1 /* 2 * Driver for GE FPGA based GPIO 3 * 4 * Author: Martyn Welch <martyn.welch@ge.com> 5 * 6 * 2008 (c) GE Intelligent Platforms Embedded Systems, Inc. 7 * 8 * This file is licensed under the terms of the GNU General Public License 9 * version 2. This program is licensed "as is" without any warranty of any 10 * kind, whether express or implied. 11 */ 12 13 /* TODO 14 * 15 * Configuration of output modes (totem-pole/open-drain) 16 * Interrupt configuration - interrupts are always generated the FPGA relies on 17 * the I/O interrupt controllers mask to stop them propergating 18 */ 19 20 #include <linux/kernel.h> 21 #include <linux/io.h> 22 #include <linux/slab.h> 23 #include <linux/of_device.h> 24 #include <linux/of_gpio.h> 25 #include <linux/of_address.h> 26 #include <linux/module.h> 27 #include <linux/gpio/driver.h> 28 29 #define GEF_GPIO_DIRECT 0x00 30 #define GEF_GPIO_IN 0x04 31 #define GEF_GPIO_OUT 0x08 32 #define GEF_GPIO_TRIG 0x0C 33 #define GEF_GPIO_POLAR_A 0x10 34 #define GEF_GPIO_POLAR_B 0x14 35 #define GEF_GPIO_INT_STAT 0x18 36 #define GEF_GPIO_OVERRUN 0x1C 37 #define GEF_GPIO_MODE 0x20 38 39 static const struct of_device_id gef_gpio_ids[] = { 40 { 41 .compatible = "gef,sbc610-gpio", 42 .data = (void *)19, 43 }, { 44 .compatible = "gef,sbc310-gpio", 45 .data = (void *)6, 46 }, { 47 .compatible = "ge,imp3a-gpio", 48 .data = (void *)16, 49 }, 50 { } 51 }; 52 MODULE_DEVICE_TABLE(of, gef_gpio_ids); 53 54 static int __init gef_gpio_probe(struct platform_device *pdev) 55 { 56 const struct of_device_id *of_id = 57 of_match_device(gef_gpio_ids, &pdev->dev); 58 struct gpio_chip *gc; 59 void __iomem *regs; 60 int ret; 61 62 gc = devm_kzalloc(&pdev->dev, sizeof(*gc), GFP_KERNEL); 63 if (!gc) 64 return -ENOMEM; 65 66 regs = of_iomap(pdev->dev.of_node, 0); 67 if (!regs) 68 return -ENOMEM; 69 70 ret = bgpio_init(gc, &pdev->dev, 4, regs + GEF_GPIO_IN, 71 regs + GEF_GPIO_OUT, NULL, NULL, 72 regs + GEF_GPIO_DIRECT, BGPIOF_BIG_ENDIAN_BYTE_ORDER); 73 if (ret) { 74 dev_err(&pdev->dev, "bgpio_init failed\n"); 75 goto err0; 76 } 77 78 /* Setup pointers to chip functions */ 79 gc->label = devm_kasprintf(&pdev->dev, GFP_KERNEL, "%pOF", pdev->dev.of_node); 80 if (!gc->label) { 81 ret = -ENOMEM; 82 goto err0; 83 } 84 85 gc->base = -1; 86 gc->ngpio = (u16)(uintptr_t)of_id->data; 87 gc->of_gpio_n_cells = 2; 88 gc->of_node = pdev->dev.of_node; 89 90 /* This function adds a memory mapped GPIO chip */ 91 ret = devm_gpiochip_add_data(&pdev->dev, gc, NULL); 92 if (ret) 93 goto err0; 94 95 return 0; 96 err0: 97 iounmap(regs); 98 pr_err("%pOF: GPIO chip registration failed\n", pdev->dev.of_node); 99 return ret; 100 }; 101 102 static struct platform_driver gef_gpio_driver = { 103 .driver = { 104 .name = "gef-gpio", 105 .of_match_table = gef_gpio_ids, 106 }, 107 }; 108 module_platform_driver_probe(gef_gpio_driver, gef_gpio_probe); 109 110 MODULE_DESCRIPTION("GE I/O FPGA GPIO driver"); 111 MODULE_AUTHOR("Martyn Welch <martyn.welch@ge.com"); 112 MODULE_LICENSE("GPL"); 113