LXR linux/drivers/input/serio/altera

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Altera University Program PS2 controller driver
   4 *
   5 * Copyright (C) 2008 Thomas Chou <thomas@wytron.com.tw>
   6 *
   7 * Based on sa1111ps2.c, which is:
   8 * Copyright (C) 2002 Russell King
   9 */
  10
  11#include <linux/module.h>
  12#include <linux/input.h>
  13#include <linux/serio.h>
  14#include <linux/interrupt.h>
  15#include <linux/platform_device.h>
  16#include <linux/io.h>
  17#include <linux/slab.h>
  18#include <linux/of.h>
  19
  20#define DRV_NAME "altera_ps2"
  21
  22struct ps2if {
  23        struct serio *io;
  24        void __iomem *base;
  25};
  26
  27/*
  28 * Read all bytes waiting in the PS2 port.  There should be
  29 * at the most one, but we loop for safety.
  30 */
  31static irqreturn_t altera_ps2_rxint(int irq, void *dev_id)
  32{
  33        struct ps2if *ps2if = dev_id;
  34        unsigned int status;
  35        irqreturn_t handled = IRQ_NONE;
  36
  37        while ((status = readl(ps2if->base)) & 0xffff0000) {
  38                serio_interrupt(ps2if->io, status & 0xff, 0);
  39                handled = IRQ_HANDLED;
  40        }
  41
  42        return handled;
  43}
  44
  45/*
  46 * Write a byte to the PS2 port.
  47 */
  48static int altera_ps2_write(struct serio *io, unsigned char val)
  49{
  50        struct ps2if *ps2if = io->port_data;
  51
  52        writel(val, ps2if->base);
  53        return 0;
  54}
  55
  56static int altera_ps2_open(struct serio *io)
  57{
  58        struct ps2if *ps2if = io->port_data;
  59
  60        /* clear fifo */
  61        while (readl(ps2if->base) & 0xffff0000)
  62                /* empty */;
  63
  64        writel(1, ps2if->base + 4); /* enable rx irq */
  65        return 0;
  66}
  67
  68static void altera_ps2_close(struct serio *io)
  69{
  70        struct ps2if *ps2if = io->port_data;
  71
  72        writel(0, ps2if->base + 4); /* disable rx irq */
  73}
  74
  75/*
  76 * Add one device to this driver.
  77 */
  78static int altera_ps2_probe(struct platform_device *pdev)
  79{
  80        struct ps2if *ps2if;
  81        struct resource *res;
  82        struct serio *serio;
  83        int error, irq;
  84
  85        ps2if = devm_kzalloc(&pdev->dev, sizeof(struct ps2if), GFP_KERNEL);
  86        if (!ps2if)
  87                return -ENOMEM;
  88
  89        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  90        ps2if->base = devm_ioremap_resource(&pdev->dev, res);
  91        if (IS_ERR(ps2if->base))
  92                return PTR_ERR(ps2if->base);
  93
  94        irq = platform_get_irq(pdev, 0);
  95        if (irq < 0)
  96                return -ENXIO;
  97
  98        error = devm_request_irq(&pdev->dev, irq, altera_ps2_rxint, 0,
  99                                 pdev->name, ps2if);
 100        if (error) {
 101                dev_err(&pdev->dev, "could not request IRQ %d\n", irq);
 102                return error;
 103        }
 104
 105        serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
 106        if (!serio)
 107                return -ENOMEM;
 108
 109        serio->id.type          = SERIO_8042;
 110        serio->write            = altera_ps2_write;
 111        serio->open             = altera_ps2_open;
 112        serio->close            = altera_ps2_close;
 113        strlcpy(serio->name, dev_name(&pdev->dev), sizeof(serio->name));
 114        strlcpy(serio->phys, dev_name(&pdev->dev), sizeof(serio->phys));
 115        serio->port_data        = ps2if;
 116        serio->dev.parent       = &pdev->dev;
 117        ps2if->io               = serio;
 118
 119        dev_info(&pdev->dev, "base %p, irq %d\n", ps2if->base, irq);
 120
 121        serio_register_port(ps2if->io);
 122        platform_set_drvdata(pdev, ps2if);
 123
 124        return 0;
 125}
 126
 127/*
 128 * Remove one device from this driver.
 129 */
 130static int altera_ps2_remove(struct platform_device *pdev)
 131{
 132        struct ps2if *ps2if = platform_get_drvdata(pdev);
 133
 134        serio_unregister_port(ps2if->io);
 135
 136        return 0;
 137}
 138
 139#ifdef CONFIG_OF
 140static const struct of_device_id altera_ps2_match[] = {
 141        { .compatible = "ALTR,ps2-1.0", },
 142        { .compatible = "altr,ps2-1.0", },
 143        {},
 144};
 145MODULE_DEVICE_TABLE(of, altera_ps2_match);
 146#endif /* CONFIG_OF */
 147
 148/*
 149 * Our device driver structure
 150 */
 151static struct platform_driver altera_ps2_driver = {
 152        .probe          = altera_ps2_probe,
 153        .remove         = altera_ps2_remove,
 154        .driver = {
 155                .name   = DRV_NAME,
 156                .of_match_table = of_match_ptr(altera_ps2_match),
 157        },
 158};
 159module_platform_driver(altera_ps2_driver);
 160
 161MODULE_DESCRIPTION("Altera University Program PS2 controller driver");
 162MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
 163MODULE_LICENSE("GPL");
 164MODULE_ALIAS("platform:" DRV_NAME);
 165