| Message ID | 20220513151845.2802795-2-mkorpershoek@baylibre.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Input: mt6779-keypad - fix hw code logic and row/col selection | expand |
On Fri, May 13, 2022 at 05:18:44PM +0200, Mattijs Korpershoek wrote: > In mt6779_keypad_irq_handler(), we > 1. Read a hardware code from KPD_MEM1 -> KPD_MEM5 > 2. Use that hardware code to compute columns/rows for the standard > keyboard matrix. > > According to the (non-public) datasheet, the > map between the hardware code and the cols/rows is: > > |(0) |(1) |(2) > ----*-----*-----*----- > | | | > |(9) |(10) |(11) > ----*-----*-----*----- > | | | > |(18) |(19) |(20) > ----*-----*-----*----- > | | | > > This brings us to another formula: > -> row = code / 9; > -> col = code % 3; What if there are more than 3 columns? > > Implement this mapping in bitnr_to_col_row() to fetch the > correct input event from keypad->input_dev->keycode and report that > back to userspace. > > Fixes: f28af984e771 ("Input: mt6779-keypad - add MediaTek keypad driver") > Co-developed-by: Fabien Parent <fparent@baylibre.com> > Signed-off-by: Fabien Parent <fparent@baylibre.com> > Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com> > --- > drivers/input/keyboard/mt6779-keypad.c | 16 ++++++++++++++-- > 1 file changed, 14 insertions(+), 2 deletions(-) > > diff --git a/drivers/input/keyboard/mt6779-keypad.c b/drivers/input/keyboard/mt6779-keypad.c > index 2e7c9187c10f..23360de20da5 100644 > --- a/drivers/input/keyboard/mt6779-keypad.c > +++ b/drivers/input/keyboard/mt6779-keypad.c > @@ -36,6 +36,19 @@ static const struct regmap_config mt6779_keypad_regmap_cfg = { > .max_register = 36, > }; > > +/* > + * | hardware key code | col0 | col1 | col2| > + * | ----------------- | -----| ---- | --- | > + * | row0 | 0 | 1 | 2 | > + * | row1 | 9 | 10 | 11 | > + * | row2 | 18 | 19 | 20 | > + */ > +static void bitnr_to_col_row(int bit_nr, int *col, int *row) > +{ > + *row = bit_nr / 9; > + *col = bit_nr % 3; > +} > + > static irqreturn_t mt6779_keypad_irq_handler(int irq, void *dev_id) > { > struct mt6779_keypad *keypad = dev_id; > @@ -61,8 +74,7 @@ static irqreturn_t mt6779_keypad_irq_handler(int irq, void *dev_id) > if (bit_nr % 32 >= 16) > continue; > > - row = bit_nr / 32; > - col = bit_nr % 32; > + bitnr_to_col_row(bit_nr, &col, &row); > scancode = MATRIX_SCAN_CODE(row, col, row_shift); > /* 1: not pressed, 0: pressed */ > pressed = !test_bit(bit_nr, new_state); > -- > 2.32.0 >
Hi Dmitry, Thank you for your review, On dim., mai 15, 2022 at 22:23, Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote: > On Fri, May 13, 2022 at 05:18:44PM +0200, Mattijs Korpershoek wrote: >> In mt6779_keypad_irq_handler(), we >> 1. Read a hardware code from KPD_MEM1 -> KPD_MEM5 >> 2. Use that hardware code to compute columns/rows for the standard >> keyboard matrix. >> >> According to the (non-public) datasheet, the >> map between the hardware code and the cols/rows is: >> >> |(0) |(1) |(2) >> ----*-----*-----*----- >> | | | >> |(9) |(10) |(11) >> ----*-----*-----*----- >> | | | >> |(18) |(19) |(20) >> ----*-----*-----*----- >> | | | >> >> This brings us to another formula: >> -> row = code / 9; >> -> col = code % 3; > > What if there are more than 3 columns? That's not supported, in hardware, according to the datasheet. The datasheet I have states that "The interface of MT6763 only supports 3*3 single or 2*2 double, but internal ASIC still detects keys in the manner of 8*8 single, and 3*3 double. The registers and key codes still follows the legacy naming". Should I add another patch in this series to add that limitation in the probe? There are no checks done in the probe() right now. > >> >> Implement this mapping in bitnr_to_col_row() to fetch the >> correct input event from keypad->input_dev->keycode and report that >> back to userspace. >> >> Fixes: f28af984e771 ("Input: mt6779-keypad - add MediaTek keypad driver") >> Co-developed-by: Fabien Parent <fparent@baylibre.com> >> Signed-off-by: