Jim Cromie | 62c83cd | 2006-06-27 02:54:13 -0700 | [diff] [blame] | 1 | /* linux/drivers/char/scx200_gpio.c |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2 | |
| 3 | National Semiconductor SCx200 GPIO driver. Allows a user space |
| 4 | process to play with the GPIO pins. |
| 5 | |
| 6 | Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com> */ |
| 7 | |
Jim Cromie | 979b5ec | 2006-06-27 02:54:14 -0700 | [diff] [blame] | 8 | #include <linux/device.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 9 | #include <linux/fs.h> |
| 10 | #include <linux/module.h> |
| 11 | #include <linux/errno.h> |
| 12 | #include <linux/kernel.h> |
| 13 | #include <linux/init.h> |
Jim Cromie | 979b5ec | 2006-06-27 02:54:14 -0700 | [diff] [blame] | 14 | #include <linux/platform_device.h> |
Jonathan Corbet | f2b9857 | 2008-05-18 15:32:43 -0600 | [diff] [blame] | 15 | #include <linux/smp_lock.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 16 | #include <asm/uaccess.h> |
| 17 | #include <asm/io.h> |
| 18 | |
Jim Cromie | 7d7f212 | 2006-06-27 02:54:14 -0700 | [diff] [blame] | 19 | #include <linux/types.h> |
| 20 | #include <linux/cdev.h> |
| 21 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 22 | #include <linux/scx200_gpio.h> |
Jim Cromie | fe3a168 | 2006-06-27 02:54:18 -0700 | [diff] [blame] | 23 | #include <linux/nsc_gpio.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 24 | |
Jim Cromie | ae2d1f2f | 2006-07-14 00:24:16 -0700 | [diff] [blame] | 25 | #define DRVNAME "scx200_gpio" |
Jim Cromie | 979b5ec | 2006-06-27 02:54:14 -0700 | [diff] [blame] | 26 | |
| 27 | static struct platform_device *pdev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 28 | |
| 29 | MODULE_AUTHOR("Christer Weinigel <wingel@nano-system.com>"); |
Jim Cromie | ae2d1f2f | 2006-07-14 00:24:16 -0700 | [diff] [blame] | 30 | MODULE_DESCRIPTION("NatSemi/AMD SCx200 GPIO Pin Driver"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 31 | MODULE_LICENSE("GPL"); |
| 32 | |
| 33 | static int major = 0; /* default to dynamic major */ |
| 34 | module_param(major, int, 0); |
| 35 | MODULE_PARM_DESC(major, "Major device number"); |
| 36 | |
Jim Cromie | ae2d1f2f | 2006-07-14 00:24:16 -0700 | [diff] [blame] | 37 | #define MAX_PINS 32 /* 64 later, when known ok */ |
| 38 | |
Jim Cromie | 2e8f7a3 | 2006-07-14 00:24:26 -0700 | [diff] [blame] | 39 | struct nsc_gpio_ops scx200_gpio_ops = { |
Jim Cromie | fe3a168 | 2006-06-27 02:54:18 -0700 | [diff] [blame] | 40 | .owner = THIS_MODULE, |
| 41 | .gpio_config = scx200_gpio_configure, |
Jim Cromie | 0e41ef3 | 2006-06-27 02:54:20 -0700 | [diff] [blame] | 42 | .gpio_dump = nsc_gpio_dump, |
Jim Cromie | fe3a168 | 2006-06-27 02:54:18 -0700 | [diff] [blame] | 43 | .gpio_get = scx200_gpio_get, |
| 44 | .gpio_set = scx200_gpio_set, |
Jim Cromie | fe3a168 | 2006-06-27 02:54:18 -0700 | [diff] [blame] | 45 | .gpio_change = scx200_gpio_change, |
| 46 | .gpio_current = scx200_gpio_current |
| 47 | }; |
Chris Boot | 58012cd | 2006-09-29 01:59:07 -0700 | [diff] [blame] | 48 | EXPORT_SYMBOL_GPL(scx200_gpio_ops); |
Jim Cromie | fe3a168 | 2006-06-27 02:54:18 -0700 | [diff] [blame] | 49 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 50 | static int scx200_gpio_open(struct inode *inode, struct file *file) |
| 51 | { |
| 52 | unsigned m = iminor(inode); |
Jim Cromie | 2e8f7a3 | 2006-07-14 00:24:26 -0700 | [diff] [blame] | 53 | file->private_data = &scx200_gpio_ops; |
Jim Cromie | c3dc807 | 2006-06-27 02:54:18 -0700 | [diff] [blame] | 54 | |
Jonathan Corbet | f2b9857 | 2008-05-18 15:32:43 -0600 | [diff] [blame] | 55 | cycle_kernel_lock(); |
Jim Cromie | ae2d1f2f | 2006-07-14 00:24:16 -0700 | [diff] [blame] | 56 | if (m >= MAX_PINS) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 57 | return -EINVAL; |
| 58 | return nonseekable_open(inode, file); |
| 59 | } |
| 60 | |
| 61 | static int scx200_gpio_release(struct inode *inode, struct file *file) |
| 62 | { |
| 63 | return 0; |
| 64 | } |
| 65 | |
Jim Cromie | 2e8f7a3 | 2006-07-14 00:24:26 -0700 | [diff] [blame] | 66 | static const struct file_operations scx200_gpio_fileops = { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 67 | .owner = THIS_MODULE, |
Jim Cromie | 1a66fdf | 2006-06-27 02:54:20 -0700 | [diff] [blame] | 68 | .write = nsc_gpio_write, |
