@@ -193,6 +193,7 @@ struct omap_i2c_dev {
u8 *regs;
size_t buf_len;
struct i2c_adapter adapter;
+ u8 threshold;
u8 fifo_size; /* use as flag and value
* fifo_size==0 implies no fifo
* if set, should be trsh+1
@@ -418,13 +419,6 @@ static int omap_i2c_init(struct omap_i2c_dev *dev)
omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG, scll);
omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG, sclh);
- if (dev->fifo_size) {
- /* Note: setup required fifo size - 1. RTRSH and XTRSH */
- buf = (dev->fifo_size - 1) << 8 | OMAP_I2C_BUF_RXFIF_CLR |
- (dev->fifo_size - 1) | OMAP_I2C_BUF_TXFIF_CLR;
- omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, buf);
- }
-
/* Take the I2C module out of reset: */
omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
@@ -462,6 +456,45 @@ static int omap_i2c_wait_for_bb(struct omap_i2c_dev *dev)
return 0;
}
+static void omap_i2c_resize_fifo(struct omap_i2c_dev *dev, u8 size, bool is_rx)
+{
+ u16 buf;
+
+ if (dev->flags & OMAP_I2C_FLAG_NO_FIFO)
+ return;
+
+ /*
+ * Set up notification threshold based on message size. We're doing
+ * this to try and avoid draining feature as much as possible. Whenever
+ * we have big messages to transfer (bigger than our total fifo size)
+ * then we might use draining feature to transfer the remaining bytes.
+ */
+
+ dev->threshold = clamp(size, (u8) 1, dev->fifo_size);
+
+ buf = omap_i2c_read_reg(dev, OMAP_I2C_BUF_REG);
+
+ if (is_rx) {
+ /* Clear RX Threshold */
+ buf &= ~(0x3f << 8);
+ buf |= ((dev->threshold - 1) << 8) | OMAP_I2C_BUF_RXFIF_CLR;
+ } else {
+ /* Clear TX Threshold */
+ buf &= ~0x3f;
+ buf |= (dev->threshold - 1) | OMAP_I2C_BUF_TXFIF_CLR;
+ }
+
+ omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, buf);
+
+ if (dev->rev < OMAP_I2C_REV_ON_3630_4430)
+ dev->b_hw = 1; /* Enable hardware fixes */
+
+ /* calculate wakeup latency constraint for MPU */
+ if (dev->set_mpu_wkup_lat != NULL)
+ dev->latency = (1000000 * dev->threshold) /
+ (1000 * dev->speed / 8);
+}
+
/*
* Low level master read/write transaction.
*/
@@ -478,6 +511,9 @@ static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
if (msg->len == 0)
return -EINVAL;
+ dev->receiver = !!(msg->flags & I2C_M_RD);
+ omap_i2c_resize_fifo(dev, msg->len, dev->receiver);
+
omap_i2c_write_reg(dev, OMAP_I2C_SA_REG, msg->addr);
/* REVISIT: Could the STB bit of I2C_CON be used with probing? */
@@ -493,7 +529,6 @@ static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
INIT_COMPLETION(dev->cmd_complete);
dev->cmd_err = 0;
- dev->receiver = !!(msg->flags & I2C_M_RD);
w = OMAP_I2C_CON_EN | OMAP_I2C_CON_MST | OMAP_I2C_CON_STT;
@@ -760,12 +795,6 @@ static void omap_i2c_receive_data(struct omap_i2c_dev *dev, u8 num_bytes,
u16 w;
while (num_bytes--) {
- if (!dev->buf_len) {
- dev_err(dev->dev, "%s without data",
- is_rdr ? "RDR" : "RRDY");
- break;
- }
-
w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG);
*dev->buf++ = w;
dev->buf_len--;
@@ -775,10 +804,8 @@ static void omap_i2c_receive_data(struct omap_i2c_dev *dev, u8 num_bytes,
* omap4 is 8 bit wide
*/
if (dev->flags & OMAP_I2C_FLAG_16BIT_DATA_REG) {
- if (dev->buf_len) {
- *dev->buf++ = w >> 8;
- dev->buf_len--;
- }
+ *dev->buf++ = w >> 8;
+ dev->buf_len--;
}
}
}
@@ -789,12 +816,6 @@ static int omap_i2c_transmit_data(struct omap_i2c_dev *dev, u8 num_bytes,
u16 w;
while (num_bytes--) {
- if (!dev->buf_len) {
- dev_err(dev->dev, "%s without data",
- is_xdr ? "XDR" : "XRDY");
- break;
- }
-
w = *dev->buf++;
dev->buf_len--;
@@ -803,10 +824,8 @@ static int omap_i2c_transmit_data(struct omap_i2c_dev *dev, u8 num_bytes,
* omap4 is 8 bit wide
*/
if (dev->flags & OMAP_I2C_FLAG_16BIT_DATA_REG) {
- if (dev->buf_len) {
- w |= *dev->buf++ << 8;
- dev->buf_len--;
- }
+ w |= *dev->buf++ << 8;
+ dev->buf_len--;
}
if (dev->errata & I2C_OMAP_ERRATA_I462) {
@@ -901,8 +920,8 @@ complete:
if (stat & OMAP_I2C_STAT_RRDY) {
u8 num_bytes = 1;
- if (dev->fifo_size)
- num_bytes = dev->fifo_size;
+ if (dev->threshold)
+ num_bytes = dev->threshold;
omap_i2c_receive_data(dev, num_bytes, false);
omap_i2c_ack_stat(dev, OMAP_I2C_STAT_RRDY);
@@ -929,8 +948,8 @@ complete:
u8 num_bytes = 1;
int ret;
- if (dev->fifo_size)
- num_bytes = dev->fifo_size;
+ if (dev->threshold)
+ num_bytes = dev->threshold;
ret = omap_i2c_transmit_data(dev, num_bytes, false);
stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);