317 lines
7.3 KiB
C
317 lines
7.3 KiB
C
/*
|
|
* Support for viafb GPIO ports.
|
|
*
|
|
* Copyright 2009 Jonathan Corbet <corbet@lwn.net>
|
|
* Distributable under version 2 of the GNU General Public License.
|
|
*/
|
|
|
|
#include <linux/spinlock.h>
|
|
#include <linux/gpio.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/via-core.h>
|
|
#include <linux/via-gpio.h>
|
|
#include <linux/export.h>
|
|
|
|
/*
|
|
* The ports we know about. Note that the port-25 gpios are not
|
|
* mentioned in the datasheet.
|
|
*/
|
|
|
|
struct viafb_gpio {
|
|
char *vg_name; /* Data sheet name */
|
|
u16 vg_io_port;
|
|
u8 vg_port_index;
|
|
int vg_mask_shift;
|
|
};
|
|
|
|
static struct viafb_gpio viafb_all_gpios[] = {
|
|
{
|
|
.vg_name = "VGPIO0", /* Guess - not in datasheet */
|
|
.vg_io_port = VIASR,
|
|
.vg_port_index = 0x25,
|
|
.vg_mask_shift = 1
|
|
},
|
|
{
|
|
.vg_name = "VGPIO1",
|
|
.vg_io_port = VIASR,
|
|
.vg_port_index = 0x25,
|
|
.vg_mask_shift = 0
|
|
},
|
|
{
|
|
.vg_name = "VGPIO2", /* aka DISPCLKI0 */
|
|
.vg_io_port = VIASR,
|
|
.vg_port_index = 0x2c,
|
|
.vg_mask_shift = 1
|
|
},
|
|
{
|
|
.vg_name = "VGPIO3", /* aka DISPCLKO0 */
|
|
.vg_io_port = VIASR,
|
|
.vg_port_index = 0x2c,
|
|
.vg_mask_shift = 0
|
|
},
|
|
{
|
|
.vg_name = "VGPIO4", /* DISPCLKI1 */
|
|
.vg_io_port = VIASR,
|
|
.vg_port_index = 0x3d,
|
|
.vg_mask_shift = 1
|
|
},
|
|
{
|
|
.vg_name = "VGPIO5", /* DISPCLKO1 */
|
|
.vg_io_port = VIASR,
|
|
.vg_port_index = 0x3d,
|
|
.vg_mask_shift = 0
|
|
},
|
|
};
|
|
|
|
#define VIAFB_NUM_GPIOS ARRAY_SIZE(viafb_all_gpios)
|
|
|
|
/*
|
|
* This structure controls the active GPIOs, which may be a subset
|
|
* of those which are known.
|
|
*/
|
|
|
|
struct viafb_gpio_cfg {
|
|
struct gpio_chip gpio_chip;
|
|
struct viafb_dev *vdev;
|
|
struct viafb_gpio *active_gpios[VIAFB_NUM_GPIOS];
|
|
const char *gpio_names[VIAFB_NUM_GPIOS];
|
|
};
|
|
|
|
/*
|
|
* GPIO access functions
|
|
*/
|
|
static void via_gpio_set(struct gpio_chip *chip, unsigned int nr,
|
|
int value)
|
|
{
|
|
struct viafb_gpio_cfg *cfg = container_of(chip,
|
|
struct viafb_gpio_cfg,
|
|
gpio_chip);
|
|
u8 reg;
|
|
struct viafb_gpio *gpio;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&cfg->vdev->reg_lock, flags);
|
|
gpio = cfg->active_gpios[nr];
|
|
reg = via_read_reg(VIASR, gpio->vg_port_index);
|
|
reg |= 0x40 << gpio->vg_mask_shift; /* output enable */
|
|
if (value)
|
|
reg |= 0x10 << gpio->vg_mask_shift;
|
|
else
|
|
reg &= ~(0x10 << gpio->vg_mask_shift);
|
|
via_write_reg(VIASR, gpio->vg_port_index, reg);
|
|
spin_unlock_irqrestore(&cfg->vdev->reg_lock, flags);
|
|
}
|
|
|
|
static int via_gpio_dir_out(struct gpio_chip *chip, unsigned int nr,
|
|
int value)
|
|
{
|
|
via_gpio_set(chip, nr, value);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Set the input direction. I'm not sure this is right; we should
|
|
* be able to do input without disabling output.
