ----------------------------------------------- */
@@ -114,6 +117,7 @@ struct davinci_i2c_dev {
struct completion xfr_complete;
struct notifier_block freq_transition;
#endif
+ struct davinci_i2c_platform_data *pdata;
};
/* default platform data to use if not supplied in the platform_device */
@@ -149,13 +153,22 @@ static void generic_i2c_clock_pulse(unsigned int scl_pin)
}
}
+static struct davinci_i2c_platform_data
+ *i2c_get_plattformdata(struct davinci_i2c_dev *dev)
+{
+ if (dev->dev->platform_data == NULL)
+ return dev->pdata;
+
+ return dev->dev->platform_data;
+}
It seems to me that if we setup the newly introduced dev->pdata
member correctly once in probe, there should not be a need for this
function. We can also eliminate multiple checks for pdata in code.
See below for more.
Ok.
+
/* This routine does i2c bus recovery as specified in the
* i2c protocol Rev. 03 section 3.16 titled "Bus clear"
*/
static void i2c_recover_bus(struct davinci_i2c_dev *dev)
{
u32 flag = 0;
- struct davinci_i2c_platform_data *pdata = dev->dev->platform_data;
+ struct davinci_i2c_platform_data *pdata = i2c_get_plattformdata(dev);
dev_err(dev->dev, "initiating i2c bus recovery\n");
/* Send NACK to the slave */
@@ -187,7 +200,7 @@ static inline void davinci_i2c_reset_ctrl(struct davinci_i2c_dev *i2c_dev,
static void i2c_davinci_calc_clk_dividers(struct davinci_i2c_dev *dev)
{
- struct davinci_i2c_platform_data *pdata = dev->dev->platform_data;
+ struct davinci_i2c_platform_data *pdata = i2c_get_plattformdata(dev);
u16 psc;
u32 clk;
u32 d;
@@ -235,7 +248,7 @@ static void i2c_davinci_calc_clk_dividers(struct davinci_i2c_dev *dev)
*/
static int i2c_davinci_init(struct davinci_i2c_dev *dev)
{
- struct davinci_i2c_platform_data *pdata = dev->dev->platform_data;
+ struct davinci_i2c_platform_data *pdata = i2c_get_plattformdata(dev);
if (!pdata)
pdata =&davinci_i2c_platform_data_default;
@@ -308,7 +321,7 @@ static int
i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop)
{
struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
- struct davinci_i2c_platform_data *pdata = dev->dev->platform_data;
+ struct davinci_i2c_platform_data *pdata = i2c_get_plattformdata(dev);
u32 flag;
u16 w;
int r;
@@ -635,6 +648,12 @@ static struct i2c_algorithm i2c_davinci_algo = {
.functionality = i2c_davinci_func,
};
+static const struct of_device_id davinci_i2c_of_match[] = {
+ {.compatible = "ti,davinci-i2c", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, davinci_i2c_of_match);
+
static int davinci_i2c_probe(struct platform_device *pdev)
{
struct davinci_i2c_dev *dev;
@@ -676,6 +695,25 @@ static int davinci_i2c_probe(struct platform_device *pdev)
dev->irq = irq->start;
platform_set_drvdata(pdev, dev);
+ if ((dev->dev->platform_data == NULL)&&
+ (pdev->dev.of_node)) {
+ u32 prop;
+
+ dev->pdata = devm_kzalloc(&pdev->dev,
+ sizeof(struct davinci_i2c_platform_data), GFP_KERNEL);
+ if (!dev->pdata) {
+ r = -ENOMEM;
+ goto err_free_mem;
+ }
+ memcpy(dev->pdata,&davinci_i2c_platform_data_default,
+ sizeof(struct davinci_i2c_platform_data));
+ if (!of_property_read_u32(pdev->dev.of_node, "clock-frequency",
+ &prop))
+ dev->pdata->bus_freq = prop / 1000;
+ if (!of_property_read_u32(pdev->dev.of_node, "bus-delay",
+ &prop))
+ dev->pdata->bus_delay = prop;
You are leaving out two other platform data members (the gpio pins
corresponding to data and clock) from DT data. We should be able to
get that information from DT too, right?
Yes, but I had not ported the GPIO driver to OF ...
So, I took this patch and tried to see if pdata maintenance can be
simplified and came with the diff below. Can you have a look and see
if this makes sense? I tested this using i2cdetect both with and
without DT.
