drivers/input/serio/xilinx_ps2.c

   1 /*
   2  * Xilinx XPS PS/2 device driver
   3  *
   4  * (c) 2005 MontaVista Software, Inc.
   5  * (c) 2008 Xilinx, Inc.
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License as published by the
   9  * Free Software Foundation; either version 2 of the License, or (at your
  10  * option) any later version.
  11  *
  12  * You should have received a copy of the GNU General Public License along
  13  * with this program; if not, write to the Free Software Foundation, Inc.,
  14  * 675 Mass Ave, Cambridge, MA 02139, USA.
  15  */
  16
  17
  18 #include <linux/module.h>
  19 #include <linux/serio.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/errno.h>
  22 #include <linux/init.h>
  23 #include <linux/list.h>
  24 #include <linux/io.h>
  25
  26 #include <linux/of_device.h>
  27 #include <linux/of_platform.h>
  28
  29 #define DRIVER_NAME             "xilinx_ps2"
  30
  31 /* Register offsets for the xps2 device */
  32 #define XPS2_SRST_OFFSET        0x00000000 /* Software Reset register */
  33 #define XPS2_STATUS_OFFSET      0x00000004 /* Status register */
  34 #define XPS2_RX_DATA_OFFSET     0x00000008 /* Receive Data register */
  35 #define XPS2_TX_DATA_OFFSET     0x0000000C /* Transmit Data register */
  36 #define XPS2_GIER_OFFSET        0x0000002C /* Global Interrupt Enable reg */
  37 #define XPS2_IPISR_OFFSET       0x00000030 /* Interrupt Status register */
  38 #define XPS2_IPIER_OFFSET       0x00000038 /* Interrupt Enable register */
  39
  40 /* Reset Register Bit Definitions */
  41 #define XPS2_SRST_RESET         0x0000000A /* Software Reset  */
  42
  43 /* Status Register Bit Positions */
  44 #define XPS2_STATUS_RX_FULL     0x00000001 /* Receive Full  */
  45 #define XPS2_STATUS_TX_FULL     0x00000002 /* Transmit Full  */
  46
  47 /* Bit definitions for ISR/IER registers. Both the registers have the same bit
  48  * definitions and are only defined once. */
  49 #define XPS2_IPIXR_WDT_TOUT     0x00000001 /* Watchdog Timeout Interrupt */
  50 #define XPS2_IPIXR_TX_NOACK     0x00000002 /* Transmit No ACK Interrupt */
  51 #define XPS2_IPIXR_TX_ACK       0x00000004 /* Transmit ACK (Data) Interrupt */
  52 #define XPS2_IPIXR_RX_OVF       0x00000008 /* Receive Overflow Interrupt */
  53 #define XPS2_IPIXR_RX_ERR       0x00000010 /* Receive Error Interrupt */
  54 #define XPS2_IPIXR_RX_FULL      0x00000020 /* Receive Data Interrupt */
  55
  56 /* Mask for all the Transmit Interrupts */
  57 #define XPS2_IPIXR_TX_ALL       (XPS2_IPIXR_TX_NOACK | XPS2_IPIXR_TX_ACK)
  58
  59 /* Mask for all the Receive Interrupts */
  60 #define XPS2_IPIXR_RX_ALL       (XPS2_IPIXR_RX_OVF | XPS2_IPIXR_RX_ERR |  \
  61                                         XPS2_IPIXR_RX_FULL)
  62
  63 /* Mask for all the Interrupts */
  64 #define XPS2_IPIXR_ALL          (XPS2_IPIXR_TX_ALL | XPS2_IPIXR_RX_ALL |  \
  65                                         XPS2_IPIXR_WDT_TOUT)
  66
  67 /* Global Interrupt Enable mask */
  68 #define XPS2_GIER_GIE_MASK      0x80000000
  69
  70 struct xps2data {
  71         int irq;
  72         u32 phys_addr;
  73         u32 remap_size;
  74         spinlock_t lock;
  75         u8 rxb;                         /* Rx buffer */
  76         void __iomem *base_address;     /* virt. address of control registers */
  77         unsigned int dfl;
  78         struct serio serio;             /* serio */
  79 };
  80
  81 /************************************/
  82 /* XPS PS/2 data transmission calls */
  83 /************************************/
  84
  85 /*
  86  * xps2_recv() will attempt to receive a byte of data from the PS/2 port.
