[PATCH 3/6] i2c-davinci: introduce a dev-> function pointer for scl pulsing

From: Ben Gardiner
Date: Tue Apr 05 2011 - 17:39:13 EST


The current implementation of the I2C recovery routine checks whether
platform data ->scl_pin has been assigned and if so, the generic_i2c_clock_pulse
routine is executed.

In preparation for an alternative recovery routine; introduce a pulse_scl
function pointer to the driver private structure and assign it the value of
generic_i2c_clock_pulse on init if the scl_pin is assigned in platform data.

Signed-off-by: Ben Gardiner<bengardiner@xxxxxxxxxxxxxx>
Cc: Sekhar Nori <nsekhar@xxxxxx>
Cc: Ben Dooks <ben-linux@xxxxxxxxx>

---
drivers/i2c/busses/i2c-davinci.c | 20 +++++++++++++-------
1 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c
index 7011222..0a2c697 100644
--- a/drivers/i2c/busses/i2c-davinci.c
+++ b/drivers/i2c/busses/i2c-davinci.c
@@ -110,6 +110,7 @@ struct davinci_i2c_dev {
int stop;
u8 terminate;
struct i2c_adapter adapter;
+ void (*pulse_scl) (struct davinci_i2c_dev *dev);
#ifdef CONFIG_CPU_FREQ
struct completion xfr_complete;
struct notifier_block freq_transition;
@@ -165,16 +166,17 @@ static void i2c_davinci_dump_regs(struct davinci_i2c_dev *dev)
}

/* Generate a pulse on the i2c clock pin. */
-static void generic_i2c_clock_pulse(unsigned int scl_pin)
+static void generic_i2c_clock_pulse(struct davinci_i2c_dev *dev)
{
+ struct davinci_i2c_platform_data *pdata = dev->dev->platform_data;
u16 i;

- if (scl_pin) {
+ if (pdata->scl_pin) {
/* Send high and low on the SCL line */
for (i = 0; i < 9; i++) {
- gpio_set_value(scl_pin, 0);
+ gpio_set_value(pdata->scl_pin, 0);
udelay(20);
- gpio_set_value(scl_pin, 1);
+ gpio_set_value(pdata->scl_pin, 1);
udelay(20);
}
}
@@ -186,7 +188,6 @@ static void generic_i2c_clock_pulse(unsigned int scl_pin)
static void i2c_recover_bus(struct davinci_i2c_dev *dev)
{
u32 flag = 0;
- struct davinci_i2c_platform_data *pdata = dev->dev->platform_data;

i2c_davinci_dump_regs(dev);
dev_err(dev->dev, "initiating i2c bus recovery\n");
@@ -195,8 +196,8 @@ 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);
+ if (dev->pulse_scl)
+ dev->pulse_scl(dev);
/* Send STOP */
flag = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
flag |= DAVINCI_I2C_MDR_STP;
@@ -669,6 +670,7 @@ static struct i2c_algorithm i2c_davinci_algo = {

static int davinci_i2c_probe(struct platform_device *pdev)
{
+ struct davinci_i2c_platform_data *pdata;
struct davinci_i2c_dev *dev;
struct i2c_adapter *adap;
struct resource *mem, *irq, *ioarea;
@@ -751,6 +753,10 @@ static int davinci_i2c_probe(struct platform_device *pdev)
goto err_free_irq;
}

+ pdata = dev->dev->platform_data;
+ if (pdata->scl_pin)
+ dev->pulse_scl = generic_i2c_clock_pulse;
+
return 0;

err_free_irq:
--
1.7.1

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