[PATCH 0/3] Blackfin I2C updates for 2.6.31

[PATCH 0/3] Blackfin I2C updates for 2.6.31

[Mike Frysinger]

Fixes for bugs in the Blackfin on-chip I2C controller.

Frank Shew (1):
  Blackfin I2C/TWI Drivers: fix bug - not work well on BF537

Michael Hennerich (1):
  Blackfin I2C/TWI Driver: make sure we don't end up with a CLKDIV=0

Sonic Zhang (1):
  Blackfin I2C TWI Driver: fix bug - REPEAT START mode doesn't repeat

 drivers/i2c/busses/Kconfig        |    2 +-
 drivers/i2c/busses/i2c-bfin-twi.c |   47 +++++++++++++++++++++++-------------
 2 files changed, 31 insertions(+), 18 deletions(-)

[PATCH 1/3] Blackfin I2C/TWI Driver: make sure we don't end up with a CLKDIV=0

[Mike Frysinger]

From: Michael Hennerich <michael.hennerich-OyLXuOCK7orQT0dZR+AlfA@public.gmane.org>

Make sure we don't end up with an invalid CLKDIV=0 in case someone
specifies 20kHz SCL or less (5 * 1024 / 20 = 0x100).

Signed-off-by: Michael Hennerich <michael.hennerich-OyLXuOCK7orQT0dZR+AlfA@public.gmane.org>
Signed-off-by: Mike Frysinger <vapier-aBrp7R+bbdUdnm+yROfE0A@public.gmane.org>
Signed-off-by: Bryan Wu <cooloney-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
---
 drivers/i2c/busses/Kconfig        |    2 +-
 drivers/i2c/busses/i2c-bfin-twi.c |   11 ++++++++---
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index f1c6ca7..c8460fa 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -298,7 +298,7 @@ config I2C_BLACKFIN_TWI
 config I2C_BLACKFIN_TWI_CLK_KHZ
 	int "Blackfin TWI I2C clock (kHz)"
 	depends on I2C_BLACKFIN_TWI
-	range 10 400
+	range 21 400
 	default 50
 	help
 	  The unit of the TWI clock is kHz.
diff --git a/drivers/i2c/busses/i2c-bfin-twi.c b/drivers/i2c/busses/i2c-bfin-twi.c
index fc548b3..3ab1f66 100644
--- a/drivers/i2c/busses/i2c-bfin-twi.c
+++ b/drivers/i2c/busses/i2c-bfin-twi.c
@@ -614,6 +614,7 @@ static int i2c_bfin_twi_probe(struct platform_device *pdev)
 	struct i2c_adapter *p_adap;
 	struct resource *res;
 	int rc;
+	unsigned int clkhilow;
 
 	iface = kzalloc(sizeof(struct bfin_twi_iface), GFP_KERNEL);
 	if (!iface) {
@@ -675,10 +676,14 @@ static int i2c_bfin_twi_probe(struct platform_device *pdev)
 	/* Set TWI internal clock as 10MHz */
 	write_CONTROL(iface, ((get_sclk() / 1024 / 1024 + 5) / 10) & 0x7F);
 
+	/*
+	 * We will not end up with a CLKDIV=0 cause no one will specifies
+	 * 20kHz SCL or less in Kconfig now. (5 * 1024 / 20 = 0x100)
+	 */
+	clkhilow = 5 * 1024 / CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ;
+
 	/* Set Twi interface clock as specified */
-	write_CLKDIV(iface, ((5*1024 / CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ)
-			<< 8) | ((5*1024 / CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ)
-			& 0xFF));
+	write_CLKDIV(iface, (clkhilow << 8) | clkhilow);
 
 	/* Enable TWI */
 	write_CONTROL(iface, read_CONTROL(iface) | TWI_ENA);
-- 
1.6.3.1

Re: [PATCH 1/3] Blackfin I2C/TWI Driver: make sure we don't end up with a CLKDIV=0

[Wolfram Sang]

[-- Attachment #1: Type: text/plain, Size: 2805 bytes --]

