phy: add driver for TI TUSB1210 ULPI PHY

TUSB1210 ULPI PHY has vendor specific register for eye
diagram tuning. On some platforms the system firmware has
set optimized value to it. In order to not loose the
optimized value, the driver stores it during probe and
restores it every time the PHY is powered back on.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: David Cohen <david.a.cohen@linux.intel.com>
Acked-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/phy/Kconfig

@@ -309,4 +309,11 @@ config PHY_QCOM_UFS
 	help
 	  Support for UFS PHY on QCOM chipsets.
 
+config PHY_TUSB1210
+	tristate "TI TUSB1210 ULPI PHY module"
+	depends on USB_ULPI_BUS
+	select GENERIC_PHY
+	help
+	  Support for TI TUSB1210 USB ULPI PHY.
+
 endmenu

drivers/phy/Makefile

@@ -40,3 +40,4 @@ obj-$(CONFIG_PHY_STIH41X_USB)		+= phy-stih41x-usb.o
 obj-$(CONFIG_PHY_QCOM_UFS) 	+= phy-qcom-ufs.o
 obj-$(CONFIG_PHY_QCOM_UFS) 	+= phy-qcom-ufs-qmp-20nm.o
 obj-$(CONFIG_PHY_QCOM_UFS) 	+= phy-qcom-ufs-qmp-14nm.o
+obj-$(CONFIG_PHY_TUSB1210)		+= phy-tusb1210.o

drivers/phy/phy-tusb1210.c

@@ -0,0 +1,153 @@
+/**
+ * tusb1210.c - TUSB1210 USB ULPI PHY driver
+ *
+ * Copyright (C) 2015 Intel Corporation
+ *
+ * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/module.h>
+#include <linux/ulpi/driver.h>
+#include <linux/gpio/consumer.h>
+
+#include "ulpi_phy.h"
+
+#define TUSB1210_VENDOR_SPECIFIC2		0x80
+#define TUSB1210_VENDOR_SPECIFIC2_IHSTX_SHIFT	0
+#define TUSB1210_VENDOR_SPECIFIC2_ZHSDRV_SHIFT	4
+#define TUSB1210_VENDOR_SPECIFIC2_DP_SHIFT	6
+
+struct tusb1210 {
+	struct ulpi *ulpi;
+	struct phy *phy;
+	struct gpio_desc *gpio_reset;
+	struct gpio_desc *gpio_cs;
+	u8 vendor_specific2;
+};
+
+static int tusb1210_power_on(struct phy *phy)
+{
+	struct tusb1210 *tusb = phy_get_drvdata(phy);
+
+	gpiod_set_value_cansleep(tusb->gpio_reset, 1);
+	gpiod_set_value_cansleep(tusb->gpio_cs, 1);
+
+	/* Restore the optional eye diagram optimization value */
+	if (tusb->vendor_specific2)
+		ulpi_write(tusb->ulpi, TUSB1210_VENDOR_SPECIFIC2,
+			   tusb->vendor_specific2);
+
+	return 0;
+}
+
+static int tusb1210_power_off(struct phy *phy)
+{
+	struct tusb1210 *tusb = phy_get_drvdata(phy);
+
+	gpiod_set_value_cansleep(tusb->gpio_reset, 0);
+	gpiod_set_value_cansleep(tusb->gpio_cs, 0);
+
+	return 0;
+}
+
+static struct phy_ops phy_ops = {
+	.power_on = tusb1210_power_on,
+	.power_off = tusb1210_power_off,
+	.owner = THIS_MODULE,
+};
+
+static int tusb1210_probe(struct ulpi *ulpi)
+{
+	struct gpio_desc *gpio;
+	struct tusb1210 *tusb;
+	u8 val, reg;
+	int ret;
+
+	tusb = devm_kzalloc(&ulpi->dev, sizeof(*tusb), GFP_KERNEL);
+	if (!tusb)
+		return -ENOMEM;
+
+	gpio = devm_gpiod_get(&ulpi->dev, "reset");
+	if (!IS_ERR(gpio)) {
+		ret = gpiod_direction_output(gpio, 0);
+		if (ret)
+			return ret;
+		gpiod_set_value_cansleep(gpio, 1);
+		tusb->gpio_reset = gpio;
+	}
+
+	gpio = devm_gpiod_get(&ulpi->dev, "cs");
+	if (!IS_ERR(gpio)) {
+		ret = gpiod_direction_output(gpio, 0);
+		if (ret)
+			return ret;
+		gpiod_set_value_cansleep(gpio, 1);
+		tusb->gpio_cs = gpio;
+	}
+
+	/*
+	 * VENDOR_SPECIFIC2 register in TUSB1210 can be used for configuring eye
+	 * diagram optimization and DP/DM swap.
+	 */
+
+	/* High speed output drive strength configuration */
+	device_property_read_u8(&ulpi->dev, "ihstx", &val);
+	reg = val << TUSB1210_VENDOR_SPECIFIC2_IHSTX_SHIFT;
+
+	/* High speed output impedance configuration */
+	device_property_read_u8(&ulpi->dev, "zhsdrv", &val);
+	reg |= val << TUSB1210_VENDOR_SPECIFIC2_ZHSDRV_SHIFT;
+
+	/* DP/DM swap control */
+	device_property_read_u8(&ulpi->dev, "datapolarity", &val);
+	reg |= val << TUSB1210_VENDOR_SPECIFIC2_DP_SHIFT;
+
+	if (reg) {
+		ulpi_write(ulpi, TUSB1210_VENDOR_SPECIFIC2, reg);
+		tusb->vendor_specific2 = reg;
+	}
+
+	tusb->phy = ulpi_phy_create(ulpi, &phy_ops);
+	if (IS_ERR(tusb->phy))
+		return PTR_ERR(tusb->phy);
+
+	tusb->ulpi = ulpi;
+
+	phy_set_drvdata(tusb->phy, tusb);
+	ulpi_set_drvdata(ulpi, tusb);
+	return 0;
+}
+
+static void tusb1210_remove(struct ulpi *ulpi)
+{
+	struct tusb1210 *tusb = ulpi_get_drvdata(ulpi);
+
+	ulpi_phy_destroy(ulpi, tusb->phy);
+}
+
+#define TI_VENDOR_ID 0x0451
+
+static const struct ulpi_device_id tusb1210_ulpi_id[] = {
+	{ TI_VENDOR_ID, 0x1507, },
+	{ },
+};
+MODULE_DEVICE_TABLE(ulpi, tusb1210_ulpi_id);
+
+static struct ulpi_driver tusb1210_driver = {
+	.id_table = tusb1210_ulpi_id,
+	.probe = tusb1210_probe,
+	.remove = tusb1210_remove,
+	.driver = {
+		.name = "tusb1210",
+		.owner = THIS_MODULE,
+	},
+};
+
+module_ulpi_driver(tusb1210_driver);
+
+MODULE_AUTHOR("Intel Corporation");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("TUSB1210 ULPI PHY driver");