phy: add support for STM32 usb phy controller

This patch adds phy tranceiver driver for STM32 USB PHY
Controller (usbphyc) that provides dual port High-Speed
phy for OTG (single port) and EHCI/OHCI host controller
(two ports).
One port of the phy is shared between the two USB controllers
through a UTMI+ switch.

Signed-off-by: Christophe Kerello <christophe.kerello@st.com>
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>

3 files changed, 416 insertions, 0 deletions

diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
index 119edec..8fc2295 100644
--- a/drivers/phy/Kconfig
+++ b/drivers/phy/Kconfig
@@ -110,6 +110,19 @@ config STI_USB_PHY
 	  used by USB2 and USB3 Host controllers available on
 	  STiH407 SoC families.
 
+config PHY_STM32_USBPHYC
+	tristate "STMicroelectronics STM32 SoC USB HS PHY driver"
+	depends on PHY && ARCH_STM32MP
+	help
+	  Enable this to support the High-Speed USB transceiver that is part of
+	  STMicroelectronics STM32 SoCs.
+
+	  This driver controls the entire USB PHY block: the USB PHY controller
+	  (USBPHYC) and the two 8-bit wide UTMI+ interface. First interface is
+	  used by an HS USB Host controller, and the second one is shared
+	  between an HS USB OTG controller and an HS USB Host controller,
+	  selected by an USB switch.
+
 config MESON_GXL_USB_PHY
 	bool "Amlogic Meson GXL USB PHYs"
 	depends on PHY && ARCH_MESON && MESON_GXL
diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
index 5c8711d..ba0803c 100644
--- a/drivers/phy/Makefile
+++ b/drivers/phy/Makefile
@@ -12,4 +12,5 @@ obj-$(CONFIG_BCM6368_USBH_PHY) += bcm6368-usbh-phy.o
 obj-$(CONFIG_PHY_SANDBOX) += sandbox-phy.o
 obj-$(CONFIG_$(SPL_)PIPE3_PHY) += ti-pipe3-phy.o
 obj-$(CONFIG_STI_USB_PHY) += sti_usb_phy.o
+obj-$(CONFIG_PHY_STM32_USBPHYC) += phy-stm32-usbphyc.o
 obj-$(CONFIG_MESON_GXL_USB_PHY) += meson-gxl-usb2.o meson-gxl-usb3.o
diff --git a/drivers/phy/phy-stm32-usbphyc.c b/drivers/phy/phy-stm32-usbphyc.c
new file mode 100644
index 0000000..4ff6a9a
--- /dev/null
+++ b/drivers/phy/phy-stm32-usbphyc.c
@@ -0,0 +1,402 @@
+// SPDX-License-Identifier:	GPL-2.0+	BSD-3-Clause
+/*
+ * Copyright (C) 2018, STMicroelectronics - All Rights Reserved
+ */
+
+#include <common.h>
+#include <clk.h>
+#include <div64.h>
+#include <dm.h>
+#include <fdtdec.h>
+#include <generic-phy.h>
+#include <reset.h>
+#include <syscon.h>
+#include <usb.h>
+#include <asm/io.h>
+#include <linux/bitops.h>
+#include <power/regulator.h>
+
+/* USBPHYC registers */
+#define STM32_USBPHYC_PLL	0x0
+#define STM32_USBPHYC_MISC	0x8
+
+/* STM32_USBPHYC_PLL bit fields */
+#define PLLNDIV			GENMASK(6, 0)
+#define PLLNDIV_SHIFT		0
+#define PLLFRACIN		GENMASK(25, 10)
+#define PLLFRACIN_SHIFT		10
+#define PLLEN			BIT(26)
+#define PLLSTRB			BIT(27)
+#define PLLSTRBYP		BIT(28)
+#define PLLFRACCTL		BIT(29)
+#define PLLDITHEN0		BIT(30)
+#define PLLDITHEN1		BIT(31)