Fabien Parent <fparent@baylibre.com> >> Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com> >> --- >> drivers/input/keyboard/mt6779-keypad.c | 16 ++++++++++++++-- >> 1 file changed, 14 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/input/keyboard/mt6779-keypad.c b/drivers/input/keyboard/mt6779-keypad.c >> index 2e7c9187c10f..23360de20da5 100644 >> --- a/drivers/input/keyboard/mt6779-keypad.c >> +++ b/drivers/input/keyboard/mt6779-keypad.c >> @@ -36,6 +36,19 @@ static const struct regmap_config mt6779_keypad_regmap_cfg = { >> .max_register = 36, >> }; >> >> +/* >> + * | hardware key code | col0 | col1 | col2| >> + * | ----------------- | -----| ---- | --- | >> + * | row0 | 0 | 1 | 2 | >> + * | row1 | 9 | 10 | 11 | >> + * | row2 | 18 | 19 | 20 | >> + */ >> +static void bitnr_to_col_row(int bit_nr, int *col, int *row) >> +{ >> + *row = bit_nr / 9; >> + *col = bit_nr % 3; >> +} >> + >> static irqreturn_t mt6779_keypad_irq_handler(int irq, void *dev_id) >> { >> struct mt6779_keypad *keypad = dev_id; >> @@ -61,8 +74,7 @@ static irqreturn_t mt6779_keypad_irq_handler(int irq, void *dev_id) >> if (bit_nr % 32 >= 16) >> continue; >> >> - row = bit_nr / 32; >> - col = bit_nr % 32; >> + bitnr_to_col_row(bit_nr, &col, &row); >> scancode = MATRIX_SCAN_CODE(row, col, row_shift); >> /* 1: not pressed, 0: pressed */ >> pressed = !test_bit(bit_nr, new_state); >> -- >> 2.32.0 >> > > -- > Dmitry
Il 16/05/22 09:30, Mattijs Korpershoek ha scritto: > Hi Dmitry, > > Thank you for your review, > > On dim., mai 15, 2022 at 22:23, Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote: > >> On Fri, May 13, 2022 at 05:18:44PM +0200, Mattijs Korpershoek wrote: >>> In mt6779_keypad_irq_handler(), we >>> 1. Read a hardware code from KPD_MEM1 -> KPD_MEM5 >>> 2. Use that hardware code to compute columns/rows for the standard >>> keyboard matrix. >>> >>> According to the (non-public) datasheet, the >>> map between the hardware code and the cols/rows is: >>> >>> |(0) |(1) |(2) >>> ----*-----*-----*----- >>> | | | >>> |(9) |(10) |(11) >>> ----*-----*-----*----- >>> | | | >>> |(18) |(19) |(20) >>> ----*-----*-----*----- >>> | | | >>> >>> This brings us to another formula: >>> -> row = code / 9; >>> -> col = code % 3; >> >> What if there are more than 3 columns? > That's not supported, in hardware, according to the datasheet. > > The datasheet I have states that "The interface of MT6763 only supports > 3*3 single or 2*2 double, but internal ASIC still detects keys in the > manner of 8*8 single, and 3*3 double. The registers and key codes still > follows the legacy naming". > > Should I add another patch in this series to add that limitation in the > probe? There are no checks done in the probe() right now. > I've just checked a downstream kernel for MT6795 and that one looks like being fully compatible with this driver as well... and as far as downstream is concerned, apparently, mt6735, 6739, 6755, 6757, 6758, 6763, 6771, 6775 all have the same register layout and the downstream driver for these is always the very same one... ...so, I don't think that there's currently any SoC that supports more than three columns. Besides, a fast check shows that MT8195 also has the same. At this point, I'd say that assuming that there are 3 columns, nor less, not more, is just fine. To stay on the safe side, though, perhaps add a comment explaining that this driver works on that assumption? ..but that's clear, anyway, if you actually read the code. From my perspective, this commit is good to go. Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
