[patch 2.6.28-rc6-davinci1 5/6] dm355evm input driver

[David Brownell <david-b@pacbell.net>]

From: David Brownell <dbrownell@users.sourceforge.net>

Simple input driver support for the events reported by the
MSP430 firmware on the DM355 EVM.  Verified using the remote
included with the kit; docs weren't quite right.  Some of
the keycode selections might need improvement; I'm hoping
I implemented the remapping support right, so there's at
least a runtime workaround.

Keys on the remote seem to repeat undesirably.  Someone might
want to see what's up with that, and fix it; it might just
be an issue of tracking RC5 state and using the toggle.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
---
Depends on the patch for the parent MFD driver, and won't work
without the patch making GPIO IRQs work on dm355.

NOTE:  not suitable for mainline until the dm355evm board support
(and parent MFD driver) is in the merge queue.

 drivers/input/keyboard/Kconfig         |    8 
 drivers/input/keyboard/Makefile        |    1 
 drivers/input/keyboard/dm355evm_keys.c |  303 +++++++++++++++++++++++++++++++
 3 files changed, 312 insertions(+)

--- a/drivers/input/keyboard/Kconfig
+++ b/drivers/input/keyboard/Kconfig
@@ -356,4 +356,12 @@ config KEYBOARD_SH_KEYSC
 
