[PATCHv4 00/18] I2C OMAP big cleanup

19 messages, 1 author, 2012-07-03 · open the first message on its own page

[PATCHv4 00/18] I2C OMAP big cleanup

From: Shubhrajyoti D <hidden>
Date: 2012-07-03 14:37:38

Changes since v1:
       - removed tabification on patch 6/17
       - removed dev_err() which was introduced on patch 09/17
Changes since v2:
        - do not set full fifo depth in the RDR interrupt.
        - some changelog updates.
        - rebase to the Wolfram's tree.
Changes since v3:
        - Remove a redundant read of status register
        - Read the dev->buf_len variable instead of the register
        as the information of the remaining bytes is there.

Tested on omap4sdp and 3430sdp.
Functional testing.
Also did suspend resume.
(with omap_fixes_a_3.5rc' of git://git.pwsan.com/linux-2.6 into lkml_master
for 32ktimer fix)

This applies on Wolfram's i2c-embedded/for-next branch
plus the below series
http://www.spinics.net/lists/linux-omap/msg72901.html

Previous disscurssion 
http://www.spinics.net/lists/linux-omap/msg72997.html

are available in the git repository at:
  git://gitorious.org/linus-tree/linus-tree.git for_next/omap/big_cleanup

Felipe Balbi (17):
  i2c: omap: switch to devm_* API
  i2c: omap: simplify num_bytes handling
  i2c: omap: decrease indentation level on data handling
  i2c: omap: add blank lines
  i2c: omap: simplify omap_i2c_ack_stat()
  i2c: omap: split out [XR]DR and [XR]RDY
  i2c: omap: improve i462 errata handling
  i2c: omap: re-factor receive/transmit data loop
  i2c: omap: switch over to do {} while loop
  i2c: omap: ack IRQ in parts
  i2c: omap: switch to platform_get_irq()
  i2c: omap: bus: add a receiver flag
  i2c: omap: simplify errata check
  i2c: omap: always return IRQ_HANDLED
  i2c: omap: simplify IRQ exit path
  i2c: omap: resize fifos before each message
  i2c: omap: get rid of the "complete" label

Shubhrajyoti D (1):
  i2c: omap: remove redundant status read

 drivers/i2c/busses/i2c-omap.c |  392 ++++++++++++++++++++++++-----------------
 1 files changed, 228 insertions(+), 164 deletions(-)

-- 
1.7.5.4

[PATCHv4 01/18] i2c: omap: switch to devm_* API

From: Shubhrajyoti D <hidden>
Date: 2012-07-03 14:37:39

From: Felipe Balbi <redacted>

that helps deleting some boiler plate code
and lets driver-core manage our resources
for us.

Signed-off-by: Felipe Balbi <redacted>
Signed-off-by: Shubhrajyoti D <redacted>
---
 drivers/i2c/busses/i2c-omap.c |   41 ++++++++++++-----------------------------
 1 files changed, 12 insertions(+), 29 deletions(-)
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 2500f19..0946be5 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -962,7 +962,7 @@ omap_i2c_probe(struct platform_device *pdev)
 {
 	struct omap_i2c_dev	*dev;
 	struct i2c_adapter	*adap;
-	struct resource		*mem, *irq, *ioarea;
+	struct resource		*mem, *irq;
 	struct omap_i2c_bus_platform_data *pdata = pdev->dev.platform_data;
 	struct device_node	*node = pdev->dev.of_node;
 	const struct of_device_id *match;
@@ -981,17 +981,16 @@ omap_i2c_probe(struct platform_device *pdev)
 		return -ENODEV;
 	}
 
-	ioarea = request_mem_region(mem->start, resource_size(mem),
-			pdev->name);
-	if (!ioarea) {
-		dev_err(&pdev->dev, "I2C region already claimed\n");
-		return -EBUSY;
+	dev = devm_kzalloc(&pdev->dev, sizeof(struct omap_i2c_dev), GFP_KERNEL);
+	if (!dev) {
+		dev_err(&pdev->dev, "Menory allocation failed\n");
+		return -ENOMEM;
 	}
 
-	dev = kzalloc(sizeof(struct omap_i2c_dev), GFP_KERNEL);
-	if (!dev) {
-		r = -ENOMEM;
-		goto err_release_region;
+	dev->base = devm_request_and_ioremap(&pdev->dev, mem);
+	if (!dev->base) {
+		dev_err(&pdev->dev, "I2C region already claimed\n");
+		return -ENOMEM;
 	}
 
 	match = of_match_device(of_match_ptr(omap_i2c_of_match), &pdev->dev);
@@ -1014,11 +1013,6 @@ omap_i2c_probe(struct platform_device *pdev)
 
 	dev->dev = &pdev->dev;
 	dev->irq = irq->start;
-	dev->base = ioremap(mem->start, resource_size(mem));
-	if (!dev->base) {
-		r = -ENOMEM;
-		goto err_free_mem;
-	}
 
 	platform_set_drvdata(pdev, dev);
 	init_completion(&dev->cmd_complete);
@@ -1076,7 +1070,8 @@ omap_i2c_probe(struct platform_device *pdev)
 
 	isr = (dev->rev < OMAP_I2C_OMAP1_REV_2) ? omap_i2c_omap1_isr :
 								   omap_i2c_isr;
-	r = request_irq(dev->irq, isr, IRQF_NO_SUSPEND, pdev->name, dev);
+	r = devm_request_irq(&pdev->dev, dev->irq, isr, IRQF_NO_SUSPEND,
+			     pdev->name, dev);
 
 	if (r) {
 		dev_err(dev->dev, "failure requesting irq %i\n", dev->irq);
@@ -1100,7 +1095,7 @@ omap_i2c_probe(struct platform_device *pdev)
 	r = i2c_add_numbered_adapter(adap);
 	if (r) {
 		dev_err(dev->dev, "failure adding adapter\n");
-		goto err_free_irq;
+		goto err_unuse_clocks;
 	}
 
 	of_i2c_register_devices(adap);
@@ -1109,18 +1104,12 @@ omap_i2c_probe(struct platform_device *pdev)
 
 	return 0;
 
