Googler | 9398cc3 | 2022-12-02 17:21:52 +0800 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0-only |
Googler | af606d2 | 2022-10-26 21:40:12 -0700 | [diff] [blame] | 2 | /* |
| 3 | * Generic DT helper functions for touchscreen devices |
| 4 | * |
| 5 | * Copyright (c) 2014 Sebastian Reichel <sre@kernel.org> |
| 6 | */ |
| 7 | |
| 8 | #include <linux/property.h> |
| 9 | #include <linux/input.h> |
| 10 | #include <linux/input/mt.h> |
| 11 | #include <linux/input/touchscreen.h> |
Googler | 9398cc3 | 2022-12-02 17:21:52 +0800 | [diff] [blame] | 12 | #include <linux/module.h> |
Googler | af606d2 | 2022-10-26 21:40:12 -0700 | [diff] [blame] | 13 | |
| 14 | static bool touchscreen_get_prop_u32(struct device *dev, |
| 15 | const char *property, |
| 16 | unsigned int default_value, |
| 17 | unsigned int *value) |
| 18 | { |
| 19 | u32 val; |
| 20 | int error; |
| 21 | |
| 22 | error = device_property_read_u32(dev, property, &val); |
| 23 | if (error) { |
| 24 | *value = default_value; |
| 25 | return false; |
| 26 | } |
| 27 | |
| 28 | *value = val; |
| 29 | return true; |
| 30 | } |
| 31 | |
| 32 | static void touchscreen_set_params(struct input_dev *dev, |
| 33 | unsigned long axis, |
Googler | 9398cc3 | 2022-12-02 17:21:52 +0800 | [diff] [blame] | 34 | int min, int max, int fuzz) |
Googler | af606d2 | 2022-10-26 21:40:12 -0700 | [diff] [blame] | 35 | { |
| 36 | struct input_absinfo *absinfo; |
| 37 | |
| 38 | if (!test_bit(axis, dev->absbit)) { |
| 39 | dev_warn(&dev->dev, |
| 40 | "DT specifies parameters but the axis %lu is not set up\n", |
| 41 | axis); |
| 42 | return; |
| 43 | } |
| 44 | |
| 45 | absinfo = &dev->absinfo[axis]; |
Googler | 9398cc3 | 2022-12-02 17:21:52 +0800 | [diff] [blame] | 46 | absinfo->minimum = min; |
Googler | af606d2 | 2022-10-26 21:40:12 -0700 | [diff] [blame] | 47 | absinfo->maximum = max; |
| 48 | absinfo->fuzz = fuzz; |
| 49 | } |
| 50 | |
| 51 | /** |
| 52 | * touchscreen_parse_properties - parse common touchscreen DT properties |
| 53 | * @input: input device that should be parsed |
| 54 | * @multitouch: specifies whether parsed properties should be applied to |
| 55 | * single-touch or multi-touch axes |
| 56 | * @prop: pointer to a struct touchscreen_properties into which to store |
| 57 | * axis swap and invert info for use with touchscreen_report_x_y(); |
| 58 | * or %NULL |
| 59 | * |
| 60 | * This function parses common DT properties for touchscreens and setups the |
| 61 | * input device accordingly. The function keeps previously set up default |
| 62 | * values if no value is specified via DT. |
| 63 | */ |
| 64 | void touchscreen_parse_properties(struct input_dev *input, bool multitouch, |
| 65 | struct touchscreen_properties *prop) |
| 66 | { |
| 67 | struct device *dev = input->dev.parent; |
Googler | 9398cc3 | 2022-12-02 17:21:52 +0800 | [diff] [blame] | 68 | struct input_absinfo *absinfo; |
Googler | af606d2 | 2022-10-26 21:40:12 -0700 | [diff] [blame] | 69 | unsigned int axis; |
Googler | 9398cc3 | 2022-12-02 17:21:52 +0800 | [diff] [blame] | 70 | unsigned int minimum, maximum, fuzz; |
Googler | af606d2 | 2022-10-26 21:40:12 -0700 | [diff] [blame] | 71 | bool data_present; |
| 72 | |
| 73 | input_alloc_absinfo(input); |
| 74 | if (!input->absinfo) |
| 75 | return; |
| 76 | |
| 77 | axis = multitouch ? ABS_MT_POSITION_X : ABS_X; |
