touchscreen: sun4i-ts: Really fix A10 temperature reporting
Subsystems (3)
PATCH 1/1 touchscreen: sun4i-ts: Really fix A10 temperature reporting
The commit titled:
"touchscreen: sun4i-ts: A10 (sun4i) has a different temperature curve" contains a math error, the offset it uses is in degrees, but the actual code applies the offset before multiplying by stepsize :|
Given that this is rather backwards (every math course ever thought applies the multiplication before the offset for linear functions), this commit fixes things by changing the code applying the offset to do the logical thing, adjusting the offset for the other models accordingly.
This has been tested on an A10, A13, A20 and A31 to make sure everything really is correct now.
---
Note if possible this commit should be squashed into the original "touchscreen: sun4i-ts: A10 (sun4i) has a different temperature curve" commit as a fixup.
--- drivers/input/touchscreen/sun4i-ts.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-)
drivers/input/touchscreen/sun4i-ts.c +7 -7
@@ -193,7 +193,7 @@ static int sun4i_get_temp(const struct sun4i_ts_data *ts, long *temp)if (ts->temp_data ==-1 )return -EAGAIN ; - *temp = (ts->temp_data - ts->temp_offset) * ts->temp_step; + *temp = ts->temp_data * ts->temp_step - ts->temp_offset;return 0 ; }
@@ -255,17 +255,17 @@ static int sun4i_ts_probe(struct platform_device *pdev) ts->ignore_fifo_data = true; ts->temp_data =-1 ;if (of_device_is_compatible (np,"allwinner,sun6i-a31-ts" )) { -/* Allwinner SDK has temperature = -271 + (value / 6) (C) */ - ts->temp_offset =1626 ; +/* Allwinner SDK has temperature (C) = (value / 6) - 271 */ + ts->temp_offset =271000 ; ts->temp_step =167 ; }else if (of_device_is_compatible (np,"allwinner,sun4i-a10-ts" )) {/* * The A10 temperature sensor has quite a wide spread, these * parameters are based on the averaging of the calibration * results of 4 completely different boards, with a spread of -* temp_step from 96 - 170 and temp_offset from 1758 - 3310. +* temp_step from 0.096 - 0.170 and temp_offset from 176 - 331. */ - ts->temp_offset =2570 ; + ts->temp_offset =257000 ; ts->temp_step =133 ; }else {/*
@@ -273,13 +273,13 @@ static int sun4i_ts_probe(struct platform_device *pdev)* the temperature. The formula used here is from the AXP209, * which is designed by X-Powers, an affiliate of Allwinner: * -* temperature = -144.7 + (value * 0.1) +* temperature (C) = (value * 0.1) - 144.7 * * Allwinner does not have any documentation whatsoever for * this hardware. Moreover, it is claimed that the sensor * is inaccurate and cannot work properly. */ - ts->temp_offset =1447 ; + ts->temp_offset =144700 ; ts->temp_step =100 ; }
Signature · 1 line
2.3.1
Dmitry Torokhov
maintainerPATCH 1/1 touchscreen: sun4i-ts: Really fix A10 temperature reporting
Quoted 10 lines · Hans de Goede
The commit titled:
"touchscreen: sun4i-ts: A10 (sun4i) has a different temperature curve" contains a math error, the offset it uses is in degrees, but the actual code applies the offset before multiplying by stepsize :|Given that this is rather backwards (every math course ever thought applies the multiplication before the offset for linear functions), this commit fixes things by changing the code applying the offset to do the logical thing, adjusting the offset for the other models accordingly.
Quoted 8 lines
This has been tested on an A10, A13, A20 and A31 to make sure everything really is correct now.
Signed-off-by Hans de Goede <[email protected]>---
Note if possible this commit should be squashed into the original "touchscreen: sun4i-ts: A10 (sun4i) has a different temperature curve" commit as a fixup.
It's a bit too late, I do not like rewinding my 'next' branch unless it is a compile error caught recently. So applied as a separate commit.
Thanks.
