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 struct ps2if {
  27         struct serio            *io;
  28         struct sa1111_dev       *dev;
  29         void __iomem            *base;
  30         unsigned int            open;
  31         spinlock_t              lock;
  32         unsigned int            head;
  33         unsigned int            tail;
  34         unsigned char           buf[4];
  35 };
  36
  37 /*
  38  * Read all bytes waiting in the PS2 port.  There should be
  39  * at the most one, but we loop for safety.  If there was a
  40  * framing error, we have to manually clear the status.
  41  */
  42 static irqreturn_t ps2_rxint(int irq, void *dev_id)
  43 {
  44         struct ps2if *ps2if = dev_id;
  45         unsigned int scancode, flag, status;
  46
  47         status = sa1111_readl(ps2if->base + SA1111_PS2STAT);
  48         while (status & PS2STAT_RXF) {
  49                 if (status & PS2STAT_STP)
  50                         sa1111_writel(PS2STAT_STP, ps2if->base + SA1111_PS2STAT);
  51
  52                 flag = (status & PS2STAT_STP ? SERIO_FRAME : 0) |
  53                        (status & PS2STAT_RXP ? 0 : SERIO_PARITY);
  54
  55                 scancode = sa1111_readl(ps2if->base + SA1111_PS2DATA) & 0xff;
  56
  57                 if (hweight8(scancode) & 1)
  58                         flag ^= SERIO_PARITY;
  59
  60                 serio_interrupt(ps2if->io, scancode, flag);
  61
  62                 status = sa1111_readl(ps2if->base + SA1111_PS2STAT);
  63         }
  64
  65         return IRQ_HANDLED;
  66 }
  67
  68 /*
  69  * Completion of ps2 write
  70  */
  71 static irqreturn_t ps2_txint(int irq, void *dev_id)
  72 {
  73         struct ps2if *ps2if = dev_id;
  74         unsigned int status;
  75
  76         spin_lock(&ps2if->lock);
  77         status = sa1111_readl(ps2if->base + SA1111_PS2STAT);
  78         if (ps2if->head == ps2if->tail) {
  79                 disable_irq_nosync(irq);
  80                 /* done */
  81         } else if (status & PS2STAT_TXE) {
  82                 sa1111_writel(ps2if->buf[ps2if->tail], ps2if->base + SA1111_PS2DATA);
  83                 ps2if->tail = (ps2if->tail + 1) & (sizeof(ps2if->buf) - 1);
  84         }
  85         spin_unlock(&ps2if->lock);
  86
  87         return IRQ_HANDLED;
  88 }
  89
  90 /*
  91  * Write a byte to the PS2 port.  We have to wait for the
  92  * port to indicate that the transmitter is empty.
  93  */
  94 static int ps2_write(struct serio *io, unsigned char val)
  95 {
  96         struct ps2if *ps2if = io->port_data;
  97         unsigned long flags;
  98         unsigned int head;
  99
 100         spin_lock_irqsave(&ps2if->lock, flags);
 101
 102         /*
 103          * If the TX register is empty, we can go straight out.