+
+/* STM32_USBPHYC_MISC bit fields */
+#define SWITHOST		BIT(0)
+
+#define MAX_PHYS		2
+
+#define PLL_LOCK_TIME_US	100
+#define PLL_PWR_DOWN_TIME_US	5
+#define PLL_FVCO		2880	 /* in MHz */
+#define PLL_INFF_MIN_RATE	19200000 /* in Hz */
+#define PLL_INFF_MAX_RATE	38400000 /* in Hz */
+
+struct pll_params {
+	u8 ndiv;
+	u16 frac;
+};
+
+struct stm32_usbphyc {
+	fdt_addr_t base;
+	struct clk clk;
+	struct stm32_usbphyc_phy {
+		struct udevice *vdd;
+		struct udevice *vdda1v1;
+		struct udevice *vdda1v8;
+		int index;
+		bool init;
+		bool powered;
+	} phys[MAX_PHYS];
+};
+
+void stm32_usbphyc_get_pll_params(u32 clk_rate, struct pll_params *pll_params)
+{
+	unsigned long long fvco, ndiv, frac;
+
+	/*
+	 *    | FVCO = INFF*2*(NDIV + FRACT/2^16 ) when DITHER_DISABLE[1] = 1
+	 *    | FVCO = 2880MHz
+	 *    | NDIV = integer part of input bits to set the LDF
+	 *    | FRACT = fractional part of input bits to set the LDF
+	 *  =>	PLLNDIV = integer part of (FVCO / (INFF*2))
+	 *  =>	PLLFRACIN = fractional part of(FVCO / INFF*2) * 2^16
+	 * <=>  PLLFRACIN = ((FVCO / (INFF*2)) - PLLNDIV) * 2^16
+	 */
+	fvco = (unsigned long long)PLL_FVCO * 1000000; /* In Hz */
+
+	ndiv = fvco;
+	do_div(ndiv, (clk_rate * 2));
+	pll_params->ndiv = (u8)ndiv;
+
+	frac = fvco * (1 << 16);
+	do_div(frac, (clk_rate * 2));
+	frac = frac - (ndiv * (1 << 16));
+	pll_params->frac = (u16)frac;
+}
+
+static int stm32_usbphyc_pll_init(struct stm32_usbphyc *usbphyc)
+{
+	struct pll_params pll_params;
+	u32 clk_rate = clk_get_rate(&usbphyc->clk);
+	u32 usbphyc_pll;
+
+	if ((clk_rate < PLL_INFF_MIN_RATE) || (clk_rate > PLL_INFF_MAX_RATE)) {
+		pr_debug("%s: input clk freq (%dHz) out of range\n",
+			 __func__, clk_rate);
+		return -EINVAL;
+	}
+
+	stm32_usbphyc_get_pll_params(clk_rate, &pll_params);
+
+	usbphyc_pll = PLLDITHEN1 | PLLDITHEN0 | PLLSTRBYP;
+	usbphyc_pll |= ((pll_params.ndiv << PLLNDIV_SHIFT) & PLLNDIV);
+
+	if (pll_params.frac) {
+		usbphyc_pll |= PLLFRACCTL;
+		usbphyc_pll |= ((pll_params.frac << PLLFRACIN_SHIFT)
+				 & PLLFRACIN);
+	}
+
+	writel(usbphyc_pll, usbphyc->base + STM32_USBPHYC_PLL);
+
+	pr_debug("%s: input clk freq=%dHz, ndiv=%d, frac=%d\n", __func__,
+		 clk_rate, pll_params.ndiv, pll_params.frac);
+
+	return 0;
+}
+
+static bool stm32_usbphyc_is_init(struct stm32_usbphyc *usbphyc)
+{
+	int i;
+
+	for (i = 0; i < MAX_PHYS; i++) {
+		if (usbphyc->phys[i].init)
+			return true;
+	}
+
+	return false;
+}
+
+static bool stm32_usbphyc_is_powered(struct stm32_usbphyc *usbphyc)
+{
+	int i;
+
+	for (i = 0; i < MAX_PHYS; i++) {
+		if (usbphyc->phys[i].powered)
+			return true;
+	}
+
+	return false;
+}
+
+static int stm32_usbphyc_phy_init(struct phy *phy)
+{
+	struct stm32_usbphyc *usbphyc = dev_get_priv(phy->dev);
+	struct stm32_usbphyc_phy *usbphyc_phy = usbphyc->phys + phy->id;
+	bool pllen = readl(usbphyc->base + STM32_USBPHYC_PLL) & PLLEN ?
