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/touchscreen.h> 20 #include <soc/bcm2835/raspberrypi-firmware.h> 21 22 #define RPI_TS_DEFAULT_WIDTH 800 23 #define RPI_TS_DEFAULT_HEIGHT 480 24 25 #define RPI_TS_MAX_SUPPORTED_POINTS 10 26 27 #define RPI_TS_FTS_TOUCH_DOWN 0 28 #define RPI_TS_FTS_TOUCH_CONTACT 2 29 30 #define RPI_TS_POLL_INTERVAL 17 /* 60fps */ 31 32 #define RPI_TS_NPOINTS_REG_INVALIDATE 99 33 34 struct rpi_ts { 35 struct platform_device *pdev; 36 struct input_dev *input; 37 struct touchscreen_properties prop; 38 39 void __iomem *fw_regs_va; 40 dma_addr_t fw_regs_phys; 41 42 int known_ids; 43 }; 44 45 struct rpi_ts_regs { 46 u8 device_mode; 47 u8 gesture_id; 48 u8 num_points; 49 struct rpi_ts_touch { 50 u8 xh; 51 u8 xl; 52 u8 yh; 53 u8 yl; 54 u8 pressure; /* Not supported */ 55 u8 area; /* Not supported */ 56 } point[RPI_TS_MAX_SUPPORTED_POINTS]; 57 }; 58 59 static void rpi_ts_poll(struct input_dev *input) 60 { 61 struct rpi_ts *ts = input_get_drvdata(input); 62 struct rpi_ts_regs regs; 63 int modified_ids = 0; 64 long released_ids; 65 int event_type; 66 int touchid; 67 int x, y; 68 int i; 69 70 memcpy_fromio(®s, ts->fw_regs_va, sizeof(regs)); 71 /* 72 * We poll the memory based register copy of the touchscreen chip using 73 * the number of points register to know whether the copy has been 74 * updated (we write 99 to the memory copy, the GPU will write between 75 * 0 - 10 points) 76 */ 77 iowrite8(RPI_TS_NPOINTS_REG_INVALIDATE, 78 ts->fw_regs_va + offsetof(struct rpi_ts_regs, num_points)); 79 80 if (regs.num_points == RPI_TS_NPOINTS_REG_INVALIDATE || 81 (regs.num_points == 0 && ts->known_ids == 0)) 82 return; 83 84 for (i = 0; i < regs.num_points; i++) { 85 x = (((int)regs.point[i].xh & 0xf) << 8) + regs.point[i].xl; 86 y = (((int)regs.point[i].yh & 0xf) << 8) + regs.point[i].yl; 87 touchid = (regs.point[i].yh >> 4) & 0xf; 88 event_type = (regs.point[i].xh >> 6) & 0x03; 89 90 modified_ids |= BIT(touchid); 91 92 if (event_type == RPI_TS_FTS_TOUCH_DOWN || 93 event_type == RPI_TS_FTS_TOUCH_CONTACT) { 94 input_mt_slot(input, touchid); 95 input_mt_report_slot_state(input, MT_TOOL_FINGER, 1); 96 touchscreen_report_pos(input, &ts->prop, x, y, true); 97 } 98 } 99 100 released_ids = ts->known_ids & ~modified_ids; 101 for_each_set_bit(i, &released_ids, RPI_TS_MAX_SUPPORTED_POINTS) { 102 input_mt_slot(input, i); 103 input_mt_report_slot_inactive(input); 104 modified_ids &= ~(BIT(i)); 105 } 106 ts->known_ids = modified_ids; 107 108 input_mt_sync_frame(input); 109 input_sync(input); 110 } 111 112 static void rpi_ts_dma_cleanup(void *data) 113 { 114 struct rpi_ts *ts = data; 115 struct device *dev = &ts->pdev->dev; 116 117 dma_free_coherent(dev, PAGE_SIZE, ts->fw_regs_va, ts->fw_regs_phys); 118 } 119 120 static int rpi_ts_probe(struct platform_device *pdev) 121 { 122 struct device *dev = &pdev->dev; 123 struct device_node *np = dev->of_node; 