| 69 | .read = nsc_gpio_read, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 70 | .open = scx200_gpio_open, |
| 71 | .release = scx200_gpio_release, |
| 72 | }; |
| 73 | |
Jim Cromie | c8ad968 | 2006-09-29 01:59:05 -0700 | [diff] [blame] | 74 | static struct cdev scx200_gpio_cdev; /* use 1 cdev for all pins */ |
Jim Cromie | 7d7f212 | 2006-06-27 02:54:14 -0700 | [diff] [blame] | 75 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 76 | static int __init scx200_gpio_init(void) |
| 77 | { |
Jim Cromie | 635adb6 | 2006-07-14 00:24:16 -0700 | [diff] [blame] | 78 | int rc; |
Jim Cromie | ae2d1f2f | 2006-07-14 00:24:16 -0700 | [diff] [blame] | 79 | dev_t devid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 80 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 81 | if (!scx200_gpio_present()) { |
Jim Cromie | ae2d1f2f | 2006-07-14 00:24:16 -0700 | [diff] [blame] | 82 | printk(KERN_ERR DRVNAME ": no SCx200 gpio present\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 83 | return -ENODEV; |
| 84 | } |
Jim Cromie | 979b5ec | 2006-06-27 02:54:14 -0700 | [diff] [blame] | 85 | |
| 86 | /* support dev_dbg() with pdev->dev */ |
Jim Cromie | ae2d1f2f | 2006-07-14 00:24:16 -0700 | [diff] [blame] | 87 | pdev = platform_device_alloc(DRVNAME, 0); |
Jim Cromie | 979b5ec | 2006-06-27 02:54:14 -0700 | [diff] [blame] | 88 | if (!pdev) |
| 89 | return -ENOMEM; |
| 90 | |
| 91 | rc = platform_device_add(pdev); |
| 92 | if (rc) |
| 93 | goto undo_malloc; |
| 94 | |
Jim Cromie | f31000e | 2006-06-27 02:54:23 -0700 | [diff] [blame] | 95 | /* nsc_gpio uses dev_dbg(), so needs this */ |
Jim Cromie | 2e8f7a3 | 2006-07-14 00:24:26 -0700 | [diff] [blame] | 96 | scx200_gpio_ops.dev = &pdev->dev; |
Jim Cromie | f31000e | 2006-06-27 02:54:23 -0700 | [diff] [blame] | 97 | |
Jim Cromie | ae2d1f2f | 2006-07-14 00:24:16 -0700 | [diff] [blame] | 98 | if (major) { |
| 99 | devid = MKDEV(major, 0); |
| 100 | rc = register_chrdev_region(devid, MAX_PINS, "scx200_gpio"); |
| 101 | } else { |
| 102 | rc = alloc_chrdev_region(&devid, 0, MAX_PINS, "scx200_gpio"); |
| 103 | major = MAJOR(devid); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 104 | } |
Jim Cromie | 7d7f212 | 2006-06-27 02:54:14 -0700 | [diff] [blame] | 105 | if (rc < 0) { |
Jim Cromie | 979b5ec | 2006-06-27 02:54:14 -0700 | [diff] [blame] | 106 | dev_err(&pdev->dev, "SCx200 chrdev_region err: %d\n", rc); |
| 107 | goto undo_platform_device_add; |
Jim Cromie | 7d7f212 | 2006-06-27 02:54:14 -0700 | [diff] [blame] | 108 | } |
Jim Cromie | 635adb6 | 2006-07-14 00:24:16 -0700 | [diff] [blame] | 109 | |
Jim Cromie | 2e8f7a3 | 2006-07-14 00:24:26 -0700 | [diff] [blame] | 110 | cdev_init(&scx200_gpio_cdev, &scx200_gpio_fileops); |
Jim Cromie | 635adb6 | 2006-07-14 00:24:16 -0700 | [diff] [blame] | 111 | cdev_add(&scx200_gpio_cdev, devid, MAX_PINS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 112 | |
Jim Cromie | 979b5ec | 2006-06-27 02:54:14 -0700 | [diff] [blame] | 113 | return 0; /* succeed */ |
Jim Cromie | 7d7f212 | 2006-06-27 02:54:14 -0700 | [diff] [blame] | 114 | |
Jim Cromie | 979b5ec | 2006-06-27 02:54:14 -0700 | [diff] [blame] | 115 | undo_platform_device_add: |
Ingo Molnar | 1017f6a | 2006-06-30 01:55:29 -0700 | [diff] [blame] | 116 | platform_device_del(pdev); |
Jim Cromie | 979b5ec | 2006-06-27 02:54:14 -0700 | [diff] [blame] | 117 | undo_malloc: |
Ingo Molnar | 1017f6a | 2006-06-30 01:55:29 -0700 | [diff] [blame] | 118 | platform_device_put(pdev); |
| 119 | |
Jim Cromie | 7d7f212 | 2006-06-27 02:54:14 -0700 | [diff] [blame] | 120 | return rc; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 121 | } |
| 122 | |
| 123 | static void __exit scx200_gpio_cleanup(void) |
| 124 | { |
Jim Cromie | 635adb6 | 2006-07-14 00:24:16 -0700 | [diff] [blame] | 125 | cdev_del(&scx200_gpio_cdev); |
| 126 | /* cdev_put(&scx200_gpio_cdev); */ |
| 127 | |
Jim Cromie | ae2d1f2f | 2006-07-14 00:24:16 -0700 | [diff] [blame] | 128 | unregister_chrdev_region(MKDEV(major, 0), MAX_PINS); |
Jim Cromie | 979b5ec | 2006-06-27 02:54:14 -0700 | [diff] [blame] | 129 | platform_device_unregister(pdev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 130 | } |
| 131 | |
| 132 | module_init(scx200_gpio_init); |
| 133 | module_exit(scx200_gpio_cleanup); |