Quoted 58 lines
--- drivers/input/touchscreen/sun4i-ts.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-)drivers/input/touchscreen/sun4i-ts.c +7
-7@@ -193,7 +193,7 @@ static int sun4i_get_temp(const struct sun4i_ts_data *ts, long *temp)if (ts->temp_data ==-1 )return -EAGAIN ; - *temp = (ts->temp_data - ts->temp_offset) * ts->temp_step; + *temp = ts->temp_data * ts->temp_step - ts->temp_offset;return 0 ; }@@ -255,17 +255,17 @@ static int sun4i_ts_probe(struct platform_device *pdev) ts->ignore_fifo_data = true; ts->temp_data =-1 ;if (of_device_is_compatible (np,"allwinner,sun6i-a31-ts" )) { -/* Allwinner SDK has temperature = -271 + (value / 6) (C) */ - ts->temp_offset =1626 ; +/* Allwinner SDK has temperature (C) = (value / 6) - 271 */ + ts->temp_offset =271000 ; ts->temp_step =167 ; }else if (of_device_is_compatible (np,"allwinner,sun4i-a10-ts" )) {/* * The A10 temperature sensor has quite a wide spread, these * parameters are based on the averaging of the calibration * results of 4 completely different boards, with a spread of -* temp_step from 96 - 170 and temp_offset from 1758 - 3310. +* temp_step from 0.096 - 0.170 and temp_offset from 176 - 331. */ - ts->temp_offset =2570 ; + ts->temp_offset =257000 ; ts->temp_step =133 ; }else {/* @@ -273,13 +273,13 @@ static int sun4i_ts_probe(struct platform_device *pdev)* the temperature. The formula used here is from the AXP209, * which is designed by X-Powers, an affiliate of Allwinner: * -* temperature = -144.7 + (value * 0.1) +* temperature (C) = (value * 0.1) - 144.7 * * Allwinner does not have any documentation whatsoever for * this hardware. Moreover, it is claimed that the sensor * is inaccurate and cannot work properly. */ - ts->temp_offset =1447 ; + ts->temp_offset =144700 ; ts->temp_step =100 ; }Signature · 1 line
2.3.1
Signature · 1 line
Dmitry
PATCH 1/1 touchscreen: sun4i-ts: Really fix A10 temperature reporting
In reply to Hans de GoedeHi Hans,
is it possible that this patch (and the parent commit "Input: sun4i-ts - allow controlling filter and sensitivity via DT") has quite an adversial effect on other boards than the ones tested?
On my Lemaker Bananapi the temperature is now being reported as somwhere between -15?C to -10?C with the latest Kernel 4.1.0. These negative values are obviously way off. On Kernel 4.0.5 the temperature reading was usually around 40?C. While that might not have been accurate either, it was at least plausible.
Given that there is no Documentation and things seem quite board-specific, I really don't know how this could be improved, so I can merely report my observation.
Kind regards,
Timo
Am Montag, 9. M?rz 2015 10:38:02 UTC+1 schrieb Hans de Goede:
Quoted 75 lines
The commit titled:
"touchscreen: sun4i-ts: A10 (sun4i) has a different temperature curve" contains a math error, the offset it uses is in degrees, but the actual code applies the offset before multiplying by stepsize :|Given that this is rather backwards (every math course ever thought applies the multiplication before the offset for linear functions), this commit fixes things by changing the code applying the offset to do the logical thing, adjusting the offset for the other models accordingly.
This has been tested on an A10, A13, A20 and A31 to make sure everything really is correct now.
