extcon: axp288: Add axp288 extcon driver support

This patch adds the extcon support for AXP288 PMIC which
has the BC1.2 charger detection capability. Additionally
it also adds the USB mux switching support b/w SOC and PMIC
based on GPIO control.

Signed-off-by: Ramakrishna Pallala <ramakrishna.pallala@intel.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
[cw00.choi: Modify the log message to keep the consistent log message pattern]
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

4 files changed, 398 insertions, 0 deletions

diff --git a/drivers/extcon/Kconfig b/drivers/extcon/Kconfig
index bd10b6c6962d..b74e1f27688b 100644
--- a/drivers/extcon/Kconfig
+++ b/drivers/extcon/Kconfig
@@ -28,6 +28,13 @@ config EXTCON_ARIZONA
           with Wolfson Arizona devices. These are audio CODECs with
           advanced audio accessory detection support.
 
+config EXTCON_AXP288
+        tristate "X-Power AXP288 EXTCON support"
+        depends on MFD_AXP20X && USB_PHY
+        help
+          Say Y here to enable support for USB peripheral detection
+          and USB MUX switching by X-Power AXP288 PMIC.
+
 config EXTCON_GPIO
         tristate "GPIO extcon support"
         depends on GPIOLIB
diff --git a/drivers/extcon/Makefile b/drivers/extcon/Makefile
index 9204114791a3..ba787d04295b 100644
--- a/drivers/extcon/Makefile
+++ b/drivers/extcon/Makefile
@@ -5,6 +5,7 @@
 obj-$(CONFIG_EXTCON)            += extcon.o
 obj-$(CONFIG_EXTCON_ADC_JACK)   += extcon-adc-jack.o
 obj-$(CONFIG_EXTCON_ARIZONA)    += extcon-arizona.o
+obj-$(CONFIG_EXTCON_AXP288)     += extcon-axp288.o
 obj-$(CONFIG_EXTCON_GPIO)       += extcon-gpio.o
 obj-$(CONFIG_EXTCON_MAX14577)   += extcon-max14577.o
 obj-$(CONFIG_EXTCON_MAX77693)   += extcon-max77693.o
diff --git a/drivers/extcon/extcon-axp288.c b/drivers/extcon/extcon-axp288.c
new file mode 100644
index 000000000000..8299adb9b676
--- /dev/null
+++ b/drivers/extcon/extcon-axp288.c
@@ -0,0 +1,385 @@
+/*
+ * extcon-axp288.c - X-Power AXP288 PMIC extcon cable detection driver
+ *
+ * Copyright (C) 2015 Intel Corporation
+ * Author: Ramakrishna Pallala <ramakrishna.pallala@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.
+ *
+ * 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/kernel.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/usb/phy.h>
+#include <linux/notifier.h>
+#include <linux/extcon.h>
+#include <linux/regmap.h>
+#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
+#include <linux/mfd/axp20x.h>
+
+/* Power source status register */
+#define PS_STAT_VBUS_TRIGGER            BIT(0)
+#define PS_STAT_BAT_CHRG_DIR            BIT(2)
+#define PS_STAT_VBUS_ABOVE_VHOLD        BIT(3)
+#define PS_STAT_VBUS_VALID              BIT(4)
+#define PS_STAT_VBUS_PRESENT            BIT(5)
+
+/* BC module global register */
+#define BC_GLOBAL_RUN                   BIT(0)
+#define BC_GLOBAL_DET_STAT              BIT(2)
+#define BC_GLOBAL_DBP_TOUT              BIT(3)
+#define BC_GLOBAL_VLGC_COM_SEL          BIT(4)
+#define BC_GLOBAL_DCD_TOUT_MASK         (BIT(6)|BIT(5))
+#define BC_GLOBAL_DCD_TOUT_300MS        0
+#define BC_GLOBAL_DCD_TOUT_100MS        1
+#define BC_GLOBAL_DCD_TOUT_500MS        2
+#define BC_GLOBAL_DCD_TOUT_900MS        3
