1 files changed, 400 insertions, 0 deletions
diff --git a/drivers/input/keyboard/mpr121_touchkey.c b/drivers/input/keyboard/mpr121_touchkey.c
new file mode 100644
index 000000000..230ab3d50
--- /dev/null
+++ b/drivers/input/keyboard/mpr121_touchkey.c
@@ -0,0 +1,400 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Touchkey driver for Freescale MPR121 Controllor
+ *
+ * Copyright (C) 2011 Freescale Semiconductor, Inc.
+ * Author: Zhang Jiejing <jiejing.zhang@freescale.com>
+ *
+ * Based on mcs_touchkey.c
+ */
+
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/property.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+
+/* Register definitions */
+#define ELE_TOUCH_STATUS_0_ADDR	0x0
+#define ELE_TOUCH_STATUS_1_ADDR	0X1
+#define MHD_RISING_ADDR		0x2b
+#define NHD_RISING_ADDR		0x2c
+#define NCL_RISING_ADDR		0x2d
+#define FDL_RISING_ADDR		0x2e
+#define MHD_FALLING_ADDR	0x2f
+#define NHD_FALLING_ADDR	0x30
+#define NCL_FALLING_ADDR	0x31
+#define FDL_FALLING_ADDR	0x32
+#define ELE0_TOUCH_THRESHOLD_ADDR	0x41
+#define ELE0_RELEASE_THRESHOLD_ADDR	0x42
+#define AFE_CONF_ADDR			0x5c
+#define FILTER_CONF_ADDR		0x5d
+
+/*
+ * ELECTRODE_CONF_ADDR: This register configures the number of
+ * enabled capacitance sensing inputs and its run/suspend mode.
+ */
+#define ELECTRODE_CONF_ADDR		0x5e
+#define ELECTRODE_CONF_QUICK_CHARGE	0x80
+#define AUTO_CONFIG_CTRL_ADDR		0x7b
+#define AUTO_CONFIG_USL_ADDR		0x7d
+#define AUTO_CONFIG_LSL_ADDR		0x7e
+#define AUTO_CONFIG_TL_ADDR		0x7f
+
+/* Threshold of touch/release trigger */
+#define TOUCH_THRESHOLD			0x08
+#define RELEASE_THRESHOLD		0x05
+/* Masks for touch and release triggers */
+#define TOUCH_STATUS_MASK		0xfff
+/* MPR121 has 12 keys */
+#define MPR121_MAX_KEY_COUNT		12
+
+#define MPR121_MIN_POLL_INTERVAL	10
+#define MPR121_MAX_POLL_INTERVAL	200
+
+struct mpr121_touchkey {
+	struct i2c_client	*client;
+	struct input_dev	*input_dev;
+	unsigned int		statusbits;
+	unsigned int		keycount;
+	u32			keycodes[MPR121_MAX_KEY_COUNT];
+};
+
+struct mpr121_init_register {
+	int addr;
+	u8 val;
+};
+
+static const struct mpr121_init_register init_reg_table[] = {
+	{ MHD_RISING_ADDR,	0x1 },
+	{ NHD_RISING_ADDR,	0x1 },
+	{ MHD_FALLING_ADDR,	0x1 },
+	{ NHD_FALLING_ADDR,	0x1 },
+	{ NCL_FALLING_ADDR,	0xff },
+	{ FDL_FALLING_ADDR,	0x02 },
+	{ FILTER_CONF_ADDR,	0x04 },
+	{ AFE_CONF_ADDR,	0x0b },
+	{ AUTO_CONFIG_CTRL_ADDR, 0x0b },
+};
+
+static void mpr121_vdd_supply_disable(void *data)
+{
+	struct regulator *vdd_supply = data;
+
+	regulator_disable(vdd_supply);
+}
+
+static struct regulator *mpr121_vdd_supply_init(struct device *dev)
+{
+	struct regulator *vdd_supply;
+	int err;
+
+	vdd_supply = devm_regulator_get(dev, "vdd");
+	if (IS_ERR(vdd_supply)) {
+		dev_err(dev, "failed to get vdd regulator: %ld\n",
+			PTR_ERR(vdd_supply));
+		return vdd_supply;
+	}
+
+	err = regulator_enable(vdd_supply);
+	if (err) {
+		dev_err(dev, "failed to enable vdd regulator: %d\n", err);
+		return ERR_PTR(err);
+	}
+
+	err = devm_add_action_or_reset(dev, mpr121_vdd_supply_disable,
