1 /* 2 * Copyright (C) 2007 Google, Inc. 3 * Copyright (C) 2012 Intel, Inc. 4 * 5 * This software is licensed under the terms of the GNU General Public 6 * License version 2, as published by the Free Software Foundation, and 7 * may be copied, distributed, and modified under those terms. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 */ 15 16 #include <linux/console.h> 17 #include <linux/init.h> 18 #include <linux/interrupt.h> 19 #include <linux/platform_device.h> 20 #include <linux/tty.h> 21 #include <linux/tty_flip.h> 22 #include <linux/slab.h> 23 #include <linux/io.h> 24 #include <linux/module.h> 25 26 enum { 27 GOLDFISH_TTY_PUT_CHAR = 0x00, 28 GOLDFISH_TTY_BYTES_READY = 0x04, 29 GOLDFISH_TTY_CMD = 0x08, 30 31 GOLDFISH_TTY_DATA_PTR = 0x10, 32 GOLDFISH_TTY_DATA_LEN = 0x14, 33 34 GOLDFISH_TTY_CMD_INT_DISABLE = 0, 35 GOLDFISH_TTY_CMD_INT_ENABLE = 1, 36 GOLDFISH_TTY_CMD_WRITE_BUFFER = 2, 37 GOLDFISH_TTY_CMD_READ_BUFFER = 3, 38 }; 39 40 struct goldfish_tty { 41 struct tty_port port; 42 spinlock_t lock; 43 void __iomem *base; 44 u32 irq; 45 int opencount; 46 struct console console; 47 }; 48 49 static DEFINE_MUTEX(goldfish_tty_lock); 50 static struct tty_driver *goldfish_tty_driver; 51 static u32 goldfish_tty_line_count = 8; 52 static u32 goldfish_tty_current_line_count; 53 static struct goldfish_tty *goldfish_ttys; 54 55 static void goldfish_tty_do_write(int line, const char *buf, unsigned count) 56 { 57 unsigned long irq_flags; 58 struct goldfish_tty *qtty = &goldfish_ttys[line]; 59 void __iomem *base = qtty->base; 60 spin_lock_irqsave(&qtty->lock, irq_flags); 61 writel((u32)buf, base + GOLDFISH_TTY_DATA_PTR); 62 writel(count, base + GOLDFISH_TTY_DATA_LEN); 63 writel(GOLDFISH_TTY_CMD_WRITE_BUFFER, base + GOLDFISH_TTY_CMD); 64 spin_unlock_irqrestore(&qtty->lock, irq_flags); 65 } 66 67 static irqreturn_t goldfish_tty_interrupt(int irq, void *dev_id) 68 { 69 struct platform_device *pdev = dev_id; 70 struct goldfish_tty *qtty = &goldfish_ttys[pdev->id]; 71 void __iomem *base = qtty->base; 72 unsigned long irq_flags; 73 unsigned char *buf; 74 u32 count; 75 76 count = readl(base + GOLDFISH_TTY_BYTES_READY); 77 if(count == 0) 78 return IRQ_NONE; 79 80 count = tty_prepare_flip_string(&qtty->port, &buf, count); 81 spin_lock_irqsave(&qtty->lock, irq_flags); 82 writel((u32)buf, base + GOLDFISH_TTY_DATA_PTR); 83 writel(count, base + GOLDFISH_TTY_DATA_LEN); 84 writel(GOLDFISH_TTY_CMD_READ_BUFFER, base + GOLDFISH_TTY_CMD); 85 spin_unlock_irqrestore(&qtty->lock, irq_flags); 86 tty_schedule_flip(&qtty->port); 87 return IRQ_HANDLED; 88 } 89 90 static int goldfish_tty_activate(struct tty_port *port, struct tty_struct *tty) 91 { 92 struct goldfish_tty *qtty = container_of(port, struct goldfish_tty, port); 93 writel(GOLDFISH_TTY_CMD_INT_ENABLE, qtty->base + GOLDFISH_TTY_CMD); 94 return 0; 95 } 96 97 static void goldfish_tty_shutdown(struct tty_port *port) 98 { 99 struct goldfish_tty *qtty = container_of(port, struct goldfish_tty, port); 100 writel(GOLDFISH_TTY_CMD_INT_DISABLE, qtty->base + GOLDFISH_TTY_CMD); 101 } 102 103 static int goldfish_tty_open(struct tty_struct * tty, struct file * filp) 104 { 105 struct goldfish_tty *qtty = &goldfish_ttys[tty->index]; 106 return tty_port_open(&qtty->port, tty, filp); 107 } 108 109 static void goldfish_tty_close(struct tty_struct * tty, struct file * filp) 110 { 111 tty_port_close(tty->port, tty, filp); 112 } 113 114 static void goldfish_tty_hangup(struct tty_struct *tty) 115 { 116 tty_port_hangup(tty->port); 117 } 118 119 static int goldfish_tty_write(struct tty_struct * tty, const unsigned char *buf, int count) 120 { 121 goldfish_tty_do_write(tty->index, buf, count); 122 return count; 123 } 124 125 static int goldfish_tty_write_room(struct tty_struct *tty) 126 { 127 return 0x10000; 128 } 129 130 static int goldfish_tty_chars_in_buffer(struct tty_struct *tty) 131 { 132 struct goldfish_tty *qtty = &goldfish_ttys[tty->index]; 133 void __iomem *base = qtty->base; 134 return readl(base + GOLDFISH_TTY_BYTES_READY); 135 } 136 137 static void goldfish_tty_console_write(struct console *co, const char *b, unsigned count) 138 { 139 goldfish_tty_do_write(co->index, b, count); 140 } 141 142 static struct tty_driver *goldfish_tty_console_device(struct console *c, int *index) 143 { 144 *index = c->index; 145 return goldfish_tty_driver; 146 } 147 148 static int goldfish_tty_console_setup(struct console *co, char *options) 149 { 150 if((unsigned)co->index > goldfish_tty_line_count) 151 return -ENODEV; 152 if(goldfish_ttys[co->index].base == 0) 153 return -ENODEV; 154 return 0; 155 } 156 157 static struct tty_port_operations goldfish_port_ops = { 158 .activate = goldfish_tty_activate, 159 .shutdown = goldfish_tty_shutdown 160 }; 161 162 static struct tty_operations goldfish_tty_ops = { 163 .open = goldfish_tty_open, 164 .close = goldfish_tty_close, 165 .hangup = goldfish_tty_hangup, 166 .write = goldfish_tty_write, 167 .write_room = goldfish_tty_write_room, 168 .chars_in_buffer = goldfish_tty_chars_in_buffer, 169 }; 170 171 static int goldfish_tty_create_driver(void) 172 { 173 int ret; 174 struct tty_driver *tty; 175 176 goldfish_ttys = kzalloc(sizeof(*goldfish_ttys) * goldfish_tty_line_count, GFP_KERNEL); 177 if(goldfish_ttys == NULL) { 178 ret = -ENOMEM; 179 goto err_alloc_goldfish_ttys_failed; 180 } 181 tty = alloc_tty_driver(goldfish_tty_line_count); 182 if(tty == NULL) { 183 ret = -ENOMEM; 184 goto err_alloc_tty_driver_failed; 185 } 186 tty->driver_name = "goldfish"; 187 tty->name = "ttyGF"; 188 tty->type = TTY_DRIVER_TYPE_SERIAL; 189 tty->subtype = SERIAL_TYPE_NORMAL; 190 tty->init_termios = tty_std_termios; 191 tty->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV; 192 tty_set_operations(tty, &goldfish_tty_ops); 193 ret = tty_register_driver(tty); 194 if(ret) 195 goto err_tty_register_driver_failed; 196 197 goldfish_tty_driver = tty; 198 return 0; 199 200 err_tty_register_driver_failed: 201 put_tty_driver(tty); 202 err_alloc_tty_driver_failed: 203 kfree(goldfish_ttys); 204 goldfish_ttys = NULL; 205 err_alloc_goldfish_ttys_failed: 206 return ret; 207 } 208 209 static void goldfish_tty_delete_driver(void) 210 { 211 tty_unregister_driver(goldfish_tty_driver); 212 put_tty_driver(goldfish_tty_driver); 213 goldfish_tty_driver = NULL; 214 kfree(goldfish_ttys); 215 goldfish_ttys = NULL; 216 } 217 218 static int goldfish_tty_probe(struct platform_device *pdev) 219 { 220 struct goldfish_tty *qtty; 221 int ret = -EINVAL; 222 int i; 223 struct resource *r; 224 struct device *ttydev; 225 void __iomem *base; 226 u32 irq; 227 228 r = platform_get_resource(pdev, IORESOURCE_MEM, 0); 229 if(r == NULL) 230 return -EINVAL; 231 232 base = ioremap(r->start, 0x1000); 233 if (base == NULL) 234 pr_err("goldfish_tty: unable to remap base\n"); 235 236 r = platform_get_resource(pdev, IORESOURCE_IRQ, 0); 237 if(r == NULL) 238 goto err_unmap; 239 240 irq = r->start; 241 242 if(pdev->id >= goldfish_tty_line_count) 243 goto err_unmap; 244 245 mutex_lock(&goldfish_tty_lock); 246 if(goldfish_tty_current_line_count == 0) { 247 ret = goldfish_tty_create_driver(); 248 if(ret) 249 goto err_create_driver_failed; 250 } 251 goldfish_tty_current_line_count++; 252 253 qtty = &goldfish_ttys[pdev->id]; 254 spin_lock_init(&qtty->lock); 255 tty_port_init(&qtty->port); 256 qtty->port.ops = &goldfish_port_ops; 257 qtty->base = base; 258 qtty->irq = irq; 259 260 writel(GOLDFISH_TTY_CMD_INT_DISABLE, base + GOLDFISH_TTY_CMD); 261 262 ret = request_irq(irq, goldfish_tty_interrupt, IRQF_SHARED, "goldfish_tty", pdev); 263 if(ret) 264 goto err_request_irq_failed; 265 266 267 ttydev = tty_port_register_device(&qtty->port, goldfish_tty_driver, 268 pdev->id, &pdev->dev); 269 if(IS_ERR(ttydev)) { 270 ret = PTR_ERR(ttydev); 271 goto err_tty_register_device_failed; 272 } 273 274 strcpy(qtty->console.name, "ttyGF"); 275 qtty->console.write = goldfish_tty_console_write; 276 qtty->console.device = goldfish_tty_console_device; 277 qtty->console.setup = goldfish_tty_console_setup; 278 qtty->console.flags = CON_PRINTBUFFER; 279 qtty->console.index = pdev->id; 280 register_console(&qtty->console); 281 282 mutex_unlock(&goldfish_tty_lock); 283 return 0; 284 285 tty_unregister_device(goldfish_tty_driver, i); 286 err_tty_register_device_failed: 287 free_irq(irq, pdev); 288 err_request_irq_failed: 289 goldfish_tty_current_line_count--; 290 if(goldfish_tty_current_line_count == 0) 291 goldfish_tty_delete_driver(); 292 err_create_driver_failed: 293 mutex_unlock(&goldfish_tty_lock); 294 err_unmap: 295 iounmap(base); 296 return ret; 297 } 298 299 static int goldfish_tty_remove(struct platform_device *pdev) 300 { 301 struct goldfish_tty *qtty; 302 303 mutex_lock(&goldfish_tty_lock); 304 305 qtty = &goldfish_ttys[pdev->id]; 306 unregister_console(&qtty->console); 307 tty_unregister_device(goldfish_tty_driver, pdev->id); 308 iounmap(qtty->base); 309 qtty->base = 0; 310 free_irq(qtty->irq, pdev); 311 goldfish_tty_current_line_count--; 312 if(goldfish_tty_current_line_count == 0) 313 goldfish_tty_delete_driver(); 314 mutex_unlock(&goldfish_tty_lock); 315 return 0; 316 } 317 318 static struct platform_driver goldfish_tty_platform_driver = { 319 .probe = goldfish_tty_probe, 320 .remove = goldfish_tty_remove, 321 .driver = { 322 .name = "goldfish_tty" 323 } 324 }; 325 326 module_platform_driver(goldfish_tty_platform_driver); 327 328 MODULE_LICENSE("GPL v2"); 329