![David Brownell](/assets/img/avatar_default.png)
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: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Samuel Ortiz <sameo@openedhand.com>
522 lines
12 KiB
C
522 lines
12 KiB
C
/*
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* twl4030_gpio.c -- access to GPIOs on TWL4030/TPS659x0 chips
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*
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* Copyright (C) 2006-2007 Texas Instruments, Inc.
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* Copyright (C) 2006 MontaVista Software, Inc.
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*
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* Code re-arranged and cleaned up by:
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* Syed Mohammed Khasim <x0khasim@ti.com>
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*
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* Initial Code:
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* Andy Lowe / Nishanth Menon
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/kthread.h>
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#include <linux/irq.h>
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#include <linux/gpio.h>
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#include <linux/platform_device.h>
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#include <linux/slab.h>
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#include <linux/i2c/twl4030.h>
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/*
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* The GPIO "subchip" supports 18 GPIOs which can be configured as
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* inputs or outputs, with pullups or pulldowns on each pin. Each
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* GPIO can trigger interrupts on either or both edges.
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*
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* GPIO interrupts can be fed to either of two IRQ lines; this is
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* intended to support multiple hosts.
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*
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* There are also two LED pins used sometimes as output-only GPIOs.
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*/
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static struct gpio_chip twl_gpiochip;
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static int twl4030_gpio_irq_base;
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/* genirq interfaces are not available to modules */
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#ifdef MODULE
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#define is_module() true
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#else
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#define is_module() false
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#endif
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/* GPIO_CTRL Fields */
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#define MASK_GPIO_CTRL_GPIO0CD1 BIT(0)
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#define MASK_GPIO_CTRL_GPIO1CD2 BIT(1)
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#define MASK_GPIO_CTRL_GPIO_ON BIT(2)
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/* Mask for GPIO registers when aggregated into a 32-bit integer */
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#define GPIO_32_MASK 0x0003ffff
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/* Data structures */
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static DEFINE_MUTEX(gpio_lock);
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/* store usage of each GPIO. - each bit represents one GPIO */
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static unsigned int gpio_usage_count;
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/*----------------------------------------------------------------------*/
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/*
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* To configure TWL4030 GPIO module registers
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*/
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static inline int gpio_twl4030_write(u8 address, u8 data)
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{
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return twl4030_i2c_write_u8(TWL4030_MODULE_GPIO, data, address);
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}
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/*----------------------------------------------------------------------*/
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/*
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* LED register offsets (use TWL4030_MODULE_{LED,PWMA,PWMB}))
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* PWMs A and B are dedicated to LEDs A and B, respectively.
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*/
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#define TWL4030_LED_LEDEN 0x0
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/* LEDEN bits */
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#define LEDEN_LEDAON BIT(0)
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#define LEDEN_LEDBON BIT(1)
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#define LEDEN_LEDAEXT BIT(2)
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#define LEDEN_LEDBEXT BIT(3)
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#define LEDEN_LEDAPWM BIT(4)
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#define LEDEN_LEDBPWM BIT(5)
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#define LEDEN_PWM_LENGTHA BIT(6)
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#define LEDEN_PWM_LENGTHB BIT(7)
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#define TWL4030_PWMx_PWMxON 0x0
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#define TWL4030_PWMx_PWMxOFF 0x1
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#define PWMxON_LENGTH BIT(7)
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/*----------------------------------------------------------------------*/
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/*
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* To read a TWL4030 GPIO module register
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*/
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static inline int gpio_twl4030_read(u8 address)
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{
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u8 data;
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int ret = 0;
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ret = twl4030_i2c_read_u8(TWL4030_MODULE_GPIO, &data, address);
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return (ret < 0) ? ret : data;
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}
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/*----------------------------------------------------------------------*/
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static u8 cached_leden; /* protected by gpio_lock */
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/* The LED lines are open drain outputs ... a FET pulls to GND, so an
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* external pullup is needed. We could also expose the integrated PWM
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* as a LED brightness control; we initialize it as "always on".
