phy: Add a new driver for OMAP's USB2 PHYs

This drivers supports the USB2 PHY found on omap5 and dra7 SOCs.

Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>

drivers/phy/Kconfig

@@ -155,4 +155,13 @@ config MSM8916_USB_PHY
 
 	  This PHY is found on qualcomm dragonboard410c development board.
 
+config OMAP_USB2_PHY
+	bool "Support OMAP's USB2 PHY"
+	depends on PHY
+	depends on SYSCON
+	help
+	  Support for the OMAP's USB2 PHY.
+
+	  This PHY is found on OMAP devices supporting USB2.
+
 endmenu

drivers/phy/Makefile

@@ -17,3 +17,4 @@ obj-$(CONFIG_PHY_RCAR_GEN3) += phy-rcar-gen3.o
 obj-$(CONFIG_PHY_STM32_USBPHYC) += phy-stm32-usbphyc.o
 obj-$(CONFIG_MESON_GXL_USB_PHY) += meson-gxl-usb2.o meson-gxl-usb3.o
 obj-$(CONFIG_MSM8916_USB_PHY) += msm8916-usbh-phy.o
+obj-$(CONFIG_OMAP_USB2_PHY) += omap-usb2-phy.o

drivers/phy/omap-usb2-phy.c

@@ -0,0 +1,196 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * OMAP USB2 PHY LAYER
+ *
+ * Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com
+ * Written by Jean-Jacques Hiblot <jjhiblot@ti.com>
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <dm.h>
+#include <errno.h>
+#include <generic-phy.h>
+#include <regmap.h>
+#include <syscon.h>
+
+#define OMAP_USB2_CALIBRATE_FALSE_DISCONNECT	BIT(0)
+
+#define OMAP_DEV_PHY_PD		BIT(0)
+#define OMAP_USB2_PHY_PD	BIT(28)
+
+#define USB2PHY_DISCON_BYP_LATCH	BIT(31)
+#define USB2PHY_ANA_CONFIG1		(0x4c)
+
+DECLARE_GLOBAL_DATA_PTR;
+
+struct omap_usb2_phy {
+	struct regmap *pwr_regmap;
+	ulong flags;
+	void *phy_base;
+	u32 pwr_reg_offset;
+};
+
+struct usb_phy_data {
+	const char *label;
+	u8 flags;
+	u32 mask;
+	u32 power_on;
+	u32 power_off;
+};
+
+static const struct usb_phy_data omap5_usb2_data = {
+	.label = "omap5_usb2",
+	.flags = 0,
+	.mask = OMAP_DEV_PHY_PD,
+	.power_off = OMAP_DEV_PHY_PD,
+};
+
+static const struct usb_phy_data dra7x_usb2_data = {
+	.label = "dra7x_usb2",
+	.flags = OMAP_USB2_CALIBRATE_FALSE_DISCONNECT,
+	.mask = OMAP_DEV_PHY_PD,
+	.power_off = OMAP_DEV_PHY_PD,
+};
+
+static const struct usb_phy_data dra7x_usb2_phy2_data = {
+	.label = "dra7x_usb2_phy2",
+	.flags = OMAP_USB2_CALIBRATE_FALSE_DISCONNECT,
+	.mask = OMAP_USB2_PHY_PD,
+	.power_off = OMAP_USB2_PHY_PD,
+};
+
+static const struct udevice_id omap_usb2_id_table[] = {
+	{
+		.compatible = "ti,omap5-usb2",
+		.data = (ulong)&omap5_usb2_data,
+	},
+	{
+		.compatible = "ti,dra7x-usb2",
+		.data = (ulong)&dra7x_usb2_data,
+	},
+	{
+		.compatible = "ti,dra7x-usb2-phy2",
+		.data = (ulong)&dra7x_usb2_phy2_data,
+	},
+	{},
+};
+
+static int omap_usb_phy_power(struct phy *usb_phy, bool on)
+{
+	struct udevice *dev = usb_phy->dev;
+	const struct usb_phy_data *data;
+	const struct omap_usb2_phy *phy = dev_get_priv(dev);
