Commit e9d35947 authored by David Brownell's avatar David Brownell Committed by Samuel Ortiz
Browse files

mfd: twl4030-gpio driver 



This adds basic support for the GPIOs in the twl4030 power management
chip.  That includes two open drain LED drivers, and the use of GPIO-0
(and GPIO-1) as MMC/SD card detect switches which can control whether
the VMMC1 (and VMMC2) regulators are active.

This version of the code has a debounce call that will probably be
replaced before long, when a more generic interface exists.

Signed-off-by: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: default avatarTony Lindgren <tony@atomide.com>
Signed-off-by: default avatarSamuel Ortiz <sameo@openedhand.com>
parent f96411ab

drivers/gpio/Kconfig

+7 −0
Original line number Diff line number Diff line
@@ -127,6 +127,13 @@ config GPIO_PCF857X 
	  This driver provides an in-kernel interface to those GPIOs using

	  platform-neutral GPIO calls.



config GPIO_TWL4030

	tristate "TWL4030, TWL5030, and TPS659x0 GPIOs"

	depends on TWL4030_CORE

	help

	  Say yes here to access the GPIO signals of various multi-function

	  power management chips from Texas Instruments.



comment "PCI GPIO expanders:"



config GPIO_BT8XX

drivers/gpio/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -9,4 +9,5 @@ obj-$(CONFIG_GPIO_MAX732X) += max732x.o 
obj-$(CONFIG_GPIO_MCP23S08)	+= mcp23s08.o

obj-$(CONFIG_GPIO_PCA953X)	+= pca953x.o

obj-$(CONFIG_GPIO_PCF857X)	+= pcf857x.o

obj-$(CONFIG_GPIO_TWL4030)	+= twl4030-gpio.o

obj-$(CONFIG_GPIO_BT8XX)	+= bt8xxgpio.o

drivers/gpio/twl4030-gpio.c

0 → 100644
+521 −0
Original line number Diff line number Diff line 
/*

 * twl4030_gpio.c -- access to GPIOs on TWL4030/TPS659x0 chips

 *

 * Copyright (C) 2006-2007 Texas Instruments, Inc.

 * Copyright (C) 2006 MontaVista Software, Inc.

 *

 * Code re-arranged and cleaned up by:

 *	Syed Mohammed Khasim <x0khasim@ti.com>

 *

 * Initial Code:

 *	Andy Lowe / Nishanth Menon

 *

 * 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.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA

 */



#include <linux/module.h>

#include <linux/init.h>

#include <linux/interrupt.h>

#include <linux/kthread.h>

#include <linux/irq.h>

#include <linux/gpio.h>

#include <linux/platform_device.h>

#include <linux/slab.h>



#include <linux/i2c/twl4030.h>





/*

 * The GPIO "subchip" supports 18 GPIOs which can be configured as

 * inputs or outputs, with pullups or pulldowns on each pin.  Each

 * GPIO can trigger interrupts on either or both edges.

 *

 * GPIO interrupts can be fed to either of two IRQ lines; this is

 * intended to support multiple hosts.

 *

 * There are also two LED pins used sometimes as output-only GPIOs.

 */





static struct gpio_chip twl_gpiochip;

static int twl4030_gpio_irq_base;



/* genirq interfaces are not available to modules */

#ifdef MODULE

#define is_module()	true

#else

#define is_module()	false

#endif



/* GPIO_CTRL Fields */

#define MASK_GPIO_CTRL_GPIO0CD1		BIT(0)

#define MASK_GPIO_CTRL_GPIO1CD2		BIT(1)

#define MASK_GPIO_CTRL_GPIO_ON		BIT(2)



/* Mask for GPIO registers when aggregated into a 32-bit integer */

#define GPIO_32_MASK			0x0003ffff



/* Data structures */

static DEFINE_MUTEX(gpio_lock);



/* store usage of each GPIO. - each bit represents one GPIO */

static unsigned int gpio_usage_count;



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



/*

 * To configure TWL4030 GPIO module registers

 */

static inline int gpio_twl4030_write(u8 address, u8 data)

{

	return twl4030_i2c_write_u8(TWL4030_MODULE_GPIO, data, address);

}



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



/*

 * LED register offsets (use TWL4030_MODULE_{LED,PWMA,PWMB}))

 * PWMs A and B are dedicated to LEDs A and B, respectively.

 */



#define TWL4030_LED_LEDEN	0x0



/* LEDEN bits */

#define LEDEN_LEDAON		BIT(0)

#define LEDEN_LEDBON		BIT(1)

#define LEDEN_LEDAEXT		BIT(2)

#define LEDEN_LEDBEXT		BIT(3)

#define LEDEN_LEDAPWM		BIT(4)

#define LEDEN_LEDBPWM		BIT(5)

#define LEDEN_PWM_LENGTHA	BIT(6)

#define LEDEN_PWM_LENGTHB	BIT(7)



#define TWL4030_PWMx_PWMxON	0x0

#define TWL4030_PWMx_PWMxOFF	0x1



#define PWMxON_LENGTH		BIT(7)



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



/*

 * To read a TWL4030 GPIO module register

 */

static inline int gpio_twl4030_read(u8 address)

{

	u8 data;

	int ret = 0;



	ret = twl4030_i2c_read_u8(TWL4030_MODULE_GPIO, &data, address);

	return (ret < 0) ? ret : data;

}



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



static u8 cached_leden;		/* protected by gpio_lock */



/* The LED lines are open drain outputs ... a FET pulls to GND, so an

 * external pullup is needed.  We could also expose the integrated PWM

 * as a LED brightness control; we initialize it as "always on".

 */

static void twl4030_led_set_value(int led, int value)

{

	u8 mask = LEDEN_LEDAON | LEDEN_LEDAPWM;

	int status;



	if (led)

		mask <<= 1;



	mutex_lock(&gpio_lock);

	if (value)

		cached_leden &= ~mask;

	else

		cached_leden |= mask;

	status = twl4030_i2c_write_u8(TWL4030_MODULE_LED, cached_leden,

			TWL4030_LED_LEDEN);

	mutex_unlock(&gpio_lock);

}



static int twl4030_set_gpio_direction(int gpio, int is_input)

{

	u8 d_bnk = gpio >> 3;

	u8 d_msk = BIT(gpio & 0x7);

	u8 reg = 0;

	u8 base = REG_GPIODATADIR1 + d_bnk;

	int ret = 0;



	mutex_lock(&gpio_lock);

	ret = gpio_twl4030_read(base);

	if (ret >= 0) {

		if (is_input)

			reg = ret & ~d_msk;

		else

			reg = ret | d_msk;



		ret = gpio_twl4030_write(base, reg);

	}

	mutex_unlock(&gpio_lock);

	return ret;

}



static int twl4030_set_gpio_dataout(int gpio, int enable)

{

	u8 d_bnk = gpio >> 3;

	u8 d_msk = BIT(gpio & 0x7);

	u8 base = 0;



	if (enable)

		base = REG_SETGPIODATAOUT1 + d_bnk;

	else

		base = REG_CLEARGPIODATAOUT1 + d_bnk;



	return gpio_twl4030_write(base, d_msk);

}



static int twl4030_get_gpio_datain(int gpio)

{

	u8 d_bnk = gpio >> 3;

	u8 d_off = gpio & 0x7;

	u8 base = 0;

	int ret = 0;



	if (unlikely((gpio >= TWL4030_GPIO_MAX)

		|| !(gpio_usage_count & BIT(gpio))))

		return -EPERM;



	base = REG_GPIODATAIN1 + d_bnk;

	ret = gpio_twl4030_read(base);

	if (ret > 0)

		ret = (ret >> d_off) & 0x1;



	return ret;

}



/*

 * Configure debounce timing value for a GPIO pin on TWL4030

 */

int twl4030_set_gpio_debounce(int gpio, int enable)

{

	u8 d_bnk = gpio >> 3;

	u8 d_msk = BIT(gpio & 0x7);

	u8 reg = 0;

	u8 base = 0;

	int ret = 0;



	if (unlikely((gpio >= TWL4030_GPIO_MAX)

		|| !(gpio_usage_count & BIT(gpio))))

		return -EPERM;



	base = REG_GPIO_DEBEN1 + d_bnk;

	mutex_lock(&gpio_lock);

	ret = gpio_twl4030_read(base);

	if (ret >= 0) {

		if (enable)

			reg = ret | d_msk;

		else

			reg = ret & ~d_msk;



		ret = gpio_twl4030_write(base, reg);

	}

	mutex_unlock(&gpio_lock);

	return ret;

}

EXPORT_SYMBOL(twl4030_set_gpio_debounce);



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



static int twl_request(struct gpio_chip *chip, unsigned offset)

{

	int status = 0;



	mutex_lock(&gpio_lock);



	/* Support the two LED outputs as output-only GPIOs. */

	if (offset >= TWL4030_GPIO_MAX) {

		u8	ledclr_mask = LEDEN_LEDAON | LEDEN_LEDAEXT

				| LEDEN_LEDAPWM | LEDEN_PWM_LENGTHA;

		u8	module = TWL4030_MODULE_PWMA;



		offset -= TWL4030_GPIO_MAX;

		if (offset) {

			ledclr_mask <<= 1;

			module = TWL4030_MODULE_PWMB;

		}



		/* initialize PWM to always-drive */

		status = twl4030_i2c_write_u8(module, 0x7f,

				TWL4030_PWMx_PWMxOFF);

		if (status < 0)

			goto done;

		status = twl4030_i2c_write_u8(module, 0x7f,

				TWL4030_PWMx_PWMxON);

		if (status < 0)

			goto done;



		/* init LED to not-driven (high) */

		module = TWL4030_MODULE_LED;

		status = twl4030_i2c_read_u8(module, &cached_leden,

				TWL4030_LED_LEDEN);

		if (status < 0)

			goto done;

		cached_leden &= ~ledclr_mask;

		status = twl4030_i2c_write_u8(module, cached_leden,

				TWL4030_LED_LEDEN);

		if (status < 0)

			goto done;



		status = 0;

		goto done;

	}



	/* on first use, turn GPIO module "on" */

	if (!gpio_usage_count) {

		struct twl4030_gpio_platform_data *pdata;

		u8 value = MASK_GPIO_CTRL_GPIO_ON;



		/* optionally have the first two GPIOs switch vMMC1

		 * and vMMC2 power supplies based on card presence.

		 */

		pdata = chip->dev->platform_data;

		value |= pdata->mmc_cd & 0x03;



		status = gpio_twl4030_write(REG_GPIO_CTRL, value);

	}



	if (!status)

		gpio_usage_count |= (0x1 << offset);



done:

	mutex_unlock(&gpio_lock);

	return status;

}



static void twl_free(struct gpio_chip *chip, unsigned offset)

{

	if (offset >= TWL4030_GPIO_MAX) {

		twl4030_led_set_value(offset - TWL4030_GPIO_MAX, 1);

		return;

	}



	mutex_lock(&gpio_lock);



	gpio_usage_count &= ~BIT(offset);



	/* on last use, switch off GPIO module */

	if (!gpio_usage_count)

		gpio_twl4030_write(REG_GPIO_CTRL, 0x0);



	mutex_unlock(&gpio_lock);

}



static int twl_direction_in(struct gpio_chip *chip, unsigned offset)

{

	return (offset < TWL4030_GPIO_MAX)

		? twl4030_set_gpio_direction(offset, 1)

		: -EINVAL;

}



static int twl_get(struct gpio_chip *chip, unsigned offset)

{

	int status = 0;



	if (offset < TWL4030_GPIO_MAX)

		status = twl4030_get_gpio_datain(offset);

	else if (offset == TWL4030_GPIO_MAX)

		status = cached_leden & LEDEN_LEDAON;

	else

		status = cached_leden & LEDEN_LEDBON;

	return (status < 0) ? 0 : status;

}



static int twl_direction_out(struct gpio_chip *chip, unsigned offset, int value)

{

	if (offset < TWL4030_GPIO_MAX) {

		twl4030_set_gpio_dataout(offset, value);

		return twl4030_set_gpio_direction(offset, 0);

	} else {

		twl4030_led_set_value(offset - TWL4030_GPIO_MAX, value);

		return 0;

	}

}



static void twl_set(struct gpio_chip *chip, unsigned offset, int value)

{

	if (offset < TWL4030_GPIO_MAX)

		twl4030_set_gpio_dataout(offset, value);

	else

		twl4030_led_set_value(offset - TWL4030_GPIO_MAX, value);

}



static int twl_to_irq(struct gpio_chip *chip, unsigned offset)

{

	return (twl4030_gpio_irq_base && (offset < TWL4030_GPIO_MAX))

		? (twl4030_gpio_irq_base + offset)

		: -EINVAL;

}



static struct gpio_chip twl_gpiochip = {

	.label			= "twl4030",

	.owner			= THIS_MODULE,

	.request		= twl_request,

	.free			= twl_free,

	.direction_input	= twl_direction_in,

	.get			= twl_get,

	.direction_output	= twl_direction_out,

	.set			= twl_set,

	.to_irq			= twl_to_irq,

	.can_sleep		= 1,

};



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



static int __devinit gpio_twl4030_pulls(u32 ups, u32 downs)

{

	u8		message[6];

	unsigned	i, gpio_bit;



	/* For most pins, a pulldown was enabled by default.

