[PATCH V3 RESEND] pwm: meson: add pwm support for S4
Junyi Zhao
junyi.zhao at amlogic.com
Fri Oct 27 02:22:21 PDT 2023
Hello YiXun,
CLK config has been separated on HW. No more in pwmchip.
And s4 datasheet about clk updated already.
On 2023/10/24 3:40, George Stark wrote:
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>
> Hello Yixun Lan
>
> On 10/17/23 01:37, Yixun Lan wrote:
>> Hi JunYi
>>
>> On 13:24 Mon 16 Oct , JunYi Zhao wrote:
>>> 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);
>> use devm_clk_get_optional() which would save you from introducing
>> the 'extern_clk' variable
>
> On S4 and other recent chips PWM clock resides in separate IP and it
> must be provided to driver in order to control PWM frequency. So this
> clock is not optional.
>
>>
>>> + 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
>>>
>>>
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>>> linux-amlogic at lists.infradead.org
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>>
>
> --
> Best regards
> George
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