-err_free_irq:
-	free_irq(dev->irq, dev);
 err_unuse_clocks:
 	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
 	pm_runtime_put(dev->dev);
-	iounmap(dev->base);
 	pm_runtime_disable(&pdev->dev);
 err_free_mem:
 	platform_set_drvdata(pdev, NULL);
-	kfree(dev);
-err_release_region:
-	release_mem_region(mem->start, resource_size(mem));
 
 	return r;
 }
@@ -1128,12 +1117,10 @@ err_release_region:
 static int __devexit omap_i2c_remove(struct platform_device *pdev)
 {
 	struct omap_i2c_dev	*dev = platform_get_drvdata(pdev);
-	struct resource		*mem;
 	int ret;
 
 	platform_set_drvdata(pdev, NULL);
 
-	free_irq(dev->irq, dev);
 	i2c_del_adapter(&dev->adapter);
 	ret = pm_runtime_get_sync(&pdev->dev);
 	if (IS_ERR_VALUE(ret))
@@ -1142,10 +1129,6 @@ static int __devexit omap_i2c_remove(struct platform_device *pdev)
 	omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
 	pm_runtime_put(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
-	iounmap(dev->base);
-	kfree(dev);
-	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	release_mem_region(mem->start, resource_size(mem));
 	return 0;
 }
 
-- 
1.7.5.4

[PATCHv4 02/18] i2c: omap: simplify num_bytes handling

From: Shubhrajyoti D <hidden>
Date: 2012-07-03 14:37:40

From: Felipe Balbi <redacted>

trivial patch, no functional changes

If the fifo is disabled or fifo_size is 0 the num_bytes
is set to 1. Else it is set to fifo_size or in case of a
draining interrupt the remaining bytes in the buff stat.
So the zero check is redundant and can be safely optimised.

Signed-off-by: Felipe Balbi <redacted>
Reviewed-by : Santosh Shilimkar [off-list ref]
Signed-off-by: Shubhrajyoti D <redacted>
---
 drivers/i2c/busses/i2c-omap.c |    6 ++----
 1 files changed, 2 insertions(+), 4 deletions(-)
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 0946be5..440e41f 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -831,8 +831,7 @@ complete:
 							OMAP_I2C_BUFSTAT_REG)
 							>> 8) & 0x3F;
 			}
-			while (num_bytes) {
-				num_bytes--;
+			while (num_bytes--) {
 				w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG);
 				if (dev->buf_len) {
 					*dev->buf++ = w;
@@ -874,8 +873,7 @@ complete:
 							OMAP_I2C_BUFSTAT_REG)
 							& 0x3F;
 			}
-			while (num_bytes) {
-				num_bytes--;
+			while (num_bytes--) {
 				w = 0;
 				if (dev->buf_len) {
 					w = *dev->buf++;
-- 
1.7.5.4

[PATCHv4 03/18] i2c: omap: decrease indentation level on data handling

From: Shubhrajyoti D <hidden>
Date: 2012-07-03 14:37:41

From: Felipe Balbi <redacted>

The patch intends to decrease the indentation level on the
data handling
by using the fact that else of if (dev->buf_len) is same as
if (!dev->buf_len)

if (dev->buf_len) {
	aaa;
} else {
	bbb;
	break;
}

to

if (!dev->buf_len) {
        bbb;
        break;
}
aaa;

Hence no functional changes.

Signed-off-by: Felipe Balbi <redacted>
Reviewed-by : Santosh Shilimkar [off-list ref]
Signed-off-by: Shubhrajyoti D <redacted>
---
 drivers/i2c/busses/i2c-omap.c |   63 ++++++++++++++++++++---------------------
 1 files changed, 31 insertions(+), 32 deletions(-)
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 440e41f..0da00ac 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -832,22 +832,7 @@ complete:
 							>> 8) & 0x3F;
 			}
 			while (num_bytes--) {
-				w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG);
-				if (dev->buf_len) {
-					*dev->buf++ = w;
-					dev->buf_len--;
-					/*
-					 * Data reg in 2430, omap3 and
-					 * 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--;
-						}
-					}
-				} else {
+				if (!dev->buf_len) {
 					if (stat & OMAP_I2C_STAT_RRDY)
 						dev_err(dev->dev,
 							"RRDY IRQ while no data"
@@ -858,6 +843,21 @@ complete:
 								" requested\n");
 					break;
 				}
+
+				w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG);
+				*dev->buf++ = w;
+				dev->buf_len--;
+				/*
+				 * Data reg in 2430, omap3 and
+				 * 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--;
+					}
+				}
 			}
 			omap_i2c_ack_stat(dev,
 				stat & (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR));
@@ -874,22 +874,7 @@ complete:
 							& 0x3F;
 			}
 			while (num_bytes--) {
-				w = 0;
-				if (dev->buf_len) {
-					w = *dev->buf++;
-					dev->buf_len--;
-					/*
-					 * Data reg in 2430, omap3 and
-					 * 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--;
-						}
-					}
-				} else {
+				if (!dev->buf_len) {
 					if (stat & OMAP_I2C_STAT_XRDY)
 						dev_err(dev->dev,
 							"XRDY IRQ while no "
@@ -901,6 +886,20 @@ complete:
 					break;
 				}
 
+				w = *dev->buf++;
+				dev->buf_len--;
+				/*
+				 * Data reg in 2430, omap3 and
+				 * 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--;
+					}
+				}
+
 				if ((dev->errata & I2C_OMAP_ERRATA_I462) &&
 				    errata_omap3_i462(dev, &stat, &err))
 					goto complete;
-- 
1.7.5.4

[PATCHv4 04/18] i2c: omap: add blank lines

From: Shubhrajyoti D <hidden>
Date: 2012-07-03 14:37:42

From: Felipe Balbi <redacted>

trivial patch to aid readability. No functional
changes.

