Nicolas Saenz Julienne | 0b9f28f | 2018-12-21 00:47:40 -0800 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | /* |
| 3 | * Raspberry Pi firmware based touchscreen driver |
| 4 | * |
| 5 | * Copyright (C) 2015, 2017 Raspberry Pi |
| 6 | * Copyright (C) 2018 Nicolas Saenz Julienne <nsaenzjulienne@suse.de> |
| 7 | */ |
| 8 | |
| 9 | #include <linux/io.h> |
| 10 | #include <linux/of.h> |
| 11 | #include <linux/slab.h> |
| 12 | #include <linux/device.h> |
| 13 | #include <linux/module.h> |
| 14 | #include <linux/bitops.h> |
| 15 | #include <linux/dma-mapping.h> |
| 16 | #include <linux/platform_device.h> |
| 17 | #include <linux/input.h> |
| 18 | #include <linux/input/mt.h> |
| 19 | #include <linux/input-polldev.h> |
| 20 | #include <linux/input/touchscreen.h> |
| 21 | #include <soc/bcm2835/raspberrypi-firmware.h> |
| 22 | |
| 23 | #define RPI_TS_DEFAULT_WIDTH 800 |
| 24 | #define RPI_TS_DEFAULT_HEIGHT 480 |
| 25 | |
| 26 | #define RPI_TS_MAX_SUPPORTED_POINTS 10 |
| 27 | |
| 28 | #define RPI_TS_FTS_TOUCH_DOWN 0 |
| 29 | #define RPI_TS_FTS_TOUCH_CONTACT 2 |
| 30 | |
| 31 | #define RPI_TS_POLL_INTERVAL 17 /* 60fps */ |
| 32 | |
| 33 | #define RPI_TS_NPOINTS_REG_INVALIDATE 99 |
| 34 | |
| 35 | struct rpi_ts { |
| 36 | struct platform_device *pdev; |
| 37 | struct input_polled_dev *poll_dev; |
| 38 | struct touchscreen_properties prop; |
| 39 | |
| 40 | void __iomem *fw_regs_va; |
| 41 | dma_addr_t fw_regs_phys; |
| 42 | |
| 43 | int known_ids; |
| 44 | }; |
| 45 | |
| 46 | struct rpi_ts_regs { |
| 47 | u8 device_mode; |
| 48 | u8 gesture_id; |
| 49 | u8 num_points; |
| 50 | struct rpi_ts_touch { |
| 51 | u8 xh; |
| 52 | u8 xl; |
| 53 | u8 yh; |
| 54 | u8 yl; |
| 55 | u8 pressure; /* Not supported */ |
| 56 | u8 area; /* Not supported */ |
| 57 | } point[RPI_TS_MAX_SUPPORTED_POINTS]; |
| 58 | }; |
| 59 | |
| 60 | static void rpi_ts_poll(struct input_polled_dev *dev) |
| 61 | { |
| 62 | struct input_dev *input = dev->input; |
| 63 | struct rpi_ts *ts = dev->private; |
| 64 | struct rpi_ts_regs regs; |
| 65 | int modified_ids = 0; |
| 66 | long released_ids; |
| 67 | int event_type; |
| 68 | int touchid; |
| 69 | int x, y; |
| 70 | int i; |
| 71 | |
| 72 | memcpy_fromio(®s, ts->fw_regs_va, sizeof(regs)); |
| 73 | /* |
| 74 | * We poll the memory based register copy of the touchscreen chip using |
| 75 | * the number of points register to know whether the copy has been |
| 76 | * updated (we write 99 to the memory copy, the GPU will write between |
| 77 | * 0 - 10 points) |
| 78 | */ |
| 79 | iowrite8(RPI_TS_NPOINTS_REG_INVALIDATE, |
| 80 | ts->fw_regs_va + offsetof(struct rpi_ts_regs, num_points)); |
| 81 | |
| 82 | if (regs.num_points == RPI_TS_NPOINTS_REG_INVALIDATE || |
| 83 | (regs.num_points == 0 && ts->known_ids == 0)) |
| 84 | return; |
| 85 | |
| 86 | for (i = 0; i < regs.num_points; i++) { |
| 87 | x = (((int)regs.point[i].xh & 0xf) << 8) + regs.point[i].xl; |
| 88 | y = (((int)regs.point[i].yh & 0xf) << 8) + regs.point[i].yl; |
| 89 | touchid = (regs.point[i].yh >> 4) & 0xf; |
| 90 | event_type = (regs.point[i].xh >> 6) & 0x03; |
| 91 | |
| 92 | modified_ids |= BIT(touchid); |
| 93 | |
| 94 | if (event_type == RPI_TS_FTS_TOUCH_DOWN || |
| 95 | event_type == RPI_TS_FTS_TOUCH_CONTACT) { |
| 96 | input_mt_slot(input, touchid); |
| 97 | input_mt_report_slot_state(input, MT_TOOL_FINGER, 1); |
| 98 | touchscreen_report_pos(input, &ts->prop, x, y, true); |
| 99 | } |
| 100 | } |
| 101 | |
| 102 | released_ids = ts->known_ids & ~modified_ids; |
| 103 | for_each_set_bit(i, &released_ids, RPI_TS_MAX_SUPPORTED_POINTS) { |
| 104 | input_mt_slot(input, i); |
| 105 | input_mt_report_slot_state(input, MT_TOOL_FINGER, 0); |
| 106 | modified_ids &= ~(BIT(i)); |
| 107 | } |
| 108 | ts->known_ids = modified_ids; |
| 109 | |
| 110 | input_mt_sync_frame(input); |
| 111 | input_sync(input); |
| 112 | } |
| 113 | |
| 114 | static void rpi_ts_dma_cleanup(void *data) |
| 115 | { |
