diff options
Diffstat (limited to 'drivers/gpio/gpio-ge.c')
| -rw-r--r-- | drivers/gpio/gpio-ge.c | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-ge.c b/drivers/gpio/gpio-ge.c new file mode 100644 index 00000000000..1237a73c3c9 --- /dev/null +++ b/drivers/gpio/gpio-ge.c @@ -0,0 +1,131 @@ +/* + * 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"); |