OpenE2K/linux
6
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity
af5f88c877
linux/drivers/gpio/twl4030-gpio.c
David Brownell cabb3fc4bd twl4030-gpio: cleanup debounce 
Provide a static debounce configuration mechanism for twl4030 GPIOs,
replacing the previous dynamic one.  The single user of that mechanism was
for MMC card detect debouncing.

Boards can provide a bitmask saying which GPIOs to debounce (30 msec).
It's always enabled for pins with the MMC card-detect/VMMCx link active,
so most boards won't need to set the debounce mask.

This is a net code shrink, including runtime footprint.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06 15:59:25 -08:00

514 lines
12 KiB
C
Raw Blame History

/*
* 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;
}
/*----------------------------------------------------------------------*/
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 __devinit gpio_twl4030_debounce(u32 debounce, u8 mmc_cd)
{
u8 message[4];
/* 30 msec of debouncing is always used for MMC card detect,
* and is optional for everything else.
*/
message[1] = (debounce & 0xff) | (mmc_cd & 0x03);
debounce >>= 8;
message[2] = (debounce & 0xff);
debounce >>= 8;
message[3] = (debounce & 0x03);
return twl4030_i2c_write(TWL4030_MODULE_GPIO, message,
REG_GPIO_DEBEN1, 3);
}
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);
ret = gpio_twl4030_debounce(pdata->debounce, pdata->mmc_cd);
if (ret)
dev_dbg(&pdev->dev, "debounce %.03x %.01x --> %d\n",
pdata->debounce, pdata->mmc_cd,
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");
Reference in New Issue View Git Blame Copy Permalink