[PATCHv3 0/3] Add support for TCA6416 based Keypad driver.

[PATCHv3 0/3] Add support for TCA6416 based Keypad driver.

[Sriramakrishnan]

AM3517 EVM with APPS board includes keys interfaced to TCA6416 IO expander
User keys are connected as GPIO lines to TCA6416 IO expander. Unlike the
case with generic gpio-keypad driver individual keys do not generate an
interrupt event. Hence we implement a simple keypad driver, that
registers as direct I2C client.

The implementation has been tested on AM3517 EVM with the driver tested
in polling mode.

Version3 is refreshed against the tip of linux-omap and 
file mode issues from the previous version is fixed.

Sriramakrishnan (3):
  TCA6416 keypad : Implement keypad driver for keys interfaced to
    TCA6416
  AM3517: Board hookup for TCA6416 keypad driver.
  AM3517 EVM : Enable TCA6416 keypad.

 arch/arm/configs/am3517_evm_defconfig   |   16 ++-
 arch/arm/mach-omap2/board-am3517evm.c   |   47 ++++-
 drivers/input/keyboard/Kconfig          |   16 ++
 drivers/input/keyboard/Makefile         |    1 +
 drivers/input/keyboard/tca6416-keypad.c |  354 +++++++++++++++++++++++++++++++
 include/linux/tca6416_keypad.h          |   34 +++
 6 files changed, 462 insertions(+), 6 deletions(-)
 create mode 100644 drivers/input/keyboard/tca6416-keypad.c
 create mode 100644 include/linux/tca6416_keypad.h

[PATCHv3 1/3] TCA6416 keypad : Implement keypad driver for keys interfaced to TCA6416

[Sriramakrishnan]

This patch implements a simple Keypad driver that functions
as an I2C client. It handles key press events for keys
connected to TCA6416 I2C based IO expander.

Signed-off-by: Sriramakrishnan <srk@ti.com>
---
 drivers/input/keyboard/Kconfig          |   16 ++
 drivers/input/keyboard/Makefile         |    1 +
 drivers/input/keyboard/tca6416-keypad.c |  354 +++++++++++++++++++++++++++++++
 include/linux/tca6416_keypad.h          |   34 +++
 4 files changed, 405 insertions(+), 0 deletions(-)
 create mode 100644 drivers/input/keyboard/tca6416-keypad.c
 create mode 100644 include/linux/tca6416_keypad.h

diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
index 64c1023..cf7fca9 100644
--- a/drivers/input/keyboard/Kconfig
+++ b/drivers/input/keyboard/Kconfig
@@ -192,6 +192,22 @@ config KEYBOARD_GPIO
 	  To compile this driver as a module, choose M here: the
 	  module will be called gpio_keys.
 