 104          */
 105         if (sa1111_readl(ps2if->base + SA1111_PS2STAT) & PS2STAT_TXE) {
 106                 sa1111_writel(val, ps2if->base + SA1111_PS2DATA);
 107         } else {
 108                 if (ps2if->head == ps2if->tail)
 109                         enable_irq(ps2if->dev->irq[1]);
 110                 head = (ps2if->head + 1) & (sizeof(ps2if->buf) - 1);
 111                 if (head != ps2if->tail) {
 112                         ps2if->buf[ps2if->head] = val;
 113                         ps2if->head = head;
 114                 }
 115         }
 116
 117         spin_unlock_irqrestore(&ps2if->lock, flags);
 118         return 0;
 119 }
 120
 121 static int ps2_open(struct serio *io)
 122 {
 123         struct ps2if *ps2if = io->port_data;
 124         int ret;
 125
 126         sa1111_enable_device(ps2if->dev);
 127
 128         ret = request_irq(ps2if->dev->irq[0], ps2_rxint, 0,
 129                           SA1111_DRIVER_NAME(ps2if->dev), ps2if);
 130         if (ret) {
 131                 printk(KERN_ERR "sa1111ps2: could not allocate IRQ%d: %d\n",
 132                         ps2if->dev->irq[0], ret);
 133                 return ret;
 134         }
 135
 136         ret = request_irq(ps2if->dev->irq[1], ps2_txint, 0,
 137                           SA1111_DRIVER_NAME(ps2if->dev), ps2if);
 138         if (ret) {
 139                 printk(KERN_ERR "sa1111ps2: could not allocate IRQ%d: %d\n",
 140                         ps2if->dev->irq[1], ret);
 141                 free_irq(ps2if->dev->irq[0], ps2if);
 142                 return ret;
 143         }
 144
 145         ps2if->open = 1;
 146
 147         enable_irq_wake(ps2if->dev->irq[0]);
 148
 149         sa1111_writel(PS2CR_ENA, ps2if->base + SA1111_PS2CR);
 150         return 0;
 151 }
 152
 153 static void ps2_close(struct serio *io)
 154 {
 155         struct ps2if *ps2if = io->port_data;
 156
 157         sa1111_writel(0, ps2if->base + SA1111_PS2CR);
 158
 159         disable_irq_wake(ps2if->dev->irq[0]);
 160
 161         ps2if->open = 0;
 162
 163         free_irq(ps2if->dev->irq[1], ps2if);
 164         free_irq(ps2if->dev->irq[0], ps2if);
 165
 166         sa1111_disable_device(ps2if->dev);
 167 }
 168
 169 /*
 170  * Clear the input buffer.
 171  */
 172 static void __devinit ps2_clear_input(struct ps2if *ps2if)
 173 {
 174         int maxread = 100;
 175
 176         while (maxread--) {
 177                 if ((sa1111_readl(ps2if->base + SA1111_PS2DATA) & 0xff) == 0xff)
 178                         break;
 179         }
 180 }
 181
 182 static unsigned int __devinit ps2_test_one(struct ps2if *ps2if,
 183                                            unsigned int mask)
 184 {
 185         unsigned int val;
 186
 187         sa1111_writel(PS2CR_ENA | mask, ps2if->base + SA1111_PS2CR);
 188
 189         udelay(2);
 190
 191         val = sa1111_readl(ps2if->base + SA1111_PS2STAT);
 192         return val & (PS2STAT_KBC | PS2STAT_KBD);
 193 }
 194
 195 /*
 196  * Test the keyboard interface.  We basically check to make sure that
 197  * we can drive each line to the keyboard independently of each other.
 198  */
 199 static int __devinit ps2_test(struct ps2if *ps2if)
 200 {
 201         unsigned int stat;
 202         int ret = 0;
 203
 204         stat = ps2_test_one(ps2if, PS2CR_FKC);
 205         if (stat != PS2STAT_KBD) {
 206                 printk("PS/2 interface test failed[1]: %02x\n", stat);
 207                 ret = -ENODEV;
 208         }
 209
 210         stat = ps2_test_one(ps2if, 0);
 211         if (stat != (PS2STAT_KBC | PS2STAT_KBD)) {
 212                 printk("PS/2 interface test failed[2]: %02x\n", stat);
 213                 ret = -ENODEV;
 214         }
 215
 216         stat = ps2_test_one(ps2if, PS2CR_FKD);
 217         if (stat != PS2STAT_KBC) {
 218                 printk("PS/2 interface test failed[3]: %02x\n", stat);
 219                 ret = -ENODEV;
 220         }
 221
 222         sa1111_writel(0, ps2if->base + SA1111_PS2CR);
 223
 224         return ret;
 225 }
 226
 227 /*
 228  * Add one device to this driver.