	 * We should have data that's specific to this board.

	 */

	for (gpio_bit = 1, i = 1; i < 6; i++) {

		u8		bit_mask;

		unsigned	j;



		for (bit_mask = 0, j = 0; j < 8; j += 2, gpio_bit <<= 1) {

			if (ups & gpio_bit)

				bit_mask |= 1 << (j + 1);

			else if (downs & gpio_bit)

				bit_mask |= 1 << (j + 0);

		}

		message[i] = bit_mask;

	}



	return twl4030_i2c_write(TWL4030_MODULE_GPIO, message,

				REG_GPIOPUPDCTR1, 5);

}



static int gpio_twl4030_remove(struct platform_device *pdev);



static int __devinit gpio_twl4030_probe(struct platform_device *pdev)

{

	struct twl4030_gpio_platform_data *pdata = pdev->dev.platform_data;

	int ret;



	/* maybe setup IRQs */

	if (pdata->irq_base) {

		if (is_module()) {

			dev_err(&pdev->dev,

				"can't dispatch IRQs from modules\n");

			goto no_irqs;

		}

		ret = twl4030_sih_setup(TWL4030_MODULE_GPIO);

		if (ret < 0)

			return ret;

		WARN_ON(ret != pdata->irq_base);

		twl4030_gpio_irq_base = ret;

	}



no_irqs:

	/*

	 * NOTE:  boards may waste power if they don't set pullups

	 * and pulldowns correctly ... default for non-ULPI pins is

	 * pulldown, and some other pins may have external pullups

	 * or pulldowns.  Careful!

	 */

	ret = gpio_twl4030_pulls(pdata->pullups, pdata->pulldowns);

	if (ret)

		dev_dbg(&pdev->dev, "pullups %.05x %.05x --> %d\n",

				pdata->pullups, pdata->pulldowns,

				ret);



	twl_gpiochip.base = pdata->gpio_base;

	twl_gpiochip.ngpio = TWL4030_GPIO_MAX;

	twl_gpiochip.dev = &pdev->dev;



	/* NOTE: we assume VIBRA_CTL.VIBRA_EN, in MODULE_AUDIO_VOICE,

	 * is (still) clear if use_leds is set.

	 */

	if (pdata->use_leds)

		twl_gpiochip.ngpio += 2;



	ret = gpiochip_add(&twl_gpiochip);

	if (ret < 0) {

		dev_err(&pdev->dev,

				"could not register gpiochip, %d\n",

				ret);

		twl_gpiochip.ngpio = 0;

		gpio_twl4030_remove(pdev);

	} else if (pdata->setup) {

		int status;



		status = pdata->setup(&pdev->dev,

				pdata->gpio_base, TWL4030_GPIO_MAX);

		if (status)

			dev_dbg(&pdev->dev, "setup --> %d\n", status);

	}



	return ret;

}



static int __devexit gpio_twl4030_remove(struct platform_device *pdev)

{

	struct twl4030_gpio_platform_data *pdata = pdev->dev.platform_data;

	int status;



	if (pdata->teardown) {

		status = pdata->teardown(&pdev->dev,

				pdata->gpio_base, TWL4030_GPIO_MAX);

		if (status) {

			dev_dbg(&pdev->dev, "teardown --> %d\n", status);

			return status;

		}

	}



	status = gpiochip_remove(&twl_gpiochip);

	if (status < 0)

		return status;



	if (is_module())

		return 0;



	/* REVISIT no support yet for deregistering all the IRQs */

	WARN_ON(1);

	return -EIO;

}



/* Note:  this hardware lives inside an I2C-based multi-function device. */

MODULE_ALIAS("platform:twl4030_gpio");



static struct platform_driver gpio_twl4030_driver = {

	.driver.name	= "twl4030_gpio",

	.driver.owner	= THIS_MODULE,

	.probe		= gpio_twl4030_probe,

	.remove		= __devexit_p(gpio_twl4030_remove),

};



static int __init gpio_twl4030_init(void)

{

	return platform_driver_register(&gpio_twl4030_driver);

}

subsys_initcall(gpio_twl4030_init);



static void __exit gpio_twl4030_exit(void)

{

	platform_driver_unregister(&gpio_twl4030_driver);

}

module_exit(gpio_twl4030_exit);



MODULE_AUTHOR("Texas Instruments, Inc.");

MODULE_DESCRIPTION("GPIO interface for TWL4030");

MODULE_LICENSE("GPL");

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