da850-evm: add baseboard GPIO expander buttons, switches and LEDs

This patch adds a pca953x platform device for the tca6416 found on the evm
baseboard. The tca6416 is a GPIO expander, also found on the UI board at a
separate I2C address. The pins of the baseboard IO expander are connected to
software reset, deep sleep enable, test points, a push button, DIP switches and
LEDs.

Add support for the push button, DIP switches and LEDs and test points (as
free GPIOs). The reset and deep sleep enable connections are reserved by the
setup routine so that userspace can't toggle those lines.

The existing tca6416-keypad driver was not employed because there was no
apararent way to register the LEDs connected to gpio's on the tca6416 while
simultaneously registering the tca6416-keypad instance.

Signed-off-by: Ben Gardiner <bengardiner@nanometrics.ca>
Reviewed-by: Chris Cordahi <christophercordahi@nanometrics.ca>
CC: Govindarajan, Sriramakrishnan <srk@ti.com>
Reviewed-by: Sekhar Nori <nsekhar@ti.com>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
CC: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

arch/arm/mach-davinci/board-da850-evm.c

@@ -430,6 +430,182 @@ static int da850_evm_ui_expander_teardown(struct i2c_client *client,
 	return 0;
 }
 
+/* assign the baseboard expander's GPIOs after the UI board's */
+#define DA850_UI_EXPANDER_N_GPIOS ARRAY_SIZE(da850_evm_ui_exp)
+#define DA850_BB_EXPANDER_GPIO_BASE (DAVINCI_N_GPIO + DA850_UI_EXPANDER_N_GPIOS)
+
+enum da850_evm_bb_exp_pins {
+	DA850_EVM_BB_EXP_DEEP_SLEEP_EN = 0,
+	DA850_EVM_BB_EXP_SW_RST,
+	DA850_EVM_BB_EXP_TP_23,
+	DA850_EVM_BB_EXP_TP_22,
+	DA850_EVM_BB_EXP_TP_21,
+	DA850_EVM_BB_EXP_USER_PB1,
+	DA850_EVM_BB_EXP_USER_LED2,
+	DA850_EVM_BB_EXP_USER_LED1,
+	DA850_EVM_BB_EXP_USER_SW1,
+	DA850_EVM_BB_EXP_USER_SW2,
+	DA850_EVM_BB_EXP_USER_SW3,
+	DA850_EVM_BB_EXP_USER_SW4,
+	DA850_EVM_BB_EXP_USER_SW5,
+	DA850_EVM_BB_EXP_USER_SW6,
+	DA850_EVM_BB_EXP_USER_SW7,
+	DA850_EVM_BB_EXP_USER_SW8
+};
+
+static const char const *da850_evm_bb_exp[] = {
+	[DA850_EVM_BB_EXP_DEEP_SLEEP_EN]	= "deep_sleep_en",
+	[DA850_EVM_BB_EXP_SW_RST]		= "sw_rst",
+	[DA850_EVM_BB_EXP_TP_23]		= "tp_23",
+	[DA850_EVM_BB_EXP_TP_22]		= "tp_22",
+	[DA850_EVM_BB_EXP_TP_21]		= "tp_21",
+	[DA850_EVM_BB_EXP_USER_PB1]		= "user_pb1",
+	[DA850_EVM_BB_EXP_USER_LED2]		= "user_led2",
+	[DA850_EVM_BB_EXP_USER_LED1]		= "user_led1",
+	[DA850_EVM_BB_EXP_USER_SW1]		= "user_sw1",
+	[DA850_EVM_BB_EXP_USER_SW2]		= "user_sw2",
+	[DA850_EVM_BB_EXP_USER_SW3]		= "user_sw3",
+	[DA850_EVM_BB_EXP_USER_SW4]		= "user_sw4",
+	[DA850_EVM_BB_EXP_USER_SW5]		= "user_sw5",
+	[DA850_EVM_BB_EXP_USER_SW6]		= "user_sw6",
+	[DA850_EVM_BB_EXP_USER_SW7]		= "user_sw7",
+	[DA850_EVM_BB_EXP_USER_SW8]		= "user_sw8",
+};
+
+#define DA850_N_BB_USER_SW	8
+
+static struct gpio_keys_button da850_evm_bb_keys[] = {
+	[0] = {
+		.type			= EV_KEY,
+		.active_low		= 1,
+		.wakeup			= 0,
+		.debounce_interval	= DA850_KEYS_DEBOUNCE_MS,
+		.code			= KEY_PROG1,
+		.desc			= NULL, /* assigned at runtime */
+		.gpio			= -1, /* assigned at runtime */
+	},
+	[1 ... DA850_N_BB_USER_SW] = {
+		.type			= EV_SW,
+		.active_low		= 1,
+		.wakeup			= 0,
+		.debounce_interval	= DA850_KEYS_DEBOUNCE_MS,
+		.code			= -1, /* assigned at runtime */
+		.desc			= NULL, /* assigned at runtime */
+		.gpio			= -1, /* assigned at runtime */
+	},
+};
+
+static struct gpio_keys_platform_data da850_evm_bb_keys_pdata = {
+	.buttons = da850_evm_bb_keys,
+	.nbuttons = ARRAY_SIZE(da850_evm_bb_keys),
+	.poll_interval = DA850_GPIO_KEYS_POLL_MS,