Signed-off-by: Felipe Balbi <redacted>
Signed-off-by: Shubhrajyoti D <redacted>
---
 drivers/i2c/busses/i2c-omap.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 0da00ac..31c4e55 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -805,6 +805,7 @@ complete:
 			dev_err(dev->dev, "Arbitration lost\n");
 			err |= OMAP_I2C_STAT_AL;
 		}
+
 		/*
 		 * ProDB0017052: Clear ARDY bit twice
 		 */
@@ -817,6 +818,7 @@ complete:
 			omap_i2c_complete_cmd(dev, err);
 			return IRQ_HANDLED;
 		}
+
 		if (stat & (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR)) {
 			u8 num_bytes = 1;
 
@@ -863,6 +865,7 @@ complete:
 				stat & (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR));
 			continue;
 		}
+
 		if (stat & (OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR)) {
 			u8 num_bytes = 1;
 			if (dev->fifo_size) {
@@ -910,10 +913,12 @@ complete:
 				stat & (OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR));
 			continue;
 		}
+
 		if (stat & OMAP_I2C_STAT_ROVR) {
 			dev_err(dev->dev, "Receive overrun\n");
 			dev->cmd_err |= OMAP_I2C_STAT_ROVR;
 		}
+
 		if (stat & OMAP_I2C_STAT_XUDF) {
 			dev_err(dev->dev, "Transmit underflow\n");
 			dev->cmd_err |= OMAP_I2C_STAT_XUDF;
-- 
1.7.5.4

[PATCHv4 05/18] i2c: omap: simplify omap_i2c_ack_stat()

From: Shubhrajyoti D <hidden>
Date: 2012-07-03 14:37:43

From: Felipe Balbi <redacted>

stat & BIT(1) is the same as BIT(1), so let's
simplify things a bit by removing "stat &" from
all omap_i2c_ack_stat() calls.

Code snippet (extremely simplified):

if (stat & NACK) {
        ...
        omap_i2c_ack_stat(dev, stat & NACK);
}

if (stat & RDR) {
        ...
        omap_i2c_ack_stat(dev, stat & RDR);
}

and so on. The tricky place is only WRT errata handling, for example:

if (*stat & (NACK | AL)) {
        omap_i2c_ack_stat(dev, *stat & (XRDY | XDR));
        ...
}

but in this case, the errata says we must clear XRDY and XDR if that
errata triggers, so if they just got enabled or not, it doesn't matter.

Another tricky place is RDR | RRDY (likewise for XDR | XRDY):

if (stat & (RDR | RRDY)) {
        ...
        omap_i2c_ack_stat(dev, stat & (RDR | RRDY));
}

again here there will be no issues because those IRQs never fire
simultaneously and one will only after after we have handled the
previous, that's because the same FIFO is used anyway and we won't shift
data into FIFO until we tell the IP "hey, I'm done with the FIFO, you
can shift more data"

Signed-off-by: Felipe Balbi <redacted>
Reviewed-by : Santosh Shilimkar [off-list ref]
[Added the explaination from the discurssion to the commit logs]
Signed-off-by: Shubhrajyoti D <redacted>
---
 drivers/i2c/busses/i2c-omap.c |   19 ++++++++++---------
 1 files changed, 10 insertions(+), 9 deletions(-)
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 31c4e55..1c1ee7a 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -750,7 +750,7 @@ static int errata_omap3_i462(struct omap_i2c_dev *dev, u16 *stat, int *err)
 
 	while (--timeout && !(*stat & OMAP_I2C_STAT_XUDF)) {
 		if (*stat & (OMAP_I2C_STAT_NACK | OMAP_I2C_STAT_AL)) {
-			omap_i2c_ack_stat(dev, *stat & (OMAP_I2C_STAT_XRDY |
+			omap_i2c_ack_stat(dev, (OMAP_I2C_STAT_XRDY |
 							OMAP_I2C_STAT_XDR));
 			return -ETIMEDOUT;
 		}
@@ -811,10 +811,11 @@ complete:
 		 */
 		if (stat & (OMAP_I2C_STAT_ARDY | OMAP_I2C_STAT_NACK |
 					OMAP_I2C_STAT_AL)) {
-			omap_i2c_ack_stat(dev, stat &
-				(OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR |
-				OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR |
-				OMAP_I2C_STAT_ARDY));
+			omap_i2c_ack_stat(dev, (OMAP_I2C_STAT_RRDY |
+						OMAP_I2C_STAT_RDR |
+						OMAP_I2C_STAT_XRDY |
+						OMAP_I2C_STAT_XDR |
+						OMAP_I2C_STAT_ARDY));
 			omap_i2c_complete_cmd(dev, err);
 			return IRQ_HANDLED;
 		}
@@ -861,8 +862,8 @@ complete:
 					}
 				}
 			}
-			omap_i2c_ack_stat(dev,
-				stat & (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR));
+			omap_i2c_ack_stat(dev, (OMAP_I2C_STAT_RRDY |
+						OMAP_I2C_STAT_RDR));
 			continue;
 		}
 
@@ -909,8 +910,8 @@ complete:
 
 				omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
 			}
-			omap_i2c_ack_stat(dev,
-				stat & (OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR));
+			omap_i2c_ack_stat(dev, (OMAP_I2C_STAT_XRDY |
+						OMAP_I2C_STAT_XDR));
 			continue;
 		}
 
-- 
1.7.5.4

[PATCHv4 06/18] i2c: omap: split out [XR]DR and [XR]RDY

From: Shubhrajyoti D <hidden>
Date: 2012-07-03 14:37:44

From: Felipe Balbi <redacted>

While they do pretty much the same thing, there
are a few peculiarities. Specially WRT erratas,
it's best to split those out and re-factor the
read/write loop to another function which both
cases call.

This last part will be done on another patch.

While at that, also avoid an unncessary register
read since dev->fifo_len will always contain the
correct amount of data to be transferred.

Signed-off-by: Felipe Balbi <redacted>
Signed-off-by: Shubhrajyoti D <redacted>
---
v4: use dev->buf_len as it is in sync with the remaining
bytes avoids a reg read thereby.

 drivers/i2c/busses/i2c-omap.c |  126 ++++++++++++++++++++++++++++++-----------
 1 files changed, 92 insertions(+), 34 deletions(-)
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 1c1ee7a..5c2460d 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -820,36 +820,62 @@ complete:
 			return IRQ_HANDLED;
 		}
 
-		if (stat & (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR)) {
+		if (stat & OMAP_I2C_STAT_RDR) {
 			u8 num_bytes = 1;
 
+			if (dev->fifo_size)
+				num_bytes = dev->buf_len;
+
+			while (num_bytes--) {
+				if (!dev->buf_len) {
+					dev_err(dev->dev,
+							"RDR IRQ while no data"
+							" requested\n");
+					break;
+				}
+
+				w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG);
+				*dev->buf++ = w;
+				dev->buf_len--;
+
+				/*
+				 * Data reg in 2430, omap3 and
+				 * 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--;
+					}
+				}
+			}
+
 			if (dev->errata & I2C_OMAP_ERRATA_I207)
 				i2c_omap_errata_i207(dev, stat);
 
