drivers/misc/qfp_fuse.c - kernel/msm - Gitiles

 /* Copyright (c) 2011, Code Aurora Forum. 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.
  */

 #define pr_fmt(fmt) "%s: " fmt, __func__

 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/fs.h>
 #include <linux/slab.h>
 #include <linux/miscdevice.h>
 #include <linux/delay.h>
 #include <linux/qfp_fuse.h>
 #include <linux/io.h>
 #include <linux/uaccess.h>
 #include <linux/regulator/consumer.h>
 #include <linux/platform_device.h>
 #include <linux/mutex.h>

 /*
  * Time QFPROM requires to reliably burn a fuse.
  */
 #define QFPROM_BLOW_TIMEOUT_US      10
 #define QFPROM_BLOW_TIMER_OFFSET    0x2038
 /*
  * Denotes number of cycles required to blow the fuse.
  */
 #define QFPROM_BLOW_TIMER_VALUE     (QFPROM_BLOW_TIMEOUT_US * 83)

 #define QFPROM_BLOW_STATUS_OFFSET   0x204C
 #define QFPROM_BLOW_STATUS_BUSY     0x01
 #define QFPROM_BLOW_STATUS_ERROR    0x02

 #define QFP_FUSE_READY              0x01
 #define QFP_FUSE_OFF                0x00

 struct qfp_priv_t {
 	uint32_t base;
 	uint32_t end;
 	struct mutex lock;
 	struct regulator *fuse_vdd;
 	u8 state;
 };

 /* We need only one instance of this for the driver */
 static struct qfp_priv_t *qfp_priv;


 static int qfp_fuse_open(struct inode *inode, struct file *filp)
 {
 	if (qfp_priv == NULL)
 		return -ENODEV;

 	filp->private_data = qfp_priv;

 	return 0;
 }

 static int qfp_fuse_release(struct inode *inode, struct file *filp)
 {

 	filp->private_data = NULL;

 	return 0;
 }

 static inline int qfp_fuse_wait_for_fuse_blow(u32 *status)
 {
 	u32 timeout = QFPROM_BLOW_TIMEOUT_US;
 	/* wait for 400us before checking for the first time */
 	udelay(400);
 	do {
 		*status = readl_relaxed(
 			qfp_priv->base + QFPROM_BLOW_STATUS_OFFSET);

 		if (!(*status & QFPROM_BLOW_STATUS_BUSY))
 			return 0;

 		timeout--;
 		udelay(1);
 	} while (timeout);
 	pr_err("Timeout waiting for FUSE blow, status = %x\n", *status);
 	return -ETIMEDOUT;
 }

 static inline int qfp_fuse_enable_regulator(void)
 {
 	int err;
 	err = regulator_enable(qfp_priv->fuse_vdd);
 	if (err != 0)
 		pr_err("Error (%d) enabling regulator\n", err);
 	return err;
 }

 static inline int qfp_fuse_disable_regulator(void)
 {
 	int err;
 	err = regulator_disable(qfp_priv->fuse_vdd);
 	if (err != 0)
 		pr_err("Error (%d) disabling regulator\n", err);
 	return err;
 }

 static int qfp_fuse_write_word(u32 *addr, u32 data)
 {
 	u32 blow_status = 0;
 	u32 read_data;
 	int err;

 	/* Set QFPROM  blow timer register */
 	writel_relaxed(QFPROM_BLOW_TIMER_VALUE,
 			qfp_priv->base + QFPROM_BLOW_TIMER_OFFSET);
 	mb();

 	/* Enable LVS0 regulator */
 	err = qfp_fuse_enable_regulator();
 	if (err != 0)
 		return err;

 	/*
 	 * Wait for about 1ms. However msleep(1) can sleep for
 	 * up to 20ms as per Documentation/timers/timers-howto.txt.
 	 * Time is not a constraint here.
 	 */

 	msleep(20);

 	/* Write data */
 	__raw_writel(data, addr);
 	mb();

