1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Silicon Labs C2 port Linux support for Eurotech Duramar 2150 4 * 5 * Copyright (c) 2008 Rodolfo Giometti <giometti@linux.it> 6 * Copyright (c) 2008 Eurotech S.p.A. <info@eurotech.it> 7 */ 8 9 #include <linux/errno.h> 10 #include <linux/init.h> 11 #include <linux/kernel.h> 12 #include <linux/module.h> 13 #include <linux/delay.h> 14 #include <linux/io.h> 15 #include <linux/ioport.h> 16 #include <linux/c2port.h> 17 18 #define DATA_PORT 0x325 19 #define DIR_PORT 0x326 20 #define C2D (1 << 0) 21 #define C2CK (1 << 1) 22 23 static DEFINE_MUTEX(update_lock); 24 25 /* 26 * C2 port operations 27 */ 28 29 static void duramar2150_c2port_access(struct c2port_device *dev, int status) 30 { 31 u8 v; 32 33 mutex_lock(&update_lock); 34 35 v = inb(DIR_PORT); 36 37 /* 0 = input, 1 = output */ 38 if (status) 39 outb(v | (C2D | C2CK), DIR_PORT); 40 else 41 /* When access is "off" is important that both lines are set 42 * as inputs or hi-impedance */ 43 outb(v & ~(C2D | C2CK), DIR_PORT); 44 45 mutex_unlock(&update_lock); 46 } 47 48 static void duramar2150_c2port_c2d_dir(struct c2port_device *dev, int dir) 49 { 50 u8 v; 51 52 mutex_lock(&update_lock); 53 54 v = inb(DIR_PORT); 55 56 if (dir) 57 outb(v & ~C2D, DIR_PORT); 58 else 59 outb(v | C2D, DIR_PORT); 60 61 mutex_unlock(&update_lock); 62 } 63 64 static int duramar2150_c2port_c2d_get(struct c2port_device *dev) 65 { 66 return inb(DATA_PORT) & C2D; 67 } 68 69 static void duramar2150_c2port_c2d_set(struct c2port_device *dev, int status) 70 { 71 u8 v; 72 73 mutex_lock(&update_lock); 74 75 v = inb(DATA_PORT); 76 77 if (status) 78 outb(v | C2D, DATA_PORT); 79 else 80 outb(v & ~C2D, DATA_PORT); 81 82 mutex_unlock(&update_lock); 83 } 84 85 static void duramar2150_c2port_c2ck_set(struct c2port_device *dev, int status) 86 { 87 u8 v; 88 89 mutex_lock(&update_lock); 90 91 v = inb(DATA_PORT); 92 93 if (status) 94 outb(v | C2CK, DATA_PORT); 95 else 96 outb(v & ~C2CK, DATA_PORT); 97 98 mutex_unlock(&update_lock); 99 } 100 101 static struct c2port_ops duramar2150_c2port_ops = { 102 .block_size = 512, /* bytes */ 103 .blocks_num = 30, /* total flash size: 15360 bytes */ 104 105 .access = duramar2150_c2port_access, 106 .c2d_dir = duramar2150_c2port_c2d_dir, 107 .c2d_get = duramar2150_c2port_c2d_get, 108 .c2d_set = duramar2150_c2port_c2d_set, 109 .c2ck_set = duramar2150_c2port_c2ck_set, 110 }; 111 112 static struct c2port_device *duramar2150_c2port_dev; 113 114 /* 115 * Module stuff 116 */ 117 118 static int __init duramar2150_c2port_init(void) 119 { 120 struct resource *res; 121 int ret = 0; 122 123 res = request_region(0x325, 2, "c2port"); 124 if (!res) 125 return -EBUSY; 126 127 duramar2150_c2port_dev = c2port_device_register("uc", 128 &duramar2150_c2port_ops, NULL); 129 if (IS_ERR(duramar2150_c2port_dev)) { 130 ret = PTR_ERR(duramar2150_c2port_dev); 131 goto free_region; 132 } 133 134 return 0; 135 136 free_region: 137 release_region(0x325, 2); 138 return ret; 139 } 140 141 static void __exit duramar2150_c2port_exit(void) 142 { 143 /* Setup the GPIOs as input by default (access = 0) */ 144 duramar2150_c2port_access(duramar2150_c2port_dev, 0); 145 146 c2port_device_unregister(duramar2150_c2port_dev); 147 148 release_region(0x325, 2); 149 } 150 151 module_init(duramar2150_c2port_init); 152 module_exit(duramar2150_c2port_exit); 153 154 MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>"); 155 MODULE_DESCRIPTION("Silicon Labs C2 port Linux support for Duramar 2150"); 156 MODULE_LICENSE("GPL"); 157