Commit 17f88151 authored by Franklin S Cooper Jr's avatar Franklin S Cooper Jr Committed by Wolfram Sang
Browse files

i2c: davinci: Add PM Runtime Support 



66AK2G has I2C instances that are not apart of the ALWAYS_ON power domain
unlike other Keystone 2 SoCs and OMAPL138. Therefore, pm_runtime
is required to insure the power domain used by the specific I2C instance is
properly turned on along with its functional clock.

Signed-off-by: default avatarFranklin S Cooper Jr <fcooper@ti.com>
Acked-by: default avatarSekhar Nori <nsekhar@ti.com>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
parent 98e82010

drivers/i2c/busses/i2c-davinci.c

+55 −12
Original line number Diff line number Diff line
@@ -36,6 +36,7 @@ 
#include <linux/gpio.h>

#include <linux/of_device.h>

#include <linux/platform_data/i2c-davinci.h>

#include <linux/pm_runtime.h>



/* ----- global defines ----------------------------------------------- */
@@ -122,6 +123,9 @@ 
/* set the SDA GPIO low */

#define DAVINCI_I2C_DCLR_PDCLR1	BIT(1)



/* timeout for pm runtime autosuspend */

#define DAVINCI_I2C_PM_TIMEOUT	1000	/* ms */



struct davinci_i2c_dev {

	struct device           *dev;

	void __iomem		*base;
@@ -541,10 +545,17 @@ i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) 


	dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num);



	ret = pm_runtime_get_sync(dev->dev);

	if (ret < 0) {

		dev_err(dev->dev, "Failed to runtime_get device: %d\n", ret);

		pm_runtime_put_noidle(dev->dev);

		return ret;

	}



	ret = i2c_davinci_wait_bus_not_busy(dev);

	if (ret < 0) {

		dev_warn(dev->dev, "timeout waiting for bus ready\n");

		return ret;

		goto out;

	}



	for (i = 0; i < num; i++) {
@@ -552,14 +563,19 @@ i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) 
		dev_dbg(dev->dev, "%s [%d/%d] ret: %d\n", __func__, i + 1, num,

			ret);

		if (ret < 0)

			return ret;

			goto out;

	}



	ret = num;

#ifdef CONFIG_CPU_FREQ

	complete(&dev->xfr_complete);

#endif



	return num;

out:

	pm_runtime_mark_last_busy(dev->dev);

	pm_runtime_put_autosuspend(dev->dev);



	return ret;

}



static u32 i2c_davinci_func(struct i2c_adapter *adap)
@@ -599,6 +615,9 @@ static irqreturn_t i2c_davinci_isr(int this_irq, void *dev_id) 
	int count = 0;

	u16 w;



	if (pm_runtime_suspended(dev->dev))

		return IRQ_NONE;



	while ((stat = davinci_i2c_read_reg(dev, DAVINCI_I2C_IVR_REG))) {

		dev_dbg(dev->dev, "%s: stat=0x%x\n", __func__, stat);

		if (count++ == 100) {
@@ -802,13 +821,24 @@ static int davinci_i2c_probe(struct platform_device *pdev) 
	dev->clk = devm_clk_get(&pdev->dev, NULL);

	if (IS_ERR(dev->clk))

		return PTR_ERR(dev->clk);

	clk_prepare_enable(dev->clk);



	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	dev->base = devm_ioremap_resource(&pdev->dev, mem);

	if (IS_ERR(dev->base)) {

		r = PTR_ERR(dev->base);

		goto err_unuse_clocks;

		return PTR_ERR(dev->base);

	}



	pm_runtime_set_autosuspend_delay(dev->dev,

					 DAVINCI_I2C_PM_TIMEOUT);

	pm_runtime_use_autosuspend(dev->dev);



	pm_runtime_enable(dev->dev);



	r = pm_runtime_get_sync(dev->dev);

	if (r < 0) {

		dev_err(dev->dev, "failed to runtime_get device: %d\n", r);

		pm_runtime_put_noidle(dev->dev);

		return r;

	}



	i2c_davinci_init(dev);
@@ -849,27 +879,40 @@ static int davinci_i2c_probe(struct platform_device *pdev) 
	if (r)

		goto err_unuse_clocks;



	pm_runtime_mark_last_busy(dev->dev);

	pm_runtime_put_autosuspend(dev->dev);



	return 0;



err_unuse_clocks:

	clk_disable_unprepare(dev->clk);

	dev->clk = NULL;

	pm_runtime_dont_use_autosuspend(dev->dev);

	pm_runtime_put_sync(dev->dev);

	pm_runtime_disable(dev->dev);



	return r;

}



static int davinci_i2c_remove(struct platform_device *pdev)

{

	struct davinci_i2c_dev *dev = platform_get_drvdata(pdev);

	int ret;



	i2c_davinci_cpufreq_deregister(dev);



	i2c_del_adapter(&dev->adapter);



	clk_disable_unprepare(dev->clk);

	dev->clk = NULL;

	ret = pm_runtime_get_sync(&pdev->dev);

	if (ret < 0) {

		pm_runtime_put_noidle(&pdev->dev);

		return ret;

	}



	davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, 0);



	pm_runtime_dont_use_autosuspend(dev->dev);

	pm_runtime_put_sync(dev->dev);

	pm_runtime_disable(dev->dev);



	return 0;

}
@@ -880,7 +923,6 @@ static int davinci_i2c_suspend(struct device *dev) 


	/* put I2C into reset */

	davinci_i2c_reset_ctrl(i2c_dev, 0);

	clk_disable_unprepare(i2c_dev->clk);



	return 0;

}
@@ -889,7 +931,6 @@ static int davinci_i2c_resume(struct device *dev) 
{

	struct davinci_i2c_dev *i2c_dev = dev_get_drvdata(dev);



	clk_prepare_enable(i2c_dev->clk);

	/* take I2C out of reset */

	davinci_i2c_reset_ctrl(i2c_dev, 1);
@@ -899,6 +940,8 @@ static int davinci_i2c_resume(struct device *dev) 
static const struct dev_pm_ops davinci_i2c_pm = {

	.suspend        = davinci_i2c_suspend,

	.resume         = davinci_i2c_resume,

	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,

				      pm_runtime_force_resume)

};



#define davinci_i2c_pm_ops (&davinci_i2c_pm)

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