---

yaml
---
r: 333390
b: refs/heads/master
c: dd74548
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 4a7ec4eda58269a507501f240955d99312fdfd5f
+refs/heads/master: dd74548ddece4b9d68e5528287a272fa552c81d0

trunk/drivers/i2c/busses/i2c-omap.c

@@ -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 @@ omap_i2c_isr(int this_irq, void *dev_id)
 		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 @@ omap_i2c_isr(int this_irq, void *dev_id)
 			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);