/*
   * twl6030_usb - TWL6030 USB transceiver, talking to OMAP OTG driver.
   *
   * Copyright (C) 2010 Texas Instruments Incorporated - http://www.ti.com
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   * Author: Hema HK <hemahk@ti.com>
   *
   * 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.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   *
   */
  
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/interrupt.h>
  #include <linux/platform_device.h>
  #include <linux/io.h>
  #include <linux/usb/musb-omap.h>
  #include <linux/usb/phy_companion.h>
  #include <linux/usb/omap_usb.h>
  #include <linux/i2c/twl.h>
  #include <linux/regulator/consumer.h>
  #include <linux/err.h>
  #include <linux/slab.h>
  #include <linux/delay.h>
  #include <linux/of.h>
  
  /* usb register definitions */
  #define USB_VENDOR_ID_LSB		0x00
  #define USB_VENDOR_ID_MSB		0x01
  #define USB_PRODUCT_ID_LSB		0x02
  #define USB_PRODUCT_ID_MSB		0x03
  #define USB_VBUS_CTRL_SET		0x04
  #define USB_VBUS_CTRL_CLR		0x05
  #define USB_ID_CTRL_SET			0x06
  #define USB_ID_CTRL_CLR			0x07
  #define USB_VBUS_INT_SRC		0x08
  #define USB_VBUS_INT_LATCH_SET		0x09
  #define USB_VBUS_INT_LATCH_CLR		0x0A
  #define USB_VBUS_INT_EN_LO_SET		0x0B
  #define USB_VBUS_INT_EN_LO_CLR		0x0C
  #define USB_VBUS_INT_EN_HI_SET		0x0D
  #define USB_VBUS_INT_EN_HI_CLR		0x0E
  #define USB_ID_INT_SRC			0x0F
  #define USB_ID_INT_LATCH_SET		0x10
  #define USB_ID_INT_LATCH_CLR		0x11
  
  #define USB_ID_INT_EN_LO_SET		0x12
  #define USB_ID_INT_EN_LO_CLR		0x13
  #define USB_ID_INT_EN_HI_SET		0x14
  #define USB_ID_INT_EN_HI_CLR		0x15
  #define USB_OTG_ADP_CTRL		0x16
  #define USB_OTG_ADP_HIGH		0x17
  #define USB_OTG_ADP_LOW			0x18
  #define USB_OTG_ADP_RISE		0x19
  #define USB_OTG_REVISION		0x1A
  
  /* to be moved to LDO */
  #define TWL6030_MISC2			0xE5
  #define TWL6030_CFG_LDO_PD2		0xF5
  #define TWL6030_BACKUP_REG		0xFA
  
  #define STS_HW_CONDITIONS		0x21
  
  /* In module TWL6030_MODULE_PM_MASTER */
  #define STS_HW_CONDITIONS		0x21
  #define STS_USB_ID			BIT(2)
  
  /* In module TWL6030_MODULE_PM_RECEIVER */
  #define VUSB_CFG_TRANS			0x71
  #define VUSB_CFG_STATE			0x72
  #define VUSB_CFG_VOLTAGE		0x73
  
  /* in module TWL6030_MODULE_MAIN_CHARGE */
  
  #define CHARGERUSB_CTRL1		0x8
  
  #define CONTROLLER_STAT1		0x03
  #define	VBUS_DET			BIT(2)
  
  struct twl6030_usb {
  	struct phy_companion	comparator;
  	struct device		*dev;
  
  	/* for vbus reporting with irqs disabled */
  	spinlock_t		lock;
  
  	struct regulator		*usb3v3;
  
  	/* used to set vbus, in atomic path */
  	struct work_struct	set_vbus_work;
  
  	int			irq1;
  	int			irq2;
  	enum omap_musb_vbus_id_status linkstat;
  	u8			asleep;
  	bool			irq_enabled;
  	bool			vbus_enable;
  	const char		*regulator;
  };
  
  #define	comparator_to_twl(x) container_of((x), struct twl6030_usb, comparator)
  
