[U-Boot] [PATCH 30/48] stm32mp1: board: enable v1v2_hdmi and v3v3_hdmi regulator on dk2 boot

[Patrick Delaunay]

As for Audio codec IC, HDMI IC is not "IO safe".
HDMI regulators (v3v3 and v1v2) must be enabled to allow
I2C1 bus usage. HDMI IC must be under reset during power up
and keep HDMI and AUDIO devices in reset while they are not
used in U-Boot to keep them in low power mode
(each device can be kept in reset independently keeping their
power supplies ON until kernel).

Signed-off-by: Patrice Chotard <patrice.chotard at st.com>
Signed-off-by: Patrick Delaunay <patrick.delaunay at st.com>
---

 arch/arm/dts/stm32mp157c-dk2-u-boot.dtsi |  6 +++
 board/st/stm32mp1/Kconfig                |  4 ++
 board/st/stm32mp1/stm32mp1.c             | 70 ++++++++++++++++++++++++++++++++
 3 files changed, 80 insertions(+)

diff --git a/arch/arm/dts/stm32mp157c-dk2-u-boot.dtsi b/arch/arm/dts/stm32mp157c-dk2-u-boot.dtsi
index 06ef3a4..18ac1e3 100644
--- a/arch/arm/dts/stm32mp157c-dk2-u-boot.dtsi
+++ b/arch/arm/dts/stm32mp157c-dk2-u-boot.dtsi
@@ -4,3 +4,9 @@
  */
 
 #include "stm32mp157a-dk1-u-boot.dtsi"
+
+&i2c1 {
+	hdmi-transmitter at 39 {
+		reset-gpios = <&gpioa 10 GPIO_ACTIVE_LOW>;
+	};
+};
diff --git a/board/st/stm32mp1/Kconfig b/board/st/stm32mp1/Kconfig
index 87216c0..4fa2360 100644
--- a/board/st/stm32mp1/Kconfig
+++ b/board/st/stm32mp1/Kconfig
@@ -22,4 +22,8 @@ config CMD_STBOARD
 	  This compile the stboard command to
 	  read and write the board in the OTP.
 
+config TARGET_STM32MP157C_DK2
+	bool "support of STMicroelectronics STM32MP157C-DK2 Discovery Board"
+	default y
+
 endif
diff --git a/board/st/stm32mp1/stm32mp1.c b/board/st/stm32mp1/stm32mp1.c
index ad3db31..2837e9a 100644
--- a/board/st/stm32mp1/stm32mp1.c
+++ b/board/st/stm32mp1/stm32mp1.c
@@ -504,6 +504,73 @@ static void sysconf_init(void)
 #endif
 }
 
+#ifdef CONFIG_DM_REGULATOR
+/* Fix to make I2C1 usable on DK2 for touchscreen usage in kernel */
+static int dk2_i2c1_fix(void)
+{
+	ofnode node;
+	struct gpio_desc hdmi, audio;
+	int ret = 0;
+
+	node = ofnode_path("/soc/i2c at 40012000/hdmi-transmitter at 39");
+	if (!ofnode_valid(node)) {
+		pr_debug("%s: no hdmi-transmitter at 39 ?\n", __func__);
+		return -ENOENT;
+	}
+
+	if (gpio_request_by_name_nodev(node, "reset-gpios", 0,
+				       &hdmi, GPIOD_IS_OUT)) {
+		pr_debug("%s: could not find reset-gpios\n",
+			 __func__);
+		return -ENOENT;
+	}
+
+	node = ofnode_path("/soc/i2c at 40012000/cs42l51 at 4a");
+	if (!ofnode_valid(node)) {
+		pr_debug("%s: no cs42l51 at 4a ?\n", __func__);
+		return -ENOENT;
+	}
+
+	if (gpio_request_by_name_nodev(node, "reset-gpios", 0,
+				       &audio, GPIOD_IS_OUT)) {
+		pr_debug("%s: could not find reset-gpios\n",
+			 __func__);
+		return -ENOENT;
+	}
+
+	/* before power up, insure that HDMI and AUDIO IC is under reset */
+	ret = dm_gpio_set_value(&hdmi, 1);
+	if (ret) {
+		pr_err("%s: can't set_value for hdmi_nrst gpio", __func__);
+		goto error;
+	}
+	ret = dm_gpio_set_value(&audio, 1);
+	if (ret) {
+		pr_err("%s: can't set_value for audio_nrst gpio", __func__);
+		goto error;
+	}
+
+	/* power-up audio IC */
+	regulator_autoset_by_name("v1v8_audio", NULL);
+
+	/* power-up HDMI IC */
+	regulator_autoset_by_name("v1v2_hdmi", NULL);
+	regulator_autoset_by_name("v3v3_hdmi", NULL);
+
+error:
+	return ret;
+}
+
+static bool board_is_dk2(void)
+{
+	if (CONFIG_IS_ENABLED(TARGET_STM32MP157C_DK2) &&
+	    of_machine_is_compatible("st,stm32mp157c-dk2"))
+		return true;
+
+	return false;
+}
+#endif
+
 /* board dependent setup after realloc */
 int board_init(void)
 {
@@ -522,6 +589,9 @@ int board_init(void)
 	board_key_check();
 
 #ifdef CONFIG_DM_REGULATOR
+	if (board_is_dk2())
+		dk2_i2c1_fix();
+
 	regulators_enable_boot_on(_DEBUG);
 #endif
 
-- 
2.7.4