Commit 7e0de022 authored by Jonathan Corbet's avatar Jonathan Corbet

viafb: add a driver for GPIO lines

This is a simple gpiolib driver giving access to the GPIO lines in the
VIA framebuffer system.  A simple mechanism exists for switching lines
between GPIO and I2C, but it's only compile-time for now.

Cc: ScottFang@viatech.com.cn
Cc: JosephChan@via.com.tw
Cc: Harald Welte <laforge@gnumonks.org>
Acked-by: default avatarFlorian Tobias Schandinat <FlorianSchandinat@gmx.de>
Signed-off-by: default avatarJonathan Corbet <corbet@lwn.net>
parent 24b4d82e
......@@ -1511,6 +1511,7 @@ config FB_VIA
select FB_CFB_IMAGEBLIT
select I2C_ALGOBIT
select I2C
select GPIOLIB
help
This is the frame buffer device driver for Graphics chips of VIA
UniChrome (Pro) Family (CLE266,PM800/CN400,P4M800CE/P4M800Pro/
......@@ -1520,6 +1521,7 @@ config FB_VIA
To compile this driver as a module, choose M here: the
module will be called viafb.
config FB_NEOMAGIC
tristate "NeoMagic display support"
depends on FB && PCI
......
......@@ -4,4 +4,7 @@
obj-$(CONFIG_FB_VIA) += viafb.o
viafb-y :=viafbdev.o hw.o via_i2c.o dvi.o lcd.o ioctl.o accel.o via_utility.o vt1636.o global.o tblDPASetting.o viamode.o tbl1636.o via-core.o
viafb-y :=viafbdev.o hw.o via_i2c.o dvi.o lcd.o ioctl.o accel.o \
via_utility.o vt1636.o global.o tblDPASetting.o viamode.o tbl1636.o \
via-core.o via-gpio.o
......@@ -9,6 +9,7 @@
*/
#include "via-core.h"
#include "via_i2c.h"
#include "via-gpio.h"
#include "global.h"
#include <linux/module.h>
......@@ -221,6 +222,11 @@ static int __devinit via_pci_probe(struct pci_dev *pdev,
ret = via_fb_pci_probe(&global_dev);
if (ret)
goto out_i2c;
/*
* Create the GPIOs. We continue whether or not this succeeds;
* the framebuffer might be useful even without GPIO ports.
*/
ret = viafb_create_gpios(&global_dev, adap_configs);
return 0;
out_i2c:
......@@ -234,6 +240,7 @@ static int __devinit via_pci_probe(struct pci_dev *pdev,
static void __devexit via_pci_remove(struct pci_dev *pdev)
{
viafb_destroy_gpios();
viafb_delete_i2c_busses();
via_fb_pci_remove(pdev);
via_pci_teardown_mmio(&global_dev);
......
/*
* 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 "via-core.h"
#include "via-gpio.h"
#include "global.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];
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 = viafb_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);
viafb_write_reg(gpio->vg_port_index, VIASR, 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];
viafb_write_reg_mask(gpio->vg_port_index, VIASR, 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 = viafb_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 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)
{
viafb_write_reg_mask(gpio->vg_port_index, VIASR, 0x02, 0x02);
}
static void viafb_gpio_disable(struct viafb_gpio *gpio)
{
viafb_write_reg_mask(gpio->vg_port_index, VIASR, 0, 0x02);
}
int viafb_create_gpios(struct viafb_dev *vdev,
const struct via_port_cfg *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) {
gpio_config.active_gpios[ngpio] = gpio;
gpio_config.gpio_names[ngpio] = gpio->vg_name;
ngpio++;
}
}
gpio_config.gpio_chip.ngpio = ngpio;
gpio_config.gpio_chip.names = gpio_config.gpio_names;
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(&gpio_config.vdev->reg_lock, flags);
for (i = 0; i < ngpio; i += 2)
viafb_gpio_enable(gpio_config.active_gpios[i]);
spin_unlock_irqrestore(&gpio_config.vdev->reg_lock, flags);
/*
* Get registered.
*/
gpio_config.gpio_chip.base = -1; /* Dynamic */
ret = gpiochip_add(&gpio_config.gpio_chip);
if (ret) {
printk(KERN_ERR "viafb: failed to add gpios (%d)\n", ret);
gpio_config.gpio_chip.ngpio = 0;
}
return ret;
/* Port enable ? */
}
int viafb_destroy_gpios(void)
{
unsigned long flags;
int ret = 0, i;
spin_lock_irqsave(&gpio_config.vdev->reg_lock, flags);
/*
* Get unregistered.
*/
if (gpio_config.gpio_chip.ngpio > 0) {
ret = gpiochip_remove(&gpio_config.gpio_chip);
if (ret) { /* Somebody still using it? */
printk(KERN_ERR "Viafb: GPIO remove failed\n");
goto out;
}
}
/*
* Disable the ports.
*/
for (i = 0; i < gpio_config.gpio_chip.ngpio; i += 2)
viafb_gpio_disable(gpio_config.active_gpios[i]);
gpio_config.gpio_chip.ngpio = 0;
out:
spin_unlock_irqrestore(&gpio_config.vdev->reg_lock, flags);
return ret;
}
/*
* 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 < gpio_config.gpio_chip.ngpio; i++)
if (!strcmp(name, gpio_config.active_gpios[i]->vg_name))
return gpio_config.gpio_chip.base + i;
return -1;
}
EXPORT_SYMBOL_GPL(viafb_gpio_lookup);
/*
* Support for viafb GPIO ports.
*
* Copyright 2009 Jonathan Corbet <corbet@lwn.net>
* Distributable under version 2 of the GNU General Public License.
*/
#ifndef __VIA_GPIO_H__
#define __VIA_GPIO_H__
extern int viafb_create_gpios(struct viafb_dev *vdev,
const struct via_port_cfg *port_cfg);
extern int viafb_destroy_gpios(void);
extern int viafb_gpio_lookup(const char *name);
#endif
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment