davinci: dm365evm_keys driver

Add basic driver for the MSP430 on the DM 365 EVM; it's used
only to report commands from an IR remote.  (This assumes the
same remote used with other DaVinci EVM boards.)
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

arch/arm/mach-davinci/board-dm365-evm.c

@@ -178,6 +178,9 @@ static struct at24_platform_data eeprom_info = {
 };
 
 static struct i2c_board_info i2c_info[] = {
+	{
+		I2C_BOARD_INFO("dm365evm_keys", 0x25),
+	},
 	{
 		I2C_BOARD_INFO("24c256", 0x50),
 		.platform_data	= &eeprom_info,

drivers/input/misc/Kconfig

@@ -269,4 +269,14 @@ config INPUT_DM355EVM
 
 	  To compile this driver as a module, choose M here: the
 	  module will be called dm355evm_keys.
+
+config INPUT_DM365EVM
+	tristate "TI DaVinci DM365 EVM IR Remote"
+	depends on MACH_DAVINCI_DM365_EVM
+	help
+	  Supports the IR remote used with the DM365 EVM board.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called dm365evm_keys.
+
 endif

drivers/input/misc/Makefile

@@ -11,6 +11,7 @@ obj-$(CONFIG_INPUT_ATLAS_BTNS)		+= atlas_btns.o
 obj-$(CONFIG_INPUT_CM109)		+= cm109.o
 obj-$(CONFIG_INPUT_COBALT_BTNS)		+= cobalt_btns.o
 obj-$(CONFIG_INPUT_DM355EVM)		+= dm355evm_keys.o
+obj-$(CONFIG_INPUT_DM365EVM)		+= dm365evm_keys.o
 obj-$(CONFIG_HP_SDC_RTC)		+= hp_sdc_rtc.o
 obj-$(CONFIG_INPUT_IXP4XX_BEEPER)	+= ixp4xx-beeper.o
 obj-$(CONFIG_INPUT_KEYSPAN_REMOTE)	+= keyspan_remote.o

