Commit 0931a4c6 authored by David Brownell's avatar David Brownell Committed by Samuel Ortiz
Browse files

mfd: dm355evm msp430 driver 



Basic MFD framework for the MSP430 microcontroller firmware used
on the dm355evm board:

 - Provides an interface for other drivers: register read/write
   utilities, and register declarations.

 - Directly exports:
     * Many signals through the GPIO framework
         + LEDs
         + SW6 through gpio sysfs
	 + NTSC/nPAL jumper through gpio sysfs
	 + ... more could be added later, e.g. MMC signals
     * Child devices:
	+ LEDs, via leds-gpio child (and default triggers)
	+ RTC, via rtc-dm355evm child device
	+ Buttons and IR control, via dm355evm_keys

 - Supports power-off system call.  Use the reset button to power
   the board back up; the power supply LED will be on, but the
   MSP430 waits to re-activate the regulators.

 - On probe() this:
     * Announces firmware revision
     * Turns off the banked LEDs
     * Exports the resources noted above
     * Hooks the power-off support
     * Muxes tvp5146 -or- imager for video input

Unless the new tvp514x driver (tracked for mainline) is configured,
this assumes that some custom imager driver handles video-in.

This completely ignores the registers reporting the output voltages
on the various power supplies.  Someone could add a hwmon interface
if that seems useful.

Signed-off-by: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: default avatarSamuel Ortiz <sameo@openedhand.com>
parent 4331bb32

drivers/mfd/Kconfig

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@@ -34,6 +34,14 @@ config MFD_ASIC3 
	  This driver supports the ASIC3 multifunction chip found on many

	  PDAs (mainly iPAQ and HTC based ones)



config MFD_DM355EVM_MSP

	bool "DaVinci DM355 EVM microcontroller"

	depends on I2C && MACH_DAVINCI_DM355_EVM

	help

	  This driver supports the MSP430 microcontroller used on these

	  boards.  MSP430 firmware manages resets and power sequencing,

	  inputs from buttons and the IR remote, LEDs, an RTC, and more.



config HTC_EGPIO

	bool "HTC EGPIO support"

	depends on GENERIC_HARDIRQS && GPIOLIB && ARM

drivers/mfd/Makefile

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@@ -8,6 +8,8 @@ obj-$(CONFIG_MFD_ASIC3) += asic3.o 
obj-$(CONFIG_HTC_EGPIO)		+= htc-egpio.o

obj-$(CONFIG_HTC_PASIC3)	+= htc-pasic3.o



obj-$(CONFIG_MFD_DM355EVM_MSP)	+= dm355evm_msp.o



obj-$(CONFIG_MFD_T7L66XB)	+= t7l66xb.o

obj-$(CONFIG_MFD_TC6387XB)	+= tc6387xb.o

obj-$(CONFIG_MFD_TC6393XB)	+= tc6393xb.o

drivers/mfd/dm355evm_msp.c

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/*

 * dm355evm_msp.c - driver for MSP430 firmware on DM355EVM board

 *

 * Copyright (C) 2008 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/init.h>

#include <linux/mutex.h>

#include <linux/platform_device.h>

#include <linux/clk.h>

#include <linux/err.h>

#include <linux/gpio.h>

#include <linux/leds.h>

#include <linux/i2c.h>

#include <linux/i2c/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 defined(CONFIG_KEYBOARD_DM355EVM) \

		|| defined(CONFIG_KEYBOARD_DM355EVM_MODULE)

#define msp_has_keyboard()	true

#else

#define msp_has_keyboard()	false

#endif



#if defined(CONFIG_LEDS_GPIO) || defined(CONFIG_LEDS_GPIO_MODULE)

#define msp_has_leds()		true

#else

#define msp_has_leds()		false

#endif



#if defined(CONFIG_RTC_DRV_DM355EVM) || defined(CONFIG_RTC_DRV_DM355EVM_MODULE)

#define msp_has_rtc()		true

#else

#define msp_has_rtc()		false

#endif



#if defined(CONFIG_VIDEO_TVP514X) || defined(CONFIG_VIDEO_TVP514X_MODULE)

#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),

};



#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) {

		dev_dbg(&client->dev, "can't alloc dev\n");

		status = -ENOMEM;

		goto err;

	}



	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 err;

		}

	}



	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 err;

		}

	}



	status = platform_device_add(pdev);



err:

	if (status < 0) {

		platform_device_put(pdev);

		dev_err(&client->dev, "can't add %s dev\n", name);

		return ERR_PTR(status);

	}

	return &pdev->dev;

}



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.dev = &client->dev;

	status = gpiochip_add(&dm355evm_msp_gpio);

	if (status < 0)

		return status;



	/* LED output */

	if (msp_has_leds()) {

#define GPIO_LED(l)	.name = l, .active_low = true

		static struct gpio_led evm_leds[] = {

			{ GPIO_LED("dm355evm::ds14"),

				.default_trigger = "heartbeat", },

			{ GPIO_LED("dm355evm::ds15"),

				.default_trigger = "mmc0", },

			{ GPIO_LED("dm355evm::ds16"),

				/* could also be a CE-ATA drive */

				.default_trigger = "mmc1", },

			{ GPIO_LED("dm355evm::ds17"),

				.default_trigger = "nand-disk", },

			{ GPIO_LED("dm355evm::ds18"), },

			{ GPIO_LED("dm355evm::ds19"), },

			{ GPIO_LED("dm355evm::ds20"), },

			{ GPIO_LED("dm355evm::ds21"), },

		};

