drivers/input/serio/sa1111ps2.c

   1 /*
   2  *  linux/drivers/input/serio/sa1111ps2.c
   3  *
   4  *  Copyright (C) 2002 Russell King
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License.
   9  */
  10 #include <linux/module.h>
  11 #include <linux/init.h>
  12 #include <linux/input.h>
  13 #include <linux/serio.h>
  14 #include <linux/errno.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/ioport.h>
  17 #include <linux/delay.h>
  18 #include <linux/device.h>
  19 #include <linux/slab.h>
  20 #include <linux/spinlock.h>
  21
  22 #include <asm/io.h>
  23
  24 #include <asm/hardware/sa1111.h>
  25
  26 #define PS2CR           0x0000
  27 #define PS2STAT         0x0004
  28 #define PS2DATA         0x0008
  29 #define PS2CLKDIV       0x000c
  30 #define PS2PRECNT       0x0010
  31
  32 #define PS2CR_ENA       0x08
  33 #define PS2CR_FKD       0x02
  34 #define PS2CR_FKC       0x01
  35
  36 #define PS2STAT_STP     0x0100
  37 #define PS2STAT_TXE     0x0080
  38 #define PS2STAT_TXB     0x0040
  39 #define PS2STAT_RXF     0x0020
  40 #define PS2STAT_RXB     0x0010
  41 #define PS2STAT_ENA     0x0008
  42 #define PS2STAT_RXP     0x0004
  43 #define PS2STAT_KBD     0x0002
  44 #define PS2STAT_KBC     0x0001
  45
  46 struct ps2if {
  47         struct serio            *io;
  48         struct sa1111_dev       *dev;
  49         void __iomem            *base;
  50         unsigned int            open;
  51         spinlock_t              lock;
  52         unsigned int            head;
  53         unsigned int            tail;
  54         unsigned char           buf[4];
  55 };
  56
  57 /*
  58  * Read all bytes waiting in the PS2 port.  There should be
  59  * at the most one, but we loop for safety.  If there was a
  60  * framing error, we have to manually clear the status.
  61  */
  62 static irqreturn_t ps2_rxint(int irq, void *dev_id)
  63 {
  64         struct ps2if *ps2if = dev_id;
  65         unsigned int scancode, flag, status;
  66
  67         status = sa1111_readl(ps2if->base + PS2STAT);
  68         while (status & PS2STAT_RXF) {
  69                 if (status & PS2STAT_STP)
  70                         sa1111_writel(PS2STAT_STP, ps2if->base + PS2STAT);
  71
  72                 flag = (status & PS2STAT_STP ? SERIO_FRAME : 0) |
  73                        (status & PS2STAT_RXP ? 0 : SERIO_PARITY);
  74
  75                 scancode = sa1111_readl(ps2if->base + PS2DATA) & 0xff;
  76
  77                 if (hweight8(scancode) & 1)
  78                         flag ^= SERIO_PARITY;
  79
  80                 serio_interrupt(ps2if->io, scancode, flag);
  81
  82                 status = sa1111_readl(ps2if->base + PS2STAT);
  83         }
  84
  85         return IRQ_HANDLED;
  86 }
  87
  88 /*
  89  * Completion of ps2 write
  90  */
  91 static irqreturn_t ps2_txint(int irq, void *dev_id)
  92 {
  93         struct ps2if *ps2if = dev_id;
  94         unsigned int status;
  95
  96         spin_lock(&ps2if->lock);
  97         status = sa1111_readl(ps2if->base + PS2STAT);
  98         if (ps2if->head == ps2if->tail) {
  99                 disable_irq_nosync(irq);
 100                 /* done */
 101         } else if (status & PS2STAT_TXE) {
 102                 sa1111_writel(ps2if->buf[ps2if->tail], ps2if->base + PS2DATA);
 103                 ps2if->tail = (ps2if->tail + 1) & (sizeof(ps2if->buf) - 1);
 104         }
 105         spin_unlock(&ps2if->lock);
 106
 107         return IRQ_HANDLED;
 108 }
 109
 110 /*
 111  * Write a byte to the PS2 port.  We have to wait for the
 112  * port to indicate that the transmitter is empty.
 113  */
 114 static int ps2_write(struct serio *io, unsigned char val)
 115 {
 116         struct ps2if *ps2if = io->port_data;
 117         unsigned long flags;
 118         unsigned int head;
 119
 120         spin_lock_irqsave(&ps2if->lock, flags);
 121
 122         /*
 123          * If the TX register is empty, we can go straight out.
