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path: root/drivers/input/touchscreen/hynitron_cstxxx.c
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Diffstat (limited to 'drivers/input/touchscreen/hynitron_cstxxx.c')
-rw-r--r--drivers/input/touchscreen/hynitron_cstxxx.c498
1 files changed, 498 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/hynitron_cstxxx.c b/drivers/input/touchscreen/hynitron_cstxxx.c
new file mode 100644
index 0000000000..05946fee4f
--- /dev/null
+++ b/drivers/input/touchscreen/hynitron_cstxxx.c
@@ -0,0 +1,498 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Driver for Hynitron cstxxx Touchscreen
+ *
+ * Copyright (c) 2022 Chris Morgan <macromorgan@hotmail.com>
+ *
+ * This code is based on hynitron_core.c authored by Hynitron.
+ * Note that no datasheet was available, so much of these registers
+ * are undocumented. This is essentially a cleaned-up version of the
+ * vendor driver with support removed for hardware I cannot test and
+ * device-specific functions replated with generic functions wherever
+ * possible.
+ */
+
+#include <linux/delay.h>
+#include <linux/err.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/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/property.h>
+#include <asm/unaligned.h>
+
+/* Per chip data */
+struct hynitron_ts_chip_data {
+ unsigned int max_touch_num;
+ u32 ic_chkcode;
+ int (*firmware_info)(struct i2c_client *client);
+ int (*bootloader_enter)(struct i2c_client *client);
+ int (*init_input)(struct i2c_client *client);
+ void (*report_touch)(struct i2c_client *client);
+};
+
+/* Data generic to all (supported and non-supported) controllers. */
+struct hynitron_ts_data {
+ const struct hynitron_ts_chip_data *chip;
+ struct i2c_client *client;
+ struct input_dev *input_dev;
+ struct touchscreen_properties prop;
+ struct gpio_desc *reset_gpio;
+};
+
+/*
+ * Since I have no datasheet, these values are guessed and/or assumed
+ * based on observation and testing.
+ */
+#define CST3XX_FIRMWARE_INFO_START_CMD 0x01d1
+#define CST3XX_FIRMWARE_INFO_END_CMD 0x09d1
+#define CST3XX_FIRMWARE_CHK_CODE_REG 0xfcd1
+#define CST3XX_FIRMWARE_VERSION_REG 0x08d2
+#define CST3XX_FIRMWARE_VER_INVALID_VAL 0xa5a5a5a5
+
+#define CST3XX_BOOTLDR_PROG_CMD 0xaa01a0
+#define CST3XX_BOOTLDR_PROG_CHK_REG 0x02a0
+#define CST3XX_BOOTLDR_CHK_VAL 0xac
+
+#define CST3XX_TOUCH_DATA_PART_REG 0x00d0
+#define CST3XX_TOUCH_DATA_FULL_REG 0x07d0
+#define CST3XX_TOUCH_DATA_CHK_VAL 0xab
+#define CST3XX_TOUCH_DATA_TOUCH_VAL 0x03
+#define CST3XX_TOUCH_DATA_STOP_CMD 0xab00d0
+#define CST3XX_TOUCH_COUNT_MASK GENMASK(6, 0)
+
+
+/*
+ * Hard coded reset delay value of 20ms not IC dependent in
+ * vendor driver.
+ */
+static void hyn_reset_proc(struct i2c_client *client, int delay)
+{
+ struct hynitron_ts_data *ts_data = i2c_get_clientdata(client);
+
+ gpiod_set_value_cansleep(ts_data->reset_gpio, 1);
+ msleep(20);
+ gpiod_set_value_cansleep(ts_data->reset_gpio, 0);
+ if (delay)
+ fsleep(delay * 1000);
+}
+
+static irqreturn_t hyn_interrupt_handler(int irq, void *dev_id)
+{
+ struct i2c_client *client = dev_id;
+ struct hynitron_ts_data *ts_data = i2c_get_clientdata(client);
+
+ ts_data->chip->report_touch(client);
+
+ return IRQ_HANDLED;
+}
+
+/*
+ * The vendor driver would retry twice before failing to read or write
+ * to the i2c device.
