1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * GPIO driver for the TS-4800 board 4 * 5 * Copyright (c) 2016 - Savoir-faire Linux 6 */ 7 8 #include <linux/gpio/driver.h> 9 #include <linux/gpio/generic.h> 10 #include <linux/module.h> 11 #include <linux/platform_device.h> 12 #include <linux/property.h> 13 14 #define INPUT_REG_OFFSET 0x00 15 #define OUTPUT_REG_OFFSET 0x02 16 #define DIRECTION_REG_OFFSET 0x04 17 18 static int ts4800_gpio_probe(struct platform_device *pdev) 19 { 20 struct gpio_generic_chip_config config; 21 struct device *dev = &pdev->dev; 22 struct gpio_generic_chip *chip; 23 void __iomem *base_addr; 24 int retval; 25 26 chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL); 27 if (!chip) 28 return -ENOMEM; 29 30 base_addr = devm_platform_ioremap_resource(pdev, 0); 31 if (IS_ERR(base_addr)) 32 return PTR_ERR(base_addr); 33 34 config = (struct gpio_generic_chip_config) { 35 .dev = dev, 36 .sz = 2, 37 .dat = base_addr + INPUT_REG_OFFSET, 38 .set = base_addr + OUTPUT_REG_OFFSET, 39 .dirout = base_addr + DIRECTION_REG_OFFSET, 40 }; 41 42 retval = gpio_generic_chip_init(chip, &config); 43 if (retval) 44 return dev_err_probe(dev, retval, 45 "failed to initialize the generic GPIO chip\n"); 46 47 return devm_gpiochip_add_data(dev, &chip->gc, NULL); 48 } 49 50 static const struct of_device_id ts4800_gpio_of_match[] = { 51 { .compatible = "technologic,ts4800-gpio", }, 52 {}, 53 }; 54 MODULE_DEVICE_TABLE(of, ts4800_gpio_of_match); 55 56 static struct platform_driver ts4800_gpio_driver = { 57 .driver = { 58 .name = "ts4800-gpio", 59 .of_match_table = ts4800_gpio_of_match, 60 }, 61 .probe = ts4800_gpio_probe, 62 }; 63 64 module_platform_driver_probe(ts4800_gpio_driver, ts4800_gpio_probe); 65 66 MODULE_AUTHOR("Julien Grossholtz <julien.grossholtz@savoirfairelinux.com>"); 67 MODULE_DESCRIPTION("TS4800 FPGA GPIO driver"); 68 MODULE_LICENSE("GPL v2"); 69