diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-xlp9xx.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-xlp9xx.c | 78 |
1 files changed, 65 insertions, 13 deletions
diff --git a/drivers/i2c/busses/i2c-xlp9xx.c b/drivers/i2c/busses/i2c-xlp9xx.c index b970bf8f38e5..eb8913eba0c5 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 | \ @@ -125,7 +129,16 @@ static void xlp9xx_i2c_update_rx_fifo_thres(struct xlp9xx_i2c_dev *priv) { u32 thres; - thres = min(priv->msg_buf_remaining, XLP9XX_I2C_FIFO_SIZE); + if (priv->len_recv) + /* interrupt after the first read to examine + * the length byte before proceeding further + */ + thres = 1; + else if (priv->msg_buf_remaining > XLP9XX_I2C_FIFO_SIZE) + thres = XLP9XX_I2C_FIFO_SIZE; + else + thres = priv->msg_buf_remaining; + xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_MFIFOCTRL, thres << XLP9XX_I2C_MFIFOCTRL_HITH_SHIFT); } @@ -144,7 +157,7 @@ static void xlp9xx_i2c_fill_tx_fifo(struct xlp9xx_i2c_dev *priv) static void xlp9xx_i2c_drain_rx_fifo(struct xlp9xx_i2c_dev *priv) { - u32 len, i; + u32 len, i, val; u8 rlen, *buf = priv->msg_buf; len = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_FIFOWCNT) & @@ -156,19 +169,27 @@ static void xlp9xx_i2c_drain_rx_fifo(struct xlp9xx_i2c_dev *priv) rlen = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_MRXFIFO); *buf++ = rlen; len--; + if (priv->client_pec) ++rlen; /* update remaining bytes and message length */ priv->msg_buf_remaining = rlen; priv->msg_len = rlen + 1; priv->len_recv = false; - } - len = min(priv->msg_buf_remaining, len); - for (i = 0; i < len; i++, buf++) - *buf = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_MRXFIFO); + /* Update transfer length to read only actual data */ + val = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_CTRL); + val = (val & ~XLP9XX_I2C_CTRL_MCTLEN_MASK) | + ((rlen + 1) << XLP9XX_I2C_CTRL_MCTLEN_SHIFT); + xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_CTRL, val); + } else { + len = min(priv->msg_buf_remaining, len); + for (i = 0; i < len; i++, buf++) + *buf = xlp9xx_read_i2c_reg(priv, XLP9XX_I2C_MRXFIFO); + + priv->msg_buf_remaining -= len; + } - priv->msg_buf_remaining -= len; priv->msg_buf = buf; if (priv->msg_buf_remaining) @@ -224,6 +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; @@ -311,7 +352,9 @@ static int xlp9xx_i2c_xfer_msg(struct xlp9xx_i2c_dev *priv, struct i2c_msg *msg, /* set cmd reg */ cmd = XLP9XX_I2C_CMD_START; - cmd |= (priv->msg_read ? XLP9XX_I2C_CMD_READ : XLP9XX_I2C_CMD_WRITE); + if (msg->len) + cmd |= (priv->msg_read ? + XLP9XX_I2C_CMD_READ : XLP9XX_I2C_CMD_WRITE); if (last_msg) cmd |= XLP9XX_I2C_CMD_STOP; @@ -320,11 +363,12 @@ static int xlp9xx_i2c_xfer_msg(struct xlp9xx_i2c_dev *priv, struct i2c_msg *msg, timeleft = msecs_to_jiffies(XLP9XX_I2C_TIMEOUT_MS); timeleft = wait_for_completion_timeout(&priv->msg_complete, timeleft); - if (priv->msg_err) { + if (priv->msg_err & XLP9XX_I2C_INTEN_BUSERR) { dev_dbg(priv->dev, "transfer error %x!\n", priv->msg_err); - if (priv->msg_err & XLP9XX_I2C_INTEN_BUSERR) - xlp9xx_i2c_init(priv); + xlp9xx_write_i2c_reg(priv, XLP9XX_I2C_CMD, XLP9XX_I2C_CMD_STOP); return -EIO; + } else if (priv->msg_err & XLP9XX_I2C_INTEN_NACKADDR) { + return -ENXIO; } if (timeleft == 0) { @@ -345,6 +389,14 @@ 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) @@ -356,8 +408,8 @@ static int xlp9xx_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, static u32 xlp9xx_i2c_functionality(struct i2c_adapter *adapter) { - return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C | - I2C_FUNC_10BIT_ADDR; + return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_SMBUS_READ_BLOCK_DATA | + I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR; } static const struct i2c_algorithm xlp9xx_i2c_algo = { |