Commit 5dfbd2bd authored by Rohith Seelaboyina's avatar Rohith Seelaboyina Committed by Thierry Reding
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pwm: tegra: Add support for reset control 



Add reset control of the PWM controller to reset it before
accessing the PWM register.

Signed-off-by: default avatarRohith Seelaboyina <rseelaboyina@nvidia.com>
Signed-off-by: default avatarLaxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: default avatarThierry Reding <thierry.reding@gmail.com>
parent 4f57f5a0

drivers/pwm/pwm-tegra.c

+20 −0
Original line number Diff line number Diff line
@@ -29,6 +29,7 @@ 
#include <linux/pwm.h>

#include <linux/platform_device.h>

#include <linux/slab.h>

#include <linux/reset.h>



#define PWM_ENABLE	(1 << 31)

#define PWM_DUTY_WIDTH	8
@@ -41,6 +42,7 @@ struct tegra_pwm_chip { 
	struct device *dev;



	struct clk *clk;

	struct reset_control*rst;



	void __iomem *regs;

};
@@ -187,6 +189,15 @@ static int tegra_pwm_probe(struct platform_device *pdev) 
	if (IS_ERR(pwm->clk))

		return PTR_ERR(pwm->clk);



	pwm->rst = devm_reset_control_get(&pdev->dev, "pwm");

	if (IS_ERR(pwm->rst)) {

		ret = PTR_ERR(pwm->rst);

		dev_err(&pdev->dev, "Reset control is not found: %d\n", ret);

		return ret;

	}



	reset_control_deassert(pwm->rst);



	pwm->chip.dev = &pdev->dev;

	pwm->chip.ops = &tegra_pwm_ops;

	pwm->chip.base = -1;
@@ -195,6 +206,7 @@ static int tegra_pwm_probe(struct platform_device *pdev) 
	ret = pwmchip_add(&pwm->chip);

	if (ret < 0) {

		dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);

		reset_control_assert(pwm->rst);

		return ret;

	}
@@ -205,10 +217,15 @@ static int tegra_pwm_remove(struct platform_device *pdev) 
{

	struct tegra_pwm_chip *pc = platform_get_drvdata(pdev);

	unsigned int i;

	int err;



	if (WARN_ON(!pc))

		return -ENODEV;



	err = clk_prepare_enable(pc->clk);

	if (err < 0)

		return err;



	for (i = 0; i < pc->chip.npwm; i++) {

		struct pwm_device *pwm = &pc->chip.pwms[i];
@@ -221,6 +238,9 @@ static int tegra_pwm_remove(struct platform_device *pdev) 
		clk_disable_unprepare(pc->clk);

	}



	reset_control_assert(pc->rst);

	clk_disable_unprepare(pc->clk);



	return pwmchip_remove(&pc->chip);

}