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/interrupt.h> 18 #include <linux/platform_device.h> 19 #include <linux/tty.h> 20 #include <linux/tty_flip.h> 21 #include <linux/slab.h> 22 #include <linux/io.h> 23 #include <linux/module.h> 24 25 enum { 26 GOLDFISH_TTY_PUT_CHAR = 0x00, 27 GOLDFISH_TTY_BYTES_READY = 0x04, 28 GOLDFISH_TTY_CMD = 0x08, 29 30 GOLDFISH_TTY_DATA_PTR = 0x10, 31 GOLDFISH_TTY_DATA_LEN = 0x14, 32 33 GOLDFISH_TTY_CMD_INT_DISABLE = 0, 34 GOLDFISH_TTY_CMD_INT_ENABLE = 1, 35 GOLDFISH_TTY_CMD_WRITE_BUFFER = 2, 36 GOLDFISH_TTY_CMD_READ_BUFFER = 3, 37 }; 38 39 struct goldfish_tty { 40 struct tty_port port; 41 spinlock_t lock; 42 void __iomem *base; 43 u32 irq; 44 int opencount; 45 struct console console; 46 }; 47 48 static DEFINE_MUTEX(goldfish_tty_lock); 49 static struct tty_driver *goldfish_tty_driver; 50 static u32 goldfish_tty_line_count = 8; 51 static u32 goldfish_tty_current_line_count; 52 static struct goldfish_tty *goldfish_ttys; 53 54 static void goldfish_tty_do_write(int line, const char *buf, unsigned count) 55 { 56 unsigned long irq_flags; 57 struct goldfish_tty *qtty = &goldfish_ttys[line]; 58 void __iomem *base = qtty->base; 59 spin_lock_irqsave(&qtty->lock, irq_flags); 60 writel((u32)buf, base + GOLDFISH_TTY_DATA_PTR); 61 writel(count, base + GOLDFISH_TTY_DATA_LEN); 62 writel(GOLDFISH_TTY_CMD_WRITE_BUFFER, base + GOLDFISH_TTY_CMD); 63 spin_unlock_irqrestore(&qtty->lock, irq_flags); 64 } 65 66 static irqreturn_t goldfish_tty_interrupt(int irq, void *dev_id) 67 { 68 struct platform_device *pdev = dev_id; 69 struct goldfish_tty *qtty = &goldfish_ttys[pdev->id]; 70 void __iomem *base = qtty->base; 71 unsigned long irq_flags; 72 unsigned char *buf; 73 u32 count; 74 75 count = readl(base + GOLDFISH_TTY_BYTES_READY); 76 if(count == 0) 77 return IRQ_NONE; 78 79 count = tty_prepare_flip_string(&qtty->port, &buf, count); 80 spin_lock_irqsave(&qtty->lock, irq_flags); 81 writel((u32)buf, base + GOLDFISH_TTY_DATA_PTR); 82 writel(count, base + GOLDFISH_TTY_DATA_LEN); 83 writel(GOLDFISH_TTY_CMD_READ_BUFFER, base + GOLDFISH_TTY_CMD); 84 spin_unlock_irqrestore(&qtty->lock, irq_flags); 85 tty_schedule_flip(&qtty->port); 86 return IRQ_HANDLED; 87 } 88 89 static int goldfish_tty_activate(struct tty_port *port, struct tty_struct *tty) 90 { 91 struct goldfish_tty *qtty = container_of(port, struct goldfish_tty, port); 92 writel(GOLDFISH_TTY_CMD_INT_ENABLE, qtty->base + GOLDFISH_TTY_CMD); 93 return 0; 94 } 95 96 static void goldfish_tty_shutdown(struct tty_port *port) 97 { 98 struct goldfish_tty *qtty = container_of(port, struct goldfish_tty, port); 99 writel(GOLDFISH_TTY_CMD_INT_DISABLE, qtty->base + GOLDFISH_TTY_CMD); 100 } 101 102 static int goldfish_tty_open(struct tty_struct * tty, struct file * filp) 103 { 104 struct goldfish_tty *qtty = &goldfish_ttys[tty->index]; 105 return tty_port_open(&qtty->port, tty, filp); 106 } 107 108 static void goldfish_tty_close(struct tty_struct * tty, struct file * filp) 109 { 110 tty_port_close(tty->port, tty, filp); 