--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Microchip AT42QT1050 QTouch Sensor Controller
+ *
+ * Copyright (C) 2019 Pengutronix, Marco Felsch <kernel@pengutronix.de>
+ *
+ * Base on AT42QT1070 driver by:
+ * Bo Shen <voice.shen@atmel.com>
+ * Copyright (C) 2011 Atmel
+ */
+
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/log2.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/regmap.h>
+
+/* Chip ID */
+#define QT1050_CHIP_ID 0x00
+#define QT1050_CHIP_ID_VER 0x46
+
+/* Firmware version */
+#define QT1050_FW_VERSION 0x01
+
+/* Detection status */
+#define QT1050_DET_STATUS 0x02
+
+/* Key status */
+#define QT1050_KEY_STATUS 0x03
+
+/* Key Signals */
+#define QT1050_KEY_SIGNAL_0_MSB 0x06
+#define QT1050_KEY_SIGNAL_0_LSB 0x07
+#define QT1050_KEY_SIGNAL_1_MSB 0x08
+#define QT1050_KEY_SIGNAL_1_LSB 0x09
+#define QT1050_KEY_SIGNAL_2_MSB 0x0c
+#define QT1050_KEY_SIGNAL_2_LSB 0x0d
+#define QT1050_KEY_SIGNAL_3_MSB 0x0e
+#define QT1050_KEY_SIGNAL_3_LSB 0x0f
+#define QT1050_KEY_SIGNAL_4_MSB 0x10
+#define QT1050_KEY_SIGNAL_4_LSB 0x11
+
+/* Reference data */
+#define QT1050_REF_DATA_0_MSB 0x14
+#define QT1050_REF_DATA_0_LSB 0x15
+#define QT1050_REF_DATA_1_MSB 0x16
+#define QT1050_REF_DATA_1_LSB 0x17
+#define QT1050_REF_DATA_2_MSB 0x1a
+#define QT1050_REF_DATA_2_LSB 0x1b
+#define QT1050_REF_DATA_3_MSB 0x1c
+#define QT1050_REF_DATA_3_LSB 0x1d
+#define QT1050_REF_DATA_4_MSB 0x1e
+#define QT1050_REF_DATA_4_LSB 0x1f
+
+/* Negative threshold level */
+#define QT1050_NTHR_0 0x21
+#define QT1050_NTHR_1 0x22
+#define QT1050_NTHR_2 0x24
+#define QT1050_NTHR_3 0x25
+#define QT1050_NTHR_4 0x26
+
+/* Pulse / Scale */
+#define QT1050_PULSE_SCALE_0 0x28
+#define QT1050_PULSE_SCALE_1 0x29
+#define QT1050_PULSE_SCALE_2 0x2b
+#define QT1050_PULSE_SCALE_3 0x2c
+#define QT1050_PULSE_SCALE_4 0x2d
+
+/* Detection integrator counter / AKS */
+#define QT1050_DI_AKS_0 0x2f
+#define QT1050_DI_AKS_1 0x30
+#define QT1050_DI_AKS_2 0x32
+#define QT1050_DI_AKS_3 0x33
+#define QT1050_DI_AKS_4 0x34
+
+/* Charge Share Delay */
+#define QT1050_CSD_0 0x36
+#define QT1050_CSD_1 0x37
+#define QT1050_CSD_2 0x39
+#define QT1050_CSD_3 0x3a
+#define QT1050_CSD_4 0x3b
+
+/* Low Power Mode */
+#define QT1050_LPMODE 0x3d
+
+/* Calibration and Reset */
+#define QT1050_RES_CAL 0x3f
+#define QT1050_RES_CAL_RESET BIT(7)
+#define QT1050_RES_CAL_CALIBRATE BIT(1)
+
+#define QT1050_MAX_KEYS 5
+#define QT1050_RESET_TIME 255
+
+struct qt1050_key_regs {
+ unsigned int nthr;
+ unsigned int pulse_scale;
+ unsigned int di_aks;
+ unsigned int csd;
+};
+
+struct qt1050_key {
+ u32 num;
+ u32 charge_delay;
+ u32 thr_cnt;
+ u32 samples;
+ u32 scale;
+ u32 keycode;
+};
+
+struct qt1050_priv {
+ struct i2c_client *client;
+ struct input_dev *input;
+ struct regmap *regmap;
+ struct qt1050_key keys[QT1050_MAX_KEYS];
+ unsigned short keycodes[QT1050_MAX_KEYS];
+ u8 reg_keys;
+ u8 last_keys;
+};
+
+static const struct qt1050_key_regs qt1050_key_regs_data[] = {
+ {
+ .nthr = QT1050_NTHR_0,
+ .pulse_scale = QT1050_PULSE_SCALE_0,
+ .di_aks = QT1050_DI_AKS_0,