 	/* blow_status = QFPROM_BLOW_STATUS_BUSY; */
 	err = qfp_fuse_wait_for_fuse_blow(&blow_status);
 	if (err) {
 		qfp_fuse_disable_regulator();
 		return err;
 	}

 	/* Check error status */
 	if (blow_status & QFPROM_BLOW_STATUS_ERROR) {
 		pr_err("Fuse blow status error: %d\n", blow_status);
 		qfp_fuse_disable_regulator();
 		return -EFAULT;
 	}

 	/* Disable regulator */
 	qfp_fuse_disable_regulator();
 	/*
 	 * Wait for about 1ms. However msleep(1) can sleep for
 	 * up to 20ms as per Documentation/timers/timers-howto.txt.
 	 * Time is not a constraint here.
 	 */
 	msleep(20);

 	/* Verify written data */
 	read_data = readl_relaxed(addr);
 	if (read_data != data) {
 		pr_err("Error: read/write data mismatch\n");
 		pr_err("Address = %p written data = %x read data = %x\n",
 			addr, data, read_data);
 		return -EFAULT;
 	}

 	return 0;
 }

 static long
 qfp_fuse_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
 	int err = 0;
 	struct qfp_fuse_req req;
 	u32 *buf = NULL;
 	int i;

 	/* Verify user arguments. */
 	if (_IOC_TYPE(cmd) != QFP_FUSE_IOC_MAGIC)
 		return -ENOTTY;

 	switch (cmd) {
 	case QFP_FUSE_IOC_READ:
 		if (arg == 0) {
 			pr_err("user space arg not supplied\n");
 			err = -EFAULT;
 			break;
 		}

 		if (copy_from_user(&req, (void __user *)arg, sizeof(req))) {
 			pr_err("Error copying req from user space\n");
 			err = -EFAULT;
 			break;
 		}

 		/* Check for limits */
 		if (!req.size) {
 			pr_err("Request size zero.\n");
 			err = -EFAULT;
 			break;
 		}

 		if (qfp_priv->base + req.offset + (req.size - 1) * 4 >
 				qfp_priv->end) {
 			pr_err("Req size exceeds QFPROM addr space\n");
 			err = -EFAULT;
 			break;
 		}

 		/* Allocate memory for buffer */
 		buf = kzalloc(req.size * 4, GFP_KERNEL);
 		if (buf == NULL) {
 			pr_alert("No memory for data\n");
 			err = -ENOMEM;
 			break;
 		}

 		if (mutex_lock_interruptible(&qfp_priv->lock)) {
 			err = -ERESTARTSYS;
 			break;
 		}

 		/* Read data */
 		for (i = 0; i < req.size; i++)
 			buf[i] = readl_relaxed(
 				((u32 *) (qfp_priv->base + req.offset)) + i);

 		if (copy_to_user((void __user *)req.data, buf, 4*(req.size))) {
 			pr_err("Error copying to user space\n");
 			err = -EFAULT;
 		}

 		mutex_unlock(&qfp_priv->lock);
 		break;

 	case QFP_FUSE_IOC_WRITE:
 		if (arg == 0) {
 			pr_err("user space arg not supplied\n");
 			err = -EFAULT;
 			break;
 		}

 		if (copy_from_user(&req, (void __user *)arg, sizeof(req))) {
 			pr_err("Error copying req from user space\n");
 			err = -EFAULT;
 			break;
 		}
 		/* Check for limits */
 		if (!req.size) {
 			pr_err("Request size zero.\n");
 			err = -EFAULT;
 			break;
 		}
 		if (qfp_priv->base + req.offset + (req.size - 1) * 4 >
 				qfp_priv->end) {
 			pr_err("Req size exceeds QFPROM space\n");
 			err = -EFAULT;
 			break;
 		}

 		/* Allocate memory for buffer */
 		buf = kzalloc(4 * (req.size), GFP_KERNEL);
 		if (buf == NULL) {
 			pr_alert("No memory for data\n");
 			err = -ENOMEM;
 			break;
 		}