On Wed, May 27, 2009 at 02:20:08AM -0400, Mike Frysinger wrote:
> From: Michael Hennerich <michael.hennerich-OyLXuOCK7orQT0dZR+AlfA@public.gmane.org>
> 
> Make sure we don't end up with an invalid CLKDIV=0 in case someone
> specifies 20kHz SCL or less (5 * 1024 / 20 = 0x100).
> 
> Signed-off-by: Michael Hennerich <michael.hennerich-OyLXuOCK7orQT0dZR+AlfA@public.gmane.org>
> Signed-off-by: Mike Frysinger <vapier-aBrp7R+bbdUdnm+yROfE0A@public.gmane.org>
> Signed-off-by: Bryan Wu <cooloney-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
> ---
>  drivers/i2c/busses/Kconfig        |    2 +-
>  drivers/i2c/busses/i2c-bfin-twi.c |   11 ++++++++---
>  2 files changed, 9 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
> index f1c6ca7..c8460fa 100644
> --- a/drivers/i2c/busses/Kconfig
> +++ b/drivers/i2c/busses/Kconfig
> @@ -298,7 +298,7 @@ config I2C_BLACKFIN_TWI
>  config I2C_BLACKFIN_TWI_CLK_KHZ
>  	int "Blackfin TWI I2C clock (kHz)"
>  	depends on I2C_BLACKFIN_TWI
> -	range 10 400
> +	range 21 400
>  	default 50
>  	help
>  	  The unit of the TWI clock is kHz.
> diff --git a/drivers/i2c/busses/i2c-bfin-twi.c b/drivers/i2c/busses/i2c-bfin-twi.c
> index fc548b3..3ab1f66 100644
> --- a/drivers/i2c/busses/i2c-bfin-twi.c
> +++ b/drivers/i2c/busses/i2c-bfin-twi.c
> @@ -614,6 +614,7 @@ static int i2c_bfin_twi_probe(struct platform_device *pdev)
>  	struct i2c_adapter *p_adap;
>  	struct resource *res;
>  	int rc;
> +	unsigned int clkhilow;
>  
>  	iface = kzalloc(sizeof(struct bfin_twi_iface), GFP_KERNEL);
>  	if (!iface) {
> @@ -675,10 +676,14 @@ static int i2c_bfin_twi_probe(struct platform_device *pdev)
>  	/* Set TWI internal clock as 10MHz */
>  	write_CONTROL(iface, ((get_sclk() / 1024 / 1024 + 5) / 10) & 0x7F);
>  
> +	/*
> +	 * We will not end up with a CLKDIV=0 cause no one will specifies

specify

> +	 * 20kHz SCL or less in Kconfig now. (5 * 1024 / 20 = 0x100)
> +	 */
> +	clkhilow = 5 * 1024 / CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ;
> +
>  	/* Set Twi interface clock as specified */
> -	write_CLKDIV(iface, ((5*1024 / CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ)
> -			<< 8) | ((5*1024 / CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ)
> -			& 0xFF));
> +	write_CLKDIV(iface, (clkhilow << 8) | clkhilow);
>  
>  	/* Enable TWI */
>  	write_CONTROL(iface, read_CONTROL(iface) | TWI_ENA);
> -- 
> 1.6.3.1
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-i2c" in
> the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

-- 
Pengutronix e.K.                           | Wolfram Sang                |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |

[-- Attachment #2: Digital signature --]
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[PATCH 1/3 v2] Blackfin I2C/TWI Driver: make sure we don't end up with a CLKDIV=0

[Mike Frysinger]

From: Michael Hennerich <michael.hennerich-OyLXuOCK7orQT0dZR+AlfA@public.gmane.org>

Make sure we don't end up with an invalid CLKDIV=0 in case someone
specifies 20kHz SCL or less (5 * 1024 / 20 = 0x100).

Signed-off-by: Michael Hennerich <michael.hennerich-OyLXuOCK7orQT0dZR+AlfA@public.gmane.org>
Signed-off-by: Mike Frysinger <vapier-aBrp7R+bbdUdnm+yROfE0A@public.gmane.org>
Signed-off-by: Bryan Wu <cooloney-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
---
v2
	- fixup comment grammar pointed out by Wolfram Sang

