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Diffstat (limited to '')
| -rw-r--r-- | drivers/input/touchscreen/raspberrypi-ts.c | 228 |
1 files changed, 228 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/raspberrypi-ts.c b/drivers/input/touchscreen/raspberrypi-ts.c new file mode 100644 index 000000000..45c575df9 --- /dev/null +++ b/drivers/input/touchscreen/raspberrypi-ts.c @@ -0,0 +1,228 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Raspberry Pi firmware based touchscreen driver + * + * Copyright (C) 2015, 2017 Raspberry Pi + * Copyright (C) 2018 Nicolas Saenz Julienne <nsaenzjulienne@suse.de> + */ + +#include <linux/io.h> +#include <linux/of.h> +#include <linux/slab.h> +#include <linux/device.h> +#include <linux/module.h> +#include <linux/bitops.h> +#include <linux/dma-mapping.h> +#include <linux/platform_device.h> +#include <linux/input.h> +#include <linux/input/mt.h> +#include <linux/input/touchscreen.h> +#include <soc/bcm2835/raspberrypi-firmware.h> + +#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 device_node *fw_node; + struct rpi_firmware *fw; + struct rpi_ts *ts; + u32 touchbuf; + int error; + + fw_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); + of_node_put(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 <nsaenzjulienne@suse.de>"); +MODULE_DESCRIPTION("Raspberry Pi firmware based touchscreen driver"); +MODULE_LICENSE("GPL v2"); |