+config KEYBOARD_TCA6416
+	tristate "TCA6416 Keypad Support"
+	depends on I2C
+	help
+	  This driver implements basic keypad functionality
+	  for keys connected through TCA6416 IO expander
+
+	  Say Y here if your device has keys connected to
+	  TCA6416 IO expander. Your board-specific setup logic
+	  must also provide pin-mask details(of which TCA6416 pins
+	  are used for keypad).
+
+	  If enabled the complete TCA6416 device will be managed through
+	  this driver.
+
+
 config KEYBOARD_MATRIX
 	tristate "GPIO driven matrix keypad support"
 	depends on GENERIC_GPIO
diff --git a/drivers/input/keyboard/Makefile b/drivers/input/keyboard/Makefile
index 706c6b5..47e267c 100644
--- a/drivers/input/keyboard/Makefile
+++ b/drivers/input/keyboard/Makefile
@@ -15,6 +15,7 @@ obj-$(CONFIG_KEYBOARD_CORGI)		+= corgikbd.o
 obj-$(CONFIG_KEYBOARD_DAVINCI)		+= davinci_keyscan.o
 obj-$(CONFIG_KEYBOARD_EP93XX)		+= ep93xx_keypad.o
 obj-$(CONFIG_KEYBOARD_GPIO)		+= gpio_keys.o
+obj-$(CONFIG_KEYBOARD_TCA6416)		+= tca6416-keypad.o
 obj-$(CONFIG_KEYBOARD_HIL)		+= hil_kbd.o
 obj-$(CONFIG_KEYBOARD_HIL_OLD)		+= hilkbd.o
 obj-$(CONFIG_KEYBOARD_IMX)		+= imx_keypad.o
diff --git a/drivers/input/keyboard/tca6416-keypad.c b/drivers/input/keyboard/tca6416-keypad.c
new file mode 100644
index 0000000..17df832
--- /dev/null
+++ b/drivers/input/keyboard/tca6416-keypad.c
@@ -0,0 +1,354 @@
+/*
+ * Driver for keys on TCA6416 I2C IO expander
+ *
+ * Copyright (C) 2010 Texas Instruments
+ *
+ * Author : Sriramakrishnan.A.G. <srk@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/gpio.h>
+#include <linux/i2c.h>
+#include <linux/input.h>
+#include <linux/tca6416_keypad.h>
+#include <linux/workqueue.h>
+#include <linux/types.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+
+#define TCA6416_INPUT          0
+#define TCA6416_OUTPUT         1
+#define TCA6416_INVERT         2
+#define TCA6416_DIRECTION      3
+
+static const struct i2c_device_id tca6416_id[] = {
+	{ "tca6416-keys", 16, },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, tca6416_id);
+
+struct tca6416_drv_data {
+	struct input_dev *input;
+	struct tca6416_button data[0];
+};
+
+struct tca6416_keypad_chip {
+	uint16_t reg_output;
+	uint16_t reg_direction;
+	uint16_t reg_input;
+
+	struct i2c_client *client;
+	struct tca6416_drv_data  *drv_data;
+	struct delayed_work dwork;
+	uint16_t pinmask;
+	int irqnum;
+	int use_polling;
+};
+
+static int tca6416_write_reg(struct tca6416_keypad_chip *chip, int reg,
+				uint16_t val)
+{
+	int ret;
+
+	ret = i2c_smbus_write_word_data(chip->client, reg << 1, val);
+
+	if (ret < 0) {
+		dev_err(&chip->client->dev, "failed writing register\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int tca6416_read_reg(struct tca6416_keypad_chip *chip, int reg,
+				uint16_t *val)
+{
+	int ret;
+
+	ret = i2c_smbus_read_word_data(chip->client, reg << 1);
+
+	if (ret < 0) {
+		dev_err(&chip->client->dev, "failed reading register\n");
+		return ret;
+	}
+
+	*val = (uint16_t)ret;
+	return 0;
+}
+
+static irqreturn_t tca6416_keys_isr(int irq, void *dev_id)
+{
+	struct tca6416_keypad_chip *chip =
+		(struct tca6416_keypad_chip *) dev_id;
+
+	disable_irq(irq);
+	schedule_delayed_work(&chip->dwork, 0);
+	return IRQ_HANDLED;
+
+}
+
+static void tca6416_keys_work_func(struct work_struct *workstruct)
+{
+	struct delayed_work *delay_work =
+		container_of(workstruct, struct delayed_work, work);
+	struct tca6416_keypad_chip *chip =
+		container_of(delay_work, struct tca6416_keypad_chip, dwork);
+	struct tca6416_drv_data *ddata = chip->drv_data;
+	uint16_t reg_val, val;
+	int ret, i, pin_index;
+
+	ret = tca6416_read_reg(chip, TCA6416_INPUT, &reg_val);
+	if (ret)
+		return;
+
+	reg_val &= chip->pinmask;
+
+	/* Figure out which lines have changed */
+	val = reg_val ^ (chip->reg_input);
+	chip->reg_input = reg_val;
+
+	for (i = 0, pin_index = 0; i < 16; i++) {
+		if (val & (1 << i)) {
+			struct tca6416_button *button = &ddata->data[pin_index];
+			struct input_dev *input = ddata->input;
+			unsigned int type = button->type ?: EV_KEY;
+			int state = ((reg_val & (1 << i)) ? 1 : 0)
+						^ button->active_low;
+
+			input_event(input, type, button->code, !!state);
+			input_sync(input);
+		}
+
+		if (chip->pinmask & (1 << i))
+			pin_index++;
+	}
+
+	if (chip->use_polling)
+		schedule_delayed_work(&chip->dwork, msecs_to_jiffies(100));
+	else
+		enable_irq(chip->irqnum);
+
+}
+
+
+static int __devinit tca6416_keypad_probe(struct i2c_client *client,
+				   const struct i2c_device_id *id)
+{
+	struct tca6416_keys_platform_data *pdata;
+	struct tca6416_keypad_chip *chip;
+	struct tca6416_drv_data *ddata;
+	struct input_dev *input;
+	int i, ret, pin_index, err;
+	uint16_t reg_val;
+
+	/* Check 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;
+	}
+
+
+	chip = kzalloc(sizeof(struct tca6416_keypad_chip), GFP_KERNEL);
+	if (chip == NULL)
+		return -ENOMEM;
+
+	pdata = client->dev.platform_data;
+	if (pdata == NULL) {
+		dev_dbg(&client->dev, "no platform data\n");
+		ret = -EINVAL;
+		goto fail1;
+	}
+
+	chip->client = client;
+	chip->pinmask = pdata->pinmask;
+
+	/* initialize cached registers from their original values.
+	 * we can't share this chip with another i2c master.
+	 */
+	ret = tca6416_read_reg(chip, TCA6416_OUTPUT, &chip->reg_output);
+	if (ret)
+		goto fail1;
+
+	ret = tca6416_read_reg(chip, TCA6416_DIRECTION, &chip->reg_direction);
+	if (ret)
+		goto fail1;
+
+	/* ensure that keypad pins are set to input */
+	reg_val = chip->reg_direction | chip->pinmask;
+	ret = tca6416_write_reg(chip, TCA6416_DIRECTION, reg_val);
+	if (ret)
+		goto fail1;
+
+	ret = tca6416_read_reg(chip, TCA6416_DIRECTION, &chip->reg_direction);
+	if (ret)
+		goto fail1;
+
+	ret = tca6416_read_reg(chip, TCA6416_INPUT, &chip->reg_input);
+	if (ret)
+		goto fail1;
+
+	i2c_set_clientdata(client, chip);
+
+
+	ddata = kzalloc(sizeof(struct tca6416_drv_data) +
+			pdata->nbuttons * sizeof(struct tca6416_button),
+			GFP_KERNEL);
+	if (!ddata) {
+		ret = -ENOMEM;
+		goto fail1;
+	}
+
+	input = input_allocate_device();
+	if (!input) {
+		dev_dbg(&client->dev, "failed to allocate state\n");
+		ret = -ENOMEM;
+		kfree(ddata);
+		goto fail2;
+	}
+
+	input->phys = "tca6416-keys/input0";
+	input->name = client->name;
+	input->dev.parent = &client->dev;
+
+	input->id.bustype = BUS_HOST;
+	input->id.vendor = 0x0001;
+	input->id.product = 0x0001;
+	input->id.version = 0x0100;
+
+	/* Enable auto repeat feature of Linux input subsystem */
+	if (pdata->rep)
+		__set_bit(EV_REP, input->evbit);
+
+	ddata->input = input;
+
+	for (i = 0; i < pdata->nbuttons; i++) {
+		unsigned int type;
+
+		ddata->data[i] = pdata->buttons[i];
+		type = (pdata->buttons[i].type) ?: EV_KEY;
+		input_set_capability(input, type, (pdata->buttons[i].code));
+	}
+
+	chip->drv_data = ddata;
+	chip->use_polling = pdata->use_polling;
+
+	INIT_DELAYED_WORK(&chip->dwork, tca6416_keys_work_func);
+
+	if (!chip->use_polling) {
+		if (pdata->irq_is_gpio)
+			chip->irqnum = gpio_to_irq(client->irq);
+		else
+			chip->irqnum = client->irq;
+
+		ret = request_irq(chip->irqnum, tca6416_keys_isr,
+				IRQF_SHARED | IRQF_TRIGGER_FALLING ,
+				"tca6416-keypad", chip);
+		if (ret) {
+			dev_dbg(&client->dev,
+				"Unable to claim irq %d; error %d\n",
+				chip->irqnum, ret);
+			goto fail3;
+		}
+		disable_irq(chip->irqnum);
+	}
+
+	ret = input_register_device(input);
+	if (ret) {
+		dev_dbg(&client->dev, "Unable to register input device, "
+			"error: %d\n", ret);
+		goto fail4;
+	}
+
+	/* get current state of buttons */
+
+	ret = tca6416_read_reg(chip, TCA6416_INPUT, &reg_val);
+	if (ret)
+		goto fail5;
+
+	chip->reg_input = reg_val & chip->pinmask;
+
+	for (i = 0, pin_index = 0; i < 16; i++) {
+		if (chip->pinmask & (1 << i)) {
+			struct tca6416_button *button = &ddata->data[pin_index];
+			unsigned int type = button->type ?: EV_KEY;
+			int state = ((reg_val & (1 << i)) ? 1 : 0)
+						^ button->active_low;
+
+			input_event(input, type, button->code, !!state);
+			input_sync(input);
+			pin_index++;
+		}
+	}
+	input_sync(input);
+
+	if (chip->use_polling)
+		schedule_delayed_work(&chip->dwork, msecs_to_jiffies(100));
+	else
+		enable_irq(chip->irqnum);
+
+	return 0;
+
+fail5:
+	input_unregister_device(input);
+fail4:
+	if (!chip->use_polling)
+		free_irq(chip->irqnum, chip);
+fail3:
+	input_free_device(input);
+fail2:
+	kfree(ddata);
+fail1:
+	kfree(chip);
+	return ret;
+}
+
+static int tca6416_keypad_remove(struct i2c_client *client)
+{
+	struct tca6416_keypad_chip *chip = i2c_get_clientdata(client);
+	struct tca6416_drv_data *ddata = chip->drv_data;
+	struct input_dev *input = ddata->input;
+
+	if (!chip->use_polling)
+		free_irq(chip->irqnum, chip);
+	cancel_delayed_work_sync(&chip->dwork);
+	input_unregister_device(input);
+	input_free_device(input);
+	kfree(ddata);
+	kfree(chip);
+	return 0;
+}
+
+
+static struct i2c_driver tca6416_keypad_driver = {
+	.driver = {
+		.name	= "tca6416-keypad",
+	},
+	.probe		= tca6416_keypad_probe,
+	.remove		= tca6416_keypad_remove,
+	.id_table	= tca6416_id,
+};
+
+static int __init tca6416_keypad_init(void)
+{
+	return i2c_add_driver(&tca6416_keypad_driver);
+}
+
+subsys_initcall(tca6416_keypad_init);
+
+static void __exit tca6416_keypad_exit(void)
+{
+	i2c_del_driver(&tca6416_keypad_driver);
+}
+module_exit(tca6416_keypad_exit);
+
+MODULE_AUTHOR("Sriramakrishnan <srk@ti.com>");
+MODULE_DESCRIPTION("Keypad driver over tca6146 IO expander");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/tca6416_keypad.h b/include/linux/tca6416_keypad.h
new file mode 100644
index 0000000..7bd266f
--- /dev/null
+++ b/include/linux/tca6416_keypad.h
@@ -0,0 +1,34 @@
+/*
+ * tca6416 keypad platform support
+ *
+ * Copyright (C) 2010 Texas Instruments
+ *
+ * Author: Sriramakrishnan <srk@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef _TCA6416_KEYS_H
+#define _TCA6416_KEYS_H
+
+#include <linux/types.h>
+
+struct tca6416_button {
+	/* Configuration parameters */
+	int code;		/* input event code (KEY_*, SW_*) */
+	int active_low;
+	int type;		/* input event type (EV_KEY, EV_SW) */
+};
+
+struct tca6416_keys_platform_data {
+	struct tca6416_button *buttons;
+	int nbuttons;
+	unsigned int rep:1;	/* enable input subsystem auto repeat */
+	uint16_t pinmask;
+	uint16_t invert;
+	int irq_is_gpio;
+	int use_polling;	/* use polling if Interrupt is not connected*/
+};
+#endif
-- 
1.6.2.4

[PATCHv3 2/3] AM3517: Board hookup for TCA6416 keypad driver.