  87  */
  88 static int xps2_recv(struct xps2data *drvdata, u8 *byte)
  89 {
  90         u32 sr;
  91         int status = -1;
  92
  93         /* If there is data available in the PS/2 receiver, read it */
  94         sr = in_be32(drvdata->base_address + XPS2_STATUS_OFFSET);
  95         if (sr & XPS2_STATUS_RX_FULL) {
  96                 *byte = in_be32(drvdata->base_address + XPS2_RX_DATA_OFFSET);
  97                 status = 0;
  98         }
  99
 100         return status;
 101 }
 102
 103 /*********************/
 104 /* Interrupt handler */
 105 /*********************/
 106 static irqreturn_t xps2_interrupt(int irq, void *dev_id)
 107 {
 108         struct xps2data *drvdata = dev_id;
 109         u32 intr_sr;
 110         u8 c;
 111         int status;
 112
 113         /* Get the PS/2 interrupts and clear them */
 114         intr_sr = in_be32(drvdata->base_address + XPS2_IPISR_OFFSET);
 115         out_be32(drvdata->base_address + XPS2_IPISR_OFFSET, intr_sr);
 116
 117         /* Check which interrupt is active */
 118         if (intr_sr & XPS2_IPIXR_RX_OVF)
 119                 printk(KERN_WARNING "%s: receive overrun error\n",
 120                         drvdata->serio.name);
 121
 122         if (intr_sr & XPS2_IPIXR_RX_ERR)
 123                 drvdata->dfl |= SERIO_PARITY;
 124
 125         if (intr_sr & (XPS2_IPIXR_TX_NOACK | XPS2_IPIXR_WDT_TOUT))
 126                 drvdata->dfl |= SERIO_TIMEOUT;
 127
 128         if (intr_sr & XPS2_IPIXR_RX_FULL) {
 129                 status = xps2_recv(drvdata, &drvdata->rxb);
 130
 131                 /* Error, if a byte is not received */
 132                 if (status) {
 133                         printk(KERN_ERR
 134                                 "%s: wrong rcvd byte count (%d)\n",
 135                                 drvdata->serio.name, status);
 136                 } else {
 137                         c = drvdata->rxb;
 138                         serio_interrupt(&drvdata->serio, c, drvdata->dfl);
 139                         drvdata->dfl = 0;
 140                 }
 141         }
 142
 143         if (intr_sr & XPS2_IPIXR_TX_ACK)
 144                 drvdata->dfl = 0;
 145
 146         return IRQ_HANDLED;
 147 }
 148
 149 /*******************/
 150 /* serio callbacks */
 151 /*******************/
 152
 153 /*
 154  * sxps2_write() sends a byte out through the PS/2 interface.
 155  */
 156 static int sxps2_write(struct serio *pserio, unsigned char c)
 157 {
 158         struct xps2data *drvdata = pserio->port_data;
 159         unsigned long flags;
 160         u32 sr;
 161         int status = -1;
 162
 163         spin_lock_irqsave(&drvdata->lock, flags);
 164
 165         /* If the PS/2 transmitter is empty send a byte of data */
 166         sr = in_be32(drvdata->base_address + XPS2_STATUS_OFFSET);
 167         if (!(sr & XPS2_STATUS_TX_FULL)) {
 168                 out_be32(drvdata->base_address + XPS2_TX_DATA_OFFSET, c);
 169                 status = 0;
 170         }
 171
 172         spin_unlock_irqrestore(&drvdata->lock, flags);
 173
 174         return status;
 175 }
 176
 177 /*
 178  * sxps2_open() is called when a port is open by the higher layer.
