[PATCH 1/9] phy: samsung: Add Exynos USB DRD PHY driver
Sam Protsenko
semen.protsenko at linaro.org
Thu Jul 10 00:29:18 CEST 2025
Add DM driver for Exynos USB PHY controllers. For now it only supports
Exynos850 SoC. Only UTMI+ (USB 2.0) PHY interface is implemented, as
Exynos850 doesn't support USB 3.0. Only two clocks are used for this
controller:
- phy: bus clock, used for PHY registers access
- ref: PHY reference clock (OSCCLK)
Ported from Linux kernel: drivers/phy/samsung/phy-exynos5-usbdrd.c
Signed-off-by: Sam Protsenko <semen.protsenko at linaro.org>
---
MAINTAINERS | 1 +
drivers/phy/Kconfig | 9 +
drivers/phy/Makefile | 1 +
drivers/phy/phy-exynos-usbdrd.c | 386 ++++++++++++++++++++++++++++++++
4 files changed, 397 insertions(+)
create mode 100644 drivers/phy/phy-exynos-usbdrd.c
diff --git a/MAINTAINERS b/MAINTAINERS
index d5264c8f5df6..fda0811d1500 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -602,6 +602,7 @@ ARM SAMSUNG EXYNOS850 SOC
M: Sam Protsenko <semen.protsenko at linaro.org>
S: Maintained
F: drivers/clk/exynos/clk-exynos850.c
+F: drivers/phy/phy-exynos-usbdrd.c
F: drivers/pinctrl/exynos/pinctrl-exynos850.c
ARM SAMSUNG SOC DRIVERS
diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
index d3fe90d939e8..c297fa03ea7f 100644
--- a/drivers/phy/Kconfig
+++ b/drivers/phy/Kconfig
@@ -259,6 +259,15 @@ config MT76X8_USB_PHY
This PHY is found on MT76x8 devices supporting USB.
+config PHY_EXYNOS_USBDRD
+ bool "Exynos SoC series USB DRD PHY driver"
+ depends on PHY && CLK
+ depends on ARCH_EXYNOS
+ select REGMAP
+ select SYSCON
+ help
+ Enable USB DRD PHY support for Exynos SoC series.
+
config PHY_MTK_TPHY
bool "MediaTek T-PHY Driver"
depends on PHY
diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
index b4d01fc700da..98c1ef8683b7 100644
--- a/drivers/phy/Makefile
+++ b/drivers/phy/Makefile
@@ -35,6 +35,7 @@ obj-$(CONFIG_KEYSTONE_USB_PHY) += keystone-usb-phy.o
obj-$(CONFIG_MT7620_USB_PHY) += mt7620-usb-phy.o
obj-$(CONFIG_MT76X8_USB_PHY) += mt76x8-usb-phy.o
obj-$(CONFIG_PHY_DA8XX_USB) += phy-da8xx-usb.o
+obj-$(CONFIG_PHY_EXYNOS_USBDRD) += phy-exynos-usbdrd.o
obj-$(CONFIG_PHY_MTK_TPHY) += phy-mtk-tphy.o
obj-$(CONFIG_PHY_NPCM_USB) += phy-npcm-usb.o
obj-$(CONFIG_PHY_IMX8MQ_USB) += phy-imx8mq-usb.o
diff --git a/drivers/phy/phy-exynos-usbdrd.c b/drivers/phy/phy-exynos-usbdrd.c
new file mode 100644
index 000000000000..db5815ed1840
--- /dev/null
+++ b/drivers/phy/phy-exynos-usbdrd.c
@@ -0,0 +1,386 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2025 Linaro Ltd.
+ * Sam Protsenko <semen.protsenko at linaro.org>
+ *
+ * Samsung Exynos SoC series USB DRD PHY driver.