124 struct input_dev *input; 125 struct device_node *fw_node; 126 struct rpi_firmware *fw; 127 struct rpi_ts *ts; 128 u32 touchbuf; 129 int error; 130 131 fw_node = of_get_parent(np); 132 if (!fw_node) { 133 dev_err(dev, "Missing firmware node\n"); 134 return -ENOENT; 135 } 136 137 fw = devm_rpi_firmware_get(&pdev->dev, fw_node); 138 of_node_put(fw_node); 139 if (!fw) 140 return -EPROBE_DEFER; 141 142 ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL); 143 if (!ts) 144 return -ENOMEM; 145 ts->pdev = pdev; 146 147 ts->fw_regs_va = dma_alloc_coherent(dev, PAGE_SIZE, &ts->fw_regs_phys, 148 GFP_KERNEL); 149 if (!ts->fw_regs_va) { 150 dev_err(dev, "failed to dma_alloc_coherent\n"); 151 return -ENOMEM; 152 } 153 154 error = devm_add_action_or_reset(dev, rpi_ts_dma_cleanup, ts); 155 if (error) { 156 dev_err(dev, "failed to devm_add_action_or_reset, %d\n", error); 157 return error; 158 } 159 160 touchbuf = (u32)ts->fw_regs_phys; 161 error = rpi_firmware_property(fw, RPI_FIRMWARE_FRAMEBUFFER_SET_TOUCHBUF, 162 &touchbuf, sizeof(touchbuf)); 163 if (error || touchbuf != 0) { 164 dev_warn(dev, "Failed to set touchbuf, %d\n", error); 165 return error; 166 } 167 168 input = devm_input_allocate_device(dev); 169 if (!input) { 170 dev_err(dev, "Failed to allocate input device\n"); 171 return -ENOMEM; 172 } 173 174 ts->input = input; 175 input_set_drvdata(input, ts); 176 177 input->name = "raspberrypi-ts"; 178 input->id.bustype = BUS_HOST; 179 180 input_set_abs_params(input, ABS_MT_POSITION_X, 0, 181 RPI_TS_DEFAULT_WIDTH, 0, 0); 182 input_set_abs_params(input, ABS_MT_POSITION_Y, 0, 183 RPI_TS_DEFAULT_HEIGHT, 0, 0); 184 touchscreen_parse_properties(input, true, &ts->prop); 185 186 error = input_mt_init_slots(input, RPI_TS_MAX_SUPPORTED_POINTS, 187 INPUT_MT_DIRECT); 188 if (error) { 189 dev_err(dev, "could not init mt slots, %d\n", error); 190 return error; 191 } 192 193 error = input_setup_polling(input, rpi_ts_poll); 194 if (error) { 195 dev_err(dev, "could not set up polling mode, %d\n", error); 196 return error; 197 } 198 199 input_set_poll_interval(input, RPI_TS_POLL_INTERVAL); 200 201 error = input_register_device(input); 202 if (error) { 203 dev_err(dev, "could not register input device, %d\n", error); 204 return error; 205 } 206 207 return 0; 208 } 209 210 static const struct of_device_id rpi_ts_match[] = { 211 { .compatible = "raspberrypi,firmware-ts", }, 212 {}, 213 }; 214 MODULE_DEVICE_TABLE(of, rpi_ts_match); 215 216 static struct platform_driver rpi_ts_driver = { 217 .driver = { 218 .name = "raspberrypi-ts", 219 .of_match_table = rpi_ts_match, 220 }, 221 .probe = rpi_ts_probe, 222 }; 223 module_platform_driver(rpi_ts_driver); 224 225 MODULE_AUTHOR("Gordon Hollingworth"); 226 MODULE_AUTHOR("Nicolas Saenz Julienne <nsaenzjulienne@suse.de>"); 227 MODULE_DESCRIPTION("Raspberry Pi firmware based touchscreen driver"); 228 MODULE_LICENSE("GPL v2"); 229