+	u32 val;
+	int rc;
+
+	data = (const struct usb_phy_data *)dev_get_driver_data(dev);
+	if (!data)
+		return -EINVAL;
+
+	rc = regmap_read(phy->pwr_regmap, phy->pwr_reg_offset, &val);
+	if (rc)
+		return rc;
+	val &= ~data->mask;
+	if (on)
+		val |= data->power_on;
+	else
+		val |= data->power_off;
+	rc = regmap_write(phy->pwr_regmap, phy->pwr_reg_offset, val);
+	if (rc)
+		return rc;
+
+	return 0;
+}
+
+static int omap_usb2_phy_init(struct phy *usb_phy)
+{
+	struct udevice *dev = usb_phy->dev;
+	struct omap_usb2_phy *priv = dev_get_priv(dev);
+	u32 val;
+
+	if (priv->flags & OMAP_USB2_CALIBRATE_FALSE_DISCONNECT) {
+		/*
+		 *
+		 * Reduce the sensitivity of internal PHY by enabling the
+		 * DISCON_BYP_LATCH of the USB2PHY_ANA_CONFIG1 register. This
+		 * resolves issues with certain devices which can otherwise
+		 * be prone to false disconnects.
+		 *
+		 */
+		val = readl(priv->phy_base + USB2PHY_ANA_CONFIG1);
+		val |= USB2PHY_DISCON_BYP_LATCH;
+		writel(val, priv->phy_base + USB2PHY_ANA_CONFIG1);
+	}
+
+	return 0;
+}
+
+static int omap_usb2_phy_power_on(struct phy *usb_phy)
+{
+	return omap_usb_phy_power(usb_phy, true);
+}
+
+static int omap_usb2_phy_power_off(struct phy *usb_phy)
+{
+	return omap_usb_phy_power(usb_phy, false);
+}
+
+static int omap_usb2_phy_exit(struct phy *usb_phy)
+{
+	return omap_usb_phy_power(usb_phy, false);
+}
+
+struct phy_ops omap_usb2_phy_ops = {
+	.init = omap_usb2_phy_init,
+	.power_on = omap_usb2_phy_power_on,
+	.power_off = omap_usb2_phy_power_off,
+	.exit = omap_usb2_phy_exit,
+};
+
+int omap_usb2_phy_probe(struct udevice *dev)
+{
+	int rc;
+	struct regmap *regmap;
+	struct omap_usb2_phy *priv = dev_get_priv(dev);
+	const struct usb_phy_data *data;
+	u32 tmp[2];
+
+	data = (const struct usb_phy_data *)dev_get_driver_data(dev);
+	if (!data)
+		return -EINVAL;
+
+	if (data->flags & OMAP_USB2_CALIBRATE_FALSE_DISCONNECT) {
+		u32 base = dev_read_addr(dev);
+
+		if (base == FDT_ADDR_T_NONE)
+			return -EINVAL;
+		priv->phy_base = (void *)base;
+		priv->flags |= OMAP_USB2_CALIBRATE_FALSE_DISCONNECT;
+	}
+
+	regmap = syscon_regmap_lookup_by_phandle(dev, "syscon-phy-power");
+	if (IS_ERR(regmap)) {
+		printf("can't get regmap (err %ld)\n", PTR_ERR(regmap));
+		return PTR_ERR(regmap);
+	}
+	priv->pwr_regmap = regmap;
+
+	rc =  dev_read_u32_array(dev, "syscon-phy-power", tmp, 2);
+	if (rc) {
+		printf("couldn't get power reg. offset (err %d)\n", rc);
+		return rc;
+	}
+	priv->pwr_reg_offset = tmp[1];
+
+	return 0;
+}
+
+U_BOOT_DRIVER(omap_usb2_phy) = {
+	.name = "omap_usb2_phy",
+	.id = UCLASS_PHY,
+	.of_match = omap_usb2_id_table,
+	.probe = omap_usb2_phy_probe,
+	.ops = &omap_usb2_phy_ops,
+	.priv_auto_alloc_size = sizeof(struct omap_usb2_phy),
+};