[Sriramakrishnan]

Add board specific hookup for TCA6416 keypad driver.

Signed-off-by: Sriramakrishnan <srk@ti.com>
---
 arch/arm/mach-omap2/board-am3517evm.c |   47 +++++++++++++++++++++++++++++---
 1 files changed, 42 insertions(+), 5 deletions(-)

diff --git a/arch/arm/mach-omap2/board-am3517evm.c b/arch/arm/mach-omap2/board-am3517evm.c
index 6ae8805..d50e505 100644
--- a/arch/arm/mach-omap2/board-am3517evm.c
+++ b/arch/arm/mach-omap2/board-am3517evm.c
@@ -20,7 +20,10 @@
 #include <linux/init.h>
 #include <linux/platform_device.h>
 #include <linux/gpio.h>
+#include <linux/i2c.h>
 #include <linux/i2c/pca953x.h>
+#include <linux/input.h>
+#include <linux/tca6416_keypad.h>
 
 #include <mach/hardware.h>
 #include <mach/am35xx.h>
@@ -88,16 +91,50 @@ static struct i2c_board_info __initdata am3517evm_tca6416_info_0[] = {
 };
 
 /* Mounted on UI Card */
-static struct pca953x_platform_data am3517evm_ui_gpio_expander_info_1 = {
+/* IO expander at address 0x20 on UI card will be managed by Keypad driver */
+
+static struct pca953x_platform_data am3517evm_ui_gpio_expander_info_2 = {
 	.gpio_base	= OMAP_MAX_GPIO_LINES + 16,
 };
-static struct pca953x_platform_data am3517evm_ui_gpio_expander_info_2 = {
-	.gpio_base	= OMAP_MAX_GPIO_LINES + 32,
+
+/*Keypad Initialization */
+#define KEYPAD_PIN_MASK                0xFFC0
+
+#define KEYPAD_BUTTON(ev_type, ev_code, act_low) \
+{								\
+	.type		= ev_type,				\
+	.code		= ev_code,				\
+	.active_low	= act_low,				\
+}
+
+#define KEYPAD_BUTTON_LOW(event_code)		\
+	KEYPAD_BUTTON(EV_KEY, event_code, 1)
+
+static struct tca6416_button am3517_gpio_keys[] = {
+	KEYPAD_BUTTON_LOW(KEY_DOWN),
+	KEYPAD_BUTTON_LOW(KEY_UP),
+	KEYPAD_BUTTON_LOW(KEY_MENU),
+	KEYPAD_BUTTON_LOW(KEY_MODE),
+	KEYPAD_BUTTON_LOW(KEY_LEFTSHIFT),
+	KEYPAD_BUTTON_LOW(KEY_REWIND),
+	KEYPAD_BUTTON_LOW(KEY_FORWARD),
+	KEYPAD_BUTTON_LOW(KEY_STOP),
+	KEYPAD_BUTTON_LOW(KEY_PLAY),
+	KEYPAD_BUTTON_LOW(KEY_RECORD),
 };
+
+static struct tca6416_keys_platform_data am3517evm_tca6416_keys_info = {
+	.buttons	= am3517_gpio_keys,
+	.nbuttons	= ARRAY_SIZE(am3517_gpio_keys),
+	.rep		= 1,
+	.use_polling	= 1,
+	.pinmask	= KEYPAD_PIN_MASK,
+};
+
 static struct i2c_board_info __initdata am3517evm_ui_tca6416_info[] = {
 	{
-		I2C_BOARD_INFO("tca6416", 0x20),
-		.platform_data = &am3517evm_ui_gpio_expander_info_1,
+		I2C_BOARD_INFO("tca6416-keys", 0x20),
+		.platform_data = &am3517evm_tca6416_keys_info,
 	},
 	{
 		I2C_BOARD_INFO("tca6416", 0x21),
-- 
1.6.2.4

[PATCHv3 3/3] AM3517 EVM : Enable TCA6416 keypad.

[Sriramakrishnan]

Update kernel configuration for AM3517EVM to include
support for TCA6416 keypad.

Signed-off-by: Sriramakrishnan <srk@ti.com>
---
 arch/arm/configs/am3517_evm_defconfig |   16 +++++++++++++++-
 1 files changed, 15 insertions(+), 1 deletions(-)

diff --git a/arch/arm/configs/am3517_evm_defconfig b/arch/arm/configs/am3517_evm_defconfig
index 66a10b5..93d5fdf 100644
--- a/arch/arm/configs/am3517_evm_defconfig
+++ b/arch/arm/configs/am3517_evm_defconfig
@@ -527,6 +527,7 @@ CONFIG_SCSI_LOWLEVEL=y
 CONFIG_INPUT=y
 # CONFIG_INPUT_FF_MEMLESS is not set
 # CONFIG_INPUT_POLLDEV is not set
+# CONFIG_INPUT_SPARSEKMAP is not set
 
 #
 # Userland interfaces
@@ -539,7 +540,20 @@ CONFIG_INPUT_EVDEV=y
 #
 # Input Device Drivers
 #
-# CONFIG_INPUT_KEYBOARD is not set
+CONFIG_INPUT_KEYBOARD=y
+# CONFIG_KEYBOARD_ADP5588 is not set
+# CONFIG_KEYBOARD_ATKBD is not set
+# CONFIG_QT2160 is not set
+# CONFIG_KEYBOARD_LKKBD is not set
+# CONFIG_KEYBOARD_GPIO is not set
+CONFIG_KEYBOARD_TCA6416=y
+# CONFIG_KEYBOARD_MATRIX is not set
+# CONFIG_KEYBOARD_MAX7359 is not set
+# CONFIG_KEYBOARD_NEWTON is not set
+# CONFIG_KEYBOARD_OPENCORES is not set
+# CONFIG_KEYBOARD_STOWAWAY is not set
+# CONFIG_KEYBOARD_SUNKBD is not set
+# CONFIG_KEYBOARD_XTKBD is not set
 # CONFIG_INPUT_MOUSE is not set
 # CONFIG_INPUT_JOYSTICK is not set
 # CONFIG_INPUT_TABLET is not set
-- 
1.6.2.4

Re: [PATCHv3 1/3] TCA6416 keypad : Implement keypad driver for keys interfaced to TCA6416

[Abraham Arce]

Sriramakrishnan,

Find minor changes proposals...

> +
> +         Say Y here if your device has keys connected to
> +         TCA6416 IO expander. Your board-specific setup logic
> +         must also provide pin-mask details(of which TCA6416 pins
> +         are used for keypad).

space in " details ( "

<snip>

> +       if (chip->use_polling)
> +               schedule_delayed_work(&chip->dwork, msecs_to_jiffies(100));
> +       else
> +               enable_irq(chip->irqnum);
> +
> +}
> +
> +

remove one blank line

> +
> +       /* initialize cached registers from their original values.
> +        * we can't share this chip with another i2c master.
> +        */

should we start our comment section as below?

/*
 * initialize...

<snip>

> +
> +       ret = tca6416_read_reg(chip, TCA6416_INPUT, &chip->reg_input);
> +       if (ret)
> +               goto fail1;
> +
> +       i2c_set_clientdata(client, chip);
> +
> +

remove one blank line

<snip>

> +
> +       if (!chip->use_polling) {
> +               if (pdata->irq_is_gpio)
> +                       chip->irqnum = gpio_to_irq(client->irq);
> +               else
> +                       chip->irqnum = client->irq;
> +
> +               ret = request_irq(chip->irqnum, tca6416_keys_isr,
> +                               IRQF_SHARED | IRQF_TRIGGER_FALLING ,
> +                               "tca6416-keypad", chip);
> +               if (ret) {
> +                       dev_dbg(&client->dev,
> +                               "Unable to claim irq %d; error %d\n",
> +                               chip->irqnum, ret);
> +                       goto fail3;
> +               }
> +               disable_irq(chip->irqnum);

why not using threaded irq?

