diff options
Diffstat (limited to 'drivers/char/bfin-otp.c')
| -rw-r--r-- | drivers/char/bfin-otp.c | 173 |
1 files changed, 129 insertions, 44 deletions
diff --git a/drivers/char/bfin-otp.c b/drivers/char/bfin-otp.c index 0a01329..e3dd24b 100644 --- a/drivers/char/bfin-otp.c +++ b/drivers/char/bfin-otp.c @@ -1,8 +1,7 @@ /* * Blackfin On-Chip OTP Memory Interface - * Supports BF52x/BF54x * - * Copyright 2007-2008 Analog Devices Inc. + * Copyright 2007-2009 Analog Devices Inc. * * Enter bugs at http://blackfin.uclinux.org/ * @@ -17,8 +16,10 @@ #include <linux/module.h> #include <linux/mutex.h> #include <linux/types.h> +#include <mtd/mtd-abi.h> #include <asm/blackfin.h> +#include <asm/bfrom.h> #include <asm/uaccess.h> #define stamp(fmt, args...) pr_debug("%s:%i: " fmt "\n", __func__, __LINE__, ## args) @@ -30,39 +31,6 @@ static DEFINE_MUTEX(bfin_otp_lock); -/* OTP Boot ROM functions */ -#define _BOOTROM_OTP_COMMAND 0xEF000018 -#define _BOOTROM_OTP_READ 0xEF00001A -#define _BOOTROM_OTP_WRITE 0xEF00001C - -static u32 (* const otp_command)(u32 command, u32 value) = (void *)_BOOTROM_OTP_COMMAND; -static u32 (* const otp_read)(u32 page, u32 flags, u64 *page_content) = (void *)_BOOTROM_OTP_READ; -static u32 (* const otp_write)(u32 page, u32 flags, u64 *page_content) = (void *)_BOOTROM_OTP_WRITE; - -/* otp_command(): defines for "command" */ -#define OTP_INIT 0x00000001 -#define OTP_CLOSE 0x00000002 - -/* otp_{read,write}(): defines for "flags" */ -#define OTP_LOWER_HALF 0x00000000 /* select upper/lower 64-bit half (bit 0) */ -#define OTP_UPPER_HALF 0x00000001 -#define OTP_NO_ECC 0x00000010 /* do not use ECC */ -#define OTP_LOCK 0x00000020 /* sets page protection bit for page */ -#define OTP_ACCESS_READ 0x00001000 -#define OTP_ACCESS_READWRITE 0x00002000 - -/* Return values for all functions */ -#define OTP_SUCCESS 0x00000000 -#define OTP_MASTER_ERROR 0x001 -#define OTP_WRITE_ERROR 0x003 -#define OTP_READ_ERROR 0x005 -#define OTP_ACC_VIO_ERROR 0x009 -#define OTP_DATA_MULT_ERROR 0x011 -#define OTP_ECC_MULT_ERROR 0x021 -#define OTP_PREV_WR_ERROR 0x041 -#define OTP_DATA_SB_WARN 0x100 -#define OTP_ECC_SB_WARN 0x200 - /** * bfin_otp_read - Read OTP pages * @@ -86,9 +54,11 @@ static ssize_t bfin_otp_read(struct file *file, char __user *buff, size_t count, page = *pos / (sizeof(u64) * 2); while (bytes_done < count) { flags = (*pos % (sizeof(u64) * 2) ? OTP_UPPER_HALF : OTP_LOWER_HALF); - stamp("processing page %i (%s)", page, (flags == OTP_UPPER_HALF ? "upper" : "lower")); - ret = otp_read(page, flags, &content); + stamp("processing page %i (0x%x:%s)", page, flags, + (flags & OTP_UPPER_HALF ? "upper" : "lower")); + ret = bfrom_OtpRead(page, flags, &content); if (ret & OTP_MASTER_ERROR) { + stamp("error from otp: 0x%x", ret); bytes_done = -EIO; break; } @@ -96,7 +66,7 @@ static ssize_t bfin_otp_read(struct file *file, char __user *buff, size_t count, bytes_done = -EFAULT; break; } - if (flags == OTP_UPPER_HALF) + if (flags & OTP_UPPER_HALF) ++page; bytes_done += sizeof(content); *pos += sizeof(content); @@ -108,14 +78,53 @@ static ssize_t bfin_otp_read(struct file *file, char __user *buff, size_t count, } #ifdef CONFIG_BFIN_OTP_WRITE_ENABLE +static bool allow_writes; + +/** + * bfin_otp_init_timing - setup OTP timing parameters + * + * Required before doing any write operation. Algorithms