// SPDX-License-Identifier: GPL-2.0 /* * Raspberry Pi firmware based touchscreen driver * * Copyright (C) 2015, 2017 Raspberry Pi * Copyright (C) 2018 Nicolas Saenz Julienne */ #include #include #include #include #include #include #include #include #include #include #include #include #define RPI_TS_DEFAULT_WIDTH 800 #define RPI_TS_DEFAULT_HEIGHT 480 #define RPI_TS_MAX_SUPPORTED_POINTS 10 #define RPI_TS_FTS_TOUCH_DOWN 0 #define RPI_TS_FTS_TOUCH_CONTACT 2 #define RPI_TS_POLL_INTERVAL 17 /* 60fps */ #define RPI_TS_NPOINTS_REG_INVALIDATE 99 struct rpi_ts { struct platform_device *pdev; struct input_dev *input; struct touchscreen_properties prop; void __iomem *fw_regs_va; dma_addr_t fw_regs_phys; int known_ids; }; struct rpi_ts_regs { u8 device_mode; u8 gesture_id; u8 num_points; struct rpi_ts_touch { u8 xh; u8 xl; u8 yh; u8 yl; u8 pressure; /* Not supported */ u8 area; /* Not supported */ } point[RPI_TS_MAX_SUPPORTED_POINTS]; }; static void rpi_ts_poll(struct input_dev *input) { struct rpi_ts *ts = input_get_drvdata(input); struct rpi_ts_regs regs; int modified_ids = 0; long released_ids; int event_type; int touchid; int x, y; int i; memcpy_fromio(®s, ts->fw_regs_va, sizeof(regs)); /* * We poll the memory based register copy of the touchscreen chip using * the number of points register to know whether the copy has been * updated (we write 99 to the memory copy, the GPU will write between * 0 - 10 points) */ iowrite8(RPI_TS_NPOINTS_REG_INVALIDATE, ts->fw_regs_va + offsetof(struct rpi_ts_regs, num_points)); if (regs.num_points == RPI_TS_NPOINTS_REG_INVALIDATE || (regs.num_points == 0 && ts->known_ids == 0)) return; for (i = 0; i < regs.num_points; i++) { x = (((int)regs.point[i].xh & 0xf) << 8) + regs.point[i].xl; y = (((int)regs.point[i].yh & 0xf) << 8) + regs.point[i].yl; touchid = (regs.point[i].yh >> 4) & 0xf; event_type = (regs.point[i].xh >> 6) & 0x03; modified_ids |= BIT(touchid); if (event_type == RPI_TS_FTS_TOUCH_DOWN || event_type == RPI_TS_FTS_TOUCH_CONTACT) { input_mt_slot(input, touchid); input_mt_report_slot_state(input, MT_TOOL_FINGER, 1); touchscreen_report_pos(input, &ts->prop, x, y, true); } } released_ids = ts->known_ids & ~modified_ids; for_each_set_bit(i, &released_ids, RPI_TS_MAX_SUPPORTED_POINTS) { input_mt_slot(input, i); input_mt_report_slot_inactive(input); modified_ids &= ~(BIT(i)); } ts->known_ids = modified_ids; input_mt_sync_frame(input); input_sync(input); } static void rpi_ts_dma_cleanup(void *data) { struct rpi_ts *ts = data; struct device *dev = &ts->pdev->dev; dma_free_coherent(dev, PAGE_SIZE, ts->fw_regs_va, ts->fw_regs_phys); } static int rpi_ts_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct device_node *np = dev->of_node; struct input_dev *input; struct rpi_firmware *fw; struct rpi_ts *ts; u32 touchbuf; int error; struct device_node *fw_node __free(device_node) = of_get_parent(np); if (!fw_node) { dev_err(dev, "Missing firmware node\n"); return -ENOENT; } fw = devm_rpi_firmware_get(&pdev->dev, fw_node); if (!fw) return -EPROBE_DEFER; ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL); if (!ts) return -ENOMEM; ts->pdev = pdev; ts->fw_regs_va = dma_alloc_coherent(dev, PAGE_SIZE, &ts->fw_regs_phys, GFP_KERNEL); if (!ts->fw_regs_va) { dev_err(dev, "failed to dma_alloc_coherent\n"); return -ENOMEM; } error = devm_add_action_or_reset(dev, rpi_ts_dma_cleanup, ts); if (error) { dev_err(dev, "failed to devm_add_action_or_reset, %d\n", error); return error; } touchbuf = (u32)ts->fw_regs_phys; error = rpi_firmware_property(fw, RPI_FIRMWARE_FRAMEBUFFER_SET_TOUCHBUF, &touchbuf, sizeof(touchbuf)); if (error || touchbuf != 0) { dev_warn(dev, "Failed to set touchbuf, %d\n", error); return error; } input = devm_input_allocate_device(dev); if (!input) { dev_err(dev, "Failed to allocate input device\n"); return -ENOMEM; } ts->input = input; input_set_drvdata(input, ts); input->name = "raspberrypi-ts"; input->id.bustype = BUS_HOST; input_set_abs_params(input, ABS_MT_POSITION_X, 0, RPI_TS_DEFAULT_WIDTH, 0, 0); input_set_abs_params(input, ABS_MT_POSITION_Y, 0, RPI_TS_DEFAULT_HEIGHT, 0, 0); touchscreen_parse_properties(input, true, &ts->prop); error = input_mt_init_slots(input, RPI_TS_MAX_SUPPORTED_POINTS, INPUT_MT_DIRECT); if (error) { dev_err(dev, "could not init mt slots, %d\n", error); return error; } error = input_setup_polling(input, rpi_ts_poll); if (error) { dev_err(dev, "could not set up polling mode, %d\n", error); return error; } input_set_poll_interval(input, RPI_TS_POLL_INTERVAL); error = input_register_device(input); if (error) { dev_err(dev, "could not register input device, %d\n", error); return error; } return 0; } static const struct of_device_id rpi_ts_match[] = { { .compatible = "raspberrypi,firmware-ts", }, {}, }; MODULE_DEVICE_TABLE(of, rpi_ts_match); static struct platform_driver rpi_ts_driver = { .driver = { .name = "raspberrypi-ts", .of_match_table = rpi_ts_match, }, .probe = rpi_ts_probe, }; module_platform_driver(rpi_ts_driver); MODULE_AUTHOR("Gordon Hollingworth"); MODULE_AUTHOR("Nicolas Saenz Julienne "); MODULE_DESCRIPTION("Raspberry Pi firmware based touchscreen driver"); MODULE_LICENSE("GPL v2");