 179  */
 180 static int sxps2_open(struct serio *pserio)
 181 {
 182         struct xps2data *drvdata = pserio->port_data;
 183         int retval;
 184
 185         retval = request_irq(drvdata->irq, &xps2_interrupt, 0,
 186                                 DRIVER_NAME, drvdata);
 187         if (retval) {
 188                 printk(KERN_ERR
 189                         "%s: Couldn't allocate interrupt %d\n",
 190                         drvdata->serio.name, drvdata->irq);
 191                 return retval;
 192         }
 193
 194         /* start reception by enabling the interrupts */
 195         out_be32(drvdata->base_address + XPS2_GIER_OFFSET, XPS2_GIER_GIE_MASK);
 196         out_be32(drvdata->base_address + XPS2_IPIER_OFFSET, XPS2_IPIXR_RX_ALL);
 197         (void)xps2_recv(drvdata, &drvdata->rxb);
 198
 199         return 0;               /* success */
 200 }
 201
 202 /*
 203  * sxps2_close() frees the interrupt.
 204  */
 205 static void sxps2_close(struct serio *pserio)
 206 {
 207         struct xps2data *drvdata = pserio->port_data;
 208
 209         /* Disable the PS2 interrupts */
 210         out_be32(drvdata->base_address + XPS2_GIER_OFFSET, 0x00);
 211         out_be32(drvdata->base_address + XPS2_IPIER_OFFSET, 0x00);
 212         free_irq(drvdata->irq, drvdata);
 213 }
 214
 215 /*********************/
 216 /* Device setup code */
 217 /*********************/
 218
 219 static int xps2_setup(struct device *dev, struct resource *regs_res,
 220                       struct resource *irq_res)
 221 {
 222         struct xps2data *drvdata;
 223         struct serio *serio;
 224         unsigned long remap_size;
 225         int retval;
 226
 227         if (!dev)
 228                 return -EINVAL;
 229
 230         if (!regs_res || !irq_res) {
 231                 dev_err(dev, "IO resource(s) not found\n");
 232                 return -EINVAL;
 233         }
 234
 235         drvdata = kzalloc(sizeof(struct xps2data), GFP_KERNEL);
 236         if (!drvdata) {
 237                 dev_err(dev, "Couldn't allocate device private record\n");
 238                 return -ENOMEM;
 239         }
 240
 241         dev_set_drvdata(dev, drvdata);
 242
 243         spin_lock_init(&drvdata->lock);
 244         drvdata->irq = irq_res->start;
 245
 246         remap_size = regs_res->end - regs_res->start + 1;
 247         if (!request_mem_region(regs_res->start, remap_size, DRIVER_NAME)) {
 248                 dev_err(dev, "Couldn't lock memory region at 0x%08X\n",
 249                         (unsigned int)regs_res->start);
 250                 retval = -EBUSY;
 251                 goto failed1;
 252         }
 253
 254         /* Fill in configuration data and add them to the list */
 255         drvdata->phys_addr = regs_res->start;
 256         drvdata->remap_size = remap_size;
 257         drvdata->base_address = ioremap(regs_res->start, remap_size);
 258         if (drvdata->base_address == NULL) {
 259                 dev_err(dev, "Couldn't ioremap memory at 0x%08X\n",
 260                         (unsigned int)regs_res->start);
 261                 retval = -EFAULT;
 262                 goto failed2;
 263         }
 264
 265         /* Disable all the interrupts, just in case */
 266         out_be32(drvdata->base_address + XPS2_IPIER_OFFSET, 0);
 267
 268         /* Reset the PS2 device and abort any current transaction, to make sure
 269          * we have the PS2 in a good state */
 270         out_be32(drvdata->base_address + XPS2_SRST_OFFSET, XPS2_SRST_RESET);
 271
 272         dev_info(dev, "Xilinx PS2 at 0x%08X mapped to 0x%p, irq=%d\n",