Googler | 9398cc3 | 2022-12-02 17:21:52 +0800 | [diff] [blame] | 78 | data_present = touchscreen_get_prop_u32(dev, "touchscreen-min-x", |
| 79 | input_abs_get_min(input, axis), |
Googler | b48fa91 | 2023-03-17 12:40:29 +0530 | [diff] [blame^] | 80 | &minimum) | |
| 81 | touchscreen_get_prop_u32(dev, "touchscreen-size-x", |
Googler | af606d2 | 2022-10-26 21:40:12 -0700 | [diff] [blame] | 82 | input_abs_get_max(input, |
| 83 | axis) + 1, |
Googler | b48fa91 | 2023-03-17 12:40:29 +0530 | [diff] [blame^] | 84 | &maximum) | |
| 85 | touchscreen_get_prop_u32(dev, "touchscreen-fuzz-x", |
Googler | af606d2 | 2022-10-26 21:40:12 -0700 | [diff] [blame] | 86 | input_abs_get_fuzz(input, axis), |
| 87 | &fuzz); |
| 88 | if (data_present) |
Googler | 9398cc3 | 2022-12-02 17:21:52 +0800 | [diff] [blame] | 89 | touchscreen_set_params(input, axis, minimum, maximum - 1, fuzz); |
Googler | af606d2 | 2022-10-26 21:40:12 -0700 | [diff] [blame] | 90 | |
| 91 | axis = multitouch ? ABS_MT_POSITION_Y : ABS_Y; |
Googler | 9398cc3 | 2022-12-02 17:21:52 +0800 | [diff] [blame] | 92 | data_present = touchscreen_get_prop_u32(dev, "touchscreen-min-y", |
| 93 | input_abs_get_min(input, axis), |
Googler | b48fa91 | 2023-03-17 12:40:29 +0530 | [diff] [blame^] | 94 | &minimum) | |
| 95 | touchscreen_get_prop_u32(dev, "touchscreen-size-y", |
Googler | af606d2 | 2022-10-26 21:40:12 -0700 | [diff] [blame] | 96 | input_abs_get_max(input, |
| 97 | axis) + 1, |
Googler | b48fa91 | 2023-03-17 12:40:29 +0530 | [diff] [blame^] | 98 | &maximum) | |
| 99 | touchscreen_get_prop_u32(dev, "touchscreen-fuzz-y", |
Googler | af606d2 | 2022-10-26 21:40:12 -0700 | [diff] [blame] | 100 | input_abs_get_fuzz(input, axis), |
| 101 | &fuzz); |
| 102 | if (data_present) |
Googler | 9398cc3 | 2022-12-02 17:21:52 +0800 | [diff] [blame] | 103 | touchscreen_set_params(input, axis, minimum, maximum - 1, fuzz); |
Googler | af606d2 | 2022-10-26 21:40:12 -0700 | [diff] [blame] | 104 | |
| 105 | axis = multitouch ? ABS_MT_PRESSURE : ABS_PRESSURE; |
| 106 | data_present = touchscreen_get_prop_u32(dev, |
| 107 | "touchscreen-max-pressure", |
| 108 | input_abs_get_max(input, axis), |
Googler | b48fa91 | 2023-03-17 12:40:29 +0530 | [diff] [blame^] | 109 | &maximum) | |
| 110 | touchscreen_get_prop_u32(dev, |
| 111 | "touchscreen-fuzz-pressure", |
| 112 | input_abs_get_fuzz(input, axis), |
| 113 | &fuzz); |
Googler | af606d2 | 2022-10-26 21:40:12 -0700 | [diff] [blame] | 114 | if (data_present) |
Googler | 9398cc3 | 2022-12-02 17:21:52 +0800 | [diff] [blame] | 115 | touchscreen_set_params(input, axis, 0, maximum, fuzz); |
Googler | af606d2 | 2022-10-26 21:40:12 -0700 | [diff] [blame] | 116 | |
| 117 | if (!prop) |
| 118 | return; |
| 119 | |
| 120 | axis = multitouch ? ABS_MT_POSITION_X : ABS_X; |
| 121 | |
| 122 | prop->max_x = input_abs_get_max(input, axis); |
| 123 | prop->max_y = input_abs_get_max(input, axis + 1); |
Googler | 9398cc3 | 2022-12-02 17:21:52 +0800 | [diff] [blame] | 124 | |
Googler | af606d2 | 2022-10-26 21:40:12 -0700 | [diff] [blame] | 125 | prop->invert_x = |
| 126 | device_property_read_bool(dev, "touchscreen-inverted-x"); |
Googler | 9398cc3 | 2022-12-02 17:21:52 +0800 | [diff] [blame] | 127 | if (prop->invert_x) { |
| 128 | absinfo = &input->absinfo[axis]; |
| 129 | absinfo->maximum -= absinfo->minimum; |
