root/drivers/phy/motorola/phy-cpcap-usb.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Motorola CPCAP PMIC USB PHY driver
 * Copyright (C) 2017 Tony Lindgren <tony@atomide.com>
 *
 * Some parts based on earlier Motorola Linux kernel tree code in
 * board-mapphone-usb.c and cpcap-usb-det.c:
 * Copyright (C) 2007 - 2011 Motorola, Inc.
 */

#include <linux/atomic.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/iio/consumer.h>
#include <linux/pinctrl/consumer.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/slab.h>

#include <linux/gpio/consumer.h>
#include <linux/mfd/motorola-cpcap.h>
#include <linux/phy/omap_usb.h>
#include <linux/phy/phy.h>
#include <linux/regulator/consumer.h>
#include <linux/usb/musb.h>

/* CPCAP_REG_USBC1 register bits */
#define CPCAP_BIT_IDPULSE               BIT(15)
#define CPCAP_BIT_ID100KPU              BIT(14)
#define CPCAP_BIT_IDPUCNTRL             BIT(13)
#define CPCAP_BIT_IDPU                  BIT(12)
#define CPCAP_BIT_IDPD                  BIT(11)
#define CPCAP_BIT_VBUSCHRGTMR3          BIT(10)
#define CPCAP_BIT_VBUSCHRGTMR2          BIT(9)
#define CPCAP_BIT_VBUSCHRGTMR1          BIT(8)
#define CPCAP_BIT_VBUSCHRGTMR0          BIT(7)
#define CPCAP_BIT_VBUSPU                BIT(6)
#define CPCAP_BIT_VBUSPD                BIT(5)
#define CPCAP_BIT_DMPD                  BIT(4)
#define CPCAP_BIT_DPPD                  BIT(3)
#define CPCAP_BIT_DM1K5PU               BIT(2)
#define CPCAP_BIT_DP1K5PU               BIT(1)
#define CPCAP_BIT_DP150KPU              BIT(0)

/* CPCAP_REG_USBC2 register bits */
#define CPCAP_BIT_ZHSDRV1               BIT(15)
#define CPCAP_BIT_ZHSDRV0               BIT(14)
#define CPCAP_BIT_DPLLCLKREQ            BIT(13)
#define CPCAP_BIT_SE0CONN               BIT(12)
#define CPCAP_BIT_UARTTXTRI             BIT(11)
#define CPCAP_BIT_UARTSWAP              BIT(10)
#define CPCAP_BIT_UARTMUX1              BIT(9)
#define CPCAP_BIT_UARTMUX0              BIT(8)
#define CPCAP_BIT_ULPISTPLOW            BIT(7)
#define CPCAP_BIT_TXENPOL               BIT(6)
#define CPCAP_BIT_USBXCVREN             BIT(5)
#define CPCAP_BIT_USBCNTRL              BIT(4)
#define CPCAP_BIT_USBSUSPEND            BIT(3)
#define CPCAP_BIT_EMUMODE2              BIT(2)
#define CPCAP_BIT_EMUMODE1              BIT(1)
#define CPCAP_BIT_EMUMODE0              BIT(0)

/* CPCAP_REG_USBC3 register bits */
#define CPCAP_BIT_SPARE_898_15          BIT(15)
#define CPCAP_BIT_IHSTX03               BIT(14)
#define CPCAP_BIT_IHSTX02               BIT(13)
#define CPCAP_BIT_IHSTX01               BIT(12)
#define CPCAP_BIT_IHSTX0                BIT(11)
#define CPCAP_BIT_IDPU_SPI              BIT(10)
#define CPCAP_BIT_UNUSED_898_9          BIT(9)
#define CPCAP_BIT_VBUSSTBY_EN           BIT(8)
#define CPCAP_BIT_VBUSEN_SPI            BIT(7)
#define CPCAP_BIT_VBUSPU_SPI            BIT(6)
#define CPCAP_BIT_VBUSPD_SPI            BIT(5)
#define CPCAP_BIT_DMPD_SPI              BIT(4)
#define CPCAP_BIT_DPPD_SPI              BIT(3)
#define CPCAP_BIT_SUSPEND_SPI           BIT(2)
#define CPCAP_BIT_PU_SPI                BIT(1)
#define CPCAP_BIT_ULPI_SPI_SEL          BIT(0)

