Messages in this thread Patch in this message | | | From | Clément Péron <> | Subject | [PATCH v8 3/6] pwm: sun4i: Add an optional probe for bus clock | Date | Thu, 21 Nov 2019 20:58:59 +0100 |
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From: Jernej Skrabec <jernej.skrabec@siol.net>
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> --- drivers/pwm/pwm-sun4i.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+)
diff --git a/drivers/pwm/pwm-sun4i.c b/drivers/pwm/pwm-sun4i.c index 369990ae7d09..66befd8d6f9c 100644 --- a/drivers/pwm/pwm-sun4i.c +++ b/drivers/pwm/pwm-sun4i.c @@ -78,6 +78,7 @@ struct sun4i_pwm_data { struct sun4i_pwm_chip { struct pwm_chip chip; + struct clk *bus_clk; struct clk *clk; struct reset_control *rst; 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); if (IS_ERR(pwm->rst)) { if (PTR_ERR(pwm->rst) != -EPROBE_DEFER) @@ -407,6 +416,17 @@ static int sun4i_pwm_probe(struct platform_device *pdev) 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 %d\n", + ret); + goto err_bus; + } + pwm->chip.dev = &pdev->dev; pwm->chip.ops = &sun4i_pwm_ops; pwm->chip.base = -1; @@ -427,6 +447,8 @@ static int sun4i_pwm_probe(struct platform_device *pdev) return 0; err_pwm_add: + clk_disable_unprepare(pwm->bus_clk); +err_bus: reset_control_assert(pwm->rst); return ret; @@ -441,6 +463,7 @@ static int sun4i_pwm_remove(struct platform_device *pdev) if (ret) return ret; + clk_disable_unprepare(pwm->bus_clk); reset_control_assert(pwm->rst); return 0; -- 2.20.1
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