| 130 | absinfo->minimum = 0; |
| 131 | } |
| 132 | |
Googler | af606d2 | 2022-10-26 21:40:12 -0700 | [diff] [blame] | 133 | prop->invert_y = |
| 134 | device_property_read_bool(dev, "touchscreen-inverted-y"); |
Googler | 9398cc3 | 2022-12-02 17:21:52 +0800 | [diff] [blame] | 135 | if (prop->invert_y) { |
| 136 | absinfo = &input->absinfo[axis + 1]; |
| 137 | absinfo->maximum -= absinfo->minimum; |
| 138 | absinfo->minimum = 0; |
| 139 | } |
| 140 | |
Googler | af606d2 | 2022-10-26 21:40:12 -0700 | [diff] [blame] | 141 | prop->swap_x_y = |
| 142 | device_property_read_bool(dev, "touchscreen-swapped-x-y"); |
| 143 | if (prop->swap_x_y) |
| 144 | swap(input->absinfo[axis], input->absinfo[axis + 1]); |
| 145 | } |
| 146 | EXPORT_SYMBOL(touchscreen_parse_properties); |
| 147 | |
| 148 | static void |
| 149 | touchscreen_apply_prop_to_x_y(const struct touchscreen_properties *prop, |
| 150 | unsigned int *x, unsigned int *y) |
| 151 | { |
| 152 | if (prop->invert_x) |
| 153 | *x = prop->max_x - *x; |
| 154 | |
| 155 | if (prop->invert_y) |
| 156 | *y = prop->max_y - *y; |
| 157 | |
| 158 | if (prop->swap_x_y) |
| 159 | swap(*x, *y); |
| 160 | } |
| 161 | |
| 162 | /** |
| 163 | * touchscreen_set_mt_pos - Set input_mt_pos coordinates |
| 164 | * @pos: input_mt_pos to set coordinates of |
| 165 | * @prop: pointer to a struct touchscreen_properties |
| 166 | * @x: X coordinate to store in pos |
| 167 | * @y: Y coordinate to store in pos |
| 168 | * |
| 169 | * Adjust the passed in x and y values applying any axis inversion and |
| 170 | * swapping requested in the passed in touchscreen_properties and store |
| 171 | * the result in a struct input_mt_pos. |
| 172 | */ |
| 173 | void touchscreen_set_mt_pos(struct input_mt_pos *pos, |
| 174 | const struct touchscreen_properties *prop, |
| 175 | unsigned int x, unsigned int y) |
| 176 | { |
| 177 | touchscreen_apply_prop_to_x_y(prop, &x, &y); |
| 178 | pos->x = x; |
| 179 | pos->y = y; |
| 180 | } |
| 181 | EXPORT_SYMBOL(touchscreen_set_mt_pos); |
| 182 | |
| 183 | /** |
| 184 | * touchscreen_report_pos - Report touchscreen coordinates |
| 185 | * @input: input_device to report coordinates for |
| 186 | * @prop: pointer to a struct touchscreen_properties |
| 187 | * @x: X coordinate to report |
| 188 | * @y: Y coordinate to report |
| 189 | * @multitouch: Report coordinates on single-touch or multi-touch axes |
| 190 | * |
| 191 | * Adjust the passed in x and y values applying any axis inversion and |
| 192 | * swapping requested in the passed in touchscreen_properties and then |
| 193 | * report the resulting coordinates on the input_dev's x and y axis. |
| 194 | */ |
| 195 | void touchscreen_report_pos(struct input_dev *input, |
| 196 | const struct touchscreen_properties *prop, |
| 197 | unsigned int x, unsigned int y, |
| 198 | bool multitouch) |
| 199 | { |
| 200 | touchscreen_apply_prop_to_x_y(prop, &x, &y); |
| 201 | input_report_abs(input, multitouch ? ABS_MT_POSITION_X : ABS_X, x); |
| 202 | input_report_abs(input, multitouch ? ABS_MT_POSITION_Y : ABS_Y, y); |
| 203 | } |
| 204 | EXPORT_SYMBOL(touchscreen_report_pos); |
Googler | 9398cc3 | 2022-12-02 17:21:52 +0800 | [diff] [blame] | 205 | |
| 206 | MODULE_LICENSE("GPL v2"); |
| 207 | MODULE_DESCRIPTION("Device-tree helpers functions for touchscreen devices"); |