X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=blobdiff_plain;f=drivers%2Fi2c%2Fbusses%2Fi2c-davinci.c;h=af3846eda9858e15bd233aa6fe3172333fac5971;hp=cce5a614758d37b84f8de5e93670b1a93f2e3179;hb=82638844d9a8581bbf33201cc209a14876eca167;hpb=bd45ac0c5daae35e7c71138172e63df5cf644cf6

diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c
index cce5a614758d..af3846eda985 100644
--- a/drivers/i2c/busses/i2c-davinci.c
+++ b/drivers/i2c/busses/i2c-davinci.c
@@ -85,6 +85,7 @@
 #define DAVINCI_I2C_MDR_MST	(1 << 10)
 #define DAVINCI_I2C_MDR_TRX	(1 << 9)
 #define DAVINCI_I2C_MDR_XA	(1 << 8)
+#define DAVINCI_I2C_MDR_RM	(1 << 7)
 #define DAVINCI_I2C_MDR_IRS	(1 << 5)
 
 #define DAVINCI_I2C_IMR_AAS	(1 << 6)
@@ -112,6 +113,7 @@ struct davinci_i2c_dev {
 	u8			*buf;
 	size_t			buf_len;
 	int			irq;
+	u8			terminate;
 	struct i2c_adapter	adapter;
 };
 
@@ -142,6 +144,7 @@ static int i2c_davinci_init(struct davinci_i2c_dev *dev)
 	struct davinci_i2c_platform_data *pdata = dev->dev->platform_data;
 	u16 psc;
 	u32 clk;
+	u32 d;
 	u32 clkh;
 	u32 clkl;
 	u32 input_clock = clk_get_rate(dev->clk);
@@ -171,23 +174,29 @@ static int i2c_davinci_init(struct davinci_i2c_dev *dev)
 	 *       if PSC > 1 , d = 5
 	 */
 
-	psc = 26; /* To get 1MHz clock */
+	/* get minimum of 7 MHz clock, but max of 12 MHz */
+	psc = (input_clock / 7000000) - 1;
+	if ((input_clock / (psc + 1)) > 12000000)
+		psc++;	/* better to run under spec than over */
+	d = (psc >= 2) ? 5 : 7 - psc;
 
-	clk = ((input_clock / (psc + 1)) / (pdata->bus_freq * 1000)) - 10;
-	clkh = (50 * clk) / 100;
+	clk = ((input_clock / (psc + 1)) / (pdata->bus_freq * 1000)) - (d << 1);
+	clkh = clk >> 1;
 	clkl = clk - clkh;
 
 	davinci_i2c_write_reg(dev, DAVINCI_I2C_PSC_REG, psc);
 	davinci_i2c_write_reg(dev, DAVINCI_I2C_CLKH_REG, clkh);
 	davinci_i2c_write_reg(dev, DAVINCI_I2C_CLKL_REG, clkl);
 
-	dev_dbg(dev->dev, "CLK  = %d\n", clk);
+	dev_dbg(dev->dev, "input_clock = %d, CLK = %d\n", input_clock, clk);
 	dev_dbg(dev->dev, "PSC  = %d\n",
 		davinci_i2c_read_reg(dev, DAVINCI_I2C_PSC_REG));
 	dev_dbg(dev->dev, "CLKL = %d\n",
 		davinci_i2c_read_reg(dev, DAVINCI_I2C_CLKL_REG));
 	dev_dbg(dev->dev, "CLKH = %d\n",
 		davinci_i2c_read_reg(dev, DAVINCI_I2C_CLKH_REG));
+	dev_dbg(dev->dev, "bus_freq = %dkHz, bus_delay = %d\n",
+		pdata->bus_freq, pdata->bus_delay);
 
 	/* Take the I2C module out of reset: */
 	w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
@@ -233,7 +242,6 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop)
 	struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
 	struct davinci_i2c_platform_data *pdata = dev->dev->platform_data;
 	u32 flag;
-	u32 stat;
 	u16 w;
 	int r;
 
@@ -254,12 +262,9 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop)
 
 	davinci_i2c_write_reg(dev, DAVINCI_I2C_CNT_REG, dev->buf_len);
 