+ */
+
+static int cst3xx_i2c_write(struct i2c_client *client,
+ unsigned char *buf, int len)
+{
+ int ret;
+ int retries = 0;
+
+ while (retries < 2) {
+ ret = i2c_master_send(client, buf, len);
+ if (ret == len)
+ return 0;
+ if (ret <= 0)
+ retries++;
+ else
+ break;
+ }
+
+ return ret < 0 ? ret : -EIO;
+}
+
+static int cst3xx_i2c_read_register(struct i2c_client *client, u16 reg,
+ u8 *val, u16 len)
+{
+ __le16 buf = cpu_to_le16(reg);
+ struct i2c_msg msgs[] = {
+ {
+ .addr = client->addr,
+ .flags = 0,
+ .len = 2,
+ .buf = (u8 *)&buf,
+ },
+ {
+ .addr = client->addr,
+ .flags = I2C_M_RD,
+ .len = len,
+ .buf = val,
+ }
+ };
+ int err;
+ int ret;
+
+ ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
+ if (ret == ARRAY_SIZE(msgs))
+ return 0;
+
+ err = ret < 0 ? ret : -EIO;
+ dev_err(&client->dev, "Error reading %d bytes from 0x%04x: %d (%d)\n",
+ len, reg, err, ret);
+
+ return err;
+}
+
+static int cst3xx_firmware_info(struct i2c_client *client)
+{
+ struct hynitron_ts_data *ts_data = i2c_get_clientdata(client);
+ int err;
+ u32 tmp;
+ unsigned char buf[4];
+
+ /*
+ * Tests suggest this command needed to read firmware regs.
+ */
+ put_unaligned_le16(CST3XX_FIRMWARE_INFO_START_CMD, buf);
+ err = cst3xx_i2c_write(client, buf, 2);
+ if (err)
+ return err;
+
+ usleep_range(10000, 11000);
+
+ /*
+ * Read register for check-code to determine if device detected
+ * correctly.
+ */
+ err = cst3xx_i2c_read_register(client, CST3XX_FIRMWARE_CHK_CODE_REG,
+ buf, 4);
+ if (err)
+ return err;
+
+ tmp = get_unaligned_le32(buf);
+ if ((tmp & 0xffff0000) != ts_data->chip->ic_chkcode) {
+ dev_err(&client->dev, "%s ic mismatch, chkcode is %u\n",
+ __func__, tmp);
+ return -ENODEV;
+ }
+
+ usleep_range(10000, 11000);
+
+ /* Read firmware version and test if firmware missing. */
+ err = cst3xx_i2c_read_register(client, CST3XX_FIRMWARE_VERSION_REG,
+ buf, 4);
+ if (err)
+ return err;
+
+ tmp = get_unaligned_le32(buf);
+ if (tmp == CST3XX_FIRMWARE_VER_INVALID_VAL) {
+ dev_err(&client->dev, "Device firmware missing\n");
+ return -ENODEV;
+ }
+
+ /*
+ * Tests suggest cmd required to exit reading firmware regs.
+ */
+ put_unaligned_le16(CST3XX_FIRMWARE_INFO_END_CMD, buf);
+ err = cst3xx_i2c_write(client, buf, 2);
+ if (err)
+ return err;
+
+ usleep_range(5000, 6000);
+
+ return 0;
+}
+
+static int cst3xx_bootloader_enter(struct i2c_client *client)
+{
+ int err;
+ u8 retry;
+ u32 tmp = 0;
+ unsigned char buf[3];
+
+ for (retry = 0; retry < 5; retry++) {
+ hyn_reset_proc(client, (7 + retry));
+ /* set cmd to enter program mode */
+ put_unaligned_le24(CST3XX_BOOTLDR_PROG_CMD, buf);
+ err = cst3xx_i2c_write(client, buf, 3);
+ if (err)
+ continue;
+
+ usleep_range(2000, 2500);
+
+ /* check whether in program mode */
+ err = cst3xx_i2c_read_register(client,
+ CST3XX_BOOTLDR_PROG_CHK_REG,
+ buf, 1);
+ if (err)
+ continue;
+
+ tmp = get_unaligned(buf);
+ if (tmp == CST3XX_BOOTLDR_CHK_VAL)
+ break;
+ }
+
+ if (tmp != CST3XX_BOOTLDR_CHK_VAL) {
+ dev_err(&client->dev, "%s unable to enter bootloader mode\n",
+ __func__);
+ return -ENODEV;
+ }
+
+ hyn_reset_proc(client, 40);
+
+ return 0;
+}
+
+static void cst3xx_report_contact(struct hynitron_ts_data *ts_data,
+ u8 id, unsigned int x, unsigned int y, u8 w)
+{
+ input_mt_slot(ts_data->input_dev, id);
+ input_mt_report_slot_state(ts_data->input_dev, MT_TOOL_FINGER, 1);
+ touchscreen_report_pos(ts_data->input_dev, &ts_data->prop, x, y, true);
+ input_report_abs(ts_data->input_dev, ABS_MT_TOUCH_MAJOR, w);
+}
+
+static int cst3xx_finish_touch_read(struct i2c_client *client)
+{
+ unsigned char buf[3];
+ int err;
+
+ put_unaligned_le24(CST3XX_TOUCH_DATA_STOP_CMD, buf);
+ err = cst3xx_i2c_write(client, buf, 3);
+ if (err) {
+ dev_err(&client->dev,
+ "send read touch info ending failed: %d\n", err);
+ return err;
+ }
+
+ return 0;
+}
+
+/*
+ * Handle events from IRQ. Note that for cst3xx it appears that IRQ
+ * fires continuously while touched, otherwise once every 1500ms
+ * when not touched (assume touchscreen waking up periodically).
