Input: tca8418_keypad - initial driver release

This driver has been tested with hardware and works as expected.  To use
it add the platform data as appropriate and register it with the
corresponding I2C bus.

Signed-off-by: Kyle Manna <kyle.manna@fuel7.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

1 files changed, 430 insertions, 0 deletions

diff --git a/drivers/input/keyboard/tca8418_keypad.c b/drivers/input/keyboard/tca8418_keypad.c
new file mode 100644
index 000000000000..958ec107bfbc
--- /dev/null
+++ b/drivers/input/keyboard/tca8418_keypad.c
@@ -0,0 +1,430 @@
+/*
+ * 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>
+
+/* 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
+
+
+static const struct i2c_device_id tca8418_id[] = {
+	{ TCA8418_NAME, 8418, },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, tca8418_id);
+
+struct tca8418_keypad {
+	unsigned int rows;
+	unsigned int cols;
+	unsigned int keypad_mask; /* Mask for keypad col/rol regs */
+	unsigned int irq;
+	unsigned int row_shift;
+
+	struct i2c_client *client;
+	struct input_dev *input;
+
+	/* Flexible array member, must be at end of struct */
+	unsigned short keymap[];
+};
+
+/*
+ * 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)
+{
+	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(keypad_data->input, EV_MSC, MSC_SCAN, code);
+		input_report_key(keypad_data->input,
+				keypad_data->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(keypad_data->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");
+		goto exit;
+	}
+
+	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);
+
+exit:
+	/* 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 __devinit tca8418_configure(struct tca8418_keypad *keypad_data)
+{
+	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 << keypad_data->rows);
+	reg += (~(~0 << keypad_data->cols)) << 8;
+	keypad_data->keypad_mask = reg;
+
+	/* 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 __devinit tca8418_keypad_probe(struct i2c_client *client,
+					  const struct i2c_device_id *id)
+{
+	const struct tca8418_keypad_platform_data *pdata =
+						client->dev.platform_data;
+	struct tca8418_keypad *keypad_data;
+	struct input_dev *input;
+	int error, row_shift, max_keys;
+
+	/* Copy the platform data */
+	if (!pdata) {
+		dev_dbg(&client->dev, "no platform data\n");
+		return -EINVAL;
+	}
+
+	if (!pdata->keymap_data) {
+		dev_err(&client->dev, "no keymap data defined\n");
+		return -EINVAL;
+	}
+
+	if (!pdata->rows || pdata->rows > TCA8418_MAX_ROWS) {
+		dev_err(&client->dev, "invalid rows\n");
+		return -EINVAL;
+	}
+
+	if (!pdata->cols || pdata->cols > TCA8418_MAX_COLS) {
+		dev_err(&client->dev, "invalid columns\n");
+		return -EINVAL;
+	}
+
+	/* Check i2c driver capabilities */
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE)) {
+		dev_err(&client->dev, "%s adapter not supported\n",
+			dev_driver_string(&client->adapter->dev));
+		return -ENODEV;
+	}
+
+	row_shift = get_count_order(pdata->cols);
+	max_keys = pdata->rows << row_shift;
+
+	/* Allocate memory for keypad_data, keymap and input device */
+	keypad_data = kzalloc(sizeof(*keypad_data) +
+			max_keys * sizeof(keypad_data->keymap[0]), GFP_KERNEL);
+	if (!keypad_data)
+		return -ENOMEM;
+
+	keypad_data->rows = pdata->rows;
+	keypad_data->cols = pdata->cols;
+	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);
+	if (error < 0)
+		goto fail1;
+
+	/* Configure input device */
+	input = input_allocate_device();
+	if (!input) {
+		error = -ENOMEM;
+		goto fail1;
+	}
+	keypad_data->input = input;
+
+	input->name = client->name;
+	input->dev.parent = &client->dev;
+
+	input->id.bustype = BUS_I2C;
+	input->id.vendor  = 0x0001;
+	input->id.product = 0x001;
+	input->id.version = 0x0001;
+
+	input->keycode     = keypad_data->keymap;
+	input->keycodesize = sizeof(keypad_data->keymap[0]);
+	input->keycodemax  = max_keys;
+
+	__set_bit(EV_KEY, input->evbit);
+	if (pdata->rep)
+		__set_bit(EV_REP, input->evbit);
+
+	input_set_capability(input, EV_MSC, MSC_SCAN);
+
+	input_set_drvdata(input, keypad_data);
+
+	matrix_keypad_build_keymap(pdata->keymap_data, row_shift,
+			input->keycode, input->keybit);
+
+	if (pdata->irq_is_gpio)
+		client->irq = gpio_to_irq(client->irq);
+
+	error = request_threaded_irq(client->irq, NULL, tca8418_irq_handler,
+				     IRQF_TRIGGER_FALLING,
+				     client->name, keypad_data);
+	if (error) {
+		dev_dbg(&client->dev,
+			"Unable to claim irq %d; error %d\n",
+			client->irq, error);
+		goto fail2;
+	}
+
+	error = input_register_device(input);
+	if (error) {
+		dev_dbg(&client->dev,
+			"Unable to register input device, error: %d\n", error);
+		goto fail3;
+	}
+
+	i2c_set_clientdata(client, keypad_data);
+	return 0;
+
+fail3:
+	free_irq(client->irq, keypad_data);
+fail2:
+	input_free_device(input);
+fail1:
+	kfree(keypad_data);
+	return error;
+}
+
+static int __devexit tca8418_keypad_remove(struct i2c_client *client)
+{
+	struct tca8418_keypad *keypad_data = i2c_get_clientdata(client);
+
+	free_irq(keypad_data->client->irq, keypad_data);
+
+	input_unregister_device(keypad_data->input);
+
+	kfree(keypad_data);
+
+	return 0;
+}
+
+
+static struct i2c_driver tca8418_keypad_driver = {
+	.driver = {
+		.name	= TCA8418_NAME,
+		.owner	= THIS_MODULE,
+	},
+	.probe		= tca8418_keypad_probe,
+	.remove		= __devexit_p(tca8418_keypad_remove),
+	.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");