 		/* Copy user data to local buffer */
 		if (copy_from_user(buf, (void __user *)req.data,
 				4 * (req.size))) {
 			pr_err("Error copying data from user space\n");
 			err = -EFAULT;
 			break;
 		}

 		if (mutex_lock_interruptible(&qfp_priv->lock)) {
 			err = -ERESTARTSYS;
 			break;
 		}

 		/* Write data word at a time */
 		for (i = 0; i < req.size && !err; i++) {
 			err = qfp_fuse_write_word(((u32 *) (
 				qfp_priv->base + req.offset) + i), buf[i]);
 		}

 		mutex_unlock(&qfp_priv->lock);
 		break;
 	default:
 		pr_err("Invalid ioctl command.\n");
 		return -ENOTTY;
 	}
 	kfree(buf);
 	return err;
 }

 static const struct file_operations qfp_fuse_fops = {
 	.owner = THIS_MODULE,
 	.unlocked_ioctl = qfp_fuse_ioctl,
 	.open = qfp_fuse_open,
 	.release = qfp_fuse_release
 };

 static struct miscdevice qfp_fuse_dev = {
 	.minor = MISC_DYNAMIC_MINOR,
 	.name = "qfpfuse",
 	.fops = &qfp_fuse_fops
 };


 static int qfp_fuse_probe(struct platform_device *pdev)
 {
 	int ret = 0;
 	struct resource *res;
 	const char *regulator_name = pdev->dev.platform_data;


 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!res)
 		return -ENODEV;

 	if (!regulator_name)
 		return -EINVAL;

 	/* Initialize */
 	qfp_priv = kzalloc(sizeof(struct qfp_priv_t), GFP_KERNEL);

 	if (qfp_priv == NULL) {
 		pr_alert("Not enough memory to initialize device\n");
 		return -ENOMEM;
 	}

 	/* The driver is passed ioremapped address */
 	qfp_priv->base = res->start;
 	qfp_priv->end = res->end;

 	/* Get regulator for QFPROM writes */
 	qfp_priv->fuse_vdd = regulator_get(NULL, regulator_name);
 	if (IS_ERR(qfp_priv->fuse_vdd)) {
 		ret = PTR_ERR(qfp_priv->fuse_vdd);
 		pr_err("Err (%d) getting %s\n", ret, regulator_name);
 		qfp_priv->fuse_vdd = NULL;
 		goto err;
 	}

 	mutex_init(&qfp_priv->lock);

 	ret = misc_register(&qfp_fuse_dev);
 	if (ret < 0)
 		goto err;

 	pr_info("Fuse driver base:%x end:%x\n", qfp_priv->base, qfp_priv->end);
 	return 0;

 err:
 	if (qfp_priv->fuse_vdd)
 		regulator_put(qfp_priv->fuse_vdd);

 	kfree(qfp_priv);
 	qfp_priv = NULL;

 	return ret;

 }

 static int __devexit qfp_fuse_remove(struct platform_device *plat)
 {
 	if (qfp_priv && qfp_priv->fuse_vdd)
 		regulator_put(qfp_priv->fuse_vdd);

 	kfree(qfp_priv);
 	qfp_priv = NULL;

 	misc_deregister(&qfp_fuse_dev);
 	pr_info("Removing Fuse driver\n");
 	return 0;
 }

 static struct platform_driver qfp_fuse_driver = {
 	.probe = qfp_fuse_probe,
 	.remove = qfp_fuse_remove,
 	.driver = {
 		.name = "qfp_fuse_driver",
 		.owner = THIS_MODULE,
 	},
 };

 static int __init qfp_fuse_init(void)
 {
 	return platform_driver_register(&qfp_fuse_driver);
 }

 static void __exit qfp_fuse_exit(void)
 {
 	platform_driver_unregister(&qfp_fuse_driver);
 }

 MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR("Rohit Vaswani <rvaswani@codeaurora.org>");
 MODULE_DESCRIPTION("Driver to read/write to QFPROM fuses.");
 MODULE_VERSION("1.01");

 module_init(qfp_fuse_init);
 module_exit(qfp_fuse_exit);
	/* Copyright (c) 2011, Code Aurora Forum. 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.
	*/

	#define pr_fmt(fmt) "%s: " fmt, __func__

	#include <linux/init.h>
	#include <linux/module.h>
	#include <linux/fs.h>
	#include <linux/slab.h>
	#include <linux/miscdevice.h>
	#include <linux/delay.h>
	#include <linux/qfp_fuse.h>
	#include <linux/io.h>
	#include <linux/uaccess.h>
	#include <linux/regulator/consumer.h>
	#include <linux/platform_device.h>
	#include <linux/mutex.h>

	/*
	* Time QFPROM requires to reliably burn a fuse.
	*/
	#define QFPROM_BLOW_TIMEOUT_US 10
	#define QFPROM_BLOW_TIMER_OFFSET 0x2038
	/*
	* Denotes number of cycles required to blow the fuse.
	*/
	#define QFPROM_BLOW_TIMER_VALUE (QFPROM_BLOW_TIMEOUT_US * 83)

	#define QFPROM_BLOW_STATUS_OFFSET 0x204C
	#define QFPROM_BLOW_STATUS_BUSY 0x01
	#define QFPROM_BLOW_STATUS_ERROR 0x02

	#define QFP_FUSE_READY 0x01
	#define QFP_FUSE_OFF 0x00

	struct qfp_priv_t {
	uint32_t base;
	uint32_t end;
	struct mutex lock;
	struct regulator *fuse_vdd;
	u8 state;
	};

	/* We need only one instance of this for the driver */
	static struct qfp_priv_t *qfp_priv;


	static int qfp_fuse_open(struct inode inode, struct file filp)
	{
	if (qfp_priv == NULL)
	return -ENODEV;

	filp->private_data = qfp_priv;

	return 0;
	}

	static int qfp_fuse_release(struct inode inode, struct file filp)
	{

	filp->private_data = NULL;

	return 0;
	}

	static inline int qfp_fuse_wait_for_fuse_blow(u32 *status)
	{
	u32 timeout = QFPROM_BLOW_TIMEOUT_US;
	/* wait for 400us before checking for the first time */
	udelay(400);
	do {
	*status = readl_relaxed(
	qfp_priv->base + QFPROM_BLOW_STATUS_OFFSET);

	if (!(*status & QFPROM_BLOW_STATUS_BUSY))
	return 0;

	timeout--;
	udelay(1);
	} while (timeout);
	pr_err("Timeout waiting for FUSE blow, status = %x\n", *status);
	return -ETIMEDOUT;
	}

	static inline int qfp_fuse_enable_regulator(void)
	{
	int err;
	err = regulator_enable(qfp_priv->fuse_vdd);
	if (err != 0)
	pr_err("Error (%d) enabling regulator\n", err);
	return err;
	}

	static inline int qfp_fuse_disable_regulator(void)
	{
	int err;
	err = regulator_disable(qfp_priv->fuse_vdd);
	if (err != 0)
	pr_err("Error (%d) disabling regulator\n", err);
	return err;
	}

	static int qfp_fuse_write_word(u32 *addr, u32 data)
	{
	u32 blow_status = 0;
	u32 read_data;
	int err;

	/* Set QFPROM blow timer register */
	writel_relaxed(QFPROM_BLOW_TIMER_VALUE,
	qfp_priv->base + QFPROM_BLOW_TIMER_OFFSET);
	mb();

	/* Enable LVS0 regulator */
	err = qfp_fuse_enable_regulator();
	if (err != 0)
	return err;

	/*
	* Wait for about 1ms. However msleep(1) can sleep for
	* up to 20ms as per Documentation/timers/timers-howto.txt.
	* Time is not a constraint here.
	*/

	msleep(20);