from HRM. + */ +static u32 bfin_otp_init_timing(void) +{ + u32 tp1, tp2, tp3, timing; + + tp1 = get_sclk() / 1000000; + tp2 = (2 * get_sclk() / 10000000) << 8; + tp3 = (0x1401) << 15; + timing = tp1 | tp2 | tp3; + if (bfrom_OtpCommand(OTP_INIT, timing)) + return 0; + + return timing; +} + +/** + * bfin_otp_deinit_timing - set timings to only allow reads + * + * Should be called after all writes are done. + */ +static void bfin_otp_deinit_timing(u32 timing) +{ + /* mask bits [31:15] so that any attempts to write fail */ + bfrom_OtpCommand(OTP_CLOSE, 0); + bfrom_OtpCommand(OTP_INIT, timing & ~(-1 << 15)); + bfrom_OtpCommand(OTP_CLOSE, 0); +} + /** - * bfin_otp_write - Write OTP pages + * bfin_otp_write - write OTP pages * * All writes must be in half page chunks (half page == 64 bits). */ static ssize_t bfin_otp_write(struct file *filp, const char __user *buff, size_t count, loff_t *pos) { - stampit(); + ssize_t bytes_done; + u32 timing, page, base_flags, flags, ret; + u64 content; + + if (!allow_writes) + return -EACCES; if (count % sizeof(u64)) return -EMSGSIZE; @@ -123,20 +132,96 @@ static ssize_t bfin_otp_write(struct file *filp, const char __user *buff, size_t if (mutex_lock_interruptible(&bfin_otp_lock)) return -ERESTARTSYS; - /* need otp_init() documentation before this can be implemented */ + stampit(); + + timing = bfin_otp_init_timing(); + if (timing == 0) { + mutex_unlock(&bfin_otp_lock); + return -EIO; + } + + base_flags = OTP_CHECK_FOR_PREV_WRITE; + + bytes_done = 0; + page = *pos / (sizeof(u64) * 2); + while (bytes_done < count) { + flags = base_flags | (*pos % (sizeof(u64) * 2) ? OTP_UPPER_HALF : OTP_LOWER_HALF); + stamp("processing page %i (0x%x:%s) from %p", page, flags, + (flags & OTP_UPPER_HALF ? "upper" : "lower"), buff + bytes_done); + if (copy_from_user(&content, buff + bytes_done, sizeof(content))) { + bytes_done = -EFAULT; + break; + } + ret = bfrom_OtpWrite(page, flags, &content); + if (ret & OTP_MASTER_ERROR) { + stamp("error from otp: 0x%x", ret); + bytes_done = -EIO; + break; + } + if (flags & OTP_UPPER_HALF) + ++page; + bytes_done += sizeof(content); + *pos += sizeof(content); + } + + bfin_otp_deinit_timing(timing); mutex_unlock(&bfin_otp_lock); + return bytes_done; +} + +static long bfin_otp_ioctl(struct file *filp, unsigned cmd, unsigned long arg) +{ + stampit(); + + switch (cmd) { + case OTPLOCK: { + u32 timing; + int ret = -EIO; + + if (!allow_writes) + return -EACCES; + + if (mutex_lock_interruptible(&bfin_otp_lock)) + return -ERESTARTSYS; + + timing = bfin_otp_init_timing(); + if (timing) { + u32 otp_result = bfrom_OtpWrite(arg, OTP_LOCK, NULL); + stamp("locking page %lu resulted in 0x%x", arg, otp_result); + if (!(otp_result & OTP_MASTER_ERROR)) + ret = 0; + + bfin_otp_deinit_timing(timing); + } + + mutex_unlock(&bfin_otp_lock); + + return ret; + } + + case MEMLOCK: + allow_writes = false; + return 0; + + case MEMUNLOCK: + allow_writes = true; + return 0; + } + return -EINVAL; } #else # define bfin_otp_write NULL +# define bfin_otp_ioctl NULL #endif static struct file_operations bfin_otp_fops = { - .owner = THIS_MODULE, - .read = bfin_otp_read, - .write = bfin_otp_write, + .owner = THIS_MODULE, + .unlocked_ioctl = bfin_otp_ioctl, + .read = bfin_otp_read, + .write = bfin_otp_write, }; static struct miscdevice bfin_otp_misc_device = { |
