drivers/soc/qcom/eud.c - kernel/msm-4.9 - Gitiles

 /* Copyright (c) 2016-2017, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
  * only 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/kernel.h>
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/interrupt.h>
 #include <linux/err.h>
 #include <linux/platform_device.h>
 #include <linux/extcon.h>
 #include <linux/delay.h>
 #include <linux/sysfs.h>
 #include <linux/io.h>
 #include <linux/bitops.h>
 #include <linux/tty.h>
 #include <linux/tty_flip.h>
 #include <linux/serial_core.h>
 #include <linux/serial.h>
 #include <linux/workqueue.h>

 #define EUD_ENABLE_CMD 1
 #define EUD_DISABLE_CMD 0

 #define EUD_REG_COM_TX_ID	0x0000
 #define EUD_REG_COM_TX_LEN	0x0004
 #define EUD_REG_COM_TX_DAT	0x0008
 #define EUD_REG_COM_RX_ID	0x000C
 #define EUD_REG_COM_RX_LEN	0x0010
 #define EUD_REG_COM_RX_DAT	0x0014
 #define EUD_REG_INT1_EN_MASK	0x0024
 #define EUD_REG_INT_STATUS_1	0x0044
 #define EUD_REG_CTL_OUT_1	0x0074
 #define EUD_REG_VBUS_INT_CLR	0x0080
 #define EUD_REG_CHGR_INT_CLR	0x0084
 #define EUD_REG_CSR_EUD_EN	0x1014
 #define EUD_REG_SW_ATTACH_DET	0x1018

 #define EUD_INT_RX		BIT(0)
 #define EUD_INT_TX		BIT(1)
 #define EUD_INT_VBUS		BIT(2)
 #define EUD_INT_CHGR		BIT(3)
 #define EUD_INT_SAFE_MODE	BIT(4)
 #define EUD_INT_ALL		(EUD_INT_RX | EUD_INT_TX | \
 				EUD_INT_VBUS | EUD_INT_CHGR | \
 				EUD_INT_SAFE_MODE)

 #define EUD_NR			1
 #define EUD_CONSOLE		NULL
 #define UART_ID			0x90
 #define MAX_FIFO_SIZE		14

 struct eud_chip {
 	struct device			*dev;
 	int				eud_irq;
 	unsigned int			extcon_id;
 	unsigned int			int_status;
 	bool				usb_attach;
 	bool				chgr_enable;
 	void __iomem			*eud_reg_base;
 	struct extcon_dev		*extcon;
 	struct uart_port		port;
 	struct work_struct		eud_work;
 };

 static const unsigned int eud_extcon_cable[] = {
 	EXTCON_USB,
 	EXTCON_CHG_USB_SDP,
 	EXTCON_NONE,
 };

 /*
  * On the kernel command line specify eud.enable=1 to enable EUD.
  * EUD is disabled by default.
  */
 static int enable;
 static struct platform_device *eud_private;

 static void enable_eud(struct platform_device *pdev)
 {
 	struct eud_chip *priv = platform_get_drvdata(pdev);

 	/* write into CSR to enable EUD */
 	writel_relaxed(BIT(0), priv->eud_reg_base + EUD_REG_CSR_EUD_EN);
 	/* Enable vbus, chgr & safe mode warning interrupts */
 	writel_relaxed(EUD_INT_VBUS | EUD_INT_CHGR | EUD_INT_SAFE_MODE,
 			priv->eud_reg_base + EUD_REG_INT1_EN_MASK);

 	/* Ensure Register Writes Complete */
 	wmb();

 	dev_dbg(&pdev->dev, "%s: EUD Enabled!\n", __func__);
 }

 static void disable_eud(struct platform_device *pdev)
 {
 	struct eud_chip *priv = platform_get_drvdata(pdev);

 	/* write into CSR to disable EUD */
 	writel_relaxed(0, priv->eud_reg_base + EUD_REG_CSR_EUD_EN);
 	dev_dbg(&pdev->dev, "%s: EUD Disabled!\n", __func__);
 }

 static int param_eud_set(const char *val, const struct kernel_param *kp)
 {
 	int enable = 0;

 	if (sscanf(val, "%du", &enable) != 1)
 		return -EINVAL;

 	if (enable != EUD_ENABLE_CMD && enable != EUD_DISABLE_CMD)
 		return -EINVAL;

 	if (enable == EUD_ENABLE_CMD) {
 		pr_debug("%s: Enbling EUD\n", __func__);
 		enable_eud(eud_private);
 	} else if (enable == EUD_DISABLE_CMD) {
 		pr_debug("%s: Disabling EUD\n", __func__);
 		disable_eud(eud_private);
 	}