On Mon, May 16, 2022 at 13:06, AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> wrote: > Il 16/05/22 09:30, Mattijs Korpershoek ha scritto: >> Hi Dmitry, >> >> Thank you for your review, >> >> On dim., mai 15, 2022 at 22:23, Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote: >> >>> On Fri, May 13, 2022 at 05:18:44PM +0200, Mattijs Korpershoek wrote: >>>> In mt6779_keypad_irq_handler(), we >>>> 1. Read a hardware code from KPD_MEM1 -> KPD_MEM5 >>>> 2. Use that hardware code to compute columns/rows for the standard >>>> keyboard matrix. >>>> >>>> According to the (non-public) datasheet, the >>>> map between the hardware code and the cols/rows is: >>>> >>>> |(0) |(1) |(2) >>>> ----*-----*-----*----- >>>> | | | >>>> |(9) |(10) |(11) >>>> ----*-----*-----*----- >>>> | | | >>>> |(18) |(19) |(20) >>>> ----*-----*-----*----- >>>> | | | >>>> >>>> This brings us to another formula: >>>> -> row = code / 9; >>>> -> col = code % 3; >>> >>> What if there are more than 3 columns? >> That's not supported, in hardware, according to the datasheet. >> >> The datasheet I have states that "The interface of MT6763 only supports >> 3*3 single or 2*2 double, but internal ASIC still detects keys in the >> manner of 8*8 single, and 3*3 double. The registers and key codes still >> follows the legacy naming". >> >> Should I add another patch in this series to add that limitation in the >> probe? There are no checks done in the probe() right now. >> > > I've just checked a downstream kernel for MT6795 and that one looks like > being fully compatible with this driver as well... and as far as downstream > is concerned, apparently, mt6735, 6739, 6755, 6757, 6758, 6763, 6771, 6775 > all have the same register layout and the downstream driver for these is > always the very same one... Thank you for taking the time to check in your downstream kernels, I really appreciate it. > > ...so, I don't think that there's currently any SoC that supports more than > three columns. Besides, a fast check shows that MT8195 also has the same. > At this point, I'd say that assuming that there are 3 columns, nor less, not > more, is just fine. > > To stay on the safe side, though, perhaps add a comment explaining that > this driver works on that assumption? ..but that's clear, anyway, if you > actually read the code. > > From my perspective, this commit is good to go. I will keep as is for v2 series and apply your review tag. thanks again ! > > Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
On Mon, May 16, 2022 at 01:06:43PM +0200, AngeloGioacchino Del Regno wrote: > Il 16/05/22 09:30, Mattijs Korpershoek ha scritto: > > Hi Dmitry, > > > > Thank you for your review, > > > > On dim., mai 15, 2022 at 22:23, Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote: > > > > > On Fri, May 13, 2022 at 05:18:44PM +0200, Mattijs Korpershoek wrote: > > > > In mt6779_keypad_irq_handler(), we > > > > 1. Read a hardware code from KPD_MEM1 -> KPD_MEM5 > > > > 2. Use that hardware code to compute columns/rows for the standard > > > > keyboard matrix. > > > > > > > > According to the (non-public) datasheet, the > > > > map between the hardware code and the cols/rows is: > > > > > > > > |(0) |(1) |(2) > > > > ----*-----*-----*----- > > > > | | | > > > > |(9) |(10) |(11) > > > > ----*-----*-----*----- > > > > | | | > > > > |(18) |(19) |(20) > > > > ----*-----*-----*----- > > > > | | | > > > > > > > > This brings us to another formula: > > > > -> row = code / 9; > > > > -> col = code % 3; > > > > > > What if there are more than 3 columns? > > That's not supported, in hardware, according to the datasheet. > > > > The datasheet I have states that "The interface of MT6763 only supports > > 3*3 single or 2*2 double, but internal ASIC still detects keys in the > > manner of 8*8 single, and 3*3 double. The registers and key codes still > > follows the legacy naming". > > > > Should I add another patch in this series to add that limitation in the > > probe? There are no checks done in the probe() right now. > > > > I've just checked a downstream kernel for MT6795 and that one looks like > being fully compatible with this driver as well... and as far as downstream > is concerned, apparently, mt6735, 6739, 6755, 6757, 6758, 6763, 6771, 6775 > all have the same register layout and the downstream driver for these is > always the very same one... > > ...so, I don't think that there's currently any SoC that supports more