-			if (dev->fifo_size) {
-				if (stat & OMAP_I2C_STAT_RRDY)
-					num_bytes = dev->fifo_size;
-				else    /* read RXSTAT on RDR interrupt */
-					num_bytes = (omap_i2c_read_reg(dev,
-							OMAP_I2C_BUFSTAT_REG)
-							>> 8) & 0x3F;
-			}
+			omap_i2c_ack_stat(dev, OMAP_I2C_STAT_RDR);
+			continue;
+		}
+
+		if (stat & OMAP_I2C_STAT_RRDY) {
+			u8 num_bytes = 1;
+
+			if (dev->fifo_size)
+				num_bytes = dev->fifo_size;
+
 			while (num_bytes--) {
 				if (!dev->buf_len) {
-					if (stat & OMAP_I2C_STAT_RRDY)
-						dev_err(dev->dev,
+					dev_err(dev->dev,
 							"RRDY IRQ while no data"
-								" requested\n");
-					if (stat & OMAP_I2C_STAT_RDR)
-						dev_err(dev->dev,
-							"RDR IRQ while no data"
-								" requested\n");
+							" requested\n");
 					break;
 				}
 
 				w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG);
 				*dev->buf++ = w;
 				dev->buf_len--;
+
 				/*
 				 * Data reg in 2430, omap3 and
 				 * omap4 is 8 bit wide
@@ -862,36 +888,68 @@ complete:
 					}
 				}
 			}
-			omap_i2c_ack_stat(dev, (OMAP_I2C_STAT_RRDY |
-						OMAP_I2C_STAT_RDR));
+
+			omap_i2c_ack_stat(dev, OMAP_I2C_STAT_RRDY);
 			continue;
 		}
 
-		if (stat & (OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR)) {
+		if (stat & OMAP_I2C_STAT_XDR) {
 			u8 num_bytes = 1;
-			if (dev->fifo_size) {
-				if (stat & OMAP_I2C_STAT_XRDY)
-					num_bytes = dev->fifo_size;
-				else    /* read TXSTAT on XDR interrupt */
-					num_bytes = omap_i2c_read_reg(dev,
-							OMAP_I2C_BUFSTAT_REG)
-							& 0x3F;
+
+			if (dev->fifo_size)
+				num_bytes = dev->buf_len;
+
+			while (num_bytes--) {
+				if (!dev->buf_len) {
+					dev_err(dev->dev,
+							"XDR IRQ while no "
+							"data to send\n");
+					break;
+				}
+
+				w = *dev->buf++;
+				dev->buf_len--;
+
+				/*
+				 * Data reg in 2430, omap3 and
+				 * 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--;
+					}
+				}
+
+				if ((dev->errata & I2C_OMAP_ERRATA_I462) &&
+				    errata_omap3_i462(dev, &stat, &err))
+					goto complete;
+
+				omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
 			}
+
+			omap_i2c_ack_stat(dev, OMAP_I2C_STAT_XDR);
+			continue;
+		}
+
+		if (stat & OMAP_I2C_STAT_XRDY) {
+			u8 num_bytes = 1;
+
+			if (dev->fifo_size)
+				num_bytes = dev->fifo_size;
+
 			while (num_bytes--) {
 				if (!dev->buf_len) {
-					if (stat & OMAP_I2C_STAT_XRDY)
-						dev_err(dev->dev,
+					dev_err(dev->dev,
 							"XRDY IRQ while no "
 							"data to send\n");
-					if (stat & OMAP_I2C_STAT_XDR)
-						dev_err(dev->dev,
-							"XDR IRQ while no "
-							"data to send\n");
 					break;
 				}
 
 				w = *dev->buf++;
 				dev->buf_len--;
+
 				/*
 				 * Data reg in 2430, omap3 and
 				 * omap4 is 8 bit wide
@@ -910,8 +968,8 @@ complete:
 
 				omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
 			}
-			omap_i2c_ack_stat(dev, (OMAP_I2C_STAT_XRDY |
-						OMAP_I2C_STAT_XDR));
+
+			omap_i2c_ack_stat(dev, OMAP_I2C_STAT_XRDY);
 			continue;
 		}
 
-- 
1.7.5.4

[PATCHv4 07/18] i2c: omap: improve i462 errata handling

From: Shubhrajyoti D <hidden>
Date: 2012-07-03 14:37:45

From: Felipe Balbi <redacted>

Make it not depend on ISR's local variables
in order to make it easier to re-factor the
transmit data loop.
Also since we are waiting for XUDF just before
writing data lets not service the underflow.
This is anyways going to go once we write
the data.

Signed-off-by: Felipe Balbi <redacted>
[Avoid flagging the XUDF]
Signed-off-by: Shubhrajyoti D <redacted>
---
 drivers/i2c/busses/i2c-omap.c |   43 ++++++++++++++++++++++++++++------------
 1 files changed, 30 insertions(+), 13 deletions(-)
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 5c2460d..1715c35 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -744,27 +744,30 @@ omap_i2c_omap1_isr(int this_irq, void *dev_id)
  * data to DATA_REG. Otherwise some data bytes can be lost while transferring
  * them from the memory to the I2C interface.
  */
-static int errata_omap3_i462(struct omap_i2c_dev *dev, u16 *stat, int *err)
+static int errata_omap3_i462(struct omap_i2c_dev *dev)
 {
 	unsigned long timeout = 10000;
+	u16 stat;
 
-	while (--timeout && !(*stat & OMAP_I2C_STAT_XUDF)) {
-		if (*stat & (OMAP_I2C_STAT_NACK | OMAP_I2C_STAT_AL)) {
+	do {
+		stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
+		if (stat & OMAP_I2C_STAT_XUDF)
+			break;
+
+		if (stat & (OMAP_I2C_STAT_NACK | OMAP_I2C_STAT_AL)) {
 			omap_i2c_ack_stat(dev, (OMAP_I2C_STAT_XRDY |
 							OMAP_I2C_STAT_XDR));
-			return -ETIMEDOUT;
+			return -EIO;
 		}
 
 		cpu_relax();
-		*stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
-	}
+	} while (--timeout);
 
 	if (!timeout) {
 		dev_err(dev->dev, "timeout waiting on XUDF bit\n");
 		return 0;
 	}
 