	/* Write data */
	__raw_writel(data, addr);
	mb();

	/* blow_status = QFPROM_BLOW_STATUS_BUSY; */
	err = qfp_fuse_wait_for_fuse_blow(&blow_status);
	if (err) {
	qfp_fuse_disable_regulator();
	return err;
	}

	/* Check error status */
	if (blow_status & QFPROM_BLOW_STATUS_ERROR) {
	pr_err("Fuse blow status error: %d\n", blow_status);
	qfp_fuse_disable_regulator();
	return -EFAULT;
	}

	/* Disable regulator */
	qfp_fuse_disable_regulator();
	/*
	* Wait for about 1ms. However msleep(1) can sleep for
	* up to 20ms as per Documentation/timers/timers-howto.txt.
	* Time is not a constraint here.
	*/
	msleep(20);

	/* Verify written data */
	read_data = readl_relaxed(addr);
	if (read_data != data) {
	pr_err("Error: read/write data mismatch\n");
	pr_err("Address = %p written data = %x read data = %x\n",
	addr, data, read_data);
	return -EFAULT;
	}

	return 0;
	}

	static long
	qfp_fuse_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
	{
	int err = 0;
	struct qfp_fuse_req req;
	u32 *buf = NULL;
	int i;

	/* Verify user arguments. */
	if (_IOC_TYPE(cmd) != QFP_FUSE_IOC_MAGIC)
	return -ENOTTY;

	switch (cmd) {
	case QFP_FUSE_IOC_READ:
	if (arg == 0) {
	pr_err("user space arg not supplied\n");
	err = -EFAULT;
	break;
	}

	if (copy_from_user(&req, (void __user *)arg, sizeof(req))) {
	pr_err("Error copying req from user space\n");
	err = -EFAULT;
	break;
	}

	/* Check for limits */
	if (!req.size) {
	pr_err("Request size zero.\n");
	err = -EFAULT;
	break;
	}

	if (qfp_priv->base + req.offset + (req.size - 1) * 4 >
	qfp_priv->end) {
	pr_err("Req size exceeds QFPROM addr space\n");
	err = -EFAULT;
	break;
	}

	/* Allocate memory for buffer */
	buf = kzalloc(req.size * 4, GFP_KERNEL);
	if (buf == NULL) {
	pr_alert("No memory for data\n");
	err = -ENOMEM;
	break;
	}

	if (mutex_lock_interruptible(&qfp_priv->lock)) {
	err = -ERESTARTSYS;
	break;
	}

	/* Read data */
	for (i = 0; i < req.size; i++)
	buf[i] = readl_relaxed(
	((u32 *) (qfp_priv->base + req.offset)) + i);

	if (copy_to_user((void __user )req.data, buf, 4(req.size))) {
	pr_err("Error copying to user space\n");
	err = -EFAULT;
	}

	mutex_unlock(&qfp_priv->lock);
	break;

	case QFP_FUSE_IOC_WRITE:
	if (arg == 0) {
	pr_err("user space arg not supplied\n");
	err = -EFAULT;
	break;
	}

	if (copy_from_user(&req, (void __user *)arg, sizeof(req))) {
	pr_err("Error copying req from user space\n");
	err = -EFAULT;
	break;
	}
	/* Check for limits */
	if (!req.size) {
	pr_err("Request size zero.\n");
	err = -EFAULT;
	break;
	}
	if (qfp_priv->base + req.offset + (req.size - 1) * 4 >
	qfp_priv->end) {
	pr_err("Req size exceeds QFPROM space\n");
	err = -EFAULT;
	break;
	}

	/* Allocate memory for buffer */
	buf = kzalloc(4 * (req.size), GFP_KERNEL);
	if (buf == NULL) {
	pr_alert("No memory for data\n");
	err = -ENOMEM;
	break;
	}

