[PATCH v3 3/3] i2c/at91: adopt pinctrl support

From: Wenyou Yang
Date: Fri Oct 24 2014 - 02:55:44 EST


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@xxxxxxxxx>
---
drivers/i2c/busses/i2c-at91.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/drivers/i2c/busses/i2c-at91.c b/drivers/i2c/busses/i2c-at91.c
index 6a84a2a..290caf1 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 */
@@ -747,6 +748,8 @@ 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;
@@ -851,6 +854,8 @@ static int at91_twi_runtime_suspend(struct device *dev)

clk_disable_unprepare(twi_dev->clk);

+ pinctrl_pm_select_sleep_state(dev);
+
return 0;
}

@@ -858,6 +863,8 @@ 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);
}

--
1.7.9.5

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