 drivers/i2c/busses/Kconfig        |    2 +-
 drivers/i2c/busses/i2c-bfin-twi.c |   11 ++++++++---
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 7f95905..1fbfd98 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -297,7 +297,7 @@ config I2C_BLACKFIN_TWI
 config I2C_BLACKFIN_TWI_CLK_KHZ
 	int "Blackfin TWI I2C clock (kHz)"
 	depends on I2C_BLACKFIN_TWI
-	range 10 400
+	range 21 400
 	default 50
 	help
 	  The unit of the TWI clock is kHz.
diff --git a/drivers/i2c/busses/i2c-bfin-twi.c b/drivers/i2c/busses/i2c-bfin-twi.c
index 3c855ff..ea97723 100644
--- a/drivers/i2c/busses/i2c-bfin-twi.c
+++ b/drivers/i2c/busses/i2c-bfin-twi.c
@@ -614,6 +614,7 @@ static int i2c_bfin_twi_probe(struct platform_device *pdev)
 	struct i2c_adapter *p_adap;
 	struct resource *res;
 	int rc;
+	unsigned int clkhilow;
 
 	iface = kzalloc(sizeof(struct bfin_twi_iface), GFP_KERNEL);
 	if (!iface) {
@@ -676,10 +677,14 @@ static int i2c_bfin_twi_probe(struct platform_device *pdev)
 	/* Set TWI internal clock as 10MHz */
 	write_CONTROL(iface, ((get_sclk() / 1024 / 1024 + 5) / 10) & 0x7F);
 
+	/*
+	 * We will not end up with a CLKDIV=0 because no one will specify
+	 * 20kHz SCL or less in Kconfig now. (5 * 1024 / 20 = 0x100)
+	 */
+	clkhilow = 5 * 1024 / CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ;
+
 	/* Set Twi interface clock as specified */
-	write_CLKDIV(iface, ((5*1024 / CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ)
-			<< 8) | ((5*1024 / CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ)
-			& 0xFF));
+	write_CLKDIV(iface, (clkhilow << 8) | clkhilow);
 
 	/* Enable TWI */
 	write_CONTROL(iface, read_CONTROL(iface) | TWI_ENA);
-- 
1.6.3.1

[PATCH 2/3] Blackfin I2C TWI Driver: fix bug - REPEAT START mode doesn't repeat

[Mike Frysinger]

From: Sonic Zhang <sonic.zhang-OyLXuOCK7orQT0dZR+AlfA@public.gmane.org>

Avoid rewrite TWI MASTER_CTL reg when issue next message
In i2c repeat transfer mode, byte count of next message should be filled
into part of the TWI MASTER_CTL reg when interrupt MCOMP of last
message transfer is triggered. But, other bits in this reg should
not be touched.

Signed-off-by: Sonic Zhang <sonic.zhang-OyLXuOCK7orQT0dZR+AlfA@public.gmane.org>
Signed-off-by: Bryan Wu <cooloney-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
---
 drivers/i2c/busses/i2c-bfin-twi.c |   15 +++++++--------
 1 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/drivers/i2c/busses/i2c-bfin-twi.c b/drivers/i2c/busses/i2c-bfin-twi.c
index 3ab1f66..fcdb460 100644
--- a/drivers/i2c/busses/i2c-bfin-twi.c
+++ b/drivers/i2c/busses/i2c-bfin-twi.c
@@ -196,8 +196,6 @@ static void bfin_twi_handle_interrupt(struct bfin_twi_iface *iface)
 			/* remove restart bit and enable master receive */
 			write_MASTER_CTL(iface,
 				read_MASTER_CTL(iface) & ~RSTART);
-			write_MASTER_CTL(iface,
-				read_MASTER_CTL(iface) | MEN | MDIR);
 			SSYNC();
 		} else if (iface->cur_mode == TWI_I2C_MODE_REPEAT &&
 				iface->cur_msg+1 < iface->msg_num) {
@@ -222,18 +220,19 @@ static void bfin_twi_handle_interrupt(struct bfin_twi_iface *iface)
 			}
 
 			if (iface->pmsg[iface->cur_msg].len <= 255)
-				write_MASTER_CTL(iface,
-				iface->pmsg[iface->cur_msg].len << 6);
+					write_MASTER_CTL(iface,
+					(read_MASTER_CTL(iface) &
+					(~(0xff << 6))) |
+				(iface->pmsg[iface->cur_msg].len << 6));
 			else {
-				write_MASTER_CTL(iface, 0xff << 6);
+				write_MASTER_CTL(iface,
+					(read_MASTER_CTL(iface) |
+					(0xff << 6)));
 				iface->manual_stop = 1;
 			}
 			/* remove restart bit and enable master receive */
 			write_MASTER_CTL(iface,
 				read_MASTER_CTL(iface) & ~RSTART);
-			write_MASTER_CTL(iface, read_MASTER_CTL(iface) |
-				MEN | ((iface->read_write == I2C_SMBUS_READ) ?
-				MDIR : 0));
 			SSYNC();
 		} else {
 			iface->result = 1;
-- 
1.6.3.1

