#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
#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)
#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 | \
{
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);
}
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) &
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)
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;
dev_dbg(priv->dev, "transfer error %x!\n", priv->msg_err);
if (priv->msg_err & XLP9XX_I2C_INTEN_BUSERR)
xlp9xx_i2c_init(priv);
- return -EIO;
+ return (priv->msg_err & XLP9XX_I2C_INTEN_NACKADDR) ?
+ -ENXIO : -EIO;
}
if (timeleft == 0) {
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)
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 = {