drivers/usb/phy/samsung-usbphy.c

/* linux/drivers/usb/phy/samsung-usbphy.c
 *
 * Copyright (c) 2012 Samsung Electronics Co., Ltd.
 *              http://www.samsung.com
 *
 * Author: Praveen Paneri <p.paneri@samsung.com>
 *
 * Samsung USB2.0 High-speed OTG transceiver, talks to S3C HS OTG controller
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/usb/otg.h>
#include <linux/platform_data/samsung-usbphy.h>

/* Register definitions */

#define SAMSUNG_PHYPWR				(0x00)

#define PHYPWR_NORMAL_MASK			(0x19 << 0)
#define PHYPWR_OTG_DISABLE			(0x1 << 4)
#define PHYPWR_ANALOG_POWERDOWN			(0x1 << 3)
#define PHYPWR_FORCE_SUSPEND			(0x1 << 1)
/* For Exynos4 */
#define PHYPWR_NORMAL_MASK_PHY0			(0x39 << 0)
#define PHYPWR_SLEEP_PHY0			(0x1 << 5)

#define SAMSUNG_PHYCLK				(0x04)

#define PHYCLK_MODE_USB11			(0x1 << 6)
#define PHYCLK_EXT_OSC				(0x1 << 5)
#define PHYCLK_COMMON_ON_N			(0x1 << 4)
#define PHYCLK_ID_PULL				(0x1 << 2)
#define PHYCLK_CLKSEL_MASK			(0x3 << 0)
#define PHYCLK_CLKSEL_48M			(0x0 << 0)
#define PHYCLK_CLKSEL_12M			(0x2 << 0)
#define PHYCLK_CLKSEL_24M			(0x3 << 0)

#define SAMSUNG_RSTCON				(0x08)

#define RSTCON_PHYLINK_SWRST			(0x1 << 2)
#define RSTCON_HLINK_SWRST			(0x1 << 1)
#define RSTCON_SWRST				(0x1 << 0)

#ifndef MHZ
#define MHZ (1000*1000)
#endif

#define S3C64XX_USBPHY_ENABLE			(0x1 << 16)
#define EXYNOS_USBPHY_ENABLE			(0x1 << 0)

enum samsung_cpu_type {
	TYPE_S3C64XX,
	TYPE_EXYNOS4210,
};

/*
 * struct samsung_usbphy_drvdata - driver data for various SoC variants
 * @cpu_type: machine identifier
 * @devphy_en_mask: device phy enable mask for PHY CONTROL register
 * @devphy_reg_offset: offset to DEVICE PHY CONTROL register from
 *		       mapped address of system controller.
 *
 *	Here we have a separate mask for device type phy.
 *	Having different masks for host and device type phy helps
 *	in setting independent masks in case of SoCs like S5PV210,
 *	in which PHY0 and PHY1 enable bits belong to same register
 *	placed at position 0 and 1 respectively.
 *	Although for newer SoCs like exynos these bits belong to
 *	different registers altogether placed at position 0.
 */
struct samsung_usbphy_drvdata {
	int cpu_type;
	int devphy_en_mask;
	u32 devphy_reg_offset;
};

/*
 * struct samsung_usbphy - transceiver driver state
 * @phy: transceiver structure
 * @plat: platform data
 * @dev: The parent device supplied to the probe function
 * @clk: usb phy clock
 * @regs: usb phy controller registers memory base
 * @pmuregs: USB device PHY_CONTROL register memory base
 * @ref_clk_freq: reference clock frequency selection
 * @drv_data: driver data available for different SoCs
 * @lock: lock for phy operations
 */
struct samsung_usbphy {
	struct usb_phy	phy;
	struct samsung_usbphy_data *plat;
	struct device	*dev;
	struct clk	*clk;
	void __iomem	*regs;
	void __iomem	*pmuregs;
	int		ref_clk_freq;
	const struct samsung_usbphy_drvdata *drv_data;
	spinlock_t	lock;
};

#define phy_to_sphy(x)		container_of((x), struct samsung_usbphy, phy)

static int samsung_usbphy_parse_dt(struct samsung_usbphy *sphy)
{
	struct device_node *usbphy_sys;

	/* Getting node for system controller interface for usb-phy */
	usbphy_sys = of_get_child_by_name(sphy->dev->of_node, "usbphy-sys");
	if (!usbphy_sys) {
		dev_err(sphy->dev, "No sys-controller interface for usb-phy\n");
		return -ENODEV;
	}

	sphy->pmuregs = of_iomap(usbphy_sys, 0);

	of_node_put(usbphy_sys);

	if (sphy->pmuregs == NULL) {
		dev_err(sphy->dev, "Can't get usb-phy pmu control register\n");
		return -ENODEV;
	}

	return 0;
}

/*
 * Set isolation here for phy.
 * Here 'on = true' would mean USB PHY block is isolated, hence
 * de-activated and vice-versa.
 */
static void samsung_usbphy_set_isolation(struct samsung_usbphy *sphy, bool on)
{
	void __iomem *reg;
	u32 reg_val;
	u32 en_mask;