Best Regards
Abraham
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Re: [PATCHv3 1/3] TCA6416 keypad : Implement keypad driver for keys interfaced to TCA6416

[Dmitry Torokhov]

On Tue, Mar 23, 2010 at 08:40:33PM +0530, Sriramakrishnan wrote:
> This patch implements a simple Keypad driver that functions
> as an I2C client. It handles key press events for keys
> connected to TCA6416 I2C based IO expander.
> 
> Signed-off-by: Sriramakrishnan <srk@ti.com>
> ---
>  drivers/input/keyboard/Kconfig          |   16 ++
>  drivers/input/keyboard/Makefile         |    1 +
>  drivers/input/keyboard/tca6416-keypad.c |  354 +++++++++++++++++++++++++++++++
>  include/linux/tca6416_keypad.h          |   34 +++
>  4 files changed, 405 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/input/keyboard/tca6416-keypad.c
>  create mode 100644 include/linux/tca6416_keypad.h
> 
> diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
> index 64c1023..cf7fca9 100644
> --- a/drivers/input/keyboard/Kconfig
> +++ b/drivers/input/keyboard/Kconfig
> @@ -192,6 +192,22 @@ config KEYBOARD_GPIO
>  	  To compile this driver as a module, choose M here: the
>  	  module will be called gpio_keys.
>  
> +config KEYBOARD_TCA6416
> +	tristate "TCA6416 Keypad Support"
> +	depends on I2C
> +	help
> +	  This driver implements basic keypad functionality
> +	  for keys connected through TCA6416 IO expander
> +
> +	  Say Y here if your device has keys connected to
> +	  TCA6416 IO expander. Your board-specific setup logic
> +	  must also provide pin-mask details(of which TCA6416 pins
> +	  are used for keypad).
> +
> +	  If enabled the complete TCA6416 device will be managed through
> +	  this driver.
> +
> +
>  config KEYBOARD_MATRIX
>  	tristate "GPIO driven matrix keypad support"
>  	depends on GENERIC_GPIO
> diff --git a/drivers/input/keyboard/Makefile b/drivers/input/keyboard/Makefile
> index 706c6b5..47e267c 100644
> --- a/drivers/input/keyboard/Makefile
> +++ b/drivers/input/keyboard/Makefile
> @@ -15,6 +15,7 @@ obj-$(CONFIG_KEYBOARD_CORGI)		+= corgikbd.o
>  obj-$(CONFIG_KEYBOARD_DAVINCI)		+= davinci_keyscan.o
>  obj-$(CONFIG_KEYBOARD_EP93XX)		+= ep93xx_keypad.o
>  obj-$(CONFIG_KEYBOARD_GPIO)		+= gpio_keys.o
> +obj-$(CONFIG_KEYBOARD_TCA6416)		+= tca6416-keypad.o
>  obj-$(CONFIG_KEYBOARD_HIL)		+= hil_kbd.o
>  obj-$(CONFIG_KEYBOARD_HIL_OLD)		+= hilkbd.o
>  obj-$(CONFIG_KEYBOARD_IMX)		+= imx_keypad.o
> diff --git a/drivers/input/keyboard/tca6416-keypad.c b/drivers/input/keyboard/tca6416-keypad.c
> new file mode 100644
> index 0000000..17df832
> --- /dev/null
> +++ b/drivers/input/keyboard/tca6416-keypad.c
> @@ -0,0 +1,354 @@
> +/*
> + * Driver for keys on TCA6416 I2C IO expander
> + *
> + * Copyright (C) 2010 Texas Instruments
> + *
> + * Author : Sriramakrishnan.A.G. <srk@ti.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/gpio.h>
> +#include <linux/i2c.h>
> +#include <linux/input.h>
> +#include <linux/tca6416_keypad.h>
> +#include <linux/workqueue.h>
> +#include <linux/types.h>
> +#include <linux/interrupt.h>
> +#include <linux/delay.h>
> +
> +#define TCA6416_INPUT          0
> +#define TCA6416_OUTPUT         1
> +#define TCA6416_INVERT         2
> +#define TCA6416_DIRECTION      3
> +
> +static const struct i2c_device_id tca6416_id[] = {
> +	{ "tca6416-keys", 16, },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(i2c, tca6416_id);
> +
> +struct tca6416_drv_data {
> +	struct input_dev *input;
> +	struct tca6416_button data[0];
> +};

No need for a separate structure.

> +
> +struct tca6416_keypad_chip {
> +	uint16_t reg_output;
> +	uint16_t reg_direction;
> +	uint16_t reg_input;
> +
> +	struct i2c_client *client;
> +	struct tca6416_drv_data  *drv_data;
> +	struct delayed_work dwork;
> +	uint16_t pinmask;

u16 in kernel is preferred.

> +	int irqnum;
> +	int use_polling;

boolean.

