File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/drivers/input/keyboard/tca8418_keypad.c b/drivers/input/keyboard/tca8418_keypad.c
new file mode 100644
index 0000000..9002298
--- /dev/null
+++ b/drivers/input/keyboard/tca8418_keypad.c
@@ -0,0 +1,427 @@
+/*
+ * Driver for TCA8418 I2C keyboard
+ *
+ * Copyright (C) 2011 Fuel7, Inc.  All rights reserved.
+ *
+ * Author: Kyle Manna <kyle.manna@fuel7.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ *
+ * If you can't comply with GPLv2, alternative licensing terms may be
+ * arranged. Please contact Fuel7, Inc. (http://fuel7.com/) for proprietary
+ * alternative licensing inquiries.
+ */
+
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/workqueue.h>
+#include <linux/gpio.h>
+#include <linux/i2c.h>
+#include <linux/input.h>
+#include <linux/input/tca8418_keypad.h>
+#include <linux/of.h>
+
+/* TCA8418 hardware limits */
+#define TCA8418_MAX_ROWS	8
+#define TCA8418_MAX_COLS	10
+
+/* TCA8418 register offsets */
+#define REG_CFG			0x01
+#define REG_INT_STAT		0x02
+#define REG_KEY_LCK_EC		0x03
+#define REG_KEY_EVENT_A		0x04
+#define REG_KEY_EVENT_B		0x05
+#define REG_KEY_EVENT_C		0x06
+#define REG_KEY_EVENT_D		0x07
+#define REG_KEY_EVENT_E		0x08
+#define REG_KEY_EVENT_F		0x09
+#define REG_KEY_EVENT_G		0x0A
+#define REG_KEY_EVENT_H		0x0B
+#define REG_KEY_EVENT_I		0x0C
+#define REG_KEY_EVENT_J		0x0D
+#define REG_KP_LCK_TIMER	0x0E
+#define REG_UNLOCK1		0x0F
+#define REG_UNLOCK2		0x10
+#define REG_GPIO_INT_STAT1	0x11
+#define REG_GPIO_INT_STAT2	0x12
+#define REG_GPIO_INT_STAT3	0x13
+#define REG_GPIO_DAT_STAT1	0x14
+#define REG_GPIO_DAT_STAT2	0x15
+#define REG_GPIO_DAT_STAT3	0x16
+#define REG_GPIO_DAT_OUT1	0x17
+#define REG_GPIO_DAT_OUT2	0x18
+#define REG_GPIO_DAT_OUT3	0x19
+#define REG_GPIO_INT_EN1	0x1A
+#define REG_GPIO_INT_EN2	0x1B
+#define REG_GPIO_INT_EN3	0x1C
+#define REG_KP_GPIO1		0x1D
+#define REG_KP_GPIO2		0x1E
+#define REG_KP_GPIO3		0x1F
+#define REG_GPI_EM1		0x20
+#define REG_GPI_EM2		0x21
+#define REG_GPI_EM3		0x22
+#define REG_GPIO_DIR1		0x23
+#define REG_GPIO_DIR2		0x24
+#define REG_GPIO_DIR3		0x25
+#define REG_GPIO_INT_LVL1	0x26
+#define REG_GPIO_INT_LVL2	0x27
+#define REG_GPIO_INT_LVL3	0x28
+#define REG_DEBOUNCE_DIS1	0x29
+#define REG_DEBOUNCE_DIS2	0x2A
+#define REG_DEBOUNCE_DIS3	0x2B
+#define REG_GPIO_PULL1		0x2C
+#define REG_GPIO_PULL2		0x2D
+#define REG_GPIO_PULL3		0x2E
+
+/* TCA8418 bit definitions */
+#define CFG_AI			BIT(7)
+#define CFG_GPI_E_CFG		BIT(6)
+#define CFG_OVR_FLOW_M		BIT(5)
+#define CFG_INT_CFG		BIT(4)
+#define CFG_OVR_FLOW_IEN	BIT(3)
+#define CFG_K_LCK_IEN		BIT(2)
+#define CFG_GPI_IEN		BIT(1)
+#define CFG_KE_IEN		BIT(0)
+
+#define INT_STAT_CAD_INT	BIT(4)
+#define INT_STAT_OVR_FLOW_INT	BIT(3)
+#define INT_STAT_K_LCK_INT	BIT(2)
+#define INT_STAT_GPI_INT	BIT(1)
+#define INT_STAT_K_INT		BIT(0)
+
+/* TCA8418 register masks */
+#define KEY_LCK_EC_KEC		0x7
+#define KEY_EVENT_CODE		0x7f
+#define KEY_EVENT_VALUE		0x80
+
+struct tca8418_keypad {
+	struct i2c_client *client;
+	struct input_dev *input;
+
+	unsigned int row_shift;
+};
+
+/*
+ * Write a byte to the TCA8418
+ */
+static int tca8418_write_byte(struct tca8418_keypad *keypad_data,
+			      int reg, u8 val)
+{
+	int error;
+
+	error = i2c_smbus_write_byte_data(keypad_data->client, reg, val);
+	if (error < 0) {
+		dev_err(&keypad_data->client->dev,
+			"%s failed, reg: %d, val: %d, error: %d\n",
+			__func__, reg, val, error);
+		return error;
+	}
+
+	return 0;
+}
+
+/*
+ * Read a byte from the TCA8418
+ */
+static int tca8418_read_byte(struct tca8418_keypad *keypad_data,
+			     int reg, u8 *val)
+{
+	int error;
+
