drivers/mfd/dm355evm_msp.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * dm355evm_msp.c - driver for MSP430 firmware on DM355EVM board
  *
  * Copyright (C) 2008 David Brownell
  */

 #include <linux/init.h>
 #include <linux/mutex.h>
 #include <linux/platform_device.h>
 #include <linux/clk.h>
 #include <linux/module.h>
 #include <linux/err.h>
 #include <linux/gpio.h>
 #include <linux/gpio/machine.h>
 #include <linux/leds.h>
 #include <linux/i2c.h>
 #include <linux/mfd/dm355evm_msp.h>


 /*
  * The DM355 is a DaVinci chip with video support but no C64+ DSP.  Its
  * EVM board has an MSP430 programmed with firmware for various board
  * support functions.  This driver exposes some of them directly, and
  * supports other drivers (e.g. RTC, input) for more complex access.
  *
  * Because this firmware is entirely board-specific, this file embeds
  * knowledge that would be passed as platform_data in a generic driver.
  *
  * This driver was tested with firmware revision A4.
  */

 #if IS_ENABLED(CONFIG_INPUT_DM355EVM)
 #define msp_has_keyboard()	true
 #else
 #define msp_has_keyboard()	false
 #endif

 #if IS_ENABLED(CONFIG_LEDS_GPIO)
 #define msp_has_leds()		true
 #else
 #define msp_has_leds()		false
 #endif

 #if IS_ENABLED(CONFIG_RTC_DRV_DM355EVM)
 #define msp_has_rtc()		true
 #else
 #define msp_has_rtc()		false
 #endif

 #if IS_ENABLED(CONFIG_VIDEO_TVP514X)
 #define msp_has_tvp()		true
 #else
 #define msp_has_tvp()		false
 #endif


 /*----------------------------------------------------------------------*/

 /* REVISIT for paranoia's sake, retry reads/writes on error */

 static struct i2c_client *msp430;

 /**
  * dm355evm_msp_write - Writes a register in dm355evm_msp
  * @value: the value to be written
  * @reg: register address
  *
  * Returns result of operation - 0 is success, else negative errno
  */
 int dm355evm_msp_write(u8 value, u8 reg)
 {
 	return i2c_smbus_write_byte_data(msp430, reg, value);
 }
 EXPORT_SYMBOL(dm355evm_msp_write);

 /**
  * dm355evm_msp_read - Reads a register from dm355evm_msp
  * @reg: register address
  *
  * Returns result of operation - value, or negative errno
  */
 int dm355evm_msp_read(u8 reg)
 {
 	return i2c_smbus_read_byte_data(msp430, reg);
 }
 EXPORT_SYMBOL(dm355evm_msp_read);

 /*----------------------------------------------------------------------*/

 /*
  * Many of the msp430 pins are just used as fixed-direction GPIOs.
  * We could export a few more of them this way, if we wanted.
  */
 #define MSP_GPIO(bit, reg)	((DM355EVM_MSP_ ## reg) << 3 | (bit))

 static const u8 msp_gpios[] = {
 	/* eight leds */
 	MSP_GPIO(0, LED), MSP_GPIO(1, LED),
 	MSP_GPIO(2, LED), MSP_GPIO(3, LED),
 	MSP_GPIO(4, LED), MSP_GPIO(5, LED),
 	MSP_GPIO(6, LED), MSP_GPIO(7, LED),
 	/* SW6 and the NTSC/nPAL jumper */
 	MSP_GPIO(0, SWITCH1), MSP_GPIO(1, SWITCH1),
 	MSP_GPIO(2, SWITCH1), MSP_GPIO(3, SWITCH1),
 	MSP_GPIO(4, SWITCH1),
 	/* switches on MMC/SD sockets */
 	/*
 	 * Note: EVMDM355_ECP_VA4.pdf suggests that Bit 2 and 4 should be
 	 * checked for card detection. However on the EVM bit 1 and 3 gives
 	 * this status, for 0 and 1 instance respectively. The pdf also
 	 * suggests that Bit 1 and 3 should be checked for write protection.
 	 * However on the EVM bit 2 and 4 gives this status,for 0 and 1
 	 * instance respectively.
 	 */
 	MSP_GPIO(2, SDMMC), MSP_GPIO(1, SDMMC),	/* mmc0 WP, nCD */
 	MSP_GPIO(4, SDMMC), MSP_GPIO(3, SDMMC),	/* mmc1 WP, nCD */
 };