 	*((uint *)kp->arg) = enable;
 	return 0;
 }

 static const struct kernel_param_ops eud_param_ops = {
 	.set = param_eud_set,
 	.get = param_get_int,
 };

 module_param_cb(enable, &eud_param_ops, &enable, 0644);

 static void eud_event_notifier(struct work_struct *eud_work)
 {
 	struct eud_chip *chip = container_of(eud_work, struct eud_chip,
 					eud_work);

 	if (chip->int_status == EUD_INT_VBUS)
 		extcon_set_state_sync(chip->extcon, chip->extcon_id,
 					chip->usb_attach);
 	else if (chip->int_status == EUD_INT_CHGR)
 		extcon_set_state_sync(chip->extcon, chip->extcon_id,
 					chip->chgr_enable);
 }

 static void usb_attach_detach(struct eud_chip *chip)
 {
 	u32 reg;

 	chip->extcon_id = EXTCON_USB;
 	/* read ctl_out_1[4] to find USB attach or detach event */
 	reg = readl_relaxed(chip->eud_reg_base + EUD_REG_CTL_OUT_1);
 	if (reg & BIT(4))
 		chip->usb_attach = true;
 	else
 		chip->usb_attach = false;

 	schedule_work(&chip->eud_work);

 	/* set and clear vbus_int_clr[0] to clear interrupt */
 	writel_relaxed(BIT(0), chip->eud_reg_base + EUD_REG_VBUS_INT_CLR);
 	/* Ensure Register Writes Complete */
 	wmb();
 	writel_relaxed(0, chip->eud_reg_base + EUD_REG_VBUS_INT_CLR);
 }

 static void chgr_enable_disable(struct eud_chip *chip)
 {
 	u32 reg;

 	chip->extcon_id = EXTCON_CHG_USB_SDP;
 	/* read ctl_out_1[6] to find charger enable or disable event */
 	reg = readl_relaxed(chip->eud_reg_base + EUD_REG_CTL_OUT_1);
 	if (reg & BIT(6))
 		chip->chgr_enable = true;
 	else
 		chip->chgr_enable = false;

 	schedule_work(&chip->eud_work);

 	/* set and clear chgr_int_clr[0] to clear interrupt */
 	writel_relaxed(BIT(0), chip->eud_reg_base + EUD_REG_CHGR_INT_CLR);
 	/* Ensure Register Writes Complete */
 	wmb();
 	writel_relaxed(0, chip->eud_reg_base + EUD_REG_CHGR_INT_CLR);
 }

 static void pet_eud(struct eud_chip *chip)
 {
 	u32 reg;

 	/* read sw_attach_det[0] to find attach/detach event */
 	reg = readl_relaxed(chip->eud_reg_base + EUD_REG_SW_ATTACH_DET);
 	if (reg & BIT(0)) {
 		/* Detach & Attach pet for EUD */
 		writel_relaxed(0, chip->eud_reg_base + EUD_REG_SW_ATTACH_DET);
 		/* Ensure Register Writes Complete */
 		wmb();
 		/* Delay to make sure detach pet is done before attach pet */
 		udelay(100);
 		writel_relaxed(BIT(0), chip->eud_reg_base +
 					EUD_REG_SW_ATTACH_DET);
 		/* Ensure Register Writes Complete */
 		wmb();
 	} else {
 		/* Attach pet for EUD */
 		writel_relaxed(BIT(0), chip->eud_reg_base +
 					EUD_REG_SW_ATTACH_DET);
 		/* Ensure Register Writes Complete */
 		wmb();
 	}
 }

 static unsigned int eud_tx_empty(struct uart_port *port)
 {
 	u32 reg;

 	/* read status register and cross check for Tx interrupt */
 	reg = readl_relaxed(port->membase + EUD_REG_INT_STATUS_1);
 	if (reg & EUD_INT_TX)
 		return TIOCSER_TEMT;
 	else
 		return 0;
 }

 static void eud_stop_tx(struct uart_port *port)
 {
 	/* Disable Tx interrupt */
 	writel_relaxed(~EUD_INT_TX, port->membase + EUD_REG_INT_STATUS_1);
 	/* Ensure Register Writes Complete */
 	wmb();
 }

 static void eud_start_tx(struct uart_port *port)
 {
 	/* Enable Tx interrupt */
 	writel_relaxed(EUD_INT_TX, port->membase + EUD_REG_INT_STATUS_1);
 	/* Ensure Register Writes Complete */
 	wmb();
 }

 static void eud_stop_rx(struct uart_port *port)
 {
 	/* Disable Rx interrupt */
 	writel_relaxed(~EUD_INT_RX, port->membase + EUD_REG_INT_STATUS_1);
 	/* Ensure Register Writes Complete */
 	wmb();
 }

 static int eud_startup(struct uart_port *port)
 {
 	/* Enable Rx interrupt */
 	writel_relaxed(EUD_INT_RX, port->membase + EUD_REG_INT_STATUS_1);
 	/* Ensure Register Writes Complete */
 	wmb();
 	return 0;
 }