+ * Note buffer is sized for 5 fingers, if more needed buffer must
+ * be increased. The buffer contains 5 bytes for each touch point,
+ * a touch count byte, a check byte, and then a second check byte after
+ * all other touch points.
+ *
+ * For example 1 touch would look like this:
+ * touch1[5]:touch_count[1]:chk_byte[1]
+ *
+ * 3 touches would look like this:
+ * touch1[5]:touch_count[1]:chk_byte[1]:touch2[5]:touch3[5]:chk_byte[1]
+ */
+static void cst3xx_touch_report(struct i2c_client *client)
+{
+ struct hynitron_ts_data *ts_data = i2c_get_clientdata(client);
+ u8 buf[28];
+ u8 finger_id, sw, w;
+ unsigned int x, y;
+ unsigned int touch_cnt, end_byte;
+ unsigned int idx = 0;
+ unsigned int i;
+ int err;
+
+ /* Read and validate the first bits of input data. */
+ err = cst3xx_i2c_read_register(client, CST3XX_TOUCH_DATA_PART_REG,
+ buf, 28);
+ if (err ||
+ buf[6] != CST3XX_TOUCH_DATA_CHK_VAL ||
+ buf[0] == CST3XX_TOUCH_DATA_CHK_VAL) {
+ dev_err(&client->dev, "cst3xx touch read failure\n");
+ return;
+ }
+
+ /* Report to the device we're done reading the touch data. */
+ err = cst3xx_finish_touch_read(client);
+ if (err)
+ return;
+
+ touch_cnt = buf[5] & CST3XX_TOUCH_COUNT_MASK;
+ /*
+ * Check the check bit of the last touch slot. The check bit is
+ * always present after touch point 1 for valid data, and then
+ * appears as the last byte after all other touch data.
+ */
+ if (touch_cnt > 1) {
+ end_byte = touch_cnt * 5 + 2;
+ if (buf[end_byte] != CST3XX_TOUCH_DATA_CHK_VAL) {
+ dev_err(&client->dev, "cst3xx touch read failure\n");
+ return;
+ }
+ }
+
+ /* Parse through the buffer to capture touch data. */
+ for (i = 0; i < touch_cnt; i++) {
+ x = ((buf[idx + 1] << 4) | ((buf[idx + 3] >> 4) & 0x0f));
+ y = ((buf[idx + 2] << 4) | (buf[idx + 3] & 0x0f));
+ w = (buf[idx + 4] >> 3);
+ sw = (buf[idx] & 0x0f) >> 1;
+ finger_id = (buf[idx] >> 4) & 0x0f;
+
+ /* Sanity check we don't have more fingers than we expect */
+ if (ts_data->chip->max_touch_num < finger_id) {
+ dev_err(&client->dev, "cst3xx touch read failure\n");
+ break;
+ }
+
+ /* sw value of 0 means no touch, 0x03 means touch */
+ if (sw == CST3XX_TOUCH_DATA_TOUCH_VAL)
+ cst3xx_report_contact(ts_data, finger_id, x, y, w);
+
+ idx += 5;
+
+ /* Skip the 2 bytes between point 1 and point 2 */
+ if (i == 0)
+ idx += 2;
+ }
+
+ input_mt_sync_frame(ts_data->input_dev);
+ input_sync(ts_data->input_dev);
+}
+
+static int cst3xx_input_dev_int(struct i2c_client *client)
+{
+ struct hynitron_ts_data *ts_data = i2c_get_clientdata(client);
+ int err;
+
+ ts_data->input_dev = devm_input_allocate_device(&client->dev);
+ if (!ts_data->input_dev) {
+ dev_err(&client->dev, "Failed to allocate input device\n");
+ return -ENOMEM;
+ }
+
+ ts_data->input_dev->name = "Hynitron cst3xx Touchscreen";
+ ts_data->input_dev->phys = "input/ts";
+ ts_data->input_dev->id.bustype = BUS_I2C;
+
+ input_set_drvdata(ts_data->input_dev, ts_data);
+
+ input_set_capability(ts_data->input_dev, EV_ABS, ABS_MT_POSITION_X);
+ input_set_capability(ts_data->input_dev, EV_ABS, ABS_MT_POSITION_Y);