> +};
> +
> +static int tca6416_write_reg(struct tca6416_keypad_chip *chip, int reg,
> +				uint16_t val)
> +{
> +	int ret;
> +
> +	ret = i2c_smbus_write_word_data(chip->client, reg << 1, val);
> +
> +	if (ret < 0) {
> +		dev_err(&chip->client->dev, "failed writing register\n");
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static int tca6416_read_reg(struct tca6416_keypad_chip *chip, int reg,
> +				uint16_t *val)
> +{
> +	int ret;
> +
> +	ret = i2c_smbus_read_word_data(chip->client, reg << 1);
> +
> +	if (ret < 0) {
> +		dev_err(&chip->client->dev, "failed reading register\n");
> +		return ret;
> +	}
> +
> +	*val = (uint16_t)ret;
> +	return 0;
> +}
> +
> +static irqreturn_t tca6416_keys_isr(int irq, void *dev_id)
> +{
> +	struct tca6416_keypad_chip *chip =
> +		(struct tca6416_keypad_chip *) dev_id;
> +
> +	disable_irq(irq);
> +	schedule_delayed_work(&chip->dwork, 0);
> +	return IRQ_HANDLED;
> +
> +}
> +
> +static void tca6416_keys_work_func(struct work_struct *workstruct)
> +{
> +	struct delayed_work *delay_work =
> +		container_of(workstruct, struct delayed_work, work);
> +	struct tca6416_keypad_chip *chip =
> +		container_of(delay_work, struct tca6416_keypad_chip, dwork);
> +	struct tca6416_drv_data *ddata = chip->drv_data;
> +	uint16_t reg_val, val;
> +	int ret, i, pin_index;
> +
> +	ret = tca6416_read_reg(chip, TCA6416_INPUT, &reg_val);
> +	if (ret)
> +		return;
> +
> +	reg_val &= chip->pinmask;
> +
> +	/* Figure out which lines have changed */
> +	val = reg_val ^ (chip->reg_input);
> +	chip->reg_input = reg_val;
> +
> +	for (i = 0, pin_index = 0; i < 16; i++) {
> +		if (val & (1 << i)) {
> +			struct tca6416_button *button = &ddata->data[pin_index];
> +			struct input_dev *input = ddata->input;
> +			unsigned int type = button->type ?: EV_KEY;
> +			int state = ((reg_val & (1 << i)) ? 1 : 0)
> +						^ button->active_low;
> +
> +			input_event(input, type, button->code, !!state);
> +			input_sync(input);
> +		}
> +
> +		if (chip->pinmask & (1 << i))
> +			pin_index++;
> +	}
> +
> +	if (chip->use_polling)
> +		schedule_delayed_work(&chip->dwork, msecs_to_jiffies(100));
> +	else
> +		enable_irq(chip->irqnum);
> +
> +}
> +
> +
> +static int __devinit tca6416_keypad_probe(struct i2c_client *client,
> +				   const struct i2c_device_id *id)
> +{
> +	struct tca6416_keys_platform_data *pdata;
> +	struct tca6416_keypad_chip *chip;
> +	struct tca6416_drv_data *ddata;
> +	struct input_dev *input;
> +	int i, ret, pin_index, err;
> +	uint16_t reg_val;
> +
> +	/* Check 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;
> +	}
> +
> +
> +	chip = kzalloc(sizeof(struct tca6416_keypad_chip), GFP_KERNEL);
> +	if (chip == NULL)
> +		return -ENOMEM;
> +
> +	pdata = client->dev.platform_data;
> +	if (pdata == NULL) {
> +		dev_dbg(&client->dev, "no platform data\n");
> +		ret = -EINVAL;
> +		goto fail1;
> +	}
> +
> +	chip->client = client;
> +	chip->pinmask = pdata->pinmask;
> +
> +	/* initialize cached registers from their original values.
> +	 * we can't share this chip with another i2c master.
> +	 */
> +	ret = tca6416_read_reg(chip, TCA6416_OUTPUT, &chip->reg_output);
> +	if (ret)
> +		goto fail1;
> +
> +	ret = tca6416_read_reg(chip, TCA6416_DIRECTION, &chip->reg_direction);
> +	if (ret)
> +		goto fail1;
> +
> +	/* ensure that keypad pins are set to input */
> +	reg_val = chip->reg_direction | chip->pinmask;
> +	ret = tca6416_write_reg(chip, TCA6416_DIRECTION, reg_val);
> +	if (ret)
> +		goto fail1;
> +
> +	ret = tca6416_read_reg(chip, TCA6416_DIRECTION, &chip->reg_direction);
> +	if (ret)
> +		goto fail1;
> +
> +	ret = tca6416_read_reg(chip, TCA6416_INPUT, &chip->reg_input);
> +	if (ret)
> +		goto fail1;
> +
> +	i2c_set_clientdata(client, chip);
> +
> +
> +	ddata = kzalloc(sizeof(struct tca6416_drv_data) +
> +			pdata->nbuttons * sizeof(struct tca6416_button),
> +			GFP_KERNEL);
> +	if (!ddata) {
> +		ret = -ENOMEM;
> +		goto fail1;
> +	}
> +
> +	input = input_allocate_device();
> +	if (!input) {
> +		dev_dbg(&client->dev, "failed to allocate state\n");
> +		ret = -ENOMEM;
> +		kfree(ddata);
> +		goto fail2;
> +	}
> +
> +	input->phys = "tca6416-keys/input0";
> +	input->name = client->name;
> +	input->dev.parent = &client->dev;
> +
> +	input->id.bustype = BUS_HOST;
> +	input->id.vendor = 0x0001;
> +	input->id.product = 0x0001;
> +	input->id.version = 0x0100;
> +
> +	/* Enable auto repeat feature of Linux input subsystem */
> +	if (pdata->rep)
> +		__set_bit(EV_REP, input->evbit);
> +
> +	ddata->input = input;
> +
> +	for (i = 0; i < pdata->nbuttons; i++) {
> +		unsigned int type;
> +
> +		ddata->data[i] = pdata->buttons[i];
> +		type = (pdata->buttons[i].type) ?: EV_KEY;
> +		input_set_capability(input, type, (pdata->buttons[i].code));
> +	}
> +
> +	chip->drv_data = ddata;
> +	chip->use_polling = pdata->use_polling;
> +
> +	INIT_DELAYED_WORK(&chip->dwork, tca6416_keys_work_func);
> +
> +	if (!chip->use_polling) {
> +		if (pdata->irq_is_gpio)
> +			chip->irqnum = gpio_to_irq(client->irq);
> +		else
> +			chip->irqnum = client->irq;
> +
> +		ret = request_irq(chip->irqnum, tca6416_keys_isr,
> +				IRQF_SHARED | IRQF_TRIGGER_FALLING ,
> +				"tca6416-keypad", chip);
> +		if (ret) {
> +			dev_dbg(&client->dev,
> +				"Unable to claim irq %d; error %d\n",
> +				chip->irqnum, ret);
> +			goto fail3;
> +		}
> +		disable_irq(chip->irqnum);

If I unload the driver without anyone opening the device IRQ will be
left dosabled forever.

> +	}
> +
> +	ret = input_register_device(input);
> +	if (ret) {
> +		dev_dbg(&client->dev, "Unable to register input device, "
> +			"error: %d\n", ret);
> +		goto fail4;
> +	}
> +
> +	/* get current state of buttons */
> +
> +	ret = tca6416_read_reg(chip, TCA6416_INPUT, &reg_val);
> +	if (ret)
> +		goto fail5;
> +
> +	chip->reg_input = reg_val & chip->pinmask;
> +
> +	for (i = 0, pin_index = 0; i < 16; i++) {
> +		if (chip->pinmask & (1 << i)) {
> +			struct tca6416_button *button = &ddata->data[pin_index];
> +			unsigned int type = button->type ?: EV_KEY;
> +			int state = ((reg_val & (1 << i)) ? 1 : 0)
> +						^ button->active_low;
> +
> +			input_event(input, type, button->code, !!state);
> +			input_sync(input);
> +			pin_index++;
> +		}
> +	}

Duplicated code.

> +	input_sync(input);
> +
> +	if (chip->use_polling)
> +		schedule_delayed_work(&chip->dwork, msecs_to_jiffies(100));
> +	else
> +		enable_irq(chip->irqnum);
> +
> +	return 0;
> +
> +fail5:
> +	input_unregister_device(input);
> +fail4:
> +	if (!chip->use_polling)
> +		free_irq(chip->irqnum, chip);
> +fail3:
> +	input_free_device(input);
> +fail2:
> +	kfree(ddata);
> +fail1:
> +	kfree(chip);
> +	return ret;
> +}
> +
> +static int tca6416_keypad_remove(struct i2c_client *client)

__devexit

> +{
> +	struct tca6416_keypad_chip *chip = i2c_get_clientdata(client);
> +	struct tca6416_drv_data *ddata = chip->drv_data;
> +	struct input_dev *input = ddata->input;
> +
> +	if (!chip->use_polling)
> +		free_irq(chip->irqnum, chip);
> +	cancel_delayed_work_sync(&chip->dwork);

This may leave IRQ disabled if you happen to really cancel the work.

> +	input_unregister_device(input);
> +	input_free_device(input);

input_free_device should not be called after unregister.

> +	kfree(ddata);
> +	kfree(chip);
> +	return 0;
> +}
> +
> +
> +static struct i2c_driver tca6416_keypad_driver = {
> +	.driver = {
> +		.name	= "tca6416-keypad",
> +	},
> +	.probe		= tca6416_keypad_probe,
> +	.remove		= tca6416_keypad_remove,

__devexit_p

> +	.id_table	= tca6416_id,
> +};
> +
> +static int __init tca6416_keypad_init(void)
> +{
> +	return i2c_add_driver(&tca6416_keypad_driver);
> +}
> +
> +subsys_initcall(tca6416_keypad_init);
> +
> +static void __exit tca6416_keypad_exit(void)
> +{
> +	i2c_del_driver(&tca6416_keypad_driver);
> +}
> +module_exit(tca6416_keypad_exit);
> +
> +MODULE_AUTHOR("Sriramakrishnan <srk@ti.com>");
> +MODULE_DESCRIPTION("Keypad driver over tca6146 IO expander");
> +MODULE_LICENSE("GPL");
> diff --git a/include/linux/tca6416_keypad.h b/include/linux/tca6416_keypad.h
> new file mode 100644
> index 0000000..7bd266f
> --- /dev/null
> +++ b/include/linux/tca6416_keypad.h
> @@ -0,0 +1,34 @@
> +/*
> + * tca6416 keypad platform support
> + *
> + * Copyright (C) 2010 Texas Instruments
> + *
> + * Author: Sriramakrishnan <srk@ti.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#ifndef _TCA6416_KEYS_H
> +#define _TCA6416_KEYS_H
> +
> +#include <linux/types.h>
> +
> +struct tca6416_button {
> +	/* Configuration parameters */
> +	int code;		/* input event code (KEY_*, SW_*) */
> +	int active_low;

bool?

