diff options
Diffstat (limited to 'drivers/hwmon/applesmc.c')
| -rw-r--r-- | drivers/hwmon/applesmc.c | 32 |
1 files changed, 24 insertions, 8 deletions
diff --git a/drivers/hwmon/applesmc.c b/drivers/hwmon/applesmc.c index b401975bc0d..d5bd0cadbf3 100644 --- a/drivers/hwmon/applesmc.c +++ b/drivers/hwmon/applesmc.c @@ -191,6 +191,26 @@ static int __wait_status(u8 val) } /* + * special treatment of command port - on newer macbooks, it seems necessary + * to resend the command byte before polling the status again. Callers must + * hold applesmc_lock. + */ +static int send_command(u8 cmd) +{ + int i; + for (i = 0; i < 1000; i++) { + outb(cmd, APPLESMC_CMD_PORT); + udelay(5); + if ((inb(APPLESMC_CMD_PORT) & APPLESMC_STATUS_MASK) == 0x0c) + return 0; + udelay(5); + } + printk(KERN_WARNING "applesmc: command failed: %x -> %x\n", + cmd, inb(APPLESMC_CMD_PORT)); + return -EIO; +} + +/* * applesmc_read_key - reads len bytes from a given key, and put them in buffer. * Returns zero on success or a negative error on failure. Callers must * hold applesmc_lock. @@ -205,8 +225,7 @@ static int applesmc_read_key(const char* key, u8* buffer, u8 len) return -EINVAL; } - outb(APPLESMC_READ_CMD, APPLESMC_CMD_PORT); - if (__wait_status(0x0c)) + if (send_command(APPLESMC_READ_CMD)) return -EIO; for (i = 0; i < 4; i++) { @@ -249,8 +268,7 @@ static int applesmc_write_key(const char* key, u8* buffer, u8 len) return -EINVAL; } - outb(APPLESMC_WRITE_CMD, APPLESMC_CMD_PORT); - if (__wait_status(0x0c)) + if (send_command(APPLESMC_WRITE_CMD)) return -EIO; for (i = 0; i < 4; i++) { @@ -284,8 +302,7 @@ static int applesmc_get_key_at_index(int index, char* key) readkey[2] = index >> 8; readkey[3] = index; - outb(APPLESMC_GET_KEY_BY_INDEX_CMD, APPLESMC_CMD_PORT); - if (__wait_status(0x0c)) + if (send_command(APPLESMC_GET_KEY_BY_INDEX_CMD)) return -EIO; for (i = 0; i < 4; i++) { @@ -315,8 +332,7 @@ static int applesmc_get_key_type(char* key, char* type) { int i; - outb(APPLESMC_GET_KEY_TYPE_CMD, APPLESMC_CMD_PORT); - if (__wait_status(0x0c)) + if (send_command(APPLESMC_GET_KEY_TYPE_CMD)) return -EIO; for (i = 0; i < 4; i++) { |