+		     true : false;
+	int ret;
+
+	pr_debug("%s phy ID = %lu\n", __func__, phy->id);
+	/* Check if one phy port has already configured the pll */
+	if (pllen && stm32_usbphyc_is_init(usbphyc))
+		goto initialized;
+
+	if (pllen) {
+		clrbits_le32(usbphyc->base + STM32_USBPHYC_PLL, PLLEN);
+		udelay(PLL_PWR_DOWN_TIME_US);
+	}
+
+	ret = stm32_usbphyc_pll_init(usbphyc);
+	if (ret)
+		return ret;
+
+	setbits_le32(usbphyc->base + STM32_USBPHYC_PLL, PLLEN);
+
+	/*
+	 * We must wait PLL_LOCK_TIME_US before checking that PLLEN
+	 * bit is still set
+	 */
+	udelay(PLL_LOCK_TIME_US);
+
+	if (!(readl(usbphyc->base + STM32_USBPHYC_PLL) & PLLEN))
+		return -EIO;
+
+initialized:
+	usbphyc_phy->init = true;
+
+	return 0;
+}
+
+static int stm32_usbphyc_phy_exit(struct phy *phy)
+{
+	struct stm32_usbphyc *usbphyc = dev_get_priv(phy->dev);
+	struct stm32_usbphyc_phy *usbphyc_phy = usbphyc->phys + phy->id;
+
+	pr_debug("%s phy ID = %lu\n", __func__, phy->id);
+	usbphyc_phy->init = false;
+
+	/* Check if other phy port requires pllen */
+	if (stm32_usbphyc_is_init(usbphyc))
+		return 0;
+
+	clrbits_le32(usbphyc->base + STM32_USBPHYC_PLL, PLLEN);
+
+	/*
+	 * We must wait PLL_PWR_DOWN_TIME_US before checking that PLLEN
+	 * bit is still clear
+	 */
+	udelay(PLL_PWR_DOWN_TIME_US);
+
+	if (readl(usbphyc->base + STM32_USBPHYC_PLL) & PLLEN)
+		return -EIO;
+
+	return 0;
+}
+
+static int stm32_usbphyc_phy_power_on(struct phy *phy)
+{
+	struct stm32_usbphyc *usbphyc = dev_get_priv(phy->dev);
+	struct stm32_usbphyc_phy *usbphyc_phy = usbphyc->phys + phy->id;
+	int ret;
+
+	pr_debug("%s phy ID = %lu\n", __func__, phy->id);
+	if (usbphyc_phy->vdda1v1) {
+		ret = regulator_set_enable(usbphyc_phy->vdda1v1, true);
+		if (ret)
+			return ret;
+	}
+
+	if (usbphyc_phy->vdda1v8) {
+		ret = regulator_set_enable(usbphyc_phy->vdda1v8, true);
+		if (ret)
+			return ret;
+	}
+	if (usbphyc_phy->vdd) {
+		ret = regulator_set_enable(usbphyc_phy->vdd, true);
+		if (ret)
+			return ret;
+	}
+
+	usbphyc_phy->powered = true;
+
+	return 0;
+}
+
+static int stm32_usbphyc_phy_power_off(struct phy *phy)
+{
+	struct stm32_usbphyc *usbphyc = dev_get_priv(phy->dev);
+	struct stm32_usbphyc_phy *usbphyc_phy = usbphyc->phys + phy->id;
+	int ret;
+
+	pr_debug("%s phy ID = %lu\n", __func__, phy->id);
+	usbphyc_phy->powered = false;
+
+	if (stm32_usbphyc_is_powered(usbphyc))
+		return 0;
+
+	if (usbphyc_phy->vdda1v1) {
+		ret = regulator_set_enable(usbphyc_phy->vdda1v1, false);
+		if (ret)
+			return ret;
+	}
+
+	if (usbphyc_phy->vdda1v8) {
+		ret = regulator_set_enable(usbphyc_phy->vdda1v8, false);
+		if (ret)
+			return ret;
+	}
+
+	if (usbphyc_phy->vdd) {
+		ret = regulator_set_enable(usbphyc_phy->vdd, false);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int stm32_usbphyc_get_regulator(struct udevice *dev, ofnode node,
+				       char *supply_name,
+				       struct udevice **regulator)
+{
+	struct ofnode_phandle_args regulator_phandle;
+	int ret;
+