 static struct gpio_led evm_leds[] = {
 	{ .name = "dm355evm::ds14",
 	  .default_trigger = "heartbeat", },
 	{ .name = "dm355evm::ds15",
 	  .default_trigger = "mmc0", },
 	{ .name = "dm355evm::ds16",
 	  /* could also be a CE-ATA drive */
 	  .default_trigger = "mmc1", },
 	{ .name = "dm355evm::ds17",
 	  .default_trigger = "nand-disk", },
 	{ .name = "dm355evm::ds18", },
 	{ .name = "dm355evm::ds19", },
 	{ .name = "dm355evm::ds20", },
 	{ .name = "dm355evm::ds21", },
 };

 static struct gpio_led_platform_data evm_led_data = {
 	.num_leds	= ARRAY_SIZE(evm_leds),
 	.leds		= evm_leds,
 };

 static struct gpiod_lookup_table evm_leds_gpio_table = {
 	.dev_id = "leds-gpio",
 	.table = {
 		/*
 		 * These GPIOs are on the dm355evm_msp
 		 * GPIO chip at index 0..7
 		 */
 		GPIO_LOOKUP_IDX("dm355evm_msp", 0, NULL,
 				0, GPIO_ACTIVE_LOW),
 		GPIO_LOOKUP_IDX("dm355evm_msp", 1, NULL,
 				1, GPIO_ACTIVE_LOW),
 		GPIO_LOOKUP_IDX("dm355evm_msp", 2, NULL,
 				2, GPIO_ACTIVE_LOW),
 		GPIO_LOOKUP_IDX("dm355evm_msp", 3, NULL,
 				3, GPIO_ACTIVE_LOW),
 		GPIO_LOOKUP_IDX("dm355evm_msp", 4, NULL,
 				4, GPIO_ACTIVE_LOW),
 		GPIO_LOOKUP_IDX("dm355evm_msp", 5, NULL,
 				5, GPIO_ACTIVE_LOW),
 		GPIO_LOOKUP_IDX("dm355evm_msp", 6, NULL,
 				6, GPIO_ACTIVE_LOW),
 		GPIO_LOOKUP_IDX("dm355evm_msp", 7, NULL,
 				7, GPIO_ACTIVE_LOW),
 		{ },
 	},
 };

 #define MSP_GPIO_REG(offset)	(msp_gpios[(offset)] >> 3)
 #define MSP_GPIO_MASK(offset)	BIT(msp_gpios[(offset)] & 0x07)

 static int msp_gpio_in(struct gpio_chip *chip, unsigned offset)
 {
 	switch (MSP_GPIO_REG(offset)) {
 	case DM355EVM_MSP_SWITCH1:
 	case DM355EVM_MSP_SWITCH2:
 	case DM355EVM_MSP_SDMMC:
 		return 0;
 	default:
 		return -EINVAL;
 	}
 }

 static u8 msp_led_cache;

 static int msp_gpio_get(struct gpio_chip *chip, unsigned offset)
 {
 	int reg, status;

 	reg = MSP_GPIO_REG(offset);
 	status = dm355evm_msp_read(reg);
 	if (status < 0)
 		return status;
 	if (reg == DM355EVM_MSP_LED)
 		msp_led_cache = status;
 	return !!(status & MSP_GPIO_MASK(offset));
 }

 static int msp_gpio_out(struct gpio_chip *chip, unsigned offset, int value)
 {
 	int mask, bits;

