diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-s3c2410.c')
-rw-r--r-- | drivers/i2c/busses/i2c-s3c2410.c | 61 |
1 files changed, 40 insertions, 21 deletions
diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c index c56886af724e..275f7c42165c 100644 --- a/drivers/i2c/busses/i2c-s3c2410.c +++ b/drivers/i2c/busses/i2c-s3c2410.c @@ -76,6 +76,7 @@ #define QUIRK_HDMIPHY (1 << 1) #define QUIRK_NO_GPIO (1 << 2) #define QUIRK_POLL (1 << 3) +#define QUIRK_ATOMIC (1 << 4) /* Max time to wait for bus to become idle after a xfer (in us) */ #define S3C2410_IDLE_TIMEOUT 5000 @@ -174,7 +175,7 @@ static inline void s3c24xx_i2c_master_complete(struct s3c24xx_i2c *i2c, int ret) if (ret) i2c->msg_idx = ret; - if (!(i2c->quirks & QUIRK_POLL)) + if (!(i2c->quirks & (QUIRK_POLL | QUIRK_ATOMIC))) wake_up(&i2c->wait); } @@ -216,8 +217,17 @@ static bool is_ack(struct s3c24xx_i2c *i2c) int tries; for (tries = 50; tries; --tries) { - if (readl(i2c->regs + S3C2410_IICCON) - & S3C2410_IICCON_IRQPEND) { + unsigned long tmp = readl(i2c->regs + S3C2410_IICCON); + + if (!(tmp & S3C2410_IICCON_ACKEN)) { + /* + * Wait a bit for the bus to stabilize, + * delay estimated experimentally. + */ + usleep_range(100, 200); + return true; + } + if (tmp & S3C2410_IICCON_IRQPEND) { if (!(readl(i2c->regs + S3C2410_IICSTAT) & S3C2410_IICSTAT_LASTBIT)) return true; @@ -270,16 +280,6 @@ static void s3c24xx_i2c_message_start(struct s3c24xx_i2c *i2c, stat |= S3C2410_IICSTAT_START; writel(stat, i2c->regs + S3C2410_IICSTAT); - - if (i2c->quirks & QUIRK_POLL) { - while ((i2c->msg_num != 0) && is_ack(i2c)) { - i2c_s3c_irq_nextbyte(i2c, stat); - stat = readl(i2c->regs + S3C2410_IICSTAT); - - if (stat & S3C2410_IICSTAT_ARBITR) - dev_err(i2c->dev, "deal with arbitration loss\n"); - } - } } static inline void s3c24xx_i2c_stop(struct s3c24xx_i2c *i2c, int ret) @@ -685,7 +685,7 @@ static void s3c24xx_i2c_wait_idle(struct s3c24xx_i2c *i2c) static int s3c24xx_i2c_doxfer(struct s3c24xx_i2c *i2c, struct i2c_msg *msgs, int num) { - unsigned long timeout; + unsigned long timeout = 0; int ret; ret = s3c24xx_i2c_set_master(i2c); @@ -704,17 +704,20 @@ static int s3c24xx_i2c_doxfer(struct s3c24xx_i2c *i2c, s3c24xx_i2c_enable_irq(i2c); s3c24xx_i2c_message_start(i2c, msgs); - if (i2c->quirks & QUIRK_POLL) { - ret = i2c->msg_idx; + if (i2c->quirks & (QUIRK_POLL | QUIRK_ATOMIC)) { + while ((i2c->msg_num != 0) && is_ack(i2c)) { + unsigned long stat = readl(i2c->regs + S3C2410_IICSTAT); - if (ret != num) - dev_dbg(i2c->dev, "incomplete xfer (%d)\n", ret); + i2c_s3c_irq_nextbyte(i2c, stat); - goto out; + stat = readl(i2c->regs + S3C2410_IICSTAT); + if (stat & S3C2410_IICSTAT_ARBITR) + dev_err(i2c->dev, "deal with arbitration loss\n"); + } + } else { + timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5); } - timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5); - ret = i2c->msg_idx; /* @@ -773,6 +776,21 @@ static int s3c24xx_i2c_xfer(struct i2c_adapter *adap, return -EREMOTEIO; } +static int s3c24xx_i2c_xfer_atomic(struct i2c_adapter *adap, + struct i2c_msg *msgs, int num) +{ + struct s3c24xx_i2c *i2c = (struct s3c24xx_i2c *)adap->algo_data; + int ret; + + disable_irq(i2c->irq); + i2c->quirks |= QUIRK_ATOMIC; + ret = s3c24xx_i2c_xfer(adap, msgs, num); + i2c->quirks &= ~QUIRK_ATOMIC; + enable_irq(i2c->irq); + + return ret; +} + /* declare our i2c functionality */ static u32 s3c24xx_i2c_func(struct i2c_adapter *adap) { @@ -783,6 +801,7 @@ static u32 s3c24xx_i2c_func(struct i2c_adapter *adap) /* i2c bus registration info */ static const struct i2c_algorithm s3c24xx_i2c_algorithm = { .master_xfer = s3c24xx_i2c_xfer, + .master_xfer_atomic = s3c24xx_i2c_xfer_atomic, .functionality = s3c24xx_i2c_func, }; |