+ input_set_abs_params(ts_data->input_dev, ABS_MT_TOUCH_MAJOR,
+ 0, 255, 0, 0);
+
+ touchscreen_parse_properties(ts_data->input_dev, true, &ts_data->prop);
+
+ if (!ts_data->prop.max_x || !ts_data->prop.max_y) {
+ dev_err(&client->dev,
+ "Invalid x/y (%d, %d), using defaults\n",
+ ts_data->prop.max_x, ts_data->prop.max_y);
+ ts_data->prop.max_x = 1152;
+ ts_data->prop.max_y = 1920;
+ input_abs_set_max(ts_data->input_dev,
+ ABS_MT_POSITION_X, ts_data->prop.max_x);
+ input_abs_set_max(ts_data->input_dev,
+ ABS_MT_POSITION_Y, ts_data->prop.max_y);
+ }
+
+ err = input_mt_init_slots(ts_data->input_dev,
+ ts_data->chip->max_touch_num,
+ INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
+ if (err) {
+ dev_err(&client->dev,
+ "Failed to initialize input slots: %d\n", err);
+ return err;
+ }
+
+ err = input_register_device(ts_data->input_dev);
+ if (err) {
+ dev_err(&client->dev,
+ "Input device registration failed: %d\n", err);
+ return err;
+ }
+
+ return 0;
+}
+
+static int hyn_probe(struct i2c_client *client)
+{
+ struct hynitron_ts_data *ts_data;
+ int err;
+
+ ts_data = devm_kzalloc(&client->dev, sizeof(*ts_data), GFP_KERNEL);
+ if (!ts_data)
+ return -ENOMEM;
+
+ ts_data->client = client;
+ i2c_set_clientdata(client, ts_data);
+
+ ts_data->chip = device_get_match_data(&client->dev);
+ if (!ts_data->chip)
+ return -EINVAL;
+
+ ts_data->reset_gpio = devm_gpiod_get(&client->dev,
+ "reset", GPIOD_OUT_LOW);
+ err = PTR_ERR_OR_ZERO(ts_data->reset_gpio);
+ if (err) {
+ dev_err(&client->dev, "request reset gpio failed: %d\n", err);
+ return err;
+ }
+
+ hyn_reset_proc(client, 60);
+
+ err = ts_data->chip->bootloader_enter(client);
+ if (err < 0)
+ return err;
+
+ err = ts_data->chip->init_input(client);
+ if (err < 0)
+ return err;
+
+ err = ts_data->chip->firmware_info(client);
+ if (err < 0)
+ return err;
+
+ err = devm_request_threaded_irq(&client->dev, client->irq,
+ NULL, hyn_interrupt_handler,
+ IRQF_ONESHOT,
+ "Hynitron Touch Int", client);
+ if (err) {
+ dev_err(&client->dev, "failed to request IRQ: %d\n", err);
+ return err;
+ }
+
+ return 0;
+}
+
+static const struct hynitron_ts_chip_data cst3xx_data = {
+ .max_touch_num = 5,
+ .ic_chkcode = 0xcaca0000,
+ .firmware_info = &cst3xx_firmware_info,
+ .bootloader_enter = &cst3xx_bootloader_enter,
+ .init_input = &cst3xx_input_dev_int,
+ .report_touch = &cst3xx_touch_report,
+};
+
+static const struct i2c_device_id hyn_tpd_id[] = {
+ { .name = "hynitron_ts", 0 },
+ { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(i2c, hyn_tpd_id);
+
+static const struct of_device_id hyn_dt_match[] = {
+ { .compatible = "hynitron,cst340", .data = &cst3xx_data },
+ { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, hyn_dt_match);
+
+static struct i2c_driver hynitron_i2c_driver = {
+ .driver = {
+ .name = "Hynitron-TS",
+ .of_match_table = hyn_dt_match,
+ .probe_type = PROBE_PREFER_ASYNCHRONOUS,
+ },
+ .id_table = hyn_tpd_id,
+ .probe = hyn_probe,
+};
+
+module_i2c_driver(hynitron_i2c_driver);
+
+MODULE_AUTHOR("Chris Morgan");
+MODULE_DESCRIPTION("Hynitron Touchscreen Driver");
+MODULE_LICENSE("GPL");