+				       vdd_supply);
+	if (err) {
+		dev_err(dev, "failed to add disable regulator action: %d\n",
+			err);
+		return ERR_PTR(err);
+	}
+
+	return vdd_supply;
+}
+
+static void mpr_touchkey_report(struct input_dev *dev)
+{
+	struct mpr121_touchkey *mpr121 = input_get_drvdata(dev);
+	struct input_dev *input = mpr121->input_dev;
+	struct i2c_client *client = mpr121->client;
+	unsigned long bit_changed;
+	unsigned int key_num;
+	int reg;
+
+	reg = i2c_smbus_read_byte_data(client, ELE_TOUCH_STATUS_1_ADDR);
+	if (reg < 0) {
+		dev_err(&client->dev, "i2c read error [%d]\n", reg);
+		return;
+	}
+
+	reg <<= 8;
+	reg |= i2c_smbus_read_byte_data(client, ELE_TOUCH_STATUS_0_ADDR);
+	if (reg < 0) {
+		dev_err(&client->dev, "i2c read error [%d]\n", reg);
+		return;
+	}
+
+	reg &= TOUCH_STATUS_MASK;
+	/* use old press bit to figure out which bit changed */
+	bit_changed = reg ^ mpr121->statusbits;
+	mpr121->statusbits = reg;
+	for_each_set_bit(key_num, &bit_changed, mpr121->keycount) {
+		unsigned int key_val, pressed;
+
+		pressed = reg & BIT(key_num);
+		key_val = mpr121->keycodes[key_num];
+
+		input_event(input, EV_MSC, MSC_SCAN, key_num);
+		input_report_key(input, key_val, pressed);
+
+		dev_dbg(&client->dev, "key %d %d %s\n", key_num, key_val,
+			pressed ? "pressed" : "released");
+
+	}
+	input_sync(input);
+}
+
+static irqreturn_t mpr_touchkey_interrupt(int irq, void *dev_id)
+{
+	struct mpr121_touchkey *mpr121 = dev_id;
+
+	mpr_touchkey_report(mpr121->input_dev);
+
+	return IRQ_HANDLED;
+}
+
+static int mpr121_phys_init(struct mpr121_touchkey *mpr121,
+			    struct i2c_client *client, int vdd_uv)
+{
+	const struct mpr121_init_register *reg;
+	unsigned char usl, lsl, tl, eleconf;
+	int i, t, vdd, ret;
+
+	/* Set up touch/release threshold for ele0-ele11 */
+	for (i = 0; i <= MPR121_MAX_KEY_COUNT; i++) {
+		t = ELE0_TOUCH_THRESHOLD_ADDR + (i * 2);
+		ret = i2c_smbus_write_byte_data(client, t, TOUCH_THRESHOLD);
+		if (ret < 0)
+			goto err_i2c_write;
+		ret = i2c_smbus_write_byte_data(client, t + 1,
+						RELEASE_THRESHOLD);
+		if (ret < 0)
+			goto err_i2c_write;
+	}
+
+	/* Set up init register */
+	for (i = 0; i < ARRAY_SIZE(init_reg_table); i++) {
+		reg = &init_reg_table[i];
+		ret = i2c_smbus_write_byte_data(client, reg->addr, reg->val);
+		if (ret < 0)
+			goto err_i2c_write;
+	}
+
+
+	/*
+	 * Capacitance on sensing input varies and needs to be compensated.
+	 * The internal MPR121-auto-configuration can do this if it's
+	 * registers are set properly (based on vdd_uv).
+	 */
+	vdd = vdd_uv / 1000;
+	usl = ((vdd - 700) * 256) / vdd;
+	lsl = (usl * 65) / 100;
+	tl = (usl * 90) / 100;
+	ret = i2c_smbus_write_byte_data(client, AUTO_CONFIG_USL_ADDR, usl);
+	ret |= i2c_smbus_write_byte_data(client, AUTO_CONFIG_LSL_ADDR, lsl);
+	ret |= i2c_smbus_write_byte_data(client, AUTO_CONFIG_TL_ADDR, tl);
+
+	/*
+	 * Quick charge bit will let the capacitive charge to ready
+	 * state quickly, or the buttons may not function after system
+	 * boot.