| 116 | struct rpi_ts *ts = data; |
| 117 | struct device *dev = &ts->pdev->dev; |
| 118 | |
| 119 | dma_free_coherent(dev, PAGE_SIZE, ts->fw_regs_va, ts->fw_regs_phys); |
| 120 | } |
| 121 | |
| 122 | static int rpi_ts_probe(struct platform_device *pdev) |
| 123 | { |
| 124 | struct device *dev = &pdev->dev; |
| 125 | struct device_node *np = dev->of_node; |
| 126 | struct input_polled_dev *poll_dev; |
| 127 | struct device_node *fw_node; |
| 128 | struct rpi_firmware *fw; |
| 129 | struct input_dev *input; |
| 130 | struct rpi_ts *ts; |
| 131 | u32 touchbuf; |
| 132 | int error; |
| 133 | |
| 134 | fw_node = of_get_parent(np); |
| 135 | if (!fw_node) { |
| 136 | dev_err(dev, "Missing firmware node\n"); |
| 137 | return -ENOENT; |
| 138 | } |
| 139 | |
| 140 | fw = rpi_firmware_get(fw_node); |
| 141 | of_node_put(fw_node); |
| 142 | if (!fw) |
| 143 | return -EPROBE_DEFER; |
| 144 | |
| 145 | ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL); |
| 146 | if (!ts) |
| 147 | return -ENOMEM; |
| 148 | ts->pdev = pdev; |
| 149 | |
Luis Chamberlain | 750afb0 | 2019-01-04 09:23:09 +0100 | [diff] [blame^] | 150 | ts->fw_regs_va = dma_alloc_coherent(dev, PAGE_SIZE, &ts->fw_regs_phys, |
| 151 | GFP_KERNEL); |
Nicolas Saenz Julienne | 0b9f28f | 2018-12-21 00:47:40 -0800 | [diff] [blame] | 152 | if (!ts->fw_regs_va) { |
| 153 | dev_err(dev, "failed to dma_alloc_coherent\n"); |
| 154 | return -ENOMEM; |
| 155 | } |
| 156 | |
| 157 | error = devm_add_action_or_reset(dev, rpi_ts_dma_cleanup, ts); |
| 158 | if (error) { |
| 159 | dev_err(dev, "failed to devm_add_action_or_reset, %d\n", error); |
| 160 | return error; |
| 161 | } |
| 162 | |
| 163 | |
| 164 | touchbuf = (u32)ts->fw_regs_phys; |
| 165 | error = rpi_firmware_property(fw, RPI_FIRMWARE_FRAMEBUFFER_SET_TOUCHBUF, |
| 166 | &touchbuf, sizeof(touchbuf)); |
| 167 | |
| 168 | if (error || touchbuf != 0) { |
| 169 | dev_warn(dev, "Failed to set touchbuf, %d\n", error); |
| 170 | return error; |
| 171 | } |
| 172 | |
| 173 | poll_dev = devm_input_allocate_polled_device(dev); |
| 174 | if (!poll_dev) { |
| 175 | dev_err(dev, "Failed to allocate input device\n"); |
| 176 | return -ENOMEM; |
| 177 | } |
| 178 | ts->poll_dev = poll_dev; |
| 179 | input = poll_dev->input; |
| 180 | |
| 181 | input->name = "raspberrypi-ts"; |
| 182 | input->id.bustype = BUS_HOST; |
| 183 | poll_dev->poll_interval = RPI_TS_POLL_INTERVAL; |
| 184 | poll_dev->poll = rpi_ts_poll; |
| 185 | poll_dev->private = ts; |
| 186 | |
| 187 | input_set_abs_params(input, ABS_MT_POSITION_X, 0, |
| 188 | RPI_TS_DEFAULT_WIDTH, 0, 0); |
| 189 | input_set_abs_params(input, ABS_MT_POSITION_Y, 0, |
| 190 | RPI_TS_DEFAULT_HEIGHT, 0, 0); |
| 191 | touchscreen_parse_properties(input, true, &ts->prop); |
| 192 | |
| 193 | error = input_mt_init_slots(input, RPI_TS_MAX_SUPPORTED_POINTS, |
| 194 | INPUT_MT_DIRECT); |
| 195 | if (error) { |
| 196 | dev_err(dev, "could not init mt slots, %d\n", error); |
| 197 | return error; |
| 198 | } |
| 199 | |
| 200 | error = input_register_polled_device(poll_dev); |
| 201 | if (error) { |
| 202 | dev_err(dev, "could not register input device, %d\n", error); |
| 203 | return error; |
| 204 | } |
| 205 | |
| 206 | return 0; |
| 207 | } |
| 208 | |
| 209 | static const struct of_device_id rpi_ts_match[] = { |
| 210 | { .compatible = "raspberrypi,firmware-ts", }, |
| 211 | {}, |
| 212 | }; |
| 213 | MODULE_DEVICE_TABLE(of, rpi_ts_match); |
| 214 | |
| 215 | static struct platform_driver rpi_ts_driver = { |
| 216 | .driver = { |
| 217 | .name = "raspberrypi-ts", |
| 218 | .of_match_table = rpi_ts_match, |
| 219 | }, |
| 220 | .probe = rpi_ts_probe, |
| 221 | }; |
| 222 | module_platform_driver(rpi_ts_driver); |
| 223 | |
| 224 | MODULE_AUTHOR("Gordon Hollingworth"); |
| 225 | MODULE_AUTHOR("Nicolas Saenz Julienne <nsaenzjulienne@suse.de>"); |
| 226 | MODULE_DESCRIPTION("Raspberry Pi firmware based touchscreen driver"); |
| 227 | MODULE_LICENSE("GPL v2"); |