Tested your patch on the enbw_cmc board with a LM75 on the enbw_cmc
board, works fine. Can I post a "v6" of my patch, merged with your
patch below and your Signed-off?
---8<---
diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c
index 16d7645..d07c207 100644
--- a/drivers/i2c/busses/i2c-davinci.c
+++ b/drivers/i2c/busses/i2c-davinci.c
@@ -153,22 +153,13 @@ static void generic_i2c_clock_pulse(unsigned int scl_pin)
}
}
-static struct davinci_i2c_platform_data
- *i2c_get_plattformdata(struct davinci_i2c_dev *dev)
-{
- if (dev->dev->platform_data == NULL)
- return dev->pdata;
-
- return dev->dev->platform_data;
-}
-
/* This routine does i2c bus recovery as specified in the
* i2c protocol Rev. 03 section 3.16 titled "Bus clear"
*/
static void i2c_recover_bus(struct davinci_i2c_dev *dev)
{
u32 flag = 0;
- struct davinci_i2c_platform_data *pdata = i2c_get_plattformdata(dev);
+ struct davinci_i2c_platform_data *pdata = dev->pdata;
dev_err(dev->dev, "initiating i2c bus recovery\n");
/* Send NACK to the slave */
@@ -176,8 +167,7 @@ static void i2c_recover_bus(struct davinci_i2c_dev *dev)
flag |= DAVINCI_I2C_MDR_NACK;
/* write the data into mode register */
davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag);
- if (pdata)
- generic_i2c_clock_pulse(pdata->scl_pin);
+ generic_i2c_clock_pulse(pdata->scl_pin);
/* Send STOP */
flag = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
flag |= DAVINCI_I2C_MDR_STP;
@@ -200,7 +190,7 @@ static inline void davinci_i2c_reset_ctrl(struct davinci_i2c_dev *i2c_dev,
static void i2c_davinci_calc_clk_dividers(struct davinci_i2c_dev *dev)
{
- struct davinci_i2c_platform_data *pdata = i2c_get_plattformdata(dev);
+ struct davinci_i2c_platform_data *pdata = dev->pdata;
u16 psc;
u32 clk;
u32 d;
@@ -248,10 +238,7 @@ static void i2c_davinci_calc_clk_dividers(struct davinci_i2c_dev *dev)
*/
static int i2c_davinci_init(struct davinci_i2c_dev *dev)
{
- struct davinci_i2c_platform_data *pdata = i2c_get_plattformdata(dev);
-
- if (!pdata)
- pdata =&davinci_i2c_platform_data_default;
+ struct davinci_i2c_platform_data *pdata = dev->pdata;
/* put I2C into reset */
davinci_i2c_reset_ctrl(dev, 0);
@@ -321,13 +308,11 @@ static int
i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop)
{
struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
- struct davinci_i2c_platform_data *pdata = i2c_get_plattformdata(dev);
+ struct davinci_i2c_platform_data *pdata = dev->pdata;
u32 flag;
u16 w;
int r;
- if (!pdata)
- pdata =&davinci_i2c_platform_data_default;
/* Introduce a delay, required for some boards (e.g Davinci EVM) */
if (pdata->bus_delay)
udelay(pdata->bus_delay);
@@ -693,10 +678,10 @@ static int davinci_i2c_probe(struct platform_device *pdev)
#endif
dev->dev = get_device(&pdev->dev);
dev->irq = irq->start;
+ dev->pdata = dev->dev->platform_data;
platform_set_drvdata(pdev, dev);
- if ((dev->dev->platform_data == NULL)&&
- (pdev->dev.of_node)) {
+ if (!dev->pdata&& pdev->dev.of_node) {
u32 prop;
dev->pdata = devm_kzalloc(&pdev->dev,
@@ -713,7 +698,10 @@ static int davinci_i2c_probe(struct platform_device *pdev)
if (!of_property_read_u32(pdev->dev.of_node, "bus-delay",
&prop))
dev->pdata->bus_delay = prop;
+ } else if (!dev->pdata) {
+ dev->pdata =&davinci_i2c_platform_data_default;
}
+
dev->clk = clk_get(&pdev->dev, NULL);
if (IS_ERR(dev->clk)) {
r = -ENODEV;
bye,
Heiko
--
DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
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