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*/
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static void twl4030_led_set_value(int led, int value)
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{
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u8 mask = LEDEN_LEDAON | LEDEN_LEDAPWM;
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int status;
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if (led)
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mask <<= 1;
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mutex_lock(&gpio_lock);
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if (value)
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cached_leden &= ~mask;
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else
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cached_leden |= mask;
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status = twl4030_i2c_write_u8(TWL4030_MODULE_LED, cached_leden,
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TWL4030_LED_LEDEN);
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mutex_unlock(&gpio_lock);
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}
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static int twl4030_set_gpio_direction(int gpio, int is_input)
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{
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u8 d_bnk = gpio >> 3;
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u8 d_msk = BIT(gpio & 0x7);
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u8 reg = 0;
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u8 base = REG_GPIODATADIR1 + d_bnk;
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int ret = 0;
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mutex_lock(&gpio_lock);
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ret = gpio_twl4030_read(base);
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if (ret >= 0) {
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if (is_input)
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reg = ret & ~d_msk;
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else
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reg = ret | d_msk;
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ret = gpio_twl4030_write(base, reg);
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}
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mutex_unlock(&gpio_lock);
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return ret;
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}
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static int twl4030_set_gpio_dataout(int gpio, int enable)
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{
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u8 d_bnk = gpio >> 3;
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u8 d_msk = BIT(gpio & 0x7);
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u8 base = 0;
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if (enable)
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base = REG_SETGPIODATAOUT1 + d_bnk;
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else
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base = REG_CLEARGPIODATAOUT1 + d_bnk;
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return gpio_twl4030_write(base, d_msk);
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}
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static int twl4030_get_gpio_datain(int gpio)
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{
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u8 d_bnk = gpio >> 3;
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u8 d_off = gpio & 0x7;
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u8 base = 0;
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int ret = 0;
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if (unlikely((gpio >= TWL4030_GPIO_MAX)
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|| !(gpio_usage_count & BIT(gpio))))
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return -EPERM;
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base = REG_GPIODATAIN1 + d_bnk;
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ret = gpio_twl4030_read(base);
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if (ret > 0)
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ret = (ret >> d_off) & 0x1;
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return ret;
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}
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/*
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* Configure debounce timing value for a GPIO pin on TWL4030
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*/
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int twl4030_set_gpio_debounce(int gpio, int enable)
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{
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u8 d_bnk = gpio >> 3;
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u8 d_msk = BIT(gpio & 0x7);
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u8 reg = 0;
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u8 base = 0;
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int ret = 0;
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if (unlikely((gpio >= TWL4030_GPIO_MAX)
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|| !(gpio_usage_count & BIT(gpio))))
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return -EPERM;
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base = REG_GPIO_DEBEN1 + d_bnk;
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mutex_lock(&gpio_lock);
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ret = gpio_twl4030_read(base);
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if (ret >= 0) {
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if (enable)
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reg = ret | d_msk;
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else
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reg = ret & ~d_msk;
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ret = gpio_twl4030_write(base, reg);
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}
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mutex_unlock(&gpio_lock);
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return ret;
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}
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EXPORT_SYMBOL(twl4030_set_gpio_debounce);
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/*----------------------------------------------------------------------*/
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static int twl_request(struct gpio_chip *chip, unsigned offset)
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{
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int status = 0;
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mutex_lock(&gpio_lock);
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/* Support the two LED outputs as output-only GPIOs. */
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if (offset >= TWL4030_GPIO_MAX) {
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u8 ledclr_mask = LEDEN_LEDAON | LEDEN_LEDAEXT
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| LEDEN_LEDAPWM | LEDEN_PWM_LENGTHA;
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u8 module = TWL4030_MODULE_PWMA;
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offset -= TWL4030_GPIO_MAX;
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if (offset) {
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ledclr_mask <<= 1;
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module = TWL4030_MODULE_PWMB;
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}
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/* initialize PWM to always-drive */
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status = twl4030_i2c_write_u8(module, 0x7f,
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TWL4030_PWMx_PWMxOFF);
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if (status < 0)
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goto done;
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status = twl4030_i2c_write_u8(module, 0x7f,
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TWL4030_PWMx_PWMxON);
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if (status < 0)
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goto done;
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/* init LED to not-driven (high) */
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module = TWL4030_MODULE_LED;
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status = twl4030_i2c_read_u8(module, &cached_leden,
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TWL4030_LED_LEDEN);
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if (status < 0)
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goto done;
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cached_leden &= ~ledclr_mask;
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status = twl4030_i2c_write_u8(module, cached_leden,
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TWL4030_LED_LEDEN);
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if (status < 0)
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goto done;
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status = 0;
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goto done;
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}
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/* on first use, turn GPIO module "on" */
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if (!gpio_usage_count) {
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struct twl4030_gpio_platform_data *pdata;
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u8 value = MASK_GPIO_CTRL_GPIO_ON;
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/* optionally have the first two GPIOs switch vMMC1
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* and vMMC2 power supplies based on card presence.
