diff options
| -rw-r--r-- | drivers/hwmon/applesmc.c | 70 |
1 files changed, 46 insertions, 24 deletions
diff --git a/drivers/hwmon/applesmc.c b/drivers/hwmon/applesmc.c index 4d937a18fad..28270886051 100644 --- a/drivers/hwmon/applesmc.c +++ b/drivers/hwmon/applesmc.c @@ -55,9 +55,9 @@ /* wait up to 32 ms for a status change. */ #define APPLESMC_MIN_WAIT 0x0010 +#define APPLESMC_RETRY_WAIT 0x0100 #define APPLESMC_MAX_WAIT 0x8000 -#define APPLESMC_STATUS_MASK 0x0f #define APPLESMC_READ_CMD 0x10 #define APPLESMC_WRITE_CMD 0x11 #define APPLESMC_GET_KEY_BY_INDEX_CMD 0x12 @@ -162,51 +162,68 @@ static unsigned int key_at_index; static struct workqueue_struct *applesmc_led_wq; /* - * __wait_status - Wait up to 32ms for the status port to get a certain value - * (masked with 0x0f), returning zero if the value is obtained. Callers must + * wait_read - Wait for a byte to appear on SMC port. Callers must * hold applesmc_lock. */ -static int __wait_status(u8 val) +static int wait_read(void) { + u8 status; int us; - - val = val & APPLESMC_STATUS_MASK; - for (us = APPLESMC_MIN_WAIT; us < APPLESMC_MAX_WAIT; us <<= 1) { udelay(us); - if ((inb(APPLESMC_CMD_PORT) & APPLESMC_STATUS_MASK) == val) + status = inb(APPLESMC_CMD_PORT); + /* read: wait for smc to settle */ + if (status & 0x01) return 0; } + pr_warn("wait_read() fail: 0x%02x\n", status); return -EIO; } /* - * 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. + * send_byte - Write to SMC port, retrying when necessary. Callers + * must hold applesmc_lock. */ -static int send_command(u8 cmd) +static int send_byte(u8 cmd, u16 port) { + u8 status; int us; + + outb(cmd, port); for (us = APPLESMC_MIN_WAIT; us < APPLESMC_MAX_WAIT; us <<= 1) { - outb(cmd, APPLESMC_CMD_PORT); udelay(us); - if ((inb(APPLESMC_CMD_PORT) & APPLESMC_STATUS_MASK) == 0x0c) + status = inb(APPLESMC_CMD_PORT); + /* write: wait for smc to settle */ + if (status & 0x02) + continue; + /* ready: cmd accepted, return */ + if (status & 0x04) return 0; + /* timeout: give up */ + if (us << 1 == APPLESMC_MAX_WAIT) + break; + /* busy: long wait and resend */ + udelay(APPLESMC_RETRY_WAIT); + outb(cmd, port); } + + pr_warn("send_byte(0x%02x, 0x%04x) fail: 0x%02x\n", cmd, port, status); return -EIO; } +static int send_command(u8 cmd) +{ + return send_byte(cmd, APPLESMC_CMD_PORT); +} + static int send_argument(const char *key) { int i; - for (i = 0; i < 4; i++) { - outb(key[i], APPLESMC_DATA_PORT); - if (__wait_status(0x04)) + for (i = 0; i < 4; i++) + if (send_byte(key[i], APPLESMC_DATA_PORT)) return -EIO; - } return 0; } @@ -219,11 +236,14 @@ static int read_smc(u8 cmd, const char *key, u8 *buffer, u8 len) return -EIO; } - outb(len, APPLESMC_DATA_PORT); + if (send_byte(len, APPLESMC_DATA_PORT)) { + pr_warn("%.4s: read len fail\n", key); + return -EIO; + } for (i = 0; i < len; i++) { - if (__wait_status(0x05)) { - pr_warn("%.4s: read data fail\n", key); + if (wait_read()) { + pr_warn("%.4s: read data[%d] fail\n", key, i); return -EIO; } buffer[i] = inb(APPLESMC_DATA_PORT); @@ -241,14 +261,16 @@ static int write_smc(u8 cmd, const char *key, const u8 *buffer, u8 len) return -EIO; } - outb(len, APPLESMC_DATA_PORT); + if (send_byte(len, APPLESMC_DATA_PORT)) { + pr_warn("%.4s: write len fail\n", key); + return -EIO; + } for (i = 0; i < len; i++) { - if (__wait_status(0x04)) { + if (send_byte(buffer[i], APPLESMC_DATA_PORT)) { pr_warn("%s: write data fail\n", key); return -EIO; } - outb(buffer[i], APPLESMC_DATA_PORT); } return 0; |