+#define BC_GLOBAL_DCD_DET_SEL           BIT(7)
+
+/* BC module vbus control and status register */
+#define VBUS_CNTL_DPDM_PD_EN            BIT(4)
+#define VBUS_CNTL_DPDM_FD_EN            BIT(5)
+#define VBUS_CNTL_FIRST_PO_STAT         BIT(6)
+
+/* BC USB status register */
+#define USB_STAT_BUS_STAT_MASK          (BIT(3)|BIT(2)|BIT(1)|BIT(0))
+#define USB_STAT_BUS_STAT_SHIFT         0
+#define USB_STAT_BUS_STAT_ATHD          0
+#define USB_STAT_BUS_STAT_CONN          1
+#define USB_STAT_BUS_STAT_SUSP          2
+#define USB_STAT_BUS_STAT_CONF          3
+#define USB_STAT_USB_SS_MODE            BIT(4)
+#define USB_STAT_DEAD_BAT_DET           BIT(6)
+#define USB_STAT_DBP_UNCFG              BIT(7)
+
+/* BC detect status register */
+#define DET_STAT_MASK                   (BIT(7)|BIT(6)|BIT(5))
+#define DET_STAT_SHIFT                  5
+#define DET_STAT_SDP                    1
+#define DET_STAT_CDP                    2
+#define DET_STAT_DCP                    3
+
+/* IRQ enable-1 register */
+#define PWRSRC_IRQ_CFG_MASK             (BIT(4)|BIT(3)|BIT(2))
+
+/* IRQ enable-6 register */
+#define BC12_IRQ_CFG_MASK               BIT(1)
+
+#define AXP288_EXTCON_SLOW_CHARGER              "SLOW-CHARGER"
+#define AXP288_EXTCON_DOWNSTREAM_CHARGER        "CHARGE-DOWNSTREAM"
+#define AXP288_EXTCON_FAST_CHARGER              "FAST-CHARGER"
+
+enum axp288_extcon_reg {
+        AXP288_PS_STAT_REG              = 0x00,
+        AXP288_PS_BOOT_REASON_REG       = 0x02,
+        AXP288_BC_GLOBAL_REG            = 0x2c,
+        AXP288_BC_VBUS_CNTL_REG         = 0x2d,
+        AXP288_BC_USB_STAT_REG          = 0x2e,
+        AXP288_BC_DET_STAT_REG          = 0x2f,
+        AXP288_PWRSRC_IRQ_CFG_REG       = 0x40,
+        AXP288_BC12_IRQ_CFG_REG         = 0x45,
+};
+
+enum axp288_mux_select {
+        EXTCON_GPIO_MUX_SEL_PMIC = 0,
+        EXTCON_GPIO_MUX_SEL_SOC,
+};
+
+enum axp288_extcon_irq {
+        VBUS_FALLING_IRQ = 0,
+        VBUS_RISING_IRQ,
+        MV_CHNG_IRQ,
+        BC_USB_CHNG_IRQ,
+        EXTCON_IRQ_END,
+};
+
+static const char *axp288_extcon_cables[] = {
+        AXP288_EXTCON_SLOW_CHARGER,
+        AXP288_EXTCON_DOWNSTREAM_CHARGER,
+        AXP288_EXTCON_FAST_CHARGER,
+        NULL,
+};
+
+struct axp288_extcon_info {
+        struct device *dev;
+        struct regmap *regmap;
+        struct regmap_irq_chip_data *regmap_irqc;
+        struct axp288_extcon_pdata *pdata;
+        int irq[EXTCON_IRQ_END];
+        struct extcon_dev *edev;
+        struct notifier_block extcon_nb;
+        struct usb_phy *otg;
+};
+
+/* Power up/down reason string array */
+static char *axp288_pwr_up_down_info[] = {
+        "Last wake caused by user pressing the power button",
+        "Last wake caused by a charger insertion",
+        "Last wake caused by a battery insertion",
+        "Last wake caused by SOC initiated global reset",
+        "Last wake caused by cold reset",
+        "Last shutdown caused by PMIC UVLO threshold",
+        "Last shutdown caused by SOC initiated cold off",
+        "Last shutdown caused by user pressing the power button",
+        NULL,
+};
+
+/*
+ * Decode and log the given "reset source indicator" (rsi)
+ * register and then clear it.