  /*-------------------------------------------------------------------------*/
  
  static inline int twl6030_writeb(struct twl6030_usb *twl, u8 module,
  						u8 data, u8 address)
  {
  	int ret = 0;
  
  	ret = twl_i2c_write_u8(module, data, address);
  	if (ret < 0)
  		dev_err(twl->dev,
  			"Write[0x%x] Error %d
  ", address, ret);
  	return ret;
  }
  
  static inline u8 twl6030_readb(struct twl6030_usb *twl, u8 module, u8 address)
  {
  	u8 data;
  	int ret;
  
  	ret = twl_i2c_read_u8(module, &data, address);
  	if (ret >= 0)
  		ret = data;
  	else
  		dev_err(twl->dev,
  			"readb[0x%x,0x%x] Error %d
  ",
  					module, address, ret);
  	return ret;
  }
  
  static int twl6030_start_srp(struct phy_companion *comparator)
  {
  	struct twl6030_usb *twl = comparator_to_twl(comparator);
  
  	twl6030_writeb(twl, TWL_MODULE_USB, 0x24, USB_VBUS_CTRL_SET);
  	twl6030_writeb(twl, TWL_MODULE_USB, 0x84, USB_VBUS_CTRL_SET);
  
  	mdelay(100);
  	twl6030_writeb(twl, TWL_MODULE_USB, 0xa0, USB_VBUS_CTRL_CLR);
  
  	return 0;
  }
  
  static int twl6030_usb_ldo_init(struct twl6030_usb *twl)
  {
  	/* Set to OTG_REV 1.3 and turn on the ID_WAKEUP_COMP */
  	twl6030_writeb(twl, TWL6030_MODULE_ID0 , 0x1, TWL6030_BACKUP_REG);
  
  	/* Program CFG_LDO_PD2 register and set VUSB bit */
  	twl6030_writeb(twl, TWL6030_MODULE_ID0 , 0x1, TWL6030_CFG_LDO_PD2);
  
  	/* Program MISC2 register and set bit VUSB_IN_VBAT */
  	twl6030_writeb(twl, TWL6030_MODULE_ID0 , 0x10, TWL6030_MISC2);
  
  	twl->usb3v3 = regulator_get(twl->dev, twl->regulator);
  	if (IS_ERR(twl->usb3v3))
  		return -ENODEV;
  
  	/* Program the USB_VBUS_CTRL_SET and set VBUS_ACT_COMP bit */
  	twl6030_writeb(twl, TWL_MODULE_USB, 0x4, USB_VBUS_CTRL_SET);
  
  	/*
  	 * Program the USB_ID_CTRL_SET register to enable GND drive
  	 * and the ID comparators
  	 */
  	twl6030_writeb(twl, TWL_MODULE_USB, 0x14, USB_ID_CTRL_SET);
  
  	return 0;
  }
  
  static ssize_t twl6030_usb_vbus_show(struct device *dev,
  			struct device_attribute *attr, char *buf)
  {
  	struct twl6030_usb *twl = dev_get_drvdata(dev);
  	unsigned long flags;
  	int ret = -EINVAL;
  
  	spin_lock_irqsave(&twl->lock, flags);
  
  	switch (twl->linkstat) {
  	case OMAP_MUSB_VBUS_VALID:
  	       ret = snprintf(buf, PAGE_SIZE, "vbus
  ");
  	       break;
  	case OMAP_MUSB_ID_GROUND:
  	       ret = snprintf(buf, PAGE_SIZE, "id
  ");
  	       break;
  	case OMAP_MUSB_VBUS_OFF:
  	       ret = snprintf(buf, PAGE_SIZE, "none
  ");
  	       break;
  	default:
  	       ret = snprintf(buf, PAGE_SIZE, "UNKNOWN
  ");
  	}
  	spin_unlock_irqrestore(&twl->lock, flags);
  
  	return ret;
  }
  static DEVICE_ATTR(vbus, 0444, twl6030_usb_vbus_show, NULL);
  
  static irqreturn_t twl6030_usb_irq(int irq, void *_twl)
  {
  	struct twl6030_usb *twl = _twl;
  	enum omap_musb_vbus_id_status status = OMAP_MUSB_UNKNOWN;
  	u8 vbus_state, hw_state;
  	int ret;
  
  	hw_state = twl6030_readb(twl, TWL6030_MODULE_ID0, STS_HW_CONDITIONS);
  
  	vbus_state = twl6030_readb(twl, TWL_MODULE_MAIN_CHARGE,
  						CONTROLLER_STAT1);
  	if (!(hw_state & STS_USB_ID)) {
  		if (vbus_state & VBUS_DET) {
  			ret = regulator_enable(twl->usb3v3);
  			if (ret)
  				dev_err(twl->dev, "Failed to enable usb3v3
  ");
  
