[PATCH v2 1/1] clk: clk-gpio: add actual gated clock

[Marek Vasut]

On 12/16/23 17:56, Sean Anderson wrote:
> On 12/16/23 11:52, Marek Vasut wrote:
>> On 12/16/23 16:37, Sean Anderson wrote:
>>> On 12/16/23 03:48, Svyatoslav Ryhel wrote:
>>>> Existing gpio-gate-clock driver acts like a simple GPIO switch 
>>>> without any
>>>> effect on gated clock. Add actual clock actions into enable/disable 
>>>> ops and
>>>> implement get_rate op by passing gated clock if it is enabled.
>>>>
>>>> Signed-off-by: Svyatoslav Ryhel <clamor95 at gmail.com>
>>>> ---
>>>>   drivers/clk/clk-gpio.c | 44 
>>>> ++++++++++++++++++++++++++++++++++--------
>>>>   1 file changed, 36 insertions(+), 8 deletions(-)
>>>>
>>>> diff --git a/drivers/clk/clk-gpio.c b/drivers/clk/clk-gpio.c
>>>> index 26d795b978..72d9747a47 100644
>>>> --- a/drivers/clk/clk-gpio.c
>>>> +++ b/drivers/clk/clk-gpio.c
>>>> @@ -3,19 +3,23 @@
>>>>    * Copyright (C) 2023 Marek Vasut <marek.vasut+renesas at mailbox.org>
>>>>    */
>>>> -#include <asm/gpio.h>
>>>> -#include <common.h>
>>>> -#include <clk-uclass.h>
>>>> +#include <clk.h>
>>>>   #include <dm.h>
>>>> +#include <clk-uclass.h>
>>>> +#include <linux/clk-provider.h>
>>>> +
>>>> +#include <asm/gpio.h>
>>>>   struct clk_gpio_priv {
>>>> -    struct gpio_desc    enable;
>>>> +    struct gpio_desc    enable;    /* GPIO, controlling the gate */
>>>> +    struct clk        *clk;    /* Gated clock */
>>>>   };
>>>>   static int clk_gpio_enable(struct clk *clk)
>>>>   {
>>>>       struct clk_gpio_priv *priv = dev_get_priv(clk->dev);
>>>> +    clk_enable(priv->clk);
>>>>       dm_gpio_set_value(&priv->enable, 1);
>>>>       return 0;
>>>> @@ -26,21 +30,45 @@ static int clk_gpio_disable(struct clk *clk)
>>>>       struct clk_gpio_priv *priv = dev_get_priv(clk->dev);
>>>>       dm_gpio_set_value(&priv->enable, 0);
>>>> +    clk_disable(priv->clk);
>>>>       return 0;
>>>>   }
>>>> +static ulong clk_gpio_get_rate(struct clk *clk)
>>>> +{
>>>> +    struct clk_gpio_priv *priv = dev_get_priv(clk->dev);
>>>> +
>>>> +    return clk_get_rate(priv->clk);
>>>> +}
>>>> +
>>>>   const struct clk_ops clk_gpio_ops = {
>>>>       .enable        = clk_gpio_enable,
>>>>       .disable    = clk_gpio_disable,
>>>> +    .get_rate    = clk_gpio_get_rate,
>>>>   };
>>>> -static int clk_gpio_probe(struct udevice *dev)
>>>> +static int clk_gpio_of_to_plat(struct udevice *dev)
>>>>   {
>>>>       struct clk_gpio_priv *priv = dev_get_priv(dev);
>>>> +    int ret;
>>>> -    return gpio_request_by_name(dev, "enable-gpios", 0,
>>>> -                    &priv->enable, GPIOD_IS_OUT);
>>>> +    priv->clk = devm_clk_get(dev, NULL);
>>>> +    if (IS_ERR(priv->clk)) {
>>>> +        log_debug("%s: Could not get gated clock: %ld\n",
>>>> +              __func__, PTR_ERR(priv->clk));
>>>> +        return PTR_ERR(priv->clk);
>>>> +    }
>>>> +
>>>> +    ret = gpio_request_by_name(dev, "enable-gpios", 0,
>>>> +                   &priv->enable, GPIOD_IS_OUT);
>>>> +    if (ret) {
>>>> +        log_debug("%s: Could not decode enable-gpios (%d)\n",
>>>> +              __func__, ret);
>>>> +        return ret;
>>>> +    }
>>>> +
>>>> +    return 0;
>>
>> All this forwarding of clock enable/disable/get_rate for parent clock 
>> should already be done in clock core. If it is not, then it should be 
>> fixed in clock core.
> 
> Only CCF forwards things. It's up to the driver to do it in the non-CCF 
> case.

Shall we add dependency on CCF instead of duplicating code in drivers ?