Re: [PATCH 1/5] ARM: shmobile: kzm9g legacy: Set i2c clks_per_count to 2
On Wed, Nov 12, 2014 at 9:53 AM, Geert Uytterhoeven
ge...@linux-m68k.org wrote:
i2c_shmobile support.) in v2.6.37.
Without this fix i2c may not operate correctly on the sh73a0/kzm9g.
Thanks, that's correct.
git tag --contains b028f94b76319e1b8 says v2.6.38.
Not that you're gonna backport it to ltsi-v2.6.37 ;-)
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say programmer or something like that.
-- Linus Torvalds
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Re: [PATCH 1/5] ARM: shmobile: kzm9g legacy: Set i2c clks_per_count to 2
Hi Simon,
On Wed, Nov 12, 2014 at 2:44 AM, Simon Horman ho...@verge.net.au wrote:
On Fri, Nov 07, 2014 at 06:24:21AM +0100, Wolfram Sang wrote:
On Thu, Nov 06, 2014 at 12:52:06PM +0100, Geert Uytterhoeven wrote:
On sh73a0/kzm9g-legacy, probing of the i2c masters fails with:
i2c-sh_mobile i2c-sh_mobile.0: timing values out of range:
L/H=0x208/0x1bf
sh_mobile: probe of i2c-sh_mobile.0 failed with error -22
Yay, so the warning I added found another bug \o/
According to the datasheet, the transfer rate is derived from the HP
clock (which runs at 104 MHz) divided by two. Hence
i2c_sh_mobile_platform_data.clks_per_count should be set to two.
Now probing succeeds, and i2c works:
i2c-sh_mobile i2c-sh_mobile.0: I2C adapter 0 with bus speed 10 Hz
(L/H=0x104/0xe0)
Signed-off-by: Geert Uytterhoeven geert+rene...@glider.be
Reviewed-by: Wolfram Sang wsa+rene...@sang-engineering.com
As this appears to be a bug fix I would like to accompany this patch with
some text describing when the problem was introduced and what its effects
are. In short a rough guide to if it should be applied to -stable. To that
end I prepared the following which I would appreciate your feedback on.
* ARM: shmobile: kzm9g legacy: Set i2c clks_per_count
This problem appears to have been introduced when i2c shmobile support was
added to the sh73a9 by b028f94b76319e1b8 (ARM: mach-shmobile: sh73a0
sh73a0
i2c_shmobile support.) in v2.6.37.
Without this fix i2c may not operate correctly on the sh73a0/kzm9g.
Thanks, that's correct.
BTW, I guess Kuribayashi-san was aware of the problem:
commit ebd5ac165f2aaefb767c53112c2010b0ff3df688
Author: Shinya Kuribayashi shinya.kuribayashi...@renesas.com
Date: Wed Oct 24 19:58:10 2012 +0900
i2c: i2c-sh_mobile: support I2C hardware block with a faster operating clock
On newer SH-/R-Mobile SoCs, a clock supply to the I2C hardware block,
which is used to generate the SCL clock output, is getting faster than
before, while on the other hand, the SCL clock control registers, ICCH
and ICCL, stay unchanged in 9-bit-wide (8+1).
On such silicons, the internal SCL clock counter gets incremented every
2 clocks of the operating clock.
This patch makes it configurable through platform data.
Signed-off-by: Shinya Kuribayashi shinya.kuribayashi...@renesas.com
Signed-off-by: Wolfram Sang w.s...@pengutronix.de
But I couldn't find any patches on a public mailing list using the new
clks_per_count field...
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say programmer or something like that.