than > three columns. Besides, a fast check shows that MT8195 also has the same. > At this point, I'd say that assuming that there are 3 columns, nor less, not > more, is just fine. OK, now that I looked at the datasheet I remember how it came about. The programming (register) interface does not really care about how actual matrix is organized, and instead has a set of bits representing keys, from KEY0 to KEY77, arranged in 5 chunks of 15 bits split into 5 32-bit registers. So we simply decided to use register number as row and offset in the register as column when encoding our "matrix". This does not match the actual keypad matrix organization, so if we want to change this, that's fine, but then we also need to recognize that we are skipping bits 16-31, 48-63, and so on, so to get to the right key number we need to do something like: key = bit_nr / 32 * 16 + bit_nr % 32; row = key / 9; col = key % 9; I looked at the datasheets I have and they talk about 8x8 single keypad matrix, and 3x3 double keypad (with actual matrices either 3x3 or 2x2) but I do not actually see this map layout that Mattijs drew documented anywhere though... I also wonder if there are already existing DTSes in the wild that will be rendered invalid by these changes. I wonder if it would not be be better to document the existing meaning of row and column in the driver? Thanks.
On dim., mai 22, 2022 at 22:42, Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote: > On Mon, May 16, 2022 at 01:06:43PM +0200, AngeloGioacchino Del Regno wrote: >> Il 16/05/22 09:30, Mattijs Korpershoek ha scritto: >> > Hi Dmitry, >> > >> > Thank you for your review, >> > >> > On dim., mai 15, 2022 at 22:23, Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote: >> > >> > > On Fri, May 13, 2022 at 05:18:44PM +0200, Mattijs Korpershoek wrote: >> > > > In mt6779_keypad_irq_handler(), we >> > > > 1. Read a hardware code from KPD_MEM1 -> KPD_MEM5 >> > > > 2. Use that hardware code to compute columns/rows for the standard >> > > > keyboard matrix. >> > > > >> > > > According to the (non-public) datasheet, the >> > > > map between the hardware code and the cols/rows is: >> > > > >> > > > |(0) |(1) |(2) >> > > > ----*-----*-----*----- >> > > > | | | >> > > > |(9) |(10) |(11) >> > > > ----*-----*-----*----- >> > > > | | | >> > > > |(18) |(19) |(20) >> > > > ----*-----*-----*----- >> > > > | | | >> > > > >> > > > This brings us to another formula: >> > > > -> row = code / 9; >> > > > -> col = code % 3; >> > > >> > > What if there are more than 3 columns? >> > That's not supported, in hardware, according to the datasheet. >> > >> > The datasheet I have states that "The interface of MT6763 only supports >> > 3*3 single or 2*2 double, but internal ASIC still detects keys in the >> > manner of 8*8 single, and 3*3 double. The registers and key codes still >> > follows the legacy naming". >> > >> > Should I add another patch in this series to add that limitation in the >> > probe? There are no checks done in the probe() right now. >> > >> >> I've just checked a downstream kernel for MT6795 and that one looks like >> being fully compatible with this driver as well... and as far as downstream >> is concerned, apparently, mt6735, 6739, 6755, 6757, 6758, 6763, 6771, 6775 >> all have the same register layout and the downstream driver for these is >> always the very same one... >> >> ...so, I don't think that there's currently any SoC that supports more than >> three columns. Besides, a fast check shows that MT8195 also has the same. >> At this point, I'd say that assuming that there are 3 columns, nor less, not >> more, is just fine. > > OK, now that I looked at the datasheet I remember how it came about. The > programming (register) interface does not really care about how actual > matrix is organized, and instead has a set of bits representing keys, > from KEY0 to KEY77, arranged in 5 chunks of 15 bits split into 5 32-bit > registers. So we simply decided to use register number as row and > offset