+ * Based on Linux kernel PHY driver: drivers/phy/samsung/phy-exynos5-usbdrd.c
+ */
+
+#include <clk.h>
+#include <dm.h>
+#include <generic-phy.h>
+#include <regmap.h>
+#include <syscon.h>
+#include <asm/io.h>
+#include <dm/device_compat.h>
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/delay.h>
+
+/* Offset of PMU register controlling USB PHY output isolation */
+#define EXYNOS_USBDRD_PHY_CONTROL 0x0704
+#define EXYNOS_PHY_ENABLE BIT(0)
+
+/* Exynos USB PHY registers */
+#define EXYNOS5_FSEL_9MHZ6 0x0
+#define EXYNOS5_FSEL_10MHZ 0x1
+#define EXYNOS5_FSEL_12MHZ 0x2
+#define EXYNOS5_FSEL_19MHZ2 0x3
+#define EXYNOS5_FSEL_20MHZ 0x4
+#define EXYNOS5_FSEL_24MHZ 0x5
+#define EXYNOS5_FSEL_26MHZ 0x6
+#define EXYNOS5_FSEL_50MHZ 0x7
+
+/* Exynos850: USB DRD PHY registers */
+#define EXYNOS850_DRD_LINKCTRL 0x04
+#define LINKCTRL_FORCE_QACT BIT(8)
+#define LINKCTRL_BUS_FILTER_BYPASS GENMASK(7, 4)
+
+#define EXYNOS850_DRD_CLKRST 0x20
+#define CLKRST_LINK_SW_RST BIT(0)
+#define CLKRST_PORT_RST BIT(1)
+#define CLKRST_PHY_SW_RST BIT(3)
+
+#define EXYNOS850_DRD_SSPPLLCTL 0x30
+#define SSPPLLCTL_FSEL GENMASK(2, 0)
+
+#define EXYNOS850_DRD_UTMI 0x50
+#define UTMI_FORCE_SLEEP BIT(0)
+#define UTMI_FORCE_SUSPEND BIT(1)
+#define UTMI_DM_PULLDOWN BIT(2)
+#define UTMI_DP_PULLDOWN BIT(3)
+#define UTMI_FORCE_BVALID BIT(4)
+#define UTMI_FORCE_VBUSVALID BIT(5)
+
+#define EXYNOS850_DRD_HSP 0x54
+#define HSP_COMMONONN BIT(8)
+#define HSP_EN_UTMISUSPEND BIT(9)
+#define HSP_VBUSVLDEXT BIT(12)
+#define HSP_VBUSVLDEXTSEL BIT(13)
+#define HSP_FSV_OUT_EN BIT(24)
+
+#define EXYNOS850_DRD_HSP_TEST 0x5c
+#define HSP_TEST_SIDDQ BIT(24)
+
+#define KHZ 1000
+#define MHZ (KHZ * KHZ)
+
+/**
+ * struct exynos_usbdrd_phy - driver data for Exynos USB PHY
+ * @reg_phy: USB PHY controller register memory base
+ * @clk: clock for register access
+ * @core_clk: core clock for phy (ref clock)
+ * @reg_pmu: regmap for PMU block
+ * @extrefclk: frequency select settings when using 'separate reference clocks'
+ */
+struct exynos_usbdrd_phy {
+ void __iomem *reg_phy;
+ struct clk *clk;
+ struct clk *core_clk;
+ struct regmap *reg_pmu;
+ u32 extrefclk;
+};
+
+static void exynos_usbdrd_phy_isol(struct regmap *reg_pmu, bool isolate)
+{
+ unsigned int val;
+
+ if (!reg_pmu)
+ return;
+
+ val = isolate ? 0 : EXYNOS_PHY_ENABLE;
+ regmap_update_bits(reg_pmu, EXYNOS_USBDRD_PHY_CONTROL,
+ EXYNOS_PHY_ENABLE, val);
+}
+
+/*
+ * Convert the supplied clock rate to the value that can be written to the PHY
+ * register.
