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 #include <asm/irq.h>
  24 #include <asm/system.h>
  25
  26 #include <asm/hardware/sa1111.h>
  27
  28 struct ps2if {
  29         struct serio            *io;
  30         struct sa1111_dev       *dev;
  31         void __iomem            *base;
  32         unsigned int            open;
  33         spinlock_t              lock;
  34         unsigned int            head;
  35         unsigned int            tail;
  36         unsigned char           buf[4];
  37 };
  38
  39 /*
  40  * Read all bytes waiting in the PS2 port.  There should be
  41  * at the most one, but we loop for safety.  If there was a
  42  * framing error, we have to manually clear the status.
  43  */
  44 static irqreturn_t ps2_rxint(int irq, void *dev_id, struct pt_regs *regs)
  45 {
  46         struct ps2if *ps2if = dev_id;
  47         unsigned int scancode, flag, status;
  48
  49         status = sa1111_readl(ps2if->base + SA1111_PS2STAT);
  50         while (status & PS2STAT_RXF) {
  51                 if (status & PS2STAT_STP)
  52                         sa1111_writel(PS2STAT_STP, ps2if->base + SA1111_PS2STAT);
  53
  54                 flag = (status & PS2STAT_STP ? SERIO_FRAME : 0) |
  55                        (status & PS2STAT_RXP ? 0 : SERIO_PARITY);
  56
  57                 scancode = sa1111_readl(ps2if->base + SA1111_PS2DATA) & 0xff;
  58
  59                 if (hweight8(scancode) & 1)
  60                         flag ^= SERIO_PARITY;
  61
  62                 serio_interrupt(ps2if->io, scancode, flag, regs);
  63
  64                 status = sa1111_readl(ps2if->base + SA1111_PS2STAT);
  65         }
  66
  67         return IRQ_HANDLED;
  68 }
  69
  70 /*
  71  * Completion of ps2 write
  72  */
  73 static irqreturn_t ps2_txint(int irq, void *dev_id, struct pt_regs *regs)
  74 {
  75         struct ps2if *ps2if = dev_id;
  76         unsigned int status;
  77
  78         spin_lock(&ps2if->lock);
  79         status = sa1111_readl(ps2if->base + SA1111_PS2STAT);
  80         if (ps2if->head == ps2if->tail) {
  81                 disable_irq(irq);
  82                 /* done */
  83         } else if (status & PS2STAT_TXE) {
  84                 sa1111_writel(ps2if->buf[ps2if->tail], ps2if->base + SA1111_PS2DATA);
  85                 ps2if->tail = (ps2if->tail + 1) & (sizeof(ps2if->buf) - 1);
  86         }
  87         spin_unlock(&ps2if->lock);
  88
  89         return IRQ_HANDLED;
  90 }
  91
  92 /*
  93  * Write a byte to the PS2 port.  We have to wait for the
  94  * port to indicate that the transmitter is empty.
  95  */
  96 static int ps2_write(struct serio *io, unsigned char val)
  97 {
  98         struct ps2if *ps2if = io->port_data;
  99         unsigned long flags;
 100         unsigned int head;
 101
 102         spin_lock_irqsave(&ps2if->lock, flags);
 103
 104         /*
 105          * If the TX register is empty, we can go straight out.