struct cpcap_usb_ints_state {
        bool id_ground;
        bool id_float;
        bool chrg_det;
        bool rvrs_chrg;
        bool vbusov;

        bool chrg_se1b;
        bool se0conn;
        bool rvrs_mode;
        bool chrgcurr1;
        bool vbusvld;
        bool sessvld;
        bool sessend;
        bool se1;

        bool battdetb;
        bool dm;
        bool dp;
};

enum cpcap_gpio_mode {
        CPCAP_DM_DP,
        CPCAP_MDM_RX_TX,
        CPCAP_UNKNOWN_DISABLED, /* Seems to disable USB lines */
        CPCAP_OTG_DM_DP,
};

struct cpcap_phy_ddata {
        struct regmap *reg;
        struct device *dev;
        struct usb_phy phy;
        struct delayed_work detect_work;
        struct pinctrl *pins;
        struct pinctrl_state *pins_ulpi;
        struct pinctrl_state *pins_utmi;
        struct pinctrl_state *pins_uart;
        struct gpio_desc *gpio[2];
        struct iio_channel *vbus;
        struct iio_channel *id;
        struct regulator *vusb;
        atomic_t active;
        unsigned int vbus_provider:1;
        unsigned int docked:1;
};

static bool cpcap_usb_vbus_valid(struct cpcap_phy_ddata *ddata)
{
        int error, value = 0;

        error = iio_read_channel_processed(ddata->vbus, &value);
        if (error >= 0)
                return value > 3900;

        dev_err(ddata->dev, "error reading VBUS: %i\n", error);

        return false;
}

static int cpcap_usb_phy_set_host(struct usb_otg *otg, struct usb_bus *host)
{
        otg->host = host;
        if (!host)
                otg->state = OTG_STATE_UNDEFINED;

        return 0;
}

static int cpcap_usb_phy_set_peripheral(struct usb_otg *otg,
                                        struct usb_gadget *gadget)
{
        otg->gadget = gadget;
        if (!gadget)
                otg->state = OTG_STATE_UNDEFINED;

        return 0;
}

static const struct phy_ops ops = {
        .owner          = THIS_MODULE,
};

static int cpcap_phy_get_ints_state(struct cpcap_phy_ddata *ddata,
                                    struct cpcap_usb_ints_state *s)
{
        int val, error;

        error = regmap_read(ddata->reg, CPCAP_REG_INTS1, &val);
        if (error)
                return error;

        s->id_ground = val & BIT(15);
        s->id_float = val & BIT(14);
        s->vbusov = val & BIT(11);

        error = regmap_read(ddata->reg, CPCAP_REG_INTS2, &val);
        if (error)
                return error;

        s->vbusvld = val & BIT(3);
        s->sessvld = val & BIT(2);
        s->sessend = val & BIT(1);
        s->se1 = val & BIT(0);

        error = regmap_read(ddata->reg, CPCAP_REG_INTS4, &val);
        if (error)
                return error;

        s->dm = val & BIT(1);
        s->dp = val & BIT(0);

        return 0;
}

static int cpcap_usb_set_uart_mode(struct cpcap_phy_ddata *ddata);
static int cpcap_usb_set_usb_mode(struct cpcap_phy_ddata *ddata);

static void cpcap_usb_try_musb_mailbox(struct cpcap_phy_ddata *ddata,
                                       enum musb_vbus_id_status status)
{
        int error;

        error = musb_mailbox(status);
        if (!error)
                return;

        dev_dbg(ddata->dev, "%s: musb_mailbox failed: %i\n",
                __func__, error);
}

static void cpcap_usb_detect(struct work_struct *work)
{
        struct cpcap_phy_ddata *ddata;
        struct cpcap_usb_ints_state s;
        bool vbus = false;
        int error;

        ddata = container_of(work, struct cpcap_phy_ddata, detect_work.work);

        error = cpcap_phy_get_ints_state(ddata, &s);
        if (error)
                return;

        vbus = cpcap_usb_vbus_valid(ddata);