 static void eud_shutdown(struct uart_port *port)
 {
 	/* Disable both Tx & Rx interrupts */
 	writel_relaxed(~EUD_INT_TX | ~EUD_INT_RX,
 			port->membase + EUD_REG_INT_STATUS_1);
 	/* Ensure Register Writes Complete */
 	wmb();
 }

 static const char *eud_type(struct uart_port *port)
 {
 	return (port->type == PORT_EUD_UART) ? "EUD UART" : NULL;
 }

 static int eud_request_port(struct uart_port *port)
 {
 	/* Nothing to request */
 	return 0;
 }

 static void eud_release_port(struct uart_port *port)
 {
 	/* Nothing to release */
 }

 static void eud_config_port(struct uart_port *port, int flags)
 {
 	/* set port type, clear Tx and Rx interrupts */
 	port->type = PORT_EUD_UART;
 	writel_relaxed(~EUD_INT_TX | ~EUD_INT_RX,
 			port->membase + EUD_REG_INT_STATUS_1);
 	/* Ensure Register Writes Complete */
 	wmb();
 }

 static int eud_verify_port(struct uart_port *port,
 				       struct serial_struct *ser)
 {
 	if (ser->type != PORT_UNKNOWN && ser->type != PORT_EUD_UART)
 		return -EINVAL;
 	return 0;
 }

 /* serial functions supported */
 static const struct uart_ops eud_uart_ops = {
 	.tx_empty	= eud_tx_empty,
 	.stop_tx	= eud_stop_tx,
 	.start_tx	= eud_start_tx,
 	.stop_rx	= eud_stop_rx,
 	.startup	= eud_startup,
 	.shutdown	= eud_shutdown,
 	.type		= eud_type,
 	.release_port	= eud_release_port,
 	.request_port	= eud_request_port,
 	.config_port	= eud_config_port,
 	.verify_port	= eud_verify_port,
 };

 static struct uart_driver eud_uart_driver = {
 	.owner		= THIS_MODULE,
 	.driver_name	= "msm-eud",
 	.dev_name	= "ttyEUD",
 	.nr		= EUD_NR,
 	.cons		= EUD_CONSOLE,
 };

 static void eud_uart_rx(struct eud_chip *chip)
 {
 	struct uart_port *port = &chip->port;
 	u32 reg;
 	unsigned int len;
 	unsigned char ch, flag;
 	int i;

 	reg = readl_relaxed(chip->eud_reg_base + EUD_REG_COM_RX_ID);
 	if (reg != UART_ID) {
 		dev_err(chip->dev, "Rx isn't for us!\n");
 		return;
 	}
 	/* Read Rx Len & Data registers */
 	spin_lock(&port->lock);
 	len = readl_relaxed(chip->eud_reg_base + EUD_REG_COM_RX_LEN);
 	for (i = 0; i < len; i++) {
 		ch = readl_relaxed(chip->eud_reg_base + EUD_REG_COM_RX_DAT);
 		flag = TTY_NORMAL;
 		port->icount.rx++;

 		if (uart_handle_sysrq_char(port, ch))
 			continue;
 		uart_insert_char(port, 0, 0, ch, flag);
 	}

 	spin_unlock(&port->lock);
 	tty_flip_buffer_push(&port->state->port);
 }

 static void eud_uart_tx(struct eud_chip *chip)
 {
 	struct uart_port *port = &chip->port;
 	struct circ_buf *xmit = &port->state->xmit;
 	unsigned int len;
 	u32 reg;

 	writel_relaxed(UART_ID, chip->eud_reg_base + EUD_REG_COM_TX_ID);
 	reg = readl_relaxed(chip->eud_reg_base + EUD_REG_COM_TX_ID);
 	if (reg != UART_ID) {
 		dev_err(chip->dev, "Tx isn't for us!\n");
 		return;
 	}
 	/* Write to Tx Len & Data registers */
 	spin_lock(&port->lock);
 	len = uart_circ_chars_pending(xmit);
 	if (len > 0) {
 		if (len > port->fifosize)
 			len = port->fifosize;
 		while (len--) {
 			writel_relaxed(xmit->buf[xmit->tail],
 			       port->membase + EUD_REG_COM_TX_DAT);
 			xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 			port->icount.tx++;
 		}
 	}
 	spin_unlock(&port->lock);
 }

 static irqreturn_t handle_eud_irq(int irq, void *data)
 {
 	struct eud_chip *chip = data;
 	u32 reg;
 	u32 int_mask_en1 = readl_relaxed(chip->eud_reg_base +
 					EUD_REG_INT1_EN_MASK);