Signed-off-by Hans de Goede <[email protected]>---
Note if possible this commit should be squashed into the original "touchscreen: sun4i-ts: A10 (sun4i) has a different temperature curve" commit as a fixup.--- drivers/input/touchscreen/sun4i-ts.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-)drivers/input/touchscreen/sun4i-ts.c +7
-7@@ -193,7 +193,7 @@ static int sun4i_get_temp(const struct sun4i_ts_data *ts, long *temp)if (ts->temp_data ==-1 )return -EAGAIN ; - *temp = (ts->temp_data - ts->temp_offset) * ts->temp_step; + *temp = ts->temp_data * ts->temp_step - ts->temp_offset;return 0 ; }@@ -255,17 +255,17 @@ static int sun4i_ts_probe(struct platform_device *pdev) ts->ignore_fifo_data = true; ts->temp_data =-1 ;if (of_device_is_compatible (np,"allwinner,sun6i-a31-ts" )) { -/* Allwinner SDK has temperature = -271 + (value / 6) (C) */ - ts->temp_offset =1626 ; +/* Allwinner SDK has temperature (C) = (value / 6) - 271 */ + ts->temp_offset =271000 ; ts->temp_step =167 ; }else if (of_device_is_compatible (np,"allwinner,sun4i-a10-ts" )) {/* * The A10 temperature sensor has quite a wide spread, these * parameters are based on the averaging of the calibration * results of 4 completely different boards, with a spread of -* temp_step from 96 - 170 and temp_offset from 1758 - 3310. +* temp_step from 0.096 - 0.170 and temp_offset from 176 - 331. */ - ts->temp_offset =2570 ; + ts->temp_offset =257000 ; ts->temp_step =133 ; }else {/* @@ -273,13 +273,13 @@ static int sun4i_ts_probe(struct platform_device *pdev)* the temperature. The formula used here is from the AXP209, * which is designed by X-Powers, an affiliate of Allwinner: * -* temperature = -144.7 + (value * 0.1) +* temperature (C) = (value * 0.1) - 144.7 * * Allwinner does not have any documentation whatsoever for * this hardware. Moreover, it is claimed that the sensor * is inaccurate and cannot work properly. */ - ts->temp_offset =1447 ; + ts->temp_offset =144700 ; ts->temp_step =100 ; }Signature · 1 line
2.3.1
PATCH 1/1 touchscreen: sun4i-ts: Really fix A10 temperature reporting
Hi,
Quoted 5 lines · m.silentcreek at gmail.com
Hi Hans,
is it possible that this patch (and the parent commit "Input: sun4i-ts - allow controlling filter and sensitivity via DT") has quite an adversial effect on other boards than the ones tested?
On my Lemaker Bananapi the temperature is now being reported as somwhere between -15?C to -10?C with the latest Kernel 4.1.0. These negative values are obviously way off. On Kernel 4.0.5 the temperature reading was usually around 40?C. While that might not have been accurate either, it was at least plausible.
The temperature curve for the A20 SoC was not changed, if it did change then you're using an old dtb file with a new kernel, you must always update your dtb file together with the kernel.
Quoted 82 lines
Given that there is no Documentation and things seem quite board-specific, I really don't know how this could be improved, so I can merely report my observation.
Kind regards,
Timo
Am Montag, 9. M?rz 2015 10:38:02 UTC+1 schrieb Hans de Goede:
Quoted 73 lines
The commit titled:
"touchscreen: sun4i-ts: A10 (sun4i) has a different temperature curve" contains a math error, the offset it uses is in degrees, but the actual code applies the offset before multiplying by stepsize :|Given that this is rather backwards (every math course ever thought applies the multiplication before the offset for linear functions), this commit fixes things by changing the code applying the offset to do the logical thing, adjusting the offset for the other models accordingly.
This has been tested on an A10, A13, A20 and A31 to make sure everything really is correct now.