-	init_completion(&dev->cmd_complete);
+	INIT_COMPLETION(dev->cmd_complete);
 	dev->cmd_err = 0;
 
-	/* Clear any pending interrupts by reading the IVR */
-	stat = davinci_i2c_read_reg(dev, DAVINCI_I2C_IVR_REG);
-
 	/* Take I2C out of reset, configure it as master and set the
 	 * start bit */
 	flag = DAVINCI_I2C_MDR_IRS | DAVINCI_I2C_MDR_MST | DAVINCI_I2C_MDR_STT;
@@ -280,20 +285,34 @@ i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop)
 		MOD_REG_BIT(w, DAVINCI_I2C_IMR_XRDY, 1);
 	davinci_i2c_write_reg(dev, DAVINCI_I2C_IMR_REG, w);
 
+	dev->terminate = 0;
 	/* write the data into mode register */
 	davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag);
 
 	r = wait_for_completion_interruptible_timeout(&dev->cmd_complete,
 						      DAVINCI_I2C_TIMEOUT);
-	dev->buf_len = 0;
-	if (r < 0)
-		return r;
-
 	if (r == 0) {
 		dev_err(dev->dev, "controller timed out\n");
 		i2c_davinci_init(dev);
+		dev->buf_len = 0;
 		return -ETIMEDOUT;
 	}
+	if (dev->buf_len) {
+		/* This should be 0 if all bytes were transferred
+		 * or dev->cmd_err denotes an error.
+		 * A signal may have aborted the transfer.
+		 */
+		if (r >= 0) {
+			dev_err(dev->dev, "abnormal termination buf_len=%i\n",
+				dev->buf_len);
+			r = -EREMOTEIO;
+		}
+		dev->terminate = 1;
+		wmb();
+		dev->buf_len = 0;
+	}
+	if (r < 0)
+		return r;
 
 	/* no error */
 	if (likely(!dev->cmd_err))
@@ -328,7 +347,7 @@ i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
 	int i;
 	int ret;
 
-	dev_dbg(dev->dev, "%s: msgs: %d\n", __FUNCTION__, num);
+	dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num);
 
 	ret = i2c_davinci_wait_bus_not_busy(dev, 1);
 	if (ret < 0) {
@@ -338,12 +357,11 @@ i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
 
 	for (i = 0; i < num; i++) {
 		ret = i2c_davinci_xfer_msg(adap, &msgs[i], (i == (num - 1)));
+		dev_dbg(dev->dev, "%s [%d/%d] ret: %d\n", __func__, i + 1, num,
+			ret);
 		if (ret < 0)
 			return ret;
 	}
-
-	dev_dbg(dev->dev, "%s:%d ret: %d\n", __FUNCTION__, __LINE__, ret);
-
 	return num;
 }
 
@@ -352,6 +370,27 @@ static u32 i2c_davinci_func(struct i2c_adapter *adap)
 	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
 }
 
+static void terminate_read(struct davinci_i2c_dev *dev)
+{
+	u16 w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
+	w |= DAVINCI_I2C_MDR_NACK;
+	davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w);
+
+	/* Throw away data */
+	davinci_i2c_read_reg(dev, DAVINCI_I2C_DRR_REG);
+	if (!dev->terminate)
+		dev_err(dev->dev, "RDR IRQ while no data requested\n");
+}
+static void terminate_write(struct davinci_i2c_dev *dev)
+{
+	u16 w = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
+	w |= DAVINCI_I2C_MDR_RM | DAVINCI_I2C_MDR_STP;
+	davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, w);
+
+	if (!dev->terminate)
+		dev_err(dev->dev, "TDR IRQ while no data to send\n");
+}
+
 /*
  * Interrupt service routine. This gets called whenever an I2C interrupt
  * occurs.
@@ -364,7 +403,7 @@ static irqreturn_t i2c_davinci_isr(int this_irq, void *dev_id)
 	u16 w;
 