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*/
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pdata = chip->dev->platform_data;
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value |= pdata->mmc_cd & 0x03;
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status = gpio_twl4030_write(REG_GPIO_CTRL, value);
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}
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if (!status)
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gpio_usage_count |= (0x1 << offset);
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done:
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mutex_unlock(&gpio_lock);
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return status;
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}
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static void twl_free(struct gpio_chip *chip, unsigned offset)
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{
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if (offset >= TWL4030_GPIO_MAX) {
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twl4030_led_set_value(offset - TWL4030_GPIO_MAX, 1);
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return;
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}
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mutex_lock(&gpio_lock);
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gpio_usage_count &= ~BIT(offset);
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/* on last use, switch off GPIO module */
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if (!gpio_usage_count)
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gpio_twl4030_write(REG_GPIO_CTRL, 0x0);
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mutex_unlock(&gpio_lock);
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}
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static int twl_direction_in(struct gpio_chip *chip, unsigned offset)
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{
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return (offset < TWL4030_GPIO_MAX)
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? twl4030_set_gpio_direction(offset, 1)
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: -EINVAL;
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}
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static int twl_get(struct gpio_chip *chip, unsigned offset)
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{
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int status = 0;
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if (offset < TWL4030_GPIO_MAX)
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status = twl4030_get_gpio_datain(offset);
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else if (offset == TWL4030_GPIO_MAX)
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status = cached_leden & LEDEN_LEDAON;
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else
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status = cached_leden & LEDEN_LEDBON;
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return (status < 0) ? 0 : status;
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}
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static int twl_direction_out(struct gpio_chip *chip, unsigned offset, int value)
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{
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if (offset < TWL4030_GPIO_MAX) {
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twl4030_set_gpio_dataout(offset, value);
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return twl4030_set_gpio_direction(offset, 0);
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} else {
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twl4030_led_set_value(offset - TWL4030_GPIO_MAX, value);
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return 0;
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}
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}
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static void twl_set(struct gpio_chip *chip, unsigned offset, int value)
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{
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if (offset < TWL4030_GPIO_MAX)
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twl4030_set_gpio_dataout(offset, value);
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else
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twl4030_led_set_value(offset - TWL4030_GPIO_MAX, value);
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}
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static int twl_to_irq(struct gpio_chip *chip, unsigned offset)
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{
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return (twl4030_gpio_irq_base && (offset < TWL4030_GPIO_MAX))
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? (twl4030_gpio_irq_base + offset)
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: -EINVAL;
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}
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static struct gpio_chip twl_gpiochip = {
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.label = "twl4030",
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.owner = THIS_MODULE,
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.request = twl_request,
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.free = twl_free,
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.direction_input = twl_direction_in,
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.get = twl_get,
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.direction_output = twl_direction_out,
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.set = twl_set,
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.to_irq = twl_to_irq,
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.can_sleep = 1,
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};
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/*----------------------------------------------------------------------*/
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static int __devinit gpio_twl4030_pulls(u32 ups, u32 downs)
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{
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u8 message[6];
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unsigned i, gpio_bit;
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/* For most pins, a pulldown was enabled by default.
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* We should have data that's specific to this board.
