diff options
| author | Martyn Welch <martyn.welch@gefanuc.com> | 2009-08-13 09:03:02 +0100 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2009-09-11 16:02:11 +1000 |
| commit | d331d8305cba713605854aab63a000fb892353a7 (patch) | |
| tree | 5ee6cea2fe656d5772d79245e296c13b36f60456 /drivers/char/generic_nvram.c | |
| parent | 1d6ed32226326a6e6cd67cd9ee4294bcbb0c9a15 (diff) | |
powerpc/nvram: Enable use Generic NVRAM driver for different size chips
Remove the reliance on a staticly defined NVRAM size, allowing
platforms to support NVRAMs with sizes differing from the standard.
A fall back value is provided for platforms not supporting this extension.
Signed-off-by: Martyn Welch <martyn.welch@gefanuc.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'drivers/char/generic_nvram.c')
| -rw-r--r-- | drivers/char/generic_nvram.c | 27 |
1 files changed, 20 insertions, 7 deletions
diff --git a/drivers/char/generic_nvram.c b/drivers/char/generic_nvram.c index a00869c650d..ef31738c2cb 100644 --- a/drivers/char/generic_nvram.c +++ b/drivers/char/generic_nvram.c @@ -2,7 +2,7 @@ * Generic /dev/nvram driver for architectures providing some * "generic" hooks, that is : * - * nvram_read_byte, nvram_write_byte, nvram_sync + * nvram_read_byte, nvram_write_byte, nvram_sync, nvram_get_size * * Note that an additional hook is supported for PowerMac only * for getting the nvram "partition" informations @@ -28,6 +28,8 @@ #define NVRAM_SIZE 8192 +static ssize_t nvram_len; + static loff_t nvram_llseek(struct file *file, loff_t offset, int origin) { lock_kernel(); @@ -36,7 +38,7 @@ static loff_t nvram_llseek(struct file *file, loff_t offset, int origin) offset += file->f_pos; break; case 2: - offset += NVRAM_SIZE; + offset += nvram_len; break; } if (offset < 0) { @@ -56,9 +58,9 @@ static ssize_t read_nvram(struct file *file, char __user *buf, if (!access_ok(VERIFY_WRITE, buf, count)) return -EFAULT; - if (*ppos >= NVRAM_SIZE) + if (*ppos >= nvram_len) return 0; - for (i = *ppos; count > 0 && i < NVRAM_SIZE; ++i, ++p, --count) + for (i = *ppos; count > 0 && i < nvram_len; ++i, ++p, --count) if (__put_user(nvram_read_byte(i), p)) return -EFAULT; *ppos = i; @@ -74,9 +76,9 @@ static ssize_t write_nvram(struct file *file, const char __user *buf, if (!access_ok(VERIFY_READ, buf, count)) return -EFAULT; - if (*ppos >= NVRAM_SIZE) + if (*ppos >= nvram_len) return 0; - for (i = *ppos; count > 0 && i < NVRAM_SIZE; ++i, ++p, --count) { + for (i = *ppos; count > 0 && i < nvram_len; ++i, ++p, --count) { if (__get_user(c, p)) return -EFAULT; nvram_write_byte(c, i); @@ -133,9 +135,20 @@ static struct miscdevice nvram_dev = { int __init nvram_init(void) { + int ret = 0; + printk(KERN_INFO "Generic non-volatile memory driver v%s\n", NVRAM_VERSION); - return misc_register(&nvram_dev); + ret = misc_register(&nvram_dev); + if (ret != 0) + goto out; + + nvram_len = nvram_get_size(); + if (nvram_len < 0) + nvram_len = NVRAM_SIZE; + +out: + return ret; } void __exit nvram_cleanup(void) |