111 } 112 113 static void goldfish_tty_hangup(struct tty_struct *tty) 114 { 115 tty_port_hangup(tty->port); 116 } 117 118 static int goldfish_tty_write(struct tty_struct * tty, const unsigned char *buf, int count) 119 { 120 goldfish_tty_do_write(tty->index, buf, count); 121 return count; 122 } 123 124 static int goldfish_tty_write_room(struct tty_struct *tty) 125 { 126 return 0x10000; 127 } 128 129 static int goldfish_tty_chars_in_buffer(struct tty_struct *tty) 130 { 131 struct goldfish_tty *qtty = &goldfish_ttys[tty->index]; 132 void __iomem *base = qtty->base; 133 return readl(base + GOLDFISH_TTY_BYTES_READY); 134 } 135 136 static void goldfish_tty_console_write(struct console *co, const char *b, unsigned count) 137 { 138 goldfish_tty_do_write(co->index, b, count); 139 } 140 141 static struct tty_driver *goldfish_tty_console_device(struct console *c, int *index) 142 { 143 *index = c->index; 144 return goldfish_tty_driver; 145 } 146 147 static int goldfish_tty_console_setup(struct console *co, char *options) 148 { 149 if((unsigned)co->index > goldfish_tty_line_count) 150 return -ENODEV; 151 if(goldfish_ttys[co->index].base == 0) 152 return -ENODEV; 153 return 0; 154 } 155 156 static struct tty_port_operations goldfish_port_ops = { 157 .activate = goldfish_tty_activate, 158 .shutdown = goldfish_tty_shutdown 159 }; 160 161 static struct tty_operations goldfish_tty_ops = { 162 .open = goldfish_tty_open, 163 .close = goldfish_tty_close, 164 .hangup = goldfish_tty_hangup, 165 .write = goldfish_tty_write, 166 .write_room = goldfish_tty_write_room, 167 .chars_in_buffer = goldfish_tty_chars_in_buffer, 168 }; 169 170 static int goldfish_tty_create_driver(void) 171 { 172 int ret; 173 struct tty_driver *tty; 174 175 goldfish_ttys = kzalloc(sizeof(*goldfish_ttys) * goldfish_tty_line_count, GFP_KERNEL); 176 if(goldfish_ttys == NULL) { 177 ret = -ENOMEM; 178 goto err_alloc_goldfish_ttys_failed; 179 } 180 tty = alloc_tty_driver(goldfish_tty_line_count); 181 if(tty == NULL) { 182 ret = -ENOMEM; 183 goto err_alloc_tty_driver_failed; 184 } 185 tty->driver_name = "goldfish"; 186 tty->name = "ttyGF"; 187 tty->type = TTY_DRIVER_TYPE_SERIAL; 188 tty->subtype = SERIAL_TYPE_NORMAL; 189 tty->init_termios = tty_std_termios; 190 tty->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV; 191 tty_set_operations(tty, &goldfish_tty_ops); 192 ret = tty_register_driver(tty); 193 if(ret) 194 goto err_tty_register_driver_failed; 195 196 goldfish_tty_driver = tty; 197 return 0; 198 199 err_tty_register_driver_failed: 200 put_tty_driver(tty); 201 err_alloc_tty_driver_failed: 202 kfree(goldfish_ttys); 203 goldfish_ttys = NULL; 204 err_alloc_goldfish_ttys_failed: 205 return ret; 206 } 207 208 static void goldfish_tty_delete_driver(void) 209 { 210 tty_unregister_driver(goldfish_tty_driver); 211 put_tty_driver(goldfish_tty_driver); 212 goldfish_tty_driver = NULL; 213 kfree(goldfish_ttys); 214 goldfish_ttys = NULL; 215 } 216 217 static int goldfish_tty_probe(struct