131 lines
3.4 KiB
C
131 lines
3.4 KiB
C
/*
|
|
* Driver for GE FPGA based GPIO
|
|
*
|
|
* Author: Martyn Welch <martyn.welch@ge.com>
|
|
*
|
|
* 2008 (c) GE Intelligent Platforms Embedded Systems, Inc.
|
|
*
|
|
* This file is licensed under the terms of the GNU General Public License
|
|
* version 2. This program is licensed "as is" without any warranty of any
|
|
* kind, whether express or implied.
|
|
*/
|
|
|
|
/* TODO
|
|
*
|
|
* Configuration of output modes (totem-pole/open-drain)
|
|
* Interrupt configuration - interrupts are always generated the FPGA relies on
|
|
* the I/O interrupt controllers mask to stop them propergating
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/io.h>
|
|
#include <linux/of_device.h>
|
|
#include <linux/of_gpio.h>
|
|
#include <linux/module.h>
|
|
|
|
#define GEF_GPIO_DIRECT 0x00
|
|
#define GEF_GPIO_IN 0x04
|
|
#define GEF_GPIO_OUT 0x08
|
|
#define GEF_GPIO_TRIG 0x0C
|
|
#define GEF_GPIO_POLAR_A 0x10
|
|
#define GEF_GPIO_POLAR_B 0x14
|
|
#define GEF_GPIO_INT_STAT 0x18
|
|
#define GEF_GPIO_OVERRUN 0x1C
|
|
#define GEF_GPIO_MODE 0x20
|
|
|
|
static void gef_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
|
|
{
|
|
struct of_mm_gpio_chip *mmchip = to_of_mm_gpio_chip(chip);
|
|
unsigned int data;
|
|
|
|
data = ioread32be(mmchip->regs + GEF_GPIO_OUT);
|
|
if (value)
|
|
data = data | BIT(offset);
|
|
else
|
|
data = data & ~BIT(offset);
|
|
iowrite32be(data, mmchip->regs + GEF_GPIO_OUT);
|
|
}
|
|
|
|
static int gef_gpio_dir_in(struct gpio_chip *chip, unsigned offset)
|
|
{
|
|
unsigned int data;
|
|
struct of_mm_gpio_chip *mmchip = to_of_mm_gpio_chip(chip);
|
|
|
|
data = ioread32be(mmchip->regs + GEF_GPIO_DIRECT);
|
|
data = data | BIT(offset);
|
|
iowrite32be(data, mmchip->regs + GEF_GPIO_DIRECT);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int gef_gpio_dir_out(struct gpio_chip *chip, unsigned offset, int value)
|
|
{
|
|
unsigned int data;
|
|
struct of_mm_gpio_chip *mmchip = to_of_mm_gpio_chip(chip);
|
|
|
|
/* Set value before switching to output */
|
|
gef_gpio_set(mmchip->regs + GEF_GPIO_OUT, offset, value);
|
|
|
|
data = ioread32be(mmchip->regs + GEF_GPIO_DIRECT);
|
|
data = data & ~BIT(offset);
|
|
iowrite32be(data, mmchip->regs + GEF_GPIO_DIRECT);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int gef_gpio_get(struct gpio_chip *chip, unsigned offset)
|
|
{
|
|
struct of_mm_gpio_chip *mmchip = to_of_mm_gpio_chip(chip);
|
|
|
|
return !!(ioread32be(mmchip->regs + GEF_GPIO_IN) & BIT(offset));
|
|
}
|
|
|
|
static const struct of_device_id gef_gpio_ids[] = {
|
|
{
|
|
.compatible = "gef,sbc610-gpio",
|
|
.data = (void *)19,
|
|
}, {
|
|
.compatible = "gef,sbc310-gpio",
|
|
.data = (void *)6,
|
|
}, {
|
|
.compatible = "ge,imp3a-gpio",
|
|
.data = (void *)16,
|
|
},
|
|
{ }
|
|
};
|
|
MODULE_DEVICE_TABLE(of, gef_gpio_ids);
|
|
|
|
static int __init gef_gpio_probe(struct platform_device *pdev)
|
|
{
|
|
const struct of_device_id *of_id =
|
|
of_match_device(gef_gpio_ids, &pdev->dev);
|
|
struct of_mm_gpio_chip *mmchip;
|
|
|
|
mmchip = devm_kzalloc(&pdev->dev, sizeof(*mmchip), GFP_KERNEL);
|
|
if (!mmchip)
|
|
return -ENOMEM;
|
|
|
|
/* Setup pointers to chip functions */
|
|
mmchip->gc.ngpio = (u16)(uintptr_t)of_id->data;
|
|
mmchip->gc.of_gpio_n_cells = 2;
|
|
mmchip->gc.direction_input = gef_gpio_dir_in;
|
|
mmchip->gc.direction_output = gef_gpio_dir_out;
|
|
mmchip->gc.get = gef_gpio_get;
|
|
mmchip->gc.set = gef_gpio_set;
|
|
|
|
/* This function adds a memory mapped GPIO chip */
|
|
return of_mm_gpiochip_add(pdev->dev.of_node, mmchip);
|
|
};
|
|
|
|
static struct platform_driver gef_gpio_driver = {
|
|
.driver = {
|
|
.name = "gef-gpio",
|
|
.owner = THIS_MODULE,
|
|
.of_match_table = gef_gpio_ids,
|
|
},
|
|
};
|
|
module_platform_driver_probe(gef_gpio_driver, gef_gpio_probe);
|
|
|
|
MODULE_DESCRIPTION("GE I/O FPGA GPIO driver");
|
|
MODULE_AUTHOR("Martyn Welch <martyn.welch@ge.com");
|
|
MODULE_LICENSE("GPL");
|