arch/arm/mach-pxa/pxa3xx-ulpi.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * linux/arch/arm/mach-pxa/pxa3xx-ulpi.c
 *
 * code specific to pxa3xx aka Monahans
 *
 * Copyright (C) 2010 CompuLab Ltd.
 *
 * 2010-13-07: Igor Grinberg <grinberg@compulab.co.il>
 *             initial version: pxa310 USB Host mode support
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/usb.h>
#include <linux/usb/otg.h>
#include <linux/soc/pxa/cpu.h>

#include "regs-u2d.h"
#include <linux/platform_data/usb-pxa3xx-ulpi.h>

struct pxa3xx_u2d_ulpi {
	struct clk		*clk;
	void __iomem		*mmio_base;

	struct usb_phy		*otg;
	unsigned int		ulpi_mode;
};

static struct pxa3xx_u2d_ulpi *u2d;

static inline u32 u2d_readl(u32 reg)
{
	return __raw_readl(u2d->mmio_base + reg);
}

static inline void u2d_writel(u32 reg, u32 val)
{
	__raw_writel(val, u2d->mmio_base + reg);
}

#if defined(CONFIG_PXA310_ULPI)
enum u2d_ulpi_phy_mode {
	SYNCH		= 0,
	CARKIT		= (1 << 0),
	SER_3PIN	= (1 << 1),
	SER_6PIN	= (1 << 2),
	LOWPOWER	= (1 << 3),
};

static inline enum u2d_ulpi_phy_mode pxa310_ulpi_get_phymode(void)
{
	return (u2d_readl(U2DOTGUSR) >> 28) & 0xF;
}

static int pxa310_ulpi_poll(void)
{
	int timeout = 50000;

	while (timeout--) {
		if (!(u2d_readl(U2DOTGUCR) & U2DOTGUCR_RUN))
			return 0;

		cpu_relax();
	}

	pr_warn("%s: ULPI access timed out!\n", __func__);

	return -ETIMEDOUT;
}

static int pxa310_ulpi_read(struct usb_phy *otg, u32 reg)
{
	int err;

	if (pxa310_ulpi_get_phymode() != SYNCH) {
		pr_warn("%s: PHY is not in SYNCH mode!\n", __func__);
		return -EBUSY;
	}

	u2d_writel(U2DOTGUCR, U2DOTGUCR_RUN | U2DOTGUCR_RNW | (reg << 16));
	msleep(5);

	err = pxa310_ulpi_poll();
	if (err)
		return err;

	return u2d_readl(U2DOTGUCR) & U2DOTGUCR_RDATA;
}

static int pxa310_ulpi_write(struct usb_phy *otg, u32 val, u32 reg)
{
	if (pxa310_ulpi_get_phymode() != SYNCH) {
		pr_warn("%s: PHY is not in SYNCH mode!\n", __func__);
		return -EBUSY;
	}

	u2d_writel(U2DOTGUCR, U2DOTGUCR_RUN | (reg << 16) | (val << 8));
	msleep(5);

	return pxa310_ulpi_poll();
}

struct usb_phy_io_ops pxa310_ulpi_access_ops = {
	.read	= pxa310_ulpi_read,
	.write	= pxa310_ulpi_write,
};

static void pxa310_otg_transceiver_rtsm(void)
{
	u32 u2dotgcr;

	/* put PHY to sync mode */
	u2dotgcr = u2d_readl(U2DOTGCR);
	u2dotgcr |=  U2DOTGCR_RTSM | U2DOTGCR_UTMID;
	u2d_writel(U2DOTGCR, u2dotgcr);
	msleep(10);