 	/* NOTE:  there are some other signals that could be
 	 * packaged as output GPIOs, but they aren't as useful
 	 * as the LEDs ... so for now we don't.
 	 */
 	if (MSP_GPIO_REG(offset) != DM355EVM_MSP_LED)
 		return -EINVAL;

 	mask = MSP_GPIO_MASK(offset);
 	bits = msp_led_cache;

 	bits &= ~mask;
 	if (value)
 		bits |= mask;
 	msp_led_cache = bits;

 	return dm355evm_msp_write(bits, DM355EVM_MSP_LED);
 }

 static void msp_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
 {
 	msp_gpio_out(chip, offset, value);
 }

 static struct gpio_chip dm355evm_msp_gpio = {
 	.label			= "dm355evm_msp",
 	.owner			= THIS_MODULE,
 	.direction_input	= msp_gpio_in,
 	.get			= msp_gpio_get,
 	.direction_output	= msp_gpio_out,
 	.set			= msp_gpio_set,
 	.base			= -EINVAL,		/* dynamic assignment */
 	.ngpio			= ARRAY_SIZE(msp_gpios),
 	.can_sleep		= true,
 };

 /*----------------------------------------------------------------------*/

 static struct device *add_child(struct i2c_client *client, const char *name,
 		void *pdata, unsigned pdata_len,
 		bool can_wakeup, int irq)
 {
 	struct platform_device	*pdev;
 	int			status;

 	pdev = platform_device_alloc(name, -1);
 	if (!pdev)
 		return ERR_PTR(-ENOMEM);

 	device_init_wakeup(&pdev->dev, can_wakeup);
 	pdev->dev.parent = &client->dev;

 	if (pdata) {
 		status = platform_device_add_data(pdev, pdata, pdata_len);
 		if (status < 0) {
 			dev_dbg(&pdev->dev, "can't add platform_data\n");
 			goto put_device;
 		}
 	}

 	if (irq) {
 		struct resource r = {
 			.start = irq,
 			.flags = IORESOURCE_IRQ,
 		};

 		status = platform_device_add_resources(pdev, &r, 1);
 		if (status < 0) {
 			dev_dbg(&pdev->dev, "can't add irq\n");
 			goto put_device;
 		}
 	}

 	status = platform_device_add(pdev);
 	if (status)
 		goto put_device;

 	return &pdev->dev;

 put_device:
 	platform_device_put(pdev);
 	dev_err(&client->dev, "failed to add device %s\n", name);
 	return ERR_PTR(status);
 }

 static int add_children(struct i2c_client *client)
 {
 	static const struct {
 		int offset;
 		char *label;
 	} config_inputs[] = {
 		/* 8 == right after the LEDs */
 		{ 8 + 0, "sw6_1", },
 		{ 8 + 1, "sw6_2", },
 		{ 8 + 2, "sw6_3", },
 		{ 8 + 3, "sw6_4", },
 		{ 8 + 4, "NTSC/nPAL", },
 	};

 	struct device	*child;
 	int		status;
 	int		i;

 	/* GPIO-ish stuff */
 	dm355evm_msp_gpio.parent = &client->dev;
 	status = gpiochip_add_data(&dm355evm_msp_gpio, NULL);
 	if (status < 0)
 		return status;

 	/* LED output */
 	if (msp_has_leds()) {
 		gpiod_add_lookup_table(&evm_leds_gpio_table);
 		/* NOTE:  these are the only fully programmable LEDs
 		 * on the board, since GPIO-61/ds22 (and many signals
 		 * going to DC7) must be used for AEMIF address lines
 		 * unless the top 1 GB of NAND is unused...
 		 */
 		child = add_child(client, "leds-gpio",
 				&evm_led_data, sizeof(evm_led_data),
 				false, 0);
 		if (IS_ERR(child))
 			return PTR_ERR(child);
 	}