 273                 drvdata->phys_addr, drvdata->base_address, drvdata->irq);
 274
 275         serio = &drvdata->serio;
 276         serio->id.type = SERIO_8042;
 277         serio->write = sxps2_write;
 278         serio->open = sxps2_open;
 279         serio->close = sxps2_close;
 280         serio->port_data = drvdata;
 281         serio->dev.parent = dev;
 282         snprintf(serio->name, sizeof(serio->name),
 283                  "Xilinx XPS PS/2 at %08X", drvdata->phys_addr);
 284         snprintf(serio->phys, sizeof(serio->phys),
 285                  "xilinxps2/serio at %08X", drvdata->phys_addr);
 286         serio_register_port(serio);
 287
 288         return 0;               /* success */
 289
 290 failed2:
 291         release_mem_region(regs_res->start, remap_size);
 292 failed1:
 293         kfree(drvdata);
 294         dev_set_drvdata(dev, NULL);
 295
 296         return retval;
 297 }
 298
 299 /***************************/
 300 /* OF Platform Bus Support */
 301 /***************************/
 302
 303 static int __devinit xps2_of_probe(struct of_device *ofdev, const struct
 304                                    of_device_id * match)
 305 {
 306         struct resource r_irq; /* Interrupt resources */
 307         struct resource r_mem; /* IO mem resources */
 308         int rc = 0;
 309
 310         printk(KERN_INFO "Device Tree Probing \'%s\'\n",
 311                         ofdev->node->name);
 312
 313         /* Get iospace for the device */
 314         rc = of_address_to_resource(ofdev->node, 0, &r_mem);
 315         if (rc) {
 316                 dev_err(&ofdev->dev, "invalid address\n");
 317                 return rc;
 318         }
 319
 320         /* Get IRQ for the device */
 321         rc = of_irq_to_resource(ofdev->node, 0, &r_irq);
 322         if (rc == NO_IRQ) {
 323                 dev_err(&ofdev->dev, "no IRQ found\n");
 324                 return rc;
 325         }
 326
 327         return xps2_setup(&ofdev->dev, &r_mem, &r_irq);
 328 }
 329
 330 static int __devexit xps2_of_remove(struct of_device *of_dev)
 331 {
 332         struct device *dev = &of_dev->dev;
 333         struct xps2data *drvdata;
 334
 335         if (!dev)
 336                 return -EINVAL;
 337
 338         drvdata = dev_get_drvdata(dev);
 339
 340         serio_unregister_port(&drvdata->serio);
 341         iounmap(drvdata->base_address);
 342         release_mem_region(drvdata->phys_addr, drvdata->remap_size);
 343         kfree(drvdata);
 344
 345         dev_set_drvdata(dev, NULL);
 346
 347         return 0;               /* success */
 348 }
 349
 350 /* Match table for of_platform binding */
 351 static struct of_device_id xps2_of_match[] __devinitdata = {
 352         { .compatible = "xlnx,xps-ps2-1.00.a", },
 353         { /* end of list */ },
 354 };
 355 MODULE_DEVICE_TABLE(of, xps2_of_match);
 356
 357 static struct of_platform_driver xps2_of_driver = {
 358         .name           = DRIVER_NAME,
 359         .match_table    = xps2_of_match,
 360         .probe          = xps2_of_probe,
 361         .remove         = __devexit_p(xps2_of_remove),
 362 };
 363
 364 static int __init xps2_init(void)
 365 {
 366         return of_register_platform_driver(&xps2_of_driver);
 367 }
 368
 369 static void __exit xps2_cleanup(void)
 370 {
 371         of_unregister_platform_driver(&xps2_of_driver);
 372 }
 373
 374 module_init(xps2_init);
 375 module_exit(xps2_cleanup);
 376
 377 MODULE_AUTHOR("Xilinx, Inc.");
 378 MODULE_DESCRIPTION("Xilinx XPS PS/2 driver");
 379 MODULE_LICENSE("GPL");
 380