#undef GPIO_LED



		struct gpio_led_platform_data evm_led_data = {

			.num_leds	= ARRAY_SIZE(evm_leds),

			.leds		= evm_leds,

		};



		for (i = 0; i < ARRAY_SIZE(evm_leds); i++)

			evm_leds[i].gpio = i + dm355evm_msp_gpio.base;



		/* 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(gpio, config_inputs[i].label);

		gpio_direction_input(gpio);



		/* make it easy for userspace to see these */

		gpio_export(gpio, false);

	}



	/* 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 int dm355evm_msp_remove(struct i2c_client *client)

{

	pm_power_off = NULL;

	msp430 = NULL;

	return 0;

}



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");

include/linux/i2c/dm355evm_msp.h

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/*

 * dm355evm_msp.h - support MSP430 microcontroller on DM355EVM board

 */

#ifndef __LINUX_I2C_DM355EVM_MSP

#define __LINUX_I2C_DM355EVM_MSP



/*

 * Written against Spectrum's writeup for the A4 firmware revision,

 * and tweaked to match source and rev D2 schematics by removing CPLD

 * and NOR flash hooks (which were last appropriate in rev B boards).

 *

 * Note that the firmware supports a flavor of write posting ... to be

 * sure a write completes, issue another read or write.

 */



/* utilities to access "registers" emulated by msp430 firmware */

extern int dm355evm_msp_write(u8 value, u8 reg);

extern int dm355evm_msp_read(u8 reg);





/* command/control registers */

#define DM355EVM_MSP_COMMAND		0x00

#	define MSP_COMMAND_NULL		0

#	define MSP_COMMAND_RESET_COLD	1

#	define MSP_COMMAND_RESET_WARM	2

#	define MSP_COMMAND_RESET_WARM_I	3

#	define MSP_COMMAND_POWEROFF	4

#	define MSP_COMMAND_IR_REINIT	5

#define DM355EVM_MSP_STATUS		0x01

#	define MSP_STATUS_BAD_OFFSET	BIT(0)

#	define MSP_STATUS_BAD_COMMAND	BIT(1)

#	define MSP_STATUS_POWER_ERROR	BIT(2)

#	define MSP_STATUS_RXBUF_OVERRUN	BIT(3)

#define DM355EVM_MSP_RESET		0x02	/* 0 bits == in reset */

#	define MSP_RESET_DC5		BIT(0)

#	define MSP_RESET_TVP5154	BIT(2)

#	define MSP_RESET_IMAGER		BIT(3)

#	define MSP_RESET_ETHERNET	BIT(4)

#	define MSP_RESET_SYS		BIT(5)

#	define MSP_RESET_AIC33		BIT(7)



/* GPIO registers ... bit patterns mostly match the source MSP ports */

#define DM355EVM_MSP_LED		0x03	/* active low (MSP P4) */

#define DM355EVM_MSP_SWITCH1		0x04	/* (MSP P5, masked) */

#	define MSP_SWITCH1_SW6_1	BIT(0)

#	define MSP_SWITCH1_SW6_2	BIT(1)

#	define MSP_SWITCH1_SW6_3	BIT(2)

#	define MSP_SWITCH1_SW6_4	BIT(3)

#	define MSP_SWITCH1_J1		BIT(4)	/* NTSC/PAL */

#	define MSP_SWITCH1_MSP_INT	BIT(5)	/* active low */

#define DM355EVM_MSP_SWITCH2		0x05	/* (MSP P6, masked) */

#	define MSP_SWITCH2_SW10		BIT(3)

#	define MSP_SWITCH2_SW11		BIT(4)

#	define MSP_SWITCH2_SW12		BIT(5)

#	define MSP_SWITCH2_SW13		BIT(6)

#	define MSP_SWITCH2_SW14		BIT(7)

#define DM355EVM_MSP_SDMMC		0x06	/* (MSP P2, masked) */

#	define MSP_SDMMC_0_WP		BIT(1)

#	define MSP_SDMMC_0_CD		BIT(2)	/* active low */

#	define MSP_SDMMC_1_WP		BIT(3)

#	define MSP_SDMMC_1_CD		BIT(4)	/* active low */

#define DM355EVM_MSP_FIRMREV		0x07	/* not a GPIO (out of order) */

#define DM355EVM_MSP_VIDEO_IN		0x08	/* (MSP P3, masked) */

#	define MSP_VIDEO_IMAGER		BIT(7)	/* low == tvp5146 */



/* power supply registers are currently omitted */



/* RTC registers */

#define DM355EVM_MSP_RTC_0		0x12	/* LSB */

#define DM355EVM_MSP_RTC_1		0x13

#define DM355EVM_MSP_RTC_2		0x14

#define DM355EVM_MSP_RTC_3		0x15	/* MSB */



/* input event queue registers; code == ((HIGH << 8) | LOW) */

#define DM355EVM_MSP_INPUT_COUNT	0x16	/* decrement by reading LOW */

#define DM355EVM_MSP_INPUT_HIGH		0x17

#define DM355EVM_MSP_INPUT_LOW		0x18



#endif /* __LINUX_I2C_DM355EVM_MSP */

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