drivers/input/misc/dm365evm_keys.c

+/*
+ * dm365evm_keys.c - support IR remote on DM365 EVM board
+ *
+ * Copyright (c) 2009 by David Brownell
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/input.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/gpio.h>
+
+
+/*
+ * The MSP430 firmware on the DM365 EVM monitors an IR receptor used for
+ * the remote control.  When any key is pressed, or its autorepeat kicks
+ * in, an event is sent.  This driver read those events from the small
+ * event queue and reports them.
+ *
+ * Compared to the DM355 EVM:  the MSP firmware does *only* IR.  So this
+ * driver is simpler, and doesn't even need to use the MFD model.
+ *
+ * Note that physically there can only be one of these devices.
+ *
+ * This driver was tested with firmware revision 0xA1 (beta board).
+ */
+struct dm365evm_keys {
+	struct input_dev	*input;
+	struct i2c_client	*i2c;
+};
+
+#define DM365EVM_MSP_FIRMREV		0
+#define DM365EVM_MSP_INPUT_LOW		1
+#define DM365EVM_MSP_INPUT_HIGH		2
+#define DM365EVM_MSP_INPUT_COUNT	3
+#define DM365EVM_MSP_0x43		4
+
+#define MSP430_GPIO			0
+
+/* These initial keycodes can be remapped by dm365evm_setkeycode(). */
+static struct {
+	u16	event;
+	u16	keycode;
+} dm365evm_keys[] = {
+
+	/*
+	 * IR buttons ... codes assigned to match the universal remote
+	 * provided with the EVM (Philips PM4S) using DVD code 0020.
+	 *
+	 * These event codes match firmware documentation, but other
+	 * remote controls could easily send more RC5-encoded events.
+	 * The PM4S manual was used in several cases to help select
+	 * a keycode reflecting the intended usage.
+	 *
+	 * RC5 codes are 14 bits, with two start bits (0x3 prefix)
+	 * and a toggle bit (masked out below).
+	 */
+	{ 0x300c, KEY_POWER, },		/* NOTE: docs omit this */
+	{ 0x3000, KEY_NUMERIC_0, },
+	{ 0x3001, KEY_NUMERIC_1, },
+	{ 0x3002, KEY_NUMERIC_2, },
+	{ 0x3003, KEY_NUMERIC_3, },
+	{ 0x3004, KEY_NUMERIC_4, },
+	{ 0x3005, KEY_NUMERIC_5, },
+	{ 0x3006, KEY_NUMERIC_6, },
+	{ 0x3007, KEY_NUMERIC_7, },
+	{ 0x3008, KEY_NUMERIC_8, },
+	{ 0x3009, KEY_NUMERIC_9, },
+	{ 0x3022, KEY_ENTER, },
+	{ 0x30ec, KEY_MODE, },		/* "tv/vcr/..." */
+	{ 0x300f, KEY_SELECT, },	/* "info" */
+	{ 0x3020, KEY_CHANNELUP, },	/* "up" */
+	{ 0x302e, KEY_MENU, },		/* "in/out" */
+	{ 0x3011, KEY_VOLUMEDOWN, },	/* "left" */
+	{ 0x300d, KEY_MUTE, },		/* "ok" */
+	{ 0x3010, KEY_VOLUMEUP, },	/* "right" */
+	{ 0x301e, KEY_SUBTITLE, },	/* "cc" */
+	{ 0x3021, KEY_CHANNELDOWN, },	/* "down" */
+	{ 0x3022, KEY_PREVIOUS, },
+	{ 0x3026, KEY_SLEEP, },
+	{ 0x3172, KEY_REWIND, },
+	{ 0x3175, KEY_PLAY, },
+	{ 0x3174, KEY_FASTFORWARD, },
+	{ 0x3177, KEY_RECORD, },
+	{ 0x3176, KEY_STOP, },
+	{ 0x3169, KEY_PAUSE, },
+
+	/* NOTE:  SW22, a pushbutton next to the IR sensor, is also
+	 * wired to the MSP430 but is currently ignored; some other
+	 * I/O pins are likewise wired but ignored.
+	 */
+};
+
+static irqreturn_t dm365evm_keys_irq(int irq, void *_keys)
+{
+	struct dm365evm_keys	*keys = _keys;
+
+	/* For simplicity we ignore INPUT_COUNT and just read
+	 * events until the GPIO stops signaling data ready.
+	 */
+	while (gpio_get_value(MSP430_GPIO) == 0) {
+		static u16	last_event;
+		u16		event;
+		int		keycode;
+		int		i;
+
+		/* Read low, then high bytes; reading the high byte
+		 * removes an entry from the input buffer.
+		 */
+		event = i2c_smbus_read_word_data(keys->i2c,
+					DM365EVM_MSP_INPUT_LOW);
+		if (event < 0) {
+			dev_dbg(&keys->i2c->dev, "input err %d\n", event);
+			break;
+		}
+		event = event;
+
+		/* Press and release a button:  two events, same code.
+		 * Press and hold (autorepeat), then release: N events
+		 * (N > 2), same code.  For RC5 buttons the toggle bits
+		 * distinguish (for example) "1-autorepeat" from "1 1";
+		 * but PCB buttons don't support that bit.
+		 *
+		 * So we must synthesize release events.  We do that by
+		 * mapping events to a press/release event pair; then
+		 * to avoid adding extra events, skip the second event
+		 * of each pair.
+		 */
+		if (event == last_event) {
+			last_event = 0;
+			continue;
+		}
+		last_event = event;
+
+		/* ignore the RC5 toggle bit */
+		event &= ~0x0800;
+
+		/* find the key, or leave it as unknown */
+		keycode = KEY_UNKNOWN;
+		for (i = 0; i < ARRAY_SIZE(dm365evm_keys); i++) {