+ */
+static void axp288_extcon_log_rsi(struct axp288_extcon_info *info)
+{
+        char **rsi;
+        unsigned int val, i, clear_mask = 0;
+        int ret;
+
+        ret = regmap_read(info->regmap, AXP288_PS_BOOT_REASON_REG, &val);
+        for (i = 0, rsi = axp288_pwr_up_down_info; *rsi; rsi++, i++) {
+                if (val & BIT(i)) {
+                        dev_dbg(info->dev, "%s\n", *rsi);
+                        clear_mask |= BIT(i);
+                }
+        }
+
+        /* Clear the register value for next reboot (write 1 to clear bit) */
+        regmap_write(info->regmap, AXP288_PS_BOOT_REASON_REG, clear_mask);
+}
+
+static int axp288_handle_chrg_det_event(struct axp288_extcon_info *info)
+{
+        static bool notify_otg, notify_charger;
+        static char *cable;
+        int ret, stat, cfg, pwr_stat;
+        u8 chrg_type;
+        bool vbus_attach = false;
+
+        ret = regmap_read(info->regmap, AXP288_PS_STAT_REG, &pwr_stat);
+        if (ret < 0) {
+                dev_err(info->dev, "failed to read vbus status\n");
+                return ret;
+        }
+
+        vbus_attach = (pwr_stat & PS_STAT_VBUS_PRESENT);
+        if (!vbus_attach)
+                goto notify_otg;
+
+        /* Check charger detection completion status */
+        ret = regmap_read(info->regmap, AXP288_BC_GLOBAL_REG, &cfg);
+        if (ret < 0)
+                goto dev_det_ret;
+        if (cfg & BC_GLOBAL_DET_STAT) {
+                dev_dbg(info->dev, "can't complete the charger detection\n");
+                goto dev_det_ret;
+        }
+
+        ret = regmap_read(info->regmap, AXP288_BC_DET_STAT_REG, &stat);
+        if (ret < 0)
+                goto dev_det_ret;
+
+        chrg_type = (stat & DET_STAT_MASK) >> DET_STAT_SHIFT;
+
+        switch (chrg_type) {
+        case DET_STAT_SDP:
+                dev_dbg(info->dev, "sdp cable is connecetd\n");
+                notify_otg = true;
+                notify_charger = true;
+                cable = AXP288_EXTCON_SLOW_CHARGER;
+                break;
+        case DET_STAT_CDP:
+                dev_dbg(info->dev, "cdp cable is connecetd\n");
+                notify_otg = true;
+                notify_charger = true;
+                cable = AXP288_EXTCON_DOWNSTREAM_CHARGER;
+                break;
+        case DET_STAT_DCP:
+                dev_dbg(info->dev, "dcp cable is connecetd\n");
+                notify_charger = true;
+                cable = AXP288_EXTCON_FAST_CHARGER;
+                break;
+        default:
+                dev_warn(info->dev,
+                        "disconnect or unknown or ID event\n");
+        }
+
+notify_otg:
+        if (notify_otg) {
+                /*
+                 * If VBUS is absent Connect D+/D- lines to PMIC for BC
+                 * detection. Else connect them to SOC for USB communication.
+                 */
+                if (info->pdata->gpio_mux_cntl)
+                        gpiod_set_value(info->pdata->gpio_mux_cntl,
+                                vbus_attach ? EXTCON_GPIO_MUX_SEL_SOC
+                                                : EXTCON_GPIO_MUX_SEL_PMIC);
+
+                atomic_notifier_call_chain(&info->otg->notifier,
+                        vbus_attach ? USB_EVENT_VBUS : USB_EVENT_NONE, NULL);
+        }
+
+        if (notify_charger)
+                extcon_set_cable_state(info->edev, cable, vbus_attach);
+
+        /* Clear the flags on disconnect event */
+        if (!vbus_attach)
+                notify_otg = notify_charger = false;
+
+        return 0;
+
+dev_det_ret:
+        if (ret < 0)
+                dev_err(info->dev, "failed to detect BC Mod\n");
+
+        return ret;
+}
+
+static irqreturn_t axp288_extcon_isr(int irq, void *data)
+{
+        struct axp288_extcon_info *info = data;
+        int ret;
+
+        ret = axp288_handle_chrg_det_event(info);
+        if (ret < 0)
+                dev_err(info->dev, "failed to handle the interrupt\n");
+
+        return IRQ_HANDLED;
+}
+
+static void axp288_extcon_enable_irq(struct axp288_extcon_info *info)
+{
+        /* Unmask VBUS interrupt */
+        regmap_write(info->regmap, AXP288_PWRSRC_IRQ_CFG_REG,
+                                                PWRSRC_IRQ_CFG_MASK);
+        regmap_update_bits(info->regmap, AXP288_BC_GLOBAL_REG,
+                                                BC_GLOBAL_RUN, 0);
+        /* Unmask the BC1.2 complete interrupts */
+        regmap_write(info->regmap, AXP288_BC12_IRQ_CFG_REG, BC12_IRQ_CFG_MASK);
+        /* Enable the charger detection logic */
+        regmap_update_bits(info->regmap, AXP288_BC_GLOBAL_REG,
