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pwm: sun4i: Add an optional probe for bus clock 

H6 PWM core needs bus clock to be enabled in order to work.

Add an optional probe for it.

Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Signed-off-by: Clément Péron <peron.clem@gmail.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
This commit is contained in:
Jernej Skrabec 2019-11-24 18:29:05 +01:00 committed by Thierry Reding
parent b8d74644f3
commit 5b090b430d
1 changed files with 23 additions and 0 deletions
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23
drivers/pwm/pwm-sun4i.c
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@ -78,6 +78,7 @@ struct sun4i_pwm_data {
struct sun4i_pwm_chip { struct sun4i_pwm_chip {
struct pwm_chip chip; struct pwm_chip chip;
struct clk *bus_clk;
struct clk *clk; struct clk *clk;
struct reset_control *rst; struct reset_control *rst;
void __iomem *base; void __iomem *base;
@ -391,6 +392,14 @@ static int sun4i_pwm_probe(struct platform_device *pdev)
} }
} }
pwm->bus_clk = devm_clk_get_optional(&pdev->dev, "bus");
if (IS_ERR(pwm->bus_clk)) {
if (PTR_ERR(pwm->rst) != -EPROBE_DEFER)
dev_err(&pdev->dev, "get bus clock failed %pe\n",
pwm->bus_clk);
return PTR_ERR(pwm->bus_clk);
}
pwm->rst = devm_reset_control_get_optional_shared(&pdev->dev, NULL); pwm->rst = devm_reset_control_get_optional_shared(&pdev->dev, NULL);
if (IS_ERR(pwm->rst)) { if (IS_ERR(pwm->rst)) {
if (PTR_ERR(pwm->rst) != -EPROBE_DEFER) if (PTR_ERR(pwm->rst) != -EPROBE_DEFER)
@ -407,6 +416,17 @@ static int sun4i_pwm_probe(struct platform_device *pdev)
return ret; return ret;
} }
/*
* We're keeping the bus clock on for the sake of simplicity.
* Actually it only needs to be on for hardware register accesses.
*/
ret = clk_prepare_enable(pwm->bus_clk);
if (ret) {
dev_err(&pdev->dev, "cannot prepare and enable bus_clk %pe\n",
ERR_PTR(ret));
goto err_bus;
}
pwm->chip.dev = &pdev->dev; pwm->chip.dev = &pdev->dev;
pwm->chip.ops = &sun4i_pwm_ops; pwm->chip.ops = &sun4i_pwm_ops;
pwm->chip.base = -1; pwm->chip.base = -1;
@ -427,6 +447,8 @@ static int sun4i_pwm_probe(struct platform_device *pdev)
return 0; return 0;
err_pwm_add: err_pwm_add:
clk_disable_unprepare(pwm->bus_clk);
err_bus:
reset_control_assert(pwm->rst); reset_control_assert(pwm->rst);
return ret; return ret;
@ -441,6 +463,7 @@ static int sun4i_pwm_remove(struct platform_device *pdev)
if (ret) if (ret)
return ret; return ret;
clk_disable_unprepare(pwm->bus_clk);
reset_control_assert(pwm->rst); reset_control_assert(pwm->rst);
return 0; return 0;