--- /dev/null
+/*
+ * Driver for Ntrig/Microsoft Touchscreens over SPI
+ *
+ * Copyright (c) 2016 Red Hat Inc.
+ */
+
+/*
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; version 2 of the License.
+ */
+
+#include <linux/kernel.h>
+
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/input.h>
+#include <linux/input/mt.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/spi/spi.h>
+#include <linux/acpi.h>
+
+#include <asm/unaligned.h>
+
+#define SURFACE3_PACKET_SIZE 264
+
+struct surface3_ts_data {
+ struct spi_device *spi;
+ struct gpio_desc *gpiod_rst[2];
+ struct input_dev *input_dev;
+
+ u8 rd_buf[SURFACE3_PACKET_SIZE] ____cacheline_aligned;
+};
+
+struct surface3_ts_data_finger {
+ u8 status;
+ __le16 tracking_id;
+ __le16 x;
+ __le16 cx;
+ __le16 y;
+ __le16 cy;
+ __le16 width;
+ __le16 height;
+ u32 padding;
+} __packed;
+
+static int surface3_spi_read(struct surface3_ts_data *ts_data)
+{
+ struct spi_device *spi = ts_data->spi;
+
+ memset(ts_data->rd_buf, 0, sizeof(ts_data->rd_buf));
+ return spi_read(spi, ts_data->rd_buf, sizeof(ts_data->rd_buf));
+}
+
+static void surface3_spi_report_touch(struct surface3_ts_data *ts_data,
+ struct surface3_ts_data_finger *finger)
+{
+ int st = finger->status & 0x01;
+ int slot;
+
+ slot = input_mt_get_slot_by_key(ts_data->input_dev,
+ get_unaligned_le16(&finger->tracking_id));
+ if (slot < 0)
+ return;
+
+ input_mt_slot(ts_data->input_dev, slot);
+ input_mt_report_slot_state(ts_data->input_dev, MT_TOOL_FINGER, st);
+ if (st) {
+ input_report_abs(ts_data->input_dev,
+ ABS_MT_POSITION_X,
+ get_unaligned_le16(&finger->x));
+ input_report_abs(ts_data->input_dev,
+ ABS_MT_POSITION_Y,
+ get_unaligned_le16(&finger->y));
+ input_report_abs(ts_data->input_dev,
+ ABS_MT_WIDTH_MAJOR,
+ get_unaligned_le16(&finger->width));
+ input_report_abs(ts_data->input_dev,
+ ABS_MT_WIDTH_MINOR,
+ get_unaligned_le16(&finger->height));
+ }
+}
+
+static void surface3_spi_process(struct surface3_ts_data *ts_data)
+{
+ const char header[] = {0xff, 0xff, 0xff, 0xff, 0xa5, 0x5a, 0xe7, 0x7e,
+ 0x01, 0xd2, 0x00, 0x80, 0x01, 0x03, 0x03};
+ u8 *data = ts_data->rd_buf;
+ u16 timestamp;
+ unsigned int i;
+
+ if (memcmp(header, data, sizeof(header)))
+ dev_err(&ts_data->spi->dev,
+ "%s header error: %*ph, ignoring...\n",
+ __func__, (int)sizeof(header), data);
+
+ timestamp = get_unaligned_le16(&data[15]);
+
+ for (i = 0; i < 13; i++) {
+ struct surface3_ts_data_finger *finger;
+
+ finger = (struct surface3_ts_data_finger *)&data[17 +
+ i * sizeof(struct surface3_ts_data_finger)];
+
+ /*
+ * When bit 5 of status is 1, it marks the end of the report:
+ * - touch present: 0xe7
+ * - touch released: 0xe4
+ * - nothing valuable: 0xff
+ */
+ if (finger->status & 0x10)
+ break;
+
+ surface3_spi_report_touch(ts_data, finger);
+ }
+
+ input_mt_sync_frame(ts_data->input_dev);
+ input_sync(ts_data->input_dev);
+}
+
+static irqreturn_t surface3_spi_irq_handler(int irq, void *dev_id)
+{
+ struct surface3_ts_data *data = dev_id;
+
+ if (surface3_spi_read(data))
+ return IRQ_HANDLED;
+
+ dev_dbg(&data->spi->dev, "%s received -> %*ph\n",
+ __func__, SURFACE3_PACKET_SIZE, data->rd_buf);
+ surface3_spi_process(data);
+
+ return IRQ_HANDLED;
+}
+
+static void surface3_spi_power(struct surface3_ts_data *data, bool on)
+{
+ gpiod_set_value(data->gpiod_rst[0], on);
+ gpiod_set_value(data->gpiod_rst[1], on);
+ /* let the device settle a little */
+ msleep(20);
+}
+
+/**
+ * surface3_spi_get_gpio_config - Get GPIO config from ACPI/DT
+ *
+ * @ts: surface3_spi_ts_data pointer
+ */
+static int surface3_spi_get_gpio_config(struct surface3_ts_data *data)
