--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/bits.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/input.h>
+#include <linux/input/mt.h>
+#include <linux/input/touchscreen.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/property.h>
+#include <linux/regulator/consumer.h>
+
+#define IST3038C_HIB_ACCESS (0x800B << 16)
+#define IST3038C_DIRECT_ACCESS BIT(31)
+#define IST3038C_REG_CHIPID 0x40001000
+#define IST3038C_REG_HIB_BASE 0x30000100
+#define IST3038C_REG_TOUCH_STATUS (IST3038C_REG_HIB_BASE | IST3038C_HIB_ACCESS)
+#define IST3038C_REG_TOUCH_COORD (IST3038C_REG_HIB_BASE | IST3038C_HIB_ACCESS | 0x8)
+#define IST3038C_REG_INTR_MESSAGE (IST3038C_REG_HIB_BASE | IST3038C_HIB_ACCESS | 0x4)
+#define IST3038C_WHOAMI 0x38c
+#define IST3038C_CHIP_ON_DELAY_MS 60
+#define IST3038C_I2C_RETRY_COUNT 3
+#define IST3038C_MAX_FINGER_NUM 10
+#define IST3038C_X_MASK GENMASK(23, 12)
+#define IST3038C_X_SHIFT 12
+#define IST3038C_Y_MASK GENMASK(11, 0)
+#define IST3038C_AREA_MASK GENMASK(27, 24)
+#define IST3038C_AREA_SHIFT 24
+#define IST3038C_FINGER_COUNT_MASK GENMASK(15, 12)
+#define IST3038C_FINGER_COUNT_SHIFT 12
+#define IST3038C_FINGER_STATUS_MASK GENMASK(9, 0)
+
+struct imagis_ts {
+ struct i2c_client *client;
+ struct input_dev *input_dev;
+ struct touchscreen_properties prop;
+ struct regulator_bulk_data supplies[2];
+};
+
+static int imagis_i2c_read_reg(struct imagis_ts *ts,
+ unsigned int reg, u32 *data)
+{
+ __be32 ret_be;
+ __be32 reg_be = cpu_to_be32(reg);
+ struct i2c_msg msg[] = {
+ {
+ .addr = ts->client->addr,
+ .flags = 0,
+ .buf = (unsigned char *)®_be,
+ .len = sizeof(reg_be),
+ }, {
+ .addr = ts->client->addr,
+ .flags = I2C_M_RD,
+ .buf = (unsigned char *)&ret_be,
+ .len = sizeof(ret_be),
+ },
+ };
+ int ret, error;
+ int retry = IST3038C_I2C_RETRY_COUNT;
+
+ /* Retry in case the controller fails to respond */
+ do {
+ ret = i2c_transfer(ts->client->adapter, msg, ARRAY_SIZE(msg));
+ if (ret == ARRAY_SIZE(msg)) {
+ *data = be32_to_cpu(ret_be);
+ return 0;
+ }
+
+ error = ret < 0 ? ret : -EIO;
+ dev_err(&ts->client->dev,
+ "%s - i2c_transfer failed: %d (%d)\n",
+ __func__, error, ret);
+ } while (--retry);
+
+ return error;
+}
+
+static irqreturn_t imagis_interrupt(int irq, void *dev_id)
+{
+ struct imagis_ts *ts = dev_id;
+ u32 intr_message, finger_status;
+ unsigned int finger_count, finger_pressed;
+ int i;
+ int error;
+
+ error = imagis_i2c_read_reg(ts, IST3038C_REG_INTR_MESSAGE,
+ &intr_message);
+ if (error) {
+ dev_err(&ts->client->dev,
+ "failed to read the interrupt message: %d\n", error);
+ goto out;
+ }
+
+ finger_count = (intr_message & IST3038C_FINGER_COUNT_MASK) >>
+ IST3038C_FINGER_COUNT_SHIFT;
+ if (finger_count > IST3038C_MAX_FINGER_NUM) {
+ dev_err(&ts->client->dev,
+ "finger count %d is more than maximum supported\n",
+ finger_count);
+ goto out;
+ }
+
+ finger_pressed = intr_message & IST3038C_FINGER_STATUS_MASK;
+
+ for (i = 0; i < finger_count; i++) {
+ error = imagis_i2c_read_reg(ts,
+ IST3038C_REG_TOUCH_COORD + (i * 4),
+ &finger_status);
+ if (error) {
+ dev_err(&ts->client->dev,
+ "failed to read coordinates for finger %d: %d\n",
+ i, error);
+ goto out;
+ }
+
+ input_mt_slot(ts->input_dev, i);
+ input_mt_report_slot_state(ts->input_dev, MT_TOOL_FINGER,
+ finger_pressed & BIT(i));
+ touchscreen_report_pos(ts->input_dev, &ts->prop,
+ (finger_status & IST3038C_X_MASK) >>
+ IST3038C_X_SHIFT,
+ finger_status & IST3038C_Y_MASK, 1);
+ input_report_abs(ts->input_dev, ABS_MT_TOUCH_MAJOR,
+ (finger_status & IST3038C_AREA_MASK) >>
+ IST3038C_AREA_SHIFT);
+ }
+
+ input_mt_sync_frame(ts->input_dev);
+ input_sync(ts->input_dev);
+
+out:
+ return IRQ_HANDLED;
+}
+
+static void imagis_power_off(void *_ts)
+{
+ struct imagis_ts *ts = _ts;
+
+ regulator_bulk_disable(ARRAY_SIZE(ts->supplies), ts->supplies);
+}
+
+static int imagis_power_on(struct imagis_ts *ts)
+{
+ int error;
+
+ error = regulator_bulk_enable(ARRAY_SIZE(ts->supplies), ts->supplies);
+ if (error)
+ return error;
+
+ msleep(IST3038C_CHIP_ON_DELAY_MS);
+
+ return 0;
+}
+
+static int imagis_start(struct imagis_ts *ts)
+{
+ int error;
+
+ error = imagis_power_on(ts);
+ if (error)
+ return error;
+
+ enable_irq(ts->client->irq);
+
+ return 0;
+}
+
+static int imagis_stop(struct imagis_ts *ts)
+{
+ disable_irq(ts->client->irq);
+
+ imagis_power_off(ts);
+
+ return 0;
+}
+
+static int imagis_input_open(struct input_dev *dev)
+{
+ struct imagis_ts *ts = input_get_drvdata(dev);
+
+ return imagis_start(ts);
+}
+
+static void imagis_input_close(struct input_dev *dev)
+{
+ struct imagis_ts *ts = input_get_drvdata(dev);
+
+ imagis_stop(ts);
+}
+
+static int imagis_init_input_dev(struct imagis_ts *ts)
+{
+ struct input_dev *input_dev;
+ int error;
+
+ input_dev = devm_input_allocate_device(&ts->client->dev);
+ if (!input_dev)
+ return -ENOMEM;
+
+ ts->input_dev = input_dev;
+
+ input_dev->name = "Imagis capacitive touchscreen";
+ input_dev->phys = "input/ts";
+ input_dev->id.bustype = BUS_I2C;
+ input_dev->open = imagis_input_open;
+ input_dev->close = imagis_input_close;
+
+ input_set_drvdata(input_dev, ts);
+
+ 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_TOUCH_MAJOR, 0, 255, 0, 0);
+
+ touchscreen_parse_properties(input_dev, true, &ts->prop);
+ if (!ts->prop.max_x || !ts->prop.max_y) {
+ dev_err(&ts->client->dev,
+ "Touchscreen-size-x and/or touchscreen-size-y not set in dts\n");
+ return -EINVAL;
+ }
+
+ error = input_mt_init_slots(input_dev,
+ IST3038C_MAX_FINGER_NUM,
+ INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
+ if (error) {
+ dev_err(&ts->client->dev,
+ "Failed to initialize MT slots: %d", error);
+ return error;
+ }
+
+ error = input_register_device(input_dev);
+ if (error) {
+ dev_err(&ts->client->dev,
+ "Failed to register input device: %d", error);
+ return error;
+ }
+
+ return 0;
+}
+