 	  To compile this driver as a module, choose M here: the
 	  module will be called sh_keysc.
+
+config KEYBOARD_DM355EVM
+	tristate "TI DaVinci DM355 EVM Keypad and IR Remote"
+	depends on MFD_DM355EVM_MSP
+	help
+	  Supports the pushbuttons and IR remote used with
+	  the DM355 EVM board.
+
 endif
--- a/drivers/input/keyboard/Makefile
+++ b/drivers/input/keyboard/Makefile
@@ -31,3 +31,4 @@ obj-$(CONFIG_KEYBOARD_HP7XX)		+= jornada
 obj-$(CONFIG_KEYBOARD_MAPLE)		+= maple_keyb.o
 obj-$(CONFIG_KEYBOARD_BFIN)		+= bf54x-keys.o
 obj-$(CONFIG_KEYBOARD_SH_KEYSC)		+= sh_keysc.o
+obj-$(CONFIG_KEYBOARD_DM355EVM)		+= dm355evm_keys.o
--- /dev/null
+++ b/drivers/input/keyboard/dm355evm_keys.c
@@ -0,0 +1,303 @@
+/*
+ * dm355evm_keys.c - support buttons and IR remote on DM355 EVM board
+ *
+ * Copyright (c) 2008 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/platform_device.h>
+#include <linux/interrupt.h>
+
+#include <linux/i2c/dm355evm_msp.h>
+
+
+/*
+ * The MSP430 firmware on the DM355 EVM monitors on-board pushbuttons
+ * and 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 (32 event) queue and reports them.
+ *
+ * Because we communicate with the MSP430 using I2C, and all I2C calls
+ * in Linux sleep, we need to cons up a kind of threaded IRQ handler
+ * using a work_struct.  The IRQ is active low, but we use it through
+ * the GPIO controller so we can trigger on falling edges.
+ *
+ * This driver was tested with firmware revision A4.
+ */
+struct dm355evm_keys {
+	struct work_struct	work;
+	struct input_dev	*input;
+	struct platform_device	*pdev;
+	int			irq;
+};
+
+#include <linux/gpio.h>
+
+static irqreturn_t dm355evm_keys_irq(int irq, void *_keys)
+{
+	struct dm355evm_keys	*keys = _keys;
+
+	schedule_work(&keys->work);
+	return IRQ_HANDLED;
+}
+
+/* These initial keycodes can be remapped by dm355evm_setkeycode(). */
+static struct {
+	u16	event;
+	u16	keycode;
+} dm355evm_keys[] = {
+
+	/*
+	 * Pushbuttons on the EVM board ... note that the labels for these
+	 * are SW10/SW11/etc on the PC board.  The left/right orientation
+	 * comes only from the firmware's documentation, and presumes the
+	 * power connector is immediately in front of you and the IR sensor
+	 * is to the right.  (That is, rotate the board counter-clockwise
+	 * by 90 degrees from the SW10/etc and "DM355 EVM" labels.)
+	 */
+	{ 0x00d8, KEY_OK, },		/* SW12 */
+	{ 0x00b8, KEY_UP, },		/* SW13 */
+	{ 0x00e8, KEY_DOWN, },		/* SW11 */
+	{ 0x0078, KEY_LEFT, },		/* SW14 */
+	{ 0x00f0, KEY_RIGHT, },		/* SW10 */
+
+	/*
+	 * 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, },	/* NOTE: docs wrongly say 0x30ca */
+	{ 0x3175, KEY_PLAY, },
+	{ 0x3174, KEY_FASTFORWARD, },
+	{ 0x3177, KEY_RECORD, },
+	{ 0x3176, KEY_STOP, },
+	{ 0x3169, KEY_PAUSE, },
+};
+
+static void dm355evm_keys_work(struct work_struct *work)
+{
+	struct dm355evm_keys	*keys;
+	int			status;
+
+	keys = container_of(work, struct dm355evm_keys, work);
+
+	/* For simplicity we ignore INPUT_COUNT and just read
+	 * events until we get the "queue empty" indicator.
+	 * Reading INPUT_LOW decrements the count.
+	 */
+	for (;;) {
+		u16		event;
+		int		keycode;
+		int		i;
+
+		status = dm355evm_msp_read(DM355EVM_MSP_INPUT_HIGH);
+		if (status < 0) {
+			dev_dbg(&keys->pdev->dev, "input high err %d\n",
+					status);
+			break;
+		}
+		event = status << 8;
+
+		status = dm355evm_msp_read(DM355EVM_MSP_INPUT_LOW);
+		if (status < 0) {
+			dev_dbg(&keys->pdev->dev, "input low err %d\n",
+					status);
+			break;
+		}
+		event |= status;
+		if (event == 0xdead)
+			break;
+
+		/* ignore the RC5 toggle bit */
+		event &= ~0x0800;
+
+		/* find the key, or leave it as unknown */
+		keycode = KEY_UNKNOWN;
+		for (i = 0; i < ARRAY_SIZE(dm355evm_keys); i++) {
+			if (dm355evm_keys[i].event != event)
+				continue;
+			keycode = dm355evm_keys[i].keycode;
+			break;
+		}
+		dev_dbg(&keys->pdev->dev,
+			"input event 0x%04x--> keycode %d\n",
+			event, keycode);
+
+		/* Report press + release ... we can't tell if
+		 * this is an autorepeat, and we need to guess
+		 * about the release.
+		 */
+		input_report_key(keys->input, keycode, 1);
+		input_report_key(keys->input, keycode, 0);
+	}
+	input_sync(keys->input);
+}
+
+static int dm355evm_setkeycode(struct input_dev *dev, int index, int keycode)
+{
+	if (index >= ARRAY_SIZE(dm355evm_keys))
+		return -EINVAL;
+
+	dm355evm_keys[index].keycode = keycode;
+	return 0;
+}
+
+static int dm355evm_getkeycode(struct input_dev *dev, int index, int *keycode)
+{
+	if (index >= ARRAY_SIZE(dm355evm_keys))
+		return -EINVAL;
+
+	return dm355evm_keys[index].keycode;
+}
+
+/*----------------------------------------------------------------------*/
+
+static int __devinit dm355evm_keys_probe(struct platform_device *pdev)
+{
+	struct dm355evm_keys	*keys;
+	int			status = -ENOMEM;
+	struct input_dev	*input;
+	int			i;
+
+	/* allocate instance struct */
+	keys = kzalloc(sizeof *keys, GFP_KERNEL);
+	if (!keys)
+		goto fail0;
+	platform_set_drvdata(pdev, keys);
+	keys->pdev = pdev;
+
+	/* ... and input dev ... */
+	input = input_allocate_device();
+	if (!input)
+		goto fail0;
+	keys->input = input;
+	input_set_drvdata(input, keys);
+
+	input->name = "DM355 EVM Controls";
+	input->phys = "dm355evm/input0";
+	input->dev.parent = &pdev->dev;
+
+	input->id.bustype = BUS_I2C;
+	input->id.product = 0x0355;
+	input->id.version = dm355evm_msp_read(DM355EVM_MSP_FIRMREV);
+
+	input->evbit[0] = BIT(EV_KEY);
+	for (i = 0; i < ARRAY_SIZE(dm355evm_keys); i++)
+		set_bit(dm355evm_keys[i].keycode, input->keybit);
+
+	input->keycodemax = ARRAY_SIZE(dm355evm_keys);
+	input->keycodesize = sizeof(dm355evm_keys[0]);
+	input->keycode = dm355evm_keys;
+	input->setkeycode = dm355evm_setkeycode;
+	input->getkeycode = dm355evm_getkeycode;
+
+	/* set up "threaded IRQ handler" */
+	status = platform_get_irq(pdev, 0);
+	if (status < 0)
+		goto fail1;
+	keys->irq = status;
+	INIT_WORK(&keys->work, dm355evm_keys_work);
+
+	/* REVISIT:  flush the event queue? */
+
+	/* register */
+	status = input_register_device(input);
+	if (status < 0)
+		goto fail1;
+
+	/* start reporting events */
+	status = request_irq(keys->irq, dm355evm_keys_irq,
+			IRQF_TRIGGER_FALLING,
+			dev_name(&pdev->dev), keys);
+	if (status < 0) {
+		input_unregister_device(input);
+		goto fail1;
+	}
+
+	return 0;
+
+fail1:
+	input_free_device(input);
+fail0:
+	kfree(keys);
+	dev_err(&pdev->dev, "can't register, err %d\n", status);
+	return status;
+}
+
+static int __devexit dm355evm_keys_remove(struct platform_device *pdev)
+{
+	struct dm355evm_keys	*keys = platform_get_drvdata(pdev);
+
+	free_irq(keys->irq, keys);
+	input_unregister_device(keys->input);
+	kfree(keys);
+	return 0;
+}
+
+/* REVISIT:  add suspend/resume when DaVinci supports it.  The IRQ should
+ * be able to wake up the system.  When device_may_wakeup(&pdev->dev), call
+ * enable_irq_wake() on suspend, and disable_irq_wake() on resume.
+ */
+
+/*
+ * I2C is used to talk to the MSP430, but this platform device is
+ * exposed by an MFD driver that manages I2C communications.
+ */
+static struct platform_driver dm355evm_keys_driver = {
+	.probe		= dm355evm_keys_probe,
+	.remove		= __devexit_p(dm355evm_keys_remove),
+	.driver		= {
+		.owner	= THIS_MODULE,
+		.name	= "dm355evm_keys",
+	},
+};
+
+static int __init dm355evm_keys_init(void)
+{
+	return platform_driver_register(&dm355evm_keys_driver);
+}
+module_init(dm355evm_keys_init);
+
+static void __exit dm355evm_keys_exit(void)
+{
+	platform_driver_unregister(&dm355evm_keys_driver);
+}
+module_exit(dm355evm_keys_exit);
+
+MODULE_LICENSE("GPL");