+			if (dm365evm_keys[i].event != event)
+				continue;
+			keycode = dm365evm_keys[i].keycode;
+			break;
+		}
+		dev_dbg(&keys->i2c->dev,
+			"input event 0x%04x--> keycode %d\n",
+			event, keycode);
+
+		/* report press + release */
+		input_report_key(keys->input, keycode, 1);
+		input_sync(keys->input);
+		input_report_key(keys->input, keycode, 0);
+		input_sync(keys->input);
+	}
+	return IRQ_HANDLED;
+}
+
+/*
+ * Since we talk to the MSP using I2C, we need to delegate all real
+ * IRQ handling work to some task context.  We'll use an IRQ thread.
+ */
+static irqreturn_t dm365evm_keys_hardirq(int irq, void *_keys)
+{
+	return IRQ_WAKE_THREAD;
+}
+
+static int dm365evm_setkeycode(struct input_dev *dev, int index, int keycode)
+{
+	u16		old_keycode;
+	unsigned	i;
+
+	if (((unsigned)index) >= ARRAY_SIZE(dm365evm_keys))
+		return -EINVAL;
+
+	old_keycode = dm365evm_keys[index].keycode;
+	dm365evm_keys[index].keycode = keycode;
+	set_bit(keycode, dev->keybit);
+
+	for (i = 0; i < ARRAY_SIZE(dm365evm_keys); i++) {
+		if (dm365evm_keys[index].keycode == old_keycode)
+			goto done;
+	}
+	clear_bit(old_keycode, dev->keybit);
+done:
+	return 0;
+}
+
+static int dm365evm_getkeycode(struct input_dev *dev, int index, int *keycode)
+{
+	if (((unsigned)index) >= ARRAY_SIZE(dm365evm_keys))
+		return -EINVAL;
+
+	return dm365evm_keys[index].keycode;
+}
+
+/*----------------------------------------------------------------------*/
+
+static int __devinit
+dm365evm_keys_probe(struct i2c_client *i2c, const struct i2c_device_id *id)
+{
+	struct dm365evm_keys	*keys;
+	struct input_dev	*input;
+	int			status;
+	int			i;
+
+	status = gpio_request(MSP430_GPIO, id->name);
+	if (status < 0)
+		return status;
+
+	status = gpio_direction_input(MSP430_GPIO);
+	if (status < 0) {
+		gpio_free(MSP430_GPIO);
+		return status;
+	}
+
+	/* allocate instance struct and input dev */
+	keys = kzalloc(sizeof *keys, GFP_KERNEL);
+	input = input_allocate_device();
+	if (!keys || !input) {
+		status = -ENOMEM;
+		goto fail1;
+	}
+
+	keys->i2c = i2c;
+	keys->input = input;
+
+	input_set_drvdata(input, keys);
+
+	input->name = "DM365 EVM Controls";
+	input->phys = "dm365evm/input0";
+	input->dev.parent = &i2c->dev;
+
+	input->id.bustype = BUS_I2C;
+	input->id.product = 0x0365;
+	input->id.version = i2c_smbus_read_byte_data(i2c,
+					DM365EVM_MSP_FIRMREV);
+
+	input->evbit[0] = BIT(EV_KEY);
+	for (i = 0; i < ARRAY_SIZE(dm365evm_keys); i++)
+		__set_bit(dm365evm_keys[i].keycode, input->keybit);
+
+	input->setkeycode = dm365evm_setkeycode;
+	input->getkeycode = dm365evm_getkeycode;
+
+	/* FIXME:  flush the event queue */
+
+	status = request_threaded_irq(gpio_to_irq(MSP430_GPIO),
+			dm365evm_keys_hardirq, dm365evm_keys_irq,
+			IRQF_TRIGGER_FALLING,
+			id->name, keys);
+	if (status < 0)
+		goto fail1;
+
+	/* register */
+	status = input_register_device(input);
+	if (status < 0)
+		goto fail2;
+
+	i2c_set_clientdata(i2c, keys);
+
+	return 0;
+
+fail2:
+	free_irq(gpio_to_irq(MSP430_GPIO), keys);
+fail1:
+	input_free_device(input);
+	kfree(keys);
+	gpio_free(MSP430_GPIO);
+	dev_err(&i2c->dev, "can't register, err %d\n", status);
+
+	return status;
+}
+
+static int __devexit dm365evm_keys_remove(struct i2c_client *i2c)
+{
+	struct dm365evm_keys	*keys = i2c_get_clientdata(i2c);
+
+	free_irq(gpio_to_irq(MSP430_GPIO), keys);
+	input_unregister_device(keys->input);
+	kfree(keys);
+
+	gpio_free(MSP430_GPIO);
+
+	return 0;
+}
+
+/* REVISIT:  add suspend/resume when DaVinci supports it.  The IRQ should
+ * be able to wake up the system.  When device_may_wakeup(&i2c->dev), call
+ * enable_irq_wake() on suspend, and disable_irq_wake() on resume.
+ */
+
+static const struct i2c_device_id ids[] = {
+	{ .name = "dm365evm_keys", },
+	{ },
+};
+MODULE_DEVICE_TABLE(i2c, ids);
+
+static struct i2c_driver dm365evm_keys_driver = {
+	.driver.name	= "dm365evm_keys",
+	.id_table	= ids,
+	.probe		= dm365evm_keys_probe,
+	.remove		= __devexit_p(dm365evm_keys_remove),
+};
+
+static int __init dm365evm_keys_init(void)
+{
+	return i2c_add_driver(&dm365evm_keys_driver);
+}
+module_init(dm365evm_keys_init);
+
+static void __exit dm365evm_keys_exit(void)
+{
+	i2c_del_driver(&dm365evm_keys_driver);
+}
+module_exit(dm365evm_keys_exit);
+
+MODULE_LICENSE("GPL");