+ */
+static unsigned int exynos_rate_to_clk(unsigned long rate, u32 *reg)
+{
+ switch (rate) {
+ case 9600 * KHZ:
+ *reg = EXYNOS5_FSEL_9MHZ6;
+ break;
+ case 10 * MHZ:
+ *reg = EXYNOS5_FSEL_10MHZ;
+ break;
+ case 12 * MHZ:
+ *reg = EXYNOS5_FSEL_12MHZ;
+ break;
+ case 19200 * KHZ:
+ *reg = EXYNOS5_FSEL_19MHZ2;
+ break;
+ case 20 * MHZ:
+ *reg = EXYNOS5_FSEL_20MHZ;
+ break;
+ case 24 * MHZ:
+ *reg = EXYNOS5_FSEL_24MHZ;
+ break;
+ case 26 * MHZ:
+ *reg = EXYNOS5_FSEL_26MHZ;
+ break;
+ case 50 * MHZ:
+ *reg = EXYNOS5_FSEL_50MHZ;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static void exynos850_usbdrd_utmi_init(struct phy *phy)
+{
+ struct exynos_usbdrd_phy *phy_drd = dev_get_priv(phy->dev);
+ void __iomem *regs_base = phy_drd->reg_phy;
+ u32 reg;
+
+ /*
+ * Disable HWACG (hardware auto clock gating control). This will force
+ * QACTIVE signal in Q-Channel interface to HIGH level, to make sure
+ * the PHY clock is not gated by the hardware.
+ */
+ reg = readl(regs_base + EXYNOS850_DRD_LINKCTRL);
+ reg |= LINKCTRL_FORCE_QACT;
+ writel(reg, regs_base + EXYNOS850_DRD_LINKCTRL);
+
+ /* Start PHY Reset (POR=high) */
+ reg = readl(regs_base + EXYNOS850_DRD_CLKRST);
+ reg |= CLKRST_PHY_SW_RST;
+ writel(reg, regs_base + EXYNOS850_DRD_CLKRST);
+
+ /* Enable UTMI+ */
+ reg = readl(regs_base + EXYNOS850_DRD_UTMI);
+ reg &= ~(UTMI_FORCE_SUSPEND | UTMI_FORCE_SLEEP | UTMI_DP_PULLDOWN |
+ UTMI_DM_PULLDOWN);
+ writel(reg, regs_base + EXYNOS850_DRD_UTMI);
+
+ /* Set PHY clock and control HS PHY */
+ reg = readl(regs_base + EXYNOS850_DRD_HSP);
+ reg |= HSP_EN_UTMISUSPEND | HSP_COMMONONN;
+ writel(reg, regs_base + EXYNOS850_DRD_HSP);
+
+ /* Set VBUS Valid and D+ pull-up control by VBUS pad usage */
+ reg = readl(regs_base + EXYNOS850_DRD_LINKCTRL);
+ reg |= FIELD_PREP(LINKCTRL_BUS_FILTER_BYPASS, 0xf);
+ writel(reg, regs_base + EXYNOS850_DRD_LINKCTRL);
+
+ reg = readl(regs_base + EXYNOS850_DRD_UTMI);
+ reg |= UTMI_FORCE_BVALID | UTMI_FORCE_VBUSVALID;
+ writel(reg, regs_base + EXYNOS850_DRD_UTMI);
+
+ reg = readl(regs_base + EXYNOS850_DRD_HSP);
+ reg |= HSP_VBUSVLDEXT | HSP_VBUSVLDEXTSEL;
+ writel(reg, regs_base + EXYNOS850_DRD_HSP);
+
+ reg = readl(regs_base + EXYNOS850_DRD_SSPPLLCTL);
+ reg &= ~SSPPLLCTL_FSEL;
+ switch (phy_drd->extrefclk) {
+ case EXYNOS5_FSEL_50MHZ:
+ reg |= FIELD_PREP(SSPPLLCTL_FSEL, 7);
+ break;
+ case EXYNOS5_FSEL_26MHZ:
+ reg |= FIELD_PREP(SSPPLLCTL_FSEL, 6);
+ break;
+ case EXYNOS5_FSEL_24MHZ:
+ reg |= FIELD_PREP(SSPPLLCTL_FSEL, 2);
+ break;