 106          */
 107         if (sa1111_readl(ps2if->base + SA1111_PS2STAT) & PS2STAT_TXE) {
 108                 sa1111_writel(val, ps2if->base + SA1111_PS2DATA);
 109         } else {
 110                 if (ps2if->head == ps2if->tail)
 111                         enable_irq(ps2if->dev->irq[1]);
 112                 head = (ps2if->head + 1) & (sizeof(ps2if->buf) - 1);
 113                 if (head != ps2if->tail) {
 114                         ps2if->buf[ps2if->head] = val;
 115                         ps2if->head = head;
 116                 }
 117         }
 118
 119         spin_unlock_irqrestore(&ps2if->lock, flags);
 120         return 0;
 121 }
 122
 123 static int ps2_open(struct serio *io)
 124 {
 125         struct ps2if *ps2if = io->port_data;
 126         int ret;
 127
 128         sa1111_enable_device(ps2if->dev);
 129
 130         ret = request_irq(ps2if->dev->irq[0], ps2_rxint, 0,
 131                           SA1111_DRIVER_NAME(ps2if->dev), ps2if);
 132         if (ret) {
 133                 printk(KERN_ERR "sa1111ps2: could not allocate IRQ%d: %d\n",
 134                         ps2if->dev->irq[0], ret);
 135                 return ret;
 136         }
 137
 138         ret = request_irq(ps2if->dev->irq[1], ps2_txint, 0,
 139                           SA1111_DRIVER_NAME(ps2if->dev), ps2if);
 140         if (ret) {
 141                 printk(KERN_ERR "sa1111ps2: could not allocate IRQ%d: %d\n",
 142                         ps2if->dev->irq[1], ret);
 143                 free_irq(ps2if->dev->irq[0], ps2if);
 144                 return ret;
 145         }
 146
 147         ps2if->open = 1;
 148
 149         enable_irq_wake(ps2if->dev->irq[0]);
 150
 151         sa1111_writel(PS2CR_ENA, ps2if->base + SA1111_PS2CR);
 152         return 0;
 153 }
 154
 155 static void ps2_close(struct serio *io)
 156 {
 157         struct ps2if *ps2if = io->port_data;
 158
 159         sa1111_writel(0, ps2if->base + SA1111_PS2CR);
 160
 161         disable_irq_wake(ps2if->dev->irq[0]);
 162
 163         ps2if->open = 0;
 164
 165         free_irq(ps2if->dev->irq[1], ps2if);
 166         free_irq(ps2if->dev->irq[0], ps2if);
 167
 168         sa1111_disable_device(ps2if->dev);
 169 }
 170
 171 /*
 172  * Clear the input buffer.
 173  */
 174 static void __init ps2_clear_input(struct ps2if *ps2if)
 175 {
 176         int maxread = 100;
 177
 178         while (maxread--) {
 179                 if ((sa1111_readl(ps2if->base + SA1111_PS2DATA) & 0xff) == 0xff)
 180                         break;
 181         }
 182 }
 183
 184 static inline unsigned int
 185 ps2_test_one(struct ps2if *ps2if, unsigned int mask)
 186 {
 187         unsigned int val;
 188
 189         sa1111_writel(PS2CR_ENA | mask, ps2if->base + SA1111_PS2CR);
 190
 191         udelay(2);
 192
 193         val = sa1111_readl(ps2if->base + SA1111_PS2STAT);
 194         return val & (PS2STAT_KBC | PS2STAT_KBD);
 195 }
 196
 197 /*
 198  * Test the keyboard interface.  We basically check to make sure that
 199  * we can drive each line to the keyboard independently of each other.
 200  */
 201 static int __init ps2_test(struct ps2if *ps2if)
 202 {
 203         unsigned int stat;
 204         int ret = 0;
 205
 206         stat = ps2_test_one(ps2if, PS2CR_FKC);
 207         if (stat != PS2STAT_KBD) {
 208                 printk("PS/2 interface test failed[1]: %02x\n", stat);
 209                 ret = -ENODEV;
 210         }
 211
 212         stat = ps2_test_one(ps2if, 0);
 213         if (stat != (PS2STAT_KBC | PS2STAT_KBD)) {
 214                 printk("PS/2 interface test failed[2]: %02x\n", stat);
 215                 ret = -ENODEV;
 216         }
 217
 218         stat = ps2_test_one(ps2if, PS2CR_FKD);
 219         if (stat != PS2STAT_KBC) {
 220                 printk("PS/2 interface test failed[3]: %02x\n", stat);
 221                 ret = -ENODEV;
 222         }
 223
 224         sa1111_writel(0, ps2if->base + SA1111_PS2CR);
 225
 226         return ret;
 227 }
 228
 229 /*
 230  * Add one device to this driver.