 	/* configuration inputs */
 	for (i = 0; i < ARRAY_SIZE(config_inputs); i++) {
 		int gpio = dm355evm_msp_gpio.base + config_inputs[i].offset;

 		gpio_request_one(gpio, GPIOF_IN, config_inputs[i].label);

 		/* make it easy for userspace to see these */
 		gpio_export(gpio, false);
 	}

 	/* MMC/SD inputs -- right after the last config input */
 	if (dev_get_platdata(&client->dev)) {
 		void (*mmcsd_setup)(unsigned) = dev_get_platdata(&client->dev);

 		mmcsd_setup(dm355evm_msp_gpio.base + 8 + 5);
 	}

 	/* RTC is a 32 bit counter, no alarm */
 	if (msp_has_rtc()) {
 		child = add_child(client, "rtc-dm355evm",
 				NULL, 0, false, 0);
 		if (IS_ERR(child))
 			return PTR_ERR(child);
 	}

 	/* input from buttons and IR remote (uses the IRQ) */
 	if (msp_has_keyboard()) {
 		child = add_child(client, "dm355evm_keys",
 				NULL, 0, true, client->irq);
 		if (IS_ERR(child))
 			return PTR_ERR(child);
 	}

 	return 0;
 }

 /*----------------------------------------------------------------------*/

 static void dm355evm_command(unsigned command)
 {
 	int status;

 	status = dm355evm_msp_write(command, DM355EVM_MSP_COMMAND);
 	if (status < 0)
 		dev_err(&msp430->dev, "command %d failure %d\n",
 				command, status);
 }

 static void dm355evm_power_off(void)
 {
 	dm355evm_command(MSP_COMMAND_POWEROFF);
 }

 static void dm355evm_msp_remove(struct i2c_client *client)
 {
 	pm_power_off = NULL;
 	msp430 = NULL;
 }

 static int
 dm355evm_msp_probe(struct i2c_client *client, const struct i2c_device_id *id)
 {
 	int		status;
 	const char	*video = msp_has_tvp() ? "TVP5146" : "imager";

 	if (msp430)
 		return -EBUSY;
 	msp430 = client;

 	/* display revision status; doubles as sanity check */
 	status = dm355evm_msp_read(DM355EVM_MSP_FIRMREV);
 	if (status < 0)
 		goto fail;
 	dev_info(&client->dev, "firmware v.%02X, %s as video-in\n",
 			status, video);

 	/* mux video input:  either tvp5146 or some external imager */
 	status = dm355evm_msp_write(msp_has_tvp() ? 0 : MSP_VIDEO_IMAGER,
 			DM355EVM_MSP_VIDEO_IN);
 	if (status < 0)
 		dev_warn(&client->dev, "error %d muxing %s as video-in\n",
 			status, video);

 	/* init LED cache, and turn off the LEDs */
 	msp_led_cache = 0xff;
 	dm355evm_msp_write(msp_led_cache, DM355EVM_MSP_LED);

 	/* export capabilities we support */
 	status = add_children(client);
 	if (status < 0)
 		goto fail;

 	/* PM hookup */
 	pm_power_off = dm355evm_power_off;

 	return 0;

 fail:
 	/* FIXME remove children ... */
 	dm355evm_msp_remove(client);
 	return status;
 }

 static const struct i2c_device_id dm355evm_msp_ids[] = {
 	{ "dm355evm_msp", 0 },
 	{ /* end of list */ },
 };
 MODULE_DEVICE_TABLE(i2c, dm355evm_msp_ids);

 static struct i2c_driver dm355evm_msp_driver = {
 	.driver.name	= "dm355evm_msp",
 	.id_table	= dm355evm_msp_ids,
 	.probe		= dm355evm_msp_probe,
 	.remove		= dm355evm_msp_remove,
 };

 static int __init dm355evm_msp_init(void)
 {
 	return i2c_add_driver(&dm355evm_msp_driver);
 }
 subsys_initcall(dm355evm_msp_init);

 static void __exit dm355evm_msp_exit(void)
 {
 	i2c_del_driver(&dm355evm_msp_driver);
 }
 module_exit(dm355evm_msp_exit);

