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 #include <linux/slab.h>
  22 #include <linux/of.h>
  23
  24 #define DRV_NAME "altera_ps2"
  25
  26 struct ps2if {
  27         struct serio *io;
  28         struct resource *iomem_res;
  29         void __iomem *base;
  30         unsigned irq;
  31 };
  32
  33 /*
  34  * Read all bytes waiting in the PS2 port.  There should be
  35  * at the most one, but we loop for safety.
  36  */
  37 static irqreturn_t altera_ps2_rxint(int irq, void *dev_id)
  38 {
  39         struct ps2if *ps2if = dev_id;
  40         unsigned int status;
  41         int handled = IRQ_NONE;
  42
  43         while ((status = readl(ps2if->base)) & 0xffff0000) {
  44                 serio_interrupt(ps2if->io, status & 0xff, 0);
  45                 handled = IRQ_HANDLED;
  46         }
  47
  48         return handled;
  49 }
  50
  51 /*
  52  * Write a byte to the PS2 port.
  53  */
  54 static int altera_ps2_write(struct serio *io, unsigned char val)
  55 {
  56         struct ps2if *ps2if = io->port_data;
  57
  58         writel(val, ps2if->base);
  59         return 0;
  60 }
  61
  62 static int altera_ps2_open(struct serio *io)
  63 {
  64         struct ps2if *ps2if = io->port_data;
  65
  66         /* clear fifo */
  67         while (readl(ps2if->base) & 0xffff0000)
  68                 /* empty */;
  69
  70         writel(1, ps2if->base + 4); /* enable rx irq */
  71         return 0;
  72 }
  73
  74 static void altera_ps2_close(struct serio *io)
  75 {
  76         struct ps2if *ps2if = io->port_data;
  77
  78         writel(0, ps2if->base); /* disable rx irq */
  79 }
  80
  81 /*
  82  * Add one device to this driver.
  83  */
  84 static int altera_ps2_probe(struct platform_device *pdev)
  85 {
  86         struct ps2if *ps2if;
  87         struct serio *serio;
  88         int error, irq;
  89
  90         ps2if = kzalloc(sizeof(struct ps2if), GFP_KERNEL);
  91         serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
  92         if (!ps2if || !serio) {
  93                 error = -ENOMEM;
  94                 goto err_free_mem;
  95         }
  96
  97         serio->id.type          = SERIO_8042;
  98         serio->write            = altera_ps2_write;
  99         serio->open             = altera_ps2_open;
 100         serio->close            = altera_ps2_close;
 101         strlcpy(serio->name, dev_name(&pdev->dev), sizeof(serio->name));
 102         strlcpy(serio->phys, dev_name(&pdev->dev), sizeof(serio->phys));
 103         serio->port_data        = ps2if;
 104         serio->dev.parent       = &pdev->dev;
 105         ps2if->io               = serio;
 106
 107         ps2if->iomem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 108         if (ps2if->iomem_res == NULL) {
 109                 error = -ENOENT;
 110                 goto err_free_mem;
 111         }
 112
 113
 114         irq = platform_get_irq(pdev, 0);
 115         if (irq < 0) {
 116                 error = -ENXIO;
 117                 goto err_free_mem;
 118         }
 119         ps2if->irq = irq;
 120
 121         if (!request_mem_region(ps2if->iomem_res->start,
 122                                 resource_size(ps2if->iomem_res), pdev->name)) {
 123                 error = -EBUSY;
 124                 goto err_free_mem;
 125         }
 126
 127         ps2if->base = ioremap(ps2if->iomem_res->start,
 128                               resource_size(ps2if->iomem_res));
 129         if (!ps2if->base) {
 130                 error = -ENOMEM;
 131                 goto err_free_res;
 132         }
 133
 134         error = request_irq(ps2if->irq, altera_ps2_rxint, 0, pdev->name, ps2if);
 135         if (error) {
 136                 dev_err(&pdev->dev, "could not allocate IRQ %d: %d\n",
 137                         ps2if->irq, error);
 138                 goto err_unmap;
 139         }
 140
 141         dev_info(&pdev->dev, "base %p, irq %d\n", ps2if->base, ps2if->irq);
 142
 143         serio_register_port(ps2if->io);
 144         platform_set_drvdata(pdev, ps2if);
 145
 146         return 0;
 147
 148  err_unmap:
 149         iounmap(ps2if->base);
 150  err_free_res:
 151         release_mem_region(ps2if->iomem_res->start,
 152                            resource_size(ps2if->iomem_res));
 153  err_free_mem:
 154         kfree(ps2if);
 155         kfree(serio);
 156         return error;
 157 }
 158
 159 /*
 160  * Remove one device from this driver.
 161  */
 162 static int altera_ps2_remove(struct platform_device *pdev)
 163 {
 164         struct ps2if *ps2if = platform_get_drvdata(pdev);
 165
 166         platform_set_drvdata(pdev, NULL);
 167         serio_unregister_port(ps2if->io);
 168         free_irq(ps2if->irq, ps2if);
 169         iounmap(ps2if->base);
 170         release_mem_region(ps2if->iomem_res->start,
 171                            resource_size(ps2if->iomem_res));
 172         kfree(ps2if);
 173
 174         return 0;
 175 }
 176
 177 #ifdef CONFIG_OF
 178 static const struct of_device_id altera_ps2_match[] = {
 179         { .compatible = "ALTR,ps2-1.0", },
 180         {},
 181 };
 182 MODULE_DEVICE_TABLE(of, altera_ps2_match);
 183 #endif /* CONFIG_OF */
 184
 185 /*
 186  * Our device driver structure
 187  */
 188 static struct platform_driver altera_ps2_driver = {
 189         .probe          = altera_ps2_probe,
 190         .remove         = altera_ps2_remove,
 191         .driver = {
 192                 .name   = DRV_NAME,
 193                 .owner  = THIS_MODULE,
 194                 .of_match_table = of_match_ptr(altera_ps2_match),
 195         },
 196 };
 197 module_platform_driver(altera_ps2_driver);
 198
 199 MODULE_DESCRIPTION("Altera University Program PS2 controller driver");
 200 MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
 201 MODULE_LICENSE("GPL");
 202 MODULE_ALIAS("platform:" DRV_NAME);