diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-s3c2410.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-s3c2410.c | 21 |
1 files changed, 18 insertions, 3 deletions
diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c index d27072b2249..72902e0bbfa 100644 --- a/drivers/i2c/busses/i2c-s3c2410.c +++ b/drivers/i2c/busses/i2c-s3c2410.c @@ -35,9 +35,9 @@ #include <linux/clk.h> #include <linux/cpufreq.h> #include <linux/slab.h> +#include <linux/io.h> #include <asm/irq.h> -#include <asm/io.h> #include <plat/regs-iic.h> #include <plat/iic.h> @@ -482,7 +482,8 @@ static int s3c24xx_i2c_set_master(struct s3c24xx_i2c *i2c) static int s3c24xx_i2c_doxfer(struct s3c24xx_i2c *i2c, struct i2c_msg *msgs, int num) { - unsigned long timeout; + unsigned long iicstat, timeout; + int spins = 20; int ret; if (i2c->suspended) @@ -521,7 +522,21 @@ static int s3c24xx_i2c_doxfer(struct s3c24xx_i2c *i2c, /* ensure the stop has been through the bus */ - msleep(1); + dev_dbg(i2c->dev, "waiting for bus idle\n"); + + /* first, try busy waiting briefly */ + do { + iicstat = readl(i2c->regs + S3C2410_IICSTAT); + } while ((iicstat & S3C2410_IICSTAT_START) && --spins); + + /* if that timed out sleep */ + if (!spins) { + msleep(1); + iicstat = readl(i2c->regs + S3C2410_IICSTAT); + } + + if (iicstat & S3C2410_IICSTAT_START) + dev_warn(i2c->dev, "timeout waiting for bus idle\n"); out: return ret; |