|
|
*/
|
|
static int via_gpio_dir_input(struct gpio_chip *chip, unsigned int nr)
|
|
{
|
|
struct viafb_gpio_cfg *cfg = container_of(chip,
|
|
struct viafb_gpio_cfg,
|
|
gpio_chip);
|
|
struct viafb_gpio *gpio;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&cfg->vdev->reg_lock, flags);
|
|
gpio = cfg->active_gpios[nr];
|
|
via_write_reg_mask(VIASR, gpio->vg_port_index, 0,
|
|
0x40 << gpio->vg_mask_shift);
|
|
spin_unlock_irqrestore(&cfg->vdev->reg_lock, flags);
|
|
return 0;
|
|
}
|
|
|
|
static int via_gpio_get(struct gpio_chip *chip, unsigned int nr)
|
|
{
|
|
struct viafb_gpio_cfg *cfg = container_of(chip,
|
|
struct viafb_gpio_cfg,
|
|
gpio_chip);
|
|
u8 reg;
|
|
struct viafb_gpio *gpio;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&cfg->vdev->reg_lock, flags);
|
|
gpio = cfg->active_gpios[nr];
|
|
reg = via_read_reg(VIASR, gpio->vg_port_index);
|
|
spin_unlock_irqrestore(&cfg->vdev->reg_lock, flags);
|
|
return reg & (0x04 << gpio->vg_mask_shift);
|
|
}
|
|
|
|
|
|
static struct viafb_gpio_cfg viafb_gpio_config = {
|
|
.gpio_chip = {
|
|
.label = "VIAFB onboard GPIO",
|
|
.owner = THIS_MODULE,
|
|
.direction_output = via_gpio_dir_out,
|
|
.set = via_gpio_set,
|
|
.direction_input = via_gpio_dir_input,
|
|
.get = via_gpio_get,
|
|
.base = -1,
|
|
.ngpio = 0,
|
|
.can_sleep = 0
|
|
}
|
|
};
|
|
|
|
/*
|
|
* Manage the software enable bit.
|
|
*/
|
|
static void viafb_gpio_enable(struct viafb_gpio *gpio)
|
|
{
|
|
via_write_reg_mask(VIASR, gpio->vg_port_index, 0x02, 0x02);
|
|
}
|
|
|
|
static void viafb_gpio_disable(struct viafb_gpio *gpio)
|
|
{
|
|
via_write_reg_mask(VIASR, gpio->vg_port_index, 0, 0x02);
|
|
}
|
|
|
|
#ifdef CONFIG_PM
|
|
|
|
static int viafb_gpio_suspend(void *private)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static int viafb_gpio_resume(void *private)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < viafb_gpio_config.gpio_chip.ngpio; i += 2)
|
|
viafb_gpio_enable(viafb_gpio_config.active_gpios[i]);
|
|
return 0;
|
|
}
|
|
|
|
static struct viafb_pm_hooks viafb_gpio_pm_hooks = {
|
|
.suspend = viafb_gpio_suspend,
|
|
.resume = viafb_gpio_resume
|
|
};
|
|
#endif /* CONFIG_PM */
|
|
|
|
/*
|
|
* Look up a specific gpio and return the number it was assigned.
|
|
*/
|
|
int viafb_gpio_lookup(const char *name)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < viafb_gpio_config.gpio_chip.ngpio; i++)
|
|
if (!strcmp(name, viafb_gpio_config.active_gpios[i]->vg_name))
|
|
return viafb_gpio_config.gpio_chip.base + i;
|
|
return -1;
|
|
}
|
|
EXPORT_SYMBOL_GPL(viafb_gpio_lookup);
|
|
|
|
/*
|
|
* Platform device stuff.
|
|
*/
|
|
static int viafb_gpio_probe(struct platform_device *platdev)
|
|
{
|
|
struct viafb_dev *vdev = platdev->dev.platform_data;
|
|
struct via_port_cfg *port_cfg = vdev->port_cfg;
|
|
int i, ngpio = 0, ret;
|
|
struct viafb_gpio *gpio;
|
|
unsigned long flags;
|
|
|
|
/*
|
|
* Set up entries for all GPIOs which have been configured to
|
|
* operate as such (as opposed to as i2c ports).
