@@ -0,0 +1,223 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Cypress StreetFighter Touchkey Driver
+ *
+ * Copyright (c) 2021 Yassine Oudjana <y.oudjana@protonmail.com>
+ */
+
+#include <linux/bitops.h>
+#include <linux/device.h>
+#include <linux/i2c.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/pm.h>
+#include <linux/regulator/consumer.h>
+
+#define CYPRESS_SF_DEV_NAME "cypress-sf"
+
+#define CYPRESS_SF_REG_FW_VERSION 0x46
+#define CYPRESS_SF_REG_HW_VERSION 0x48
+#define CYPRESS_SF_REG_BUTTON_STATUS 0x4a
+
+struct cypress_sf_data {
+ struct i2c_client *client;
+ struct input_dev *input_dev;
+ struct regulator_bulk_data regulators[2];
+ u32 *keycodes;
+ unsigned long keystates;
+ int num_keys;
+};
+
+static irqreturn_t cypress_sf_irq_handler(int irq, void *devid)
+{
+ struct cypress_sf_data *touchkey = devid;
+ unsigned long keystates;
+ bool curr_state, new_state;
+ int key;
+
+ keystates = i2c_smbus_read_byte_data(touchkey->client,
+ CYPRESS_SF_REG_BUTTON_STATUS);
+ if (keystates < 0) {
+ dev_err(&touchkey->client->dev, "Failed to read button status");
+ return IRQ_NONE;
+ }
+
+ for(key = 0; key < touchkey->num_keys; ++key) {
+ curr_state = test_bit(key, &touchkey->keystates);
+ new_state = test_bit(key, &keystates);
+
+ if(curr_state ^ new_state) {
+ dev_dbg(&touchkey->client->dev,\
+ "Key %d changed to %d", key, new_state);
+ input_report_key(touchkey->input_dev,
+ touchkey->keycodes[key],
+ new_state);
+ }
+ }
+ input_sync(touchkey->input_dev);
+ touchkey->keystates = keystates;
+
+ return IRQ_HANDLED;
+}
+
+static int cypress_sf_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct cypress_sf_data *touchkey;
+ int hw_version, fw_version;
+ int i, ret;
+
+ touchkey = devm_kzalloc(&client->dev, sizeof(*touchkey), GFP_KERNEL);
+ if(!touchkey)
+ return -ENOMEM;
+
+ touchkey->client = client;
+ i2c_set_clientdata(client, touchkey);
+
+ touchkey->regulators[0].supply = "vdd";
+ touchkey->regulators[1].supply = "avdd";
+
+ ret = devm_regulator_bulk_get(&client->dev,
+ ARRAY_SIZE(touchkey->regulators),
+ touchkey->regulators);
+ if(ret) {
+ dev_err(&client->dev, "Failed to get regulators: %d\n", ret);
+ return ret;
+ }
+
+ touchkey->num_keys = of_property_count_elems_of_size(client->dev.of_node,
+ "linux,keycodes",
+ sizeof(u32));
+ if(touchkey->num_keys < 0)
+ /* Default key count */
+ touchkey->num_keys = 2;
+
+ touchkey->keycodes = devm_kzalloc(&client->dev,
+ sizeof(u32) * touchkey->num_keys, GFP_KERNEL);
+ if(!touchkey->keycodes)
+ return -ENOMEM;
+
+ ret = of_property_read_u32_array(client->dev.of_node, "linux,keycodes",
+ touchkey->keycodes, touchkey->num_keys);
+
+ if(touchkey->num_keys < 0) {
+ /* Default keycodes */
+ touchkey->keycodes[0] = KEY_BACK;
+ touchkey->keycodes[1] = KEY_MENU;
+ }
+
+ ret = regulator_bulk_enable(ARRAY_SIZE(touchkey->regulators),
+ touchkey->regulators);
+ if(ret) {
+ dev_err(&client->dev, "Failed to enable regulators: %d\n", ret);
+ return ret;
+ }
+
