diff options
Diffstat (limited to 'drivers/i2c/busses')
| -rw-r--r-- | drivers/i2c/busses/i2c-xlp9xx.c | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-xlp9xx.c b/drivers/i2c/busses/i2c-xlp9xx.c index 1f6d78087af9..42dd1fa0b644 100644 --- a/drivers/i2c/busses/i2c-xlp9xx.c +++ b/drivers/i2c/busses/i2c-xlp9xx.c @@ -16,6 +16,7 @@ #include <linux/kernel.h> #include <linux/module.h> #include <linux/platform_device.h> +#include <linux/delay.h> #define XLP9XX_I2C_DIV 0x0 #define XLP9XX_I2C_CTRL 0x1 @@ -36,6 +37,8 @@ #define XLP9XX_I2C_TIMEOUT 0X10 #define XLP9XX_I2C_GENCALLADDR 0x11 +#define XLP9XX_I2C_STATUS_BUSY BIT(0) + #define XLP9XX_I2C_CMD_START BIT(7) #define XLP9XX_I2C_CMD_STOP BIT(6) #define XLP9XX_I2C_CMD_READ BIT(5) @@ -71,6 +74,7 @@ #define XLP9XX_I2C_HIGH_FREQ 400000 #define XLP9XX_I2C_FIFO_SIZE 0x80U #define XLP9XX_I2C_TIMEOUT_MS 1000 +#define XLP9XX_I2C_BUSY_TIMEOUT 50 #define XLP9XX_I2C_FIFO_WCNT_MASK 0xff #define XLP9XX_I2C_STATUS_ERRMASK (XLP9XX_I2C_INTEN_ARLOST | \ @@ -241,6 +245,26 @@ xfer_done: return IRQ_HANDLED; } +static int xlp9xx_i2c_check_bus_status(struct xlp9xx_i2c_dev *priv) +{ + u32 status; + u32 busy_timeout = XLP9XX_I2C_BUSY_TIMEOUT; + + while (busy_timeout) { + status = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_STATUS); + if ((status & XLP9XX_I2C_STATUS_BUSY) == 0) + break; + + busy_timeout--; + usleep_range(1000, 1100); + } + + if (!busy_timeout) + return -EIO; + + return 0; +} + static int xlp9xx_i2c_init(struct xlp9xx_i2c_dev *priv) { u32 prescale; @@ -363,6 +387,14 @@ static int xlp9xx_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int i, ret; struct xlp9xx_i2c_dev *priv = i2c_get_adapdata(adap); + ret = xlp9xx_i2c_check_bus_status(priv); + if (ret) { + xlp9xx_i2c_init(priv); + ret = xlp9xx_i2c_check_bus_status(priv); + if (ret) + return ret; + } + for (i = 0; i < num; i++) { ret = xlp9xx_i2c_xfer_msg(priv, &msgs[i], i == num - 1); if (ret != 0) |