        /* We need to kick the VBUS as USB A-host */
        if (s.id_ground && ddata->vbus_provider) {
                dev_dbg(ddata->dev, "still in USB A-host mode, kicking VBUS\n");

                cpcap_usb_try_musb_mailbox(ddata, MUSB_ID_GROUND);

                error = regmap_update_bits(ddata->reg, CPCAP_REG_USBC3,
                                           CPCAP_BIT_VBUSSTBY_EN |
                                           CPCAP_BIT_VBUSEN_SPI,
                                           CPCAP_BIT_VBUSEN_SPI);
                if (error)
                        goto out_err;

                return;
        }

        if (vbus && s.id_ground && ddata->docked) {
                dev_dbg(ddata->dev, "still docked as A-host, signal ID down\n");

                cpcap_usb_try_musb_mailbox(ddata, MUSB_ID_GROUND);

                return;
        }

        /* No VBUS needed with docks */
        if (vbus && s.id_ground && !ddata->vbus_provider) {
                dev_dbg(ddata->dev, "connected to a dock\n");

                ddata->docked = true;

                error = cpcap_usb_set_usb_mode(ddata);
                if (error)
                        goto out_err;

                cpcap_usb_try_musb_mailbox(ddata, MUSB_ID_GROUND);

                /*
                 * Force check state again after musb has reoriented,
                 * otherwise devices won't enumerate after loading PHY
                 * driver.
                 */
                schedule_delayed_work(&ddata->detect_work,
                                      msecs_to_jiffies(1000));

                return;
        }

        if (s.id_ground && !ddata->docked) {
                dev_dbg(ddata->dev, "id ground, USB host mode\n");

                ddata->vbus_provider = true;

                error = cpcap_usb_set_usb_mode(ddata);
                if (error)
                        goto out_err;

                cpcap_usb_try_musb_mailbox(ddata, MUSB_ID_GROUND);

                error = regmap_update_bits(ddata->reg, CPCAP_REG_USBC3,
                                           CPCAP_BIT_VBUSSTBY_EN |
                                           CPCAP_BIT_VBUSEN_SPI,
                                           CPCAP_BIT_VBUSEN_SPI);
                if (error)
                        goto out_err;

                return;
        }

        error = regmap_update_bits(ddata->reg, CPCAP_REG_USBC3,
                                   CPCAP_BIT_VBUSSTBY_EN |
                                   CPCAP_BIT_VBUSEN_SPI, 0);
        if (error)
                goto out_err;

        vbus = cpcap_usb_vbus_valid(ddata);

        /* Otherwise assume we're connected to a USB host */
        if (vbus) {
                dev_dbg(ddata->dev, "connected to USB host\n");
                error = cpcap_usb_set_usb_mode(ddata);
                if (error)
                        goto out_err;
                cpcap_usb_try_musb_mailbox(ddata, MUSB_VBUS_VALID);

                return;
        }

        ddata->vbus_provider = false;
        ddata->docked = false;
        cpcap_usb_try_musb_mailbox(ddata, MUSB_VBUS_OFF);

        /* Default to debug UART mode */
        error = cpcap_usb_set_uart_mode(ddata);
        if (error)
                goto out_err;

        dev_dbg(ddata->dev, "set UART mode\n");

        return;

out_err:
        dev_err(ddata->dev, "error setting cable state: %i\n", error);
}

static irqreturn_t cpcap_phy_irq_thread(int irq, void *data)
{
        struct cpcap_phy_ddata *ddata = data;

        if (!atomic_read(&ddata->active))
                return IRQ_NONE;

        schedule_delayed_work(&ddata->detect_work, msecs_to_jiffies(1));

