[PATCHv8 00/23]I2C big cleanup

[PATCHv8 00/23]I2C big cleanup

[Shubhrajyoti D]

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.
Changes since v4:
        - Ack the arbitration lost.
        - Rebase to the i2c-embedded/for-next branch.
Changes since v5:
        - Rebase to latest mainline
        - Added some more cleanup patches so as have a consolidated series.
Changes since v6:
        - Fix comments on setting the pdev to NULL.
        - Trivial changelog update
Changes since v7:
	- Remove a patch as the code is getting changed anyways
	- Changelogs update.

Previous discussions can be found here 
http://www.spinics.net/lists/linux-i2c/msg09764.html

This is the cleanup only series.
  
Tested on omap4sdp and 3430sdp.

The following changes since commit 55d512e245bc7699a8800e23df1a24195dd08217:

  Linux 3.6-rc5 (2012-09-08 16:43:45 -0700)

are available in the git repository at:
  git://gitorious.org/linus-tree/linus-tree.git for_3.7/i2c/big_cleanups


Felipe Balbi (22):
  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
  i2c: omap: always return IRQ_HANDLED
  i2c: omap: switch to threaded IRQ support
  i2c: omap: remove unnecessary pm_runtime_suspended check
  i2c: omap: switch over to autosuspend API
  i2c: omap: sanitize exit path

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

 drivers/i2c/busses/i2c-omap.c |  442 +++++++++++++++++++++++++----------------
 1 files changed, 271 insertions(+), 171 deletions(-)

-- 
1.7.5.4

[PATCHv8 01/22] i2c: omap: switch to devm_* API

[Shubhrajyoti D]

From: Felipe Balbi <balbi@ti.com>

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

Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
---
 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 5d19a49..2d9b03c 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -943,7 +943,7 @@ 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;
@@ -962,17 +962,16 @@ 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);
@@ -995,11 +994,6 @@ 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);
@@ -1057,7 +1051,8 @@ 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);
@@ -1081,7 +1076,7 @@ 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);
@@ -1090,18 +1085,12 @@ 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;
 }
@@ -1109,12 +1098,10 @@ 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))
@@ -1123,10 +1110,6 @@ 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

[PATCHv8 02/22] i2c: omap: simplify num_bytes handling

[Shubhrajyoti D]

From: Felipe Balbi <balbi@ti.com>

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 <balbi@ti.com>
Reviewed-by : Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
---
 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 2d9b03c..236cb38 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -812,8 +812,7 @@ 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;
@@ -855,8 +854,7 @@ 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

[PATCHv8 03/22] i2c: omap: decrease indentation level on data handling

[Shubhrajyoti D]

From: Felipe Balbi <balbi@ti.com>

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 <balbi@ti.com>
Reviewed-by : Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
---
 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 236cb38..0dd647a 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -813,22 +813,7 @@ 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"
@@ -839,6 +824,21 @@ 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));
@@ -855,22 +855,7 @@ 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 "
@@ -882,6 +867,20 @@ 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

[PATCHv8 04/22] i2c: omap: add blank lines

[Shubhrajyoti D]

From: Felipe Balbi <balbi@ti.com>

trivial patch to aid readability. No functional
changes.

Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
---
 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 0dd647a..30ea63c 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -786,6 +786,7 @@ complete:
 			dev_err(dev->dev, "Arbitration lost\n");
 			err |= OMAP_I2C_STAT_AL;
 		}
+
 		/*
 		 * ProDB0017052: Clear ARDY bit twice
 		 */
@@ -798,6 +799,7 @@ complete:
 			omap_i2c_complete_cmd(dev, err);
 			return IRQ_HANDLED;
 		}
+
 		if (stat & (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR)) {
 			u8 num_bytes = 1;
 
@@ -844,6 +846,7 @@ 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) {
@@ -891,10 +894,12 @@ 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

[PATCHv8 05/22] i2c: omap: simplify omap_i2c_ack_stat()

[Shubhrajyoti D]

From: Felipe Balbi <balbi@ti.com>

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 <balbi@ti.com>
Reviewed-by : Santosh Shilimkar <santosh.shilimkar@ti.com>
[Added the explaination from the discurssion to the commit logs]
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
---
 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 30ea63c..f24eae9 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -731,7 +731,7 @@ 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;
 		}
@@ -792,10 +792,11 @@ 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;
 		}
@@ -842,8 +843,8 @@ 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;
 		}
 
@@ -890,8 +891,8 @@ 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

[PATCHv8 06/22] i2c: omap: split out [XR]DR and [XR]RDY

[Shubhrajyoti D]

From: Felipe Balbi <balbi@ti.com>

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 <balbi@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
---
 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 f24eae9..815577b 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -801,36 +801,62 @@ 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
@@ -843,36 +869,68 @@ 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
@@ -891,8 +949,8 @@ 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

[PATCHv8 07/22] i2c: omap: improve i462 errata handling

[Shubhrajyoti D]

From: Felipe Balbi <balbi@ti.com>

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(Transmitter underflow) just before
writing data lets not flag the underflow.
This is anyways going to go once we write
the data.

Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
---
 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 815577b..fb57221 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -725,27 +725,30 @@ 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;
 }
 
@@ -903,9 +906,16 @@ 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);
 			}
@@ -943,9 +953,16 @@ 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

[PATCHv8 08/22] i2c: omap: re-factor receive/transmit data loop

[Shubhrajyoti D]

From: Felipe Balbi <balbi@ti.com>

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 <balbi@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
---
 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 fb57221..2c7d7cc 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -752,12 +752,81 @@ 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))
@@ -810,30 +879,7 @@ 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);
@@ -848,77 +894,22 @@ 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;
@@ -926,46 +917,15 @@ 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

[PATCHv8 09/22] i2c: omap: switch over to do {} while loop

[Shubhrajyoti D]

From: Felipe Balbi <balbi@ti.com>

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

Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
---
 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 2c7d7cc..4045134 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -827,20 +827,28 @@ 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
@@ -940,7 +948,7 @@ 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

[PATCHv8 10/22] i2c: omap: ack IRQ in parts

[Shubhrajyoti D]

From: Felipe Balbi <balbi@ti.com>

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

Signed-off-by: Felipe Balbi <balbi@ti.com>
[Ack the stat OMAP_I2C_STAT_AL in case of arbitration lost]
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
---
 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 4045134..bac1f11 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -850,21 +850,19 @@ 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_AL);
+			omap_i2c_complete_cmd(dev, err);
+			return IRQ_HANDLED;
 		}
 
 		/*
@@ -941,12 +939,18 @@ 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

[PATCHv8 11/22] i2c: omap: switch to platform_get_irq()

[Shubhrajyoti D]

From: Felipe Balbi <balbi@ti.com>

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 <balbi@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
---
 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 bac1f11..0da8169 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -993,11 +993,12 @@ 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 */
@@ -1006,10 +1007,11 @@ 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);
@@ -1043,7 +1045,7 @@ 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

[PATCHv8 12/22] i2c: omap: bus: add a receiver flag

[Shubhrajyoti D]

From: Felipe Balbi <balbi@ti.com>

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

Signed-off-by: Felipe Balbi <balbi@ti.com>
[Remove unnecessary braces]
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
---
 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 0da8169..3be147a 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -199,6 +199,7 @@ 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;
@@ -492,6 +493,7 @@ 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;
 
