1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * /dev/lcd driver for Apple Network Servers. 4 */ 5 6 #include <linux/types.h> 7 #include <linux/errno.h> 8 #include <linux/kernel.h> 9 #include <linux/miscdevice.h> 10 #include <linux/fcntl.h> 11 #include <linux/module.h> 12 #include <linux/delay.h> 13 #include <linux/fs.h> 14 #include <linux/of.h> 15 16 #include <linux/uaccess.h> 17 #include <asm/sections.h> 18 #include <asm/io.h> 19 20 #include "ans-lcd.h" 21 22 #define ANSLCD_ADDR 0xf301c000 23 #define ANSLCD_CTRL_IX 0x00 24 #define ANSLCD_DATA_IX 0x10 25 26 static unsigned long anslcd_short_delay = 80; 27 static unsigned long anslcd_long_delay = 3280; 28 static volatile unsigned char __iomem *anslcd_ptr; 29 static DEFINE_MUTEX(anslcd_mutex); 30 31 #undef DEBUG 32 33 static void 34 anslcd_write_byte_ctrl ( unsigned char c ) 35 { 36 #ifdef DEBUG 37 printk(KERN_DEBUG "LCD: CTRL byte: %02x\n",c); 38 #endif 39 out_8(anslcd_ptr + ANSLCD_CTRL_IX, c); 40 switch(c) { 41 case 1: 42 case 2: 43 case 3: 44 udelay(anslcd_long_delay); break; 45 default: udelay(anslcd_short_delay); 46 } 47 } 48 49 static void 50 anslcd_write_byte_data ( unsigned char c ) 51 { 52 out_8(anslcd_ptr + ANSLCD_DATA_IX, c); 53 udelay(anslcd_short_delay); 54 } 55 56 static ssize_t 57 anslcd_write( struct file * file, const char __user * buf, 58 size_t count, loff_t *ppos ) 59 { 60 const char __user *p = buf; 61 int i; 62 63 #ifdef DEBUG 64 printk(KERN_DEBUG "LCD: write\n"); 65 #endif 66 67 if (!access_ok(buf, count)) 68 return -EFAULT; 69 70 mutex_lock(&anslcd_mutex); 71 for ( i = *ppos; count > 0; ++i, ++p, --count ) 72 { 73 char c; 74 __get_user(c, p); 75 anslcd_write_byte_data( c ); 76 } 77 mutex_unlock(&anslcd_mutex); 78 *ppos = i; 79 return p - buf; 80 } 81 82 static long 83 anslcd_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 84 { 85 char ch, __user *temp; 86 long ret = 0; 87 88 #ifdef DEBUG 89 printk(KERN_DEBUG "LCD: ioctl(%d,%d)\n",cmd,arg); 90 #endif 91 92 mutex_lock(&anslcd_mutex); 93 94 switch ( cmd ) 95 { 96 case ANSLCD_CLEAR: 97 anslcd_write_byte_ctrl ( 0x38 ); 98 anslcd_write_byte_ctrl ( 0x0f ); 99 anslcd_write_byte_ctrl ( 0x06 ); 100 anslcd_write_byte_ctrl ( 0x01 ); 101 anslcd_write_byte_ctrl ( 0x02 ); 102 break; 103 case ANSLCD_SENDCTRL: 104 temp = (char __user *) arg; 105 __get_user(ch, temp); 106 for (; ch; temp++) { /* FIXME: This is ugly, but should work, as a \0 byte is not a valid command code */ 107 anslcd_write_byte_ctrl ( ch ); 108 __get_user(ch, temp); 109 } 110 break; 111 case ANSLCD_SETSHORTDELAY: 112 if (!capable(CAP_SYS_ADMIN)) 113 ret =-EACCES; 114 else 115 anslcd_short_delay=arg; 116 break; 117 case ANSLCD_SETLONGDELAY: 118 if (!capable(CAP_SYS_ADMIN)) 119 ret = -EACCES; 120 else 121 anslcd_long_delay=arg; 122 break; 123 default: 124 ret = -EINVAL; 125 } 126 127 mutex_unlock(&anslcd_mutex); 128 return ret; 129 } 130 131 static int 132 anslcd_open( struct inode * inode, struct file * file ) 133 { 134 return 0; 135 } 136 137 const struct file_operations anslcd_fops = { 138 .write = anslcd_write, 139 .unlocked_ioctl = anslcd_ioctl, 140 .open = anslcd_open, 141 .llseek = default_llseek, 142 }; 143 144 static struct miscdevice anslcd_dev = { 145 LCD_MINOR, 146 "anslcd", 147 &anslcd_fops 148 }; 149 150 static const char anslcd_logo[] __initconst = 151 "********************" /* Line #1 */ 152 "* LINUX! *" /* Line #3 */ 153 "* Welcome to *" /* Line #2 */ 154 "********************"; /* Line #4 */ 155 156 static int __init 157 anslcd_init(void) 158 { 159 int a; 160 int retval; 161 struct device_node* node; 162 163 node = of_find_node_by_name(NULL, "lcd"); 164 if (!node || !of_node_name_eq(node->parent, "gc")) { 165 of_node_put(node); 166 return -ENODEV; 167 } 168 of_node_put(node); 169 170 anslcd_ptr = ioremap(ANSLCD_ADDR, 0x20); 171 172 retval = misc_register(&anslcd_dev); 173 if(retval < 0){ 174 printk(KERN_INFO "LCD: misc_register failed\n"); 175 iounmap(anslcd_ptr); 176 return retval; 177 } 178 179 #ifdef DEBUG 180 printk(KERN_DEBUG "LCD: init\n"); 181 #endif 182 183 mutex_lock(&anslcd_mutex); 184 anslcd_write_byte_ctrl ( 0x38 ); 185 anslcd_write_byte_ctrl ( 0x0c ); 186 anslcd_write_byte_ctrl ( 0x06 ); 187 anslcd_write_byte_ctrl ( 0x01 ); 188 anslcd_write_byte_ctrl ( 0x02 ); 189 for(a=0;a<80;a++) { 190 anslcd_write_byte_data(anslcd_logo[a]); 191 } 192 mutex_unlock(&anslcd_mutex); 193 return 0; 194 } 195 196 static void __exit 197 anslcd_exit(void) 198 { 199 misc_deregister(&anslcd_dev); 200 iounmap(anslcd_ptr); 201 } 202 203 module_init(anslcd_init); 204 module_exit(anslcd_exit); 205 MODULE_LICENSE("GPL v2"); 206