 	/* read status register and find out which interrupt triggered */
 	reg = readl_relaxed(chip->eud_reg_base + EUD_REG_INT_STATUS_1);
 	if (reg & EUD_INT_RX) {
 		dev_dbg(chip->dev, "EUD RX Interrupt!\n");
 		eud_uart_rx(chip);
 	} else if ((reg & EUD_INT_TX) & int_mask_en1) {
 		dev_dbg(chip->dev, "EUD TX Interrupt!\n");
 		eud_uart_tx(chip);
 	} else if (reg & EUD_INT_VBUS) {
 		dev_dbg(chip->dev, "EUD VBUS Interrupt!\n");
 		chip->int_status = EUD_INT_VBUS;
 		usb_attach_detach(chip);
 	} else if (reg & EUD_INT_CHGR) {
 		dev_dbg(chip->dev, "EUD CHGR Interrupt!\n");
 		chip->int_status = EUD_INT_CHGR;
 		chgr_enable_disable(chip);
 	} else if (reg & EUD_INT_SAFE_MODE) {
 		dev_dbg(chip->dev, "EUD SAFE MODE Interrupt!\n");
 		pet_eud(chip);
 	} else {
 		dev_dbg(chip->dev, "Unknown/spurious EUD Interrupt!\n");
 		return IRQ_NONE;
 	}

 	return IRQ_HANDLED;
 }

 static int msm_eud_probe(struct platform_device *pdev)
 {
 	struct eud_chip *chip;
 	struct uart_port *port;
 	struct resource *res;
 	int ret;

 	chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
 	if (!chip) {
 		ret = -ENOMEM;
 		return ret;
 	}

 	platform_set_drvdata(pdev, chip);

 	chip->extcon = devm_extcon_dev_allocate(&pdev->dev, eud_extcon_cable);
 	if (IS_ERR(chip->extcon)) {
 		dev_err(chip->dev, "failed to allocate extcon device\n");
 		return PTR_ERR(chip->extcon);
 	}

 	ret = devm_extcon_dev_register(&pdev->dev, chip->extcon);
 	if (ret) {
 		dev_err(chip->dev, "failed to register extcon device\n");
 		return ret;
 	}

 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "eud_base");
 	if (!res) {
 		dev_err(chip->dev, "%s: failed to get resource eud_base\n",
 					__func__);
 		ret = -ENOMEM;
 		return ret;
 	}

 	chip->eud_reg_base = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(chip->eud_reg_base))
 		return PTR_ERR(chip->eud_reg_base);

 	chip->eud_irq = platform_get_irq_byname(pdev, "eud_irq");

 	ret = devm_request_irq(&pdev->dev, chip->eud_irq, handle_eud_irq,
 				IRQF_TRIGGER_HIGH, "eud_irq", chip);
 	if (ret) {
 		dev_err(chip->dev, "request failed for eud irq\n");
 		return ret;
 	}

 	device_init_wakeup(&pdev->dev, true);
 	enable_irq_wake(chip->eud_irq);

 	INIT_WORK(&chip->eud_work, eud_event_notifier);

 	port = &chip->port;
 	port->line = pdev->id;
 	port->type = PORT_EUD_UART;
 	port->dev = chip->dev;
 	port->fifosize = MAX_FIFO_SIZE;
 	port->iotype = SERIAL_IO_MEM;
 	port->flags = UPF_BOOT_AUTOCONF;
 	port->membase = chip->eud_reg_base;
 	port->irq = chip->eud_irq;
 	port->ops = &eud_uart_ops;

 	ret = uart_add_one_port(&eud_uart_driver, port);
 	if (!ret) {
 		dev_err(chip->dev, "failed to add uart port!\n");
 		return ret;
 	}

 	eud_private = pdev;

 	/* Enable EUD */
 	if (enable)
 		enable_eud(pdev);

 	return 0;
 }

 static int msm_eud_remove(struct platform_device *pdev)
 {
 	struct eud_chip *chip = platform_get_drvdata(pdev);
 	struct uart_port *port = &chip->port;

 	uart_remove_one_port(&eud_uart_driver, port);
 	device_init_wakeup(chip->dev, false);

 	return 0;
 }

 static const struct of_device_id msm_eud_dt_match[] = {
 	{.compatible = "qcom,msm-eud"},
 	{},
 };
 MODULE_DEVICE_TABLE(of, msm_eud_dt_match);

 static struct platform_driver msm_eud_driver = {
 	.probe		= msm_eud_probe,
 	.remove		= msm_eud_remove,
 	.driver		= {
 		.name		= "msm-eud",
 		.owner		= THIS_MODULE,
 		.of_match_table = msm_eud_dt_match,
 	},
 };

 static int __init msm_eud_init(void)
 {
 	int ret;

 	ret = uart_register_driver(&eud_uart_driver);
 	if (ret) {
 		pr_err("%s: Failed to register EUD UART driver\n",
 			__func__);
 		return ret;
 	}

 	ret = platform_driver_register(&msm_eud_driver);
 	if (ret) {
 		pr_err("%s: Failed to register EUD driver\n",
 			__func__);
 		uart_unregister_driver(&eud_uart_driver);
 		return ret;
 	}

 	return 0;
 }
 module_init(msm_eud_init);

 static void __exit msm_eud_exit(void)
 {
 	platform_driver_unregister(&msm_eud_driver);
 	uart_unregister_driver(&eud_uart_driver);
 }
 module_exit(msm_eud_exit);