  			twl->asleep = 1;
  			status = OMAP_MUSB_VBUS_VALID;
  			twl->linkstat = status;
  			omap_musb_mailbox(status);
  		} else {
  			if (twl->linkstat != OMAP_MUSB_UNKNOWN) {
  				status = OMAP_MUSB_VBUS_OFF;
  				twl->linkstat = status;
  				omap_musb_mailbox(status);
  				if (twl->asleep) {
  					regulator_disable(twl->usb3v3);
  					twl->asleep = 0;
  				}
  			}
  		}
  	}
  	sysfs_notify(&twl->dev->kobj, NULL, "vbus");
  
  	return IRQ_HANDLED;
  }
  
  static irqreturn_t twl6030_usbotg_irq(int irq, void *_twl)
  {
  	struct twl6030_usb *twl = _twl;
  	enum omap_musb_vbus_id_status status = OMAP_MUSB_UNKNOWN;
  	u8 hw_state;
  	int ret;
  
  	hw_state = twl6030_readb(twl, TWL6030_MODULE_ID0, STS_HW_CONDITIONS);
  
  	if (hw_state & STS_USB_ID) {
  		ret = regulator_enable(twl->usb3v3);
  		if (ret)
  			dev_err(twl->dev, "Failed to enable usb3v3
  ");
  
  		twl->asleep = 1;
  		twl6030_writeb(twl, TWL_MODULE_USB, 0x1, USB_ID_INT_EN_HI_CLR);
  		twl6030_writeb(twl, TWL_MODULE_USB, 0x10, USB_ID_INT_EN_HI_SET);
  		status = OMAP_MUSB_ID_GROUND;
  		twl->linkstat = status;
  		omap_musb_mailbox(status);
  	} else  {
  		twl6030_writeb(twl, TWL_MODULE_USB, 0x10, USB_ID_INT_EN_HI_CLR);
  		twl6030_writeb(twl, TWL_MODULE_USB, 0x1, USB_ID_INT_EN_HI_SET);
  	}
  	twl6030_writeb(twl, TWL_MODULE_USB, status, USB_ID_INT_LATCH_CLR);
  
  	return IRQ_HANDLED;
  }
  
  static int twl6030_enable_irq(struct twl6030_usb *twl)
  {
  	twl6030_writeb(twl, TWL_MODULE_USB, 0x1, USB_ID_INT_EN_HI_SET);
  	twl6030_interrupt_unmask(0x05, REG_INT_MSK_LINE_C);
  	twl6030_interrupt_unmask(0x05, REG_INT_MSK_STS_C);
  
  	twl6030_interrupt_unmask(TWL6030_CHARGER_CTRL_INT_MASK,
  				REG_INT_MSK_LINE_C);
  	twl6030_interrupt_unmask(TWL6030_CHARGER_CTRL_INT_MASK,
  				REG_INT_MSK_STS_C);
  	twl6030_usb_irq(twl->irq2, twl);
  	twl6030_usbotg_irq(twl->irq1, twl);
  
  	return 0;
  }
  
  static void otg_set_vbus_work(struct work_struct *data)
  {
  	struct twl6030_usb *twl = container_of(data, struct twl6030_usb,
  								set_vbus_work);
  
  	/*
  	 * Start driving VBUS. Set OPA_MODE bit in CHARGERUSB_CTRL1
  	 * register. This enables boost mode.
  	 */
  
  	if (twl->vbus_enable)
  		twl6030_writeb(twl, TWL_MODULE_MAIN_CHARGE , 0x40,
  							CHARGERUSB_CTRL1);
  	else
  		twl6030_writeb(twl, TWL_MODULE_MAIN_CHARGE , 0x00,
  							CHARGERUSB_CTRL1);
  }
  
  static int twl6030_set_vbus(struct phy_companion *comparator, bool enabled)
  {
  	struct twl6030_usb *twl = comparator_to_twl(comparator);
  
  	twl->vbus_enable = enabled;
  	schedule_work(&twl->set_vbus_work);
  
  	return 0;
  }
  
  static int twl6030_usb_probe(struct platform_device *pdev)
  {
  	u32 ret;
  	struct twl6030_usb	*twl;
  	int			status, err;
  	struct device_node	*np = pdev->dev.of_node;
  	struct device		*dev = &pdev->dev;
  	struct twl4030_usb_data	*pdata = dev_get_platdata(dev);
  
  	twl = devm_kzalloc(dev, sizeof(*twl), GFP_KERNEL);
  	if (!twl)
  		return -ENOMEM;
  
  	twl->dev		= &pdev->dev;
  	twl->irq1		= platform_get_irq(pdev, 0);
  	twl->irq2		= platform_get_irq(pdev, 1);
  	twl->linkstat		= OMAP_MUSB_UNKNOWN;
  
