text: // SPDX-License-Identifier: GPL-2.0+
  //
  // extcon-ptn5150.c - PTN5150 CC logic extcon driver to support USB detection
  //
  // Based on extcon-sm5502.c driver
  // Copyright (c) 2018-2019 by Vijai Kumar K
  // Author: Vijai Kumar K <vijaikumar.kanagarajan@gmail.com>
  
  #include <linux/err.h>
  #include <linux/i2c.h>
  #include <linux/interrupt.h>
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/regmap.h>
  #include <linux/slab.h>
  #include <linux/extcon-provider.h>
  #include <linux/gpio/consumer.h>
  
  /* PTN5150 registers */
  enum ptn5150_reg {
  	PTN5150_REG_DEVICE_ID = 0x01,
  	PTN5150_REG_CONTROL,
  	PTN5150_REG_INT_STATUS,
  	PTN5150_REG_CC_STATUS,
  	PTN5150_REG_CON_DET = 0x09,
  	PTN5150_REG_VCONN_STATUS,
  	PTN5150_REG_RESET,
  	PTN5150_REG_INT_MASK = 0x18,
  	PTN5150_REG_INT_REG_STATUS,
  	PTN5150_REG_END,
  };
  
  #define PTN5150_DFP_ATTACHED			0x1
  #define PTN5150_UFP_ATTACHED			0x2
  
  /* Define PTN5150 MASK/SHIFT constant */
  #define PTN5150_REG_DEVICE_ID_VENDOR_SHIFT	0
  #define PTN5150_REG_DEVICE_ID_VENDOR_MASK	\
  	(0x3 << PTN5150_REG_DEVICE_ID_VENDOR_SHIFT)
  
  #define PTN5150_REG_DEVICE_ID_VERSION_SHIFT	3
  #define PTN5150_REG_DEVICE_ID_VERSION_MASK	\
  	(0x1f << PTN5150_REG_DEVICE_ID_VERSION_SHIFT)
  
  #define PTN5150_REG_CC_PORT_ATTACHMENT_SHIFT	2
  #define PTN5150_REG_CC_PORT_ATTACHMENT_MASK	\
  	(0x7 << PTN5150_REG_CC_PORT_ATTACHMENT_SHIFT)
  
  #define PTN5150_REG_CC_VBUS_DETECTION_SHIFT	7
  #define PTN5150_REG_CC_VBUS_DETECTION_MASK	\
  	(0x1 << PTN5150_REG_CC_VBUS_DETECTION_SHIFT)
  
  #define PTN5150_REG_INT_CABLE_ATTACH_SHIFT	0
  #define PTN5150_REG_INT_CABLE_ATTACH_MASK	\
  	(0x1 << PTN5150_REG_INT_CABLE_ATTACH_SHIFT)
  
  #define PTN5150_REG_INT_CABLE_DETACH_SHIFT	1
  #define PTN5150_REG_INT_CABLE_DETACH_MASK	\
  	(0x1 << PTN5150_REG_CC_CABLE_DETACH_SHIFT)
  
  struct ptn5150_info {
  	struct device *dev;
  	struct extcon_dev *edev;
  	struct i2c_client *i2c;
  	struct regmap *regmap;
  	struct gpio_desc *int_gpiod;
  	struct gpio_desc *vbus_gpiod;
  	int irq;
  	struct work_struct irq_work;
  	struct mutex mutex;
  };
  
  /* List of detectable cables */
  static const unsigned int ptn5150_extcon_cable[] = {
  	EXTCON_USB,
  	EXTCON_USB_HOST,
  	EXTCON_NONE,
  };
  
  static const struct regmap_config ptn5150_regmap_config = {
  	.reg_bits	= 8,
  	.val_bits	= 8,
  	.max_register	= PTN5150_REG_END,
  };
  
  static void ptn5150_irq_work(struct work_struct *work)
  {
  	struct ptn5150_info *info = container_of(work,
  			struct ptn5150_info, irq_work);
  	int ret = 0;
  	unsigned int reg_data;
  	unsigned int int_status;
  
  	if (!info->edev)
  		return;
  
  	mutex_lock(&info->mutex);
  
  	ret = regmap_read(info->regmap, PTN5150_REG_CC_STATUS, &reg_data);
  	if (ret) {
  		dev_err(info->dev, "failed to read CC STATUS %d\n", ret);
  		mutex_unlock(&info->mutex);
  		return;
  	}
  