in the register as column when encoding our "matrix". That's correct and that's a good way to phrase it. I will add that in the commit message. > > This does not match the actual keypad matrix organization, so if we want > to change this, that's fine, but then we also need to recognize that we > are skipping bits 16-31, 48-63, and so on, so to get to the right key > number we need to do something like: > > key = bit_nr / 32 * 16 + bit_nr % 32; > row = key / 9; > col = key % 9; I would prefer to have the driver's matrix_keypad (build in probe()) to match the actual hardware. To me this seems easier to understand for people familiar with the hardware. I've also tested the above snippet and it matches my expectations. > > I looked at the datasheets I have and they talk about 8x8 single keypad > matrix, and 3x3 double keypad (with actual matrices either 3x3 or 2x2) Indeed. I plan to send out double keypad support for this driver since that's actually needed for mt8183-pumpkin as well. It's already in our mtk-v5.10[1] integration tree but I have not submitted it yet. I planned to send this a separate series to avoid burdening / have smaller chunks to review. If that was a mistake, please let me know. > but I do not actually see this map layout that Mattijs drew documented The map layout that I draw is not directly copied from the datasheet. It's a "translation" of the following table: | hardware key code | col0 | col1 | col2| | ----------------- | -----| ---- | --- | | row0 | 0 | 1 | 2 | | row1 | 9 | 10 | 11 | | row2 | 18 | 19 | 20 | It seems that caused more confusion than actual useful information, sorry about that. > anywhere though... I also wonder if there are already existing DTSes in > the wild that will be rendered invalid by these changes. I wonder if it > would not be be better to document the existing meaning of row and > column in the driver? The concern for "DTSes in the wild" that will break is a valid point. I'm not aware of any of those. Most vendor trees i've seen don't use this driver at all. I hope that will change at some point. In the end. I'd prefer to have the driver's keypad matrix match the actual hardware. Right now we can have a 5x32 matrix which seems absurd. Having at most an 8x8 is more reasonable. I'd like to send v3 with just fixing the row/column suggestion in mt6779_keypad_irq_handler() that Dmitry suggested. Would that work Dmitry? [1] https://gitlab.com/mediatek/aiot/bsp/linux/-/tree/mtk-v5.10 > Thanks. > > -- > Dmitry
On Tue, May 24, 2022 at 09:21:28PM +0200, Mattijs Korpershoek wrote: > On dim., mai 22, 2022 at 22:42, Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote: > > > On Mon, May 16, 2022 at 01:06:43PM +0200, AngeloGioacchino Del Regno wrote: > >> Il 16/05/22 09:30, Mattijs Korpershoek ha scritto: > >> > Hi Dmitry, > >> > > >> > Thank you for your review, > >> > > >> > On dim., mai 15, 2022 at 22:23, Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote: > >> > > >> > > On Fri, May 13, 2022 at 05:18:44PM +0200, Mattijs Korpershoek wrote: > >> > > > In mt6779_keypad_irq_handler(), we > >> > > > 1. Read a hardware code from KPD_MEM1 -> KPD_MEM5 > >> > > > 2. Use that hardware code to compute columns/rows for the standard > >> > > > keyboard matrix. > >> > > > > >> > > > According to the (non-public) datasheet, the > >> > > > map between the hardware code and the cols/rows is: > >> > > > > >> > > > |(0) |(1) |(2) > >> > > > ----*-----*-----*----- > >> > > > | | | > >> > > > |(9) |(10) |(11) > >> > > > ----*-----*-----*----- > >> > > > | | | > >> > > > |(18) |(19) |(20) > >> > > > ----*-----*-----*----- > >> > > > | | | > >> > > > > >> > > > This brings us to another formula: > >> > > > -> row = code / 9; > >> > > > -> col = code % 3; > >> > > > >> > > What if there are more than 3 columns? > >> > That's not supported, in hardware, according to the datasheet. > >> > > >> > The datasheet I have states that "The interface of MT6763 only supports > >> > 3*3 single or 2*2 double, but internal