Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 | // SPDX-License-Identifier: GPL-2.0-only /* linux/drivers/char/nsc_gpio.c National Semiconductor common GPIO device-file/VFS methods. Allows a user space process to control the GPIO pins. Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com> Copyright (c) 2005 Jim Cromie <jim.cromie@gmail.com> */ #include <linux/fs.h> #include <linux/module.h> #include <linux/errno.h> #include <linux/kernel.h> #include <linux/init.h> #include <linux/nsc_gpio.h> #include <linux/platform_device.h> #include <linux/uaccess.h> #include <asm/io.h> #define NAME "nsc_gpio" void nsc_gpio_dump(struct nsc_gpio_ops *amp, unsigned index) { /* retrieve current config w/o changing it */ u32 config = amp->gpio_config(index, ~0, 0); /* user requested via 'v' command, so its INFO */ dev_info(amp->dev, "io%02u: 0x%04x %s %s %s %s %s %s %s\tio:%d/%d\n", index, config, (config & 1) ? "OE" : "TS", /* output-enabled/tristate */ (config & 2) ? "PP" : "OD", /* push pull / open drain */ (config & 4) ? "PUE" : "PUD", /* pull up enabled/disabled */ (config & 8) ? "LOCKED" : "", /* locked / unlocked */ (config & 16) ? "LEVEL" : "EDGE",/* level/edge input */ (config & 32) ? "HI" : "LO", /* trigger on rise/fall edge */ (config & 64) ? "DEBOUNCE" : "", /* debounce */ amp->gpio_get(index), amp->gpio_current(index)); } ssize_t nsc_gpio_write(struct file *file, const char __user *data, size_t len, loff_t *ppos) { unsigned m = iminor(file_inode(file)); struct nsc_gpio_ops *amp = file->private_data; struct device *dev = amp->dev; size_t i; int err = 0; for (i = 0; i < len; ++i) { char c; if (get_user(c, data + i)) return -EFAULT; switch (c) { case '0': amp->gpio_set(m, 0); break; case '1': amp->gpio_set(m, 1); break; case 'O': dev_dbg(dev, "GPIO%d output enabled\n", m); amp->gpio_config(m, ~1, 1); break; case 'o': dev_dbg(dev, "GPIO%d output disabled\n", m); amp->gpio_config(m, ~1, 0); break; case 'T': dev_dbg(dev, "GPIO%d output is push pull\n", m); amp->gpio_config(m, ~2, 2); break; case 't': dev_dbg(dev, "GPIO%d output is open drain\n", m); amp->gpio_config(m, ~2, 0); break; case 'P': dev_dbg(dev, "GPIO%d pull up enabled\n", m); amp->gpio_config(m, ~4, 4); break; case 'p': dev_dbg(dev, "GPIO%d pull up disabled\n", m); amp->gpio_config(m, ~4, 0); break; case 'v': /* View Current pin settings */ amp->gpio_dump(amp, m); break; case '\n': /* end of settings string, do nothing */ break; default: dev_err(dev, "io%2d bad setting: chr<0x%2x>\n", m, (int)c); err++; } } if (err) return -EINVAL; /* full string handled, report error */ return len; } ssize_t nsc_gpio_read(struct file *file, char __user * buf, size_t len, loff_t * ppos) { unsigned m = iminor(file_inode(file)); int value; struct nsc_gpio_ops *amp = file->private_data; value = amp->gpio_get(m); if (put_user(value ? '1' : '0', buf)) return -EFAULT; return 1; } /* common file-ops routines for both scx200_gpio and pc87360_gpio */ EXPORT_SYMBOL(nsc_gpio_write); EXPORT_SYMBOL(nsc_gpio_read); EXPORT_SYMBOL(nsc_gpio_dump); static int __init nsc_gpio_init(void) { printk(KERN_DEBUG NAME " initializing\n"); return 0; } static void __exit nsc_gpio_cleanup(void) { printk(KERN_DEBUG NAME " cleanup\n"); } module_init(nsc_gpio_init); module_exit(nsc_gpio_cleanup); MODULE_AUTHOR("Jim Cromie <jim.cromie@gmail.com>"); MODULE_DESCRIPTION("NatSemi GPIO Common Methods"); MODULE_LICENSE("GPL"); |