-	*err |= OMAP_I2C_STAT_XUDF;
 	return 0;
 }
 
@@ -922,9 +925,16 @@ complete:
 					}
 				}
 
-				if ((dev->errata & I2C_OMAP_ERRATA_I462) &&
-				    errata_omap3_i462(dev, &stat, &err))
-					goto complete;
+				if (dev->errata & I2C_OMAP_ERRATA_I462) {
+					int ret;
+
+					ret = errata_omap3_i462(dev);
+					stat = omap_i2c_read_reg(dev,
+							OMAP_I2C_STAT_REG);
+
+					if (ret < 0)
+						goto complete;
+				}
 
 				omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
 			}
@@ -962,9 +972,16 @@ complete:
 					}
 				}
 
-				if ((dev->errata & I2C_OMAP_ERRATA_I462) &&
-				    errata_omap3_i462(dev, &stat, &err))
-					goto complete;
+				if (dev->errata & I2C_OMAP_ERRATA_I462) {
+					int ret;
+
+					ret = errata_omap3_i462(dev);
+					stat = omap_i2c_read_reg(dev,
+							OMAP_I2C_STAT_REG);
+
+					if (ret < 0)
+						goto complete;
+				}
 
 				omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
 			}
-- 
1.7.5.4

[PATCHv4 08/18] i2c: omap: re-factor receive/transmit data loop

From: Shubhrajyoti D <hidden>
Date: 2012-07-03 14:37:46

From: Felipe Balbi <redacted>

re-factor the common parts to a separate function,
so that code is easier to read and understand.

No functional changes.

Signed-off-by: Felipe Balbi <redacted>
Signed-off-by: Shubhrajyoti D <redacted>
---
 drivers/i2c/busses/i2c-omap.c |  204 ++++++++++++++++------------------------
 1 files changed, 82 insertions(+), 122 deletions(-)
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 1715c35..dca6d3e 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -771,12 +771,81 @@ static int errata_omap3_i462(struct omap_i2c_dev *dev)
 	return 0;
 }
 
+static void omap_i2c_receive_data(struct omap_i2c_dev *dev, u8 num_bytes,
+		bool is_rdr)
+{
+	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--;
+
+		/*
+		 * Data reg in 2430, omap3 and
+		 * 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--;
+			}
+		}
+	}
+}
+
+static int omap_i2c_transmit_data(struct omap_i2c_dev *dev, u8 num_bytes,
+		bool is_xdr)
+{
+	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--;
+
+		/*
+		 * Data reg in 2430, omap3 and
+		 * 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--;
+			}
+		}
+
+		if (dev->errata & I2C_OMAP_ERRATA_I462) {
+			int ret;
+
+			ret = errata_omap3_i462(dev);
+			if (ret < 0)
+				return ret;
+		}
+
+		omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
+	}
+
+	return 0;
+}
+
 static irqreturn_t
 omap_i2c_isr(int this_irq, void *dev_id)
 {
 	struct omap_i2c_dev *dev = dev_id;
 	u16 bits;
-	u16 stat, w;
+	u16 stat;
 	int err, count = 0;
 
 	if (pm_runtime_suspended(dev->dev))
@@ -829,30 +898,7 @@ complete:
 			if (dev->fifo_size)
 				num_bytes = dev->buf_len;
 
-			while (num_bytes--) {
-				if (!dev->buf_len) {
-					dev_err(dev->dev,
-							"RDR IRQ while no data"
-							" requested\n");
-					break;
-				}
-
-				w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG);
-				*dev->buf++ = w;
-				dev->buf_len--;
-
-				/*
-				 * Data reg in 2430, omap3 and
-				 * 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--;
-					}
-				}
-			}
+			omap_i2c_receive_data(dev, num_bytes, true);
 
 			if (dev->errata & I2C_OMAP_ERRATA_I207)
 				i2c_omap_errata_i207(dev, stat);
@@ -867,77 +913,22 @@ complete:
 			if (dev->fifo_size)
 				num_bytes = dev->fifo_size;
 
-			while (num_bytes--) {
-				if (!dev->buf_len) {
-					dev_err(dev->dev,
-							"RRDY IRQ while no data"
-							" requested\n");
-					break;
-				}
-
-				w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG);
-				*dev->buf++ = w;
-				dev->buf_len--;
-
-				/*
-				 * Data reg in 2430, omap3 and
-				 * 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--;
-					}
-				}
-			}
-
+			omap_i2c_receive_data(dev, num_bytes, false);
 			omap_i2c_ack_stat(dev, OMAP_I2C_STAT_RRDY);
 			continue;
 		}
 
 		if (stat & OMAP_I2C_STAT_XDR) {
 			u8 num_bytes = 1;
+			int ret;
 
 			if (dev->fifo_size)
 				num_bytes = dev->buf_len;
 
-			while (num_bytes--) {
-				if (!dev->buf_len) {
-					dev_err(dev->dev,
-							"XDR IRQ while no "
-							"data to send\n");
-					break;
-				}
-
-				w = *dev->buf++;
-				dev->buf_len--;
-
-				/*
-				 * Data reg in 2430, omap3 and
-				 * 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--;
-					}
-				}
-
-				if (dev->errata & I2C_OMAP_ERRATA_I462) {
-					int ret;
-
-					ret = errata_omap3_i462(dev);
-					stat = omap_i2c_read_reg(dev,
-							OMAP_I2C_STAT_REG);
-
-					if (ret < 0)
-						goto complete;
-				}
-
-				omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
-			}
+			ret = omap_i2c_transmit_data(dev, num_bytes, true);
+			stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
+			if (ret < 0)
+				goto complete;
 
 			omap_i2c_ack_stat(dev, OMAP_I2C_STAT_XDR);
 			continue;
@@ -945,46 +936,15 @@ complete:
 
 		if (stat & OMAP_I2C_STAT_XRDY) {
 			u8 num_bytes = 1;
+			int ret;
 
 			if (dev->fifo_size)
 				num_bytes = dev->fifo_size;
 
-			while (num_bytes--) {
-				if (!dev->buf_len) {
-					dev_err(dev->dev,
-							"XRDY IRQ while no "
-							"data to send\n");
-					break;
-				}
-
-				w = *dev->buf++;
-				dev->buf_len--;
-
-				/*
-				 * Data reg in 2430, omap3 and
-				 * 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--;
-					}
-				}
-
-				if (dev->errata & I2C_OMAP_ERRATA_I462) {
-					int ret;
-
-					ret = errata_omap3_i462(dev);
-					stat = omap_i2c_read_reg(dev,
-							OMAP_I2C_STAT_REG);
-
-					if (ret < 0)
-						goto complete;
-				}
-
-				omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
-			}
+			ret = omap_i2c_transmit_data(dev, num_bytes, false);
+			stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
+			if (ret < 0)
+				goto complete;
 
 			omap_i2c_ack_stat(dev, OMAP_I2C_STAT_XRDY);
 			continue;
-- 
1.7.5.4

[PATCHv4 09/18] i2c: omap: switch over to do {} while loop

From: Shubhrajyoti D <hidden>
Date: 2012-07-03 14:37:47

From: Felipe Balbi <redacted>

this will make sure that we execute at least once.
No functional changes otherwise.

