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_address.h> 11 #include <linux/of_device.h> 12 #include <linux/platform_device.h> 13 14 #define DEFAULT_PIN_NUMBER 16 15 #define INPUT_REG_OFFSET 0x00 16 #define OUTPUT_REG_OFFSET 0x02 17 #define DIRECTION_REG_OFFSET 0x04 18 19 static int ts4800_gpio_probe(struct platform_device *pdev) 20 { 21 struct device_node *node; 22 struct gpio_chip *chip; 23 void __iomem *base_addr; 24 int retval; 25 u32 ngpios; 26 27 chip = devm_kzalloc(&pdev->dev, sizeof(struct gpio_chip), GFP_KERNEL); 28 if (!chip) 29 return -ENOMEM; 30 31 base_addr = devm_platform_ioremap_resource(pdev, 0); 32 if (IS_ERR(base_addr)) 33 return PTR_ERR(base_addr); 34 35 node = pdev->dev.of_node; 36 if (!node) 37 return -EINVAL; 38 39 retval = of_property_read_u32(node, "ngpios", &ngpios); 40 if (retval == -EINVAL) 41 ngpios = DEFAULT_PIN_NUMBER; 42 else if (retval) 43 return retval; 44 45 retval = bgpio_init(chip, &pdev->dev, 2, base_addr + INPUT_REG_OFFSET, 46 base_addr + OUTPUT_REG_OFFSET, NULL, 47 base_addr + DIRECTION_REG_OFFSET, NULL, 0); 48 if (retval) { 49 dev_err(&pdev->dev, "bgpio_init failed\n"); 50 return retval; 51 } 52 53 chip->ngpio = ngpios; 54 55 platform_set_drvdata(pdev, chip); 56 57 return devm_gpiochip_add_data(&pdev->dev, chip, NULL); 58 } 59 60 static const struct of_device_id ts4800_gpio_of_match[] = { 61 { .compatible = "technologic,ts4800-gpio", }, 62 {}, 63 }; 64 MODULE_DEVICE_TABLE(of, ts4800_gpio_of_match); 65 66 static struct platform_driver ts4800_gpio_driver = { 67 .driver = { 68 .name = "ts4800-gpio", 69 .of_match_table = ts4800_gpio_of_match, 70 }, 71 .probe = ts4800_gpio_probe, 72 }; 73 74 module_platform_driver_probe(ts4800_gpio_driver, ts4800_gpio_probe); 75 76 MODULE_AUTHOR("Julien Grossholtz <julien.grossholtz@savoirfairelinux.com>"); 77 MODULE_DESCRIPTION("TS4800 FPGA GPIO driver"); 78 MODULE_LICENSE("GPL v2"); 79