        return IRQ_HANDLED;
}

static int cpcap_usb_init_irq(struct platform_device *pdev,
                              struct cpcap_phy_ddata *ddata,
                              const char *name)
{
        int irq, error;

        irq = platform_get_irq_byname(pdev, name);
        if (irq < 0)
                return -ENODEV;

        error = devm_request_threaded_irq(ddata->dev, irq, NULL,
                                          cpcap_phy_irq_thread,
                                          IRQF_SHARED |
                                          IRQF_ONESHOT,
                                          name, ddata);
        if (error) {
                dev_err(ddata->dev, "could not get irq %s: %i\n",
                        name, error);

                return error;
        }

        return 0;
}

static const char * const cpcap_phy_irqs[] = {
        /* REG_INT_0 */
        "id_ground", "id_float",

        /* REG_INT1 */
        "se0conn", "vbusvld", "sessvld", "sessend", "se1",

        /* REG_INT_3 */
        "dm", "dp",
};

static int cpcap_usb_init_interrupts(struct platform_device *pdev,
                                     struct cpcap_phy_ddata *ddata)
{
        int i, error;

        for (i = 0; i < ARRAY_SIZE(cpcap_phy_irqs); i++) {
                error = cpcap_usb_init_irq(pdev, ddata, cpcap_phy_irqs[i]);
                if (error)
                        return error;
        }

        return 0;
}

/*
 * Optional pins and modes. At least Motorola mapphone devices
 * are using two GPIOs and dynamic pinctrl to multiplex PHY pins
 * to UART, ULPI or UTMI mode.
 */

static int cpcap_usb_gpio_set_mode(struct cpcap_phy_ddata *ddata,
                                   enum cpcap_gpio_mode mode)
{
        if (!ddata->gpio[0] || !ddata->gpio[1])
                return 0;

        gpiod_set_value(ddata->gpio[0], mode & 1);
        gpiod_set_value(ddata->gpio[1], mode >> 1);

        return 0;
}

static int cpcap_usb_set_uart_mode(struct cpcap_phy_ddata *ddata)
{
        int error;

        /* Disable lines to prevent glitches from waking up mdm6600 */
        error = cpcap_usb_gpio_set_mode(ddata, CPCAP_UNKNOWN_DISABLED);
        if (error)
                goto out_err;

        if (ddata->pins_uart) {
                error = pinctrl_select_state(ddata->pins, ddata->pins_uart);
                if (error)
                        goto out_err;
        }

        error = regmap_update_bits(ddata->reg, CPCAP_REG_USBC1,
                                   CPCAP_BIT_VBUSPD,
                                   CPCAP_BIT_VBUSPD);
        if (error)
                goto out_err;

        error = regmap_update_bits(ddata->reg, CPCAP_REG_USBC2,
                                   0xffff, CPCAP_BIT_UARTMUX0 |
                                   CPCAP_BIT_EMUMODE0);
        if (error)
                goto out_err;

        error = regmap_update_bits(ddata->reg, CPCAP_REG_USBC3, 0x7fff,
                                   CPCAP_BIT_IDPU_SPI);
        if (error)
                goto out_err;

        /* Enable UART mode */
        error = cpcap_usb_gpio_set_mode(ddata, CPCAP_DM_DP);
        if (error)
                goto out_err;

        return 0;

out_err:
        dev_err(ddata->dev, "%s failed with %i\n", __func__, error);

        return error;
}

static int cpcap_usb_set_usb_mode(struct cpcap_phy_ddata *ddata)
{
        int error;

        /* Disable lines to prevent glitches from waking up mdm6600 */
        error = cpcap_usb_gpio_set_mode(ddata, CPCAP_UNKNOWN_DISABLED);
        if (error)
                return error;

        if (ddata->pins_utmi) {
                error = pinctrl_select_state(ddata->pins, ddata->pins_utmi);
                if (error) {
                        dev_err(ddata->dev, "could not set usb mode: %i\n",
                                error);