 MODULE_DESCRIPTION("QTI EUD driver");
 MODULE_LICENSE("GPL v2");
	/* Copyright (c) 2016-2017, The Linux Foundation. All rights reserved.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 and
	* only 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/kernel.h>
	#include <linux/module.h>
	#include <linux/slab.h>
	#include <linux/interrupt.h>
	#include <linux/err.h>
	#include <linux/platform_device.h>
	#include <linux/extcon.h>
	#include <linux/delay.h>
	#include <linux/sysfs.h>
	#include <linux/io.h>
	#include <linux/bitops.h>
	#include <linux/tty.h>
	#include <linux/tty_flip.h>
	#include <linux/serial_core.h>
	#include <linux/serial.h>
	#include <linux/workqueue.h>

	#define EUD_ENABLE_CMD 1
	#define EUD_DISABLE_CMD 0

	#define EUD_REG_COM_TX_ID 0x0000
	#define EUD_REG_COM_TX_LEN 0x0004
	#define EUD_REG_COM_TX_DAT 0x0008
	#define EUD_REG_COM_RX_ID 0x000C
	#define EUD_REG_COM_RX_LEN 0x0010
	#define EUD_REG_COM_RX_DAT 0x0014
	#define EUD_REG_INT1_EN_MASK 0x0024
	#define EUD_REG_INT_STATUS_1 0x0044
	#define EUD_REG_CTL_OUT_1 0x0074
	#define EUD_REG_VBUS_INT_CLR 0x0080
	#define EUD_REG_CHGR_INT_CLR 0x0084
	#define EUD_REG_CSR_EUD_EN 0x1014
	#define EUD_REG_SW_ATTACH_DET 0x1018

	#define EUD_INT_RX BIT(0)
	#define EUD_INT_TX BIT(1)
	#define EUD_INT_VBUS BIT(2)
	#define EUD_INT_CHGR BIT(3)
	#define EUD_INT_SAFE_MODE BIT(4)
	#define EUD_INT_ALL (EUD_INT_RX \| EUD_INT_TX \| \
	EUD_INT_VBUS \| EUD_INT_CHGR \| \
	EUD_INT_SAFE_MODE)

	#define EUD_NR 1
	#define EUD_CONSOLE NULL
	#define UART_ID 0x90
	#define MAX_FIFO_SIZE 14

	struct eud_chip {
	struct device *dev;
	int eud_irq;
	unsigned int extcon_id;
	unsigned int int_status;
	bool usb_attach;
	bool chgr_enable;
	void __iomem *eud_reg_base;
	struct extcon_dev *extcon;
	struct uart_port port;
	struct work_struct eud_work;
	};

	static const unsigned int eud_extcon_cable[] = {
	EXTCON_USB,
	EXTCON_CHG_USB_SDP,
	EXTCON_NONE,
	};

	/*
	* On the kernel command line specify eud.enable=1 to enable EUD.
	* EUD is disabled by default.
	*/
	static int enable;
	static struct platform_device *eud_private;

	static void enable_eud(struct platform_device *pdev)
	{
	struct eud_chip *priv = platform_get_drvdata(pdev);

	/* write into CSR to enable EUD */
	writel_relaxed(BIT(0), priv->eud_reg_base + EUD_REG_CSR_EUD_EN);
	/* Enable vbus, chgr & safe mode warning interrupts */
	writel_relaxed(EUD_INT_VBUS \| EUD_INT_CHGR \| EUD_INT_SAFE_MODE,
	priv->eud_reg_base + EUD_REG_INT1_EN_MASK);

	/* Ensure Register Writes Complete */
	wmb();

	dev_dbg(&pdev->dev, "%s: EUD Enabled!\n", __func__);
	}

	static void disable_eud(struct platform_device *pdev)
	{
	struct eud_chip *priv = platform_get_drvdata(pdev);

	/* write into CSR to disable EUD */
	writel_relaxed(0, priv->eud_reg_base + EUD_REG_CSR_EUD_EN);
	dev_dbg(&pdev->dev, "%s: EUD Disabled!\n", __func__);
	}

	static int param_eud_set(const char val, const struct kernel_param kp)
	{
	int enable = 0;

	if (sscanf(val, "%du", &enable) != 1)
	return -EINVAL;

	if (enable != EUD_ENABLE_CMD && enable != EUD_DISABLE_CMD)
	return -EINVAL;

	if (enable == EUD_ENABLE_CMD) {
	pr_debug("%s: Enbling EUD\n", __func__);
	enable_eud(eud_private);
	} else if (enable == EUD_DISABLE_CMD) {
	pr_debug("%s: Disabling EUD\n", __func__);
	disable_eud(eud_private);
	}