ASIC still detects keys in the > >> > manner of 8*8 single, and 3*3 double. The registers and key codes still > >> > follows the legacy naming". > >> > > >> > Should I add another patch in this series to add that limitation in the > >> > probe? There are no checks done in the probe() right now. > >> > > >> > >> I've just checked a downstream kernel for MT6795 and that one looks like > >> being fully compatible with this driver as well... and as far as downstream > >> is concerned, apparently, mt6735, 6739, 6755, 6757, 6758, 6763, 6771, 6775 > >> all have the same register layout and the downstream driver for these is > >> always the very same one... > >> > >> ...so, I don't think that there's currently any SoC that supports more than > >> three columns. Besides, a fast check shows that MT8195 also has the same. > >> At this point, I'd say that assuming that there are 3 columns, nor less, not > >> more, is just fine. > > > > OK, now that I looked at the datasheet I remember how it came about. The > > programming (register) interface does not really care about how actual > > matrix is organized, and instead has a set of bits representing keys, > > from KEY0 to KEY77, arranged in 5 chunks of 15 bits split into 5 32-bit > > registers. So we simply decided to use register number as row and > > offset in the register as column when encoding our "matrix". > > That's correct and that's a good way to phrase it. > I will add that in the commit message. > > > > > This does not match the actual keypad matrix organization, so if we want > > to change this, that's fine, but then we also need to recognize that we > > are skipping bits 16-31, 48-63, and so on, so to get to the right key > > number we need to do something like: > > > > key = bit_nr / 32 * 16 + bit_nr % 32; > > row = key / 9; > > col = key % 9; > > I would prefer to have the driver's matrix_keypad (build in probe()) to > match the actual hardware. To me this seems easier to understand for > people familiar with the hardware. > > I've also tested the above snippet and it matches my expectations. > > > > > I looked at the datasheets I have and they talk about 8x8 single keypad > > matrix, and 3x3 double keypad (with actual matrices either 3x3 or 2x2) > > Indeed. I plan to send out double keypad support for this driver since > that's actually needed for mt8183-pumpkin as well. > It's already in our mtk-v5.10[1] integration tree but I have not submitted > it yet. > I planned to send this a separate series to avoid burdening / have > smaller chunks to review. If that was a mistake, please let me know. > > > but I do not actually see this map layout that Mattijs drew documented > > The map layout that I draw is not directly copied from the datasheet. > It's a "translation" of the following table: > > | hardware key code | col0 | col1 | col2| > | ----------------- | -----| ---- | --- | > | row0 | 0 | 1 | 2 | > | row1 | 9 | 10 | 11 | > | row2 | 18 | 19 | 20 | > > It seems that caused more confusion than actual useful information, > sorry about that. > > > anywhere though... I also wonder if there are already existing DTSes in > > the wild that will be rendered invalid by these changes. I wonder if it > > would not be be better to document the existing meaning of row and > > column in the driver? > > The concern for "DTSes in the wild" that will break is a valid point. > I'm not aware of any of those. Most vendor trees i've seen don't use > this driver at all. I hope that will change at some point. > > In the end. I'd prefer to have the driver's keypad matrix match > the actual hardware. Right now we can have a 5x32 matrix which seems > absurd. Having at most an 8x8 is more reasonable. > > I'd like to send v3 with just fixing the row/column suggestion in > mt6779_keypad_irq_handler() that Dmitry suggested. > > Would that work Dmitry? OK, let's do that. Although I'd be curious to see the double keypad patches as according to the datasheets I saw the translation is different for those. Thanks.
