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/module.h> 10 #include <linux/of.h> 11 #include <linux/platform_device.h> 12 13 #define DEFAULT_PIN_NUMBER 16 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 device_node *node; 21 struct gpio_chip *chip; 22 void __iomem *base_addr; 23 int retval; 24 u32 ngpios; 25 26 chip = devm_kzalloc(&pdev->dev, sizeof(struct gpio_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 node = pdev->dev.of_node; 35 if (!node) 36 return -EINVAL; 37 38 retval = of_property_read_u32(node, "ngpios", &ngpios); 39 if (retval == -EINVAL) 40 ngpios = DEFAULT_PIN_NUMBER; 41 else if (retval) 42 return retval; 43 44 retval = bgpio_init(chip, &pdev->dev, 2, base_addr + INPUT_REG_OFFSET, 45 base_addr + OUTPUT_REG_OFFSET, NULL, 46 base_addr + DIRECTION_REG_OFFSET, NULL, 0); 47 if (retval) { 48 dev_err(&pdev->dev, "bgpio_init failed\n"); 49 return retval; 50 } 51 52 chip->ngpio = ngpios; 53 54 platform_set_drvdata(pdev, chip); 55 56 return devm_gpiochip_add_data(&pdev->dev, chip, NULL); 57 } 58 59 static const struct of_device_id ts4800_gpio_of_match[] = { 60 { .compatible = "technologic,ts4800-gpio", }, 61 {}, 62 }; 63 MODULE_DEVICE_TABLE(of, ts4800_gpio_of_match); 64 65 static struct platform_driver ts4800_gpio_driver = { 66 .driver = { 67 .name = "ts4800-gpio", 68 .of_match_table = ts4800_gpio_of_match, 69 }, 70 .probe = ts4800_gpio_probe, 71 }; 72 73 module_platform_driver_probe(ts4800_gpio_driver, ts4800_gpio_probe); 74 75 MODULE_AUTHOR("Julien Grossholtz <julien.grossholtz@savoirfairelinux.com>"); 76 MODULE_DESCRIPTION("TS4800 FPGA GPIO driver"); 77 MODULE_LICENSE("GPL v2"); 78