Signed-off-by: Felipe Balbi <redacted>
Signed-off-by: Shubhrajyoti D <redacted>
---
 drivers/i2c/busses/i2c-omap.c |   20 ++++++++++++++------
 1 files changed, 14 insertions(+), 6 deletions(-)
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index dca6d3e..6c8f135 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -846,20 +846,28 @@ omap_i2c_isr(int this_irq, void *dev_id)
 	struct omap_i2c_dev *dev = dev_id;
 	u16 bits;
 	u16 stat;
-	int err, count = 0;
+	int err = 0, count = 0;
 
 	if (pm_runtime_suspended(dev->dev))
 		return IRQ_NONE;
 
-	bits = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
-	while ((stat = (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG))) & bits) {
+	do {
+		bits = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
+		stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
+		stat &= bits;
+
+		if (!stat) {
+			/* my work here is done */
+			return IRQ_HANDLED;
+		}
+
 		dev_dbg(dev->dev, "IRQ (ISR = 0x%04x)\n", stat);
 		if (count++ == 100) {
 			dev_warn(dev->dev, "Too much work in one IRQ\n");
-			break;
+			omap_i2c_complete_cmd(dev, err);
+			return IRQ_HANDLED;
 		}
 
-		err = 0;
 complete:
 		/*
 		 * Ack the stat in one go, but [R/X]DR and [R/X]RDY should be
@@ -959,7 +967,7 @@ complete:
 			dev_err(dev->dev, "Transmit underflow\n");
 			dev->cmd_err |= OMAP_I2C_STAT_XUDF;
 		}
-	}
+	} while (stat);
 
 	return count ? IRQ_HANDLED : IRQ_NONE;
 }
-- 
1.7.5.4

[PATCHv4 10/18] i2c: omap: ack IRQ in parts

From: Shubhrajyoti D <hidden>
Date: 2012-07-03 14:37:48

From: Felipe Balbi <redacted>

According to flow diagrams on OMAP TRMs,
we should ACK the IRQ as they happen.

Signed-off-by: Felipe Balbi <redacted>
Signed-off-by: Shubhrajyoti D <redacted>
---
 drivers/i2c/busses/i2c-omap.c |   28 ++++++++++++++++------------
 1 files changed, 16 insertions(+), 12 deletions(-)
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 6c8f135..30db822 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -869,21 +869,19 @@ omap_i2c_isr(int this_irq, void *dev_id)
 		}
 
 complete:
-		/*
-		 * Ack the stat in one go, but [R/X]DR and [R/X]RDY should be
-		 * acked after the data operation is complete.
-		 * Ref: TRM SWPU114Q Figure 18-31
-		 */
-		omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat &
-				~(OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR |
-				OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR));
-
-		if (stat & OMAP_I2C_STAT_NACK)
+		if (stat & OMAP_I2C_STAT_NACK) {
 			err |= OMAP_I2C_STAT_NACK;
+			omap_i2c_ack_stat(dev, OMAP_I2C_STAT_NACK);
+			omap_i2c_complete_cmd(dev, err);
+			return IRQ_HANDLED;
+		}
 
 		if (stat & OMAP_I2C_STAT_AL) {
 			dev_err(dev->dev, "Arbitration lost\n");
 			err |= OMAP_I2C_STAT_AL;
+			omap_i2c_ack_stat(dev, OMAP_I2C_STAT_NACK);
+			omap_i2c_complete_cmd(dev, err);
+			return IRQ_HANDLED;
 		}
 
 		/*
@@ -960,12 +958,18 @@ complete:
 
 		if (stat & OMAP_I2C_STAT_ROVR) {
 			dev_err(dev->dev, "Receive overrun\n");
-			dev->cmd_err |= OMAP_I2C_STAT_ROVR;
+			err |= OMAP_I2C_STAT_ROVR;
+			omap_i2c_ack_stat(dev, OMAP_I2C_STAT_ROVR);
+			omap_i2c_complete_cmd(dev, err);
+			return IRQ_HANDLED;
 		}
 
 		if (stat & OMAP_I2C_STAT_XUDF) {
 			dev_err(dev->dev, "Transmit underflow\n");
-			dev->cmd_err |= OMAP_I2C_STAT_XUDF;
+			err |= OMAP_I2C_STAT_XUDF;
+			omap_i2c_ack_stat(dev, OMAP_I2C_STAT_XUDF);
+			omap_i2c_complete_cmd(dev, err);
+			return IRQ_HANDLED;
 		}
 	} while (stat);
 
-- 
1.7.5.4

[PATCHv4 11/18] i2c: omap: switch to platform_get_irq()

From: Shubhrajyoti D <hidden>
Date: 2012-07-03 14:37:49

From: Felipe Balbi <redacted>

that's a nice helper from drivers core which
will give us the exact IRQ number, instead
of a pointer to an IRQ resource.

