diff options
Diffstat (limited to 'drivers/hwmon/applesmc.c')
| -rw-r--r-- | drivers/hwmon/applesmc.c | 101 |
1 files changed, 73 insertions, 28 deletions
diff --git a/drivers/hwmon/applesmc.c b/drivers/hwmon/applesmc.c index 4d937a18fad..3288f13d2d8 100644 --- a/drivers/hwmon/applesmc.c +++ b/drivers/hwmon/applesmc.c @@ -43,6 +43,7 @@ #include <linux/leds.h> #include <linux/hwmon.h> #include <linux/workqueue.h> +#include <linux/err.h> /* data port used by Apple SMC */ #define APPLESMC_DATA_PORT 0x300 @@ -53,11 +54,11 @@ #define APPLESMC_MAX_DATA_LENGTH 32 -/* wait up to 32 ms for a status change. */ +/* wait up to 128 ms for a status change. */ #define APPLESMC_MIN_WAIT 0x0010 -#define APPLESMC_MAX_WAIT 0x8000 +#define APPLESMC_RETRY_WAIT 0x0100 +#define APPLESMC_MAX_WAIT 0x20000 -#define APPLESMC_STATUS_MASK 0x0f #define APPLESMC_READ_CMD 0x10 #define APPLESMC_WRITE_CMD 0x11 #define APPLESMC_GET_KEY_BY_INDEX_CMD 0x12 @@ -162,56 +163,74 @@ 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; } static int read_smc(u8 cmd, const char *key, u8 *buffer, u8 len) { + u8 status, data = 0; int i; if (send_command(cmd) || send_argument(key)) { @@ -219,16 +238,31 @@ static int read_smc(u8 cmd, const char *key, u8 *buffer, u8 len) return -EIO; } - outb(len, APPLESMC_DATA_PORT); + /* This has no effect on newer (2012) SMCs */ + 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); } + /* Read the data port until bit0 is cleared */ + for (i = 0; i < 16; i++) { + udelay(APPLESMC_MIN_WAIT); + status = inb(APPLESMC_CMD_PORT); + if (!(status & 0x01)) + break; + data = inb(APPLESMC_DATA_PORT); + } + if (i) + pr_warn("flushed %d bytes, last value is: %d\n", i, data); + return 0; } @@ -241,14 +275,16 @@ 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; @@ -502,16 +538,25 @@ static int applesmc_init_smcreg_try(void) { struct applesmc_registers *s = &smcreg; bool left_light_sensor, right_light_sensor; + unsigned int count; u8 tmp[1]; int ret; if (s->init_complete) return 0; - ret = read_register_count(&s->key_count); + ret = read_register_count(&count); if (ret) return ret; + if (s->cache && s->key_count != count) { + pr_warn("key count changed from %d to %d\n", + s->key_count, count); + kfree(s->cache); + s->cache = NULL; + } + s->key_count = count; + if (!s->cache) s->cache = kcalloc(s->key_count, sizeof(*s->cache), GFP_KERNEL); if (!s->cache) @@ -899,7 +944,7 @@ static void applesmc_brightness_set(struct led_classdev *led_cdev, ret = queue_work(applesmc_led_wq, &backlight_work); if (debug && (!ret)) - printk(KERN_DEBUG "applesmc: work was already on the queue.\n"); + dev_dbg(led_cdev->dev, "work was already on the queue.\n"); } static ssize_t applesmc_key_count_show(struct device *dev, |