> +	int type;		/* input event type (EV_KEY, EV_SW) */

Wierd ordeting, make type, code, polarity.

> +};
> +
> +struct tca6416_keys_platform_data {
> +	struct tca6416_button *buttons;
> +	int nbuttons;
> +	unsigned int rep:1;	/* enable input subsystem auto repeat */

bool.

> +	uint16_t pinmask;
> +	uint16_t invert;

Does not seep to be used.

> +	int irq_is_gpio;

bool.

> +	int use_polling;	/* use polling if Interrupt is not connected*/

bool.

> +};
> +#endif

Does the driver still work if you aplly the patch below on top?

Thanks.

-- 
Dmitry

Input: tca6416 - misc fixes

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
---

 drivers/input/keyboard/tca6416-keypad.c |  327 +++++++++++++++----------------
 1 files changed, 160 insertions(+), 167 deletions(-)


diff --git a/drivers/input/keyboard/tca6416-keypad.c b/drivers/input/keyboard/tca6416-keypad.c
index 17df832..0943af3 100644
--- a/drivers/input/keyboard/tca6416-keypad.c
+++ b/drivers/input/keyboard/tca6416-keypad.c
@@ -10,16 +10,17 @@
  * published by the Free Software Foundation.
  */
 
+#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/tca6416_keypad.h>
-#include <linux/workqueue.h>
-#include <linux/types.h>
-#include <linux/interrupt.h>
-#include <linux/delay.h>
 
 #define TCA6416_INPUT          0
 #define TCA6416_OUTPUT         1
@@ -43,79 +44,63 @@ struct tca6416_keypad_chip {
 	uint16_t reg_input;
 
 	struct i2c_client *client;
-	struct tca6416_drv_data  *drv_data;
+	struct input_dev *input;
 	struct delayed_work dwork;
-	uint16_t pinmask;
+	u16 pinmask;
 	int irqnum;
-	int use_polling;
+	bool use_polling;
+	struct tca6416_button buttons[0];
 };
 
-static int tca6416_write_reg(struct tca6416_keypad_chip *chip, int reg,
-				uint16_t val)
+static int tca6416_write_reg(struct tca6416_keypad_chip *chip, int reg, u16 val)
 {
-	int ret;
-
-	ret = i2c_smbus_write_word_data(chip->client, reg << 1, val);
-
-	if (ret < 0) {
-		dev_err(&chip->client->dev, "failed writing register\n");
-		return ret;
+	int error;
+
+	error = i2c_smbus_write_word_data(chip->client, reg << 1, val);
+	if (error < 0) {
+		dev_err(&chip->client->dev,
+			"%s failed, reg: %d, val: %d, error: %d\n",
+			__func__, reg, val, error);
+		return error;
 	}
 
 	return 0;
 }
 
-static int tca6416_read_reg(struct tca6416_keypad_chip *chip, int reg,
-				uint16_t *val)
+static int tca6416_read_reg(struct tca6416_keypad_chip *chip, int reg, u16 *val)
 {
-	int ret;
-
-	ret = i2c_smbus_read_word_data(chip->client, reg << 1);
+	int retval;
 
-	if (ret < 0) {
-		dev_err(&chip->client->dev, "failed reading register\n");
-		return ret;
+	retval = i2c_smbus_read_word_data(chip->client, reg << 1);
+	if (retval < 0) {
+		dev_err(&chip->client->dev, "%s failed, reg: %d, error: %d\n",
+			__func__, reg, retval);
+		return retval;
 	}
 
-	*val = (uint16_t)ret;
+	*val = (u16)retval;
 	return 0;
 }
 
-static irqreturn_t tca6416_keys_isr(int irq, void *dev_id)
-{
-	struct tca6416_keypad_chip *chip =
-		(struct tca6416_keypad_chip *) dev_id;
-
-	disable_irq(irq);
-	schedule_delayed_work(&chip->dwork, 0);
-	return IRQ_HANDLED;
-
-}
-
-static void tca6416_keys_work_func(struct work_struct *workstruct)
+static void tca6416_keys_scan(struct tca6416_keypad_chip *chip)
 {
-	struct delayed_work *delay_work =
-		container_of(workstruct, struct delayed_work, work);
-	struct tca6416_keypad_chip *chip =
-		container_of(delay_work, struct tca6416_keypad_chip, dwork);
-	struct tca6416_drv_data *ddata = chip->drv_data;
-	uint16_t reg_val, val;
-	int ret, i, pin_index;
+	struct input_dev *input = chip->input;
+	u16 reg_val, val;
+	int error, i, pin_index;
 
-	ret = tca6416_read_reg(chip, TCA6416_INPUT, &reg_val);
-	if (ret)
+	error = tca6416_read_reg(chip, TCA6416_INPUT, &reg_val);
+	if (error)
 		return;
 
 	reg_val &= chip->pinmask;
 
 	/* Figure out which lines have changed */
-	val = reg_val ^ (chip->reg_input);
+	val = reg_val ^ chip->reg_input;
 	chip->reg_input = reg_val;
 
 	for (i = 0, pin_index = 0; i < 16; i++) {
 		if (val & (1 << i)) {
-			struct tca6416_button *button = &ddata->data[pin_index];
-			struct input_dev *input = ddata->input;
+			struct tca6416_button *button = &chip->buttons[pin_index];
 			unsigned int type = button->type ?: EV_KEY;
 			int state = ((reg_val & (1 << i)) ? 1 : 0)
 						^ button->active_low;
@@ -127,97 +112,128 @@ static void tca6416_keys_work_func(struct work_struct *workstruct)
 		if (chip->pinmask & (1 << i))
 			pin_index++;
 	}
+}
+
+/*
+ * This is threaded IRQ handler and this can (and will) sleep.
+ */
+static irqreturn_t tca6416_keys_isr(int irq, void *dev_id)
+{
+	struct tca6416_keypad_chip *chip = dev_id;
+
+	tca6416_keys_scan(chip);
+
+	return IRQ_HANDLED;
+}
+
+static void tca6416_keys_work_func(struct work_struct *work)
+{
+	struct tca6416_keypad_chip *chip =
+		container_of(work, struct tca6416_keypad_chip, dwork.work);
+
+	tca6416_keys_scan(chip);
+	schedule_delayed_work(&chip->dwork, msecs_to_jiffies(100));
+}
+
+static int tca6416_keys_open(struct input_dev *dev)
+{
+	struct tca6416_keypad_chip *chip = input_get_drvdata(dev);
+
+	/* Get initial device state in case it has switches */
+	tca6416_keys_scan(chip);
 
 	if (chip->use_polling)
 		schedule_delayed_work(&chip->dwork, msecs_to_jiffies(100));
 	else
 		enable_irq(chip->irqnum);
 
+	return 0;
+}
+
+static void tca6416_keys_close(struct input_dev *dev)
+{
+	struct tca6416_keypad_chip *chip = input_get_drvdata(dev);
+
+	if (chip->use_polling)
+		cancel_delayed_work_sync(&chip->dwork);
+	else
+		free_irq(chip->irqnum, chip);
 }
 