	if (!sphy->pmuregs) {
		dev_warn(sphy->dev, "Can't set pmu isolation\n");
		return;
	}

	reg = sphy->pmuregs + sphy->drv_data->devphy_reg_offset;
	en_mask = sphy->drv_data->devphy_en_mask;

	reg_val = readl(reg);

	if (on)
		reg_val &= ~en_mask;
	else
		reg_val |= en_mask;

	writel(reg_val, reg);
}

/*
 * Returns reference clock frequency selection value
 */
static int samsung_usbphy_get_refclk_freq(struct samsung_usbphy *sphy)
{
	struct clk *ref_clk;
	int refclk_freq = 0;

	ref_clk = clk_get(sphy->dev, "xusbxti");
	if (IS_ERR(ref_clk)) {
		dev_err(sphy->dev, "Failed to get reference clock\n");
		return PTR_ERR(ref_clk);
	}

	switch (clk_get_rate(ref_clk)) {
	case 12 * MHZ:
		refclk_freq = PHYCLK_CLKSEL_12M;
		break;
	case 24 * MHZ:
		refclk_freq = PHYCLK_CLKSEL_24M;
		break;
	case 48 * MHZ:
		refclk_freq = PHYCLK_CLKSEL_48M;
		break;
	default:
		if (sphy->drv_data->cpu_type == TYPE_S3C64XX)
			refclk_freq = PHYCLK_CLKSEL_48M;
		else
			refclk_freq = PHYCLK_CLKSEL_24M;
		break;
	}
	clk_put(ref_clk);

	return refclk_freq;
}

static void samsung_usbphy_enable(struct samsung_usbphy *sphy)
{
	void __iomem *regs = sphy->regs;
	u32 phypwr;
	u32 phyclk;
	u32 rstcon;

	/* set clock frequency for PLL */
	phyclk = sphy->ref_clk_freq;
	phypwr = readl(regs + SAMSUNG_PHYPWR);
	rstcon = readl(regs + SAMSUNG_RSTCON);

	switch (sphy->drv_data->cpu_type) {
	case TYPE_S3C64XX:
		phyclk &= ~PHYCLK_COMMON_ON_N;
		phypwr &= ~PHYPWR_NORMAL_MASK;
		rstcon |= RSTCON_SWRST;
		break;
	case TYPE_EXYNOS4210:
		phypwr &= ~PHYPWR_NORMAL_MASK_PHY0;
		rstcon |= RSTCON_SWRST;
	default:
		break;
	}

	writel(phyclk, regs + SAMSUNG_PHYCLK);
	/* Configure PHY0 for normal operation*/
	writel(phypwr, regs + SAMSUNG_PHYPWR);
	/* reset all ports of PHY and Link */
	writel(rstcon, regs + SAMSUNG_RSTCON);
	udelay(10);
	rstcon &= ~RSTCON_SWRST;
	writel(rstcon, regs + SAMSUNG_RSTCON);
}

static void samsung_usbphy_disable(struct samsung_usbphy *sphy)
{
	void __iomem *regs = sphy->regs;
	u32 phypwr;

	phypwr = readl(regs + SAMSUNG_PHYPWR);

	switch (sphy->drv_data->cpu_type) {
	case TYPE_S3C64XX:
		phypwr |= PHYPWR_NORMAL_MASK;
		break;
	case TYPE_EXYNOS4210:
		phypwr |= PHYPWR_NORMAL_MASK_PHY0;
	default:
		break;
	}

	/* Disable analog and otg block power */
	writel(phypwr, regs + SAMSUNG_PHYPWR);
}

/*
 * The function passed to the usb driver for phy initialization
 */
static int samsung_usbphy_init(struct usb_phy *phy)
{
	struct samsung_usbphy *sphy;
	unsigned long flags;
	int ret = 0;

	sphy = phy_to_sphy(phy);

	/* Enable the phy clock */
	ret = clk_prepare_enable(sphy->clk);
	if (ret) {
		dev_err(sphy->dev, "%s: clk_prepare_enable failed\n", __func__);
		return ret;
	}

	spin_lock_irqsave(&sphy->lock, flags);

	/* Disable phy isolation */
	if (sphy->plat && sphy->plat->pmu_isolation)
		sphy->plat->pmu_isolation(false);
	else
		samsung_usbphy_set_isolation(sphy, false);

	/* Initialize usb phy registers */
	samsung_usbphy_enable(sphy);

	spin_unlock_irqrestore(&sphy->lock, flags);

	/* Disable the phy clock */
	clk_disable_unprepare(sphy->clk);
	return ret;
}

/*
 * The function passed to the usb driver for phy shutdown
 */
static void samsung_usbphy_shutdown(struct usb_phy *phy)
{
	struct samsung_usbphy *sphy;
	unsigned long flags;

	sphy = phy_to_sphy(phy);

	if (clk_prepare_enable(sphy->clk)) {
		dev_err(sphy->dev, "%s: clk_prepare_enable failed\n", __func__);
		return;
	}

	spin_lock_irqsave(&sphy->lock, flags);

	/* De-initialize usb phy registers */
	samsung_usbphy_disable(sphy);

