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/input.h>
  16 #include <linux/serio.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/platform_device.h>
  19 #include <linux/io.h>
  20 #include <linux/slab.h>
  21 #include <linux/of.h>
  22
  23 #define DRV_NAME "altera_ps2"
  24
  25 struct ps2if {
  26         struct serio *io;
  27         struct resource *iomem_res;
  28         void __iomem *base;
  29         unsigned irq;
  30 };
  31
  32 /*
  33  * Read all bytes waiting in the PS2 port.  There should be
  34  * at the most one, but we loop for safety.
  35  */
  36 static irqreturn_t altera_ps2_rxint(int irq, void *dev_id)
  37 {
  38         struct ps2if *ps2if = dev_id;
  39         unsigned int status;
  40         int handled = IRQ_NONE;
  41
  42         while ((status = readl(ps2if->base)) & 0xffff0000) {
  43                 serio_interrupt(ps2if->io, status & 0xff, 0);
  44                 handled = IRQ_HANDLED;
  45         }
  46
  47         return handled;
  48 }
  49
  50 /*
  51  * Write a byte to the PS2 port.
  52  */
  53 static int altera_ps2_write(struct serio *io, unsigned char val)
  54 {
  55         struct ps2if *ps2if = io->port_data;
  56
  57         writel(val, ps2if->base);
  58         return 0;
  59 }
  60
  61 static int altera_ps2_open(struct serio *io)
  62 {
  63         struct ps2if *ps2if = io->port_data;
  64
  65         /* clear fifo */
  66         while (readl(ps2if->base) & 0xffff0000)
  67                 /* empty */;
  68
  69         writel(1, ps2if->base + 4); /* enable rx irq */
  70         return 0;
  71 }
  72
  73 static void altera_ps2_close(struct serio *io)
  74 {
  75         struct ps2if *ps2if = io->port_data;
  76
  77         writel(0, ps2if->base); /* disable rx irq */
  78 }
  79
  80 /*
  81  * Add one device to this driver.
  82  */
  83 static int altera_ps2_probe(struct platform_device *pdev)
  84 {
  85         struct ps2if *ps2if;
  86         struct serio *serio;
  87         int error, irq;
  88
  89         ps2if = kzalloc(sizeof(struct ps2if), GFP_KERNEL);
  90         serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
  91         if (!ps2if || !serio) {
  92                 error = -ENOMEM;
  93                 goto err_free_mem;
  94         }
  95
  96         serio->id.type          = SERIO_8042;
  97         serio->write            = altera_ps2_write;
  98         serio->open             = altera_ps2_open;
  99         serio->close            = altera_ps2_close;
 100         strlcpy(serio->name, dev_name(&pdev->dev), sizeof(serio->name));
 101         strlcpy(serio->phys, dev_name(&pdev->dev), sizeof(serio->phys));
 102         serio->port_data        = ps2if;
 103         serio->dev.parent       = &pdev->dev;
 104         ps2if->io               = serio;
 105
 106         ps2if->iomem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 107         if (ps2if->iomem_res == NULL) {
 108                 error = -ENOENT;
 109                 goto err_free_mem;
 110         }
 111
 112
 113         irq = platform_get_irq(pdev, 0);
 114         if (irq < 0) {
 115                 error = -ENXIO;
 116                 goto err_free_mem;
 117         }
 118         ps2if->irq = irq;
 119
 120         if (!request_mem_region(ps2if->iomem_res->start,
 121                                 resource_size(ps2if->iomem_res), pdev->name)) {
 122                 error = -EBUSY;
 123                 goto err_free_mem;
 124         }
 125
 126         ps2if->base = ioremap(ps2if->iomem_res->start,
 127                               resource_size(ps2if->iomem_res));
 128         if (!ps2if->base) {
 129                 error = -ENOMEM;
 130                 goto err_free_res;
 131         }
 132
 133         error = request_irq(ps2if->irq, altera_ps2_rxint, 0, pdev->name, ps2if);
 134         if (error) {
 135                 dev_err(&pdev->dev, "could not allocate IRQ %d: %d\n",
 136                         ps2if->irq, error);
 137                 goto err_unmap;
 138         }
 139
 140         dev_info(&pdev->dev, "base %p, irq %d\n", ps2if->base, ps2if->irq);
 141
 142         serio_register_port(ps2if->io);
 143         platform_set_drvdata(pdev, ps2if);
 144
 145         return 0;
 146
 147  err_unmap:
 148         iounmap(ps2if->base);
 149  err_free_res:
 150         release_mem_region(ps2if->iomem_res->start,
 151                            resource_size(ps2if->iomem_res));
 152  err_free_mem:
 153         kfree(ps2if);
 154         kfree(serio);
 155         return error;
 156 }
 157
 158 /*
 159  * Remove one device from this driver.
 160  */
 161 static int altera_ps2_remove(struct platform_device *pdev)
 162 {
 163         struct ps2if *ps2if = platform_get_drvdata(pdev);
 164
 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 #ifdef CONFIG_OF
 176 static const struct of_device_id altera_ps2_match[] = {
 177         { .compatible = "ALTR,ps2-1.0", },
 178         { .compatible = "altr,ps2-1.0", },
 179         {},
 180 };
 181 MODULE_DEVICE_TABLE(of, altera_ps2_match);
 182 #endif /* CONFIG_OF */
 183
 184 /*
 185  * Our device driver structure
 186  */
 187 static struct platform_driver altera_ps2_driver = {
 188         .probe          = altera_ps2_probe,
 189         .remove         = altera_ps2_remove,
 190         .driver = {
 191                 .name   = DRV_NAME,
 192                 .owner  = THIS_MODULE,
 193                 .of_match_table = of_match_ptr(altera_ps2_match),
 194         },
 195 };
 196 module_platform_driver(altera_ps2_driver);
 197
 198 MODULE_DESCRIPTION("Altera University Program PS2 controller driver");
 199 MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
 200 MODULE_LICENSE("GPL");
 201 MODULE_ALIAS("platform:" DRV_NAME);