# \[PATCH v6 0/4\] add z1 and z2 channels support for resistive-adc-touch driver - Subsystems: GENERIC RESISTIVE TOUCHSCREEN ADC DRIVER, INPUT (KEYBOARD, MOUSE, JOYSTICK, TOUCHSCREEN) DRIVERS, OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS, THE REST - Maintainers: Eugen Hristev, Dmitry Torokhov, Rob Herring, Krzysztof Kozlowski, Conor Dooley, Linus Torvalds - Series: 4 patches touching 4 files, +218/-47 - Status: LANDED - Landed in mainline. - Revision v6 (5 revisions archived). - List: linux-input - 8 messages, 3 authors - Page: https://ratatoskr.run/linux-input/2021/05/1390801/t ## \[PATCH v6 0/4\] add z1 and z2 channels support for resistive-adc-touch driver - From: Oleksij Rempel \ - Date: 2021-05-25 05:46:56 - Message: https://ratatoskr.run/linux-input/2021/05/1390801.md ```text changes v6: - drop other DT changes - add more Reviewed-by tags - remove redundant GRTS_CH_NONE check changes v5: - fix validate for other DT examples. - add Reviewed-by: Rob Herring [ref] to some of the patches changes v4: - resistive-adc-touch: remove unused variable changes v3: - yaml: fix validation for channel names - yaml: add nodename validation changes v2: - add yaml conversion patch to this series - reword commit message for the last patch - fix possible overflow on the buffer dispatcher Oleksij Rempel (4): dt-bindings: touchscreen: Convert resistive-adc-touch binding to json schema dt-bindings: touchscreen: add touchscreen-x/y-plate-ohms property dt-bindings: touchscreen: resistive-adc-touch: add support for z1 and z2 channels Input: resistive-adc-touch: add support for z1 and z2 channels .../input/touchscreen/resistive-adc-touch.txt | 33 ----- .../touchscreen/resistive-adc-touch.yaml | 86 +++++++++++ .../input/touchscreen/touchscreen.yaml | 6 + .../input/touchscreen/resistive-adc-touch.c | 140 ++++++++++++++++-- 4 files changed, 218 insertions(+), 47 deletions(-) delete mode 100644 Documentation/devicetree/bindings/input/touchscreen/resistive-adc-touch.txt create mode 100644 Documentation/devicetree/bindings/input/touchscreen/resistive-adc-touch.yaml -- 2.29.2 ``` ## \[PATCH v6 1/4\] dt-bindings: touchscreen: Convert resistive-adc-touch binding to json schema - From: Oleksij Rempel \ - Date: 2021-05-25 05:46:51 - Message: https://ratatoskr.run/linux-input/2021/05/1390797.md ```text Convert the resistive-adc-touch binding to DT schema format using json-schema. Signed-off-by: Oleksij Rempel Reviewed-by: Rob Herring Reviewed-by: Jonathan Cameron --- .../input/touchscreen/resistive-adc-touch.txt | 33 --------- .../touchscreen/resistive-adc-touch.yaml | 70 +++++++++++++++++++ 2 files changed, 70 insertions(+), 33 deletions(-) delete mode 100644 Documentation/devicetree/bindings/input/touchscreen/resistive-adc-touch.txt create mode 100644 Documentation/devicetree/bindings/input/touchscreen/resistive-adc-touch.yaml diff --git a/Documentation/devicetree/bindings/input/touchscreen/resistive-adc-touch.txt b/Documentation/devicetree/bindings/input/touchscreen/resistive-adc-touch.txt deleted file mode 100644 index af5223bb5bdd..000000000000 --- a/Documentation/devicetree/bindings/input/touchscreen/resistive-adc-touch.txt +++ /dev/null @@ -1,33 +0,0 @@ -Generic resistive touchscreen ADC - -Required properties: - - - compatible: must be "resistive-adc-touch" -The device must be connected to an ADC device that provides channels for -position measurement and optional pressure. -Refer to -https://github.com/devicetree-org/dt-schema/blob/master/schemas/iio/iio-consumer.yaml -for details - - - iio-channels: must have at least two channels connected to an ADC device. -These should correspond to the channels exposed by the ADC device and should -have the right index as the ADC device registers them. These channels -represent the relative position on the "x" and "y" axes. - - iio-channel-names: must have all the channels' names. Mandatory channels -are "x" and "y". - -Optional properties: - - iio-channels: The third channel named "pressure" is optional and can be -used if the ADC device also measures pressure besides position. -If this channel is missing, pressure will be ignored and the touchscreen -will only report position. - - iio-channel-names: optional channel named "pressure". - -Example: - - resistive_touch: resistive_touch { - compatible = "resistive-adc-touch"; - touchscreen-min-pressure = <50000>; - io-channels = <&adc 24>, <&adc 25>, <&adc 26>; - io-channel-names = "x", "y", "pressure"; - }; diff --git a/Documentation/devicetree/bindings/input/touchscreen/resistive-adc-touch.yaml b/Documentation/devicetree/bindings/input/touchscreen/resistive-adc-touch.yaml new file mode 100644 index 000000000000..38b4cbee9429 --- /dev/null +++ b/Documentation/devicetree/bindings/input/touchscreen/resistive-adc-touch.yaml @@ -0,0 +1,70 @@ +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/input/touchscreen/resistive-adc-touch.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Generic resistive touchscreen ADC + +maintainers: + - Oleksij Rempel + +description: | + Generic ADC based resistive touchscreen controller + The device must be connected to an ADC device that provides channels for + position measurement and optional pressure. + +allOf: + - $ref: touchscreen.yaml# + +properties: + compatible: + const: resistive-adc-touch + + io-channels: + minItems: 2 + items: + - description: x + - description: y + - description: pressure (optional) + + io-channel-names: + oneOf: + - items: + - enum: [x, y] + - enum: [x, y] + - items: + - enum: [x, y, pressure] + - enum: [x, y, pressure] + - enum: [x, y, pressure] + + touchscreen-size-x: true + touchscreen-size-y: true + touchscreen-fuzz-x: true + touchscreen-fuzz-y: true + touchscreen-inverted-x: true + touchscreen-inverted-y: true + touchscreen-swapped-x-y: true + touchscreen-min-pressure: true + +additionalProperties: false + +required: + - compatible + - io-channels + - io-channel-names + +examples: + - | + touchscreen { + compatible = "resistive-adc-touch"; + io-channels = <&adc 24>, <&adc 25>; + io-channel-names = "y", "x"; + }; + - | + touchscreen { + compatible = "resistive-adc-touch"; + touchscreen-min-pressure = <50000>; + io-channels = <&adc 24>, <&adc 25>, <&adc 26>; + io-channel-names = "y", "pressure", "x"; + }; -- 2.29.2 ``` ## \[PATCH v6 4/4\] Input: resistive-adc-touch: add support for z1 and z2 channels - From: Oleksij Rempel \ - Date: 2021-05-25 05:46:54 - Message: https://ratatoskr.run/linux-input/2021/05/1390799.md ```text This patch adds support for the z1 and z2 channels. These are used to calculate the applied pressure. As there is no common order of the individual channels of a resistive touch ADC, support for io-channel-names is added (although the DT bindings stated the driver already supports these). Signed-off-by: Oleksij Rempel Reviewed-by: Jonathan Cameron --- .../input/touchscreen/resistive-adc-touch.c | 140 ++++++++++++++++-- 1 file changed, 126 insertions(+), 14 deletions(-) diff --git a/drivers/input/touchscreen/resistive-adc-touch.c b/drivers/input/touchscreen/resistive-adc-touch.c index e50af30183f4..0939c0e97efb 100644 --- a/drivers/input/touchscreen/resistive-adc-touch.c +++ b/drivers/input/touchscreen/resistive-adc-touch.c @@ -20,7 +20,18 @@ #define DRIVER_NAME "resistive-adc-touch" #define GRTS_DEFAULT_PRESSURE_MIN 50000 +#define GRTS_DEFAULT_PRESSURE_MAX 65535 #define GRTS_MAX_POS_MASK GENMASK(11, 0) +#define GRTS_MAX_CHANNELS 4 + +enum grts_ch_type { + GRTS_CH_NONE = 0, + GRTS_CH_X, + GRTS_CH_Y, + GRTS_CH_PRESSURE, + GRTS_CH_Z1, + GRTS_CH_Z2, +}; /** * struct grts_state - generic resistive touch screen information struct @@ -33,24 +44,59 @@ */ struct grts_state { u32 pressure_min; + u32 x_plate_ohms; bool pressure; struct iio_channel *iio_chans; struct iio_cb_buffer *iio_cb; struct input_dev *input; struct touchscreen_properties prop; + u8 ch[GRTS_MAX_CHANNELS]; }; static int grts_cb(const void *data, void *private) { const u16 *touch_info = data; struct grts_state *st = private; - unsigned int x, y, press = 0x0; + unsigned int x, y, press = 0, z1 = 0, z2; + unsigned int Rt, i; + + for (i = 0; i < ARRAY_SIZE(st->ch) && st->ch[i] != GRTS_CH_NONE; i++) { + switch (st->ch[i]) { + case GRTS_CH_X: + x = touch_info[i]; + break; + case GRTS_CH_Y: + y = touch_info[i]; + break; + case GRTS_CH_PRESSURE: + press = touch_info[i]; + break; + case GRTS_CH_Z1: + z1 = touch_info[i]; + break; + case GRTS_CH_Z2: + z2 = touch_info[i]; + break; + } + } - /* channel data coming in buffer in the order below */ - x = touch_info[0]; - y = touch_info[1]; - if (st->pressure) - press = touch_info[2]; + if (z1) { + Rt = z2; + Rt -= z1; + Rt *= st->x_plate_ohms; + Rt = DIV_ROUND_CLOSEST(Rt, 16); + Rt *= x; + Rt /= z1; + Rt = DIV_ROUND_CLOSEST(Rt, 256); + /* + * On increased pressure the resistance (Rt) is decreasing + * so, convert values to make it looks as real pressure. + */ + if (Rt < GRTS_DEFAULT_PRESSURE_MAX) + press = GRTS_DEFAULT_PRESSURE_MAX - Rt; + else + press = 0; + } if ((!x && !y) || (st->pressure && (press < st->pressure_min))) { /* report end of touch */ @@ -94,12 +140,77 @@ static void grts_disable(void *data) iio_channel_release_all_cb(data); } +static int grts_get_properties(struct grts_state *st, struct device *dev) +{ + int idx, error; + + idx = device_property_match_string(dev, "io-channel-names", "x"); + if (idx < 0) + return idx; + + if (idx >= ARRAY_SIZE(st->ch)) + return -EOVERFLOW; + + st->ch[idx] = GRTS_CH_X; + + idx = device_property_match_string(dev, "io-channel-names", "y"); + if (idx < 0) + return idx; + + if (idx >= ARRAY_SIZE(st->ch)) + return -EOVERFLOW; + + st->ch[idx] = GRTS_CH_Y; + + /* pressure is optional */ + idx = device_property_match_string(dev, "io-channel-names", "pressure"); + if (idx >= 0) { + if (idx >= ARRAY_SIZE(st->ch)) + return -EOVERFLOW; + + st->ch[idx] = GRTS_CH_PRESSURE; + st->pressure = true; + + return 0; + } + + /* if no pressure is defined, try optional z1 + z2 */ + idx = device_property_match_string(dev, "io-channel-names", "z1"); + if (idx < 0) + return 0; + + if (idx >= ARRAY_SIZE(st->ch)) + return -EOVERFLOW; + + st->ch[idx] = GRTS_CH_Z1; + + /* if z1 is provided z2 is not optional */ + idx = device_property_match_string(dev, "io-channel-names", "z2"); + if (idx < 0) + return idx; + + if (idx >= ARRAY_SIZE(st->ch)) + return -EOVERFLOW; + + st->ch[idx] = GRTS_CH_Z2; + st->pressure = true; + + error = device_property_read_u32(dev, + "touchscreen-x-plate-ohms", + &st->x_plate_ohms); + if (error) { + dev_err(dev, "can't get touchscreen-x-plate-ohms property\n"); + return error; + } + + return 0; +} + static int grts_probe(struct platform_device *pdev) { struct grts_state *st; struct input_dev *input; struct device *dev = &pdev->dev; - struct iio_channel *chan; int error; st = devm_kzalloc(dev, sizeof(struct grts_state), GFP_KERNEL); @@ -115,12 +226,13 @@ static int grts_probe(struct platform_device *pdev) return error; } - chan = &st->iio_chans[0]; - st->pressure = false; - while (chan && chan->indio_dev) { - if (!strcmp(chan->channel->datasheet_name, "pressure")) - st->pressure = true; - chan++; + if (!device_property_present(dev, "io-channel-names")) + return -ENODEV; + + error = grts_get_properties(st, dev); + if (error) { + dev_err(dev, "Failed to parse properties\n"); + return error; } if (st->pressure) { @@ -148,7 +260,7 @@ static int grts_probe(struct platform_device *pdev) input_set_abs_params(input, ABS_Y, 0, GRTS_MAX_POS_MASK - 1, 0, 0); if (st->pressure) input_set_abs_params(input, ABS_PRESSURE, st->pressure_min, - 0xffff, 0, 0); + GRTS_DEFAULT_PRESSURE_MAX, 0, 0); input_set_capability(input, EV_KEY, BTN_TOUCH); -- 2.29.2 ``` ## \[PATCH v6 3/4\] dt-bindings: touchscreen: resistive-adc-touch: add support for z1 and z2 channels - From: Oleksij Rempel \ - Date: 2021-05-25 05:46:55 - Message: https://ratatoskr.run/linux-input/2021/05/1390798.md ```text For pressure calculation based on plates resistance we need some additional properties: - z1 and z2 channels with additional measurements between plates - actual resistance of the touchscreen. Currently we use only X-resistance. Signed-off-by: Oleksij Rempel Reviewed-by: Rob Herring --- .../input/touchscreen/resistive-adc-touch.yaml | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/Documentation/devicetree/bindings/input/touchscreen/resistive-adc-touch.yaml b/Documentation/devicetree/bindings/input/touchscreen/resistive-adc-touch.yaml index 38b4cbee9429..7fc22a403d48 100644 --- a/Documentation/devicetree/bindings/input/touchscreen/resistive-adc-touch.yaml +++ b/Documentation/devicetree/bindings/input/touchscreen/resistive-adc-touch.yaml @@ -27,6 +27,8 @@ properties: - description: x - description: y - description: pressure (optional) + - description: z1 (optional) + - description: z2 (optional) io-channel-names: oneOf: @@ -37,6 +39,11 @@ properties: - enum: [x, y, pressure] - enum: [x, y, pressure] - enum: [x, y, pressure] + - items: + - enum: [x, y, z1, z2] + - enum: [x, y, z1, z2] + - enum: [x, y, z1, z2] + - enum: [x, y, z1, z2] touchscreen-size-x: true touchscreen-size-y: true @@ -46,6 +53,7 @@ properties: touchscreen-inverted-y: true touchscreen-swapped-x-y: true touchscreen-min-pressure: true + touchscreen-x-plate-ohms: true additionalProperties: false @@ -68,3 +76,11 @@ examples: io-channels = <&adc 24>, <&adc 25>, <&adc 26>; io-channel-names = "y", "pressure", "x"; }; + - | + touchscreen { + compatible = "resistive-adc-touch"; + touchscreen-min-pressure = <50000>; + io-channels = <&adc 1>, <&adc 2>, <&adc 3>, <&adc 4>; + io-channel-names = "x", "z1", "z2", "y"; + touchscreen-x-plate-ohms = <800>; + }; -- 2.29.2 ``` ## \[PATCH v6 2/4\] dt-bindings: touchscreen: add touchscreen-x/y-plate-ohms property - From: Oleksij Rempel \ - Date: 2021-05-25 05:46:57 - Message: https://ratatoskr.run/linux-input/2021/05/1390800.md ```text Te calculate the pressure on a restrictive touchscreen we need need to know resistance at least of X plate. Some calculations need to use both X and Y values. So, add generic properties which can be used by all drivers Signed-off-by: Oleksij Rempel Reviewed-by: Rob Herring --- .../devicetree/bindings/input/touchscreen/touchscreen.yaml | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/Documentation/devicetree/bindings/input/touchscreen/touchscreen.yaml b/Documentation/devicetree/bindings/input/touchscreen/touchscreen.yaml index 057e1063759c..2d7b039ce47f 100644 --- a/Documentation/devicetree/bindings/input/touchscreen/touchscreen.yaml +++ b/Documentation/devicetree/bindings/input/touchscreen/touchscreen.yaml @@ -77,6 +77,12 @@ properties: touchscreen-y-mm: description: vertical length in mm of the touchscreen + touchscreen-x-plate-ohms: + description: Resistance of the X-plate in Ohms + + touchscreen-y-plate-ohms: + description: Resistance of the Y-plate in Ohms + dependencies: touchscreen-size-x: [ touchscreen-size-y ] touchscreen-size-y: [ touchscreen-size-x ] -- 2.29.2 ``` ## Re: \[PATCH v6 0/4\] add z1 and z2 channels support for resistive-adc-touch driver - From: Dmitry Torokhov \ - Date: 2021-05-25 20:06:29 - Message: https://ratatoskr.run/linux-input/2021/05/1391807.md ```text Hi Oleksij, On Tue, May 25, 2021 at 07:46:30AM +0200, Oleksij Rempel wrote: > changes v6: > - drop other DT changes > - add more Reviewed-by tags > - remove redundant GRTS_CH_NONE check Applied the lot, thank you. -- Dmitry ``` ## Re: \[PATCH v6 0/4\] add z1 and z2 channels support for resistive-adc-touch driver - From: \ - Date: 2021-06-02 11:15:55 - Message: https://ratatoskr.run/linux-input/2021/06/1399714.md ```text On 5/25/21 8:46 AM, Oleksij Rempel wrote: > changes v6: > - drop other DT changes > - add more Reviewed-by tags > - remove redundant GRTS_CH_NONE check > > changes v5: > - fix validate for other DT examples. > - add Reviewed-by: Rob Herring [ref] to some of the patches > > changes v4: > - resistive-adc-touch: remove unused variable > > changes v3: > - yaml: fix validation for channel names > - yaml: add nodename validation > > changes v2: > - add yaml conversion patch to this series > - reword commit message for the last patch > - fix possible overflow on the buffer dispatcher > > Oleksij Rempel (4): > dt-bindings: touchscreen: Convert resistive-adc-touch binding to json > schema > dt-bindings: touchscreen: add touchscreen-x/y-plate-ohms property > dt-bindings: touchscreen: resistive-adc-touch: add support for z1 and > z2 channels > Input: resistive-adc-touch: add support for z1 and z2 channels > > .../input/touchscreen/resistive-adc-touch.txt | 33 ----- > .../touchscreen/resistive-adc-touch.yaml | 86 +++++++++++ > .../input/touchscreen/touchscreen.yaml | 6 + > .../input/touchscreen/resistive-adc-touch.c | 140 ++++++++++++++++-- > 4 files changed, 218 insertions(+), 47 deletions(-) > delete mode 100644 Documentation/devicetree/bindings/input/touchscreen/resistive-adc-touch.txt > create mode 100644 Documentation/devicetree/bindings/input/touchscreen/resistive-adc-touch.yaml > > -- > 2.29.2 > Hello Oleksij, As I am listed in the MAINTAINERS file for this driver, why I am not even CC-ed to this patch series ? At least what I could have done is test this series on my board using this driver. Eugen ``` ## Re: \[PATCH v6 0/4\] add z1 and z2 channels support for resistive-adc-touch driver - From: Oleksij Rempel \ - Date: 2021-06-07 09:22:44 - Message: https://ratatoskr.run/linux-input/2021/06/1404540.md ```text Hello Eugen, On Wed, Jun 02, 2021 at 11:15:47AM +0000, Eugen.Hristev@microchip.com wrote: > On 5/25/21 8:46 AM, Oleksij Rempel wrote: > > changes v6: > > - drop other DT changes > > - add more Reviewed-by tags > > - remove redundant GRTS_CH_NONE check > > > > changes v5: > > - fix validate for other DT examples. > > - add Reviewed-by: Rob Herring [ref] to some of the patches > > > > changes v4: > > - resistive-adc-touch: remove unused variable > > > > changes v3: > > - yaml: fix validation for channel names > > - yaml: add nodename validation > > > > changes v2: > > - add yaml conversion patch to this series > > - reword commit message for the last patch > > - fix possible overflow on the buffer dispatcher > > > > Oleksij Rempel (4): > > dt-bindings: touchscreen: Convert resistive-adc-touch binding to json > > schema > > dt-bindings: touchscreen: add touchscreen-x/y-plate-ohms property > > dt-bindings: touchscreen: resistive-adc-touch: add support for z1 and > > z2 channels > > Input: resistive-adc-touch: add support for z1 and z2 channels > > > > .../input/touchscreen/resistive-adc-touch.txt | 33 ----- > > .../touchscreen/resistive-adc-touch.yaml | 86 +++++++++++ > > .../input/touchscreen/touchscreen.yaml | 6 + > > .../input/touchscreen/resistive-adc-touch.c | 140 ++++++++++++++++-- > > 4 files changed, 218 insertions(+), 47 deletions(-) > > delete mode 100644 Documentation/devicetree/bindings/input/touchscreen/resistive-adc-touch.txt > > create mode 100644 Documentation/devicetree/bindings/input/touchscreen/resistive-adc-touch.yaml > > > > -- > > 2.29.2 > > > > > > Hello Oleksij, > > As I am listed in the MAINTAINERS file for this driver, why I am not > even CC-ed to this patch series ? Sorry, I missed you by accident. Beside, you are not listed as maintainer for the: Documentation/devicetree/bindings/input/touchscreen/resistive-adc-touch.* > At least what I could have done is test this series on my board using > this driver. Do you have some regressions with it? Regards, Oleksij -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | ```