--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Driver for MStar msg2638 touchscreens
+ *
+ * Copyright (c) 2021 Vincent Knecht <vincent.knecht@mailoo.org>
+ *
+ * Checksum and IRQ handler based on mstar_drv_common.c and
+ * mstar_drv_mutual_fw_control.c
+ * Copyright (c) 2006-2012 MStar Semiconductor, Inc.
+ *
+ * Driver structure based on zinitix.c by Michael Srba <Michael.Srba@seznam.cz>
+ */
+
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/input.h>
+#include <linux/input/mt.h>
+#include <linux/input/touchscreen.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+
+#define MODE_DATA_RAW 0x5A
+
+#define MAX_SUPPORTED_FINGER_NUM 5
+
+#define CHIP_ON_DELAY_MS 15
+#define FIRMWARE_ON_DELAY_MS 50
+#define RESET_DELAY_MIN_US 10000
+#define RESET_DELAY_MAX_US 11000
+
+struct packet {
+ u8 xy_hi; /* higher bits of x and y coordinates */
+ u8 x_low;
+ u8 y_low;
+ u8 pressure;
+};
+
+struct touch_event {
+ u8 mode;
+ struct packet pkt[MAX_SUPPORTED_FINGER_NUM];
+ u8 proximity;
+ u8 checksum;
+};
+
+struct msg2638_ts_data {
+ struct i2c_client *client;
+ struct input_dev *input_dev;
+ struct touchscreen_properties prop;
+ struct regulator_bulk_data supplies[2];
+ struct gpio_desc *reset_gpiod;
+};
+
+static u8 msg2638_checksum(u8 *data, u32 length)
+{
+ s32 sum = 0;
+ u32 i;
+
+ for (i = 0; i < length; i++)
+ sum += data[i];
+
+ return (u8)((-sum) & 0xFF);
+}
+
+static irqreturn_t msg2638_ts_irq_handler(int irq, void *msg2638_handler)
+{
+ struct msg2638_ts_data *msg2638 = msg2638_handler;
+ struct i2c_client *client = msg2638->client;
+ struct input_dev *input = msg2638->input_dev;
+ struct touch_event touch_event;
+ u32 len = sizeof(touch_event);
+ struct i2c_msg msg[] = {
+ {
+ .addr = client->addr,
+ .flags = I2C_M_RD,
+ .len = sizeof(touch_event),
+ .buf = (u8 *)&touch_event,
+ },
+ };
+ struct packet *p;
+ u16 x, y;
+ int ret;
+ int i;
+
+ ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
+ if (ret != ARRAY_SIZE(msg)) {
+ dev_err(&client->dev,
+ "Failed I2C transfer in irq handler: %d\n",
+ ret < 0 ? ret : -EIO);
+ goto out;
+ }
+
+ if (touch_event.mode != MODE_DATA_RAW)
+ goto out;
+
+ if (msg2638_checksum((u8 *)&touch_event, len - 1) !=
+ touch_event.checksum) {
+ dev_err(&client->dev, "Failed checksum!\n");
+ goto out;
+ }
+
+ for (i = 0; i < MAX_SUPPORTED_FINGER_NUM; i++) {
+ p = &touch_event.pkt[i];
+
+ /* Ignore non-pressed finger data */
+ if (p->xy_hi == 0xFF && p->x_low == 0xFF && p->y_low == 0xFF)
+ continue;
+
+ x = (((p->xy_hi & 0xF0) << 4) | p->x_low);
+ y = (((p->xy_hi & 0x0F) << 8) | p->y_low);
+
+ input_mt_slot(input, i);
+ input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
+ touchscreen_report_pos(input, &msg2638->prop, x, y, true);
+ }
+
+ input_mt_sync_frame(msg2638->input_dev);
+ input_sync(msg2638->input_dev);
+
+out:
+ return IRQ_HANDLED;
+}
+
+static void msg2638_reset(struct msg2638_ts_data *msg2638)
+{
+ gpiod_set_value_cansleep(msg2638->reset_gpiod, 1);
+ usleep_range(RESET_DELAY_MIN_US, RESET_DELAY_MAX_US);
+ gpiod_set_value_cansleep(msg2638->reset_gpiod, 0);
+ msleep(FIRMWARE_ON_DELAY_MS);
+}
+
+static int msg2638_start(struct msg2638_ts_data *msg2638)
+{
+ int error;
+
+ error = regulator_bulk_enable(ARRAY_SIZE(msg2638->supplies),
+ msg2638->supplies);
+ if (error) {
+ dev_err(&msg2638->client->dev,
+ "Failed to enable regulators: %d\n", error);
+ return error;
+ }
+
+ msleep(CHIP_ON_DELAY_MS);
+
+ msg2638_reset(msg2638);
+
+ enable_irq(msg2638->client->irq);
+
+ return 0;
+}
+
+static int msg2638_stop(struct msg2638_ts_data *msg2638)
+{
+ int error;
+
+ disable_irq(msg2638->client->irq);
+
+ error = regulator_bulk_disable(ARRAY_SIZE(msg2638->supplies),
+ msg2638->supplies);
+ if (error) {
+ dev_err(&msg2638->client->dev,
+ "Failed to disable regulators: %d\n", error);
+ return error;
+ }
+
+ return 0;
+}
+
+static int msg2638_input_open(struct input_dev *dev)
+{
+ struct msg2638_ts_data *msg2638 = input_get_drvdata(dev);
+
+ return msg2638_start(msg2638);
+}
+
+static void msg2638_input_close(struct input_dev *dev)
+{
+ struct msg2638_ts_data *msg2638 = input_get_drvdata(dev);