	((uint )kp->arg) = enable;
	return 0;
	}

	static const struct kernel_param_ops eud_param_ops = {
	.set = param_eud_set,
	.get = param_get_int,
	};

	module_param_cb(enable, &eud_param_ops, &enable, 0644);

	static void eud_event_notifier(struct work_struct *eud_work)
	{
	struct eud_chip *chip = container_of(eud_work, struct eud_chip,
	eud_work);

	if (chip->int_status == EUD_INT_VBUS)
	extcon_set_state_sync(chip->extcon, chip->extcon_id,
	chip->usb_attach);
	else if (chip->int_status == EUD_INT_CHGR)
	extcon_set_state_sync(chip->extcon, chip->extcon_id,
	chip->chgr_enable);
	}

	static void usb_attach_detach(struct eud_chip *chip)
	{
	u32 reg;

	chip->extcon_id = EXTCON_USB;
	/* read ctl_out_1[4] to find USB attach or detach event */
	reg = readl_relaxed(chip->eud_reg_base + EUD_REG_CTL_OUT_1);
	if (reg & BIT(4))
	chip->usb_attach = true;
	else
	chip->usb_attach = false;

	schedule_work(&chip->eud_work);

	/* set and clear vbus_int_clr[0] to clear interrupt */
	writel_relaxed(BIT(0), chip->eud_reg_base + EUD_REG_VBUS_INT_CLR);
	/* Ensure Register Writes Complete */
	wmb();
	writel_relaxed(0, chip->eud_reg_base + EUD_REG_VBUS_INT_CLR);
	}

	static void chgr_enable_disable(struct eud_chip *chip)
	{
	u32 reg;

	chip->extcon_id = EXTCON_CHG_USB_SDP;
	/* read ctl_out_1[6] to find charger enable or disable event */
	reg = readl_relaxed(chip->eud_reg_base + EUD_REG_CTL_OUT_1);
	if (reg & BIT(6))
	chip->chgr_enable = true;
	else
	chip->chgr_enable = false;

	schedule_work(&chip->eud_work);

	/* set and clear chgr_int_clr[0] to clear interrupt */
	writel_relaxed(BIT(0), chip->eud_reg_base + EUD_REG_CHGR_INT_CLR);
	/* Ensure Register Writes Complete */
	wmb();
	writel_relaxed(0, chip->eud_reg_base + EUD_REG_CHGR_INT_CLR);
	}

	static void pet_eud(struct eud_chip *chip)
	{
	u32 reg;

	/* read sw_attach_det[0] to find attach/detach event */
	reg = readl_relaxed(chip->eud_reg_base + EUD_REG_SW_ATTACH_DET);
	if (reg & BIT(0)) {
	/* Detach & Attach pet for EUD */
	writel_relaxed(0, chip->eud_reg_base + EUD_REG_SW_ATTACH_DET);
	/* Ensure Register Writes Complete */
	wmb();
	/* Delay to make sure detach pet is done before attach pet */
	udelay(100);
	writel_relaxed(BIT(0), chip->eud_reg_base +
	EUD_REG_SW_ATTACH_DET);
	/* Ensure Register Writes Complete */
	wmb();
	} else {
	/* Attach pet for EUD */
	writel_relaxed(BIT(0), chip->eud_reg_base +
	EUD_REG_SW_ATTACH_DET);
	/* Ensure Register Writes Complete */
	wmb();
	}
	}

	static unsigned int eud_tx_empty(struct uart_port *port)
	{
	u32 reg;

	/* read status register and cross check for Tx interrupt */
	reg = readl_relaxed(port->membase + EUD_REG_INT_STATUS_1);
	if (reg & EUD_INT_TX)
	return TIOCSER_TEMT;
	else
	return 0;
	}

	static void eud_stop_tx(struct uart_port *port)
	{
	/* Disable Tx interrupt */
	writel_relaxed(~EUD_INT_TX, port->membase + EUD_REG_INT_STATUS_1);
	/* Ensure Register Writes Complete */
	wmb();
	}

	static void eud_start_tx(struct uart_port *port)
	{
	/* Enable Tx interrupt */
	writel_relaxed(EUD_INT_TX, port->membase + EUD_REG_INT_STATUS_1);
	/* Ensure Register Writes Complete */
	wmb();
	}

	static void eud_stop_rx(struct uart_port *port)
	{
	/* Disable Rx interrupt */
	writel_relaxed(~EUD_INT_RX, port->membase + EUD_REG_INT_STATUS_1);
	/* Ensure Register Writes Complete */
	wmb();
	}

	static int eud_startup(struct uart_port *port)
	{
	/* Enable Rx interrupt */
	writel_relaxed(EUD_INT_RX, port->membase + EUD_REG_INT_STATUS_1);
	/* Ensure Register Writes Complete */
	wmb();
	return 0;
	}