  	/* Clear interrupt. Read would clear the register */
  	ret = regmap_read(info->regmap, PTN5150_REG_INT_STATUS, &int_status);
  	if (ret) {
  		dev_err(info->dev, "failed to read INT STATUS %d\n", ret);
  		mutex_unlock(&info->mutex);
  		return;
  	}
  
  	if (int_status) {
  		unsigned int cable_attach;
  
  		cable_attach = int_status & PTN5150_REG_INT_CABLE_ATTACH_MASK;
  		if (cable_attach) {
  			unsigned int port_status;
  			unsigned int vbus;
  
  			port_status = ((reg_data &
  					PTN5150_REG_CC_PORT_ATTACHMENT_MASK) >>
  					PTN5150_REG_CC_PORT_ATTACHMENT_SHIFT);
  
  			switch (port_status) {
  			case PTN5150_DFP_ATTACHED:
  				extcon_set_state_sync(info->edev,
  						EXTCON_USB_HOST, false);
  				gpiod_set_value(info->vbus_gpiod, 0);
  				extcon_set_state_sync(info->edev, EXTCON_USB,
  						true);
  				break;
  			case PTN5150_UFP_ATTACHED:
  				extcon_set_state_sync(info->edev, EXTCON_USB,
  						false);
  				vbus = ((reg_data &
  					PTN5150_REG_CC_VBUS_DETECTION_MASK) >>
  					PTN5150_REG_CC_VBUS_DETECTION_SHIFT);
  				if (vbus)
  					gpiod_set_value(info->vbus_gpiod, 0);
  				else
  					gpiod_set_value(info->vbus_gpiod, 1);
  
  				extcon_set_state_sync(info->edev,
  						EXTCON_USB_HOST, true);
  				break;
  			default:
  				dev_err(info->dev,
  					"Unknown Port status : %x\n",
  					port_status);
  				break;
  			}
  		} else {
  			extcon_set_state_sync(info->edev,
  					EXTCON_USB_HOST, false);
  			extcon_set_state_sync(info->edev,
  					EXTCON_USB, false);
  			gpiod_set_value(info->vbus_gpiod, 0);
  		}
  	}
  
  	/* Clear interrupt. Read would clear the register */
  	ret = regmap_read(info->regmap, PTN5150_REG_INT_REG_STATUS,
  			&int_status);
  	if (ret) {
  		dev_err(info->dev,
  			"failed to read INT REG STATUS %d\n", ret);
  		mutex_unlock(&info->mutex);
  		return;
  	}
  
  	mutex_unlock(&info->mutex);
  }
  
  
  static irqreturn_t ptn5150_irq_handler(int irq, void *data)
  {
  	struct ptn5150_info *info = data;
  
  	schedule_work(&info->irq_work);
  
  	return IRQ_HANDLED;
  }
  
  static int ptn5150_init_dev_type(struct ptn5150_info *info)
  {
  	unsigned int reg_data, vendor_id, version_id;
  	int ret;
  
  	ret = regmap_read(info->regmap, PTN5150_REG_DEVICE_ID, &reg_data);
  	if (ret) {
  		dev_err(info->dev, "failed to read DEVICE_ID %d\n", ret);
  		return -EINVAL;
  	}
  
  	vendor_id = ((reg_data & PTN5150_REG_DEVICE_ID_VENDOR_MASK) >>
  				PTN5150_REG_DEVICE_ID_VENDOR_SHIFT);
  	version_id = ((reg_data & PTN5150_REG_DEVICE_ID_VERSION_MASK) >>
  				PTN5150_REG_DEVICE_ID_VERSION_SHIFT);
  
  	dev_info(info->dev, "Device type: version: 0x%x, vendor: 0x%x\n",
  			    version_id, vendor_id);
  