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*/
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for (gpio_bit = 1, i = 1; i < 6; i++) {
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u8 bit_mask;
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unsigned j;
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for (bit_mask = 0, j = 0; j < 8; j += 2, gpio_bit <<= 1) {
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if (ups & gpio_bit)
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bit_mask |= 1 << (j + 1);
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else if (downs & gpio_bit)
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bit_mask |= 1 << (j + 0);
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}
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message[i] = bit_mask;
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}
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return twl4030_i2c_write(TWL4030_MODULE_GPIO, message,
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REG_GPIOPUPDCTR1, 5);
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}
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static int gpio_twl4030_remove(struct platform_device *pdev);
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static int __devinit gpio_twl4030_probe(struct platform_device *pdev)
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{
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struct twl4030_gpio_platform_data *pdata = pdev->dev.platform_data;
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int ret;
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/* maybe setup IRQs */
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if (pdata->irq_base) {
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if (is_module()) {
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dev_err(&pdev->dev,
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"can't dispatch IRQs from modules\n");
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goto no_irqs;
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}
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ret = twl4030_sih_setup(TWL4030_MODULE_GPIO);
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if (ret < 0)
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return ret;
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WARN_ON(ret != pdata->irq_base);
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twl4030_gpio_irq_base = ret;
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}
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no_irqs:
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/*
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* NOTE: boards may waste power if they don't set pullups
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* and pulldowns correctly ... default for non-ULPI pins is
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* pulldown, and some other pins may have external pullups
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* or pulldowns. Careful!
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*/
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ret = gpio_twl4030_pulls(pdata->pullups, pdata->pulldowns);
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if (ret)
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dev_dbg(&pdev->dev, "pullups %.05x %.05x --> %d\n",
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pdata->pullups, pdata->pulldowns,
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ret);
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twl_gpiochip.base = pdata->gpio_base;
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twl_gpiochip.ngpio = TWL4030_GPIO_MAX;
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twl_gpiochip.dev = &pdev->dev;
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/* NOTE: we assume VIBRA_CTL.VIBRA_EN, in MODULE_AUDIO_VOICE,
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* is (still) clear if use_leds is set.
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*/
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if (pdata->use_leds)
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twl_gpiochip.ngpio += 2;
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ret = gpiochip_add(&twl_gpiochip);
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if (ret < 0) {
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dev_err(&pdev->dev,
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"could not register gpiochip, %d\n",
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ret);
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twl_gpiochip.ngpio = 0;
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gpio_twl4030_remove(pdev);
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} else if (pdata->setup) {
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int status;
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status = pdata->setup(&pdev->dev,
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pdata->gpio_base, TWL4030_GPIO_MAX);
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if (status)
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dev_dbg(&pdev->dev, "setup --> %d\n", status);
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}
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return ret;
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}
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static int __devexit gpio_twl4030_remove(struct platform_device *pdev)
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{
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struct twl4030_gpio_platform_data *pdata = pdev->dev.platform_data;
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int status;
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if (pdata->teardown) {
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status = pdata->teardown(&pdev->dev,
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pdata->gpio_base, TWL4030_GPIO_MAX);
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if (status) {
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dev_dbg(&pdev->dev, "teardown --> %d\n", status);
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return status;
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}
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}
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status = gpiochip_remove(&twl_gpiochip);
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if (status < 0)
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return status;
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if (is_module())
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return 0;
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/* REVISIT no support yet for deregistering all the IRQs */
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WARN_ON(1);
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return -EIO;
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}
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/* Note: this hardware lives inside an I2C-based multi-function device. */
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MODULE_ALIAS("platform:twl4030_gpio");
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static struct platform_driver gpio_twl4030_driver = {
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.driver.name = "twl4030_gpio",
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.driver.owner = THIS_MODULE,
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.probe = gpio_twl4030_probe,
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.remove = __devexit_p(gpio_twl4030_remove),
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};
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static int __init gpio_twl4030_init(void)
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{
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return platform_driver_register(&gpio_twl4030_driver);
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}
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subsys_initcall(gpio_twl4030_init);
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|
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static void __exit gpio_twl4030_exit(void)
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|
{
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platform_driver_unregister(&gpio_twl4030_driver);
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}
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module_exit(gpio_twl4030_exit);
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|
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MODULE_AUTHOR("Texas Instruments, Inc.");
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|
MODULE_DESCRIPTION("GPIO interface for TWL4030");
|
|
MODULE_LICENSE("GPL");
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