+ .csd = QT1050_CSD_0,
+ }, {
+ .nthr = QT1050_NTHR_1,
+ .pulse_scale = QT1050_PULSE_SCALE_1,
+ .di_aks = QT1050_DI_AKS_1,
+ .csd = QT1050_CSD_1,
+ }, {
+ .nthr = QT1050_NTHR_2,
+ .pulse_scale = QT1050_PULSE_SCALE_2,
+ .di_aks = QT1050_DI_AKS_2,
+ .csd = QT1050_CSD_2,
+ }, {
+ .nthr = QT1050_NTHR_3,
+ .pulse_scale = QT1050_PULSE_SCALE_3,
+ .di_aks = QT1050_DI_AKS_3,
+ .csd = QT1050_CSD_3,
+ }, {
+ .nthr = QT1050_NTHR_4,
+ .pulse_scale = QT1050_PULSE_SCALE_4,
+ .di_aks = QT1050_DI_AKS_4,
+ .csd = QT1050_CSD_4,
+ }
+};
+
+static bool qt1050_volatile_reg(struct device *dev, unsigned int reg)
+{
+ switch (reg) {
+ case QT1050_DET_STATUS:
+ case QT1050_KEY_STATUS:
+ case QT1050_KEY_SIGNAL_0_MSB:
+ case QT1050_KEY_SIGNAL_0_LSB:
+ case QT1050_KEY_SIGNAL_1_MSB:
+ case QT1050_KEY_SIGNAL_1_LSB:
+ case QT1050_KEY_SIGNAL_2_MSB:
+ case QT1050_KEY_SIGNAL_2_LSB:
+ case QT1050_KEY_SIGNAL_3_MSB:
+ case QT1050_KEY_SIGNAL_3_LSB:
+ case QT1050_KEY_SIGNAL_4_MSB:
+ case QT1050_KEY_SIGNAL_4_LSB:
+ return true;
+ default:
+ return false;
+ }
+}
+
+static const struct regmap_range qt1050_readable_ranges[] = {
+ regmap_reg_range(QT1050_CHIP_ID, QT1050_KEY_STATUS),
+ regmap_reg_range(QT1050_KEY_SIGNAL_0_MSB, QT1050_KEY_SIGNAL_1_LSB),
+ regmap_reg_range(QT1050_KEY_SIGNAL_2_MSB, QT1050_KEY_SIGNAL_4_LSB),
+ regmap_reg_range(QT1050_REF_DATA_0_MSB, QT1050_REF_DATA_1_LSB),
+ regmap_reg_range(QT1050_REF_DATA_2_MSB, QT1050_REF_DATA_4_LSB),
+ regmap_reg_range(QT1050_NTHR_0, QT1050_NTHR_1),
+ regmap_reg_range(QT1050_NTHR_2, QT1050_NTHR_4),
+ regmap_reg_range(QT1050_PULSE_SCALE_0, QT1050_PULSE_SCALE_1),
+ regmap_reg_range(QT1050_PULSE_SCALE_2, QT1050_PULSE_SCALE_4),
+ regmap_reg_range(QT1050_DI_AKS_0, QT1050_DI_AKS_1),
+ regmap_reg_range(QT1050_DI_AKS_2, QT1050_DI_AKS_4),
+ regmap_reg_range(QT1050_CSD_0, QT1050_CSD_1),
+ regmap_reg_range(QT1050_CSD_2, QT1050_RES_CAL),
+};
+
+static const struct regmap_access_table qt1050_readable_table = {
+ .yes_ranges = qt1050_readable_ranges,
+ .n_yes_ranges = ARRAY_SIZE(qt1050_readable_ranges),
+};
+
+static const struct regmap_range qt1050_writeable_ranges[] = {
+ regmap_reg_range(QT1050_NTHR_0, QT1050_NTHR_1),
+ regmap_reg_range(QT1050_NTHR_2, QT1050_NTHR_4),
+ regmap_reg_range(QT1050_PULSE_SCALE_0, QT1050_PULSE_SCALE_1),
+ regmap_reg_range(QT1050_PULSE_SCALE_2, QT1050_PULSE_SCALE_4),
+ regmap_reg_range(QT1050_DI_AKS_0, QT1050_DI_AKS_1),
+ regmap_reg_range(QT1050_DI_AKS_2, QT1050_DI_AKS_4),
+ regmap_reg_range(QT1050_CSD_0, QT1050_CSD_1),
+ regmap_reg_range(QT1050_CSD_2, QT1050_RES_CAL),
+};
+
+static const struct regmap_access_table qt1050_writeable_table = {
+ .yes_ranges = qt1050_writeable_ranges,
+ .n_yes_ranges = ARRAY_SIZE(qt1050_writeable_ranges),
+};
+
+static struct regmap_config qt1050_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .max_register = QT1050_RES_CAL,
+
+ .cache_type = REGCACHE_RBTREE,
+
+ .wr_table = &qt1050_writeable_table,
+ .rd_table = &qt1050_readable_table,
+ .volatile_reg = qt1050_volatile_reg,
+};
+
+static bool qt1050_identify(struct qt1050_priv *ts)