 	while ((stat = davinci_i2c_read_reg(dev, DAVINCI_I2C_IVR_REG))) {
-		dev_dbg(dev->dev, "%s: stat=0x%x\n", __FUNCTION__, stat);
+		dev_dbg(dev->dev, "%s: stat=0x%x\n", __func__, stat);
 		if (count++ == 100) {
 			dev_warn(dev->dev, "Too much work in one IRQ\n");
 			break;
@@ -372,19 +411,21 @@ static irqreturn_t i2c_davinci_isr(int this_irq, void *dev_id)
 
 		switch (stat) {
 		case DAVINCI_I2C_IVR_AL:
+			/* Arbitration lost, must retry */
 			dev->cmd_err |= DAVINCI_I2C_STR_AL;
+			dev->buf_len = 0;
 			complete(&dev->cmd_complete);
 			break;
 
 		case DAVINCI_I2C_IVR_NACK:
 			dev->cmd_err |= DAVINCI_I2C_STR_NACK;
+			dev->buf_len = 0;
 			complete(&dev->cmd_complete);
 			break;
 
 		case DAVINCI_I2C_IVR_ARDY:
-			w = davinci_i2c_read_reg(dev, DAVINCI_I2C_STR_REG);
-			MOD_REG_BIT(w, DAVINCI_I2C_STR_ARDY, 1);
-			davinci_i2c_write_reg(dev, DAVINCI_I2C_STR_REG, w);
+			davinci_i2c_write_reg(dev,
+				DAVINCI_I2C_STR_REG, DAVINCI_I2C_STR_ARDY);
 			complete(&dev->cmd_complete);
 			break;
 
@@ -397,15 +438,13 @@ static irqreturn_t i2c_davinci_isr(int this_irq, void *dev_id)
 				if (dev->buf_len)
 					continue;
 
-				w = davinci_i2c_read_reg(dev,
-							 DAVINCI_I2C_STR_REG);
-				MOD_REG_BIT(w, DAVINCI_I2C_IMR_RRDY, 0);
 				davinci_i2c_write_reg(dev,
-						      DAVINCI_I2C_STR_REG,
-						      w);
-			} else
-				dev_err(dev->dev, "RDR IRQ while no "
-					"data requested\n");
+					DAVINCI_I2C_STR_REG,
+					DAVINCI_I2C_IMR_RRDY);
+			} else {
+				/* signal can terminate transfer */
+				terminate_read(dev);
+			}
 			break;
 
 		case DAVINCI_I2C_IVR_XRDY:
@@ -422,15 +461,15 @@ static irqreturn_t i2c_davinci_isr(int this_irq, void *dev_id)
 				davinci_i2c_write_reg(dev,
 						      DAVINCI_I2C_IMR_REG,
 						      w);
-			} else
-				dev_err(dev->dev, "TDR IRQ while no data to "
-					"send\n");
+			} else {
+				/* signal can terminate transfer */
+				terminate_write(dev);
+			}
 			break;
 
 		case DAVINCI_I2C_IVR_SCD:
-			w = davinci_i2c_read_reg(dev, DAVINCI_I2C_STR_REG);
-			MOD_REG_BIT(w, DAVINCI_I2C_STR_SCD, 1);
-			davinci_i2c_write_reg(dev, DAVINCI_I2C_STR_REG, w);
+			davinci_i2c_write_reg(dev,
+				DAVINCI_I2C_STR_REG, DAVINCI_I2C_STR_SCD);
 			complete(&dev->cmd_complete);
 			break;
 
@@ -480,6 +519,7 @@ static int davinci_i2c_probe(struct platform_device *pdev)
 		goto err_release_region;
 	}
 
+	init_completion(&dev->cmd_complete);
 	dev->dev = get_device(&pdev->dev);
 	dev->irq = irq->start;
 	platform_set_drvdata(pdev, dev);
@@ -558,6 +598,9 @@ static int davinci_i2c_remove(struct platform_device *pdev)
 	return 0;
 }
 
+/* work with hotplug and coldplug */
+MODULE_ALIAS("platform:i2c_davinci");
+
 static struct platform_driver davinci_i2c_driver = {
 	.probe		= davinci_i2c_probe,
 	.remove		= davinci_i2c_remove,