 124          */
 125         if (sa1111_readl(ps2if->base + PS2STAT) & PS2STAT_TXE) {
 126                 sa1111_writel(val, ps2if->base + PS2DATA);
 127         } else {
 128                 if (ps2if->head == ps2if->tail)
 129                         enable_irq(ps2if->dev->irq[1]);
 130                 head = (ps2if->head + 1) & (sizeof(ps2if->buf) - 1);
 131                 if (head != ps2if->tail) {
 132                         ps2if->buf[ps2if->head] = val;
 133                         ps2if->head = head;
 134                 }
 135         }
 136
 137         spin_unlock_irqrestore(&ps2if->lock, flags);
 138         return 0;
 139 }
 140
 141 static int ps2_open(struct serio *io)
 142 {
 143         struct ps2if *ps2if = io->port_data;
 144         int ret;
 145
 146         ret = sa1111_enable_device(ps2if->dev);
 147         if (ret)
 148                 return ret;
 149
 150         ret = request_irq(ps2if->dev->irq[0], ps2_rxint, 0,
 151                           SA1111_DRIVER_NAME(ps2if->dev), ps2if);
 152         if (ret) {
 153                 printk(KERN_ERR "sa1111ps2: could not allocate IRQ%d: %d\n",
 154                         ps2if->dev->irq[0], ret);
 155                 sa1111_disable_device(ps2if->dev);
 156                 return ret;
 157         }
 158
 159         ret = request_irq(ps2if->dev->irq[1], ps2_txint, 0,
 160                           SA1111_DRIVER_NAME(ps2if->dev), ps2if);
 161         if (ret) {
 162                 printk(KERN_ERR "sa1111ps2: could not allocate IRQ%d: %d\n",
 163                         ps2if->dev->irq[1], ret);
 164                 free_irq(ps2if->dev->irq[0], ps2if);
 165                 sa1111_disable_device(ps2if->dev);
 166                 return ret;
 167         }
 168
 169         ps2if->open = 1;
 170
 171         enable_irq_wake(ps2if->dev->irq[0]);
 172
 173         sa1111_writel(PS2CR_ENA, ps2if->base + PS2CR);
 174         return 0;
 175 }
 176
 177 static void ps2_close(struct serio *io)
 178 {
 179         struct ps2if *ps2if = io->port_data;
 180
 181         sa1111_writel(0, ps2if->base + PS2CR);
 182
 183         disable_irq_wake(ps2if->dev->irq[0]);
 184
 185         ps2if->open = 0;
 186
 187         free_irq(ps2if->dev->irq[1], ps2if);
 188         free_irq(ps2if->dev->irq[0], ps2if);
 189
 190         sa1111_disable_device(ps2if->dev);
 191 }
 192
 193 /*
 194  * Clear the input buffer.
 195  */
 196 static void ps2_clear_input(struct ps2if *ps2if)
 197 {
 198         int maxread = 100;
 199
 200         while (maxread--) {
 201                 if ((sa1111_readl(ps2if->base + PS2DATA) & 0xff) == 0xff)
 202                         break;
 203         }
 204 }
 205
 206 static unsigned int ps2_test_one(struct ps2if *ps2if,
 207                                            unsigned int mask)
 208 {
 209         unsigned int val;
 210
 211         sa1111_writel(PS2CR_ENA | mask, ps2if->base + PS2CR);
 212
 213         udelay(2);
 214
 215         val = sa1111_readl(ps2if->base + PS2STAT);
 216         return val & (PS2STAT_KBC | PS2STAT_KBD);
 217 }
 218
 219 /*
 220  * Test the keyboard interface.  We basically check to make sure that
 221  * we can drive each line to the keyboard independently of each other.
 222  */
 223 static int ps2_test(struct ps2if *ps2if)
 224 {
 225         unsigned int stat;
 226         int ret = 0;
 227
 228         stat = ps2_test_one(ps2if, PS2CR_FKC);
 229         if (stat != PS2STAT_KBD) {
 230                 printk("PS/2 interface test failed[1]: %02x\n", stat);
 231                 ret = -ENODEV;
 232         }
 233
 234         stat = ps2_test_one(ps2if, 0);
 235         if (stat != (PS2STAT_KBC | PS2STAT_KBD)) {
 236                 printk("PS/2 interface test failed[2]: %02x\n", stat);
 237                 ret = -ENODEV;
 238         }
 239
 240         stat = ps2_test_one(ps2if, PS2CR_FKD);
 241         if (stat != PS2STAT_KBC) {
 242                 printk("PS/2 interface test failed[3]: %02x\n", stat);
 243                 ret = -ENODEV;
 244         }
 245
 246         sa1111_writel(0, ps2if->base + PS2CR);
 247
 248         return ret;
 249 }
 250
 251 /*
 252  * Add one device to this driver.