Signed-off-by Hans de Goede <[email protected]>---
Note if possible this commit should be squashed into the original "touchscreen: sun4i-ts: A10 (sun4i) has a different temperature curve" commit as a fixup.--- drivers/input/touchscreen/sun4i-ts.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-)drivers/input/touchscreen/sun4i-ts.c +7
-7@@ -193,7 +193,7 @@ static int sun4i_get_temp(const struct sun4i_ts_data *ts, long *temp)if (ts->temp_data ==-1 )return -EAGAIN ; - *temp = (ts->temp_data - ts->temp_offset) * ts->temp_step; + *temp = ts->temp_data * ts->temp_step - ts->temp_offset;return 0 ; }@@ -255,17 +255,17 @@ static int sun4i_ts_probe(struct platform_device *pdev) ts->ignore_fifo_data = true; ts->temp_data =-1 ;if (of_device_is_compatible (np,"allwinner,sun6i-a31-ts" )) { -/* Allwinner SDK has temperature = -271 + (value / 6) (C) */ - ts->temp_offset =1626 ; +/* Allwinner SDK has temperature (C) = (value / 6) - 271 */ + ts->temp_offset =271000 ; ts->temp_step =167 ; }else if (of_device_is_compatible (np,"allwinner,sun4i-a10-ts" )) {/* * The A10 temperature sensor has quite a wide spread, these * parameters are based on the averaging of the calibration * results of 4 completely different boards, with a spread of -* temp_step from 96 - 170 and temp_offset from 1758 - 3310. +* temp_step from 0.096 - 0.170 and temp_offset from 176 - 331. */ - ts->temp_offset =2570 ; + ts->temp_offset =257000 ; ts->temp_step =133 ; }else {/* @@ -273,13 +273,13 @@ static int sun4i_ts_probe(struct platform_device *pdev)* the temperature. The formula used here is from the AXP209, * which is designed by X-Powers, an affiliate of Allwinner: * -* temperature = -144.7 + (value * 0.1) +* temperature (C) = (value * 0.1) - 144.7 * * Allwinner does not have any documentation whatsoever for * this hardware. Moreover, it is claimed that the sensor * is inaccurate and cannot work properly. */ - ts->temp_offset =1447 ; + ts->temp_offset =144700 ; ts->temp_step =100 ; }
Quoted 3 lines
Quoted 2 lines
--
2.3.1
Regards,
Hans
Dmitry Torokhov
maintainerPATCH 1/1 touchscreen: sun4i-ts: Really fix A10 temperature reporting
Quoted 5 lines · Hans de Goede
Hi,
Quoted 2 lines · m.silentcreek at gmail.com
Hi Hans,
Quoted 7 lines
Quoted 3 lines
is it possible that this patch (and the parent commit "Input: sun4i-ts - allow controlling filter and sensitivity via DT") has quite an adversial effect on other boards than the ones tested?
On my Lemaker Bananapi the temperature is now being reported as somwhere between -15?C to -10?C with the latest Kernel 4.1.0. These negative values are obviously way off. On Kernel 4.0.5 the temperature reading was usually around 40?C. While that might not have been accurate either, it was at least plausible.
The temperature curve for the A20 SoC was not changed, if it did change then you're using an old dtb file with a new kernel, you must always update your dtb file together with the kernel.
Umm, we should keep compatibility with old DTS...
Quoted 92 lines
Quoted 85 lines
Given that there is no Documentation and things seem quite board-specific, I really don't know how this could be improved, so I can merely report my observation.
Kind regards,
Timo
Am Montag, 9. M?rz 2015 10:38:02 UTC+1 schrieb Hans de Goede:
Quoted 73 lines
The commit titled:
"touchscreen: sun4i-ts: A10 (sun4i) has a different temperature curve" contains a math error, the offset it uses is in degrees, but the actual code applies the offset before multiplying by stepsize :|Given that this is rather backwards (every math course ever thought applies the multiplication before the offset for linear functions), this commit fixes things by changing the code applying the offset to do the logical thing, adjusting the offset for the other models accordingly.
This has been tested on an A10, A13, A20 and A31 to make sure everything really is correct now.