+
+ msg2638_stop(msg2638);
+}
+
+static int msg2638_init_input_dev(struct msg2638_ts_data *msg2638)
+{
+ struct device *dev = &msg2638->client->dev;
+ struct input_dev *input_dev;
+ int error;
+
+ input_dev = devm_input_allocate_device(dev);
+ if (!input_dev) {
+ dev_err(dev, "Failed to allocate input device.\n");
+ return -ENOMEM;
+ }
+
+ input_set_drvdata(input_dev, msg2638);
+ msg2638->input_dev = input_dev;
+
+ input_dev->name = "MStar TouchScreen";
+ input_dev->phys = "input/ts";
+ input_dev->id.bustype = BUS_I2C;
+ input_dev->open = msg2638_input_open;
+ input_dev->close = msg2638_input_close;
+
+ input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_X);
+ input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_Y);
+
+ touchscreen_parse_properties(input_dev, true, &msg2638->prop);
+ if (!msg2638->prop.max_x || !msg2638->prop.max_y) {
+ dev_err(dev, "touchscreen-size-x and/or touchscreen-size-y not set in properties\n");
+ return -EINVAL;
+ }
+
+ error = input_mt_init_slots(input_dev, MAX_SUPPORTED_FINGER_NUM,
+ INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
+ if (error) {
+ dev_err(dev, "Failed to initialize MT slots: %d\n", error);
+ return error;
+ }
+
+ error = input_register_device(input_dev);
+ if (error) {
+ dev_err(dev, "Failed to register input device: %d\n", error);
+ return error;
+ }
+
+ return 0;
+}
+
+static int msg2638_ts_probe(struct i2c_client *client)
+{
+ struct device *dev = &client->dev;
+ struct msg2638_ts_data *msg2638;
+ int error;
+
+ if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+ dev_err(dev, "Failed to assert adapter's support for plain I2C.\n");
+ return -ENXIO;
+ }
+
+ msg2638 = devm_kzalloc(dev, sizeof(*msg2638), GFP_KERNEL);
+ if (!msg2638)
+ return -ENOMEM;
+
+ msg2638->client = client;
+ i2c_set_clientdata(client, msg2638);
+
+ msg2638->supplies[0].supply = "vdd";
+ msg2638->supplies[1].supply = "vddio";
+ error = devm_regulator_bulk_get(dev, ARRAY_SIZE(msg2638->supplies),
+ msg2638->supplies);
+ if (error) {
+ dev_err(dev, "Failed to get regulators: %d\n", error);
+ return error;
+ }
+
+ msg2638->reset_gpiod = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
+ if (IS_ERR(msg2638->reset_gpiod)) {
+ error = PTR_ERR(msg2638->reset_gpiod);
+ dev_err(dev, "Failed to request reset GPIO: %d\n", error);
+ return error;
+ }
+
+ error = msg2638_init_input_dev(msg2638);
+ if (error) {
+ dev_err(dev, "Failed to initialize input device: %d\n", error);
+ return error;
+ }
+
+ error = devm_request_threaded_irq(dev, client->irq,
+ NULL, msg2638_ts_irq_handler,
+ IRQF_ONESHOT | IRQF_NO_AUTOEN,
+ client->name, msg2638);
+ if (error) {
+ dev_err(dev, "Failed to request IRQ: %d\n", error);
+ return error;
+ }
+
+ return 0;
+}
+
+static int __maybe_unused msg2638_suspend(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct msg2638_ts_data *msg2638 = i2c_get_clientdata(client);
+
+ mutex_lock(&msg2638->input_dev->mutex);
+
+ if (input_device_enabled(msg2638->input_dev))
+ msg2638_stop(msg2638);
+
+ mutex_unlock(&msg2638->input_dev->mutex);
+
+ return 0;
+}
+
+static int __maybe_unused msg2638_resume(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct msg2638_ts_data *msg2638 = i2c_get_clientdata(client);
+ int ret = 0;
+
+ mutex_lock(&msg2638->input_dev->mutex);
+
+ if (input_device_enabled(msg2638->input_dev))
+ ret = msg2638_start(msg2638);
+
+ mutex_unlock(&msg2638->input_dev->mutex);
+
+ return ret;
+}
+
+static SIMPLE_DEV_PM_OPS(msg2638_pm_ops, msg2638_suspend, msg2638_resume);
+
+static const struct of_device_id msg2638_of_match[] = {
+ { .compatible = "mstar,msg2638" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, msg2638_of_match);
+
+static struct i2c_driver msg2638_ts_driver = {
+ .probe_new = msg2638_ts_probe,
+ .driver = {
+ .name = "MStar-TS",
+ .pm = &msg2638_pm_ops,
+ .of_match_table = msg2638_of_match,
+ },
+};
+module_i2c_driver(msg2638_ts_driver);
+
+MODULE_AUTHOR("Vincent Knecht <vincent.knecht@mailoo.org>");
+MODULE_DESCRIPTION("MStar MSG2638 touchscreen driver");
+MODULE_LICENSE("GPL v2");
git.samba.org / sfrench / cifs-2.6.git / blobdiff