 253  */
 254 static int ps2_probe(struct sa1111_dev *dev)
 255 {
 256         struct ps2if *ps2if;
 257         struct serio *serio;
 258         int ret;
 259
 260         ps2if = kzalloc(sizeof(struct ps2if), GFP_KERNEL);
 261         serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
 262         if (!ps2if || !serio) {
 263                 ret = -ENOMEM;
 264                 goto free;
 265         }
 266
 267
 268         serio->id.type          = SERIO_8042;
 269         serio->write            = ps2_write;
 270         serio->open             = ps2_open;
 271         serio->close            = ps2_close;
 272         strlcpy(serio->name, dev_name(&dev->dev), sizeof(serio->name));
 273         strlcpy(serio->phys, dev_name(&dev->dev), sizeof(serio->phys));
 274         serio->port_data        = ps2if;
 275         serio->dev.parent       = &dev->dev;
 276         ps2if->io               = serio;
 277         ps2if->dev              = dev;
 278         sa1111_set_drvdata(dev, ps2if);
 279
 280         spin_lock_init(&ps2if->lock);
 281
 282         /*
 283          * Request the physical region for this PS2 port.
 284          */
 285         if (!request_mem_region(dev->res.start,
 286                                 dev->res.end - dev->res.start + 1,
 287                                 SA1111_DRIVER_NAME(dev))) {
 288                 ret = -EBUSY;
 289                 goto free;
 290         }
 291
 292         /*
 293          * Our parent device has already mapped the region.
 294          */
 295         ps2if->base = dev->mapbase;
 296
 297         sa1111_enable_device(ps2if->dev);
 298
 299         /* Incoming clock is 8MHz */
 300         sa1111_writel(0, ps2if->base + PS2CLKDIV);
 301         sa1111_writel(127, ps2if->base + PS2PRECNT);
 302
 303         /*
 304          * Flush any pending input.
 305          */
 306         ps2_clear_input(ps2if);
 307
 308         /*
 309          * Test the keyboard interface.
 310          */
 311         ret = ps2_test(ps2if);
 312         if (ret)
 313                 goto out;
 314
 315         /*
 316          * Flush any pending input.
 317          */
 318         ps2_clear_input(ps2if);
 319
 320         sa1111_disable_device(ps2if->dev);
 321         serio_register_port(ps2if->io);
 322         return 0;
 323
 324  out:
 325         sa1111_disable_device(ps2if->dev);
 326         release_mem_region(dev->res.start, resource_size(&dev->res));
 327  free:
 328         sa1111_set_drvdata(dev, NULL);
 329         kfree(ps2if);
 330         kfree(serio);
 331         return ret;
 332 }
 333
 334 /*
 335  * Remove one device from this driver.
 336  */
 337 static int ps2_remove(struct sa1111_dev *dev)
 338 {
 339         struct ps2if *ps2if = sa1111_get_drvdata(dev);
 340
 341         serio_unregister_port(ps2if->io);
 342         release_mem_region(dev->res.start, resource_size(&dev->res));
 343         sa1111_set_drvdata(dev, NULL);
 344
 345         kfree(ps2if);
 346
 347         return 0;
 348 }
 349
 350 /*
 351  * Our device driver structure
 352  */
 353 static struct sa1111_driver ps2_driver = {
 354         .drv = {
 355                 .name   = "sa1111-ps2",
 356                 .owner  = THIS_MODULE,
 357         },
 358         .devid          = SA1111_DEVID_PS2,
 359         .probe          = ps2_probe,
 360         .remove         = ps2_remove,
 361 };
 362
 363 static int __init ps2_init(void)
 364 {
 365         return sa1111_driver_register(&ps2_driver);
 366 }
 367
 368 static void __exit ps2_exit(void)
 369 {
 370         sa1111_driver_unregister(&ps2_driver);
 371 }
 372
 373 module_init(ps2_init);
 374 module_exit(ps2_exit);
 375
 376 MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
 377 MODULE_DESCRIPTION("SA1111 PS2 controller driver");
 378 MODULE_LICENSE("GPL");