[PATCH 3/3] Blackfin I2C/TWI Drivers: fix bug - not work well on BF537

[Mike Frysinger]

From: Frank Shew <fshew-KZ3dJmXfLYruufBYgWm87A@public.gmane.org>

We have a custom BF537 board with an I2C RTC (MAX DS3231) running
uclinux 2007R1 for some time. Recently during migration to 2008R1.5-RC3
we losted access to the RTC. The RTC driver calls 'i2c_transfer()' which
in turns calls 'bfin_twi_master_xfer()' in i2c-bfin-twi.c.

Compared with 2007R1, it looks like the 2008R1.5 version of i2c-bin-twi.c
has a new mode 'TWI_I2C-MODE_REPEAT' which corresponds to the Repeat Start
Condition described in the HRM. However, according to the HRM, at XMIT or
RECV interrupt and when the data count is 0, not only is the RESTART bit
supposed to be set, but MDIR must also be set if the next operation is a
receive sequence, and cleared if not. Currently there is no code that looks
at the I2C_M_RD bit in the flag from the next cur_msg and set/clear the MDIR
flag accordingly at the same time that the RSTART bit is set. Instead, MDIR
is set or cleared (by OR'ing with 0?) after the RESTART bit has been cleared
during handling of MCOMP interrupt.

It appears that this is causing our failure with reading the RTC, as a
quick patch to set/clear MDIR when RESTART is set seem to solve our problem.

Signed-off-by: Frank Shew <fshew-KZ3dJmXfLYruufBYgWm87A@public.gmane.org>
Signed-off-by: Sonic Zhang <sonic.zhang-OyLXuOCK7orQT0dZR+AlfA@public.gmane.org>
Signed-off-by: Mike Frysinger <vapier-aBrp7R+bbdUdnm+yROfE0A@public.gmane.org>
Signed-off-by: Bryan Wu <cooloney-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
---
 drivers/i2c/busses/i2c-bfin-twi.c |   21 +++++++++++++++------
 1 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/drivers/i2c/busses/i2c-bfin-twi.c b/drivers/i2c/busses/i2c-bfin-twi.c
index fcdb460..f7c9793 100644
--- a/drivers/i2c/busses/i2c-bfin-twi.c
+++ b/drivers/i2c/busses/i2c-bfin-twi.c
@@ -104,9 +104,14 @@ static void bfin_twi_handle_interrupt(struct bfin_twi_iface *iface)
 			write_MASTER_CTL(iface,
 				read_MASTER_CTL(iface) | STOP);
 		else if (iface->cur_mode == TWI_I2C_MODE_REPEAT &&
-				iface->cur_msg+1 < iface->msg_num)
-			write_MASTER_CTL(iface,
-				read_MASTER_CTL(iface) | RSTART);
+		         iface->cur_msg + 1 < iface->msg_num) {
+			if (iface->pmsg[iface->cur_msg + 1].flags & I2C_M_RD)
+				write_MASTER_CTL(iface,
+					read_MASTER_CTL(iface) | RSTART | MDIR);
+			else
+				write_MASTER_CTL(iface,
+					(read_MASTER_CTL(iface) | RSTART) & ~MDIR);
+		}
 		SSYNC();
 		/* Clear status */
 		write_INT_STAT(iface, XMTSERV);
@@ -134,9 +139,13 @@ static void bfin_twi_handle_interrupt(struct bfin_twi_iface *iface)
 				read_MASTER_CTL(iface) | STOP);
 			SSYNC();
 		} else if (iface->cur_mode == TWI_I2C_MODE_REPEAT &&
-				iface->cur_msg+1 < iface->msg_num) {
-			write_MASTER_CTL(iface,
-				read_MASTER_CTL(iface) | RSTART);
+		           iface->cur_msg + 1 < iface->msg_num) {
+			if (iface->pmsg[iface->cur_msg + 1].flags & I2C_M_RD)
+				write_MASTER_CTL(iface,
+					read_MASTER_CTL(iface) | RSTART | MDIR);
+			else
+				write_MASTER_CTL(iface,
+					(read_MASTER_CTL(iface) | RSTART) & ~MDIR);
 			SSYNC();
 		}
 		/* Clear interrupt source */
-- 
1.6.3.1