-- Linus Torvalds
--
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Re: [PATCH 1/5] ARM: shmobile: kzm9g legacy: Set i2c clks_per_count to 2
On Wed, Nov 12, 2014 at 09:53:27AM +0100, Geert Uytterhoeven wrote: Hi Simon, On Wed, Nov 12, 2014 at 2:44 AM, Simon Horman ho...@verge.net.au wrote: On Fri, Nov 07, 2014 at 06:24:21AM +0100, Wolfram Sang wrote: On Thu, Nov 06, 2014 at 12:52:06PM +0100, Geert Uytterhoeven wrote: On sh73a0/kzm9g-legacy, probing of the i2c masters fails with: i2c-sh_mobile i2c-sh_mobile.0: timing values out of range: L/H=0x208/0x1bf sh_mobile: probe of i2c-sh_mobile.0 failed with error -22 Yay, so the warning I added found another bug \o/ According to the datasheet, the transfer rate is derived from the HP clock (which runs at 104 MHz) divided by two. Hence i2c_sh_mobile_platform_data.clks_per_count should be set to two. Now probing succeeds, and i2c works: i2c-sh_mobile i2c-sh_mobile.0: I2C adapter 0 with bus speed 10 Hz (L/H=0x104/0xe0) Signed-off-by: Geert Uytterhoeven geert+rene...@glider.be Reviewed-by: Wolfram Sang wsa+rene...@sang-engineering.com As this appears to be a bug fix I would like to accompany this patch with some text describing when the problem was introduced and what its effects are. In short a rough guide to if it should be applied to -stable. To that end I prepared the following which I would appreciate your feedback on. * ARM: shmobile: kzm9g legacy: Set i2c clks_per_count This problem appears to have been introduced when i2c shmobile support was added to the sh73a9 by b028f94b76319e1b8 (ARM: mach-shmobile: sh73a0 sh73a0 Thanks. i2c_shmobile support.) in v2.6.37. Without this fix i2c may not operate correctly on the sh73a0/kzm9g. Thanks, that's correct. BTW, I guess Kuribayashi-san was aware of the problem: commit ebd5ac165f2aaefb767c53112c2010b0ff3df688 Author: Shinya Kuribayashi shinya.kuribayashi...@renesas.com Date: Wed Oct 24 19:58:10 2012 +0900 i2c: i2c-sh_mobile: support I2C hardware block with a faster operating clock On newer SH-/R-Mobile SoCs, a clock supply to the I2C hardware block, which is used to generate the SCL clock output, is getting faster than before, while on the other hand, the SCL clock control registers, ICCH and ICCL, stay unchanged in 9-bit-wide (8+1). On such silicons, the internal SCL clock counter gets incremented every 2 clocks of the operating clock. This patch makes it configurable through platform data. Signed-off-by: Shinya Kuribayashi shinya.kuribayashi...@renesas.com Signed-off-by: Wolfram Sang w.s...@pengutronix.de But I couldn't find any patches on a public mailing list using the new clks_per_count field... My understanding is that unfortunately Kuribayashi-san is no longer working for Renesas. But I can try to raise this with the BSP team if you like. -- To unsubscribe from this list: send the line unsubscribe linux-i2c in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 1/5] ARM: shmobile: kzm9g legacy: Set i2c clks_per_count to 2
On Wed, Nov 12, 2014 at 09:55:58AM +0100, Geert Uytterhoeven wrote: On Wed, Nov 12, 2014 at 9:53 AM, Geert Uytterhoeven ge...@linux-m68k.org wrote: i2c_shmobile support.) in v2.6.37. Without this fix i2c may not operate correctly on the sh73a0/kzm9g. Thanks, that's correct. git tag --contains b028f94b76319e1b8 says v2.6.38. Not that you're gonna backport it to ltsi-v2.6.37 ;-) Hopefully not! I'll update my description anyway. -- To unsubscribe from this list: send the line unsubscribe linux-i2c in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 1/5] ARM: shmobile: kzm9g legacy: Set i2c clks_per_count to 2
