phy: mediatek: phy-mtk-hdmi: Register PHY provided regulator

At least version 2 of the HDMI PHY, found in MediaTek MT8195 and
MT8188 SoCs, does provide hardware support to switch on/off the
HDMI 5V pins (which are also used for DDC), and this translates
to this being a fixed regulator.

Register this PHY-provided regulator so that it can be fed to the
hdmi-connector driver to manage the HDMI +5V PWR rail.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20241120124143.132637-1-angelogioacchino.delregno@collabora.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

drivers/phy/mediatek/phy-mtk-hdmi-mt8195.c

@@ -9,6 +9,8 @@
 #include <linux/module.h>
 #include <linux/phy/phy.h>
 #include <linux/platform_device.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/of_regulator.h>
 #include <linux/types.h>
 #include <linux/units.h>
 #include <linux/nvmem-consumer.h>
@@ -478,8 +480,50 @@ static int mtk_hdmi_phy_configure(struct phy *phy, union phy_configure_opts *opt
 	return ret;
 }
 
+static int mtk_hdmi_phy_pwr5v_enable(struct regulator_dev *rdev)
+{
+	struct mtk_hdmi_phy *hdmi_phy = rdev_get_drvdata(rdev);
+
+	mtk_phy_set_bits(hdmi_phy->regs + HDMI_CTL_1, RG_HDMITX_PWR5V_O);
+
+	return 0;
+}
+
+static int mtk_hdmi_phy_pwr5v_disable(struct regulator_dev *rdev)
+{
+	struct mtk_hdmi_phy *hdmi_phy = rdev_get_drvdata(rdev);
+
+	mtk_phy_clear_bits(hdmi_phy->regs + HDMI_CTL_1, RG_HDMITX_PWR5V_O);
+
+	return 0;
+}
+
+static int mtk_hdmi_phy_pwr5v_is_enabled(struct regulator_dev *rdev)
+{
+	struct mtk_hdmi_phy *hdmi_phy = rdev_get_drvdata(rdev);
+
+	return !!(readl(hdmi_phy->regs + HDMI_CTL_1) & RG_HDMITX_PWR5V_O);
+}
+
+static const struct regulator_ops mtk_hdmi_pwr5v_regulator_ops = {
+	.enable = mtk_hdmi_phy_pwr5v_enable,
+	.disable = mtk_hdmi_phy_pwr5v_disable,
+	.is_enabled = mtk_hdmi_phy_pwr5v_is_enabled
+};
+
+static const struct regulator_desc mtk_hdmi_phy_pwr5v_desc = {
+	.name = "hdmi-pwr5v",
+	.id = -1,
+	.n_voltages = 1,
+	.fixed_uV = 5000000,
+	.ops = &mtk_hdmi_pwr5v_regulator_ops,
+	.type = REGULATOR_VOLTAGE,
+	.owner = THIS_MODULE,
+};
+
 struct mtk_hdmi_phy_conf mtk_hdmi_phy_8195_conf = {
 	.flags = CLK_SET_RATE_PARENT | CLK_SET_RATE_GATE,
+	.hdmi_phy_regulator_desc = &mtk_hdmi_phy_pwr5v_desc,
 	.hdmi_phy_clk_ops = &mtk_hdmi_pll_ops,
 	.hdmi_phy_enable_tmds = mtk_hdmi_phy_enable_tmds,
 	.hdmi_phy_disable_tmds = mtk_hdmi_phy_disable_tmds,

drivers/phy/mediatek/phy-mtk-hdmi-mt8195.h

@@ -103,6 +103,9 @@
 #define HDMI_ANA_CTL 0x7c
 #define REG_ANA_HDMI20_FIFO_EN BIT(16)
 
+#define HDMI_CTL_1 0xc4
+#define RG_HDMITX_PWR5V_O BIT(9)
+
 #define HDMI_CTL_3 0xcc
 #define REG_HDMITXPLL_DIV GENMASK(4, 0)
 #define REG_HDMITX_REF_XTAL_SEL BIT(7)

drivers/phy/mediatek/phy-mtk-hdmi.c

@@ -75,6 +75,28 @@ static void mtk_hdmi_phy_clk_get_data(struct mtk_hdmi_phy *hdmi_phy,
 	clk_init->ops = hdmi_phy->conf->hdmi_phy_clk_ops;
 }
 
+static int mtk_hdmi_phy_register_regulators(struct mtk_hdmi_phy *hdmi_phy)
+{
+	const struct regulator_desc *vreg_desc = hdmi_phy->conf->hdmi_phy_regulator_desc;
+	const struct regulator_init_data vreg_init_data = {
+		.constraints = {
+			.valid_ops_mask = REGULATOR_CHANGE_STATUS,
+		}
+	};
+	struct regulator_config vreg_config = {
+		.dev = hdmi_phy->dev,
+		.driver_data = hdmi_phy,
+		.init_data = &vreg_init_data,
+		.of_node = hdmi_phy->dev->of_node
+	};
+
+	hdmi_phy->rdev = devm_regulator_register(hdmi_phy->dev, vreg_desc, &vreg_config);
+	if (IS_ERR(hdmi_phy->rdev))
+		return PTR_ERR(hdmi_phy->rdev);
+
+	return 0;
+}
+
 static int mtk_hdmi_phy_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -150,6 +172,12 @@ static int mtk_hdmi_phy_probe(struct platform_device *pdev)
 	if (hdmi_phy->conf->pll_default_off)
 		hdmi_phy->conf->hdmi_phy_disable_tmds(hdmi_phy);
 
+	if (hdmi_phy->conf->hdmi_phy_regulator_desc) {
+		ret = mtk_hdmi_phy_register_regulators(hdmi_phy);
+		if (ret)
+			return ret;
+	}
+
 	return of_clk_add_provider(dev->of_node, of_clk_src_simple_get,
 				   hdmi_phy->pll);
 }

drivers/phy/mediatek/phy-mtk-hdmi.h

@@ -13,6 +13,8 @@
 #include <linux/module.h>
 #include <linux/phy/phy.h>
 #include <linux/platform_device.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/machine.h>
 #include <linux/types.h>
 
 struct mtk_hdmi_phy;
@@ -20,6 +22,7 @@ struct mtk_hdmi_phy;
 struct mtk_hdmi_phy_conf {
 	unsigned long flags;
 	bool pll_default_off;
+	const struct regulator_desc *hdmi_phy_regulator_desc;
 	const struct clk_ops *hdmi_phy_clk_ops;
 	void (*hdmi_phy_enable_tmds)(struct mtk_hdmi_phy *hdmi_phy);
 	void (*hdmi_phy_disable_tmds)(struct mtk_hdmi_phy *hdmi_phy);
@@ -32,6 +35,7 @@ struct mtk_hdmi_phy {
 	struct mtk_hdmi_phy_conf *conf;
 	struct clk *pll;
 	struct clk_hw pll_hw;
+	struct regulator_dev *rdev;
 	unsigned long pll_rate;
 	unsigned char drv_imp_clk;
 	unsigned char drv_imp_d2;