+	error = i2c_smbus_read_byte_data(keypad_data->client, reg);
+	if (error < 0) {
+		dev_err(&keypad_data->client->dev,
+				"%s failed, reg: %d, error: %d\n",
+				__func__, reg, error);
+		return error;
+	}
+
+	*val = (u8)error;
+
+	return 0;
+}
+
+static void tca8418_read_keypad(struct tca8418_keypad *keypad_data)
+{
+	struct input_dev *input = keypad_data->input;
+	unsigned short *keymap = input->keycode;
+	int error, col, row;
+	u8 reg, state, code;
+
+	/* Initial read of the key event FIFO */
+	error = tca8418_read_byte(keypad_data, REG_KEY_EVENT_A, &reg);
+
+	/* Assume that key code 0 signifies empty FIFO */
+	while (error >= 0 && reg > 0) {
+		state = reg & KEY_EVENT_VALUE;
+		code  = reg & KEY_EVENT_CODE;
+
+		row = code / TCA8418_MAX_COLS;
+		col = code % TCA8418_MAX_COLS;
+
+		row = (col) ? row : row - 1;
+		col = (col) ? col - 1 : TCA8418_MAX_COLS - 1;
+
+		code = MATRIX_SCAN_CODE(row, col, keypad_data->row_shift);
+		input_event(input, EV_MSC, MSC_SCAN, code);
+		input_report_key(input, keymap[code], state);
+
+		/* Read for next loop */
+		error = tca8418_read_byte(keypad_data, REG_KEY_EVENT_A, &reg);
+	}
+
+	if (error < 0)
+		dev_err(&keypad_data->client->dev,
+			"unable to read REG_KEY_EVENT_A\n");
+
+	input_sync(input);
+}
+
+/*
+ * Threaded IRQ handler and this can (and will) sleep.
+ */
+static irqreturn_t tca8418_irq_handler(int irq, void *dev_id)
+{
+	struct tca8418_keypad *keypad_data = dev_id;
+	u8 reg;
+	int error;
+
+	error = tca8418_read_byte(keypad_data, REG_INT_STAT, &reg);
+	if (error) {
+		dev_err(&keypad_data->client->dev,
+			"unable to read REG_INT_STAT\n");
+		return IRQ_NONE;
+	}
+
+	if (!reg)
+		return IRQ_NONE;
+
+	if (reg & INT_STAT_OVR_FLOW_INT)
+		dev_warn(&keypad_data->client->dev, "overflow occurred\n");
+
+	if (reg & INT_STAT_K_INT)
+		tca8418_read_keypad(keypad_data);
+
+	/* Clear all interrupts, even IRQs we didn't check (GPI, CAD, LCK) */
+	reg = 0xff;
+	error = tca8418_write_byte(keypad_data, REG_INT_STAT, reg);
+	if (error)
+		dev_err(&keypad_data->client->dev,
+			"unable to clear REG_INT_STAT\n");
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * Configure the TCA8418 for keypad operation
+ */
+static int tca8418_configure(struct tca8418_keypad *keypad_data,
+			     u32 rows, u32 cols)
+{
+	int reg, error;
+
+	/* Write config register, if this fails assume device not present */
+	error = tca8418_write_byte(keypad_data, REG_CFG,
+				CFG_INT_CFG | CFG_OVR_FLOW_IEN | CFG_KE_IEN);
+	if (error < 0)
+		return -ENODEV;
+
+
+	/* Assemble a mask for row and column registers */
+	reg  =  ~(~0 << rows);
+	reg += (~(~0 << cols)) << 8;
+
+	/* Set registers to keypad mode */
+	error |= tca8418_write_byte(keypad_data, REG_KP_GPIO1, reg);
+	error |= tca8418_write_byte(keypad_data, REG_KP_GPIO2, reg >> 8);
+	error |= tca8418_write_byte(keypad_data, REG_KP_GPIO3, reg >> 16);
+
+	/* Enable column debouncing */
+	error |= tca8418_write_byte(keypad_data, REG_DEBOUNCE_DIS1, reg);
+	error |= tca8418_write_byte(keypad_data, REG_DEBOUNCE_DIS2, reg >> 8);
+	error |= tca8418_write_byte(keypad_data, REG_DEBOUNCE_DIS3, reg >> 16);
+
+	return error;
+}
+
+static int tca8418_keypad_probe(struct i2c_client *client,
+					  const struct i2c_device_id *id)
+{
+	struct device *dev = &client->dev;
+	const struct tca8418_keypad_platform_data *pdata =
+						dev_get_platdata(dev);
+	struct tca8418_keypad *keypad_data;
+	struct input_dev *input;
+	const struct matrix_keymap_data *keymap_data = NULL;
+	u32 rows = 0, cols = 0;
+	bool rep = false;
+	bool irq_is_gpio = false;
+	int irq;
+	int error, row_shift, max_keys;
+
+	/* Copy the platform data */
+	if (pdata) {