On Fri, Nov 07, 2014 at 06:24:21AM +0100, Wolfram Sang wrote: On Thu, Nov 06, 2014 at 12:52:06PM +0100, Geert Uytterhoeven wrote: On sh73a0/kzm9g-legacy, probing of the i2c masters fails with: i2c-sh_mobile i2c-sh_mobile.0: timing values out of range: L/H=0x208/0x1bf sh_mobile: probe of i2c-sh_mobile.0 failed with error -22 Yay, so the warning I added found another bug \o/ According to the datasheet, the transfer rate is derived from the HP clock (which runs at 104 MHz) divided by two. Hence i2c_sh_mobile_platform_data.clks_per_count should be set to two. Now probing succeeds, and i2c works: i2c-sh_mobile i2c-sh_mobile.0: I2C adapter 0 with bus speed 10 Hz (L/H=0x104/0xe0) Signed-off-by: Geert Uytterhoeven geert+rene...@glider.be Reviewed-by: Wolfram Sang wsa+rene...@sang-engineering.com --- Note that the L/H values still differ from the Transfer Rate Settings example in Table 19.3 of the datasheet, which suggests 0x121/0xe7. Is the formula different or is it rounding errors? Hi Geert, As this appears to be a bug fix I would like to accompany this patch with some text describing when the problem was introduced and what its effects are. In short a rough guide to if it should be applied to -stable. To that end I prepared the following which I would appreciate your feedback on. * ARM: shmobile: kzm9g legacy: Set i2c clks_per_count This problem appears to have been introduced when i2c shmobile support was added to the sh73a9 by b028f94b76319e1b8 (ARM: mach-shmobile: sh73a0 i2c_shmobile support.) in v2.6.37. Without this fix i2c may not operate correctly on the sh73a0/kzm9g. -- To unsubscribe from this list: send the line unsubscribe linux-i2c in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 1/5] ARM: shmobile: kzm9g legacy: Set i2c clks_per_count to 2
On Fri, Nov 07, 2014 at 06:24:21AM +0100, Wolfram Sang wrote: On Thu, Nov 06, 2014 at 12:52:06PM +0100, Geert Uytterhoeven wrote: On sh73a0/kzm9g-legacy, probing of the i2c masters fails with: i2c-sh_mobile i2c-sh_mobile.0: timing values out of range: L/H=0x208/0x1bf sh_mobile: probe of i2c-sh_mobile.0 failed with error -22 Yay, so the warning I added found another bug \o/ According to the datasheet, the transfer rate is derived from the HP clock (which runs at 104 MHz) divided by two. Hence i2c_sh_mobile_platform_data.clks_per_count should be set to two. Now probing succeeds, and i2c works: i2c-sh_mobile i2c-sh_mobile.0: I2C adapter 0 with bus speed 10 Hz (L/H=0x104/0xe0) Signed-off-by: Geert Uytterhoeven geert+rene...@glider.be Reviewed-by: Wolfram Sang wsa+rene...@sang-engineering.com Thanks, I have queued this up. -- To unsubscribe from this list: send the line unsubscribe linux-i2c in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH 1/5] ARM: shmobile: kzm9g legacy: Set i2c clks_per_count to 2
On Thu, Nov 06, 2014 at 12:52:06PM +0100, Geert Uytterhoeven wrote: On sh73a0/kzm9g-legacy, probing of the i2c masters fails with: i2c-sh_mobile i2c-sh_mobile.0: timing values out of range: L/H=0x208/0x1bf sh_mobile: probe of i2c-sh_mobile.0 failed with error -22 Yay, so the warning I added found another bug \o/ According to the datasheet, the transfer rate is derived from the HP clock (which runs at 104 MHz) divided by two. Hence i2c_sh_mobile_platform_data.clks_per_count should be set to two. Now probing succeeds, and i2c works: i2c-sh_mobile i2c-sh_mobile.0: I2C adapter 0 with bus speed 10 Hz (L/H=0x104/0xe0) Signed-off-by: Geert Uytterhoeven geert+rene...@glider.be Reviewed-by: Wolfram Sang wsa+rene...@sang-engineering.com --- Note that the L/H values still differ from the Transfer Rate Settings example in Table 19.3 of the datasheet, which suggests 0x121/0xe7. Is the formula different or is it rounding errors? Thanks, Wolfram signature.asc Description: Digital signature
Re: [PATCH 1/5] ARM: shmobile: kzm9g legacy: Set i2c clks_per_count to 2
Hi Wolfram,
On Fri, Nov 7, 2014 at 6:24 AM, Wolfram Sang w...@the-dreams.de wrote:
Note that the L/H values still differ from the Transfer Rate Settings
example in Table 19.3 of the datasheet, which suggests 0x121/0xe7.
Is the formula different or is it rounding errors?
The formula is different. It doesn't use absolute tLOW, tHIGH, and tF
values, but only the duty cycle of the clock.
It's similar in the R-Car Gen2 docs. Except that on Gen2, there's no
mention of using a duty cycle of 5/3 for High Speed like on AG5.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say programmer or something like that.
-- Linus Torvalds
--
To unsubscribe from this list: send the line unsubscribe linux-i2c in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