+{
+ unsigned int val;
+ int err;
+
+ /* Read Chip ID */
+ regmap_read(ts->regmap, QT1050_CHIP_ID, &val);
+ if (val != QT1050_CHIP_ID_VER) {
+ dev_err(&ts->client->dev, "ID %d not supported\n", val);
+ return false;
+ }
+
+ /* Read firmware version */
+ err = regmap_read(ts->regmap, QT1050_FW_VERSION, &val);
+ if (err) {
+ dev_err(&ts->client->dev, "could not read the firmware version\n");
+ return false;
+ }
+
+ dev_info(&ts->client->dev, "AT42QT1050 firmware version %1d.%1d\n",
+ val >> 4, val & 0xf);
+
+ return true;
+}
+
+static irqreturn_t qt1050_irq_threaded(int irq, void *dev_id)
+{
+ struct qt1050_priv *ts = dev_id;
+ struct input_dev *input = ts->input;
+ unsigned long new_keys, changed;
+ unsigned int val;
+ int i, err;
+
+ /* Read the detected status register, thus clearing interrupt */
+ err = regmap_read(ts->regmap, QT1050_DET_STATUS, &val);
+ if (err) {
+ dev_err(&ts->client->dev, "Fail to read detection status: %d\n",
+ err);
+ return IRQ_NONE;
+ }
+
+ /* Read which key changed, keys are not continuous */
+ err = regmap_read(ts->regmap, QT1050_KEY_STATUS, &val);
+ if (err) {
+ dev_err(&ts->client->dev,
+ "Fail to determine the key status: %d\n", err);
+ return IRQ_NONE;
+ }
+ new_keys = (val & 0x70) >> 2 | (val & 0x6) >> 1;
+ changed = ts->last_keys ^ new_keys;
+ /* Report registered keys only */
+ changed &= ts->reg_keys;
+
+ for_each_set_bit(i, &changed, QT1050_MAX_KEYS)
+ input_report_key(input, ts->keys[i].keycode,
+ test_bit(i, &new_keys));
+
+ ts->last_keys = new_keys;
+ input_sync(input);
+
+ return IRQ_HANDLED;
+}
+
+static const struct qt1050_key_regs *qt1050_get_key_regs(int key_num)
+{
+ return &qt1050_key_regs_data[key_num];
+}
+
+static int qt1050_set_key(struct regmap *map, int number, int on)
+{
+ const struct qt1050_key_regs *key_regs;
+
+ key_regs = qt1050_get_key_regs(number);
+
+ return regmap_update_bits(map, key_regs->di_aks, 0xfc,
+ on ? BIT(4) : 0x00);
+}
+
+static int qt1050_apply_fw_data(struct qt1050_priv *ts)
+{
+ struct regmap *map = ts->regmap;
+ struct qt1050_key *button = &ts->keys[0];
+ const struct qt1050_key_regs *key_regs;
+ int i, err;
+
+ /* Disable all keys and enable only the specified ones */
+ for (i = 0; i < QT1050_MAX_KEYS; i++) {
+ err = qt1050_set_key(map, i, 0);
+ if (err)
+ return err;
+ }
+
+ for (i = 0; i < QT1050_MAX_KEYS; i++, button++) {
+ /* Keep KEY_RESERVED keys off */
+ if (button->keycode == KEY_RESERVED)
+ continue;
+
+ err = qt1050_set_key(map, button->num, 1);
+ if (err)
+ return err;
+
+ key_regs = qt1050_get_key_regs(button->num);
+
+ err = regmap_write(map, key_regs->pulse_scale,
+ (button->samples << 4) | (button->scale));
+ if (err)
+ return err;
+ err = regmap_write(map, key_regs->csd, button->charge_delay);
+ if (err)
+ return err;
+ err = regmap_write(map, key_regs->nthr, button->thr_cnt);
+ if (err)
+ return err;
+ }
+
+ return 0;
+}
+
+static int qt1050_parse_fw(struct qt1050_priv *ts)
+{
+ struct device *dev = &ts->client->dev;
+ struct fwnode_handle *child;
+ int nbuttons;
+