                        return error;
                }
        }

        error = regmap_update_bits(ddata->reg, CPCAP_REG_USBC1,
                                   CPCAP_BIT_VBUSPD, 0);
        if (error)
                goto out_err;

        error = regmap_update_bits(ddata->reg, CPCAP_REG_USBC3,
                                   CPCAP_BIT_PU_SPI |
                                   CPCAP_BIT_DMPD_SPI |
                                   CPCAP_BIT_DPPD_SPI |
                                   CPCAP_BIT_SUSPEND_SPI |
                                   CPCAP_BIT_ULPI_SPI_SEL, 0);
        if (error)
                goto out_err;

        error = regmap_update_bits(ddata->reg, CPCAP_REG_USBC2,
                                   CPCAP_BIT_USBXCVREN,
                                   CPCAP_BIT_USBXCVREN);
        if (error)
                goto out_err;

        /* Enable USB mode */
        error = cpcap_usb_gpio_set_mode(ddata, CPCAP_OTG_DM_DP);
        if (error)
                goto out_err;

        return 0;

out_err:
        dev_err(ddata->dev, "%s failed with %i\n", __func__, error);

        return error;
}

static int cpcap_usb_init_optional_pins(struct cpcap_phy_ddata *ddata)
{
        ddata->pins = devm_pinctrl_get(ddata->dev);
        if (IS_ERR(ddata->pins)) {
                dev_info(ddata->dev, "default pins not configured: %ld\n",
                         PTR_ERR(ddata->pins));
                ddata->pins = NULL;

                return 0;
        }

        ddata->pins_ulpi = pinctrl_lookup_state(ddata->pins, "ulpi");
        if (IS_ERR(ddata->pins_ulpi)) {
                dev_info(ddata->dev, "ulpi pins not configured\n");
                ddata->pins_ulpi = NULL;
        }

        ddata->pins_utmi = pinctrl_lookup_state(ddata->pins, "utmi");
        if (IS_ERR(ddata->pins_utmi)) {
                dev_info(ddata->dev, "utmi pins not configured\n");
                ddata->pins_utmi = NULL;
        }

        ddata->pins_uart = pinctrl_lookup_state(ddata->pins, "uart");
        if (IS_ERR(ddata->pins_uart)) {
                dev_info(ddata->dev, "uart pins not configured\n");
                ddata->pins_uart = NULL;
        }

        if (ddata->pins_uart)
                return pinctrl_select_state(ddata->pins, ddata->pins_uart);

        return 0;
}

static void cpcap_usb_init_optional_gpios(struct cpcap_phy_ddata *ddata)
{
        int i;

        for (i = 0; i < 2; i++) {
                ddata->gpio[i] = devm_gpiod_get_index(ddata->dev, "mode",
                                                      i, GPIOD_OUT_HIGH);
                if (IS_ERR(ddata->gpio[i])) {
                        dev_info(ddata->dev, "no mode change GPIO%i: %li\n",
                                 i, PTR_ERR(ddata->gpio[i]));
                        ddata->gpio[i] = NULL;
                }
        }
}

static int cpcap_usb_init_iio(struct cpcap_phy_ddata *ddata)
{
        enum iio_chan_type type;
        int error;

        ddata->vbus = devm_iio_channel_get(ddata->dev, "vbus");
        if (IS_ERR(ddata->vbus)) {
                error = PTR_ERR(ddata->vbus);
                goto out_err;
        }

        if (!ddata->vbus->indio_dev) {
                error = -ENXIO;
                goto out_err;
        }

        error = iio_get_channel_type(ddata->vbus, &type);
        if (error < 0)
                goto out_err;

        if (type != IIO_VOLTAGE) {
                error = -EINVAL;
                goto out_err;
        }

        return 0;

out_err:
        dev_err(ddata->dev, "could not initialize VBUS or ID IIO: %i\n",
                error);

        return error;
}

#ifdef CONFIG_OF
static const struct of_device_id cpcap_usb_phy_id_table[] = {
        {
                .compatible = "motorola,cpcap-usb-phy",
        },
        {
                .compatible = "motorola,mapphone-cpcap-usb-phy",
        },
        {},
};
MODULE_DEVICE_TABLE(of, cpcap_usb_phy_id_table);
#endif