@@ -837,6 +839,12 @@ 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

[PATCHv8 13/22] i2c: omap: simplify errata check

[Shubhrajyoti D]

From: Felipe Balbi <balbi@ti.com>

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

Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
---
 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 3be147a..7918e48 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -1095,9 +1095,7 @@ 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

[PATCHv8 14/22] i2c: omap: always return IRQ_HANDLED

[Shubhrajyoti D]

From: Felipe Balbi <balbi@ti.com>

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

Signed-off-by: Felipe Balbi <balbi@ti.com>
[Trivial changes to commitlogs]
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
---
 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 7918e48..96fd528 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -962,7 +962,7 @@ complete:
 		}
 	} while (stat);
 
-	return count ? IRQ_HANDLED : IRQ_NONE;
+	return IRQ_HANDLED;
 }
 
 static const struct i2c_algorithm omap_i2c_algo = {
-- 
1.7.5.4

[PATCHv8 15/22] i2c: omap: simplify IRQ exit path

[Shubhrajyoti D]

From: Felipe Balbi <balbi@ti.com>

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

Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
---
 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 96fd528..4af123f 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -853,24 +853,21 @@ 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_AL);
-			omap_i2c_complete_cmd(dev, err);
-			return IRQ_HANDLED;
+			goto out;
 		}
 
 		/*
@@ -883,8 +880,7 @@ 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) {
@@ -949,19 +945,19 @@ 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

[PATCHv8 16/22] i2c: omap: resize fifos before each message

[Shubhrajyoti D]

From: Felipe Balbi <balbi@ti.com>

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 unneeded
check for dev->buf_len as we always know
the amount of data to be transmitted.

Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
---
 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 4af123f..f33bc5a 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/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 @@ 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);
-- 
1.7.5.4

[PATCHv8 17/22] i2c: omap: get rid of the "complete" label

[Shubhrajyoti D]

From: Felipe Balbi <balbi@ti.com>

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

Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
---
 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 f33bc5a..5d4bad4 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -775,6 +775,17 @@ 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;
 		}
 
@@ -875,7 +886,6 @@ 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);
@@ -938,7 +948,7 @@ 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;
@@ -954,7 +964,7 @@ 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

[PATCHv8 18/22] i2c: omap: remove redundant status read

[Shubhrajyoti D]

Currently omap_i2c_ack_stat doesn't use the stat variable.
After the read of the I2C_STAT_REG it is not used.
Remove the redundant read of the status register.

Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
---
 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 5d4bad4..498a462 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -946,7 +946,6 @@ 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;
 
@@ -962,7 +961,6 @@ 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

[PATCHv8 19/22] i2c: omap: switch to threaded IRQ support

[Shubhrajyoti D]

From: Felipe Balbi <balbi@ti.com>

for OMAP2, we can easily switch over to threaded
IRQs on the I2C driver. This will allow us to
spend less time in hardirq context.

Signed-off-by: Felipe Balbi <balbi@ti.com>
[Trivial formating changes]
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
---
 drivers/i2c/busses/i2c-omap.c |   43 +++++++++++++++++++++++++++++++++++-----
 1 files changed, 37 insertions(+), 6 deletions(-)

diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 498a462..049331c 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -176,6 +176,7 @@ enum {
 #define I2C_OMAP_ERRATA_I462		(1 << 1)
 
 struct omap_i2c_dev {
+	spinlock_t		lock;		/* IRQ synchronization */
 	struct device		*dev;
 	void __iomem		*base;		/* virtual */
 	int			irq;
@@ -854,9 +855,30 @@ static int omap_i2c_transmit_data(struct omap_i2c_dev *dev, u8 num_bytes,
 }
 
 static irqreturn_t
-omap_i2c_isr(int this_irq, void *dev_id)
+omap_i2c_isr(int irq, void *dev_id)
 {
 	struct omap_i2c_dev *dev = dev_id;
+	irqreturn_t ret = IRQ_HANDLED;
+	u16 mask;
+	u16 stat;
+
+	spin_lock(&dev->lock);
+	mask = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
+	stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
+
+	if (stat & mask)
+		ret = IRQ_WAKE_THREAD;
+
+	spin_unlock(&dev->lock);
+
+	return ret;
+}
+
+static irqreturn_t
+omap_i2c_isr_thread(int this_irq, void *dev_id)
+{
+	struct omap_i2c_dev *dev = dev_id;
+	unsigned long flags;
 	u16 bits;
 	u16 stat;
 	int err = 0, count = 0;
@@ -864,6 +886,7 @@ omap_i2c_isr(int this_irq, void *dev_id)
 	if (pm_runtime_suspended(dev->dev))
 		return IRQ_NONE;
 
+	spin_lock_irqsave(&dev->lock, flags);
 	do {
 		bits = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
 		stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
@@ -877,6 +900,7 @@ omap_i2c_isr(int this_irq, void *dev_id)
 
 		if (!stat) {
 			/* my work here is done */
+			spin_unlock_irqrestore(&dev->lock, flags);
 			return IRQ_HANDLED;
 		}
 
@@ -985,6 +1009,8 @@ omap_i2c_isr(int this_irq, void *dev_id)
 
 out:
 	omap_i2c_complete_cmd(dev, err);
+	spin_unlock_irqrestore(&dev->lock, flags);
+
 	return IRQ_HANDLED;
 }
 
@@ -1028,7 +1054,6 @@ omap_i2c_probe(struct platform_device *pdev)
 	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;
 
@@ -1078,6 +1103,8 @@ omap_i2c_probe(struct platform_device *pdev)
 	dev->dev = &pdev->dev;
 	dev->irq = irq;
 
+	spin_lock_init(&dev->lock);
+
 	platform_set_drvdata(pdev, dev);
 	init_completion(&dev->cmd_complete);
 
@@ -1130,10 +1157,14 @@ omap_i2c_probe(struct platform_device *pdev)
 	/* reset ASAP, clearing any IRQs */
 	omap_i2c_init(dev);
 
-	isr = (dev->rev < OMAP_I2C_OMAP1_REV_2) ? omap_i2c_omap1_isr :
-								   omap_i2c_isr;
-	r = devm_request_irq(&pdev->dev, dev->irq, isr, IRQF_NO_SUSPEND,
-			     pdev->name, dev);
+	if (dev->rev < OMAP_I2C_OMAP1_REV_2)
+		r = devm_request_irq(&pdev->dev, dev->irq, omap_i2c_omap1_isr,
+				IRQF_NO_SUSPEND, pdev->name, dev);
+	else
+		r = devm_request_threaded_irq(&pdev->dev, dev->irq,
+				omap_i2c_isr, omap_i2c_isr_thread,
+				IRQF_NO_SUSPEND | IRQF_ONESHOT,
+				pdev->name, dev);
 
 	if (r) {
 		dev_err(dev->dev, "failure requesting irq %i\n", dev->irq);
-- 
1.7.5.4

[PATCHv8 20/22] i2c: omap: remove unnecessary pm_runtime_suspended check

[Shubhrajyoti D]

From: Felipe Balbi <balbi@ti.com>

before starting any messages we call pm_runtime_get_sync()
which will make sure that by the time we program a transfer
and our IRQ handler gets called, we're not suspended
anymore.

Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
---
 drivers/i2c/busses/i2c-omap.c |    3 ---
 1 files changed, 0 insertions(+), 3 deletions(-)

diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 049331c..6d38a57 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -883,9 +883,6 @@ omap_i2c_isr_thread(int this_irq, void *dev_id)
 	u16 stat;
 	int err = 0, count = 0;
 
-	if (pm_runtime_suspended(dev->dev))
-		return IRQ_NONE;
-
 	spin_lock_irqsave(&dev->lock, flags);
 	do {
 		bits = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
-- 
1.7.5.4

[PATCHv8 21/22] i2c: omap: switch over to autosuspend API

[Shubhrajyoti D]

From: Felipe Balbi <balbi@ti.com>

this helps us reduce unnecessary pm transitions
in case we have another i2c message starting soon.

Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
---
 drivers/i2c/busses/i2c-omap.c |   12 ++++++++++--
 1 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 6d38a57..122f517 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -55,6 +55,9 @@
 /* timeout waiting for the controller to respond */
 #define OMAP_I2C_TIMEOUT (msecs_to_jiffies(1000))
 
+/* timeout for pm runtime autosuspend */
+#define OMAP_I2C_PM_TIMEOUT		1000	/* ms */
+
 /* For OMAP3 I2C_IV has changed to I2C_WE (wakeup enable) */
 enum {
 	OMAP_I2C_REV_REG = 0,
@@ -645,7 +648,8 @@ omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
 
 	omap_i2c_wait_for_bb(dev);
 out:
-	pm_runtime_put(dev->dev);
+	pm_runtime_mark_last_busy(dev->dev);
+	pm_runtime_put_autosuspend(dev->dev);
 	return r;
 }
 
@@ -1113,6 +1117,9 @@ omap_i2c_probe(struct platform_device *pdev)
 		dev->regs = (u8 *)reg_map_ip_v1;
 
 	pm_runtime_enable(dev->dev);
+	pm_runtime_set_autosuspend_delay(dev->dev, OMAP_I2C_PM_TIMEOUT);
+	pm_runtime_use_autosuspend(dev->dev);
+
 	r = pm_runtime_get_sync(dev->dev);
 	if (IS_ERR_VALUE(r))
 		goto err_free_mem;
@@ -1190,7 +1197,8 @@ omap_i2c_probe(struct platform_device *pdev)
 
 	of_i2c_register_devices(adap);
 
-	pm_runtime_put(dev->dev);
+	pm_runtime_mark_last_busy(dev->dev);
+	pm_runtime_put_autosuspend(dev->dev);
 
 	return 0;
 
-- 
1.7.5.4

[PATCHv8 21/22] i2c: omap: switch over to autosuspend API

[Kevin Hilman]

Shubhrajyoti D <shubhrajyoti@ti.com> writes:

> From: Felipe Balbi <balbi@ti.com>
>
> this helps us reduce unnecessary pm transitions
> in case we have another i2c message starting soon.
>
> Signed-off-by: Felipe Balbi <balbi@ti.com>
> Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>

I tracked the PM regression down to this patch.

> ---
>  drivers/i2c/busses/i2c-omap.c |   12 ++++++++++--
>  1 files changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
> index 6d38a57..122f517 100644
> --- a/drivers/i2c/busses/i2c-omap.c
> +++ b/drivers/i2c/busses/i2c-omap.c
> @@ -55,6 +55,9 @@
>  /* timeout waiting for the controller to respond */
>  #define OMAP_I2C_TIMEOUT (msecs_to_jiffies(1000))
>  
> +/* timeout for pm runtime autosuspend */
> +#define OMAP_I2C_PM_TIMEOUT		1000	/* ms */
> +
>  /* For OMAP3 I2C_IV has changed to I2C_WE (wakeup enable) */
>  enum {
>  	OMAP_I2C_REV_REG = 0,
> @@ -645,7 +648,8 @@ omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
>  
>  	omap_i2c_wait_for_bb(dev);
>  out:
> -	pm_runtime_put(dev->dev);
> +	pm_runtime_mark_last_busy(dev->dev);
> +	pm_runtime_put_autosuspend(dev->dev);

Reverting this change allows CORE to hit retention again.

I didn't debug this any further, so I'm not sure exactly why the async
suspend works but not the autosuspend.

Kevin

[PATCHv8 22/22] i2c: omap: sanitize exit path

[Shubhrajyoti D]

From: Felipe Balbi <balbi@ti.com>

move the goto out label one line down, so that
it can be used when stat is read as zero. All
other exits, can be done with a break statement.

While at that, also break out as soon as we
complete draining IRQ, since at that time
we know we transferred everything there was
to be transferred.

Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
---
 drivers/i2c/busses/i2c-omap.c |   26 +++++++++++++-------------
 1 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 122f517..b149e32 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -901,27 +901,26 @@ omap_i2c_isr_thread(int this_irq, void *dev_id)
 
 		if (!stat) {
 			/* my work here is done */
-			spin_unlock_irqrestore(&dev->lock, flags);
-			return IRQ_HANDLED;
+			goto out;
 		}
 
 		dev_dbg(dev->dev, "IRQ (ISR = 0x%04x)\n", stat);
 		if (count++ == 100) {
 			dev_warn(dev->dev, "Too much work in one IRQ\n");
-			goto out;
+			break;
 		}
 
 		if (stat & OMAP_I2C_STAT_NACK) {
 			err |= OMAP_I2C_STAT_NACK;
 			omap_i2c_ack_stat(dev, OMAP_I2C_STAT_NACK);
-			goto out;
+			break;
 		}
 
 		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_AL);
-			goto out;
+			break;
 		}
 
 		/*
@@ -934,7 +933,7 @@ omap_i2c_isr_thread(int this_irq, void *dev_id)
 						OMAP_I2C_STAT_XRDY |
 						OMAP_I2C_STAT_XDR |
 						OMAP_I2C_STAT_ARDY));
-			goto out;
+			break;
 		}
 
 		if (stat & OMAP_I2C_STAT_RDR) {
@@ -949,7 +948,7 @@ omap_i2c_isr_thread(int this_irq, void *dev_id)
 				i2c_omap_errata_i207(dev, stat);
 
 			omap_i2c_ack_stat(dev, OMAP_I2C_STAT_RDR);
-			continue;
+			break;
 		}
 
 		if (stat & OMAP_I2C_STAT_RRDY) {
@@ -972,10 +971,10 @@ omap_i2c_isr_thread(int this_irq, void *dev_id)
 
 			ret = omap_i2c_transmit_data(dev, num_bytes, true);
 			if (ret < 0)
-				goto out;
+				break;
 
 			omap_i2c_ack_stat(dev, OMAP_I2C_STAT_XDR);
-			continue;
+			break;
 		}
 
 		if (stat & OMAP_I2C_STAT_XRDY) {
@@ -987,7 +986,7 @@ omap_i2c_isr_thread(int this_irq, void *dev_id)
 
 			ret = omap_i2c_transmit_data(dev, num_bytes, false);
 			if (ret < 0)
-				goto out;
+				break;
 
 			omap_i2c_ack_stat(dev, OMAP_I2C_STAT_XRDY);
 			continue;
@@ -997,19 +996,20 @@ omap_i2c_isr_thread(int this_irq, void *dev_id)
 			dev_err(dev->dev, "Receive overrun\n");
 			err |= OMAP_I2C_STAT_ROVR;
 			omap_i2c_ack_stat(dev, OMAP_I2C_STAT_ROVR);
-			goto out;
+			break;
 		}
 