+ case EXYNOS5_FSEL_20MHZ:
+ reg |= FIELD_PREP(SSPPLLCTL_FSEL, 1);
+ break;
+ case EXYNOS5_FSEL_19MHZ2:
+ reg |= FIELD_PREP(SSPPLLCTL_FSEL, 0);
+ break;
+ default:
+ dev_warn(phy->dev, "unsupported ref clk: %#.2x\n",
+ phy_drd->extrefclk);
+ break;
+ }
+ writel(reg, regs_base + EXYNOS850_DRD_SSPPLLCTL);
+
+ /* Power up PHY analog blocks */
+ reg = readl(regs_base + EXYNOS850_DRD_HSP_TEST);
+ reg &= ~HSP_TEST_SIDDQ;
+ writel(reg, regs_base + EXYNOS850_DRD_HSP_TEST);
+
+ /* Finish PHY reset (POR=low) */
+ udelay(10); /* required before doing POR=low */
+ reg = readl(regs_base + EXYNOS850_DRD_CLKRST);
+ reg &= ~(CLKRST_PHY_SW_RST | CLKRST_PORT_RST);
+ writel(reg, regs_base + EXYNOS850_DRD_CLKRST);
+ udelay(75); /* required after POR=low for guaranteed PHY clock */
+
+ /* Disable single ended signal out */
+ reg = readl(regs_base + EXYNOS850_DRD_HSP);
+ reg &= ~HSP_FSV_OUT_EN;
+ writel(reg, regs_base + EXYNOS850_DRD_HSP);
+}
+
+static void exynos850_usbdrd_utmi_exit(struct phy *phy)
+{
+ struct exynos_usbdrd_phy *phy_drd = dev_get_priv(phy->dev);
+ void __iomem *regs_base = phy_drd->reg_phy;
+ u32 reg;
+
+ /* Set PHY clock and control HS PHY */
+ reg = readl(regs_base + EXYNOS850_DRD_UTMI);
+ reg &= ~(UTMI_DP_PULLDOWN | UTMI_DM_PULLDOWN);
+ reg |= UTMI_FORCE_SUSPEND | UTMI_FORCE_SLEEP;
+ writel(reg, regs_base + EXYNOS850_DRD_UTMI);
+
+ /* Power down PHY analog blocks */
+ reg = readl(regs_base + EXYNOS850_DRD_HSP_TEST);
+ reg |= HSP_TEST_SIDDQ;
+ writel(reg, regs_base + EXYNOS850_DRD_HSP_TEST);
+
+ /* Link reset */
+ reg = readl(regs_base + EXYNOS850_DRD_CLKRST);
+ reg |= CLKRST_LINK_SW_RST;
+ writel(reg, regs_base + EXYNOS850_DRD_CLKRST);
+ udelay(10); /* required before doing POR=low */
+ reg &= ~CLKRST_LINK_SW_RST;
+ writel(reg, regs_base + EXYNOS850_DRD_CLKRST);
+}
+
+static int exynos_usbdrd_phy_init(struct phy *phy)
+{
+ struct exynos_usbdrd_phy *phy_drd = dev_get_priv(phy->dev);
+ int ret;
+
+ ret = clk_prepare_enable(phy_drd->clk);
+ if (ret)
+ return ret;
+
+ exynos850_usbdrd_utmi_init(phy);
+
+ clk_disable_unprepare(phy_drd->clk);
+
+ return 0;
+}
+
+static int exynos_usbdrd_phy_exit(struct phy *phy)
+{
+ struct exynos_usbdrd_phy *phy_drd = dev_get_priv(phy->dev);
+ int ret;
+
+ ret = clk_prepare_enable(phy_drd->clk);
+ if (ret)
+ return ret;
+
+ exynos850_usbdrd_utmi_exit(phy);
+
+ clk_disable_unprepare(phy_drd->clk);
+
+ return 0;
+}
+
+static int exynos_usbdrd_phy_power_on(struct phy *phy)
+{
+ struct exynos_usbdrd_phy *phy_drd = dev_get_priv(phy->dev);
+ int ret;