	static void eud_shutdown(struct uart_port *port)
	{
	/* Disable both Tx & Rx interrupts */
	writel_relaxed(~EUD_INT_TX \| ~EUD_INT_RX,
	port->membase + EUD_REG_INT_STATUS_1);
	/* Ensure Register Writes Complete */
	wmb();
	}

	static const char eud_type(struct uart_port port)
	{
	return (port->type == PORT_EUD_UART) ? "EUD UART" : NULL;
	}

	static int eud_request_port(struct uart_port *port)
	{
	/* Nothing to request */
	return 0;
	}

	static void eud_release_port(struct uart_port *port)
	{
	/* Nothing to release */
	}

	static void eud_config_port(struct uart_port *port, int flags)
	{
	/* set port type, clear Tx and Rx interrupts */
	port->type = PORT_EUD_UART;
	writel_relaxed(~EUD_INT_TX \| ~EUD_INT_RX,
	port->membase + EUD_REG_INT_STATUS_1);
	/* Ensure Register Writes Complete */
	wmb();
	}

	static int eud_verify_port(struct uart_port *port,
	struct serial_struct *ser)
	{
	if (ser->type != PORT_UNKNOWN && ser->type != PORT_EUD_UART)
	return -EINVAL;
	return 0;
	}

	/* serial functions supported */
	static const struct uart_ops eud_uart_ops = {
	.tx_empty = eud_tx_empty,
	.stop_tx = eud_stop_tx,
	.start_tx = eud_start_tx,
	.stop_rx = eud_stop_rx,
	.startup = eud_startup,
	.shutdown = eud_shutdown,
	.type = eud_type,
	.release_port = eud_release_port,
	.request_port = eud_request_port,
	.config_port = eud_config_port,
	.verify_port = eud_verify_port,
	};

	static struct uart_driver eud_uart_driver = {
	.owner = THIS_MODULE,
	.driver_name = "msm-eud",
	.dev_name = "ttyEUD",
	.nr = EUD_NR,
	.cons = EUD_CONSOLE,
	};

	static void eud_uart_rx(struct eud_chip *chip)
	{
	struct uart_port *port = &chip->port;
	u32 reg;
	unsigned int len;
	unsigned char ch, flag;
	int i;

	reg = readl_relaxed(chip->eud_reg_base + EUD_REG_COM_RX_ID);
	if (reg != UART_ID) {
	dev_err(chip->dev, "Rx isn't for us!\n");
	return;
	}
	/* Read Rx Len & Data registers */
	spin_lock(&port->lock);
	len = readl_relaxed(chip->eud_reg_base + EUD_REG_COM_RX_LEN);
	for (i = 0; i < len; i++) {
	ch = readl_relaxed(chip->eud_reg_base + EUD_REG_COM_RX_DAT);
	flag = TTY_NORMAL;
	port->icount.rx++;

	if (uart_handle_sysrq_char(port, ch))
	continue;
	uart_insert_char(port, 0, 0, ch, flag);
	}

	spin_unlock(&port->lock);
	tty_flip_buffer_push(&port->state->port);
	}

	static void eud_uart_tx(struct eud_chip *chip)
	{
	struct uart_port *port = &chip->port;
	struct circ_buf *xmit = &port->state->xmit;
	unsigned int len;
	u32 reg;

	writel_relaxed(UART_ID, chip->eud_reg_base + EUD_REG_COM_TX_ID);
	reg = readl_relaxed(chip->eud_reg_base + EUD_REG_COM_TX_ID);
	if (reg != UART_ID) {
	dev_err(chip->dev, "Tx isn't for us!\n");
	return;
	}
	/* Write to Tx Len & Data registers */
	spin_lock(&port->lock);
	len = uart_circ_chars_pending(xmit);
	if (len > 0) {
	if (len > port->fifosize)
	len = port->fifosize;
	while (len--) {
	writel_relaxed(xmit->buf[xmit->tail],
	port->membase + EUD_REG_COM_TX_DAT);
	xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
	port->icount.tx++;
	}
	}
	spin_unlock(&port->lock);
	}

	static irqreturn_t handle_eud_irq(int irq, void *data)
	{
	struct eud_chip *chip = data;
	u32 reg;
	u32 int_mask_en1 = readl_relaxed(chip->eud_reg_base +
	EUD_REG_INT1_EN_MASK);