static int cpcap_usb_phy_probe(struct platform_device *pdev)
{
        struct cpcap_phy_ddata *ddata;
        struct phy *generic_phy;
        struct phy_provider *phy_provider;
        struct usb_otg *otg;
        int error;

        ddata = devm_kzalloc(&pdev->dev, sizeof(*ddata), GFP_KERNEL);
        if (!ddata)
                return -ENOMEM;

        ddata->reg = dev_get_regmap(pdev->dev.parent, NULL);
        if (!ddata->reg)
                return -ENODEV;

        otg = devm_kzalloc(&pdev->dev, sizeof(*otg), GFP_KERNEL);
        if (!otg)
                return -ENOMEM;

        ddata->dev = &pdev->dev;
        ddata->phy.dev = ddata->dev;
        ddata->phy.label = "cpcap_usb_phy";
        ddata->phy.otg = otg;
        ddata->phy.type = USB_PHY_TYPE_USB2;
        otg->set_host = cpcap_usb_phy_set_host;
        otg->set_peripheral = cpcap_usb_phy_set_peripheral;
        otg->usb_phy = &ddata->phy;
        INIT_DELAYED_WORK(&ddata->detect_work, cpcap_usb_detect);
        platform_set_drvdata(pdev, ddata);

        ddata->vusb = devm_regulator_get(&pdev->dev, "vusb");
        if (IS_ERR(ddata->vusb))
                return PTR_ERR(ddata->vusb);

        error = regulator_enable(ddata->vusb);
        if (error)
                return error;

        generic_phy = devm_phy_create(ddata->dev, NULL, &ops);
        if (IS_ERR(generic_phy)) {
                error = PTR_ERR(generic_phy);
                goto out_reg_disable;
        }

        phy_set_drvdata(generic_phy, ddata);

        phy_provider = devm_of_phy_provider_register(ddata->dev,
                                                     of_phy_simple_xlate);
        if (IS_ERR(phy_provider)) {
                error = PTR_ERR(phy_provider);
                goto out_reg_disable;
        }

        error = cpcap_usb_init_optional_pins(ddata);
        if (error)
                goto out_reg_disable;

        cpcap_usb_init_optional_gpios(ddata);

        error = cpcap_usb_init_iio(ddata);
        if (error)
                goto out_reg_disable;

        error = cpcap_usb_init_interrupts(pdev, ddata);
        if (error)
                goto out_reg_disable;

        usb_add_phy_dev(&ddata->phy);
        atomic_set(&ddata->active, 1);
        schedule_delayed_work(&ddata->detect_work, msecs_to_jiffies(1));

        return 0;

out_reg_disable:
        regulator_disable(ddata->vusb);

        return error;
}

static void cpcap_usb_phy_remove(struct platform_device *pdev)
{
        struct cpcap_phy_ddata *ddata = platform_get_drvdata(pdev);
        int error;

        atomic_set(&ddata->active, 0);
        error = cpcap_usb_set_uart_mode(ddata);
        if (error)
                dev_err(ddata->dev, "could not set UART mode\n");

        cpcap_usb_try_musb_mailbox(ddata, MUSB_VBUS_OFF);

        usb_remove_phy(&ddata->phy);
        cancel_delayed_work_sync(&ddata->detect_work);
        regulator_disable(ddata->vusb);
}

static struct platform_driver cpcap_usb_phy_driver = {
        .probe          = cpcap_usb_phy_probe,
        .remove         = cpcap_usb_phy_remove,
        .driver         = {
                .name   = "cpcap-usb-phy",
                .of_match_table = of_match_ptr(cpcap_usb_phy_id_table),
        },
};

module_platform_driver(cpcap_usb_phy_driver);

MODULE_ALIAS("platform:cpcap_usb");
MODULE_AUTHOR("Tony Lindgren <tony@atomide.com>");
MODULE_DESCRIPTION("CPCAP usb phy driver");
MODULE_LICENSE("GPL v2");