316 lines
6.8 KiB
C
316 lines
6.8 KiB
C
/* Copyright (c) 2011-2014, The Linux Foundation. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 and
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* only version 2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#define pr_fmt(fmt) "%s: " fmt, __func__
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/fs.h>
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#include <linux/slab.h>
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#include <linux/miscdevice.h>
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#include <linux/delay.h>
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#include <linux/qfp_fuse.h>
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#include <linux/io.h>
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#include <linux/uaccess.h>
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#include <linux/regulator/consumer.h>
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#include <linux/platform_device.h>
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#include <linux/mutex.h>
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#include <linux/of.h>
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/*
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* Time QFPROM requires to reliably burn a fuse.
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*/
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#define QFPROM_BLOW_TIMEOUT_US 20
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#define QFPROM_BLOW_TIMER_OFFSET 0x2038
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/*
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* Denotes number of cycles required to blow the fuse.
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*/
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#define QFPROM_BLOW_TIMER_VALUE 0xF0
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#define QFPROM_BLOW_STATUS_OFFSET 0x204C
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#define QFPROM_BLOW_STATUS_BUSY 0x01
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#define QFPROM_BLOW_STATUS_ERROR 0x02
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#define QFP_FUSE_READY 0x01
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#define QFP_FUSE_OFF 0x00
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#define QFP_FUSE_BUF_SIZE 64
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#define UINT32_MAX (0xFFFFFFFFU)
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struct qfp_priv_t {
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void __iomem *base;
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uint32_t size;
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uint32_t blow_status_offset;
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uint32_t blow_timer;
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struct mutex lock;
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u8 state;
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};
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struct qfp_resource {
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resource_size_t start;
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resource_size_t size;
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uint32_t blow_status_offset;
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uint32_t blow_timer;
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};
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/* We need only one instance of this for the driver */
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static struct qfp_priv_t *qfp_priv;
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static inline bool is_usr_req_valid(const struct qfp_fuse_req *req)
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{
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uint32_t size = qfp_priv->size;
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uint32_t req_size;
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if (req->size >= (UINT32_MAX / sizeof(uint32_t)))
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return false;
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req_size = req->size * sizeof(uint32_t);
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if ((req_size == 0) || (req_size > size))
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return false;
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if (req->offset >= size)
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return false;
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if ((req->offset + req_size) > size)
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return false;
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return true;
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}
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static int qfp_fuse_open(struct inode *inode, struct file *filp)
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{
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if (qfp_priv == NULL)
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return -ENODEV;
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filp->private_data = qfp_priv;
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return 0;
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}
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static int qfp_fuse_release(struct inode *inode, struct file *filp)
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{
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filp->private_data = NULL;
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return 0;
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}
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static long
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qfp_fuse_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
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{
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int err = 0;
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struct qfp_fuse_req req;
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u32 fuse_buf[QFP_FUSE_BUF_SIZE];
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u32 *buf = fuse_buf;
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u32 *ptr = NULL;
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int i;
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/* Verify user arguments. */
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if (_IOC_TYPE(cmd) != QFP_FUSE_IOC_MAGIC)
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return -ENOTTY;
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switch (cmd) {
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case QFP_FUSE_IOC_READ:
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if (arg == 0) {
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pr_err("user space arg not supplied\n");
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err = -EFAULT;
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break;
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}
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if (copy_from_user(&req, (void __user *)arg, sizeof(req))) {
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pr_err("Error copying req from user space\n");
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err = -EFAULT;
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break;
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}
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/* Check for limits */
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if (is_usr_req_valid(&req) == false) {
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pr_err("Invalid request\n");
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err = -EINVAL;
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break;
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}
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if (req.size > QFP_FUSE_BUF_SIZE) {
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/* Allocate memory for buffer */
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ptr = kzalloc(req.size * 4, GFP_KERNEL);
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if (ptr == NULL) {
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pr_alert("No memory for data\n");
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err = -ENOMEM;
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break;
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}
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buf = ptr;
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}
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if (mutex_lock_interruptible(&qfp_priv->lock)) {
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err = -ERESTARTSYS;
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break;
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}
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/* Read data */
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for (i = 0; i < req.size; i++)
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buf[i] = readl_relaxed(
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((u32 *) (qfp_priv->base + req.offset)) + i);
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if (copy_to_user((void __user *)req.data, buf, 4*(req.size))) {