	/* setup OTG sync mode */
	u2dotgcr = u2d_readl(U2DOTGCR);
	u2dotgcr |= U2DOTGCR_ULAF;
	u2dotgcr &= ~(U2DOTGCR_SMAF | U2DOTGCR_CKAF);
	u2d_writel(U2DOTGCR, u2dotgcr);
}

static int pxa310_start_otg_host_transcvr(struct usb_bus *host)
{
	int err;

	pxa310_otg_transceiver_rtsm();

	err = usb_phy_init(u2d->otg);
	if (err) {
		pr_err("OTG transceiver init failed");
		return err;
	}

	err = otg_set_vbus(u2d->otg->otg, 1);
	if (err) {
		pr_err("OTG transceiver VBUS set failed");
		return err;
	}

	err = otg_set_host(u2d->otg->otg, host);
	if (err)
		pr_err("OTG transceiver Host mode set failed");

	return err;
}

static int pxa310_start_otg_hc(struct usb_bus *host)
{
	u32 u2dotgcr;
	int err;

	/* disable USB device controller */
	u2d_writel(U2DCR, u2d_readl(U2DCR) & ~U2DCR_UDE);
	u2d_writel(U2DOTGCR, u2d_readl(U2DOTGCR) | U2DOTGCR_UTMID);
	u2d_writel(U2DOTGICR, u2d_readl(U2DOTGICR) & ~0x37F7F);

	err = pxa310_start_otg_host_transcvr(host);
	if (err)
		return err;

	/* set xceiver mode */
	if (u2d->ulpi_mode & ULPI_IC_6PIN_SERIAL)
		u2d_writel(U2DP3CR, u2d_readl(U2DP3CR) & ~U2DP3CR_P2SS);
	else if (u2d->ulpi_mode & ULPI_IC_3PIN_SERIAL)
		u2d_writel(U2DP3CR, u2d_readl(U2DP3CR) | U2DP3CR_P2SS);

	/* start OTG host controller */
	u2dotgcr = u2d_readl(U2DOTGCR) | U2DOTGCR_SMAF;
	u2d_writel(U2DOTGCR, u2dotgcr & ~(U2DOTGCR_ULAF | U2DOTGCR_CKAF));

	return 0;
}

static void pxa310_stop_otg_hc(void)
{
	pxa310_otg_transceiver_rtsm();

	otg_set_host(u2d->otg->otg, NULL);
	otg_set_vbus(u2d->otg->otg, 0);
	usb_phy_shutdown(u2d->otg);
}

static void pxa310_u2d_setup_otg_hc(void)
{
	u32 u2dotgcr;

	u2dotgcr = u2d_readl(U2DOTGCR);
	u2dotgcr |= U2DOTGCR_ULAF | U2DOTGCR_UTMID;
	u2dotgcr &= ~(U2DOTGCR_SMAF | U2DOTGCR_CKAF);
	u2d_writel(U2DOTGCR, u2dotgcr);
	msleep(5);
	u2d_writel(U2DOTGCR, u2dotgcr | U2DOTGCR_ULE);
	msleep(5);
	u2d_writel(U2DOTGICR, u2d_readl(U2DOTGICR) & ~0x37F7F);
}

static int pxa310_otg_init(struct pxa3xx_u2d_platform_data *pdata)
{
	unsigned int ulpi_mode = ULPI_OTG_DRVVBUS;

	if (pdata) {
		if (pdata->ulpi_mode & ULPI_SER_6PIN)
			ulpi_mode |= ULPI_IC_6PIN_SERIAL;
		else if (pdata->ulpi_mode & ULPI_SER_3PIN)
			ulpi_mode |= ULPI_IC_3PIN_SERIAL;
	}

	u2d->ulpi_mode = ulpi_mode;

	u2d->otg = otg_ulpi_create(&pxa310_ulpi_access_ops, ulpi_mode);
	if (!u2d->otg)
		return -ENOMEM;

	u2d->otg->io_priv = u2d->mmio_base;

	return 0;
}

static void pxa310_otg_exit(void)
{
	kfree(u2d->otg);
}
#else
static inline void pxa310_u2d_setup_otg_hc(void) {}
static inline int pxa310_start_otg_hc(struct usb_bus *host)
{
	return 0;
}
static inline void pxa310_stop_otg_hc(void) {}
static inline int pxa310_otg_init(struct pxa3xx_u2d_platform_data *pdata)
{
	return 0;
}
static inline void pxa310_otg_exit(void) {}
#endif /* CONFIG_PXA310_ULPI */

int pxa3xx_u2d_start_hc(struct usb_bus *host)
{
	int err = 0;

