drivers/input/serio/altera_ps2.c

   1 /*
   2  * Altera University Program PS2 controller driver
   3  *
   4  * Copyright (C) 2008 Thomas Chou <thomas@wytron.com.tw>
   5  *
   6  * Based on sa1111ps2.c, which is:
   7  * Copyright (C) 2002 Russell King
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  */
  13
  14 #include <linux/module.h>
  15 #include <linux/init.h>
  16 #include <linux/input.h>
  17 #include <linux/serio.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/io.h>
  21
  22 #define DRV_NAME "altera_ps2"
  23
  24 struct ps2if {
  25         struct serio *io;
  26         struct resource *iomem_res;
  27         void __iomem *base;
  28         unsigned irq;
  29 };
  30
  31 /*
  32  * Read all bytes waiting in the PS2 port.  There should be
  33  * at the most one, but we loop for safety.
  34  */
  35 static irqreturn_t altera_ps2_rxint(int irq, void *dev_id)
  36 {
  37         struct ps2if *ps2if = dev_id;
  38         unsigned int status;
  39         int handled = IRQ_NONE;
  40
  41         while ((status = readl(ps2if->base)) & 0xffff0000) {
  42                 serio_interrupt(ps2if->io, status & 0xff, 0);
  43                 handled = IRQ_HANDLED;
  44         }
  45
  46         return handled;
  47 }
  48
  49 /*
  50  * Write a byte to the PS2 port.
  51  */
  52 static int altera_ps2_write(struct serio *io, unsigned char val)
  53 {
  54         struct ps2if *ps2if = io->port_data;
  55
  56         writel(val, ps2if->base);
  57         return 0;
  58 }
  59
  60 static int altera_ps2_open(struct serio *io)
  61 {
  62         struct ps2if *ps2if = io->port_data;
  63
  64         /* clear fifo */
  65         while (readl(ps2if->base) & 0xffff0000)
  66                 /* empty */;
  67
  68         writel(1, ps2if->base + 4); /* enable rx irq */
  69         return 0;
  70 }
  71
  72 static void altera_ps2_close(struct serio *io)
  73 {
  74         struct ps2if *ps2if = io->port_data;
  75
  76         writel(0, ps2if->base); /* disable rx irq */
  77 }
  78
  79 /*
  80  * Add one device to this driver.
  81  */
  82 static int __devinit altera_ps2_probe(struct platform_device *pdev)
  83 {
  84         struct ps2if *ps2if;
  85         struct serio *serio;
  86         int error, irq;
  87
  88         ps2if = kzalloc(sizeof(struct ps2if), GFP_KERNEL);
  89         serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
  90         if (!ps2if || !serio) {
  91                 error = -ENOMEM;
  92                 goto err_free_mem;
  93         }
  94
  95         serio->id.type          = SERIO_8042;
  96         serio->write            = altera_ps2_write;
  97         serio->open             = altera_ps2_open;
  98         serio->close            = altera_ps2_close;
  99         strlcpy(serio->name, dev_name(&pdev->dev), sizeof(serio->name));
 100         strlcpy(serio->phys, dev_name(&pdev->dev), sizeof(serio->phys));
 101         serio->port_data        = ps2if;
 102         serio->dev.parent       = &pdev->dev;
 103         ps2if->io               = serio;
 104
 105         ps2if->iomem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 106         if (ps2if->iomem_res == NULL) {
 107                 error = -ENOENT;
 108                 goto err_free_mem;
 109         }
 110
 111
 112         irq = platform_get_irq(pdev, 0);
 113         if (irq < 0) {
 114                 error = -ENXIO;
 115                 goto err_free_mem;
 116         }
 117         ps2if->irq = irq;
 118
 119         if (!request_mem_region(ps2if->iomem_res->start,
 120                                 resource_size(ps2if->iomem_res), pdev->name)) {
 121                 error = -EBUSY;
 122                 goto err_free_mem;
 123         }
 124
 125         ps2if->base = ioremap(ps2if->iomem_res->start,
 126                               resource_size(ps2if->iomem_res));
 127         if (!ps2if->base) {
 128                 error = -ENOMEM;
 129                 goto err_free_res;
 130         }
 131
 132         error = request_irq(ps2if->irq, altera_ps2_rxint, 0, pdev->name, ps2if);
 133         if (error) {
 134                 dev_err(&pdev->dev, "could not allocate IRQ %d: %d\n",
 135                         ps2if->irq, error);
 136                 goto err_unmap;
 137         }
 138
 139         dev_info(&pdev->dev, "base %p, irq %d\n", ps2if->base, ps2if->irq);
 140
 141         serio_register_port(ps2if->io);
 142         platform_set_drvdata(pdev, ps2if);
 143
 144         return 0;
 145
 146  err_unmap:
 147         iounmap(ps2if->base);
 148  err_free_res:
 149         release_mem_region(ps2if->iomem_res->start,
 150                            resource_size(ps2if->iomem_res));
 151  err_free_mem:
 152         kfree(ps2if);
 153         kfree(serio);
 154         return error;
 155 }
 156
 157 /*
 158  * Remove one device from this driver.
 159  */
 160 static int __devexit altera_ps2_remove(struct platform_device *pdev)
 161 {
 162         struct ps2if *ps2if = platform_get_drvdata(pdev);
 163
 164         platform_set_drvdata(pdev, NULL);
 165         serio_unregister_port(ps2if->io);
 166         free_irq(ps2if->irq, ps2if);
 167         iounmap(ps2if->base);
 168         release_mem_region(ps2if->iomem_res->start,
 169                            resource_size(ps2if->iomem_res));
 170         kfree(ps2if);
 171
 172         return 0;
 173 }
 174
 175 /*
 176  * Our device driver structure
 177  */
 178 static struct platform_driver altera_ps2_driver = {
 179         .probe          = altera_ps2_probe,
 180         .remove         = __devexit_p(altera_ps2_remove),
 181         .driver = {
 182                 .name   = DRV_NAME,
 183                 .owner  = THIS_MODULE,
 184         },
 185 };
 186
 187 static int __init altera_ps2_init(void)
 188 {
 189         return platform_driver_register(&altera_ps2_driver);
 190 }
 191
 192 static void __exit altera_ps2_exit(void)
 193 {
 194         platform_driver_unregister(&altera_ps2_driver);
 195 }
 196
 197 module_init(altera_ps2_init);
 198 module_exit(altera_ps2_exit);
 199
 200 MODULE_DESCRIPTION("Altera University Program PS2 controller driver");
 201 MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
 202 MODULE_LICENSE("GPL");
 203 MODULE_ALIAS("platform:" DRV_NAME);