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