 		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);
-			goto out;
+			break;
 		}
 	} while (stat);
 
-out:
 	omap_i2c_complete_cmd(dev, err);
+
+out:
 	spin_unlock_irqrestore(&dev->lock, flags);
 
 	return IRQ_HANDLED;
-- 
1.7.5.4

[PATCHv8 00/23]I2C big cleanup

[Wolfram Sang]

On Wed, Sep 12, 2012 at 04:27:54PM +0530, Shubhrajyoti D wrote:
> 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.
> Changes since v4:
>         - Ack the arbitration lost.
>         - Rebase to the i2c-embedded/for-next branch.
> Changes since v5:
>         - Rebase to latest mainline
>         - Added some more cleanup patches so as have a consolidated series.
> Changes since v6:
>         - Fix comments on setting the pdev to NULL.
>         - Trivial changelog update
> Changes since v7:
> 	- Remove a patch as the code is getting changed anyways
> 	- Changelogs update.
> 
> Previous discussions can be found here 
> http://www.spinics.net/lists/linux-i2c/msg09764.html
> 
> This is the cleanup only series.
>   
> Tested on omap4sdp and 3430sdp.
> 
> The following changes since commit 55d512e245bc7699a8800e23df1a24195dd08217:
> 
>   Linux 3.6-rc5 (2012-09-08 16:43:45 -0700)
> 
> are available in the git repository at:
>   git://gitorious.org/linus-tree/linus-tree.git for_3.7/i2c/big_cleanups

Pushed to -next. Thanks to all involved!

-- 
Pengutronix e.K.                           | Wolfram Sang                |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
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[PATCHv8 00/23]I2C big cleanup

[Shubhrajyoti]

On Wednesday 12 September 2012 06:46 PM, Wolfram Sang wrote:
>> Tested on omap4sdp and 3430sdp.
>> > 
>> > The following changes since commit 55d512e245bc7699a8800e23df1a24195dd08217:
>> > 
>> >   Linux 3.6-rc5 (2012-09-08 16:43:45 -0700)
>> > 
>> > are available in the git repository at:
>> >   git://gitorious.org/linus-tree/linus-tree.git for_3.7/i2c/big_cleanups
> Pushed to -next. Thanks to all involved!
Thanks.

[PATCHv8 00/23]I2C big cleanup

[Kevin Hilman]

Wolfram Sang <w.sang@pengutronix.de> writes:

> On Wed, Sep 12, 2012 at 04:27:54PM +0530, Shubhrajyoti D wrote:

[...]

>> This is the cleanup only series.
>>   
>> Tested on omap4sdp and 3430sdp.
>> 
>> The following changes since commit 55d512e245bc7699a8800e23df1a24195dd08217:
>> 
>>   Linux 3.6-rc5 (2012-09-08 16:43:45 -0700)
>> 
>> are available in the git repository at:
>>   git://gitorious.org/linus-tree/linus-tree.git for_3.7/i2c/big_cleanups
>
> Pushed to -next. Thanks to all involved!

Sorry to be late to the party (again), but still catching up after some
time off.

Unfortunately, this series causes PM regressions on several OMAP
platforms.  I hope we can hold off on this until those issues are
addressed.

We *really* need to have some more thorough testing (especially PM)
before merging large series like this.

Kevin

[PATCHv8 00/23]I2C big cleanup

[Kevin Hilman]

Kevin Hilman <khilman@deeprootsystems.com> writes:

> Wolfram Sang <w.sang@pengutronix.de> writes:
>
>> On Wed, Sep 12, 2012 at 04:27:54PM +0530, Shubhrajyoti D wrote:
>
> [...]
>
>>> This is the cleanup only series.
>>>   
>>> Tested on omap4sdp and 3430sdp.
>>> 
>>> The following changes since commit 55d512e245bc7699a8800e23df1a24195dd08217:
>>> 
>>>   Linux 3.6-rc5 (2012-09-08 16:43:45 -0700)
>>> 
>>> are available in the git repository at:
>>>   git://gitorious.org/linus-tree/linus-tree.git for_3.7/i2c/big_cleanups
>>
>> Pushed to -next. Thanks to all involved!
>
> Sorry to be late to the party (again), but still catching up after some
> time off.
>
> Unfortunately, this series causes PM regressions on several OMAP
> platforms.  I hope we can hold off on this until those issues are
> addressed.

I tracked the regression down to [PATCHv8 21/22] (see reply there.)

Since this series is already merged, I suggest that the problem patch be
reverted, at least for v3.7 and until the problem is better understood
and tested.

With that patch reverted, all my PM tests are passing.  Feel free to
add:

Tested-by: Kevin Hilman <khilman@ti.com>

Kevin

[PATCHv8 00/23]I2C big cleanup

[Wolfram Sang]

Hi Kevin,

> Since this series is already merged, I suggest that the problem patch be
> reverted, at least for v3.7 and until the problem is better understood
> and tested.

I thought I'll give you guys some more days to fix the problem before
reverting.

> 
> With that patch reverted, all my PM tests are passing.  Feel free to
> add:
> 
> Tested-by: Kevin Hilman <khilman@ti.com>

Thanks. That indeed increases confidence in this series. I won't add the
tags to the tree, though, since that would mean rebasing.

All the best,

   Wolfram

-- 
Pengutronix e.K.                           | Wolfram Sang                |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
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[PATCHv8 00/23]I2C big cleanup

[Kevin Hilman]

Kevin Hilman <khilman@deeprootsystems.com> writes:

> Kevin Hilman <khilman@deeprootsystems.com> writes:
>
[...]

>> Sorry to be late to the party (again), but still catching up after some
>> time off.
>>
>> Unfortunately, this series causes PM regressions on several OMAP
>> platforms.  I hope we can hold off on this until those issues are
>> addressed.
>
> I tracked the regression down to [PATCHv8 21/22] (see reply there.)
>
> Since this series is already merged, I suggest that the problem patch be
> reverted, at least for v3.7 and until the problem is better understood
> and tested.
>
> With that patch reverted, all my PM tests are passing.  Feel free to
> add:

OK, the i2c series is off the hook.

Felipe and I spent a little time tracking this down.  Felipe suggested
that there might be a driver with periodic i2c activity keeping I2C
awake, and thus preventing CORE retention.  He was right.

On the boards where I'm seeing the failure, the RTC is firing every
second, and since the RTC is on the I2C connected PMIC, the PMIC IRQ
reads and the RTC reads are causing lots of I2C activity every second.  

With the new autosuspend feature, that is enough to keep the I2C active
continually and prevent CORE retention.

So, all that to say, from my PoV, this series can go in as is.  The PM
problem is caused by the RTC driver someplace.