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pr_err("Error copying to user space\n");
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err = -EFAULT;
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}
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mutex_unlock(&qfp_priv->lock);
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break;
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case QFP_FUSE_IOC_WRITE:
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pr_err("Fuse-write is no longer supported.\n");
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return -EPERM;
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break;
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default:
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pr_err("Invalid ioctl command.\n");
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return -ENOTTY;
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}
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kfree(ptr);
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return err;
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}
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static const struct file_operations qfp_fuse_fops = {
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.owner = THIS_MODULE,
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.unlocked_ioctl = qfp_fuse_ioctl,
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.open = qfp_fuse_open,
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.release = qfp_fuse_release
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};
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static struct miscdevice qfp_fuse_dev = {
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.minor = MISC_DYNAMIC_MINOR,
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.name = "qfpfuse",
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.fops = &qfp_fuse_fops
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};
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static int qfp_get_resource(struct platform_device *pdev,
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struct qfp_resource *qfp_res)
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{
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struct resource *res;
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uint32_t blow_status_offset = QFPROM_BLOW_STATUS_OFFSET;
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uint32_t blow_timer = QFPROM_BLOW_TIMER_VALUE;
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!res)
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return -ENODEV;
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if (pdev->dev.of_node) {
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struct device_node *np = pdev->dev.of_node;
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if (of_property_read_u32(np, "qcom,blow-status-offset",
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&blow_status_offset) == 0) {
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if ((res->start + blow_status_offset) > res->end) {
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pr_err("Invalid blow-status-offset\n");
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return -EINVAL;
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}
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}
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of_property_read_u32(np, "qcom,blow-timer", &blow_timer);
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}
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qfp_res->start = res->start;
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qfp_res->size = resource_size(res);
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qfp_res->blow_status_offset = blow_status_offset;
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qfp_res->blow_timer = blow_timer;
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return 0;
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}
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static int qfp_fuse_probe(struct platform_device *pdev)
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{
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int ret = 0;
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struct qfp_resource res;
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ret = qfp_get_resource(pdev, &res);
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if (ret)
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return ret;
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/* Initialize */
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qfp_priv = kzalloc(sizeof(struct qfp_priv_t), GFP_KERNEL);
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if (qfp_priv == NULL) {
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pr_alert("Not enough memory to initialize device\n");
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return -ENOMEM;
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}
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qfp_priv->base = ioremap(res.start, res.size);
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if (!qfp_priv->base) {
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pr_warn("ioremap failed\n");
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goto err;
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}
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qfp_priv->size = res.size;
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qfp_priv->blow_status_offset = res.blow_status_offset;
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qfp_priv->blow_timer = res.blow_timer;
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mutex_init(&qfp_priv->lock);
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ret = misc_register(&qfp_fuse_dev);
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if (ret < 0)
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goto err;
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pr_info("Fuse driver base:%p end:%p\n", qfp_priv->base,
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qfp_priv->base + qfp_priv->size);
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return 0;
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err:
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kfree(qfp_priv);
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qfp_priv = NULL;
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return ret;
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}
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static int qfp_fuse_remove(struct platform_device *plat)
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{
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iounmap((void __iomem *)qfp_priv->base);
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kfree(qfp_priv);
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qfp_priv = NULL;
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misc_deregister(&qfp_fuse_dev);
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pr_info("Removing Fuse driver\n");
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return 0;
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}
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static struct of_device_id __attribute__ ((unused)) qfp_fuse_of_match[] = {
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{ .compatible = "qcom,qfp-fuse", },
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{}
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};
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static struct platform_driver qfp_fuse_driver = {
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.probe = qfp_fuse_probe,
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.remove = qfp_fuse_remove,
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.driver = {
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.name = "qfp_fuse_driver",
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.owner = THIS_MODULE,
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.of_match_table = of_match_ptr(qfp_fuse_of_match),
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},
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};
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static int __init qfp_fuse_init(void)
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{
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return platform_driver_register(&qfp_fuse_driver);
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}
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static void __exit qfp_fuse_exit(void)
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{
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platform_driver_unregister(&qfp_fuse_driver);
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}
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MODULE_LICENSE("GPL v2");
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MODULE_AUTHOR("Rohit Vaswani <rvaswani@codeaurora.org>");
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MODULE_DESCRIPTION("Driver to read/write to QFPROM fuses.");
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MODULE_VERSION("1.01");
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module_init(qfp_fuse_init);
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module_exit(qfp_fuse_exit);
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