+	ret = ofnode_parse_phandle_with_args(node, supply_name,
+					     NULL, 0, 0,
+					     &regulator_phandle);
+	if (ret) {
+		dev_err(dev, "Can't find %s property (%d)\n", supply_name, ret);
+		return ret;
+	}
+
+	ret = uclass_get_device_by_ofnode(UCLASS_REGULATOR,
+					  regulator_phandle.node,
+					  regulator);
+
+	if (ret) {
+		dev_err(dev, "Can't get %s regulator (%d)\n", supply_name, ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int stm32_usbphyc_of_xlate(struct phy *phy,
+				  struct ofnode_phandle_args *args)
+{
+	if (args->args_count > 1) {
+		pr_debug("%s: invalid args_count: %d\n", __func__,
+			 args->args_count);
+		return -EINVAL;
+	}
+
+	if (args->args[0] >= MAX_PHYS)
+		return -ENODEV;
+
+	if (args->args_count)
+		phy->id = args->args[0];
+	else
+		phy->id = 0;
+
+	return 0;
+}
+
+static const struct phy_ops stm32_usbphyc_phy_ops = {
+	.init = stm32_usbphyc_phy_init,
+	.exit = stm32_usbphyc_phy_exit,
+	.power_on = stm32_usbphyc_phy_power_on,
+	.power_off = stm32_usbphyc_phy_power_off,
+	.of_xlate = stm32_usbphyc_of_xlate,
+};
+
+static int stm32_usbphyc_probe(struct udevice *dev)
+{
+	struct stm32_usbphyc *usbphyc = dev_get_priv(dev);
+	struct reset_ctl reset;
+	ofnode node;
+	int i, ret;
+
+	usbphyc->base = dev_read_addr(dev);
+	if (usbphyc->base == FDT_ADDR_T_NONE)
+		return -EINVAL;
+
+	/* Enable clock */
+	ret = clk_get_by_index(dev, 0, &usbphyc->clk);
+	if (ret)
+		return ret;
+
+	ret = clk_enable(&usbphyc->clk);
+	if (ret)
+		return ret;
+
+	/* Reset */
+	ret = reset_get_by_index(dev, 0, &reset);
+	if (!ret) {
+		reset_assert(&reset);
+		udelay(2);
+		reset_deassert(&reset);
+	}
+
+	/*
+	 * parse all PHY subnodes in order to populate regulator associated
+	 * to each PHY port
+	 */
+	node = dev_read_first_subnode(dev);
+	for (i = 0; i < MAX_PHYS; i++) {
+		struct stm32_usbphyc_phy *usbphyc_phy = usbphyc->phys + i;
+
+		usbphyc_phy->index = i;
+		usbphyc_phy->init = false;
+		usbphyc_phy->powered = false;
+		ret = stm32_usbphyc_get_regulator(dev, node, "phy-supply",
+						  &usbphyc_phy->vdd);
+		if (ret)
+			return ret;
+
+		ret = stm32_usbphyc_get_regulator(dev, node, "vdda1v1-supply",
+						  &usbphyc_phy->vdda1v1);
+		if (ret)
+			return ret;
+
+		ret = stm32_usbphyc_get_regulator(dev, node, "vdda1v8-supply",
+						  &usbphyc_phy->vdda1v8);
+		if (ret)
+			return ret;
+
+		node = dev_read_next_subnode(node);
+	}
+
+	/* Check if second port has to be used for host controller */
+	if (dev_read_bool(dev, "st,port2-switch-to-host"))
+		setbits_le32(usbphyc->base + STM32_USBPHYC_MISC, SWITHOST);
+
+	return 0;
+}
+
+static const struct udevice_id stm32_usbphyc_of_match[] = {
+	{ .compatible = "st,stm32mp1-usbphyc", },
+	{ },
+};
+
+U_BOOT_DRIVER(stm32_usb_phyc) = {
+	.name = "stm32-usbphyc",
+	.id = UCLASS_PHY,
+	.of_match = stm32_usbphyc_of_match,
+	.ops = &stm32_usbphyc_phy_ops,
+	.probe = stm32_usbphyc_probe,
+	.priv_auto_alloc_size = sizeof(struct stm32_usbphyc),
+};