Re: [PATCH 0/3] Blackfin I2C updates for 2.6.31

[Ben Dooks]

On Wed, May 27, 2009 at 02:20:07AM -0400, Mike Frysinger wrote:
> Fixes for bugs in the Blackfin on-chip I2C controller.

do you have somewhere I can pull this from (with the corrections
from review)?
 
> Frank Shew (1):
>   Blackfin I2C/TWI Drivers: fix bug - not work well on BF537
> 
> Michael Hennerich (1):
>   Blackfin I2C/TWI Driver: make sure we don't end up with a CLKDIV=0
> 
> Sonic Zhang (1):
>   Blackfin I2C TWI Driver: fix bug - REPEAT START mode doesn't repeat
> 
>  drivers/i2c/busses/Kconfig        |    2 +-
>  drivers/i2c/busses/i2c-bfin-twi.c |   47 +++++++++++++++++++++++-------------
>  2 files changed, 31 insertions(+), 18 deletions(-)
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-i2c" in
> the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

-- 
Ben (ben-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org, http://www.fluff.org/)

  'a smiley only costs 4 bytes'

Re: [Uclinux-dist-devel] [PATCH 0/3] Blackfin I2C updates for 2.6.31

[Mike Frysinger]

On Mon, Jun 1, 2009 at 18:49, Ben Dooks wrote:
> On Wed, May 27, 2009 at 02:20:07AM -0400, Mike Frysinger wrote:
>> Fixes for bugs in the Blackfin on-chip I2C controller.
>
> do you have somewhere I can pull this from (with the corrections
> from review)?

ive set up this branch with the patches:
git://git.kernel.org/pub/scm/linux/kernel/git/vapier/blackfin.git for-i2c
-mike

Re: [Uclinux-dist-devel] [PATCH 0/3] Blackfin I2C updates for 2.6.31

[Ben Dooks]

On Mon, Jun 01, 2009 at 07:37:30PM -0400, Mike Frysinger wrote:
> On Mon, Jun 1, 2009 at 18:49, Ben Dooks wrote:
> > On Wed, May 27, 2009 at 02:20:07AM -0400, Mike Frysinger wrote:
> >> Fixes for bugs in the Blackfin on-chip I2C controller.
> >
> > do you have somewhere I can pull this from (with the corrections
> > from review)?
> 
> ive set up this branch with the patches:
> git://git.kernel.org/pub/scm/linux/kernel/git/vapier/blackfin.git for-i2c
> -mike

hi, in future, shorter titles, prefixed with i2c would be nice.

changed them all to be

i2c: Blackfin TWI:

> --
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-- 
Ben (ben-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org, http://www.fluff.org/)

  'a smiley only costs 4 bytes'

Re: [Uclinux-dist-devel] [PATCH 0/3] Blackfin I2C updates for 2.6.31

[Mike Frysinger]

On Tue, Jun 2, 2009 at 18:41, Ben Dooks wrote:
> On Mon, Jun 01, 2009 at 07:37:30PM -0400, Mike Frysinger wrote:
>> On Mon, Jun 1, 2009 at 18:49, Ben Dooks wrote:
>> > On Wed, May 27, 2009 at 02:20:07AM -0400, Mike Frysinger wrote:
>> >> Fixes for bugs in the Blackfin on-chip I2C controller.
>> >
>> > do you have somewhere I can pull this from (with the corrections
>> > from review)?
>>
>> ive set up this branch with the patches:
>> git://git.kernel.org/pub/scm/linux/kernel/git/vapier/blackfin.git for-i2c
>
> hi, in future, shorter titles, prefixed with i2c would be nice.
>
> changed them all to be
>
> i2c: Blackfin TWI:

i was just using what was merged previously, but that format is fine
-mike