+	 */
+	eleconf = mpr121->keycount | ELECTRODE_CONF_QUICK_CHARGE;
+	ret |= i2c_smbus_write_byte_data(client, ELECTRODE_CONF_ADDR,
+					 eleconf);
+	if (ret != 0)
+		goto err_i2c_write;
+
+	dev_dbg(&client->dev, "set up with %x keys.\n", mpr121->keycount);
+
+	return 0;
+
+err_i2c_write:
+	dev_err(&client->dev, "i2c write error: %d\n", ret);
+	return ret;
+}
+
+static int mpr_touchkey_probe(struct i2c_client *client,
+			      const struct i2c_device_id *id)
+{
+	struct device *dev = &client->dev;
+	struct regulator *vdd_supply;
+	int vdd_uv;
+	struct mpr121_touchkey *mpr121;
+	struct input_dev *input_dev;
+	u32 poll_interval = 0;
+	int error;
+	int i;
+
+	vdd_supply = mpr121_vdd_supply_init(dev);
+	if (IS_ERR(vdd_supply))
+		return PTR_ERR(vdd_supply);
+
+	vdd_uv = regulator_get_voltage(vdd_supply);
+
+	mpr121 = devm_kzalloc(dev, sizeof(*mpr121), GFP_KERNEL);
+	if (!mpr121)
+		return -ENOMEM;
+
+	input_dev = devm_input_allocate_device(dev);
+	if (!input_dev)
+		return -ENOMEM;
+
+	mpr121->client = client;
+	mpr121->input_dev = input_dev;
+	mpr121->keycount = device_property_count_u32(dev, "linux,keycodes");
+	if (mpr121->keycount > MPR121_MAX_KEY_COUNT) {
+		dev_err(dev, "too many keys defined (%d)\n", mpr121->keycount);
+		return -EINVAL;
+	}
+
+	error = device_property_read_u32_array(dev, "linux,keycodes",
+					       mpr121->keycodes,
+					       mpr121->keycount);
+	if (error) {
+		dev_err(dev,
+			"failed to read linux,keycode property: %d\n", error);
+		return error;
+	}
+
+	input_dev->name = "Freescale MPR121 Touchkey";
+	input_dev->id.bustype = BUS_I2C;
+	input_dev->dev.parent = dev;
+	if (device_property_read_bool(dev, "autorepeat"))
+		__set_bit(EV_REP, input_dev->evbit);
+	input_set_capability(input_dev, EV_MSC, MSC_SCAN);
+	input_set_drvdata(input_dev, mpr121);
+
+	input_dev->keycode = mpr121->keycodes;
+	input_dev->keycodesize = sizeof(mpr121->keycodes[0]);
+	input_dev->keycodemax = mpr121->keycount;
+
+	for (i = 0; i < mpr121->keycount; i++)
+		input_set_capability(input_dev, EV_KEY, mpr121->keycodes[i]);
+
+	error = mpr121_phys_init(mpr121, client, vdd_uv);
+	if (error) {
+		dev_err(dev, "Failed to init register\n");
+		return error;
+	}
+
+	device_property_read_u32(dev, "poll-interval", &poll_interval);
+
+	if (client->irq) {
+		error = devm_request_threaded_irq(dev, client->irq, NULL,
+						  mpr_touchkey_interrupt,
+						  IRQF_TRIGGER_FALLING |
+						  IRQF_ONESHOT,
+						  dev->driver->name, mpr121);
+		if (error) {
+			dev_err(dev, "Failed to register interrupt\n");
+			return error;
+		}
+	} else if (poll_interval) {
+		if (poll_interval < MPR121_MIN_POLL_INTERVAL)
+			return -EINVAL;
+
+		if (poll_interval > MPR121_MAX_POLL_INTERVAL)
+			return -EINVAL;
+
+		error = input_setup_polling(input_dev, mpr_touchkey_report);
+		if (error) {
+			dev_err(dev, "Failed to setup polling\n");
+			return error;
+		}
+
+		input_set_poll_interval(input_dev, poll_interval);
+		input_set_min_poll_interval(input_dev,
+					    MPR121_MIN_POLL_INTERVAL);
+		input_set_max_poll_interval(input_dev,
+					    MPR121_MAX_POLL_INTERVAL);
+	} else {
+		dev_err(dev,
+			"invalid IRQ number and polling not configured\n");
+		return -EINVAL;
+	}
+
+	error = input_register_device(input_dev);
+	if (error)
+		return error;
+
+	i2c_set_clientdata(client, mpr121);
+	device_init_wakeup(dev,
+			device_property_read_bool(dev, "wakeup-source"));
+
+	return 0;
+}
+
+static int __maybe_unused mpr_suspend(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+
+	if (device_may_wakeup(&client->dev))
+		enable_irq_wake(client->irq);
+
+	i2c_smbus_write_byte_data(client, ELECTRODE_CONF_ADDR, 0x00);
+
+	return 0;
+}
+
+static int __maybe_unused mpr_resume(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct mpr121_touchkey *mpr121 = i2c_get_clientdata(client);
+
+	if (device_may_wakeup(&client->dev))
+		disable_irq_wake(client->irq);
+
+	i2c_smbus_write_byte_data(client, ELECTRODE_CONF_ADDR,
+				  mpr121->keycount);
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(mpr121_touchkey_pm_ops, mpr_suspend, mpr_resume);
+
+static const struct i2c_device_id mpr121_id[] = {
+	{ "mpr121_touchkey", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, mpr121_id);
+
+#ifdef CONFIG_OF
+static const struct of_device_id mpr121_touchkey_dt_match_table[] = {
+	{ .compatible = "fsl,mpr121-touchkey" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, mpr121_touchkey_dt_match_table);
+#endif
+
+static struct i2c_driver mpr_touchkey_driver = {
+	.driver = {
+		.name	= "mpr121",
+		.pm	= &mpr121_touchkey_pm_ops,
+		.of_match_table = of_match_ptr(mpr121_touchkey_dt_match_table),
+	},
+	.id_table	= mpr121_id,
+	.probe		= mpr_touchkey_probe,
+};
+
+module_i2c_driver(mpr_touchkey_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Zhang Jiejing <jiejing.zhang@freescale.com>");
+MODULE_DESCRIPTION("Touch Key driver for Freescale MPR121 Chip");