+ touchkey->input_dev = devm_input_allocate_device(&client->dev);
+ if(!touchkey->input_dev) {
+ dev_err(&client->dev, "Failed to allocate input device\n");
+ return -ENOMEM;
+ }
+
+ touchkey->input_dev->name = CYPRESS_SF_DEV_NAME;
+ touchkey->input_dev->id.bustype = BUS_I2C;
+
+ hw_version = i2c_smbus_read_byte_data(touchkey->client,
+ CYPRESS_SF_REG_HW_VERSION);
+ fw_version = i2c_smbus_read_word_data(touchkey->client,
+ CYPRESS_SF_REG_FW_VERSION);
+ if(hw_version < 0 || fw_version < 0)
+ dev_warn(&client->dev, "Failed to read versions\n");
+ else
+ dev_info(&client->dev, "HW version %d, FW version %d\n",
+ hw_version, fw_version);
+
+ for(i = 0; i < touchkey->num_keys; ++i)
+ input_set_capability(touchkey->input_dev, EV_KEY,
+ touchkey->keycodes[i]);
+
+ ret = input_register_device(touchkey->input_dev);
+ if(ret) {
+ dev_err(&client->dev,
+ "Failed to register input device: %d\n", ret);
+ return ret;
+ }
+
+ ret = devm_request_threaded_irq(&client->dev, client->irq,
+ NULL, cypress_sf_irq_handler,
+ IRQF_ONESHOT,
+ CYPRESS_SF_DEV_NAME, touchkey);
+ if(ret) {
+ dev_err(&client->dev,
+ "Failed to register threaded irq: %d", ret);
+ return ret;
+ }
+
+ return 0;
+};
+
+static int __maybe_unused cypress_sf_suspend(struct device *dev) {
+ struct i2c_client *client = to_i2c_client(dev);
+ struct cypress_sf_data *touchkey = i2c_get_clientdata(client);
+ int ret;
+
+ disable_irq(client->irq);
+ ret = regulator_bulk_disable(ARRAY_SIZE(touchkey->regulators),
+ touchkey->regulators);
+ if(ret) {
+ dev_err(dev, "Failed to disable regulators: %d", ret);
+ enable_irq(client->irq);
+ return ret;
+ }
+ dev_dbg(dev, "Suspended device");
+
+ return 0;
+}
+
+static int __maybe_unused cypress_sf_resume(struct device *dev) {
+ struct i2c_client *client = to_i2c_client(dev);
+ struct cypress_sf_data *touchkey = i2c_get_clientdata(client);
+ int ret;
+
+ ret = regulator_bulk_enable(ARRAY_SIZE(touchkey->regulators),
+ touchkey->regulators);
+ if(ret) {
+ dev_err(dev, "Failed to enable regulators: %d", ret);
+ return ret;
+ }
+ enable_irq(client->irq);
+ dev_dbg(dev, "Resumed device");
+
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(cypress_sf_pm_ops,
+ cypress_sf_suspend, cypress_sf_resume);
+
+static struct i2c_device_id cypress_sf_id_table[] = {
+ { CYPRESS_SF_DEV_NAME, 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, cypress_sf_id_table);
+
+static const struct of_device_id cypress_sf_of_match[] = {
+ { .compatible = "cypress,sf3155", },
+ { },
+};
+MODULE_DEVICE_TABLE(of, cypress_sf_of_match);
+
+static struct i2c_driver cypress_sf_driver = {
+ .driver = {
+ .name = CYPRESS_SF_DEV_NAME,
+ .pm = &cypress_sf_pm_ops,
+ .of_match_table = of_match_ptr(cypress_sf_of_match),
+ },
+ .id_table = cypress_sf_id_table,
+ .probe = cypress_sf_probe,
+};
+module_i2c_driver(cypress_sf_driver);
+
+MODULE_AUTHOR("Yassine Oudjana <y.oudjana@protonmail.com>");
+MODULE_DESCRIPTION("Cypress StreetFighter Touchkey Driver");
+MODULE_LICENSE("GPL v2");