+ nbuttons = device_get_child_node_count(dev);
+ if (nbuttons == 0 || nbuttons > QT1050_MAX_KEYS)
+ return -ENODEV;
+
+ device_for_each_child_node(dev, child) {
+ struct qt1050_key button;
+
+ /* Required properties */
+ if (fwnode_property_read_u32(child, "linux,code",
+ &button.keycode)) {
+ dev_err(dev, "Button without keycode\n");
+ goto err;
+ }
+ if (button.keycode >= KEY_MAX) {
+ dev_err(dev, "Invalid keycode 0x%x\n",
+ button.keycode);
+ goto err;
+ }
+
+ if (fwnode_property_read_u32(child, "reg",
+ &button.num)) {
+ dev_err(dev, "Button without pad number\n");
+ goto err;
+ }
+ if (button.num < 0 || button.num > QT1050_MAX_KEYS - 1)
+ goto err;
+
+ ts->reg_keys |= BIT(button.num);
+
+ /* Optional properties */
+ if (fwnode_property_read_u32(child,
+ "microchip,pre-charge-time-ns",
+ &button.charge_delay)) {
+ button.charge_delay = 0;
+ } else {
+ if (button.charge_delay % 2500 == 0)
+ button.charge_delay =
+ button.charge_delay / 2500;
+ else
+ button.charge_delay = 0;
+ }
+
+ if (fwnode_property_read_u32(child, "microchip,average-samples",
+ &button.samples)) {
+ button.samples = 0;
+ } else {
+ if (is_power_of_2(button.samples))
+ button.samples = ilog2(button.samples);
+ else
+ button.samples = 0;
+ }
+
+ if (fwnode_property_read_u32(child, "microchip,average-scaling",
+ &button.scale)) {
+ button.scale = 0;
+ } else {
+ if (is_power_of_2(button.scale))
+ button.scale = ilog2(button.scale);
+ else
+ button.scale = 0;
+
+ }
+
+ if (fwnode_property_read_u32(child, "microchip,threshold",
+ &button.thr_cnt)) {
+ button.thr_cnt = 20;
+ } else {
+ if (button.thr_cnt > 255)
+ button.thr_cnt = 20;
+ }
+
+ ts->keys[button.num] = button;
+ }
+
+ return 0;
+
+err:
+ fwnode_handle_put(child);
+ return -EINVAL;
+}
+
+static int qt1050_probe(struct i2c_client *client)
+{
+ struct qt1050_priv *ts;
+ struct input_dev *input;
+ struct device *dev = &client->dev;
+ struct regmap *map;
+ unsigned int status, i;
+ int err;
+
+ /* Check basic functionality */
+ err = i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE);
+ if (!err) {
+ dev_err(&client->dev, "%s adapter not supported\n",
+ dev_driver_string(&client->adapter->dev));
+ return -ENODEV;
+ }
+
+ if (!client->irq) {
+ dev_err(dev, "assign a irq line to this device\n");
+ return -EINVAL;
+ }
+
+ ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
+ if (!ts)
+ return -ENOMEM;
+
+ input = devm_input_allocate_device(dev);
+ if (!input)
+ return -ENOMEM;
+
+ map = devm_regmap_init_i2c(client, &qt1050_regmap_config);
+ if (IS_ERR(map))
+ return PTR_ERR(map);
+
+ ts->client = client;
+ ts->input = input;
+ ts->regmap = map;
+
+ i2c_set_clientdata(client, ts);
+
+ /* Identify the qt1050 chip */
+ if (!qt1050_identify(ts))
+ return -ENODEV;
+
+ /* Get pdata */
+ err = qt1050_parse_fw(ts);
+ if (err) {
+ dev_err(dev, "Failed to parse firmware: %d\n", err);
+ return err;
+ }
+
+ input->name = "AT42QT1050 QTouch Sensor";
+ input->dev.parent = &client->dev;
+ input->id.bustype = BUS_I2C;
+
+ /* Add the keycode */
+ input->keycode = ts->keycodes;