+                                        BC_GLOBAL_RUN, BC_GLOBAL_RUN);
+}
+
+static int axp288_extcon_probe(struct platform_device *pdev)
+{
+        struct axp288_extcon_info *info;
+        struct axp20x_dev *axp20x = dev_get_drvdata(pdev->dev.parent);
+        int ret, i, pirq, gpio;
+
+        info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
+        if (!info)
+                return -ENOMEM;
+
+        info->dev = &pdev->dev;
+        info->regmap = axp20x->regmap;
+        info->regmap_irqc = axp20x->regmap_irqc;
+        info->pdata = pdev->dev.platform_data;
+
+        if (!info->pdata) {
+                /* Try ACPI provided pdata via device properties */
+                if (!device_property_present(&pdev->dev,
+                                        "axp288_extcon_data\n"))
+                        dev_err(&pdev->dev, "failed to get platform data\n");
+                return -ENODEV;
+        }
+        platform_set_drvdata(pdev, info);
+
+        axp288_extcon_log_rsi(info);
+
+        /* Initialize extcon device */
+        info->edev = devm_extcon_dev_allocate(&pdev->dev,
+                                              axp288_extcon_cables);
+        if (IS_ERR(info->edev)) {
+                dev_err(&pdev->dev, "failed to allocate memory for extcon\n");
+                return PTR_ERR(info->edev);
+        }
+
+        /* Register extcon device */
+        ret = devm_extcon_dev_register(&pdev->dev, info->edev);
+        if (ret) {
+                dev_err(&pdev->dev, "failed to register extcon device\n");
+                return ret;
+        }
+
+        /* Get otg transceiver phy */
+        info->otg = usb_get_phy(USB_PHY_TYPE_USB2);
+        if (IS_ERR(info->otg)) {
+                dev_err(&pdev->dev, "failed to get otg transceiver\n");
+                return PTR_ERR(info->otg);
+        }
+
+        /* Set up gpio control for USB Mux */
+        if (info->pdata->gpio_mux_cntl) {
+                gpio = desc_to_gpio(info->pdata->gpio_mux_cntl);
+                ret = gpio_request(gpio, "USB_MUX");
+                if (ret < 0) {
+                        dev_err(&pdev->dev,
+                                "failed to request the gpio=%d\n", gpio);
+                        goto gpio_req_failed;
+                }
+                gpiod_direction_output(info->pdata->gpio_mux_cntl,
+                                                EXTCON_GPIO_MUX_SEL_PMIC);
+        }
+
+        for (i = 0; i < EXTCON_IRQ_END; i++) {
+                pirq = platform_get_irq(pdev, i);
+                info->irq[i] = regmap_irq_get_virq(info->regmap_irqc, pirq);
+                if (info->irq[i] < 0) {
+                        dev_err(&pdev->dev,
+                                "failed to get virtual interrupt=%d\n", pirq);
+                        ret = info->irq[i];
+                        goto gpio_req_failed;
+                }
+
+                ret = devm_request_threaded_irq(&pdev->dev, info->irq[i],
+                                NULL, axp288_extcon_isr,
+                                IRQF_ONESHOT | IRQF_NO_SUSPEND,
+                                pdev->name, info);
+                if (ret) {
+                        dev_err(&pdev->dev, "failed to request interrupt=%d\n",
+                                                        info->irq[i]);
+                        goto gpio_req_failed;
+                }
+        }
+
+        /* Enable interrupts */
+        axp288_extcon_enable_irq(info);
+
+        return 0;
+
+gpio_req_failed:
+        usb_put_phy(info->otg);
+        return ret;
+}
+
+static int axp288_extcon_remove(struct platform_device *pdev)
+{
+        struct axp288_extcon_info *info = platform_get_drvdata(pdev);
+
+        usb_put_phy(info->otg);
+        return 0;
+}
+
+static struct platform_driver axp288_extcon_driver = {
+        .probe = axp288_extcon_probe,
+        .remove = axp288_extcon_remove,
+        .driver = {
+                .name = "axp288_extcon",
+        },
+};
+module_platform_driver(axp288_extcon_driver);
+
+MODULE_AUTHOR("Ramakrishna Pallala <ramakrishna.pallala@intel.com>");
+MODULE_DESCRIPTION("X-Powers AXP288 extcon driver");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/mfd/axp20x.h b/include/linux/mfd/axp20x.h
index dfabd6db7ddf..4ed8071d062e 100644
--- a/include/linux/mfd/axp20x.h
+++ b/include/linux/mfd/axp20x.h
@@ -275,4 +275,9 @@ struct axp20x_fg_pdata {
         int thermistor_curve[MAX_THERM_CURVE_SIZE][2];
 };
 
+struct axp288_extcon_pdata {
+        /* GPIO pin control to switch D+/D- lines b/w PMIC and SOC */
+        struct gpio_desc *gpio_mux_cntl;
+};
+
 #endif /* __LINUX_MFD_AXP20X_H */