diff options
Diffstat (limited to 'arch/powerpc/platforms/86xx/gef_gpio.c')
| -rw-r--r-- | arch/powerpc/platforms/86xx/gef_gpio.c | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/86xx/gef_gpio.c b/arch/powerpc/platforms/86xx/gef_gpio.c new file mode 100644 index 000000000000..85b2800f4cb7 --- /dev/null +++ b/arch/powerpc/platforms/86xx/gef_gpio.c @@ -0,0 +1,143 @@ +/* + * Driver for GE Fanuc's FPGA based GPIO pins + * + * Author: Martyn Welch <martyn.welch@gefanuc.com> + * + * 2008 (c) GE Fanuc 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/compiler.h> +#include <linux/init.h> +#include <linux/io.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/of_platform.h> +#include <linux/of_gpio.h> +#include <linux/gpio.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 + +#define NUM_GPIO 19 + +static void _gef_gpio_set(void __iomem *reg, unsigned int offset, int value) +{ + unsigned int data; + + data = ioread32be(reg); + /* value: 0=low; 1=high */ + if (value & 0x1) + data = data | (0x1 << offset); + else + data = data & ~(0x1 << offset); + + iowrite32be(data, reg); +} + + +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 | (0x1 << 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 direction before switching to input */ + _gef_gpio_set(mmchip->regs + GEF_GPIO_OUT, offset, value); + + data = ioread32be(mmchip->regs + GEF_GPIO_DIRECT); + data = data & ~(0x1 << offset); + iowrite32be(data, mmchip->regs + GEF_GPIO_DIRECT); + + return 0; +} + +static int gef_gpio_get(struct gpio_chip *chip, unsigned offset) +{ + unsigned int data; + int state = 0; + struct of_mm_gpio_chip *mmchip = to_of_mm_gpio_chip(chip); + + data = ioread32be(mmchip->regs + GEF_GPIO_IN); + state = (int)((data >> offset) & 0x1); + + return state; +} + +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); + + _gef_gpio_set(mmchip->regs + GEF_GPIO_OUT, offset, value); +} + +static int __init gef_gpio_init(void) +{ + struct device_node *np; + + for_each_compatible_node(np, NULL, "gef,sbc610-gpio") { + int retval; + struct of_mm_gpio_chip *gef_gpio_chip; + + pr_debug("%s: Initialising GEF GPIO\n", np->full_name); + + /* Allocate chip structure */ + gef_gpio_chip = kzalloc(sizeof(*gef_gpio_chip), GFP_KERNEL); + if (!gef_gpio_chip) { + pr_err("%s: Unable to allocate structure\n", + np->full_name); + continue; + } + + /* Setup pointers to chip functions */ + gef_gpio_chip->of_gc.gpio_cells = 2; + gef_gpio_chip->of_gc.gc.ngpio = NUM_GPIO; + gef_gpio_chip->of_gc.gc.direction_input = gef_gpio_dir_in; + gef_gpio_chip->of_gc.gc.direction_output = gef_gpio_dir_out; + gef_gpio_chip->of_gc.gc.get = gef_gpio_get; + gef_gpio_chip->of_gc.gc.set = gef_gpio_set; + + /* This function adds a memory mapped GPIO chip */ + retval = of_mm_gpiochip_add(np, gef_gpio_chip); + if (retval) { + kfree(gef_gpio_chip); + pr_err("%s: Unable to add GPIO\n", np->full_name); + } + } + + return 0; +}; +arch_initcall(gef_gpio_init); + +MODULE_DESCRIPTION("GE Fanuc I/O FPGA GPIO driver"); +MODULE_AUTHOR("Martyn Welch <martyn.welch@gefanuc.com"); +MODULE_LICENSE("GPL"); |