 231  */
 232 static int ps2_probe(struct sa1111_dev *dev)
 233 {
 234         struct ps2if *ps2if;
 235         struct serio *serio;
 236         int ret;
 237
 238         ps2if = kmalloc(sizeof(struct ps2if), GFP_KERNEL);
 239         serio = kmalloc(sizeof(struct serio), GFP_KERNEL);
 240         if (!ps2if || !serio) {
 241                 ret = -ENOMEM;
 242                 goto free;
 243         }
 244
 245         memset(ps2if, 0, sizeof(struct ps2if));
 246         memset(serio, 0, sizeof(struct serio));
 247
 248         serio->id.type          = SERIO_8042;
 249         serio->write            = ps2_write;
 250         serio->open             = ps2_open;
 251         serio->close            = ps2_close;
 252         strlcpy(serio->name, dev->dev.bus_id, sizeof(serio->name));
 253         strlcpy(serio->phys, dev->dev.bus_id, sizeof(serio->phys));
 254         serio->port_data        = ps2if;
 255         serio->dev.parent       = &dev->dev;
 256         ps2if->io               = serio;
 257         ps2if->dev              = dev;
 258         sa1111_set_drvdata(dev, ps2if);
 259
 260         spin_lock_init(&ps2if->lock);
 261
 262         /*
 263          * Request the physical region for this PS2 port.
 264          */
 265         if (!request_mem_region(dev->res.start,
 266                                 dev->res.end - dev->res.start + 1,
 267                                 SA1111_DRIVER_NAME(dev))) {
 268                 ret = -EBUSY;
 269                 goto free;
 270         }
 271
 272         /*
 273          * Our parent device has already mapped the region.
 274          */
 275         ps2if->base = dev->mapbase;
 276
 277         sa1111_enable_device(ps2if->dev);
 278
 279         /* Incoming clock is 8MHz */
 280         sa1111_writel(0, ps2if->base + SA1111_PS2CLKDIV);
 281         sa1111_writel(127, ps2if->base + SA1111_PS2PRECNT);
 282
 283         /*
 284          * Flush any pending input.
 285          */
 286         ps2_clear_input(ps2if);
 287
 288         /*
 289          * Test the keyboard interface.
 290          */
 291         ret = ps2_test(ps2if);
 292         if (ret)
 293                 goto out;
 294
 295         /*
 296          * Flush any pending input.
 297          */
 298         ps2_clear_input(ps2if);
 299
 300         sa1111_disable_device(ps2if->dev);
 301         serio_register_port(ps2if->io);
 302         return 0;
 303
 304  out:
 305         sa1111_disable_device(ps2if->dev);
 306         release_mem_region(dev->res.start,
 307                            dev->res.end - dev->res.start + 1);
 308  free:
 309         sa1111_set_drvdata(dev, NULL);
 310         kfree(ps2if);
 311         kfree(serio);
 312         return ret;
 313 }
 314
 315 /*
 316  * Remove one device from this driver.
 317  */
 318 static int ps2_remove(struct sa1111_dev *dev)
 319 {
 320         struct ps2if *ps2if = sa1111_get_drvdata(dev);
 321
 322         serio_unregister_port(ps2if->io);
 323         release_mem_region(dev->res.start,
 324                            dev->res.end - dev->res.start + 1);
 325         sa1111_set_drvdata(dev, NULL);
 326
 327         kfree(ps2if);
 328
 329         return 0;
 330 }
 331
 332 /*
 333  * Our device driver structure
 334  */
 335 static struct sa1111_driver ps2_driver = {
 336         .drv = {
 337                 .name   = "sa1111-ps2",
 338         },
 339         .devid          = SA1111_DEVID_PS2,
 340         .probe          = ps2_probe,
 341         .remove         = ps2_remove,
 342 };
 343
 344 static int __init ps2_init(void)
 345 {
 346         return sa1111_driver_register(&ps2_driver);
 347 }
 348
 349 static void __exit ps2_exit(void)
 350 {
 351         sa1111_driver_unregister(&ps2_driver);
 352 }
 353
 354 module_init(ps2_init);
 355 module_exit(ps2_exit);
 356
 357 MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
 358 MODULE_DESCRIPTION("SA1111 PS2 controller driver");
 359 MODULE_LICENSE("GPL");