 229  */
 230 static int __devinit ps2_probe(struct sa1111_dev *dev)
 231 {
 232         struct ps2if *ps2if;
 233         struct serio *serio;
 234         int ret;
 235
 236         ps2if = kzalloc(sizeof(struct ps2if), GFP_KERNEL);
 237         serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
 238         if (!ps2if || !serio) {
 239                 ret = -ENOMEM;
 240                 goto free;
 241         }
 242
 243
 244         serio->id.type          = SERIO_8042;
 245         serio->write            = ps2_write;
 246         serio->open             = ps2_open;
 247         serio->close            = ps2_close;
 248         strlcpy(serio->name, dev_name(&dev->dev), sizeof(serio->name));
 249         strlcpy(serio->phys, dev_name(&dev->dev), sizeof(serio->phys));
 250         serio->port_data        = ps2if;
 251         serio->dev.parent       = &dev->dev;
 252         ps2if->io               = serio;
 253         ps2if->dev              = dev;
 254         sa1111_set_drvdata(dev, ps2if);
 255
 256         spin_lock_init(&ps2if->lock);
 257
 258         /*
 259          * Request the physical region for this PS2 port.
 260          */
 261         if (!request_mem_region(dev->res.start,
 262                                 dev->res.end - dev->res.start + 1,
 263                                 SA1111_DRIVER_NAME(dev))) {
 264                 ret = -EBUSY;
 265                 goto free;
 266         }
 267
 268         /*
 269          * Our parent device has already mapped the region.
 270          */
 271         ps2if->base = dev->mapbase;
 272
 273         sa1111_enable_device(ps2if->dev);
 274
 275         /* Incoming clock is 8MHz */
 276         sa1111_writel(0, ps2if->base + SA1111_PS2CLKDIV);
 277         sa1111_writel(127, ps2if->base + SA1111_PS2PRECNT);
 278
 279         /*
 280          * Flush any pending input.
 281          */
 282         ps2_clear_input(ps2if);
 283
 284         /*
 285          * Test the keyboard interface.
 286          */
 287         ret = ps2_test(ps2if);
 288         if (ret)
 289                 goto out;
 290
 291         /*
 292          * Flush any pending input.
 293          */
 294         ps2_clear_input(ps2if);
 295
 296         sa1111_disable_device(ps2if->dev);
 297         serio_register_port(ps2if->io);
 298         return 0;
 299
 300  out:
 301         sa1111_disable_device(ps2if->dev);
 302         release_mem_region(dev->res.start, resource_size(&dev->res));
 303  free:
 304         sa1111_set_drvdata(dev, NULL);
 305         kfree(ps2if);
 306         kfree(serio);
 307         return ret;
 308 }
 309
 310 /*
 311  * Remove one device from this driver.
 312  */
 313 static int __devexit ps2_remove(struct sa1111_dev *dev)
 314 {
 315         struct ps2if *ps2if = sa1111_get_drvdata(dev);
 316
 317         serio_unregister_port(ps2if->io);
 318         release_mem_region(dev->res.start, resource_size(&dev->res));
 319         sa1111_set_drvdata(dev, NULL);
 320
 321         kfree(ps2if);
 322
 323         return 0;
 324 }
 325
 326 /*
 327  * Our device driver structure
 328  */
 329 static struct sa1111_driver ps2_driver = {
 330         .drv = {
 331                 .name   = "sa1111-ps2",
 332         },
 333         .devid          = SA1111_DEVID_PS2,
 334         .probe          = ps2_probe,
 335         .remove         = __devexit_p(ps2_remove),
 336 };
 337
 338 static int __init ps2_init(void)
 339 {
 340         return sa1111_driver_register(&ps2_driver);
 341 }
 342
 343 static void __exit ps2_exit(void)
 344 {
 345         sa1111_driver_unregister(&ps2_driver);
 346 }
 347
 348 module_init(ps2_init);
 349 module_exit(ps2_exit);
 350
 351 MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
 352 MODULE_DESCRIPTION("SA1111 PS2 controller driver");
 353 MODULE_LICENSE("GPL");