+static int __devinit tca6416_setup_registers(struct tca6416_keypad_chip *chip)
+{
+	int error;
+
+	error = tca6416_read_reg(chip, TCA6416_OUTPUT, &chip->reg_output);
+	if (error)
+		return error;
+
+	error = tca6416_read_reg(chip, TCA6416_DIRECTION, &chip->reg_direction);
+	if (error)
+		return error;
+
+	/* ensure that keypad pins are set to input */
+	error = tca6416_write_reg(chip, TCA6416_DIRECTION,
+				  chip->reg_direction | chip->pinmask);
+	if (error)
+		return error;
+
+	error = tca6416_read_reg(chip, TCA6416_DIRECTION, &chip->reg_direction);
+	if (error)
+		return error;
+
+	error = tca6416_read_reg(chip, TCA6416_INPUT, &chip->reg_input);
+	if (error)
+		return error;
+
+	return 0;
+}
 
 static int __devinit tca6416_keypad_probe(struct i2c_client *client,
 				   const struct i2c_device_id *id)
 {
 	struct tca6416_keys_platform_data *pdata;
 	struct tca6416_keypad_chip *chip;
-	struct tca6416_drv_data *ddata;
 	struct input_dev *input;
-	int i, ret, pin_index, err;
-	uint16_t reg_val;
+	int error;
+	int i;
 
 	/* Check functionality */
-	err = i2c_check_functionality(client->adapter,
-			I2C_FUNC_SMBUS_BYTE);
-	if (!err) {
+	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;
 	}
 
-
-	chip = kzalloc(sizeof(struct tca6416_keypad_chip), GFP_KERNEL);
-	if (chip == NULL)
-		return -ENOMEM;
-
 	pdata = client->dev.platform_data;
-	if (pdata == NULL) {
+	if (!pdata) {
 		dev_dbg(&client->dev, "no platform data\n");
-		ret = -EINVAL;
+		return -EINVAL;
+	}
+
+	chip = kzalloc(sizeof(struct tca6416_keypad_chip) +
+		       pdata->nbuttons * sizeof(struct tca6416_button),
+		       GFP_KERNEL);
+	input = input_allocate_device();
+	if (!chip || !input) {
+		error = -ENOMEM;
 		goto fail1;
 	}
 
 	chip->client = client;
+	chip->input = input;
 	chip->pinmask = pdata->pinmask;
+	chip->use_polling = pdata->use_polling;
 
-	/* initialize cached registers from their original values.
-	 * we can't share this chip with another i2c master.
-	 */
-	ret = tca6416_read_reg(chip, TCA6416_OUTPUT, &chip->reg_output);
-	if (ret)
-		goto fail1;
-
-	ret = tca6416_read_reg(chip, TCA6416_DIRECTION, &chip->reg_direction);
-	if (ret)
-		goto fail1;
-
-	/* ensure that keypad pins are set to input */
-	reg_val = chip->reg_direction | chip->pinmask;
-	ret = tca6416_write_reg(chip, TCA6416_DIRECTION, reg_val);
-	if (ret)
-		goto fail1;
-
-	ret = tca6416_read_reg(chip, TCA6416_DIRECTION, &chip->reg_direction);
-	if (ret)
-		goto fail1;
-
-	ret = tca6416_read_reg(chip, TCA6416_INPUT, &chip->reg_input);
-	if (ret)
-		goto fail1;
-
-	i2c_set_clientdata(client, chip);
-
-
-	ddata = kzalloc(sizeof(struct tca6416_drv_data) +
-			pdata->nbuttons * sizeof(struct tca6416_button),
-			GFP_KERNEL);
-	if (!ddata) {
-		ret = -ENOMEM;
-		goto fail1;
-	}
-
-	input = input_allocate_device();
-	if (!input) {
-		dev_dbg(&client->dev, "failed to allocate state\n");
-		ret = -ENOMEM;
-		kfree(ddata);
-		goto fail2;
-	}
+	INIT_DELAYED_WORK(&chip->dwork, tca6416_keys_work_func);
 
 	input->phys = "tca6416-keys/input0";
 	input->name = client->name;
 	input->dev.parent = &client->dev;
 
+	input->open = tca6416_keys_open;
+	input->close = tca6416_keys_close;
+
 	input->id.bustype = BUS_HOST;
 	input->id.vendor = 0x0001;
 	input->id.product = 0x0001;
@@ -227,20 +243,23 @@ static int __devinit tca6416_keypad_probe(struct i2c_client *client,
 	if (pdata->rep)
 		__set_bit(EV_REP, input->evbit);
 
-	ddata->input = input;
-
 	for (i = 0; i < pdata->nbuttons; i++) {
 		unsigned int type;
 
-		ddata->data[i] = pdata->buttons[i];
+		chip->buttons[i] = pdata->buttons[i];
 		type = (pdata->buttons[i].type) ?: EV_KEY;
-		input_set_capability(input, type, (pdata->buttons[i].code));
+		input_set_capability(input, type, pdata->buttons[i].code);
 	}
 
-	chip->drv_data = ddata;
-	chip->use_polling = pdata->use_polling;
+	input_set_drvdata(input, chip);
 
-	INIT_DELAYED_WORK(&chip->dwork, tca6416_keys_work_func);
+	/*
+	 * Initialize cached registers from their original values.
+	 * we can't share this chip with another i2c master.
+	 */
+	error = tca6416_setup_registers(chip);
+	if (error)
+		goto fail1;
 
 	if (!chip->use_polling) {
 		if (pdata->irq_is_gpio)
@@ -248,81 +267,55 @@ static int __devinit tca6416_keypad_probe(struct i2c_client *client,
 		else
 			chip->irqnum = client->irq;
 
-		ret = request_irq(chip->irqnum, tca6416_keys_isr,
-				IRQF_SHARED | IRQF_TRIGGER_FALLING ,
-				"tca6416-keypad", chip);
-		if (ret) {
+		error = request_threaded_irq(chip->irqnum, NULL,
+					     tca6416_keys_isr,
+					     IRQF_TRIGGER_FALLING,
+					     "tca6416-keypad", chip);
+		if (error) {
 			dev_dbg(&client->dev,
 				"Unable to claim irq %d; error %d\n",
-				chip->irqnum, ret);
-			goto fail3;
+				chip->irqnum, error);
+			goto fail1;
 		}
 		disable_irq(chip->irqnum);
 	}
 
-	ret = input_register_device(input);
-	if (ret) {
-		dev_dbg(&client->dev, "Unable to register input device, "
-			"error: %d\n", ret);
-		goto fail4;
-	}
-
-	/* get current state of buttons */
-
-	ret = tca6416_read_reg(chip, TCA6416_INPUT, &reg_val);
-	if (ret)
-		goto fail5;
-
-	chip->reg_input = reg_val & chip->pinmask;
-
-	for (i = 0, pin_index = 0; i < 16; i++) {
-		if (chip->pinmask & (1 << i)) {
-			struct tca6416_button *button = &ddata->data[pin_index];
-			unsigned int type = button->type ?: EV_KEY;
-			int state = ((reg_val & (1 << i)) ? 1 : 0)
-						^ button->active_low;
-
-			input_event(input, type, button->code, !!state);
-			input_sync(input);
-			pin_index++;
-		}
+	error = input_register_device(input);
+	if (error) {
+		dev_dbg(&client->dev,
+			"Unable to register input device, error: %d\n", error);
+		goto fail2;
 	}
-	input_sync(input);
 
-	if (chip->use_polling)
-		schedule_delayed_work(&chip->dwork, msecs_to_jiffies(100));
-	else
-		enable_irq(chip->irqnum);
+	i2c_set_clientdata(client, chip);
 
 	return 0;
 
-fail5:
-	input_unregister_device(input);
-fail4:
-	if (!chip->use_polling)
-		free_irq(chip->irqnum, chip);
-fail3:
-	input_free_device(input);
 fail2:
-	kfree(ddata);
+	if (!chip->use_polling) {
+		free_irq(chip->irqnum, chip);
+		enable_irq(chip->irqnum);
+	}
 fail1:
+	input_free_device(input);
 	kfree(chip);
-	return ret;
+	return error;
 }
 
-static int tca6416_keypad_remove(struct i2c_client *client)
+static int __devexit tca6416_keypad_remove(struct i2c_client *client)
 {
 	struct tca6416_keypad_chip *chip = i2c_get_clientdata(client);
-	struct tca6416_drv_data *ddata = chip->drv_data;
-	struct input_dev *input = ddata->input;
 