+{
+ int error;
+ struct device *dev;
+ struct gpio_desc *gpiod;
+ int i;
+
+ dev = &data->spi->dev;
+
+ /* Get the reset lines GPIO pin number */
+ for (i = 0; i < 2; i++) {
+ gpiod = devm_gpiod_get_index(dev, NULL, i, GPIOD_OUT_LOW);
+ if (IS_ERR(gpiod)) {
+ error = PTR_ERR(gpiod);
+ if (error != -EPROBE_DEFER)
+ dev_err(dev,
+ "Failed to get power GPIO %d: %d\n",
+ i,
+ error);
+ return error;
+ }
+
+ data->gpiod_rst[i] = gpiod;
+ }
+
+ return 0;
+}
+
+static int surface3_spi_create_input(struct surface3_ts_data *data)
+{
+ struct input_dev *input;
+ int error;
+
+ input = devm_input_allocate_device(&data->spi->dev);
+ if (!input)
+ return -ENOMEM;
+
+ data->input_dev = input;
+
+ input_set_abs_params(input, ABS_MT_POSITION_X, 0, 9600, 0, 0);
+ input_abs_set_res(input, ABS_MT_POSITION_X, 40);
+ input_set_abs_params(input, ABS_MT_POSITION_Y, 0, 7200, 0, 0);
+ input_abs_set_res(input, ABS_MT_POSITION_Y, 48);
+ input_set_abs_params(input, ABS_MT_WIDTH_MAJOR, 0, 1024, 0, 0);
+ input_set_abs_params(input, ABS_MT_WIDTH_MINOR, 0, 1024, 0, 0);
+ input_mt_init_slots(input, 10, INPUT_MT_DIRECT);
+
+ input->name = "Surface3 SPI Capacitive TouchScreen";
+ input->phys = "input/ts";
+ input->id.bustype = BUS_SPI;
+ input->id.vendor = 0x045e; /* Microsoft */
+ input->id.product = 0x0000;
+ input->id.version = 0x0000;
+
+ error = input_register_device(input);
+ if (error) {
+ dev_err(&data->spi->dev,
+ "Failed to register input device: %d", error);
+ return error;
+ }
+
+ return 0;
+}
+
+static int surface3_spi_probe(struct spi_device *spi)
+{
+ struct surface3_ts_data *data;
+ int error;
+
+ /* Set up SPI*/
+ spi->bits_per_word = 8;
+ spi->mode = SPI_MODE_0;
+ error = spi_setup(spi);
+ if (error)
+ return error;
+
+ data = devm_kzalloc(&spi->dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->spi = spi;
+ spi_set_drvdata(spi, data);
+
+ error = surface3_spi_get_gpio_config(data);
+ if (error)
+ return error;
+
+ surface3_spi_power(data, true);
+ surface3_spi_power(data, false);
+ surface3_spi_power(data, true);
+
+ error = surface3_spi_create_input(data);
+ if (error)
+ return error;
+
+ error = devm_request_threaded_irq(&spi->dev, spi->irq,
+ NULL, surface3_spi_irq_handler,
+ IRQF_ONESHOT,
+ "Surface3-irq", data);
+ if (error)
+ return error;
+
+ return 0;
+}
+
+static int __maybe_unused surface3_spi_suspend(struct device *dev)
+{
+ struct spi_device *spi = to_spi_device(dev);
+ struct surface3_ts_data *data = spi_get_drvdata(spi);
+
+ disable_irq(data->spi->irq);
+
+ surface3_spi_power(data, false);
+
+ return 0;
+}
+
+static int __maybe_unused surface3_spi_resume(struct device *dev)
+{
+ struct spi_device *spi = to_spi_device(dev);
+ struct surface3_ts_data *data = spi_get_drvdata(spi);
+
+ surface3_spi_power(data, true);
+
+ enable_irq(data->spi->irq);
+
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(surface3_spi_pm_ops,
+ surface3_spi_suspend,
+ surface3_spi_resume);
+
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id surface3_spi_acpi_match[] = {
+ { "MSHW0037", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(acpi, surface3_spi_acpi_match);
+#endif
+
+static struct spi_driver surface3_spi_driver = {
+ .driver = {
+ .name = "Surface3-spi",
+ .acpi_match_table = ACPI_PTR(surface3_spi_acpi_match),
+ .pm = &surface3_spi_pm_ops,
+ },
+ .probe = surface3_spi_probe,
+};
+
+module_spi_driver(surface3_spi_driver);
+
+MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
+MODULE_DESCRIPTION("Surface 3 SPI touchscreen driver");
+MODULE_LICENSE("GPL v2");
projects / karo-tx-linux.git / commitdiff