Thanks Felipe,

Kevin

[PATCHv8 00/23]I2C big cleanup

[Felipe Balbi]

Hi,

On Thu, Sep 13, 2012 at 11:04:42AM -0700, Kevin Hilman wrote:
> Kevin Hilman <khilman@deeprootsystems.com> writes:
> 
> > Kevin Hilman <khilman@deeprootsystems.com> writes:
> >
> [...]
> 
> >> Sorry to be late to the party (again), but still catching up after some
> >> time off.
> >>
> >> Unfortunately, this series causes PM regressions on several OMAP
> >> platforms.  I hope we can hold off on this until those issues are
> >> addressed.
> >
> > I tracked the regression down to [PATCHv8 21/22] (see reply there.)
> >
> > Since this series is already merged, I suggest that the problem patch be
> > reverted, at least for v3.7 and until the problem is better understood
> > and tested.
> >
> > With that patch reverted, all my PM tests are passing.  Feel free to
> > add:
> 
> OK, the i2c series is off the hook.
> 
> Felipe and I spent a little time tracking this down.  Felipe suggested
> that there might be a driver with periodic i2c activity keeping I2C
> awake, and thus preventing CORE retention.  He was right.

FYI, the original idea came from Shubhro. We agreed that would be the
only way i2c would be prevented from idling.

-- 
balbi
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[PATCHv8 00/23]I2C big cleanup

[Kevin Hilman]

Felipe Balbi <balbi@ti.com> writes:

> Hi,
>
> On Thu, Sep 13, 2012 at 11:04:42AM -0700, Kevin Hilman wrote:
>> Kevin Hilman <khilman@deeprootsystems.com> writes:
>> 
>> > Kevin Hilman <khilman@deeprootsystems.com> writes:
>> >
>> [...]
>> 
>> >> Sorry to be late to the party (again), but still catching up after some
>> >> time off.
>> >>
>> >> Unfortunately, this series causes PM regressions on several OMAP
>> >> platforms.  I hope we can hold off on this until those issues are
>> >> addressed.
>> >
>> > I tracked the regression down to [PATCHv8 21/22] (see reply there.)
>> >
>> > Since this series is already merged, I suggest that the problem patch be
>> > reverted, at least for v3.7 and until the problem is better understood
>> > and tested.
>> >
>> > With that patch reverted, all my PM tests are passing.  Feel free to
>> > add:
>> 
>> OK, the i2c series is off the hook.
>> 
>> Felipe and I spent a little time tracking this down.  Felipe suggested
>> that there might be a driver with periodic i2c activity keeping I2C
>> awake, and thus preventing CORE retention.  He was right.
>
> FYI, the original idea came from Shubhro. We agreed that would be the
> only way i2c would be prevented from idling.

Great, thanks Shubhro!

Also, FYI, I just submitted a patch to the TWL RTC driver which was the
source of all the I2C activity since it's on the I2C-connected PMIC.

Thanks for the help and suggestions,

Kevin

[1] https://groups.google.com/forum/#!topic/rtc-linux/sFbYmAzCRLQ

[PATCHv8 00/23]I2C big cleanup

[Shubhrajyoti]

On Friday 14 September 2012 02:58 AM, Kevin Hilman wrote:
> Felipe Balbi <balbi@ti.com> writes:
>
>> Hi,
>>
>> On Thu, Sep 13, 2012 at 11:04:42AM -0700, Kevin Hilman wrote:
>>> Kevin Hilman <khilman@deeprootsystems.com> writes:
>>>
>>>> Kevin Hilman <khilman@deeprootsystems.com> writes:
>>>>
>>> [...]
>>>
>>>>> Sorry to be late to the party (again), but still catching up after some
>>>>> time off.
>>>>>
>>>>> Unfortunately, this series causes PM regressions on several OMAP
>>>>> platforms.  I hope we can hold off on this until those issues are
>>>>> addressed.
>>>> I tracked the regression down to [PATCHv8 21/22] (see reply there.)
>>>>
>>>> Since this series is already merged, I suggest that the problem patch be
>>>> reverted, at least for v3.7 and until the problem is better understood
>>>> and tested.
>>>>
>>>> With that patch reverted, all my PM tests are passing.  Feel free to
>>>> add:
>>> OK, the i2c series is off the hook.
>>>
>>> Felipe and I spent a little time tracking this down.  Felipe suggested
>>> that there might be a driver with periodic i2c activity keeping I2C
>>> awake, and thus preventing CORE retention.  He was right.
>> FYI, the original idea came from Shubhro. We agreed that would be the
>> only way i2c would be prevented from idling.
> Great, thanks Shubhro!
>
> Also, FYI, I just submitted a patch to the TWL RTC driver which was the
> source of all the I2C activity since it's on the I2C-connected PMIC.
>
> Thanks for the help and suggestions,
>
> Kevin
>
> [1] https://groups.google.com/forum/#!topic/rtc-linux/sFbYmAzCRLQ
Thanks for the testing and the patch.

[PATCHv8 00/23]I2C big cleanup

[Kevin Hilman]

Shubhrajyoti D <shubhrajyoti@ti.com> writes:

[...]

>
> This is the cleanup only series.
>   
> Tested on omap4sdp and 3430sdp.

It would be extremely helpful if you would describe how this was tested.
And for me, it would be a source of extreme joy if you described any PM
testing.

I gave this some additional PM testing on 3430/n900, 3530/Overo,
3730/OveroSTORM, 3730/Beagle-xM and 4430/Panda.

I tested v3.6-rc5 which passed all PM tests and then added this series
(by merging the i2c-embedded/i2c-next branch.)  PM tests then fail.

At least on 3530/Overo and 3730/Overo, CORE no longer hits retenion (or
off) during idle.  

The easy way to notice this is to see that even when no i2c transactions
are happening, the runtime PM status for omap_i2c.1 is remains 'active':

# cat omap_i2c.*/power/runtime_status 
active
suspended

Of course that means that clocks are never gated during idle, and CORE
will never hit retention.

I noticed it because my PM tests detected that the CORE powerdomain was
not transitioning to retention (or off) during idle.

To reproduce, simply enable UART timeouts so CORE will hit retention:

echo 3000 > /sys/devices/platform/omap_uart.0/power/autosuspend_delay_ms
echo 3000 > /sys/devices/platform/omap_uart.1/power/autosuspend_delay_ms
echo 3000 > /sys/devices/platform/omap_uart.2/power/autosuspend_delay_ms
echo 3000 > /sys/devices/platform/omap_uart.3/power/autosuspend_delay_ms

and check the core_pwrm state counters:

cat /debug/pm_debug/count

wait > 3 seconds for the UART autosuspend timers to kick in.  At this
point, CORE should be transitioning to retenion in idle (determined by
noticing that the RET counter for core_pwrdm is increasing.)

With $SUBJECT series applied, you'll notice that CORE is not
transitioning.