Signed-off-by: Felipe Balbi <redacted>
Signed-off-by: Shubhrajyoti D <redacted>
---
 drivers/i2c/busses/i2c-omap.c |   12 +++++++-----
 1 files changed, 7 insertions(+), 5 deletions(-)
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 30db822..46d099e 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -1012,11 +1012,12 @@ omap_i2c_probe(struct platform_device *pdev)
 {
 	struct omap_i2c_dev	*dev;
 	struct i2c_adapter	*adap;
-	struct resource		*mem, *irq;
+	struct resource		*mem;
 	struct omap_i2c_bus_platform_data *pdata = pdev->dev.platform_data;
 	struct device_node	*node = pdev->dev.of_node;
 	const struct of_device_id *match;
 	irq_handler_t isr;
+	int irq;
 	int r;
 
 	/* NOTE: driver uses the static register mapping */
@@ -1025,10 +1026,11 @@ omap_i2c_probe(struct platform_device *pdev)
 		dev_err(&pdev->dev, "no mem resource?\n");
 		return -ENODEV;
 	}
-	irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
-	if (!irq) {
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
 		dev_err(&pdev->dev, "no irq resource?\n");
-		return -ENODEV;
+		return irq;
 	}
 
 	dev = devm_kzalloc(&pdev->dev, sizeof(struct omap_i2c_dev), GFP_KERNEL);
@@ -1062,7 +1064,7 @@ omap_i2c_probe(struct platform_device *pdev)
 	}
 
 	dev->dev = &pdev->dev;
-	dev->irq = irq->start;
+	dev->irq = irq;
 
 	platform_set_drvdata(pdev, dev);
 	init_completion(&dev->cmd_complete);
-- 
1.7.5.4

[PATCHv4 12/18] i2c: omap: bus: add a receiver flag

From: Shubhrajyoti D <hidden>
Date: 2012-07-03 14:37:50

From: Felipe Balbi <redacted>

that way we can ignore TX IRQs while in receiver
mode and ignore RX IRQs while in transmitter mode.

Signed-off-by: Felipe Balbi <redacted>
[Trivial formatting changes]
Signed-off-by: Shubhrajyoti D <redacted>
---
 drivers/i2c/busses/i2c-omap.c |    8 ++++++++
 1 files changed, 8 insertions(+), 0 deletions(-)
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 46d099e..0fda3b7 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -196,6 +196,7 @@ struct omap_i2c_dev {
 						 */
 	u8			rev;
 	unsigned		b_hw:1;		/* bad h/w fixes */
+	unsigned		receiver:1;	/* true when we're in receiver mode */
 	u16			iestate;	/* Saved interrupt register */
 	u16			pscstate;
 	u16			scllstate;
@@ -512,6 +513,7 @@ 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;
 
@@ -856,6 +858,12 @@ omap_i2c_isr(int this_irq, void *dev_id)
 		stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
 		stat &= bits;
 
+		/* If we're in receiver mode, ignore XDR/XRDY */
+		if (dev->receiver)
+			stat &= ~(OMAP_I2C_STAT_XDR | OMAP_I2C_STAT_XRDY);
+		else
+			stat &= ~(OMAP_I2C_STAT_RDR | OMAP_I2C_STAT_RRDY);
+
 		if (!stat) {
 			/* my work here is done */
 			return IRQ_HANDLED;
-- 
1.7.5.4

[PATCHv4 13/18] i2c: omap: simplify errata check

From: Shubhrajyoti D <hidden>
Date: 2012-07-03 14:37:51

From: Felipe Balbi <redacted>

omap_i2c_dev is allocated with kzalloc(),
so we need not initialize b_hw to zero.

Signed-off-by: Felipe Balbi <redacted>
Signed-off-by: Shubhrajyoti D <redacted>
---
 drivers/i2c/busses/i2c-omap.c |    4 +---
 1 files changed, 1 insertions(+), 3 deletions(-)
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 0fda3b7..7e3502e 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -1114,9 +1114,7 @@ omap_i2c_probe(struct platform_device *pdev)
 
 		dev->fifo_size = (dev->fifo_size / 2);
 
-		if (dev->rev >= OMAP_I2C_REV_ON_3630_4430)
-			dev->b_hw = 0; /* Disable hardware fixes */
-		else
+		if (dev->rev < OMAP_I2C_REV_ON_3630_4430)
 			dev->b_hw = 1; /* Enable hardware fixes */
 
 		/* calculate wakeup latency constraint for MPU */
-- 
1.7.5.4

[PATCHv4 14/18] i2c: omap: always return IRQ_HANDLED

From: Shubhrajyoti D <hidden>
Date: 2012-07-03 14:37:52

From: Felipe Balbi <redacted>

otherwise we could get our IRQ line disabled due
to many spurious IRQs.

Signed-off-by: Felipe Balbi <redacted>
Signed-off-by: Shubhrajyoti D <redacted>
---
 drivers/i2c/busses/i2c-omap.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 7e3502e..81c1c1b 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -981,7 +981,7 @@ complete:
 		}
 	} while (stat);
 
-	return count ? IRQ_HANDLED : IRQ_NONE;
+	return IRQ_HANDLED;
 }
 
 static const struct i2c_algorithm omap_i2c_algo = {
-- 
1.7.5.4

[PATCHv4 15/18] i2c: omap: simplify IRQ exit path

From: Shubhrajyoti D <hidden>
Date: 2012-07-03 14:37:53

From: Felipe Balbi <redacted>

instead of having multiple return points, use
a goto statement to make that clearer.

Signed-off-by: Felipe Balbi <redacted>
Signed-off-by: Shubhrajyoti D <redacted>
---
 drivers/i2c/busses/i2c-omap.c |   20 ++++++++------------
 1 files changed, 8 insertions(+), 12 deletions(-)
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 81c1c1b..5e3fb4c 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -872,24 +872,21 @@ omap_i2c_isr(int this_irq, void *dev_id)
 		dev_dbg(dev->dev, "IRQ (ISR = 0x%04x)\n", stat);
 		if (count++ == 100) {
 			dev_warn(dev->dev, "Too much work in one IRQ\n");
-			omap_i2c_complete_cmd(dev, err);
-			return IRQ_HANDLED;
+			goto out;
 		}
 
 complete:
 		if (stat & OMAP_I2C_STAT_NACK) {
 			err |= OMAP_I2C_STAT_NACK;
 			omap_i2c_ack_stat(dev, OMAP_I2C_STAT_NACK);
-			omap_i2c_complete_cmd(dev, err);
-			return IRQ_HANDLED;
+			goto out;
 		}
 
 		if (stat & OMAP_I2C_STAT_AL) {
 			dev_err(dev->dev, "Arbitration lost\n");
 			err |= OMAP_I2C_STAT_AL;
 			omap_i2c_ack_stat(dev, OMAP_I2C_STAT_NACK);
-			omap_i2c_complete_cmd(dev, err);
-			return IRQ_HANDLED;
+			goto out;
 		}
 