	/* Enable phy isolation */
	if (sphy->plat && sphy->plat->pmu_isolation)
		sphy->plat->pmu_isolation(true);
	else
		samsung_usbphy_set_isolation(sphy, true);

	spin_unlock_irqrestore(&sphy->lock, flags);

	clk_disable_unprepare(sphy->clk);
}

static const struct of_device_id samsung_usbphy_dt_match[];

static inline const struct samsung_usbphy_drvdata
*samsung_usbphy_get_driver_data(struct platform_device *pdev)
{
	if (pdev->dev.of_node) {
		const struct of_device_id *match;
		match = of_match_node(samsung_usbphy_dt_match,
							pdev->dev.of_node);
		return match->data;
	}

	return (struct samsung_usbphy_drvdata *)
				platform_get_device_id(pdev)->driver_data;
}

static int __devinit samsung_usbphy_probe(struct platform_device *pdev)
{
	struct samsung_usbphy *sphy;
	struct samsung_usbphy_data *pdata = pdev->dev.platform_data;
	struct device *dev = &pdev->dev;
	struct resource *phy_mem;
	void __iomem	*phy_base;
	struct clk *clk;
	int ret;

	phy_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!phy_mem) {
		dev_err(dev, "%s: missing mem resource\n", __func__);
		return -ENODEV;
	}

	phy_base = devm_request_and_ioremap(dev, phy_mem);
	if (!phy_base) {
		dev_err(dev, "%s: register mapping failed\n", __func__);
		return -ENXIO;
	}

	sphy = devm_kzalloc(dev, sizeof(*sphy), GFP_KERNEL);
	if (!sphy)
		return -ENOMEM;

	clk = devm_clk_get(dev, "otg");
	if (IS_ERR(clk)) {
		dev_err(dev, "Failed to get otg clock\n");
		return PTR_ERR(clk);
	}

	sphy->dev = dev;

	if (dev->of_node) {
		ret = samsung_usbphy_parse_dt(sphy);
		if (ret < 0)
			return ret;
	} else {
		if (!pdata) {
			dev_err(dev, "no platform data specified\n");
			return -EINVAL;
		}
	}

	sphy->plat		= pdata;
	sphy->regs		= phy_base;
	sphy->clk		= clk;
	sphy->phy.dev		= sphy->dev;
	sphy->phy.label		= "samsung-usbphy";
	sphy->phy.init		= samsung_usbphy_init;
	sphy->phy.shutdown	= samsung_usbphy_shutdown;
	sphy->drv_data		= samsung_usbphy_get_driver_data(pdev);
	sphy->ref_clk_freq	= samsung_usbphy_get_refclk_freq(sphy);

	spin_lock_init(&sphy->lock);

	platform_set_drvdata(pdev, sphy);

	return usb_add_phy(&sphy->phy, USB_PHY_TYPE_USB2);
}

static int __exit samsung_usbphy_remove(struct platform_device *pdev)
{
	struct samsung_usbphy *sphy = platform_get_drvdata(pdev);

	usb_remove_phy(&sphy->phy);

	if (sphy->pmuregs)
		iounmap(sphy->pmuregs);

	return 0;
}

static const struct samsung_usbphy_drvdata usbphy_s3c64xx = {
	.cpu_type		= TYPE_S3C64XX,
	.devphy_en_mask		= S3C64XX_USBPHY_ENABLE,
};

static const struct samsung_usbphy_drvdata usbphy_exynos4 = {
	.cpu_type		= TYPE_EXYNOS4210,
	.devphy_en_mask		= EXYNOS_USBPHY_ENABLE,
};

#ifdef CONFIG_OF
static const struct of_device_id samsung_usbphy_dt_match[] = {
	{
		.compatible = "samsung,s3c64xx-usbphy",
		.data = &usbphy_s3c64xx,
	}, {
		.compatible = "samsung,exynos4210-usbphy",
		.data = &usbphy_exynos4,
	},
	{},
};
MODULE_DEVICE_TABLE(of, samsung_usbphy_dt_match);
#endif

static struct platform_device_id samsung_usbphy_driver_ids[] = {
	{
		.name		= "s3c64xx-usbphy",
		.driver_data	= (unsigned long)&usbphy_s3c64xx,
	}, {
		.name		= "exynos4210-usbphy",
		.driver_data	= (unsigned long)&usbphy_exynos4,
	},
	{},
};

MODULE_DEVICE_TABLE(platform, samsung_usbphy_driver_ids);

static struct platform_driver samsung_usbphy_driver = {
	.probe		= samsung_usbphy_probe,
	.remove		= __devexit_p(samsung_usbphy_remove),
	.id_table	= samsung_usbphy_driver_ids,
	.driver		= {
		.name	= "samsung-usbphy",
		.owner	= THIS_MODULE,
		.of_match_table = of_match_ptr(samsung_usbphy_dt_match),
	},
};

module_platform_driver(samsung_usbphy_driver);

MODULE_DESCRIPTION("Samsung USB phy controller");
MODULE_AUTHOR("Praveen Paneri <p.paneri@samsung.com>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:samsung-usbphy");