	/* Copy user data to local buffer */
	if (copy_from_user(buf, (void __user *)req.data,
	4 * (req.size))) {
	pr_err("Error copying data from user space\n");
	err = -EFAULT;
	break;
	}

	if (mutex_lock_interruptible(&qfp_priv->lock)) {
	err = -ERESTARTSYS;
	break;
	}

	/* Write data word at a time */
	for (i = 0; i < req.size && !err; i++) {
	err = qfp_fuse_write_word(((u32 *) (
	qfp_priv->base + req.offset) + i), buf[i]);
	}

	mutex_unlock(&qfp_priv->lock);
	break;
	default:
	pr_err("Invalid ioctl command.\n");
	return -ENOTTY;
	}
	kfree(buf);
	return err;
	}

	static const struct file_operations qfp_fuse_fops = {
	.owner = THIS_MODULE,
	.unlocked_ioctl = qfp_fuse_ioctl,
	.open = qfp_fuse_open,
	.release = qfp_fuse_release
	};

	static struct miscdevice qfp_fuse_dev = {
	.minor = MISC_DYNAMIC_MINOR,
	.name = "qfpfuse",
	.fops = &qfp_fuse_fops
	};


	static int qfp_fuse_probe(struct platform_device *pdev)
	{
	int ret = 0;
	struct resource *res;
	const char *regulator_name = pdev->dev.platform_data;


	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res)
	return -ENODEV;

	if (!regulator_name)
	return -EINVAL;

	/* Initialize */
	qfp_priv = kzalloc(sizeof(struct qfp_priv_t), GFP_KERNEL);

	if (qfp_priv == NULL) {
	pr_alert("Not enough memory to initialize device\n");
	return -ENOMEM;
	}

	/* The driver is passed ioremapped address */
	qfp_priv->base = res->start;
	qfp_priv->end = res->end;

	/* Get regulator for QFPROM writes */
	qfp_priv->fuse_vdd = regulator_get(NULL, regulator_name);
	if (IS_ERR(qfp_priv->fuse_vdd)) {
	ret = PTR_ERR(qfp_priv->fuse_vdd);
	pr_err("Err (%d) getting %s\n", ret, regulator_name);
	qfp_priv->fuse_vdd = NULL;
	goto err;
	}

	mutex_init(&qfp_priv->lock);

	ret = misc_register(&qfp_fuse_dev);
	if (ret < 0)
	goto err;

	pr_info("Fuse driver base:%x end:%x\n", qfp_priv->base, qfp_priv->end);
	return 0;

	err:
	if (qfp_priv->fuse_vdd)
	regulator_put(qfp_priv->fuse_vdd);

	kfree(qfp_priv);
	qfp_priv = NULL;

	return ret;

	}

	static int __devexit qfp_fuse_remove(struct platform_device *plat)
	{
	if (qfp_priv && qfp_priv->fuse_vdd)
	regulator_put(qfp_priv->fuse_vdd);

	kfree(qfp_priv);
	qfp_priv = NULL;

	misc_deregister(&qfp_fuse_dev);
	pr_info("Removing Fuse driver\n");
	return 0;
	}

	static struct platform_driver qfp_fuse_driver = {
	.probe = qfp_fuse_probe,
	.remove = qfp_fuse_remove,
	.driver = {
	.name = "qfp_fuse_driver",
	.owner = THIS_MODULE,
	},
	};

	static int __init qfp_fuse_init(void)
	{
	return platform_driver_register(&qfp_fuse_driver);
	}

	static void __exit qfp_fuse_exit(void)
	{
	platform_driver_unregister(&qfp_fuse_driver);
	}

	MODULE_LICENSE("GPL v2");
	MODULE_AUTHOR("Rohit Vaswani <rvaswani@codeaurora.org>");
	MODULE_DESCRIPTION("Driver to read/write to QFPROM fuses.");
	MODULE_VERSION("1.01");

	module_init(qfp_fuse_init);
	module_exit(qfp_fuse_exit);