+};
+
+static struct platform_device da850_evm_bb_keys_device = {
+	.name = "gpio-keys-polled",
+	.id = 1,
+	.dev = {
+		.platform_data = &da850_evm_bb_keys_pdata
+	},
+};
+
+static void da850_evm_bb_keys_init(unsigned gpio)
+{
+	int i;
+	struct gpio_keys_button *button;
+
+	button = &da850_evm_bb_keys[0];
+	button->desc = (char *)
+		da850_evm_bb_exp[DA850_EVM_BB_EXP_USER_PB1];
+	button->gpio = gpio + DA850_EVM_BB_EXP_USER_PB1;
+
+	for (i = 0; i < DA850_N_BB_USER_SW; i++) {
+		button = &da850_evm_bb_keys[i + 1];
+		button->code = SW_LID + i;
+		button->desc = (char *)
+				da850_evm_bb_exp[DA850_EVM_BB_EXP_USER_SW1 + i];
+		button->gpio = gpio + DA850_EVM_BB_EXP_USER_SW1 + i;
+	}
+}
+
+#define DA850_N_BB_USER_LED	2
+
+static struct gpio_led da850_evm_bb_leds[] = {
+	[0 ... DA850_N_BB_USER_LED - 1] = {
+		.active_low = 1,
+		.gpio = -1, /* assigned at runtime */
+		.name = NULL, /* assigned at runtime */
+	},
+};
+
+static struct gpio_led_platform_data da850_evm_bb_leds_pdata = {
+	.leds = da850_evm_bb_leds,
+	.num_leds = ARRAY_SIZE(da850_evm_bb_leds),
+};
+
+static struct platform_device da850_evm_bb_leds_device = {
+	.name		= "leds-gpio",
+	.id		= -1,
+	.dev = {
+		.platform_data = &da850_evm_bb_leds_pdata
+	}
+};
+
+static void da850_evm_bb_leds_init(unsigned gpio)
+{
+	int i;
+	struct gpio_led *led;
+
+	for (i = 0; i < DA850_N_BB_USER_LED; i++) {
+		led = &da850_evm_bb_leds[i];
+
+		led->gpio = gpio + DA850_EVM_BB_EXP_USER_LED2 + i;
+		led->name =
+			da850_evm_bb_exp[DA850_EVM_BB_EXP_USER_LED2 + i];
+	}
+}
+
+static int da850_evm_bb_expander_setup(struct i2c_client *client,
+						unsigned gpio, unsigned ngpio,
+						void *c)
+{
+	int ret;
+
+	/*
+	 * Register the switches and pushbutton on the baseboard as a gpio-keys
+	 * device.
+	 */
+	da850_evm_bb_keys_init(gpio);
+	ret = platform_device_register(&da850_evm_bb_keys_device);
+	if (ret) {
+		pr_warning("Could not register baseboard GPIO expander keys");
+		goto io_exp_setup_sw_fail;
+	}
+
+	da850_evm_bb_leds_init(gpio);
+	ret = platform_device_register(&da850_evm_bb_leds_device);
+	if (ret) {
+		pr_warning("Could not register baseboard GPIO expander LEDS");
+		goto io_exp_setup_leds_fail;
+	}
+
+	return 0;
+
+io_exp_setup_leds_fail:
+	platform_device_unregister(&da850_evm_bb_keys_device);
+io_exp_setup_sw_fail:
+	return ret;
+}
+
+static int da850_evm_bb_expander_teardown(struct i2c_client *client,
+					unsigned gpio, unsigned ngpio, void *c)
+{
+	platform_device_unregister(&da850_evm_bb_leds_device);
+	platform_device_unregister(&da850_evm_bb_keys_device);
+
+	return 0;
+}
+
 static struct pca953x_platform_data da850_evm_ui_expander_info = {
 	.gpio_base	= DAVINCI_N_GPIO,
 	.setup		= da850_evm_ui_expander_setup,
@@ -437,6 +613,13 @@ static struct pca953x_platform_data da850_evm_ui_expander_info = {
 	.names		= da850_evm_ui_exp,
 };
 
+static struct pca953x_platform_data da850_evm_bb_expander_info = {
+	.gpio_base	= DA850_BB_EXPANDER_GPIO_BASE,
+	.setup		= da850_evm_bb_expander_setup,
+	.teardown	= da850_evm_bb_expander_teardown,
+	.names		= da850_evm_bb_exp,
+};
+
 static struct i2c_board_info __initdata da850_evm_i2c_devices[] = {
 	{
 		I2C_BOARD_INFO("tlv320aic3x", 0x18),
@@ -445,6 +628,10 @@ static struct i2c_board_info __initdata da850_evm_i2c_devices[] = {
 		I2C_BOARD_INFO("tca6416", 0x20),
 		.platform_data = &da850_evm_ui_expander_info,
 	},
+	{
+		I2C_BOARD_INFO("tca6416", 0x21),
+		.platform_data = &da850_evm_bb_expander_info,
+	},
 };
 
 static struct davinci_i2c_platform_data da850_evm_i2c_0_pdata = {