+
+ dev_dbg(phy->dev, "Request to power_on usbdrd_phy phy\n");
+
+ ret = clk_prepare_enable(phy_drd->core_clk);
+ if (ret)
+ return ret;
+
+ /* Power-on PHY */
+ exynos_usbdrd_phy_isol(phy_drd->reg_pmu, false);
+
+ return 0;
+}
+
+static int exynos_usbdrd_phy_power_off(struct phy *phy)
+{
+ struct exynos_usbdrd_phy *phy_drd = dev_get_priv(phy->dev);
+
+ dev_dbg(phy->dev, "Request to power_off usbdrd_phy phy\n");
+
+ /* Power-off the PHY */
+ exynos_usbdrd_phy_isol(phy_drd->reg_pmu, true);
+
+ clk_disable_unprepare(phy_drd->core_clk);
+
+ return 0;
+}
+
+static int exynos_usbdrd_phy_init_clk(struct udevice *dev)
+{
+ struct exynos_usbdrd_phy *phy_drd = dev_get_priv(dev);
+ unsigned long ref_rate;
+ int err;
+
+ phy_drd->clk = devm_clk_get(dev, "phy");
+ if (IS_ERR(phy_drd->clk)) {
+ err = PTR_ERR(phy_drd->clk);
+ dev_err(dev, "Failed to get phy clock (err=%d)\n", err);
+ return err;
+ }
+
+ phy_drd->core_clk = devm_clk_get(dev, "ref");
+ if (IS_ERR(phy_drd->core_clk)) {
+ err = PTR_ERR(phy_drd->core_clk);
+ dev_err(dev, "Failed to get ref clock (err=%d)\n", err);
+ return err;
+ }
+
+ ref_rate = clk_get_rate(phy_drd->core_clk);
+ err = exynos_rate_to_clk(ref_rate, &phy_drd->extrefclk);
+ if (err) {
+ dev_err(dev, "Clock rate %lu not supported\n", ref_rate);
+ return err;
+ }
+
+ return 0;
+}
+
+static int exynos_usbdrd_phy_probe(struct udevice *dev)
+{
+ struct exynos_usbdrd_phy *phy_drd = dev_get_priv(dev);
+ int err;
+
+ phy_drd->reg_phy = dev_read_addr_ptr(dev);
+ if (!phy_drd->reg_phy)
+ return -EINVAL;
+
+ err = exynos_usbdrd_phy_init_clk(dev);
+ if (err)
+ return err;
+
+ phy_drd->reg_pmu = syscon_regmap_lookup_by_phandle(dev,
+ "samsung,pmu-syscon");
+ if (IS_ERR(phy_drd->reg_pmu)) {
+ err = PTR_ERR(phy_drd->reg_pmu);
+ dev_err(dev, "Failed to lookup PMU regmap\n");
+ return err;
+ }
+
+ return 0;
+}
+
+static const struct phy_ops exynos_usbdrd_phy_ops = {
+ .init = exynos_usbdrd_phy_init,
+ .exit = exynos_usbdrd_phy_exit,
+ .power_on = exynos_usbdrd_phy_power_on,
+ .power_off = exynos_usbdrd_phy_power_off,
+};
+
+static const struct udevice_id exynos_usbdrd_phy_of_match[] = {
+ {
+ .compatible = "samsung,exynos850-usbdrd-phy",
+ },
+ { }
+};
+
+U_BOOT_DRIVER(exynos_usbdrd_phy) = {
+ .name = "exynos-usbdrd-phy",
+ .id = UCLASS_PHY,
+ .of_match = exynos_usbdrd_phy_of_match,
+ .probe = exynos_usbdrd_phy_probe,
+ .ops = &exynos_usbdrd_phy_ops,
+ .priv_auto = sizeof(struct exynos_usbdrd_phy),
+};
--
2.39.5
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