Kevin

> The following changes since commit 55d512e245bc7699a8800e23df1a24195dd08217:
>
>   Linux 3.6-rc5 (2012-09-08 16:43:45 -0700)
>
> are available in the git repository at:
>   git://gitorious.org/linus-tree/linus-tree.git for_3.7/i2c/big_cleanups
>
>
> Felipe Balbi (22):
>   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
>   i2c: omap: always return IRQ_HANDLED
>   i2c: omap: switch to threaded IRQ support
>   i2c: omap: remove unnecessary pm_runtime_suspended check
>   i2c: omap: switch over to autosuspend API
>   i2c: omap: sanitize exit path
>
> Shubhrajyoti D (1):
>   i2c: omap: remove redundant status read
>
>  drivers/i2c/busses/i2c-omap.c |  442 +++++++++++++++++++++++++----------------
>  1 files changed, 271 insertions(+), 171 deletions(-)

[PATCHv8 00/23]I2C big cleanup

[Felipe Balbi]

On Wed, Sep 12, 2012 at 03:27:22PM -0700, Kevin Hilman wrote:
> Shubhrajyoti D <shubhrajyoti@ti.com> writes:
> 
> [...]
> 
> >
> > This is the cleanup only series.
> >   
> > Tested on omap4sdp and 3430sdp.
> 
> It would be extremely helpful if you would describe how this was tested.
> And for me, it would be a source of extreme joy if you described any PM
> testing.
> 
> I gave this some additional PM testing on 3430/n900, 3530/Overo,
> 3730/OveroSTORM, 3730/Beagle-xM and 4430/Panda.
> 
> I tested v3.6-rc5 which passed all PM tests and then added this series
> (by merging the i2c-embedded/i2c-next branch.)  PM tests then fail.
> 
> At least on 3530/Overo and 3730/Overo, CORE no longer hits retenion (or
> off) during idle.  
> 
> The easy way to notice this is to see that even when no i2c transactions
> are happening, the runtime PM status for omap_i2c.1 is remains 'active':
> 
> # cat omap_i2c.*/power/runtime_status 
> active
> suspended
> 
> Of course that means that clocks are never gated during idle, and CORE
> will never hit retention.
> 
> I noticed it because my PM tests detected that the CORE powerdomain was
> not transitioning to retention (or off) during idle.
> 
> To reproduce, simply enable UART timeouts so CORE will hit retention:
> 
> echo 3000 > /sys/devices/platform/omap_uart.0/power/autosuspend_delay_ms
> echo 3000 > /sys/devices/platform/omap_uart.1/power/autosuspend_delay_ms
> echo 3000 > /sys/devices/platform/omap_uart.2/power/autosuspend_delay_ms
> echo 3000 > /sys/devices/platform/omap_uart.3/power/autosuspend_delay_ms
> 
> and check the core_pwrm state counters:
> 
> cat /debug/pm_debug/count
> 
> wait > 3 seconds for the UART autosuspend timers to kick in.  At this
> point, CORE should be transitioning to retenion in idle (determined by
> noticing that the RET counter for core_pwrdm is increasing.)

I just ran same tests on pandaboard and i2c is suspended actually,
though no power domain transitions to RET. Do we not have retention
while idle on pandaboard ?

See below for a few results... First I ran this script to set everything
up:

#!/bin/sh

echo "mounting proc"
mount -t proc none /proc

echo "mounting sysfs"
mount -t sysfs none /sys

echo "mounting debugfs"
mount -t debugfs none /debug

echo "UART autosuspend delay"
echo 3000 > /sys/devices/platform/omap_uart.0/power/autosuspend_delay_ms
echo 3000 > /sys/devices/platform/omap_uart.1/power/autosuspend_delay_ms
echo 3000 > /sys/devices/platform/omap_uart.2/power/autosuspend_delay_ms
echo 3000 > /sys/devices/platform/omap_uart.3/power/autosuspend_delay_ms

echo "check omap_i2c.* status"
cat /sys/devices/platform/omap_i2c.*/power/runtime_status

echo "check CORE pm counters"
grep "^core_pwrdm" /debug/pm_debug/count

Then I triggered a few i2c transfers by reading regulator status through
sysfs:

# cat /sys/class/regulator/regulator.*/status
[  507.469299] omap_i2c omap_i2c.1: omap_i2c_runtime_resume
normal
normal
off
off
normal
normal
normal
normal
normal
off
# [  509.010711] omap_i2c omap_i2c.1: omap_i2c_runtime_suspend
cat /sys/devices/platform/omap_i2c.*/power/runtime_status
suspended
suspended
suspended
suspended

notice the prints I've added... I don't know what could go wrong only on
Overo that i2c doesn't suspend. Can you add this debugging patch just
for me to see if, at least, omap_i2c_runtime_suspend is being called ?

diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index c78431a..ac61664 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -1238,6 +1238,8 @@ static int omap_i2c_runtime_suspend(struct device *dev)
 	struct omap_i2c_dev *_dev = platform_get_drvdata(pdev);
 	u16 iv;
 
+	dev_info(dev, "%s\n", __func__);
+
 	_dev->iestate = omap_i2c_read_reg(_dev, OMAP_I2C_IE_REG);
 
 	omap_i2c_write_reg(_dev, OMAP_I2C_IE_REG, 0);
@@ -1277,6 +1279,8 @@ static int omap_i2c_runtime_resume(struct device *dev)
 	if (_dev->iestate)
 		omap_i2c_write_reg(_dev, OMAP_I2C_IE_REG, _dev->iestate);
 
+	dev_info(dev, "%s\n", __func__);
+
 	return 0;
 }
 #endif /* CONFIG_PM_RUNTIME */

this is on top of Wolfram's for-next branch, btw. Maybe you should also
add:

CONFIG_I2C_DEBUG_CORE=y
CONFIG_I2C_DEBUG_ALGO=y
CONFIG_I2C_DEBUG_BUS=y

to your .config just in case.

cheers

-- 
balbi
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[PATCHv8 00/23]I2C big cleanup

[Kevin Hilman]

Felipe Balbi <balbi@ti.com> writes:

[...]

> I just ran same tests on pandaboard and i2c is suspended actually,
> though no power domain transitions to RET. Do we not have retention
> while idle on pandaboard ?

Not for CORE.  Only CPUx and MPU domains will be transitioning on OMAP4,
and then, only with CPUidle enabled.

Until we have CORE retention support in mainline (we're almost there)
OMAP4 is not a useful test platform for device PM.

Kevin

[PATCHv8 00/23]I2C big cleanup

[Shubhrajyoti]

On Thursday 13 September 2012 03:57 AM, Kevin Hilman wrote:
> Shubhrajyoti D <shubhrajyoti@ti.com> writes:
>
> [...]
>
>> This is the cleanup only series.
>>   
>> Tested on omap4sdp and 3430sdp.
> It would be extremely helpful if you would describe how this was tested.
> And for me, it would be a source of extreme joy if you described any PM
> testing.
>
> I gave this some additional PM testing on 3430/n900, 3530/Overo,
> 3730/OveroSTORM, 3730/Beagle-xM and 4430/Panda.
>
> I tested v3.6-rc5 which passed all PM tests and then added this series
> (by merging the i2c-embedded/i2c-next branch.)  PM tests then fail.
>
> At least on 3530/Overo and 3730/Overo, CORE no longer hits retenion (or
> off) during idle.  
>
> The easy way to notice this is to see that even when no i2c transactions
> are happening, the runtime PM status for omap_i2c.1 is remains 'active':
>
> # cat omap_i2c.*/power/runtime_status 
> active
> suspended
>
> Of course that means that clocks are never gated during idle, and CORE
> will never hit retention.
>
> I noticed it because my PM tests detected that the CORE powerdomain was
> not transitioning to retention (or off) during idle.
>
> To reproduce, simply enable UART timeouts so CORE will hit retention:
>
> echo 3000 > /sys/devices/platform/omap_uart.0/power/autosuspend_delay_ms
> echo 3000 > /sys/devices/platform/omap_uart.1/power/autosuspend_delay_ms
> echo 3000 > /sys/devices/platform/omap_uart.2/power/autosuspend_delay_ms
> echo 3000 > /sys/devices/platform/omap_uart.3/power/autosuspend_delay_ms
>
> and check the core_pwrm state counters:
>
> cat /debug/pm_debug/count
>
> wait > 3 seconds for the UART autosuspend timers to kick in.  At this
> point, CORE should be transitioning to retenion in idle (determined by
> noticing that the RET counter for core_pwrdm is increasing.)
>
> With $SUBJECT series applied, you'll notice that CORE is not
> transitioning.
However I do not see the issue,let me know if I missed something see below.