 		/*
@@ -902,8 +899,7 @@ complete:
 						OMAP_I2C_STAT_XRDY |
 						OMAP_I2C_STAT_XDR |
 						OMAP_I2C_STAT_ARDY));
-			omap_i2c_complete_cmd(dev, err);
-			return IRQ_HANDLED;
+			goto out;
 		}
 
 		if (stat & OMAP_I2C_STAT_RDR) {
@@ -968,19 +964,19 @@ complete:
 			dev_err(dev->dev, "Receive overrun\n");
 			err |= OMAP_I2C_STAT_ROVR;
 			omap_i2c_ack_stat(dev, OMAP_I2C_STAT_ROVR);
-			omap_i2c_complete_cmd(dev, err);
-			return IRQ_HANDLED;
+			goto out;
 		}
 
 		if (stat & OMAP_I2C_STAT_XUDF) {
 			dev_err(dev->dev, "Transmit underflow\n");
 			err |= OMAP_I2C_STAT_XUDF;
 			omap_i2c_ack_stat(dev, OMAP_I2C_STAT_XUDF);
-			omap_i2c_complete_cmd(dev, err);
-			return IRQ_HANDLED;
+			goto out;
 		}
 	} while (stat);
 
+out:
+	omap_i2c_complete_cmd(dev, err);
 	return IRQ_HANDLED;
 }
 
-- 
1.7.5.4

[PATCHv4 16/18] i2c: omap: resize fifos before each message

From: Shubhrajyoti D <hidden>
Date: 2012-07-03 14:37:54

From: Felipe Balbi <redacted>

This patch will try to avoid the usage of
draining feature by reconfiguring the FIFO
the start condition of each message based
on the message's size.

By doing that, we will be better utilizing
the FIFO when doing big transfers.

While at that also drop the now uneeded
check for dev->buf_len as we always know
the amount of data to be transmitted.

Signed-off-by: Felipe Balbi <redacted>
Signed-off-by: Shubhrajyoti D <redacted>
---
 drivers/i2c/busses/i2c-omap.c |   83 +++++++++++++++++++++++++----------------
 1 files changed, 51 insertions(+), 32 deletions(-)
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 5e3fb4c..f64916f 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -190,6 +190,7 @@ 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
@@ -415,13 +416,6 @@ 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);
 
@@ -482,6 +476,45 @@ static int omap_i2c_bus_clear(struct omap_i2c_dev *dev)
 	return omap_i2c_wait_for_bb(dev);
 }
 
+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.
  */
@@ -498,6 +531,9 @@ 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? */
@@ -513,7 +549,6 @@ 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;
 
@@ -779,12 +814,6 @@ 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--;
@@ -794,10 +823,8 @@ 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--;
 		}
 	}
 }
@@ -808,12 +835,6 @@ 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--;
 
@@ -822,10 +843,8 @@ 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) {
@@ -920,8 +939,8 @@ 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);
@@ -948,8 +967,8 @@ 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);
-- 
1.7.5.4

[PATCHv4 17/18] i2c: omap: get rid of the "complete" label

From: Shubhrajyoti D <hidden>
Date: 2012-07-03 14:37:55

From: Felipe Balbi <redacted>

we can ack stat and complete the command from
the errata handling itself.

Signed-off-by: Felipe Balbi <redacted>
Signed-off-by: Shubhrajyoti D <redacted>
---
 drivers/i2c/busses/i2c-omap.c |   16 +++++++++++++---
 1 files changed, 13 insertions(+), 3 deletions(-)
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index f64916f..8940eb3 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -794,6 +794,17 @@ static int errata_omap3_i462(struct omap_i2c_dev *dev)
 		if (stat & (OMAP_I2C_STAT_NACK | OMAP_I2C_STAT_AL)) {
 			omap_i2c_ack_stat(dev, (OMAP_I2C_STAT_XRDY |
 							OMAP_I2C_STAT_XDR));
+			if (stat & OMAP_I2C_STAT_NACK) {
+				dev->cmd_err |= OMAP_I2C_STAT_NACK;
+				omap_i2c_ack_stat(dev, OMAP_I2C_STAT_NACK);
+			}
+
+			if (stat & OMAP_I2C_STAT_AL) {
+				dev_err(dev->dev, "Arbitration lost\n");
+				dev->cmd_err |= OMAP_I2C_STAT_AL;
+				omap_i2c_ack_stat(dev, OMAP_I2C_STAT_NACK);
+			}
+
 			return -EIO;
 		}
 
@@ -894,7 +905,6 @@ omap_i2c_isr(int this_irq, void *dev_id)
 			goto out;
 		}
 
-complete:
 		if (stat & OMAP_I2C_STAT_NACK) {
 			err |= OMAP_I2C_STAT_NACK;
 			omap_i2c_ack_stat(dev, OMAP_I2C_STAT_NACK);
@@ -957,7 +967,7 @@ complete:
 			ret = omap_i2c_transmit_data(dev, num_bytes, true);
 			stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
 			if (ret < 0)
-				goto complete;
+				goto out;
 
 			omap_i2c_ack_stat(dev, OMAP_I2C_STAT_XDR);
 			continue;
@@ -973,7 +983,7 @@ complete:
 			ret = omap_i2c_transmit_data(dev, num_bytes, false);
 			stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
 			if (ret < 0)
-				goto complete;
+				goto out;
 
 			omap_i2c_ack_stat(dev, OMAP_I2C_STAT_XRDY);
 			continue;
-- 
1.7.5.4

[PATCHv4 18/18] i2c: omap: remove redundant status read

From: Shubhrajyoti D <hidden>
Date: 2012-07-03 14:37:56

Remove the redundant read of the status register.

Signed-off-by: Shubhrajyoti D <redacted>
---
v4:Patch addition(fixes a review comment)

 drivers/i2c/busses/i2c-omap.c |    2 --
 1 files changed, 0 insertions(+), 2 deletions(-)
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 8940eb3..b1a32f8 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -965,7 +965,6 @@ omap_i2c_isr(int this_irq, void *dev_id)
 				num_bytes = dev->buf_len;
 
 			ret = omap_i2c_transmit_data(dev, num_bytes, true);
-			stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
 			if (ret < 0)
 				goto out;
 
@@ -981,7 +980,6 @@ omap_i2c_isr(int this_irq, void *dev_id)
 				num_bytes = dev->threshold;
 
 			ret = omap_i2c_transmit_data(dev, num_bytes, false);
-			stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
 			if (ret < 0)
 				goto out;
 
-- 
1.7.5.4
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