	/* read status register and find out which interrupt triggered */
	reg = readl_relaxed(chip->eud_reg_base + EUD_REG_INT_STATUS_1);
	if (reg & EUD_INT_RX) {
	dev_dbg(chip->dev, "EUD RX Interrupt!\n");
	eud_uart_rx(chip);
	} else if ((reg & EUD_INT_TX) & int_mask_en1) {
	dev_dbg(chip->dev, "EUD TX Interrupt!\n");
	eud_uart_tx(chip);
	} else if (reg & EUD_INT_VBUS) {
	dev_dbg(chip->dev, "EUD VBUS Interrupt!\n");
	chip->int_status = EUD_INT_VBUS;
	usb_attach_detach(chip);
	} else if (reg & EUD_INT_CHGR) {
	dev_dbg(chip->dev, "EUD CHGR Interrupt!\n");
	chip->int_status = EUD_INT_CHGR;
	chgr_enable_disable(chip);
	} else if (reg & EUD_INT_SAFE_MODE) {
	dev_dbg(chip->dev, "EUD SAFE MODE Interrupt!\n");
	pet_eud(chip);
	} else {
	dev_dbg(chip->dev, "Unknown/spurious EUD Interrupt!\n");
	return IRQ_NONE;
	}

	return IRQ_HANDLED;
	}

	static int msm_eud_probe(struct platform_device *pdev)
	{
	struct eud_chip *chip;
	struct uart_port *port;
	struct resource *res;
	int ret;

	chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
	if (!chip) {
	ret = -ENOMEM;
	return ret;
	}

	platform_set_drvdata(pdev, chip);

	chip->extcon = devm_extcon_dev_allocate(&pdev->dev, eud_extcon_cable);
	if (IS_ERR(chip->extcon)) {
	dev_err(chip->dev, "failed to allocate extcon device\n");
	return PTR_ERR(chip->extcon);
	}

	ret = devm_extcon_dev_register(&pdev->dev, chip->extcon);
	if (ret) {
	dev_err(chip->dev, "failed to register extcon device\n");
	return ret;
	}

	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "eud_base");
	if (!res) {
	dev_err(chip->dev, "%s: failed to get resource eud_base\n",
	__func__);
	ret = -ENOMEM;
	return ret;
	}

	chip->eud_reg_base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(chip->eud_reg_base))
	return PTR_ERR(chip->eud_reg_base);

	chip->eud_irq = platform_get_irq_byname(pdev, "eud_irq");

	ret = devm_request_irq(&pdev->dev, chip->eud_irq, handle_eud_irq,
	IRQF_TRIGGER_HIGH, "eud_irq", chip);
	if (ret) {
	dev_err(chip->dev, "request failed for eud irq\n");
	return ret;
	}

	device_init_wakeup(&pdev->dev, true);
	enable_irq_wake(chip->eud_irq);

	INIT_WORK(&chip->eud_work, eud_event_notifier);

	port = &chip->port;
	port->line = pdev->id;
	port->type = PORT_EUD_UART;
	port->dev = chip->dev;
	port->fifosize = MAX_FIFO_SIZE;
	port->iotype = SERIAL_IO_MEM;
	port->flags = UPF_BOOT_AUTOCONF;
	port->membase = chip->eud_reg_base;
	port->irq = chip->eud_irq;
	port->ops = &eud_uart_ops;

	ret = uart_add_one_port(&eud_uart_driver, port);
	if (!ret) {
	dev_err(chip->dev, "failed to add uart port!\n");
	return ret;
	}

	eud_private = pdev;

	/* Enable EUD */
	if (enable)
	enable_eud(pdev);

	return 0;
	}

	static int msm_eud_remove(struct platform_device *pdev)
	{
	struct eud_chip *chip = platform_get_drvdata(pdev);
	struct uart_port *port = &chip->port;

	uart_remove_one_port(&eud_uart_driver, port);
	device_init_wakeup(chip->dev, false);

	return 0;
	}

	static const struct of_device_id msm_eud_dt_match[] = {
	{.compatible = "qcom,msm-eud"},
	{},
	};
	MODULE_DEVICE_TABLE(of, msm_eud_dt_match);

	static struct platform_driver msm_eud_driver = {
	.probe = msm_eud_probe,
	.remove = msm_eud_remove,
	.driver = {
	.name = "msm-eud",
	.owner = THIS_MODULE,
	.of_match_table = msm_eud_dt_match,
	},
	};

	static int __init msm_eud_init(void)
	{
	int ret;

	ret = uart_register_driver(&eud_uart_driver);
	if (ret) {
	pr_err("%s: Failed to register EUD UART driver\n",
	__func__);
	return ret;
	}

	ret = platform_driver_register(&msm_eud_driver);
	if (ret) {
	pr_err("%s: Failed to register EUD driver\n",
	__func__);
	uart_unregister_driver(&eud_uart_driver);
	return ret;
	}

	return 0;
	}
	module_init(msm_eud_init);

	static void __exit msm_eud_exit(void)
	{
	platform_driver_unregister(&msm_eud_driver);
	uart_unregister_driver(&eud_uart_driver);
	}
	module_exit(msm_eud_exit);

	MODULE_DESCRIPTION("QTI EUD driver");
	MODULE_LICENSE("GPL v2");