 MODULE_DESCRIPTION("Interface to MSP430 firmware on DM355EVM");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* dm355evm_msp.c - driver for MSP430 firmware on DM355EVM board
	*
	* Copyright (C) 2008 David Brownell
	*/

	#include <linux/init.h>
	#include <linux/mutex.h>
	#include <linux/platform_device.h>
	#include <linux/clk.h>
	#include <linux/module.h>
	#include <linux/err.h>
	#include <linux/gpio.h>
	#include <linux/gpio/machine.h>
	#include <linux/leds.h>
	#include <linux/i2c.h>
	#include <linux/mfd/dm355evm_msp.h>


	/*
	* The DM355 is a DaVinci chip with video support but no C64+ DSP. Its
	* EVM board has an MSP430 programmed with firmware for various board
	* support functions. This driver exposes some of them directly, and
	* supports other drivers (e.g. RTC, input) for more complex access.
	*
	* Because this firmware is entirely board-specific, this file embeds
	* knowledge that would be passed as platform_data in a generic driver.
	*
	* This driver was tested with firmware revision A4.
	*/

	#if IS_ENABLED(CONFIG_INPUT_DM355EVM)
	#define msp_has_keyboard() true
	#else
	#define msp_has_keyboard() false
	#endif

	#if IS_ENABLED(CONFIG_LEDS_GPIO)
	#define msp_has_leds() true
	#else
	#define msp_has_leds() false
	#endif

	#if IS_ENABLED(CONFIG_RTC_DRV_DM355EVM)
	#define msp_has_rtc() true
	#else
	#define msp_has_rtc() false
	#endif

	#if IS_ENABLED(CONFIG_VIDEO_TVP514X)
	#define msp_has_tvp() true
	#else
	#define msp_has_tvp() false
	#endif


	/----------------------------------------------------------------------/

	/* REVISIT for paranoia's sake, retry reads/writes on error */

	static struct i2c_client *msp430;

	/**
	* dm355evm_msp_write - Writes a register in dm355evm_msp
	* @value: the value to be written
	* @reg: register address
	*
	* Returns result of operation - 0 is success, else negative errno
	*/
	int dm355evm_msp_write(u8 value, u8 reg)
	{
	return i2c_smbus_write_byte_data(msp430, reg, value);
	}
	EXPORT_SYMBOL(dm355evm_msp_write);

	/**
	* dm355evm_msp_read - Reads a register from dm355evm_msp
	* @reg: register address
	*
	* Returns result of operation - value, or negative errno
	*/
	int dm355evm_msp_read(u8 reg)
	{
	return i2c_smbus_read_byte_data(msp430, reg);
	}
	EXPORT_SYMBOL(dm355evm_msp_read);

	/----------------------------------------------------------------------/

	/*
	* Many of the msp430 pins are just used as fixed-direction GPIOs.
	* We could export a few more of them this way, if we wanted.
	*/
	#define MSP_GPIO(bit, reg) ((DM355EVM_MSP_ ## reg) << 3 \| (bit))