Signed-off-by Hans de Goede <[email protected]>---
Note if possible this commit should be squashed into the original "touchscreen: sun4i-ts: A10 (sun4i) has a different temperature curve" commit as a fixup.--- drivers/input/touchscreen/sun4i-ts.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-)drivers/input/touchscreen/sun4i-ts.c +7
-7@@ -193,7 +193,7 @@ static int sun4i_get_temp(const struct sun4i_ts_data *ts, long *temp)if (ts->temp_data ==-1 )return -EAGAIN ; - *temp = (ts->temp_data - ts->temp_offset) * ts->temp_step; + *temp = ts->temp_data * ts->temp_step - ts->temp_offset;return 0 ; }@@ -255,17 +255,17 @@ static int sun4i_ts_probe(struct platform_device *pdev) ts->ignore_fifo_data = true; ts->temp_data =-1 ;if (of_device_is_compatible (np,"allwinner,sun6i-a31-ts" )) { -/* Allwinner SDK has temperature = -271 + (value / 6) (C) */ - ts->temp_offset =1626 ; +/* Allwinner SDK has temperature (C) = (value / 6) - 271 */ + ts->temp_offset =271000 ; ts->temp_step =167 ; }else if (of_device_is_compatible (np,"allwinner,sun4i-a10-ts" )) {/* * The A10 temperature sensor has quite a wide spread, these * parameters are based on the averaging of the calibration * results of 4 completely different boards, with a spread of -* temp_step from 96 - 170 and temp_offset from 1758 - 3310. +* temp_step from 0.096 - 0.170 and temp_offset from 176 - 331. */ - ts->temp_offset =2570 ; + ts->temp_offset =257000 ; ts->temp_step =133 ; }else {/* @@ -273,13 +273,13 @@ static int sun4i_ts_probe(struct platform_device *pdev)* the temperature. The formula used here is from the AXP209, * which is designed by X-Powers, an affiliate of Allwinner: * -* temperature = -144.7 + (value * 0.1) +* temperature (C) = (value * 0.1) - 144.7 * * Allwinner does not have any documentation whatsoever for * this hardware. Moreover, it is claimed that the sensor * is inaccurate and cannot work properly. */ - ts->temp_offset =1447 ; + ts->temp_offset =144700 ; ts->temp_step =100 ; }Quoted 3 lines
Quoted 2 lines
--
2.3.1Regards,
Hans
Signature · 1 line
Dmitry
PATCH 1/1 touchscreen: sun4i-ts: Really fix A10 temperature reporting
Hi,
Quoted 8 lines · Dmitry Torokhov
Quoted 7 lines · Hans de Goede
Hi,
Quoted 4 lines · m.silentcreek at gmail.com
Hi Hans,
is it possible that this patch (and the parent commit "Input: sun4i-ts - allow controlling filter and sensitivity via DT") has quite an adversial effect on other boards than the ones tested?
Quoted 7 lines
Quoted 5 lines
Quoted 1 line
On my Lemaker Bananapi the temperature is now being reported as somwhere between -15?C to -10?C with the latest Kernel 4.1.0. These negative values are obviously way off. On Kernel 4.0.5 the temperature reading was usually around 40?C. While that might not have been accurate either, it was at least plausible.
The temperature curve for the A20 SoC was not changed, if it did change then you're using an old dtb file with a new kernel, you must always update your dtb file together with the kernel.
Umm, we should keep compatibility with old DTS...
Right, unfortunately that is not always possible, and with sunxi boards the dtb is always shipped together with the kernel, and the dtb as ABI rule really is intended for the case where the dtb ships with the board/firmware.
That does not mean that we can go and break it every other day, but the problem in this case is that we shipped a dts for all boards with a compatible of allwinner,sun4i-a10-ts, and then later on we found out that the temperature curve for the build in temp sensor is different for the A10 compared to the A13/A20, so we adjusted the kernel driver to have 2 temperature curves, 1 for the A10 and one for the later models, and adjusted the compatible in the dts for later models to allwinner,sun5i-a13-ts, note that the actual touchscreen functionality is unchanged and works fine with both compatibles, the only thing which is happening now is that Timo is seeing a different temperature because he is using the new A10 temperature curve on his A20, other then that everything still works 100%, and there really was no other way to deal with this.
Let me also reply to one of Timo's later mails here, as that explains the real problem:
On 23-06-15 23:06, m.silentcreek at gmail.com wrote:> Hi again,
Quoted 2 lines
Am Dienstag, 23. Juni 2015 21:46:25 UTC+2 schrieb Hans de Goede:
<snip>
Quoted 9 lines
Quoted 5 lines
Quoted 1 line
On my Lemaker Bananapi the temperature is now being reported as somwhere between -15?C to -10?C with the latest Kernel 4.1.0. These negative values are obviously way off. On Kernel 4.0.5 the temperature reading was usually around 40?C. While that might not have been accurate either, it was at least plausible.
The temperature curve for the A20 SoC was not changed, if it did change then you're using an old dtb file with a new kernel, you must always update your dtb file together with the kernel.
I just checked the diff for Linux 4.0 and 4.1 and noticed that
sun7i-a20.dtsiin fact has not changed. Is it possible that something that should have been merged got delayed?I looked in Maxime's tree "dt-for-4.2" and found this patch that looks like it could be related: https://git.kernel.org/cgit/linux/kernel/git/mripard/linux.git/commit/?h=sunxi/dt-for-4.2&id=8bf1b9b3d90194a174493febc731f7783f2adf1a
Ah yes, something went wrong during the 4.1 cycle wrt merging ARM patches which have caused almost all ARM patches intended for 4.1 to get delayed to 4.2, including that one, that is the problem.
We did our best to update the driver and the dts in lockstep, and you should have never seen this problem, but the missing of the merge window for all ARM patches during the 4.1 cycle has caused our carefully planned lock-step update to fail, sorry about that.
Maxime I think we should send the mentioned dts patch to stable for 4.1 , do you agree ?
Regards,
Hans
PATCH 1/1 touchscreen: sun4i-ts: Really fix A10 temperature reporting
Hi,
Quoted 2 lines · Hans de Goede
Maxime I think we should send the mentioned dts patch to stable for 4.1 , do you agree ?
Yep. We should definitely do that. You take care of this?
Maxime
Signature · 10 lines
Maxime Ripard, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 819 bytes Desc: Digital signature URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20150624/69db289c/attachment.sig>
PATCH 1/1 touchscreen: sun4i-ts: Really fix A10 temperature reporting
Hi,
Quoted 7 lines · Maxime Ripard
Hi,
Quoted 2 lines · Hans de Goede
Maxime I think we should send the mentioned dts patch to stable for 4.1 , do you agree ?
Yep. We should definitely do that. You take care of this?
Yes I'll try to do so later today.
Regards,
Hans
A message that is not in the archive (sent off-list or not yet received): [email protected]
Hi Hans,
On Wed, Jun 24, 2015 at 9:16 AM, Hans de Goede <[email protected]> wrote:
Ah yes, something went wrong during the 4.1 cycle wrt merging ARM patches
Quoted 9 lines
which have caused almost all ARM patches intended for 4.1 to get delayed to 4.2, including that one, that is the problem.
We did our best to update the driver and the dts in lockstep, and you should
have never seen this problem, but the missing of the merge window for all ARM patches during the 4.1 cycle has caused our carefully planned lock-step update to fail, sorry about that.
No need to apologize. Things happen. Glad to see this cleared up so quickly.
Thanks for the help (and all the other work you do ;)).
Kind regards,
Timo
Signature · 3 lines
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PATCH 1/1 touchscreen: sun4i-ts: Really fix A10 temperature reporting
In reply to Hans de GoedeHi,
Am Dienstag, 23. Juni 2015 21:46:25 UTC+2 schrieb Hans de Goede:
Quoted 5 lines
Hi,
Quoted 2 lines · m.silentcreek at gmail.com
Hi Hans,
Quoted 7 lines
Quoted 3 lines
is it possible that this patch (and the parent commit "Input: sun4i-ts - allow controlling filter and sensitivity via DT") has quite an adversial effect on other boards than the ones tested?
On my Lemaker Bananapi the temperature is now being reported as somwhere between -15?C to -10?C with the latest Kernel 4.1.0. These negative values are obviously way off. On Kernel 4.0.5 the temperature reading was usually around 40?C. While that might not have been accurate either, it was at least plausible.
