| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * GPIO driver for the TS-4800 board |
| * |
| * Copyright (c) 2016 - Savoir-faire Linux |
| */ |
| |
| #include <linux/gpio/driver.h> |
| #include <linux/gpio/generic.h> |
| #include <linux/module.h> |
| #include <linux/platform_device.h> |
| #include <linux/property.h> |
| |
| #define DEFAULT_PIN_NUMBER 16 |
| #define INPUT_REG_OFFSET 0x00 |
| #define OUTPUT_REG_OFFSET 0x02 |
| #define DIRECTION_REG_OFFSET 0x04 |
| |
| static int ts4800_gpio_probe(struct platform_device *pdev) |
| { |
| struct gpio_generic_chip_config config; |
| struct device *dev = &pdev->dev; |
| struct gpio_generic_chip *chip; |
| void __iomem *base_addr; |
| int retval; |
| u32 ngpios; |
| |
| chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL); |
| if (!chip) |
| return -ENOMEM; |
| |
| base_addr = devm_platform_ioremap_resource(pdev, 0); |
| if (IS_ERR(base_addr)) |
| return PTR_ERR(base_addr); |
| |
| retval = device_property_read_u32(dev, "ngpios", &ngpios); |
| if (retval == -EINVAL) |
| ngpios = DEFAULT_PIN_NUMBER; |
| else if (retval) |
| return retval; |
| |
| config = (struct gpio_generic_chip_config) { |
| .dev = dev, |
| .sz = 2, |
| .dat = base_addr + INPUT_REG_OFFSET, |
| .set = base_addr + OUTPUT_REG_OFFSET, |
| .dirout = base_addr + DIRECTION_REG_OFFSET, |
| }; |
| |
| retval = gpio_generic_chip_init(chip, &config); |
| if (retval) |
| return dev_err_probe(dev, retval, |
| "failed to initialize the generic GPIO chip\n"); |
| |
| chip->gc.ngpio = ngpios; |
| |
| return devm_gpiochip_add_data(dev, &chip->gc, NULL); |
| } |
| |
| static const struct of_device_id ts4800_gpio_of_match[] = { |
| { .compatible = "technologic,ts4800-gpio", }, |
| {}, |
| }; |
| MODULE_DEVICE_TABLE(of, ts4800_gpio_of_match); |
| |
| static struct platform_driver ts4800_gpio_driver = { |
| .driver = { |
| .name = "ts4800-gpio", |
| .of_match_table = ts4800_gpio_of_match, |
| }, |
| .probe = ts4800_gpio_probe, |
| }; |
| |
| module_platform_driver_probe(ts4800_gpio_driver, ts4800_gpio_probe); |
| |
| MODULE_AUTHOR("Julien Grossholtz <julien.grossholtz@savoirfairelinux.com>"); |
| MODULE_DESCRIPTION("TS4800 FPGA GPIO driver"); |
| MODULE_LICENSE("GPL v2"); |