	static const u8 msp_gpios[] = {
	/* eight leds */
	MSP_GPIO(0, LED), MSP_GPIO(1, LED),
	MSP_GPIO(2, LED), MSP_GPIO(3, LED),
	MSP_GPIO(4, LED), MSP_GPIO(5, LED),
	MSP_GPIO(6, LED), MSP_GPIO(7, LED),
	/* SW6 and the NTSC/nPAL jumper */
	MSP_GPIO(0, SWITCH1), MSP_GPIO(1, SWITCH1),
	MSP_GPIO(2, SWITCH1), MSP_GPIO(3, SWITCH1),
	MSP_GPIO(4, SWITCH1),
	/* switches on MMC/SD sockets */
	/*
	* Note: EVMDM355_ECP_VA4.pdf suggests that Bit 2 and 4 should be
	* checked for card detection. However on the EVM bit 1 and 3 gives
	* this status, for 0 and 1 instance respectively. The pdf also
	* suggests that Bit 1 and 3 should be checked for write protection.
	* However on the EVM bit 2 and 4 gives this status,for 0 and 1
	* instance respectively.
	*/
	MSP_GPIO(2, SDMMC), MSP_GPIO(1, SDMMC), /* mmc0 WP, nCD */
	MSP_GPIO(4, SDMMC), MSP_GPIO(3, SDMMC), /* mmc1 WP, nCD */
	};

	static struct gpio_led evm_leds[] = {
	{ .name = "dm355evm::ds14",
	.default_trigger = "heartbeat", },
	{ .name = "dm355evm::ds15",
	.default_trigger = "mmc0", },
	{ .name = "dm355evm::ds16",
	/* could also be a CE-ATA drive */
	.default_trigger = "mmc1", },
	{ .name = "dm355evm::ds17",
	.default_trigger = "nand-disk", },
	{ .name = "dm355evm::ds18", },
	{ .name = "dm355evm::ds19", },
	{ .name = "dm355evm::ds20", },
	{ .name = "dm355evm::ds21", },
	};

	static struct gpio_led_platform_data evm_led_data = {
	.num_leds = ARRAY_SIZE(evm_leds),
	.leds = evm_leds,
	};

	static struct gpiod_lookup_table evm_leds_gpio_table = {
	.dev_id = "leds-gpio",
	.table = {
	/*
	* These GPIOs are on the dm355evm_msp
	* GPIO chip at index 0..7
	*/
	GPIO_LOOKUP_IDX("dm355evm_msp", 0, NULL,
	0, GPIO_ACTIVE_LOW),
	GPIO_LOOKUP_IDX("dm355evm_msp", 1, NULL,
	1, GPIO_ACTIVE_LOW),
	GPIO_LOOKUP_IDX("dm355evm_msp", 2, NULL,
	2, GPIO_ACTIVE_LOW),
	GPIO_LOOKUP_IDX("dm355evm_msp", 3, NULL,
	3, GPIO_ACTIVE_LOW),
	GPIO_LOOKUP_IDX("dm355evm_msp", 4, NULL,
	4, GPIO_ACTIVE_LOW),
	GPIO_LOOKUP_IDX("dm355evm_msp", 5, NULL,
	5, GPIO_ACTIVE_LOW),
	GPIO_LOOKUP_IDX("dm355evm_msp", 6, NULL,
	6, GPIO_ACTIVE_LOW),
	GPIO_LOOKUP_IDX("dm355evm_msp", 7, NULL,
	7, GPIO_ACTIVE_LOW),
	{ },
	},
	};

	#define MSP_GPIO_REG(offset) (msp_gpios[(offset)] >> 3)
	#define MSP_GPIO_MASK(offset) BIT(msp_gpios[(offset)] & 0x07)

	static int msp_gpio_in(struct gpio_chip *chip, unsigned offset)
	{
	switch (MSP_GPIO_REG(offset)) {
	case DM355EVM_MSP_SWITCH1:
	case DM355EVM_MSP_SWITCH2:
	case DM355EVM_MSP_SDMMC:
	return 0;
	default:
	return -EINVAL;
	}
	}

	static u8 msp_led_cache;

	static int msp_gpio_get(struct gpio_chip *chip, unsigned offset)
	{
	int reg, status;

	reg = MSP_GPIO_REG(offset);
	status = dm355evm_msp_read(reg);
	if (status < 0)
	return status;
	if (reg == DM355EVM_MSP_LED)
	msp_led_cache = status;
	return !!(status & MSP_GPIO_MASK(offset));
	}

	static int msp_gpio_out(struct gpio_chip *chip, unsigned offset, int value)
	{
	int mask, bits;