The temperature curve for the A20 SoC was not changed, if it did change then you're using an old dtb file with a new kernel, you must always update your dtb file together with the kernel.
I always compile the dts that comes with the kernel tree from scratch. So this is up to date. I guess I have to dig in deeper then what caused that change. Any other hint where to look for?
Quoted 85 lines
Quoted 85 lines
Given that there is no Documentation and things seem quite board-specific, I really don't know how this could be improved, so I can merely report my observation.
Kind regards,
Timo
Am Montag, 9. M?rz 2015 10:38:02 UTC+1 schrieb Hans de Goede:
Quoted 73 lines
The commit titled:
"touchscreen: sun4i-ts: A10 (sun4i) has a different temperature curve" contains a math error, the offset it uses is in degrees, but the actual code applies the offset before multiplying by stepsize :|Given that this is rather backwards (every math course ever thought applies the multiplication before the offset for linear functions), this commit fixes things by changing the code applying the offset to do the logical thing, adjusting the offset for the other models accordingly.
This has been tested on an A10, A13, A20 and A31 to make sure everything really is correct now.
Signed-off-by Hans de Goede <[email protected]>---
Note if possible this commit should be squashed into the original "touchscreen: sun4i-ts: A10 (sun4i) has a different temperature curve" commit as a fixup.--- drivers/input/touchscreen/sun4i-ts.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-)drivers/input/touchscreen/sun4i-ts.c +7
-7@@ -193,7 +193,7 @@ static int sun4i_get_temp(const struct sun4i_ts_data *ts, long *temp)if (ts->temp_data ==-1 )return -EAGAIN ; - *temp = (ts->temp_data - ts->temp_offset) * ts->temp_step; + *temp = ts->temp_data * ts->temp_step - ts->temp_offset;return 0 ; }@@ -255,17 +255,17 @@ static int sun4i_ts_probe(struct platform_device *pdev) ts->ignore_fifo_data = true; ts->temp_data =-1 ;if (of_device_is_compatible (np,"allwinner,sun6i-a31-ts" )) { -/* Allwinner SDK has temperature = -271 + (value / 6) (C) */ - ts->temp_offset =1626 ; +/* Allwinner SDK has temperature (C) = (value / 6) - 271 */ + ts->temp_offset =271000 ; ts->temp_step =167 ; }else if (of_device_is_compatible (np,"allwinner,sun4i-a10-ts" )) {/* * The A10 temperature sensor has quite a wide spread, these * parameters are based on the averaging of the calibration * results of 4 completely different boards, with a spread of -* temp_step from 96 - 170 and temp_offset from 1758 - 3310. +* temp_step from 0.096 - 0.170 and temp_offset from 176 - 331. */ - ts->temp_offset =2570 ; + ts->temp_offset =257000 ; ts->temp_step =133 ; }else {/* @@ -273,13 +273,13 @@ static int sun4i_ts_probe(struct platform_device *pdev)* the temperature. The formula used here is from the AXP209, * which is designed by X-Powers, an affiliate of Allwinner: * -* temperature = -144.7 + (value * 0.1) +* temperature (C) = (value * 0.1) - 144.7 * * Allwinner does not have any documentation whatsoever for * this hardware. Moreover, it is claimed that the sensor * is inaccurate and cannot work properly. */ - ts->temp_offset =1447 ; + ts->temp_offset =144700 ; ts->temp_step =100 ; }
Quoted 7 lines
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--
2.3.1Regards,
Hans
Thanks,
Timo
PATCH 1/1 touchscreen: sun4i-ts: Really fix A10 temperature reporting
In reply to Hans de GoedeHi again,
Am Dienstag, 23. Juni 2015 21:46:25 UTC+2 schrieb Hans de Goede:
Quoted 5 lines
Hi,
Quoted 2 lines · m.silentcreek at gmail.com
Hi Hans,
Quoted 7 lines
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is it possible that this patch (and the parent commit "Input: sun4i-ts - allow controlling filter and sensitivity via DT") has quite an adversial effect on other boards than the ones tested?
