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pwm: sun4i: Add an optional probe for reset line

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H6 PWM core needs deasserted reset line in order to work.

Add an optional probe for it.

Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Clément Péron <peron.clem@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
This commit is contained in:
Jernej Skrabec 2019-11-24 18:29:03 +01:00 committed by Thierry Reding
parent bd88d319ab
commit a7fe985633
1 changed files with 32 additions and 2 deletions
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34
drivers/pwm/pwm-sun4i.c
View file

@ -16,6 +16,7 @@
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/pwm.h>
#include <linux/reset.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/time.h>
@ -78,6 +79,7 @@ struct sun4i_pwm_data {
struct sun4i_pwm_chip {
struct pwm_chip chip;
struct clk *clk;
struct reset_control *rst;
void __iomem *base;
spinlock_t ctrl_lock;
const struct sun4i_pwm_data *data;
@ -364,6 +366,22 @@ static int sun4i_pwm_probe(struct platform_device *pdev)
if (IS_ERR(pwm->clk))
return PTR_ERR(pwm->clk);
pwm->rst = devm_reset_control_get_optional_shared(&pdev->dev, NULL);
if (IS_ERR(pwm->rst)) {
if (PTR_ERR(pwm->rst) != -EPROBE_DEFER)
dev_err(&pdev->dev, "get reset failed %pe\n",
pwm->rst);
return PTR_ERR(pwm->rst);
}
/* Deassert reset */
ret = reset_control_deassert(pwm->rst);
if (ret) {
dev_err(&pdev->dev, "cannot deassert reset control: %pe\n",
ERR_PTR(ret));
return ret;
}
pwm->chip.dev = &pdev->dev;
pwm->chip.ops = &sun4i_pwm_ops;
pwm->chip.base = -1;
@ -376,19 +394,31 @@ static int sun4i_pwm_probe(struct platform_device *pdev)
ret = pwmchip_add(&pwm->chip);
if (ret < 0) {
dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret);
return ret;
goto err_pwm_add;
}
platform_set_drvdata(pdev, pwm);
return 0;
err_pwm_add:
reset_control_assert(pwm->rst);
return ret;
}
static int sun4i_pwm_remove(struct platform_device *pdev)
{
struct sun4i_pwm_chip *pwm = platform_get_drvdata(pdev);
int ret;
return pwmchip_remove(&pwm->chip);
ret = pwmchip_remove(&pwm->chip);
if (ret)
return ret;
reset_control_assert(pwm->rst);
return 0;
}
static struct platform_driver sun4i_pwm_driver = {