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

[Christoph Muellner]

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>
---
 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)
+{
+	int ret;
+	struct udevice *pinctrl;
+
+	ret = uclass_get_device(UCLASS_PINCTRL, 0, &pinctrl);
+	if (ret) {
+		debug("%s: Cannot find pinctrl device\n", __func__);
+		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__);
+		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;
+	}
+
+out:
 	return 0;
 }
 
-- 
2.11.0