-	if (!chip->use_polling)
+	if (!chip->use_polling) {
 		free_irq(chip->irqnum, chip);
-	cancel_delayed_work_sync(&chip->dwork);
-	input_unregister_device(input);
-	input_free_device(input);
-	kfree(ddata);
+		enable_irq(chip->irqnum);
+	}
+
+	input_unregister_device(chip->input);
 	kfree(chip);
+
+	i2c_set_clientdata(client, NULL);
+
 	return 0;
 }
 
@@ -332,7 +325,7 @@ static struct i2c_driver tca6416_keypad_driver = {
 		.name	= "tca6416-keypad",
 	},
 	.probe		= tca6416_keypad_probe,
-	.remove		= tca6416_keypad_remove,
+	.remove		= __devexit_p(tca6416_keypad_remove),
 	.id_table	= tca6416_id,
 };
 

RE: [PATCHv3 1/3] TCA6416 keypad : Implement keypad driver for keys interfaced to TCA6416

[Govindarajan, Sriramakrishnan]

> -----Original Message-----
> From: Dmitry Torokhov [mailto:dmitry.torokhov@gmail.com]
> Sent: Friday, April 16, 2010 10:55 AM
> To: Govindarajan, Sriramakrishnan
> Cc: linux-omap@vger.kernel.org; linux-input@vger.kernel.org
> Subject: Re: [PATCHv3 1/3] TCA6416 keypad : Implement keypad driver for
> keys interfaced to TCA6416
> 
> On Tue, Mar 23, 2010 at 08:40:33PM +0530, Sriramakrishnan wrote:
> > This patch implements a simple Keypad driver that functions
> > as an I2C client. It handles key press events for keys
> > connected to TCA6416 I2C based IO expander.
> >
> > Signed-off-by: Sriramakrishnan <srk@ti.com>
> > ---
> >  drivers/input/keyboard/Kconfig          |   16 ++
> >  drivers/input/keyboard/Makefile         |    1 +
> >  drivers/input/keyboard/tca6416-keypad.c |  354
> +++++++++++++++++++++++++++++++
> >  include/linux/tca6416_keypad.h          |   34 +++
> >  4 files changed, 405 insertions(+), 0 deletions(-)
> >  create mode 100644 drivers/input/keyboard/tca6416-keypad.c
> >  create mode 100644 include/linux/tca6416_keypad.h
----snip----
Does the driver still work if you aplly the patch below on top?
[Sriram] Dmitry, I was able to test with the patch below(again scope restricted to Polling mode) and it works but with following minor changes. Please review.
> 
> Thanks.
> 
> --
> Dmitry
> 
> Input: tca6416 - misc fixes
> 
> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
> ---
> 
>  drivers/input/keyboard/tca6416-keypad.c |  327 +++++++++++++++-----------
> -----
>  1 files changed, 160 insertions(+), 167 deletions(-)
> 
> 
> diff --git a/drivers/input/keyboard/tca6416-keypad.c
> b/drivers/input/keyboard/tca6416-keypad.c
> index 17df832..0943af3 100644
> --- a/drivers/input/keyboard/tca6416-keypad.c
> +++ b/drivers/input/keyboard/tca6416-keypad.c
> @@ -10,16 +10,17 @@
>   * published by the Free Software Foundation.
>   */
---snip---

> +static int tca6416_keys_open(struct input_dev *dev)
> +{
> +	struct tca6416_keypad_chip *chip = input_get_drvdata(dev);
> +
> +	/* Get initial device state in case it has switches */
> +	tca6416_keys_scan(chip);
> 
>  	if (chip->use_polling)
>  		schedule_delayed_work(&chip->dwork, msecs_to_jiffies(100));
>  	else
>  		enable_irq(chip->irqnum);
> 
> +	return 0;
> +}
> +
> +static void tca6416_keys_close(struct input_dev *dev)
> +{
> +	struct tca6416_keypad_chip *chip = input_get_drvdata(dev);
> +
> +	if (chip->use_polling)
> +		cancel_delayed_work_sync(&chip->dwork);
> +	else
> +		free_irq(chip->irqnum, chip);
[Sriram] replaced free_irq() with disable_irq() instead. This should take care of multiple (concurrent) opens.

>  }
> 
> +static int __devinit tca6416_setup_registers(struct tca6416_keypad_chip
> *chip)
> +{
> +	int error;
> +
> +	error = tca6416_read_reg(chip, TCA6416_OUTPUT, &chip->reg_output);
> +	if (error)
> +		return error;
> +
> +	error = tca6416_read_reg(chip, TCA6416_DIRECTION, &chip-
> >reg_direction);
> +	if (error)
> +		return error;
> +
> +	/* ensure that keypad pins are set to input */
> +	error = tca6416_write_reg(chip, TCA6416_DIRECTION,
> +				  chip->reg_direction | chip->pinmask);
> +	if (error)
> +		return error;
> +
> +	error = tca6416_read_reg(chip, TCA6416_DIRECTION, &chip-
> >reg_direction);
> +	if (error)
> +		return error;
> +
> +	error = tca6416_read_reg(chip, TCA6416_INPUT, &chip->reg_input);
> +	if (error)
> +		return error;

[Sriram] reg_input cached value needs to be masked with pinmask - otherwise on device open the driver reports continuous stream of key_down(repeat) events until a key is pressed.

> +	return 0;
> +}
> 
[Sriram] Dmitry, once you have reviewed the changes, should I re-post the patch series with your patch added to the series?

Regards
Sriram

Re: [PATCHv3 1/3] TCA6416 keypad : Implement keypad driver for keys interfaced to TCA6416

[Dmitry Torokhov]

On Fri, Apr 30, 2010 at 07:49:20PM +0530, Govindarajan, Sriramakrishnan
wrote:
> > 
> [Sriram] Dmitry, once you have reviewed the changes, should I re-post
> the patch series with your patch added to the series?
> 

Sriram,

Thank you for reviewing my changes.

I folded my changes into your original patch and will commit it to the
next bramch of my tree. The board-specific changes will have to go
thotugh maintainer of the arch in question.

-- 
Dmitry

RE: [PATCHv3 0/3] Add support for TCA6416 based Keypad driver.

[Govindarajan, Sriramakrishnan]

> -----Original Message-----
> From: Govindarajan, Sriramakrishnan
> Sent: Tuesday, March 23, 2010 8:41 PM
> To: linux-omap@vger.kernel.org; linux-input@vger.kernel.org
> Cc: Govindarajan, Sriramakrishnan
> Subject: [PATCHv3 0/3] Add support for TCA6416 based Keypad driver.
> 
> AM3517 EVM with APPS board includes keys interfaced to TCA6416 IO expander
> User keys are connected as GPIO lines to TCA6416 IO expander. Unlike the
> case with generic gpio-keypad driver individual keys do not generate an
> interrupt event. Hence we implement a simple keypad driver, that
> registers as direct I2C client.
> 
> The implementation has been tested on AM3517 EVM with the driver tested
> in polling mode.
> 
> Version3 is refreshed against the tip of linux-omap and
> file mode issues from the previous version is fixed.
> 
> Sriramakrishnan (3):
>   TCA6416 keypad : Implement keypad driver for keys interfaced to
>     TCA6416
>   AM3517: Board hookup for TCA6416 keypad driver.
>   AM3517 EVM : Enable TCA6416 keypad.
> 
>  arch/arm/configs/am3517_evm_defconfig   |   16 ++-
>  arch/arm/mach-omap2/board-am3517evm.c   |   47 ++++-
>  drivers/input/keyboard/Kconfig          |   16 ++
>  drivers/input/keyboard/Makefile         |    1 +
>  drivers/input/keyboard/tca6416-keypad.c |  354
> +++++++++++++++++++++++++++++++
>  include/linux/tca6416_keypad.h          |   34 +++
>  6 files changed, 462 insertions(+), 6 deletions(-)
>  create mode 100644 drivers/input/keyboard/tca6416-keypad.c
>  create mode 100644 include/linux/tca6416_keypad.h

[Sriram] All,
Any feedback on this updated patch series?
Thanks
Sriram