On my 3430sdp

/sys/bus/platform/devices # cat omap_i2c.*/power/runtime_status
suspended
suspended
suspended
/sys/bus/platform/devices #
/sys/bus/platform/devices # cat omap_i2c.*/power/autosuspend_delay_ms
1000
1000
1000
/sys/bus/platform/devices # echo 3000 >
/sys/devices/platform/omap_uart.0/power/
autosuspend_delay_ms
/sys/bus/platform/devices # echo 3000 >
/sys/devices/platform/omap_uart.1/power/
autosuspend_delay_ms
/sys/bus/platform/devices # echo 3000 >
/sys/devices/platform/omap_uart.2/power/
autosuspend_delay_ms
/sys/bus/platform/devices #
/sys/bus/platform/devices # cat /debug/pm_debug/count
usbhost_pwrdm
(ON),OFF:0,RET:1373,INA:0,ON:1374,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0
sgx_pwrdm (OFF),OFF:1,RET:0,INA:0,ON:1,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0
core_pwrdm
(ON),OFF:0,RET:1,INA:0,ON:2,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0,RET-MEMBANK2-OFF:0
per_pwrdm (ON),OFF:0,RET:79,INA:0,ON:80,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0
dss_pwrdm
(ON),OFF:0,RET:1373,INA:0,ON:1374,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0
cam_pwrdm (RET),OFF:0,RET:1,INA:0,ON:1,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0
neon_pwrdm (ON),OFF:0,RET:1373,INA:0,ON:1374,RET-LOGIC-OFF:0
mpu_pwrdm
(ON),OFF:0,RET:1373,INA:0,ON:1374,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0
iva2_pwrdm
(RET),OFF:0,RET:1,INA:0,ON:1,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0,RET-MEMBANK2-OFF:0,RET-MEMBANK3-OFF:0,RE0
usbhost_clkdm->usbhost_pwrdm (1)
sgx_clkdm->sgx_pwrdm (0)
per_clkdm->per_pwrdm (13)
cam_clkdm->cam_pwrdm (0)
dss_clkdm->dss_pwrdm (1)
d2d_clkdm->core_pwrdm (0)
iva2_clkdm->iva2_pwrdm (0)
mpu_clkdm->mpu_pwrdm (0)
core_l4_clkdm->core_pwrdm (23)
core_l3_clkdm->core_pwrdm (4)
neon_clkdm->neon_pwrdm (0)
/sys/bus/platform/devices #
/sys/bus/platform/devices #
/sys/bus/platform/devices # sleep 5
/sys/bus/platform/devices # cat /debug/pm_debug/count
usbhost_pwrdm
(ON),OFF:0,RET:1512,INA:0,ON:1513,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0
sgx_pwrdm (OFF),OFF:1,RET:0,INA:0,ON:1,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0
core_pwrdm
(ON),OFF:0,RET:12,INA:0,ON:13,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0,RET-MEMBANK2-OFF:0
per_pwrdm (ON),OFF:0,RET:218,INA:0,ON:219,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0
dss_pwrdm
(ON),OFF:0,RET:1512,INA:0,ON:1513,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0
cam_pwrdm (RET),OFF:0,RET:1,INA:0,ON:1,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0
neon_pwrdm (ON),OFF:0,RET:1512,INA:0,ON:1513,RET-LOGIC-OFF:0
mpu_pwrdm
(ON),OFF:0,RET:1512,INA:0,ON:1513,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0
iva2_pwrdm
(RET),OFF:0,RET:1,INA:0,ON:1,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0,RET-MEMBANK2-OFF:0,RET-MEMBANK3-OFF:0,RE0
usbhost_clkdm->usbhost_pwrdm (1)
sgx_clkdm->sgx_pwrdm (0)
per_clkdm->per_pwrdm (13)
cam_clkdm->cam_pwrdm (0)
dss_clkdm->dss_pwrdm (1)
d2d_clkdm->core_pwrdm (0)
iva2_clkdm->iva2_pwrdm (0)
mpu_clkdm->mpu_pwrdm (0)
core_l4_clkdm->core_pwrdm (23)
core_l3_clkdm->core_pwrdm (4)
neon_clkdm->neon_pwrdm (0)
/sys/bus/platform/devices # cat omap_i2c.*/power/runtime_status
suspended
suspended
suspended
/sys/bus/platform/devices #


>
> Kevin
>
>> The following changes since commit 55d512e245bc7699a8800e23df1a24195dd08217:
>>
>>   Linux 3.6-rc5 (2012-09-08 16:43:45 -0700)
>>
>> are available in the git repository at:
>>   git://gitorious.org/linus-tree/linus-tree.git for_3.7/i2c/big_cleanups
>>
>>
>> Felipe Balbi (22):
>>   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
>>   i2c: omap: always return IRQ_HANDLED
>>   i2c: omap: switch to threaded IRQ support
>>   i2c: omap: remove unnecessary pm_runtime_suspended check
>>   i2c: omap: switch over to autosuspend API
>>   i2c: omap: sanitize exit path
>>
>> Shubhrajyoti D (1):
>>   i2c: omap: remove redundant status read
>>
>>  drivers/i2c/busses/i2c-omap.c |  442 +++++++++++++++++++++++++----------------
>>  1 files changed, 271 insertions(+), 171 deletions(-)

[PATCHv8 00/23]I2C big cleanup

[Felipe Balbi]

Hi,

On Thu, Sep 13, 2012 at 11:34:48AM +0530, Shubhrajyoti wrote:
> On Thursday 13 September 2012 03:57 AM, Kevin Hilman wrote:
> > Shubhrajyoti D <shubhrajyoti@ti.com> writes:
> >
> > [...]
> >
> >> This is the cleanup only series.
> >>   
> >> Tested on omap4sdp and 3430sdp.
> > It would be extremely helpful if you would describe how this was tested.
> > And for me, it would be a source of extreme joy if you described any PM
> > testing.
> >
> > I gave this some additional PM testing on 3430/n900, 3530/Overo,
> > 3730/OveroSTORM, 3730/Beagle-xM and 4430/Panda.
> >
> > I tested v3.6-rc5 which passed all PM tests and then added this series
> > (by merging the i2c-embedded/i2c-next branch.)  PM tests then fail.
> >
> > At least on 3530/Overo and 3730/Overo, CORE no longer hits retenion (or
> > off) during idle.  
> >
> > The easy way to notice this is to see that even when no i2c transactions
> > are happening, the runtime PM status for omap_i2c.1 is remains 'active':
> >
> > # cat omap_i2c.*/power/runtime_status 
> > active
> > suspended
> >
> > Of course that means that clocks are never gated during idle, and CORE
> > will never hit retention.
> >
> > I noticed it because my PM tests detected that the CORE powerdomain was
> > not transitioning to retention (or off) during idle.
> >
> > To reproduce, simply enable UART timeouts so CORE will hit retention:
> >
> > echo 3000 > /sys/devices/platform/omap_uart.0/power/autosuspend_delay_ms
> > echo 3000 > /sys/devices/platform/omap_uart.1/power/autosuspend_delay_ms
> > echo 3000 > /sys/devices/platform/omap_uart.2/power/autosuspend_delay_ms
> > echo 3000 > /sys/devices/platform/omap_uart.3/power/autosuspend_delay_ms
> >
> > and check the core_pwrm state counters:
> >
> > cat /debug/pm_debug/count
> >
> > wait > 3 seconds for the UART autosuspend timers to kick in.  At this
> > point, CORE should be transitioning to retenion in idle (determined by
> > noticing that the RET counter for core_pwrdm is increasing.)
> >
> > With $SUBJECT series applied, you'll notice that CORE is not
> > transitioning.
> However I do not see the issue,let me know if I missed something see below.
> 
> On my 3430sdp
> 
> /sys/bus/platform/devices # cat omap_i2c.*/power/runtime_status
> suspended
> suspended
> suspended
> /sys/bus/platform/devices #
> /sys/bus/platform/devices # cat omap_i2c.*/power/autosuspend_delay_ms
> 1000
> 1000
> 1000