+static int imagis_init_regulators(struct imagis_ts *ts)
+{
+ struct i2c_client *client = ts->client;
+
+ ts->supplies[0].supply = "vdd";
+ ts->supplies[1].supply = "vddio";
+ return devm_regulator_bulk_get(&client->dev,
+ ARRAY_SIZE(ts->supplies),
+ ts->supplies);
+}
+
+static int imagis_probe(struct i2c_client *i2c)
+{
+ struct device *dev = &i2c->dev;
+ struct imagis_ts *ts;
+ int chip_id, error;
+
+ ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
+ if (!ts)
+ return -ENOMEM;
+
+ ts->client = i2c;
+
+ error = imagis_init_regulators(ts);
+ if (error) {
+ dev_err(dev, "regulator init error: %d\n", error);
+ return error;
+ }
+
+ error = imagis_power_on(ts);
+ if (error) {
+ dev_err(dev, "failed to enable regulators: %d\n", error);
+ return error;
+ }
+
+ error = devm_add_action_or_reset(dev, imagis_power_off, ts);
+ if (error) {
+ dev_err(dev, "failed to install poweroff action: %d\n", error);
+ return error;
+ }
+
+ error = imagis_i2c_read_reg(ts,
+ IST3038C_REG_CHIPID | IST3038C_DIRECT_ACCESS,
+ &chip_id);
+ if (error) {
+ dev_err(dev, "chip ID read failure: %d\n", error);
+ return error;
+ }
+
+ if (chip_id != IST3038C_WHOAMI) {
+ dev_err(dev, "unknown chip ID: 0x%x\n", chip_id);
+ return -EINVAL;
+ }
+
+ error = devm_request_threaded_irq(dev, i2c->irq,
+ NULL, imagis_interrupt,
+ IRQF_ONESHOT | IRQF_NO_AUTOEN,
+ "imagis-touchscreen", ts);
+ if (error) {
+ dev_err(dev, "IRQ %d allocation failure: %d\n",
+ i2c->irq, error);
+ return error;
+ }
+
+ error = imagis_init_input_dev(ts);
+ if (error)
+ return error;
+
+ return 0;
+}
+
+static int __maybe_unused imagis_suspend(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct imagis_ts *ts = i2c_get_clientdata(client);
+ int retval = 0;
+
+ mutex_lock(&ts->input_dev->mutex);
+
+ if (input_device_enabled(ts->input_dev))
+ retval = imagis_stop(ts);
+
+ mutex_unlock(&ts->input_dev->mutex);
+
+ return retval;
+}
+
+static int __maybe_unused imagis_resume(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct imagis_ts *ts = i2c_get_clientdata(client);
+ int retval = 0;
+
+ mutex_lock(&ts->input_dev->mutex);
+
+ if (input_device_enabled(ts->input_dev))
+ retval = imagis_start(ts);
+
+ mutex_unlock(&ts->input_dev->mutex);
+
+ return retval;
+}
+
+static SIMPLE_DEV_PM_OPS(imagis_pm_ops, imagis_suspend, imagis_resume);
+
+#ifdef CONFIG_OF
+static const struct of_device_id imagis_of_match[] = {
+ { .compatible = "imagis,ist3038c", },
+ { },
+};
+MODULE_DEVICE_TABLE(of, imagis_of_match);
+#endif
+
+static struct i2c_driver imagis_ts_driver = {
+ .driver = {
+ .name = "imagis-touchscreen",
+ .pm = &imagis_pm_ops,
+ .of_match_table = of_match_ptr(imagis_of_match),
+ },
+ .probe_new = imagis_probe,
+};
+
+module_i2c_driver(imagis_ts_driver);
+
+MODULE_DESCRIPTION("Imagis IST3038C Touchscreen Driver");
+MODULE_AUTHOR("Markuss Broks <markuss.broks@gmail.com>");
+MODULE_LICENSE("GPL");
projects / kernel.git / commitdiff