platform_device *pdev) 218 { 219 struct goldfish_tty *qtty; 220 int ret = -EINVAL; 221 int i; 222 struct resource *r; 223 struct device *ttydev; 224 void __iomem *base; 225 u32 irq; 226 227 r = platform_get_resource(pdev, IORESOURCE_MEM, 0); 228 if(r == NULL) 229 return -EINVAL; 230 231 base = ioremap(r->start, 0x1000); 232 if (base == NULL) 233 pr_err("goldfish_tty: unable to remap base\n"); 234 235 r = platform_get_resource(pdev, IORESOURCE_IRQ, 0); 236 if(r == NULL) 237 goto err_unmap; 238 239 irq = r->start; 240 241 if(pdev->id >= goldfish_tty_line_count) 242 goto err_unmap; 243 244 mutex_lock(&goldfish_tty_lock); 245 if(goldfish_tty_current_line_count == 0) { 246 ret = goldfish_tty_create_driver(); 247 if(ret) 248 goto err_create_driver_failed; 249 } 250 goldfish_tty_current_line_count++; 251 252 qtty = &goldfish_ttys[pdev->id]; 253 spin_lock_init(&qtty->lock); 254 tty_port_init(&qtty->port); 255 qtty->port.ops = &goldfish_port_ops; 256 qtty->base = base; 257 qtty->irq = irq; 258 259 writel(GOLDFISH_TTY_CMD_INT_DISABLE, base + GOLDFISH_TTY_CMD); 260 261 ret = request_irq(irq, goldfish_tty_interrupt, IRQF_SHARED, "goldfish_tty", pdev); 262 if(ret) 263 goto err_request_irq_failed; 264 265 266 ttydev = tty_port_register_device(&qtty->port, goldfish_tty_driver, 267 pdev->id, &pdev->dev); 268 if(IS_ERR(ttydev)) { 269 ret = PTR_ERR(ttydev); 270 goto err_tty_register_device_failed; 271 } 272 273 strcpy(qtty->console.name, "ttyGF"); 274 qtty->console.write = goldfish_tty_console_write; 275 qtty->console.device = goldfish_tty_console_device; 276 qtty->console.setup = goldfish_tty_console_setup; 277 qtty->console.flags = CON_PRINTBUFFER; 278 qtty->console.index = pdev->id; 279 register_console(&qtty->console); 280 281 mutex_unlock(&goldfish_tty_lock); 282 return 0; 283 284 tty_unregister_device(goldfish_tty_driver, i); 285 err_tty_register_device_failed: 286 free_irq(irq, pdev); 287 err_request_irq_failed: 288 goldfish_tty_current_line_count--; 289 if(goldfish_tty_current_line_count == 0) 290 goldfish_tty_delete_driver(); 291 err_create_driver_failed: 292 mutex_unlock(&goldfish_tty_lock); 293 err_unmap: 294 iounmap(base); 295 return ret; 296 } 297 298 static int goldfish_tty_remove(struct platform_device *pdev) 299 { 300 struct goldfish_tty *qtty; 301 302 mutex_lock(&goldfish_tty_lock); 303 304 qtty = &goldfish_ttys[pdev->id]; 305 unregister_console(&qtty->console); 306 tty_unregister_device(goldfish_tty_driver, pdev->id); 307 iounmap(qtty->base); 308 qtty->base = 0; 309 free_irq(qtty->irq, pdev); 310 goldfish_tty_current_line_count--; 311 if(goldfish_tty_current_line_count == 0) 312 goldfish_tty_delete_driver(); 313 mutex_unlock(&goldfish_tty_lock); 314 return 0; 315 } 316 317 static struct platform_driver goldfish_tty_platform_driver = { 318 .probe = goldfish_tty_probe, 319 .remove = goldfish_tty_remove, 320 .driver = { 321 .name = "goldfish_tty" 322 } 323 }; 324 325 module_platform_driver(goldfish_tty_platform_driver); 326 327 MODULE_LICENSE("GPL v2"); 328