diff options
Diffstat (limited to 'drivers/char/fsl_otp.c')
| -rw-r--r-- | drivers/char/fsl_otp.c | 240 |
1 files changed, 240 insertions, 0 deletions
diff --git a/drivers/char/fsl_otp.c b/drivers/char/fsl_otp.c new file mode 100644 index 000000000000..fbc52b870d3a --- /dev/null +++ b/drivers/char/fsl_otp.c @@ -0,0 +1,240 @@ +/* + * Freescale On-Chip OTP driver + * + * Copyright (C) 2010 Freescale Semiconductor, Inc. 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 as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ +#include <linux/kobject.h> +#include <linux/string.h> +#include <linux/sysfs.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/delay.h> +#include <linux/fcntl.h> +#include <linux/mutex.h> +#include <linux/clk.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/slab.h> +#include <linux/platform_device.h> + +#include "fsl_otp.h" + +static DEFINE_MUTEX(otp_mutex); +static struct kobject *otp_kobj; +static struct attribute **attrs; +static struct kobj_attribute *kattr; +static struct attribute_group attr_group; +static struct fsl_otp_data *otp_data; + +static inline unsigned int get_reg_index(struct kobj_attribute *tmp) +{ + return tmp - kattr; +} + +static int otp_wait_busy(u32 flags) +{ + int count; + u32 c; + + for (count = 10000; count >= 0; count--) { + c = __raw_readl(REGS_OCOTP_BASE + HW_OCOTP_CTRL); + if (!(c & (BM_OCOTP_CTRL_BUSY | BM_OCOTP_CTRL_ERROR | flags))) + break; + cpu_relax(); + } + if (count < 0) + return -ETIMEDOUT; + return 0; +} + +static ssize_t otp_show(struct kobject *kobj, struct kobj_attribute *attr, + char *buf) +{ + unsigned int index = get_reg_index(attr); + u32 value = 0; + + /* sanity check */ + if (index >= otp_data->fuse_num) + return 0; + + mutex_lock(&otp_mutex); + + if (otp_read_prepare()) { + mutex_unlock(&otp_mutex); + return 0; + } + value = __raw_readl(REGS_OCOTP_BASE + HW_OCOTP_CUSTn(index)); + otp_read_post(); + + mutex_unlock(&otp_mutex); + return sprintf(buf, "0x%x\n", value); +} + +static int otp_write_bits(int addr, u32 data, u32 magic) +{ + u32 c; /* for control register */ + + /* init the control register */ + c = __raw_readl(REGS_OCOTP_BASE + HW_OCOTP_CTRL); + c &= ~BM_OCOTP_CTRL_ADDR; + c |= BF(addr, OCOTP_CTRL_ADDR); + c |= BF(magic, OCOTP_CTRL_WR_UNLOCK); + __raw_writel(c, REGS_OCOTP_BASE + HW_OCOTP_CTRL); + + /* init the data register */ + __raw_writel(data, REGS_OCOTP_BASE + HW_OCOTP_DATA); + otp_wait_busy(0); + + mdelay(2); /* Write Postamble */ + return 0; +} + +static ssize_t otp_store(struct kobject *kobj, struct kobj_attribute *attr, + const char *buf, size_t count) +{ + unsigned int index = get_reg_index(attr); + int value; + + /* sanity check */ + if (index >= otp_data->fuse_num) + return 0; + + sscanf(buf, "0x%x", &value); + + mutex_lock(&otp_mutex); + if (otp_write_prepare(otp_data)) { + mutex_unlock(&otp_mutex); + return 0; + } + otp_write_bits(index, value, 0x3e77); + otp_write_post(); + mutex_unlock(&otp_mutex); + return count; +} + +static void free_otp_attr(void) +{ + kfree(attrs); + attrs = NULL; + + kfree(kattr); + kattr = NULL; +} + +static int __init alloc_otp_attr(struct fsl_otp_data *pdata) +{ + int i; + + otp_data = pdata; /* get private data */ + + /* The last one is NULL, which is used to detect the end */ + attrs = kzalloc((otp_data->fuse_num + 1) * sizeof(attrs[0]), + GFP_KERNEL); + kattr = kzalloc(otp_data->fuse_num * sizeof(struct kobj_attribute), + GFP_KERNEL); + + if (!attrs || !kattr) + goto error_out; + + for (i = 0; i < otp_data->fuse_num; i++) { + kattr[i].attr.name = pdata->fuse_name[i]; + kattr[i].attr.mode = 0600; + kattr[i].show = otp_show; + kattr[i].store = otp_store; + + attrs[i] = &kattr[i].attr; + } + memset(&attr_group, 0, sizeof(attr_group)); + attr_group.attrs = attrs; + return 0; + +error_out: + free_otp_attr(); + return -ENOMEM; +} + +static int __devinit fsl_otp_probe(struct platform_device *pdev) +{ + int retval; + struct fsl_otp_data *pdata; + + pdata = pdev->dev.platform_data; + if (pdata == NULL) + return -ENODEV; + + retval = alloc_otp_attr(pdata); + if (retval) + return retval; + + retval = map_ocotp_addr(pdev); + if (retval) + goto error; + + otp_kobj = kobject_create_and_add("fsl_otp", NULL); + if (!otp_kobj) { + retval = -ENOMEM; + goto error; + } + + retval = sysfs_create_group(otp_kobj, &attr_group); + if (retval) + goto error; + + mutex_init(&otp_mutex); + return 0; +error: + kobject_put(otp_kobj); + otp_kobj = NULL; + free_otp_attr(); + unmap_ocotp_addr(); + return retval; +} + +static int otp_remove(struct platform_device *pdev) +{ + kobject_put(otp_kobj); + otp_kobj = NULL; + + free_otp_attr(); + unmap_ocotp_addr(); + return 0; +} + +static struct platform_driver ocotp_driver = { + .probe = fsl_otp_probe, + .remove = otp_remove, + .driver = { + .name = "ocotp", + .owner = THIS_MODULE, + }, +}; + +static int __init fsl_otp_init(void) +{ + return platform_driver_register(&ocotp_driver); +} + +static void __exit fsl_otp_exit(void) +{ + platform_driver_unregister(&ocotp_driver); +} +module_init(fsl_otp_init); +module_exit(fsl_otp_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Huang Shijie <b32955@freescale.com>"); +MODULE_DESCRIPTION("Common driver for OTP controller"); |