Add support for the msg2638 touchscreen IC from MStar.
This driver reuses zinitix.c structure, while the checksum and irq handler
functions are based on out-of-tree driver for Alcatel Idol 3 (4.7").
Signed-off-by: Vincent Knecht <vincent.knecht@xxxxxxxxxx>
---
Changed in v4:
- rename from msg26xx to msg2638, following compatible string change
- rename mstar_* functions to msg2638_* for consistency
- add RESET_DELAY define and use it in msg2638_power_on()
- change a few dev_err() calls to be on one line only
- add missing \n in a few dev_err() strings
Changed in v3:
- no change
Changed in v2:
- don't use bitfields in packet struct, to prevent endian-ness related problems (Dmitry)
- fix reset gpiod calls order in mstar_power_on() (Dmitry)
---
drivers/input/touchscreen/Kconfig | 12 +
drivers/input/touchscreen/Makefile | 1 +
drivers/input/touchscreen/msg2638.c | 362 ++++++++++++++++++++++++++++
3 files changed, 375 insertions(+)
create mode 100644 drivers/input/touchscreen/msg2638.c
diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index f012fe746df0..fefbe1c1bb10 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -1334,4 +1334,16 @@ config TOUCHSCREEN_ZINITIX
To compile this driver as a module, choose M here: the
module will be called zinitix.
+config TOUCHSCREEN_MSG2638
+ tristate "MStar msg2638 touchscreen support"
+ depends on I2C
+ depends on GPIOLIB || COMPILE_TEST
+ help
+ Say Y here if you have an I2C touchscreen using MStar msg2638.
+
+ If unsure, say N.
+
+ To compile this driver as a module, choose M here: the
+ module will be called msg2638.
+
endif
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 6233541e9173..83e516cb3d33 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -112,3 +112,4 @@ obj-$(CONFIG_TOUCHSCREEN_ROHM_BU21023) += rohm_bu21023.o
obj-$(CONFIG_TOUCHSCREEN_RASPBERRYPI_FW) += raspberrypi-ts.o
obj-$(CONFIG_TOUCHSCREEN_IQS5XX) += iqs5xx.o
obj-$(CONFIG_TOUCHSCREEN_ZINITIX) += zinitix.o
+obj-$(CONFIG_TOUCHSCREEN_MSG2638) += msg2638.o
diff --git a/drivers/input/touchscreen/msg2638.c b/drivers/input/touchscreen/msg2638.c
new file mode 100644
index 000000000000..e00cff923fe2
--- /dev/null
+++ b/drivers/input/touchscreen/msg2638.c
@@ -0,0 +1,362 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Driver for MStar msg2638 touchscreens
+ *
+ * Copyright (c) 2021 Vincent Knecht <vincent.knecht@xxxxxxxxxx>
+ *
+ * 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@xxxxxxxxx>
+ */
+
+#include <linux/delay.h>
+#include <linux/gpio.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/irq.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+
+#define MODE_DATA_RAW 0x5A
+
+#define TPD_WIDTH 2048
+#define TPD_HEIGHT 2048
+
+#define MAX_SUPPORTED_FINGER_NUM 5
+
+#define CHIP_ON_DELAY 15 // ms
+#define FIRMWARE_ON_DELAY 50 // ms
+#define RESET_DELAY 10 // ms
+
+struct point_coord {
+ u16 x;
+ u16 y;
+};
+
+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 int msg2638_init_regulators(struct msg2638_ts_data *msg2638)
+{
+ struct i2c_client *client = msg2638->client;
+ int error;
+
+ msg2638->supplies[0].supply = "vdd";
+ msg2638->supplies[1].supply = "vddio";
+ error = devm_regulator_bulk_get(&client->dev,
+ ARRAY_SIZE(msg2638->supplies),
+ msg2638->supplies);
+ if (error < 0) {
+ dev_err(&client->dev, "Failed to get regulators: %d\n", error);
+ return error;
+ }
+
+ return 0;
+}
+
+static void msg2638_power_on(struct msg2638_ts_data *msg2638)
+{
+ gpiod_set_value(msg2638->reset_gpiod, 1);
+ mdelay(RESET_DELAY);
+ gpiod_set_value(msg2638->reset_gpiod, 0);
+ mdelay(FIRMWARE_ON_DELAY);
+
+ enable_irq(msg2638->client->irq);
+}
+
+static void msg2638_report_finger(struct msg2638_ts_data *msg2638, int slot,
+ const struct point_coord *pc)
+{
+ input_mt_slot(msg2638->input_dev, slot);
+ input_mt_report_slot_state(msg2638->input_dev, MT_TOOL_FINGER, true);
+ touchscreen_report_pos(msg2638->input_dev, &msg2638->prop, pc->x, pc->y, true);
