[PATCH 3/3] i2c/at91: adopt pinctrl support

Wenyou Yang
2014-10-20T03:42:14Z

Amend the i2c at91 pin controller to optionally take a pin control
handle and set the state of the pins to:

- "default" on boot, resume and before performing an transfer
- "sleep" on suspend()

This should make it possible to optimize energy usage for the pins
both for the suspend/resume cycle

Signed-off-by: Wenyou Yang <wenyou.yang-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>
---
drivers/i2c/busses/i2c-at91.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-at91.c b/drivers/i2c/busses/i2c-at91.c
index 8f408f8..ed2c382 100644
--- a/drivers/i2c/busses/i2c-at91.c
+++ b/drivers/i2c/busses/i2c-at91.c
@@ -32,6 +32,7 @@
#include <linux/slab.h>
#include <linux/platform_data/dma-atmel.h>
#include <linux/pm_runtime.h>
+#include <linux/pinctrl/consumer.h>

#define DEFAULT_TWI_CLK_HZ 100000 /* max 400 Kbits/s */
#define AT91_I2C_TIMEOUT msecs_to_jiffies(100) /* transfer timeout */
@@ -748,6 +749,8 @@ static int at91_twi_probe(struct platform_device *pdev)
u32 phy_addr;
u32 bus_clk_rate;

+ pinctrl_pm_select_default_state(&pdev->dev);
+
dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
if (!dev)
return -ENOMEM;
@@ -850,8 +853,10 @@ static int at91_twi_suspend(struct device *dev)
{
struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);

- if (!pm_runtime_suspended(dev))
+ if (!pm_runtime_suspended(dev)) {
clk_disable_unprepare(twi_dev->clk);
+ pinctrl_pm_select_sleep_state(dev);
+ }

return 0;
}
@@ -862,6 +867,7 @@ static int at91_twi_resume(struct device *dev)
int ret;

if (!pm_runtime_suspended(dev)) {
+ pinctrl_pm_select_default_state(dev);
ret = clk_prepare_enable(twi_dev->clk);
if (ret)
return ret;
@@ -881,6 +887,8 @@ static int at91_twi_runtime_suspend(struct device *dev)

clk_disable_unprepare(twi_dev->clk);

+ pinctrl_pm_select_sleep_state(dev);
+
return 0;
}

@@ -888,6 +896,8 @@ static int at91_twi_runtime_resume(struct device *dev)
{
struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);

+ pinctrl_pm_select_default_state(dev);
+
return clk_prepare_enable(twi_dev->clk);
}
#endif
--
1.7.9.5