	/* In case the PXA3xx ULPI isn't used, do nothing. */
	if (!u2d)
		return 0;

	clk_prepare_enable(u2d->clk);

	if (cpu_is_pxa310()) {
		pxa310_u2d_setup_otg_hc();
		err = pxa310_start_otg_hc(host);
	}

	return err;
}
EXPORT_SYMBOL_GPL(pxa3xx_u2d_start_hc);

void pxa3xx_u2d_stop_hc(struct usb_bus *host)
{
	/* In case the PXA3xx ULPI isn't used, do nothing. */
	if (!u2d)
		return;

	if (cpu_is_pxa310())
		pxa310_stop_otg_hc();

	clk_disable_unprepare(u2d->clk);
}
EXPORT_SYMBOL_GPL(pxa3xx_u2d_stop_hc);

static int pxa3xx_u2d_probe(struct platform_device *pdev)
{
	struct pxa3xx_u2d_platform_data *pdata = pdev->dev.platform_data;
	struct resource *r;
	int err;

	u2d = kzalloc(sizeof(*u2d), GFP_KERNEL);
	if (!u2d)
		return -ENOMEM;

	u2d->clk = clk_get(&pdev->dev, NULL);
	if (IS_ERR(u2d->clk)) {
		dev_err(&pdev->dev, "failed to get u2d clock\n");
		err = PTR_ERR(u2d->clk);
		goto err_free_mem;
	}

	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!r) {
		dev_err(&pdev->dev, "no IO memory resource defined\n");
		err = -ENODEV;
		goto err_put_clk;
	}

        r = request_mem_region(r->start, resource_size(r), pdev->name);
        if (!r) {
                dev_err(&pdev->dev, "failed to request memory resource\n");
                err = -EBUSY;
                goto err_put_clk;
        }

	u2d->mmio_base = ioremap(r->start, resource_size(r));
	if (!u2d->mmio_base) {
		dev_err(&pdev->dev, "ioremap() failed\n");
		err = -ENODEV;
		goto err_free_res;
	}

	if (pdata->init) {
		err = pdata->init(&pdev->dev);
		if (err)
			goto err_free_io;
	}

	/* Only PXA310 U2D has OTG functionality */
	if (cpu_is_pxa310()) {
		err = pxa310_otg_init(pdata);
		if (err)
			goto err_free_plat;
	}

	platform_set_drvdata(pdev, u2d);

	return 0;

err_free_plat:
	if (pdata->exit)
		pdata->exit(&pdev->dev);
err_free_io:
	iounmap(u2d->mmio_base);
err_free_res:
	release_mem_region(r->start, resource_size(r));
err_put_clk:
	clk_put(u2d->clk);
err_free_mem:
	kfree(u2d);
	return err;
}

static int pxa3xx_u2d_remove(struct platform_device *pdev)
{
	struct pxa3xx_u2d_platform_data *pdata = pdev->dev.platform_data;
	struct resource *r;

	if (cpu_is_pxa310()) {
		pxa310_stop_otg_hc();
		pxa310_otg_exit();
	}

	if (pdata->exit)
		pdata->exit(&pdev->dev);

	platform_set_drvdata(pdev, NULL);
	iounmap(u2d->mmio_base);
	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	release_mem_region(r->start, resource_size(r));

	clk_put(u2d->clk);

	kfree(u2d);

	return 0;
}

static struct platform_driver pxa3xx_u2d_ulpi_driver = {
        .driver		= {
                .name   = "pxa3xx-u2d",
        },
        .probe          = pxa3xx_u2d_probe,
        .remove         = pxa3xx_u2d_remove,
};
module_platform_driver(pxa3xx_u2d_ulpi_driver);

MODULE_DESCRIPTION("PXA3xx U2D ULPI driver");
MODULE_AUTHOR("Igor Grinberg");
MODULE_LICENSE("GPL v2");