|
|
*/
|
|
for (i = 0; i < VIAFB_NUM_PORTS; i++) {
|
|
if (port_cfg[i].mode != VIA_MODE_GPIO)
|
|
continue;
|
|
for (gpio = viafb_all_gpios;
|
|
gpio < viafb_all_gpios + VIAFB_NUM_GPIOS; gpio++)
|
|
if (gpio->vg_port_index == port_cfg[i].ioport_index) {
|
|
viafb_gpio_config.active_gpios[ngpio] = gpio;
|
|
viafb_gpio_config.gpio_names[ngpio] =
|
|
gpio->vg_name;
|
|
ngpio++;
|
|
}
|
|
}
|
|
viafb_gpio_config.gpio_chip.ngpio = ngpio;
|
|
viafb_gpio_config.gpio_chip.names = viafb_gpio_config.gpio_names;
|
|
viafb_gpio_config.vdev = vdev;
|
|
if (ngpio == 0) {
|
|
printk(KERN_INFO "viafb: no GPIOs configured\n");
|
|
return 0;
|
|
}
|
|
/*
|
|
* Enable the ports. They come in pairs, with a single
|
|
* enable bit for both.
|
|
*/
|
|
spin_lock_irqsave(&viafb_gpio_config.vdev->reg_lock, flags);
|
|
for (i = 0; i < ngpio; i += 2)
|
|
viafb_gpio_enable(viafb_gpio_config.active_gpios[i]);
|
|
spin_unlock_irqrestore(&viafb_gpio_config.vdev->reg_lock, flags);
|
|
/*
|
|
* Get registered.
|
|
*/
|
|
viafb_gpio_config.gpio_chip.base = -1; /* Dynamic */
|
|
ret = gpiochip_add(&viafb_gpio_config.gpio_chip);
|
|
if (ret) {
|
|
printk(KERN_ERR "viafb: failed to add gpios (%d)\n", ret);
|
|
viafb_gpio_config.gpio_chip.ngpio = 0;
|
|
}
|
|
#ifdef CONFIG_PM
|
|
viafb_pm_register(&viafb_gpio_pm_hooks);
|
|
#endif
|
|
return ret;
|
|
}
|
|
|
|
|
|
static int viafb_gpio_remove(struct platform_device *platdev)
|
|
{
|
|
unsigned long flags;
|
|
int ret = 0, i;
|
|
|
|
#ifdef CONFIG_PM
|
|
viafb_pm_unregister(&viafb_gpio_pm_hooks);
|
|
#endif
|
|
|
|
/*
|
|
* Get unregistered.
|
|
*/
|
|
if (viafb_gpio_config.gpio_chip.ngpio > 0) {
|
|
ret = gpiochip_remove(&viafb_gpio_config.gpio_chip);
|
|
if (ret) { /* Somebody still using it? */
|
|
printk(KERN_ERR "Viafb: GPIO remove failed\n");
|
|
return ret;
|
|
}
|
|
}
|
|
/*
|
|
* Disable the ports.
|
|
*/
|
|
spin_lock_irqsave(&viafb_gpio_config.vdev->reg_lock, flags);
|
|
for (i = 0; i < viafb_gpio_config.gpio_chip.ngpio; i += 2)
|
|
viafb_gpio_disable(viafb_gpio_config.active_gpios[i]);
|
|
viafb_gpio_config.gpio_chip.ngpio = 0;
|
|
spin_unlock_irqrestore(&viafb_gpio_config.vdev->reg_lock, flags);
|
|
return ret;
|
|
}
|
|
|
|
static struct platform_driver via_gpio_driver = {
|
|
.driver = {
|
|
.name = "viafb-gpio",
|
|
},
|
|
.probe = viafb_gpio_probe,
|
|
.remove = viafb_gpio_remove,
|
|
};
|
|
|
|
int viafb_gpio_init(void)
|
|
{
|
|
return platform_driver_register(&via_gpio_driver);
|
|
}
|
|
|
|
void viafb_gpio_exit(void)
|
|
{
|
|
platform_driver_unregister(&via_gpio_driver);
|
|
}
|