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_address.h> 25 #include <linux/module.h> 26 #include <linux/gpio/driver.h> 27 28 #define GEF_GPIO_DIRECT 0x00 29 #define GEF_GPIO_IN 0x04 30 #define GEF_GPIO_OUT 0x08 31 #define GEF_GPIO_TRIG 0x0C 32 #define GEF_GPIO_POLAR_A 0x10 33 #define GEF_GPIO_POLAR_B 0x14 34 #define GEF_GPIO_INT_STAT 0x18 35 #define GEF_GPIO_OVERRUN 0x1C 36 #define GEF_GPIO_MODE 0x20 37 38 static const struct of_device_id gef_gpio_ids[] = { 39 { 40 .compatible = "gef,sbc610-gpio", 41 .data = (void *)19, 42 }, { 43 .compatible = "gef,sbc310-gpio", 44 .data = (void *)6, 45 }, { 46 .compatible = "ge,imp3a-gpio", 47 .data = (void *)16, 48 }, 49 { } 50 }; 51 MODULE_DEVICE_TABLE(of, gef_gpio_ids); 52 53 static int __init gef_gpio_probe(struct platform_device *pdev) 54 { 55 struct gpio_chip *gc; 56 void __iomem *regs; 57 int ret; 58 59 gc = devm_kzalloc(&pdev->dev, sizeof(*gc), GFP_KERNEL); 60 if (!gc) 61 return -ENOMEM; 62 63 regs = of_iomap(pdev->dev.of_node, 0); 64 if (!regs) 65 return -ENOMEM; 66 67 ret = bgpio_init(gc, &pdev->dev, 4, regs + GEF_GPIO_IN, 68 regs + GEF_GPIO_OUT, NULL, NULL, 69 regs + GEF_GPIO_DIRECT, BGPIOF_BIG_ENDIAN_BYTE_ORDER); 70 if (ret) { 71 dev_err(&pdev->dev, "bgpio_init failed\n"); 72 goto err0; 73 } 74 75 /* Setup pointers to chip functions */ 76 gc->label = devm_kasprintf(&pdev->dev, GFP_KERNEL, "%pOF", pdev->dev.of_node); 77 if (!gc->label) { 78 ret = -ENOMEM; 79 goto err0; 80 } 81 82 gc->base = -1; 83 gc->ngpio = (u16)(uintptr_t)of_device_get_match_data(&pdev->dev); 84 gc->of_gpio_n_cells = 2; 85 86 /* This function adds a memory mapped GPIO chip */ 87 ret = devm_gpiochip_add_data(&pdev->dev, gc, NULL); 88 if (ret) 89 goto err0; 90 91 return 0; 92 err0: 93 iounmap(regs); 94 pr_err("%pOF: GPIO chip registration failed\n", pdev->dev.of_node); 95 return ret; 96 }; 97 98 static struct platform_driver gef_gpio_driver = { 99 .driver = { 100 .name = "gef-gpio", 101 .of_match_table = gef_gpio_ids, 102 }, 103 }; 104 module_platform_driver_probe(gef_gpio_driver, gef_gpio_probe); 105 106 MODULE_DESCRIPTION("GE I/O FPGA GPIO driver"); 107 MODULE_AUTHOR("Martyn Welch <martyn.welch@ge.com"); 108 MODULE_LICENSE("GPL"); 109