1 /* 2 * GPIO driver for the TS-4800 board 3 * 4 * Copyright (c) 2016 - Savoir-faire Linux 5 * 6 * This file is licensed under the terms of the GNU General Public 7 * License version 2. This program is licensed "as is" without any 8 * warranty of any kind, whether express or implied. 9 */ 10 11 #include <linux/gpio/driver.h> 12 #include <linux/of_address.h> 13 #include <linux/of_device.h> 14 #include <linux/platform_device.h> 15 16 #define DEFAULT_PIN_NUMBER 16 17 #define INPUT_REG_OFFSET 0x00 18 #define OUTPUT_REG_OFFSET 0x02 19 #define DIRECTION_REG_OFFSET 0x04 20 21 static int ts4800_gpio_probe(struct platform_device *pdev) 22 { 23 struct device_node *node; 24 struct gpio_chip *chip; 25 struct resource *res; 26 void __iomem *base_addr; 27 int retval; 28 u32 ngpios; 29 30 chip = devm_kzalloc(&pdev->dev, sizeof(struct gpio_chip), GFP_KERNEL); 31 if (!chip) 32 return -ENOMEM; 33 34 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 35 base_addr = devm_ioremap_resource(&pdev->dev, res); 36 if (IS_ERR(base_addr)) 37 return PTR_ERR(base_addr); 38 39 node = pdev->dev.of_node; 40 if (!node) 41 return -EINVAL; 42 43 retval = of_property_read_u32(node, "ngpios", &ngpios); 44 if (retval == -EINVAL) 45 ngpios = DEFAULT_PIN_NUMBER; 46 else if (retval) 47 return retval; 48 49 retval = bgpio_init(chip, &pdev->dev, 2, base_addr + INPUT_REG_OFFSET, 50 base_addr + OUTPUT_REG_OFFSET, NULL, 51 base_addr + DIRECTION_REG_OFFSET, NULL, 0); 52 if (retval) { 53 dev_err(&pdev->dev, "bgpio_init failed\n"); 54 return retval; 55 } 56 57 chip->ngpio = ngpios; 58 59 platform_set_drvdata(pdev, chip); 60 61 return devm_gpiochip_add_data(&pdev->dev, chip, NULL); 62 } 63 64 static const struct of_device_id ts4800_gpio_of_match[] = { 65 { .compatible = "technologic,ts4800-gpio", }, 66 {}, 67 }; 68 69 static struct platform_driver ts4800_gpio_driver = { 70 .driver = { 71 .name = "ts4800-gpio", 72 .of_match_table = ts4800_gpio_of_match, 73 }, 74 .probe = ts4800_gpio_probe, 75 }; 76 77 module_platform_driver_probe(ts4800_gpio_driver, ts4800_gpio_probe); 78 79 MODULE_AUTHOR("Julien Grossholtz <julien.grossholtz@savoirfairelinux.com>"); 80 MODULE_DESCRIPTION("TS4800 FPGA GPIO driver"); 81 MODULE_LICENSE("GPL v2"); 82