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Commit 13d6eb20 authored by Fugang Duan's avatar Fugang Duan Committed by Wolfram Sang
Browse files

i2c: imx-lpi2c: add runtime pm support 



Add runtime pm support to dynamically manage the clock to avoid enable/disable
clock in frequently that can improve the i2c bus transfer performance.

And use pm_runtime_force_suspend/resume() instead of lpi2c_imx_suspend/resume().

Signed-off-by: default avatarFugang Duan <fugang.duan@nxp.com>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
parent fe34fbf9

drivers/i2c/busses/i2c-imx-lpi2c.c

+51 −17
Original line number Diff line number Diff line
@@ -30,6 +30,7 @@ 
#include <linux/of_device.h>

#include <linux/pinctrl/consumer.h>

#include <linux/platform_device.h>

#include <linux/pm_runtime.h>

#include <linux/sched.h>

#include <linux/slab.h>
@@ -90,6 +91,8 @@ 
#define FAST_PLUS_MAX_BITRATE	3400000

#define HIGHSPEED_MAX_BITRATE	5000000



#define I2C_PM_TIMEOUT		10 /* ms */



enum lpi2c_imx_mode {

	STANDARD,	/* 100+Kbps */

	FAST,		/* 400+Kbps */
@@ -274,8 +277,8 @@ static int lpi2c_imx_master_enable(struct lpi2c_imx_struct *lpi2c_imx) 
	unsigned int temp;

	int ret;



	ret = clk_enable(lpi2c_imx->clk);

	if (ret)

	ret = pm_runtime_get_sync(lpi2c_imx->adapter.dev.parent);

	if (ret < 0)

		return ret;



	temp = MCR_RST;
@@ -284,7 +287,7 @@ static int lpi2c_imx_master_enable(struct lpi2c_imx_struct *lpi2c_imx) 


	ret = lpi2c_imx_config(lpi2c_imx);

	if (ret)

		goto clk_disable;

		goto rpm_put;



	temp = readl(lpi2c_imx->base + LPI2C_MCR);

	temp |= MCR_MEN;
@@ -292,8 +295,9 @@ static int lpi2c_imx_master_enable(struct lpi2c_imx_struct *lpi2c_imx) 


	return 0;



clk_disable:

	clk_disable(lpi2c_imx->clk);

rpm_put:

	pm_runtime_mark_last_busy(lpi2c_imx->adapter.dev.parent);

	pm_runtime_put_autosuspend(lpi2c_imx->adapter.dev.parent);



	return ret;

}
@@ -306,7 +310,8 @@ static int lpi2c_imx_master_disable(struct lpi2c_imx_struct *lpi2c_imx) 
	temp &= ~MCR_MEN;

	writel(temp, lpi2c_imx->base + LPI2C_MCR);



	clk_disable(lpi2c_imx->clk);

	pm_runtime_mark_last_busy(lpi2c_imx->adapter.dev.parent);

	pm_runtime_put_autosuspend(lpi2c_imx->adapter.dev.parent);



	return 0;

}
@@ -606,22 +611,31 @@ static int lpi2c_imx_probe(struct platform_device *pdev) 
		return ret;

	}



	pm_runtime_set_autosuspend_delay(&pdev->dev, I2C_PM_TIMEOUT);

	pm_runtime_use_autosuspend(&pdev->dev);

	pm_runtime_get_noresume(&pdev->dev);

	pm_runtime_set_active(&pdev->dev);

	pm_runtime_enable(&pdev->dev);



	temp = readl(lpi2c_imx->base + LPI2C_PARAM);

	lpi2c_imx->txfifosize = 1 << (temp & 0x0f);

	lpi2c_imx->rxfifosize = 1 << ((temp >> 8) & 0x0f);



	clk_disable(lpi2c_imx->clk);



	ret = i2c_add_adapter(&lpi2c_imx->adapter);

	if (ret)

		goto clk_unprepare;

		goto rpm_disable;



	pm_runtime_mark_last_busy(&pdev->dev);

	pm_runtime_put_autosuspend(&pdev->dev);



	dev_info(&lpi2c_imx->adapter.dev, "LPI2C adapter registered\n");



	return 0;



clk_unprepare:

	clk_unprepare(lpi2c_imx->clk);

rpm_disable:

	pm_runtime_put(&pdev->dev);

	pm_runtime_disable(&pdev->dev);

	pm_runtime_dont_use_autosuspend(&pdev->dev);



	return ret;

}
@@ -632,28 +646,48 @@ static int lpi2c_imx_remove(struct platform_device *pdev) 


	i2c_del_adapter(&lpi2c_imx->adapter);



	clk_unprepare(lpi2c_imx->clk);

	pm_runtime_disable(&pdev->dev);

	pm_runtime_dont_use_autosuspend(&pdev->dev);



	return 0;

}



#ifdef CONFIG_PM_SLEEP

static int lpi2c_imx_suspend(struct device *dev)

static int lpi2c_runtime_suspend(struct device *dev)

{

	struct lpi2c_imx_struct *lpi2c_imx = dev_get_drvdata(dev);



	clk_disable_unprepare(lpi2c_imx->clk);

	pinctrl_pm_select_sleep_state(dev);



	return 0;

}



static int lpi2c_imx_resume(struct device *dev)

static int lpi2c_runtime_resume(struct device *dev)

{

	struct lpi2c_imx_struct *lpi2c_imx = dev_get_drvdata(dev);

	int ret;



	pinctrl_pm_select_default_state(dev);

	ret = clk_prepare_enable(lpi2c_imx->clk);

	if (ret) {

		dev_err(dev, "failed to enable I2C clock, ret=%d\n", ret);

		return ret;

	}



	return 0;

}

#endif



static SIMPLE_DEV_PM_OPS(imx_lpi2c_pm, lpi2c_imx_suspend, lpi2c_imx_resume);

static const struct dev_pm_ops lpi2c_pm_ops = {

	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,

				      pm_runtime_force_resume)

	SET_RUNTIME_PM_OPS(lpi2c_runtime_suspend,

			   lpi2c_runtime_resume, NULL)

};

#define IMX_LPI2C_PM      (&lpi2c_pm_ops)

#else

#define IMX_LPI2C_PM      NULL

#endif



static struct platform_driver lpi2c_imx_driver = {

	.probe = lpi2c_imx_probe,
@@ -661,7 +695,7 @@ static struct platform_driver lpi2c_imx_driver = { 
	.driver = {

		.name = DRIVER_NAME,

		.of_match_table = lpi2c_imx_of_match,

		.pm = &imx_lpi2c_pm,

		.pm = IMX_LPI2C_PM,

	},

};