On my Lemaker Bananapi the temperature is now being reported as somwhere between -15?C to -10?C with the latest Kernel 4.1.0. These negative values are obviously way off. On Kernel 4.0.5 the temperature reading was usually around 40?C. While that might not have been accurate either, it was at least plausible.
The temperature curve for the A20 SoC was not changed, if it did change then you're using an old dtb file with a new kernel, you must always update your dtb file together with the kernel.
I just checked the diff for Linux 4.0 and 4.1 and noticed that sun7i-a20.dtsi in fact has not changed. Is it possible that something that should have been merged got delayed?
I looked in Maxime's tree "dt-for-4.2" and found this patch that looks like it could be related: https://git.kernel.org/cgit/linux/kernel/git/mripard/linux.git/commit/?h=sunxi/dt-for-4.2&id=8bf1b9b3d90194a174493febc731f7783f2adf1a
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Given that there is no Documentation and things seem quite board-specific, I really don't know how this could be improved, so I can merely report my observation.
Kind regards,
Timo
Am Montag, 9. M?rz 2015 10:38:02 UTC+1 schrieb Hans de Goede:
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The commit titled:
"touchscreen: sun4i-ts: A10 (sun4i) has a different temperature curve" contains a math error, the offset it uses is in degrees, but the actual code applies the offset before multiplying by stepsize :|Given that this is rather backwards (every math course ever thought applies the multiplication before the offset for linear functions), this commit fixes things by changing the code applying the offset to do the logical thing, adjusting the offset for the other models accordingly.
This has been tested on an A10, A13, A20 and A31 to make sure everything really is correct now.
Signed-off-by Hans de Goede <[email protected]>---
Note if possible this commit should be squashed into the original "touchscreen: sun4i-ts: A10 (sun4i) has a different temperature curve" commit as a fixup.--- drivers/input/touchscreen/sun4i-ts.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-)drivers/input/touchscreen/sun4i-ts.c +7
-7@@ -193,7 +193,7 @@ static int sun4i_get_temp(const struct sun4i_ts_data *ts, long *temp)if (ts->temp_data ==-1 )return -EAGAIN ; - *temp = (ts->temp_data - ts->temp_offset) * ts->temp_step; + *temp = ts->temp_data * ts->temp_step - ts->temp_offset;return 0 ; }@@ -255,17 +255,17 @@ static int sun4i_ts_probe(struct platform_device *pdev) ts->ignore_fifo_data = true; ts->temp_data =-1 ;if (of_device_is_compatible (np,"allwinner,sun6i-a31-ts" )) { -/* Allwinner SDK has temperature = -271 + (value / 6) (C) */ - ts->temp_offset =1626 ; +/* Allwinner SDK has temperature (C) = (value / 6) - 271 */ + ts->temp_offset =271000 ; ts->temp_step =167 ; }else if (of_device_is_compatible (np,"allwinner,sun4i-a10-ts" )) {/* * The A10 temperature sensor has quite a wide spread, these * parameters are based on the averaging of the calibration * results of 4 completely different boards, with a spread of -* temp_step from 96 - 170 and temp_offset from 1758 - 3310. +* temp_step from 0.096 - 0.170 and temp_offset from 176 - 331. */ - ts->temp_offset =2570 ; + ts->temp_offset =257000 ; ts->temp_step =133 ; }else {/* @@ -273,13 +273,13 @@ static int sun4i_ts_probe(struct platform_device *pdev)* the temperature. The formula used here is from the AXP209, * which is designed by X-Powers, an affiliate of Allwinner: * -* temperature = -144.7 + (value * 0.1) +* temperature (C) = (value * 0.1) - 144.7 * * Allwinner does not have any documentation whatsoever for * this hardware. Moreover, it is claimed that the sensor * is inaccurate and cannot work properly. */ - ts->temp_offset =1447 ; + ts->temp_offset =144700 ; ts->temp_step =100 ; }
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2.3.1Regards,
Hans
Regards,
Timo