I just revived my very, very old 3503 overo and while i2c isn't active,
I don't see transitions on core power domain:

# mount -t proc none /proc
# mount -t sysfs none /sys
# mount -t debugfs none /debug
# echo 3000 > /sys/devices/platform/omap_uart.0/power/autosuspend_delay_ms
# echo 3000 > /sys/devices/platform/omap_uart.1/power/autosuspend_delay_ms
# echo 3000 > /sys/devices/platform/omap_uart.2/power/autosuspend_delay_ms
# cat /sys/devices/platform/omap_i2c.*/power/runtime_status
suspended
suspended
# grep ^core_pwrdm /debug/pm_debug/count && sleep 5 && grep ^core_pwrdm /debug/pm_debug/count
core_pwrdm (ON),OFF:0,RET:0,INA:0,ON:1,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0,RET-MEMBANK2-OFF:0
core_pwrdm (ON),OFF:0,RET:0,INA:0,ON:1,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0,RET-MEMBANK2-OFF:0

Weird, but I don't think i2c is to blame here (unless I'm missing
something). I can see that after i2c transfers, my suspend function is
called and right after that i2c is suspended:

# cat /sys/class/regulator/regulator.*/status && sleep 1 && cat /sys/devices/platform/omap_i2c.*/power/runtime_status
[  411.072998] omap_i2c omap_i2c.1: omap_i2c_runtime_resume
normal
normal
normal
[  412.075347] omap_i2c omap_i2c.1: omap_i2c_runtime_suspend
suspended
suspended

What am I missing to get any pm transitions to happen with my overo ?

# cat  /debug/pm_debug/count && sleep 5 && cat /debug/pm_debug/count
usbhost_pwrdm (ON),OFF:0,RET:0,INA:0,ON:1,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0
sgx_pwrdm (OFF),OFF:1,RET:0,INA:0,ON:0,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0
core_pwrdm (ON),OFF:0,RET:0,INA:0,ON:1,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0,RET-MEMBANK2-OFF:0
per_pwrdm (ON),OFF:0,RET:0,INA:0,ON:1,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0
dss_pwrdm (ON),OFF:0,RET:0,INA:0,ON:1,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0
cam_pwrdm (RET),OFF:0,RET:1,INA:0,ON:1,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0
neon_pwrdm (ON),OFF:0,RET:2379,INA:0,ON:2380,RET-LOGIC-OFF:0
mpu_pwrdm (ON),OFF:0,RET:2377,INA:0,ON:2378,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0
iva2_pwrdm (ON),OFF:0,RET:0,INA:0,ON:1,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0,RET-MEMBANK2-OFF:0,RET-MEMBANK3-OFF:0,RET-MEMBANK4-OFF:0
usbhost_clkdm->usbhost_pwrdm (1)
sgx_clkdm->sgx_pwrdm (0)
per_clkdm->per_pwrdm (19)
cam_clkdm->cam_pwrdm (0)
dss_clkdm->dss_pwrdm (1)
d2d_clkdm->core_pwrdm (0)
iva2_clkdm->iva2_pwrdm (0)
mpu_clkdm->mpu_pwrdm (0)
core_l4_clkdm->core_pwrdm (21)
core_l3_clkdm->core_pwrdm (4)
neon_clkdm->neon_pwrdm (0)
usbhost_pwrdm (ON),OFF:0,RET:0,INA:0,ON:1,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0
sgx_pwrdm (OFF),OFF:1,RET:0,INA:0,ON:0,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0
core_pwrdm (ON),OFF:0,RET:0,INA:0,ON:1,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0,RET-MEMBANK2-OFF:0
per_pwrdm (ON),OFF:0,RET:0,INA:0,ON:1,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0
dss_pwrdm (ON),OFF:0,RET:0,INA:0,ON:1,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0
cam_pwrdm (RET),OFF:0,RET:1,INA:0,ON:1,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0
neon_pwrdm (ON),OFF:0,RET:2442,INA:0,ON:2443,RET-LOGIC-OFF:0
mpu_pwrdm (ON),OFF:0,RET:2440,INA:0,ON:2441,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0
iva2_pwrdm (ON),OFF:0,RET:0,INA:0,ON:1,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0,RET-MEMBANK2-OFF:0,RET-MEMBANK3-OFF:0,RET-MEMBANK4-OFF:0
usbhost_clkdm->usbhost_pwrdm (1)
sgx_clkdm->sgx_pwrdm (0)
per_clkdm->per_pwrdm (19)
cam_clkdm->cam_pwrdm (0)
dss_clkdm->dss_pwrdm (1)
d2d_clkdm->core_pwrdm (0)
iva2_clkdm->iva2_pwrdm (0)
mpu_clkdm->mpu_pwrdm (0)
core_l4_clkdm->core_pwrdm (21)
core_l3_clkdm->core_pwrdm (4)
neon_clkdm->neon_pwrdm (0)

-- 
balbi
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[PATCHv8 00/23]I2C big cleanup

[Shubhrajyoti]

On Thursday 13 September 2012 11:34 AM, Shubhrajyoti wrote:
> > At least on 3530/Overo and 3730/Overo, CORE no longer hits retenion (or
> > off) during idle.  
I dont have an Overo, anyways will see if I can get one

However on beagleXm even off count increases

/ # grep "^core_pwrdm" /debug/pm_debug/count
core_pwrdm
(ON),OFF:48,RET:856,INA:0,ON:905,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0,RET-MEMBANK2-OFF:0
/ # cat /sys/devices/platform/omap_i2c.*/power/runtime_status
suspended
suspended
/ #
/ #
/ # cat /sys/devices/platform/omap_i2c.*/power/autosuspend_delay_ms
1000
1000
/ #
/ #
/ # grep "^core_pwrdm" /debug/pm_debug/count
core_pwrdm
(ON),OFF:218,RET:856,INA:0,ON:1075,RET-LOGIC-OFF:0,RET-MEMBANK1-OFF:0,RET-MEMBANK2-OFF:0
/ #