  	/* Clear any existing interrupts */
  	ret = regmap_read(info->regmap, PTN5150_REG_INT_STATUS, &reg_data);
  	if (ret) {
  		dev_err(info->dev,
  			"failed to read PTN5150_REG_INT_STATUS %d\n",
  			ret);
  		return -EINVAL;
  	}
  
  	ret = regmap_read(info->regmap, PTN5150_REG_INT_REG_STATUS, &reg_data);
  	if (ret) {
  		dev_err(info->dev,
  			"failed to read PTN5150_REG_INT_REG_STATUS %d\n", ret);
  		return -EINVAL;
  	}
  
  	return 0;
  }
  
  static int ptn5150_i2c_probe(struct i2c_client *i2c,
  				 const struct i2c_device_id *id)
  {
  	struct device *dev = &i2c->dev;
  	struct device_node *np = i2c->dev.of_node;
  	struct ptn5150_info *info;
  	int ret;
  
  	if (!np)
  		return -EINVAL;
  
  	info = devm_kzalloc(&i2c->dev, sizeof(*info), GFP_KERNEL);
  	if (!info)
  		return -ENOMEM;
  	i2c_set_clientdata(i2c, info);
  
  	info->dev = &i2c->dev;
  	info->i2c = i2c;
  	info->int_gpiod = devm_gpiod_get(&i2c->dev, "int", GPIOD_IN);
  	if (IS_ERR(info->int_gpiod)) {
  		dev_err(dev, "failed to get INT GPIO\n");
  		return PTR_ERR(info->int_gpiod);
  	}
  	info->vbus_gpiod = devm_gpiod_get(&i2c->dev, "vbus", GPIOD_IN);
  	if (IS_ERR(info->vbus_gpiod)) {
  		dev_err(dev, "failed to get VBUS GPIO\n");
  		return PTR_ERR(info->vbus_gpiod);
  	}
  	ret = gpiod_direction_output(info->vbus_gpiod, 0);
  	if (ret) {
  		dev_err(dev, "failed to set VBUS GPIO direction\n");
  		return -EINVAL;
  	}
  
  	mutex_init(&info->mutex);
  
  	INIT_WORK(&info->irq_work, ptn5150_irq_work);
  
  	info->regmap = devm_regmap_init_i2c(i2c, &ptn5150_regmap_config);
  	if (IS_ERR(info->regmap)) {
  		ret = PTR_ERR(info->regmap);
  		dev_err(info->dev, "failed to allocate register map: %d\n",
  				   ret);
  		return ret;
  	}
  
  	if (info->int_gpiod) {
  		info->irq = gpiod_to_irq(info->int_gpiod);
  		if (info->irq < 0) {
  			dev_err(dev, "failed to get INTB IRQ\n");
  			return info->irq;
  		}
  
  		ret = devm_request_threaded_irq(dev, info->irq, NULL,
  						ptn5150_irq_handler,
  						IRQF_TRIGGER_FALLING |
  						IRQF_ONESHOT,
  						i2c->name, info);
  		if (ret < 0) {
  			dev_err(dev, "failed to request handler for INTB IRQ\n");
  			return ret;
  		}
  	}
  
  	/* Allocate extcon device */
  	info->edev = devm_extcon_dev_allocate(info->dev, ptn5150_extcon_cable);
  	if (IS_ERR(info->edev)) {
  		dev_err(info->dev, "failed to allocate memory for extcon\n");
  		return -ENOMEM;
  	}
  
  	/* Register extcon device */
  	ret = devm_extcon_dev_register(info->dev, info->edev);
  	if (ret) {
  		dev_err(info->dev, "failed to register extcon device\n");
  		return ret;
  	}
  
  	/* Initialize PTN5150 device and print vendor id and version id */
  	ret = ptn5150_init_dev_type(info);
  	if (ret)
  		return -EINVAL;
  
  	return 0;
  }
  
  static const struct of_device_id ptn5150_dt_match[] = {
  	{ .compatible = "nxp,ptn5150" },
  	{ },
  };
  MODULE_DEVICE_TABLE(of, ptn5150_dt_match);
  
  static const struct i2c_device_id ptn5150_i2c_id[] = {
  	{ "ptn5150", 0 },
  	{ }
  };
  MODULE_DEVICE_TABLE(i2c, ptn5150_i2c_id);
  
  static struct i2c_driver ptn5150_i2c_driver = {
  	.driver		= {
  		.name	= "ptn5150",
  		.of_match_table = ptn5150_dt_match,
  	},
  	.probe	= ptn5150_i2c_probe,
  	.id_table = ptn5150_i2c_id,
  };
  
  static int __init ptn5150_i2c_init(void)
  {
  	return i2c_add_driver(&ptn5150_i2c_driver);
  }
  subsys_initcall(ptn5150_i2c_init);
  
  MODULE_DESCRIPTION("NXP PTN5150 CC logic Extcon driver");
  MODULE_AUTHOR("Vijai Kumar K <vijaikumar.kanagarajan@gmail.com>");
  MODULE_LICENSE("GPL v2");
  