On sam., mai 28, 2022 at 22:23, Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote: > On Tue, May 24, 2022 at 09:21:28PM +0200, Mattijs Korpershoek wrote: >> On dim., mai 22, 2022 at 22:42, Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote: >> >> > On Mon, May 16, 2022 at 01:06:43PM +0200, AngeloGioacchino Del Regno wrote: >> >> Il 16/05/22 09:30, Mattijs Korpershoek ha scritto: >> >> > Hi Dmitry, >> >> > >> >> > Thank you for your review, >> >> > >> >> > On dim., mai 15, 2022 at 22:23, Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote: >> >> > >> >> > > On Fri, May 13, 2022 at 05:18:44PM +0200, Mattijs Korpershoek wrote: >> >> > > > In mt6779_keypad_irq_handler(), we >> >> > > > 1. Read a hardware code from KPD_MEM1 -> KPD_MEM5 >> >> > > > 2. Use that hardware code to compute columns/rows for the standard >> >> > > > keyboard matrix. >> >> > > > >> >> > > > According to the (non-public) datasheet, the >> >> > > > map between the hardware code and the cols/rows is: >> >> > > > >> >> > > > |(0) |(1) |(2) >> >> > > > ----*-----*-----*----- >> >> > > > | | | >> >> > > > |(9) |(10) |(11) >> >> > > > ----*-----*-----*----- >> >> > > > | | | >> >> > > > |(18) |(19) |(20) >> >> > > > ----*-----*-----*----- >> >> > > > | | | >> >> > > > >> >> > > > This brings us to another formula: >> >> > > > -> row = code / 9; >> >> > > > -> col = code % 3; >> >> > > >> >> > > What if there are more than 3 columns? >> >> > That's not supported, in hardware, according to the datasheet. >> >> > >> >> > The datasheet I have states that "The interface of MT6763 only supports >> >> > 3*3 single or 2*2 double, but internal ASIC still detects keys in the >> >> > manner of 8*8 single, and 3*3 double. The registers and key codes still >> >> > follows the legacy naming". >> >> > >> >> > Should I add another patch in this series to add that limitation in the >> >> > probe? There are no checks done in the probe() right now. >> >> > >> >> >> >> I've just checked a downstream kernel for MT6795 and that one looks like >> >> being fully compatible with this driver as well... and as far as downstream >> >> is concerned, apparently, mt6735, 6739, 6755, 6757, 6758, 6763, 6771, 6775 >> >> all have the same register layout and the downstream driver for these is >> >> always the very same one... >> >> >> >> ...so, I don't think that there's currently any SoC that supports more than >> >> three columns. Besides, a fast check shows that MT8195 also has the same. >> >> At this point, I'd say that assuming that there are 3 columns, nor less, not >> >> more, is just fine. >> > >> > OK, now that I looked at the datasheet I remember how it came about. The >> > programming (register) interface does not really care about how actual >> > matrix is organized, and instead has a set of bits representing keys, >> > from KEY0 to KEY77, arranged in 5 chunks of 15 bits split into 5 32-bit >> > registers. So we simply decided to use register number as row and >> > offset in the register as column when encoding our "matrix". >> >> That's correct and that's a good way to phrase it. >> I will add that in the commit message. >> >> > >> > This does not match the actual keypad matrix organization, so if we want >> > to change this, that's fine, but then we also need to recognize that we >> > are skipping bits 16-31, 48-63, and so on, so to get to the right key >> > number we need to do something like: >> > >> > key = bit_nr / 32 * 16 + bit_nr % 32; >> > row = key / 9; >> > col = key % 9; >> >> I would prefer to have the driver's matrix_keypad (build in probe()) to >> match the actual hardware. To me this seems easier to understand for >> people familiar with the hardware. >> >> I've also tested the above snippet and it matches my expectations. >> >> > >> > I looked at the datasheets I have and they talk about 8x8 single keypad >> > matrix, and 3x3 double keypad (with actual matrices either 3x3 or 2x2) >> >> Indeed. I plan to send out double keypad support for this driver