	/* NOTE: there are some other signals that could be
	* packaged as output GPIOs, but they aren't as useful
	* as the LEDs ... so for now we don't.
	*/
	if (MSP_GPIO_REG(offset) != DM355EVM_MSP_LED)
	return -EINVAL;

	mask = MSP_GPIO_MASK(offset);
	bits = msp_led_cache;

	bits &= ~mask;
	if (value)
	bits \|= mask;
	msp_led_cache = bits;

	return dm355evm_msp_write(bits, DM355EVM_MSP_LED);
	}

	static void msp_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
	{
	msp_gpio_out(chip, offset, value);
	}

	static struct gpio_chip dm355evm_msp_gpio = {
	.label = "dm355evm_msp",
	.owner = THIS_MODULE,
	.direction_input = msp_gpio_in,
	.get = msp_gpio_get,
	.direction_output = msp_gpio_out,
	.set = msp_gpio_set,
	.base = -EINVAL, /* dynamic assignment */
	.ngpio = ARRAY_SIZE(msp_gpios),
	.can_sleep = true,
	};

	/----------------------------------------------------------------------/

	static struct device add_child(struct i2c_client client, const char *name,
	void *pdata, unsigned pdata_len,
	bool can_wakeup, int irq)
	{
	struct platform_device *pdev;
	int status;

	pdev = platform_device_alloc(name, -1);
	if (!pdev)
	return ERR_PTR(-ENOMEM);

	device_init_wakeup(&pdev->dev, can_wakeup);
	pdev->dev.parent = &client->dev;

	if (pdata) {
	status = platform_device_add_data(pdev, pdata, pdata_len);
	if (status < 0) {
	dev_dbg(&pdev->dev, "can't add platform_data\n");
	goto put_device;
	}
	}

	if (irq) {
	struct resource r = {
	.start = irq,
	.flags = IORESOURCE_IRQ,
	};

	status = platform_device_add_resources(pdev, &r, 1);
	if (status < 0) {
	dev_dbg(&pdev->dev, "can't add irq\n");
	goto put_device;
	}
	}

	status = platform_device_add(pdev);
	if (status)
	goto put_device;

	return &pdev->dev;

	put_device:
	platform_device_put(pdev);
	dev_err(&client->dev, "failed to add device %s\n", name);
	return ERR_PTR(status);
	}

	static int add_children(struct i2c_client *client)
	{
	static const struct {
	int offset;
	char *label;
	} config_inputs[] = {
	/* 8 == right after the LEDs */
	{ 8 + 0, "sw6_1", },
	{ 8 + 1, "sw6_2", },
	{ 8 + 2, "sw6_3", },
	{ 8 + 3, "sw6_4", },
	{ 8 + 4, "NTSC/nPAL", },
	};

	struct device *child;
	int status;
	int i;

	/* GPIO-ish stuff */
	dm355evm_msp_gpio.parent = &client->dev;
	status = gpiochip_add_data(&dm355evm_msp_gpio, NULL);
	if (status < 0)
	return status;

	/* LED output */
	if (msp_has_leds()) {
	gpiod_add_lookup_table(&evm_leds_gpio_table);
	/* NOTE: these are the only fully programmable LEDs
	* on the board, since GPIO-61/ds22 (and many signals
	* going to DC7) must be used for AEMIF address lines
	* unless the top 1 GB of NAND is unused...
	*/
	child = add_child(client, "leds-gpio",
	&evm_led_data, sizeof(evm_led_data),
	false, 0);
	if (IS_ERR(child))
	return PTR_ERR(child);
	}

	/* configuration inputs */
	for (i = 0; i < ARRAY_SIZE(config_inputs); i++) {
	int gpio = dm355evm_msp_gpio.base + config_inputs[i].offset;

	gpio_request_one(gpio, GPIOF_IN, config_inputs[i].label);