+ input_report_abs(msg2638->input_dev, ABS_MT_TOUCH_MAJOR, 1);
+}
+
+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 touch_event touch_event;
+ struct point_coord coord;
+ struct i2c_msg msg[1];
+ struct packet *p;
+ u32 len;
+ int ret;
+ int i;
+
+ len = sizeof(struct touch_event);
+ memset(&touch_event, 0, len);
+
+ msg[0].addr = client->addr;
+ msg[0].flags = I2C_M_RD;
+ msg[0].len = len;
+ msg[0].buf = (u8 *)&touch_event;
+
+ ret = i2c_transfer(client->adapter, msg, 1);
+ if (ret != 1) {
+ dev_err(&client->dev, "Failed I2C transfer in irq handler!\n");
+ 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;
+
+ coord.x = (((p->xy_hi & 0xF0) << 4) | p->x_low) * msg2638->prop.max_x / TPD_WIDTH;
+ coord.y = (((p->xy_hi & 0x0F) << 8) | p->y_low) * msg2638->prop.max_y / TPD_HEIGHT;
+ msg2638_report_finger(msg2638, i, &coord);
+ }
+
+ input_mt_sync_frame(msg2638->input_dev);
+ input_sync(msg2638->input_dev);
+
+out:
+ return IRQ_HANDLED;
+}
+
+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);
+
+ msg2638_power_on(msg2638);
+
+ 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 input_dev *input_dev;
+ int error;
+
+ input_dev = devm_input_allocate_device(&msg2638->client->dev);
+ if (!input_dev) {
+ dev_err(&msg2638->client->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);
+ input_set_abs_params(input_dev, ABS_MT_WIDTH_MAJOR, 0, 15, 0, 0);
+ input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0);
+
+ touchscreen_parse_properties(input_dev, true, &msg2638->prop);
+ if (!msg2638->prop.max_x || !msg2638->prop.max_y) {
+ dev_err(&msg2638->client->dev,
+ "touchscreen-size-x and/or touchscreen-size-y not set in dts\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(&msg2638->client->dev, "Failed to initialize MT slots: %d\n", error);
+ return error;
+ }
+
+ error = input_register_device(input_dev);
+ if (error) {
+ dev_err(&msg2638->client->dev, "Failed to register input device: %d\n", error);
+ return error;
+ }
+
+ return 0;
+}
+
+static int msg2638_ts_probe(struct i2c_client *client)
+{
+ struct msg2638_ts_data *msg2638;
+ int error;
+
+ if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+ dev_err(&client->dev, "Failed to assert adapter's support for plain I2C.\n");
+ return -ENXIO;
+ }
+
+ msg2638 = devm_kzalloc(&client->dev, sizeof(*msg2638), GFP_KERNEL);
+ if (!msg2638)
+ return -ENOMEM;
+
+ msg2638->client = client;
+ i2c_set_clientdata(client, msg2638);
+
+ error = msg2638_init_regulators(msg2638);
+ if (error) {
+ dev_err(&client->dev, "Failed to initialize regulators: %d\n", error);
+ return error;
+ }
+
+ msg2638->reset_gpiod = devm_gpiod_get(&client->dev, "reset", GPIOD_OUT_LOW);
+ if (IS_ERR(msg2638->reset_gpiod)) {
+ error = PTR_ERR(msg2638->reset_gpiod);
+ dev_err(&client->dev, "Failed to request reset GPIO: %d\n", error);
+ return error;
+ }
+
+ error = msg2638_init_input_dev(msg2638);
+ if (error) {
+ dev_err(&client->dev, "Failed to initialize input device: %d\n", error);
+ return error;
+ }
+
+ irq_set_status_flags(client->irq, IRQ_NOAUTOEN);
+ error = devm_request_threaded_irq(&client->dev, client->irq,
+ NULL, msg2638_ts_irq_handler,
+ IRQF_ONESHOT, client->name, msg2638);
+ if (error) {
+ dev_err(&client->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);
+
+#ifdef CONFIG_OF
+static const struct of_device_id msg2638_of_match[] = {
+ { .compatible = "mstar,msg2638" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, msg2638_of_match);
+#endif
+
+static struct i2c_driver msg2638_ts_driver = {
+ .probe_new = msg2638_ts_probe,
+ .driver = {
+ .name = "MStar-TS",
+ .pm = &msg2638_pm_ops,
+ .of_match_table = of_match_ptr(msg2638_of_match),
+ },
+};
+module_i2c_driver(msg2638_ts_driver);
+
+MODULE_AUTHOR("Vincent Knecht <vincent.knecht@xxxxxxxxxx>");
+MODULE_DESCRIPTION("MStar MSG2638 touchscreen driver");
+MODULE_LICENSE("GPL v2");
--
2.29.2
