[U-Boot] [PATCH 4/4] rockchip: puma-rk3399: Enable vdd-log during bootup.

[Philipp Tomsich]

> On 06.12.2018, at 12:25, Christoph Muellner <christoph.muellner at theobroma-systems.com> wrote:
> 
> On the RK3399-Q7 "Puma" module VDD_LOG is generated by an external
> regulator, which sets the voltage level to 900 mV, which is within
> the allowed range and which works quite fine.
> 
> However, in specific use-cases we need to adjust VDD_LOG to
> maintain stable operation or to reduce power consumption.
> This adjustment can be done via pwm2.
> 
> This patch allows to tune the VDD_LOG voltage level
> via DTS. To do so the following things are done:
> 
> * Setup pin muxing for PWM2 (based on DTS settings)
> * Turn on the vdd_log regulator (based on DTS settings)
> 
> Reported-by: Assaf Agmon <assaf at r-go.io>
> Signed-off-by: Philipp Tomsich <philipp.tomsich at theobroma-systems.com>
> Signed-off-by: Christoph Muellner <christoph.muellner at theobroma-systems.com>

Reviewed-by: Philipp Tomsich <philipp.tomsich at theobroma-systems.com>

See below for requested changes.

> ---
> board/theobroma-systems/puma_rk3399/puma-rk3399.c | 43 +++++++++++++++++++++++
> 1 file changed, 43 insertions(+)
> 
> diff --git a/board/theobroma-systems/puma_rk3399/puma-rk3399.c b/board/theobroma-systems/puma_rk3399/puma-rk3399.c
> index 573e691457f..e2915fcca50 100644
> --- a/board/theobroma-systems/puma_rk3399/puma-rk3399.c
> +++ b/board/theobroma-systems/puma_rk3399/puma-rk3399.c
> @@ -23,10 +23,34 @@
> #include <power/regulator.h>
> #include <u-boot/sha256.h>
> 
> +static int setup_pinctrl(void)

I’d prefer a forward-declaration and this further down, as I want to keep board_init()
up front.  Just a personal preference, but still ...

> +{
> +	int ret;
> +	struct udevice *pinctrl;
> +
> +	ret = uclass_get_device(UCLASS_PINCTRL, 0, &pinctrl);
> +	if (ret) {
> +		debug("%s: Cannot find pinctrl device\n", __func__);

Please use pr_debug.

> +		goto out;
> +	}
> +
> +	/* Enable pwm2 for vdd_log regulator. */
> +	ret = pinctrl_request_noflags(pinctrl, PERIPH_ID_PWM2);
> +	if (ret) {
> +		printf("%s PWM2 pinctrl init fail!\n", __func__);

Don’t use printf here — either this is a pr_err or a pr_debug.

> +		goto out;
> +	}
> +
> +out:
> +	return 0;
> +}
> +
> int board_init(void)
> {
> 	int ret;
> 
> +	setup_pinctrl();
> +
> 	/*
> 	 * We need to call into regulators_enable_boot_on() again, as the call
> 	 * during SPL may have not included all regulators.
> @@ -35,6 +59,25 @@ int board_init(void)
> 	if (ret)
> 		debug("%s: Cannot enable boot on regulator\n", __func__);
> 
> +	/*
> +	 * vdd_log is ignored by regulators_enable_boot_on(), because
> +	 * regulator-min-microvolt != regulator-max-microvolt.
> +	 * Therefore we explicitly enable it here.
> +	 */
> +	struct udevice *regulator;
> +	ret = regulator_get_by_platname("vdd_log", &regulator);
> +	if (ret) {
> +		debug("%s Looking up regulator vdd-log failed!\n", __func__);
> +		goto out;
> +	}
> +
> +	ret = regulator_set_enable(regulator, true);
>  +	if (ret) {
> +		debug("%s Enabling vdd-log failed!\n", __func__);
> +		goto out;
> +	}

Generally speaking: I would prefer a
	if (ret == 0)
		ret = regulator_set_enable(regulator, true);
	if (ret)
		pr_debug(…)	

However, this should be irrelevant anyway: why doesn’t 
	ret = regulators_enable_boot_on(false); 
in board_init() suffice?

> +
> +out:
> 	return 0;
> }
> 
> -- 
> 2.11.0
>