+ input->keycodesize = sizeof(ts->keycodes[0]);
+ input->keycodemax = QT1050_MAX_KEYS;
+
+ __set_bit(EV_KEY, input->evbit);
+ for (i = 0; i < QT1050_MAX_KEYS; i++) {
+ ts->keycodes[i] = ts->keys[i].keycode;
+ __set_bit(ts->keycodes[i], input->keybit);
+ }
+
+ /* Trigger re-calibration */
+ err = regmap_update_bits(ts->regmap, QT1050_RES_CAL, 0x7f,
+ QT1050_RES_CAL_CALIBRATE);
+ if (err) {
+ dev_err(dev, "Trigger calibration failed: %d\n", err);
+ return err;
+ }
+ err = regmap_read_poll_timeout(ts->regmap, QT1050_DET_STATUS, status,
+ status >> 7 == 1, 10000, 200000);
+ if (err) {
+ dev_err(dev, "Calibration failed: %d\n", err);
+ return err;
+ }
+
+ /* Soft reset to set defaults */
+ err = regmap_update_bits(ts->regmap, QT1050_RES_CAL,
+ QT1050_RES_CAL_RESET, QT1050_RES_CAL_RESET);
+ if (err) {
+ dev_err(dev, "Trigger soft reset failed: %d\n", err);
+ return err;
+ }
+ msleep(QT1050_RESET_TIME);
+
+ /* Set pdata */
+ err = qt1050_apply_fw_data(ts);
+ if (err) {
+ dev_err(dev, "Failed to set firmware data: %d\n", err);
+ return err;
+ }
+
+ err = devm_request_threaded_irq(dev, client->irq, NULL,
+ qt1050_irq_threaded, IRQF_ONESHOT,
+ "qt1050", ts);
+ if (err) {
+ dev_err(&client->dev, "Failed to request irq: %d\n", err);
+ return err;
+ }
+
+ /* Clear #CHANGE line */
+ err = regmap_read(ts->regmap, QT1050_DET_STATUS, &status);
+ if (err) {
+ dev_err(dev, "Failed to clear #CHANGE line level: %d\n", err);
+ return err;
+ }
+
+ /* Register the input device */
+ err = input_register_device(ts->input);
+ if (err) {
+ dev_err(&client->dev, "Failed to register input device: %d\n",
+ err);
+ return err;
+ }
+
+ return 0;
+}
+
+static int __maybe_unused qt1050_suspend(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct qt1050_priv *ts = i2c_get_clientdata(client);
+
+ disable_irq(client->irq);
+
+ /*
+ * Set measurement interval to 1s (125 x 8ms) if wakeup is allowed
+ * else turn off. The 1s interval seems to be a good compromise between
+ * low power and response time.
+ */
+ return regmap_write(ts->regmap, QT1050_LPMODE,
+ device_may_wakeup(dev) ? 125 : 0);
+}
+
+static int __maybe_unused qt1050_resume(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct qt1050_priv *ts = i2c_get_clientdata(client);
+
+ enable_irq(client->irq);
+
+ /* Set measurement interval back to 16ms (2 x 8ms) */
+ return regmap_write(ts->regmap, QT1050_LPMODE, 2);
+}
+
+static SIMPLE_DEV_PM_OPS(qt1050_pm_ops, qt1050_suspend, qt1050_resume);
+
+static const struct of_device_id __maybe_unused qt1050_of_match[] = {
+ { .compatible = "microchip,qt1050", },
+ { },
+};
+MODULE_DEVICE_TABLE(of, qt1050_of_match);
+
+static struct i2c_driver qt1050_driver = {
+ .driver = {
+ .name = "qt1050",
+ .of_match_table = of_match_ptr(qt1050_of_match),
+ .pm = &qt1050_pm_ops,
+ },
+ .probe_new = qt1050_probe,
+};
+
+module_i2c_driver(qt1050_driver);
+
+MODULE_AUTHOR("Marco Felsch <kernel@pengutronix.de");
+MODULE_DESCRIPTION("Driver for AT42QT1050 QTouch sensor");
+MODULE_LICENSE("GPL v2");
projects / platform / kernel / linux-rpi.git / commitdiff