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authorJernej Skrabec <jernej.skrabec@siol.net>2019-11-24 18:29:05 +0100
committerThierry Reding <thierry.reding@gmail.com>2020-01-08 12:48:19 +0100
commit5b090b430d750961305030232314b6acdb0102aa (patch)
treee6085958e058d56aae448cfd0f0da1edc88c5589 /drivers/pwm
parentb8d74644f34a82a6dcd5f45d5bd57e64f1db0d4d (diff)
downloadlinux-5b090b430d750961305030232314b6acdb0102aa.tar.bz2
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>
Diffstat (limited to 'drivers/pwm')
-rw-r--r--drivers/pwm/pwm-sun4i.c23
1 files changed, 23 insertions, 0 deletions
diff --git a/drivers/pwm/pwm-sun4i.c b/drivers/pwm/pwm-sun4i.c
index 80026167044b..a6727dd89e28 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 %pe\n",
+ ERR_PTR(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;