1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Driver for GE FPGA based GPIO 4 * 5 * Author: Martyn Welch <martyn.welch@ge.com> 6 * 7 * 2008 (c) GE Intelligent Platforms Embedded Systems, Inc. 8 */ 9 10 /* 11 * TODO: 12 * 13 * Configuration of output modes (totem-pole/open-drain). 14 * Interrupt configuration - interrupts are always generated, the FPGA relies 15 * on the I/O interrupt controllers mask to stop them from being propagated. 16 */ 17 18 #include <linux/gpio/driver.h> 19 #include <linux/gpio/generic.h> 20 #include <linux/io.h> 21 #include <linux/kernel.h> 22 #include <linux/module.h> 23 #include <linux/platform_device.h> 24 #include <linux/property.h> 25 #include <linux/slab.h> 26 27 #define GEF_GPIO_DIRECT 0x00 28 #define GEF_GPIO_IN 0x04 29 #define GEF_GPIO_OUT 0x08 30 #define GEF_GPIO_TRIG 0x0C 31 #define GEF_GPIO_POLAR_A 0x10 32 #define GEF_GPIO_POLAR_B 0x14 33 #define GEF_GPIO_INT_STAT 0x18 34 #define GEF_GPIO_OVERRUN 0x1C 35 #define GEF_GPIO_MODE 0x20 36 37 static const struct of_device_id gef_gpio_ids[] = { 38 { 39 .compatible = "gef,sbc610-gpio", 40 .data = (void *)19, 41 }, { 42 .compatible = "gef,sbc310-gpio", 43 .data = (void *)6, 44 }, { 45 .compatible = "ge,imp3a-gpio", 46 .data = (void *)16, 47 }, 48 { } 49 }; 50 MODULE_DEVICE_TABLE(of, gef_gpio_ids); 51 52 static int __init gef_gpio_probe(struct platform_device *pdev) 53 { 54 struct gpio_generic_chip_config config; 55 struct device *dev = &pdev->dev; 56 struct gpio_generic_chip *chip; 57 struct gpio_chip *gc; 58 void __iomem *regs; 59 int ret; 60 61 chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL); 62 if (!chip) 63 return -ENOMEM; 64 65 regs = devm_platform_ioremap_resource(pdev, 0); 66 if (IS_ERR(regs)) 67 return PTR_ERR(regs); 68 69 config = (struct gpio_generic_chip_config) { 70 .dev = dev, 71 .sz = 4, 72 .dat = regs + GEF_GPIO_IN, 73 .set = regs + GEF_GPIO_OUT, 74 .dirin = regs + GEF_GPIO_DIRECT, 75 .flags = GPIO_GENERIC_BIG_ENDIAN_BYTE_ORDER, 76 }; 77 78 ret = gpio_generic_chip_init(chip, &config); 79 if (ret) 80 return dev_err_probe(dev, ret, 81 "failed to initialize the generic GPIO chip\n"); 82 83 gc = &chip->gc; 84 85 /* Setup pointers to chip functions */ 86 gc->label = devm_kasprintf(dev, GFP_KERNEL, "%pfw", dev_fwnode(dev)); 87 if (!gc->label) 88 return -ENOMEM; 89 90 gc->base = -1; 91 gc->ngpio = (uintptr_t)device_get_match_data(dev); 92 93 /* This function adds a memory mapped GPIO chip */ 94 ret = devm_gpiochip_add_data(dev, gc, NULL); 95 if (ret) 96 return dev_err_probe(dev, ret, "GPIO chip registration failed\n"); 97 98 return 0; 99 }; 100 101 static struct platform_driver gef_gpio_driver = { 102 .driver = { 103 .name = "gef-gpio", 104 .of_match_table = gef_gpio_ids, 105 }, 106 }; 107 module_platform_driver_probe(gef_gpio_driver, gef_gpio_probe); 108 109 MODULE_DESCRIPTION("GE I/O FPGA GPIO driver"); 110 MODULE_AUTHOR("Martyn Welch <martyn.welch@ge.com>"); 111 MODULE_LICENSE("GPL"); 112