since >> that's actually needed for mt8183-pumpkin as well. >> It's already in our mtk-v5.10[1] integration tree but I have not submitted >> it yet. >> I planned to send this a separate series to avoid burdening / have >> smaller chunks to review. If that was a mistake, please let me know. >> >> > but I do not actually see this map layout that Mattijs drew documented >> >> The map layout that I draw is not directly copied from the datasheet. >> It's a "translation" of the following table: >> >> | hardware key code | col0 | col1 | col2| >> | ----------------- | -----| ---- | --- | >> | row0 | 0 | 1 | 2 | >> | row1 | 9 | 10 | 11 | >> | row2 | 18 | 19 | 20 | >> >> It seems that caused more confusion than actual useful information, >> sorry about that. >> >> > anywhere though... I also wonder if there are already existing DTSes in >> > the wild that will be rendered invalid by these changes. I wonder if it >> > would not be be better to document the existing meaning of row and >> > column in the driver? >> >> The concern for "DTSes in the wild" that will break is a valid point. >> I'm not aware of any of those. Most vendor trees i've seen don't use >> this driver at all. I hope that will change at some point. >> >> In the end. I'd prefer to have the driver's keypad matrix match >> the actual hardware. Right now we can have a 5x32 matrix which seems >> absurd. Having at most an 8x8 is more reasonable. >> >> I'd like to send v3 with just fixing the row/column suggestion in >> mt6779_keypad_irq_handler() that Dmitry suggested. >> >> Would that work Dmitry? > > OK, let's do that. Although I'd be curious to see the double keypad > patches as according to the datasheets I saw the translation is > different for those. Sorry for the delay. I had some long needed away time from my computer. Yes, it's a different translation for double keypad. I will send a v3 to fix single keys and make sure to send the double keypad support afterwards. > > Thanks. > > -- > Dmitry
diff --git a/drivers/input/keyboard/mt6779-keypad.c b/drivers/input/keyboard/mt6779-keypad.c index 2e7c9187c10f..23360de20da5 100644 --- a/drivers/input/keyboard/mt6779-keypad.c +++ b/drivers/input/keyboard/mt6779-keypad.c @@ -36,6 +36,19 @@ static const struct regmap_config mt6779_keypad_regmap_cfg = { .max_register = 36, }; +/* + * | hardware key code | col0 | col1 | col2| + * | ----------------- | -----| ---- | --- | + * | row0 | 0 | 1 | 2 | + * | row1 | 9 | 10 | 11 | + * | row2 | 18 | 19 | 20 | + */ +static void bitnr_to_col_row(int bit_nr, int *col, int *row) +{ + *row = bit_nr / 9; + *col = bit_nr % 3; +} + static irqreturn_t mt6779_keypad_irq_handler(int irq, void *dev_id) { struct mt6779_keypad *keypad = dev_id; @@ -61,8 +74,7 @@ static irqreturn_t mt6779_keypad_irq_handler(int irq, void *dev_id) if (bit_nr % 32 >= 16) continue; - row = bit_nr / 32; - col = bit_nr % 32; + bitnr_to_col_row(bit_nr, &col, &row); scancode = MATRIX_SCAN_CODE(row, col, row_shift); /* 1: not pressed, 0: pressed */ pressed = !test_bit(bit_nr, new_state);
In mt6779_keypad_irq_handler(), we 1. Read a hardware code from KPD_MEM1 -> KPD_MEM5 2. Use that hardware code to compute columns/rows for the standard keyboard matrix. According to the (non-public) datasheet, the map between the hardware code and the cols/rows is: |(0) |(1) |(2) ----*-----*-----*----- | | | |(9) |(10) |(11) ----*-----*-----*----- | | | |(18) |(19) |(20) ----*-----*-----*----- | | | This brings us to another formula: -> row = code / 9; -> col = code % 3; Implement this mapping in bitnr_to_col_row() to fetch the correct input event from keypad->input_dev->keycode and report that back to userspace. Fixes: f28af984e771 ("Input: mt6779-keypad - add MediaTek keypad driver") Co-developed-by: Fabien Parent <fparent@baylibre.com> Signed-off-by: Fabien Parent <fparent@baylibre.com> Signed-off-by: Mattijs Korpershoek <mkorpershoek@baylibre.com> --- drivers/input/keyboard/mt6779-keypad.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-)