+		if (!pdata->keymap_data) {
+			dev_err(dev, "no keymap data defined\n");
+			return -EINVAL;
+		}
+		keymap_data = pdata->keymap_data;
+		rows = pdata->rows;
+		cols = pdata->cols;
+		rep  = pdata->rep;
+		irq_is_gpio = pdata->irq_is_gpio;
+	} else {
+		struct device_node *np = dev->of_node;
+		int err;
+
+		err = matrix_keypad_parse_of_params(dev, &rows, &cols);
+		if (err)
+			return err;
+		rep = of_property_read_bool(np, "keypad,autorepeat");
+	}
+
+	if (!rows || rows > TCA8418_MAX_ROWS) {
+		dev_err(dev, "invalid rows\n");
+		return -EINVAL;
+	}
+
+	if (!cols || cols > TCA8418_MAX_COLS) {
+		dev_err(dev, "invalid columns\n");
+		return -EINVAL;
+	}
+
+	/* Check i2c driver capabilities */
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE)) {
+		dev_err(dev, "%s adapter not supported\n",
+			dev_driver_string(&client->adapter->dev));
+		return -ENODEV;
+	}
+
+	row_shift = get_count_order(cols);
+	max_keys = rows << row_shift;
+
+	/* Allocate memory for keypad_data and input device */
+	keypad_data = devm_kzalloc(dev, sizeof(*keypad_data), GFP_KERNEL);
+	if (!keypad_data)
+		return -ENOMEM;
+
+	keypad_data->client = client;
+	keypad_data->row_shift = row_shift;
+
+	/* Initialize the chip or fail if chip isn't present */
+	error = tca8418_configure(keypad_data, rows, cols);
+	if (error < 0)
+		return error;
+
+	/* Configure input device */
+	input = devm_input_allocate_device(dev);
+	if (!input)
+		return -ENOMEM;
+
+	keypad_data->input = input;
+
+	input->name = client->name;
+	input->id.bustype = BUS_I2C;
+	input->id.vendor  = 0x0001;
+	input->id.product = 0x001;
+	input->id.version = 0x0001;
+
+	error = matrix_keypad_build_keymap(keymap_data, NULL, rows, cols,
+					   NULL, input);
+	if (error) {
+		dev_err(dev, "Failed to build keymap\n");
+		return error;
+	}
+
+	if (rep)
+		__set_bit(EV_REP, input->evbit);
+	input_set_capability(input, EV_MSC, MSC_SCAN);
+
+	input_set_drvdata(input, keypad_data);
+
+	irq = client->irq;
+	if (irq_is_gpio)
+		irq = gpio_to_irq(irq);
+
+	error = devm_request_threaded_irq(dev, irq, NULL, tca8418_irq_handler,
+					  IRQF_TRIGGER_FALLING |
+						IRQF_SHARED |
+						IRQF_ONESHOT,
+					  client->name, keypad_data);
+	if (error) {
+		dev_err(dev, "Unable to claim irq %d; error %d\n",
+			client->irq, error);
+		return error;
+	}
+
+	error = input_register_device(input);
+	if (error) {
+		dev_err(dev, "Unable to register input device, error: %d\n",
+			error);
+		return error;
+	}
+
+	return 0;
+}
+
+static const struct i2c_device_id tca8418_id[] = {
+	{ TCA8418_NAME, 8418, },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, tca8418_id);
+
+#ifdef CONFIG_OF
+static const struct of_device_id tca8418_dt_ids[] = {
+	{ .compatible = "ti,tca8418", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, tca8418_dt_ids);
+
+/*
+ * The device tree based i2c loader looks for
+ * "i2c:" + second_component_of(property("compatible"))
+ * and therefore we need an alias to be found.
+ */
+MODULE_ALIAS("i2c:tca8418");
+#endif
+
+static struct i2c_driver tca8418_keypad_driver = {
+	.driver = {
+		.name	= TCA8418_NAME,
+		.of_match_table = of_match_ptr(tca8418_dt_ids),
+	},
+	.probe		= tca8418_keypad_probe,
+	.id_table	= tca8418_id,
+};
+
+static int __init tca8418_keypad_init(void)
+{
+	return i2c_add_driver(&tca8418_keypad_driver);
+}
+subsys_initcall(tca8418_keypad_init);
+
+static void __exit tca8418_keypad_exit(void)
+{
+	i2c_del_driver(&tca8418_keypad_driver);
+}
+module_exit(tca8418_keypad_exit);
+
+MODULE_AUTHOR("Kyle Manna <kyle.manna@fuel7.com>");
+MODULE_DESCRIPTION("Keypad driver for TCA8418");
+MODULE_LICENSE("GPL");