[PATCH] [v3] pwm: meson: add pwm support for S4

[JunYi Zhao]

From: "junyi.zhao" <junyi.zhao at amlogic.com>

Support PWM for S4 soc.
Now the PWM clock input is done in independent CLKCTRL registers.
And no more in the PWM registers.
PWM needs to obtain an external clock source.

Signed-off-by: junyi.zhao <junyi.zhao at amlogic.com>
---
V2 -> V3: 
Rebase and Review the latest upstream code again.
After reconstruction, stick to the previous code as much as possible.
 drivers/pwm/pwm-meson.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/drivers/pwm/pwm-meson.c b/drivers/pwm/pwm-meson.c
index 25519cddc2a9..fe9fd75747c4 100644
--- a/drivers/pwm/pwm-meson.c
+++ b/drivers/pwm/pwm-meson.c
@@ -99,6 +99,7 @@ struct meson_pwm_channel {
 struct meson_pwm_data {
 	const char * const *parent_names;
 	unsigned int num_parents;
+	unsigned int extern_clk;
 };
 
 struct meson_pwm {
@@ -396,6 +397,10 @@ static const struct meson_pwm_data pwm_g12a_ao_cd_data = {
 	.num_parents = ARRAY_SIZE(pwm_g12a_ao_cd_parent_names),
 };
 
+static const struct meson_pwm_data pwm_s4_data = {
+	.extern_clk = true,
+};
+
 static const struct of_device_id meson_pwm_matches[] = {
 	{
 		.compatible = "amlogic,meson8b-pwm",
@@ -429,6 +434,10 @@ static const struct of_device_id meson_pwm_matches[] = {
 		.compatible = "amlogic,meson-g12a-ao-pwm-cd",
 		.data = &pwm_g12a_ao_cd_data
 	},
+	{
+		.compatible = "amlogic,s4-pwm",
+		.data = &pwm_s4_data,
+	},
 	{},
 };
 MODULE_DEVICE_TABLE(of, meson_pwm_matches);
@@ -451,6 +460,16 @@ static int meson_pwm_init_channels(struct meson_pwm *meson)
 		struct clk_parent_data div_parent = {}, gate_parent = {};
 		struct clk_init_data init = {};
 
+		if (meson->data->extern_clk) {
+			snprintf(name, sizeof(name), "clkin%u", i);
+			channel->clk = devm_clk_get(dev, name);
+			if (IS_ERR(channel->clk)) {
+				dev_err(meson->chip.dev, "can't get device clock\n");
+				return PTR_ERR(channel->clk);
+			}
+			continue;
+		}
+
 		snprintf(name, sizeof(name), "%s#mux%u", dev_name(dev), i);
 
 		init.name = name;

base-commit: 4d2c646ac07cf4a35ef1c4a935a1a4fd6c6b1a36
-- 
2.41.0