  	twl->comparator.set_vbus	= twl6030_set_vbus;
  	twl->comparator.start_srp	= twl6030_start_srp;
  
  	ret = omap_usb2_set_comparator(&twl->comparator);
  	if (ret == -ENODEV) {
  		dev_info(&pdev->dev, "phy not ready, deferring probe");
  		return -EPROBE_DEFER;
  	}
  
  	if (np) {
  		twl->regulator = "usb";
  	} else if (pdata) {
  		if (pdata->features & TWL6032_SUBCLASS)
  			twl->regulator = "ldousb";
  		else
  			twl->regulator = "vusb";
  	} else {
  		dev_err(&pdev->dev, "twl6030 initialized without pdata
  ");
  		return -EINVAL;
  	}
  
  	/* init spinlock for workqueue */
  	spin_lock_init(&twl->lock);
  
  	err = twl6030_usb_ldo_init(twl);
  	if (err) {
  		dev_err(&pdev->dev, "ldo init failed
  ");
  		return err;
  	}
  
  	platform_set_drvdata(pdev, twl);
  	if (device_create_file(&pdev->dev, &dev_attr_vbus))
  		dev_warn(&pdev->dev, "could not create sysfs file
  ");
  
  	INIT_WORK(&twl->set_vbus_work, otg_set_vbus_work);
  
  	twl->irq_enabled = true;
  	status = request_threaded_irq(twl->irq1, NULL, twl6030_usbotg_irq,
  			IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING | IRQF_ONESHOT,
  			"twl6030_usb", twl);
  	if (status < 0) {
  		dev_err(&pdev->dev, "can't get IRQ %d, err %d
  ",
  			twl->irq1, status);
  		device_remove_file(twl->dev, &dev_attr_vbus);
  		return status;
  	}
  
  	status = request_threaded_irq(twl->irq2, NULL, twl6030_usb_irq,
  			IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING | IRQF_ONESHOT,
  			"twl6030_usb", twl);
  	if (status < 0) {
  		dev_err(&pdev->dev, "can't get IRQ %d, err %d
  ",
  			twl->irq2, status);
  		free_irq(twl->irq1, twl);
  		device_remove_file(twl->dev, &dev_attr_vbus);
  		return status;
  	}
  
  	twl->asleep = 0;
  	twl6030_enable_irq(twl);
  	dev_info(&pdev->dev, "Initialized TWL6030 USB module
  ");
  
  	return 0;
  }
  
  static int twl6030_usb_remove(struct platform_device *pdev)
  {
  	struct twl6030_usb *twl = platform_get_drvdata(pdev);
  
  	twl6030_interrupt_mask(TWL6030_USBOTG_INT_MASK,
  		REG_INT_MSK_LINE_C);
  	twl6030_interrupt_mask(TWL6030_USBOTG_INT_MASK,
  			REG_INT_MSK_STS_C);
  	free_irq(twl->irq1, twl);
  	free_irq(twl->irq2, twl);
  	regulator_put(twl->usb3v3);
  	device_remove_file(twl->dev, &dev_attr_vbus);
  	cancel_work_sync(&twl->set_vbus_work);
  
  	return 0;
  }
  
  #ifdef CONFIG_OF
  static const struct of_device_id twl6030_usb_id_table[] = {
  	{ .compatible = "ti,twl6030-usb" },
  	{}
  };
  MODULE_DEVICE_TABLE(of, twl6030_usb_id_table);
  #endif
  
  static struct platform_driver twl6030_usb_driver = {
  	.probe		= twl6030_usb_probe,
  	.remove		= twl6030_usb_remove,
  	.driver		= {
  		.name	= "twl6030_usb",
  		.owner	= THIS_MODULE,
  		.of_match_table = of_match_ptr(twl6030_usb_id_table),
  	},
  };
  
  static int __init twl6030_usb_init(void)
  {
  	return platform_driver_register(&twl6030_usb_driver);
  }
  subsys_initcall(twl6030_usb_init);
  
  static void __exit twl6030_usb_exit(void)
  {
  	platform_driver_unregister(&twl6030_usb_driver);
  }
  module_exit(twl6030_usb_exit);
  
  MODULE_ALIAS("platform:twl6030_usb");
  MODULE_AUTHOR("Hema HK <hemahk@ti.com>");
  MODULE_DESCRIPTION("TWL6030 USB transceiver driver");
  MODULE_LICENSE("GPL");