	/* make it easy for userspace to see these */
	gpio_export(gpio, false);
	}

	/* MMC/SD inputs -- right after the last config input */
	if (dev_get_platdata(&client->dev)) {
	void (*mmcsd_setup)(unsigned) = dev_get_platdata(&client->dev);

	mmcsd_setup(dm355evm_msp_gpio.base + 8 + 5);
	}

	/* RTC is a 32 bit counter, no alarm */
	if (msp_has_rtc()) {
	child = add_child(client, "rtc-dm355evm",
	NULL, 0, false, 0);
	if (IS_ERR(child))
	return PTR_ERR(child);
	}

	/* input from buttons and IR remote (uses the IRQ) */
	if (msp_has_keyboard()) {
	child = add_child(client, "dm355evm_keys",
	NULL, 0, true, client->irq);
	if (IS_ERR(child))
	return PTR_ERR(child);
	}

	return 0;
	}

	/----------------------------------------------------------------------/

	static void dm355evm_command(unsigned command)
	{
	int status;

	status = dm355evm_msp_write(command, DM355EVM_MSP_COMMAND);
	if (status < 0)
	dev_err(&msp430->dev, "command %d failure %d\n",
	command, status);
	}

	static void dm355evm_power_off(void)
	{
	dm355evm_command(MSP_COMMAND_POWEROFF);
	}

	static void dm355evm_msp_remove(struct i2c_client *client)
	{
	pm_power_off = NULL;
	msp430 = NULL;
	}

	static int
	dm355evm_msp_probe(struct i2c_client client, const struct i2c_device_id id)
	{
	int status;
	const char *video = msp_has_tvp() ? "TVP5146" : "imager";

	if (msp430)
	return -EBUSY;
	msp430 = client;

	/* display revision status; doubles as sanity check */
	status = dm355evm_msp_read(DM355EVM_MSP_FIRMREV);
	if (status < 0)
	goto fail;
	dev_info(&client->dev, "firmware v.%02X, %s as video-in\n",
	status, video);

	/* mux video input: either tvp5146 or some external imager */
	status = dm355evm_msp_write(msp_has_tvp() ? 0 : MSP_VIDEO_IMAGER,
	DM355EVM_MSP_VIDEO_IN);
	if (status < 0)
	dev_warn(&client->dev, "error %d muxing %s as video-in\n",
	status, video);

	/* init LED cache, and turn off the LEDs */
	msp_led_cache = 0xff;
	dm355evm_msp_write(msp_led_cache, DM355EVM_MSP_LED);

	/* export capabilities we support */
	status = add_children(client);
	if (status < 0)
	goto fail;

	/* PM hookup */
	pm_power_off = dm355evm_power_off;

	return 0;

	fail:
	/* FIXME remove children ... */
	dm355evm_msp_remove(client);
	return status;
	}

	static const struct i2c_device_id dm355evm_msp_ids[] = {
	{ "dm355evm_msp", 0 },
	{ /* end of list */ },
	};
	MODULE_DEVICE_TABLE(i2c, dm355evm_msp_ids);

	static struct i2c_driver dm355evm_msp_driver = {
	.driver.name = "dm355evm_msp",
	.id_table = dm355evm_msp_ids,
	.probe = dm355evm_msp_probe,
	.remove = dm355evm_msp_remove,
	};

	static int __init dm355evm_msp_init(void)
	{
	return i2c_add_driver(&dm355evm_msp_driver);
	}
	subsys_initcall(dm355evm_msp_init);

	static void __exit dm355evm_msp_exit(void)
	{
	i2c_del_driver(&dm355evm_msp_driver);
	}
	module_exit(dm355evm_msp_exit);

	MODULE_DESCRIPTION("Interface to MSP430 firmware on DM355EVM");
	MODULE_LICENSE("GPL");