165 lines
3.6 KiB
C
165 lines
3.6 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Altera University Program PS2 controller driver
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*
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* Copyright (C) 2008 Thomas Chou <thomas@wytron.com.tw>
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*
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* Based on sa1111ps2.c, which is:
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* Copyright (C) 2002 Russell King
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*/
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#include <linux/module.h>
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#include <linux/input.h>
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#include <linux/serio.h>
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#include <linux/interrupt.h>
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#include <linux/platform_device.h>
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#include <linux/io.h>
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#include <linux/slab.h>
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#include <linux/of.h>
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#define DRV_NAME "altera_ps2"
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struct ps2if {
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struct serio *io;
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void __iomem *base;
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};
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/*
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* Read all bytes waiting in the PS2 port. There should be
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* at the most one, but we loop for safety.
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*/
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static irqreturn_t altera_ps2_rxint(int irq, void *dev_id)
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{
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struct ps2if *ps2if = dev_id;
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unsigned int status;
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irqreturn_t handled = IRQ_NONE;
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while ((status = readl(ps2if->base)) & 0xffff0000) {
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serio_interrupt(ps2if->io, status & 0xff, 0);
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handled = IRQ_HANDLED;
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}
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return handled;
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}
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/*
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* Write a byte to the PS2 port.
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*/
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static int altera_ps2_write(struct serio *io, unsigned char val)
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{
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struct ps2if *ps2if = io->port_data;
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writel(val, ps2if->base);
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return 0;
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}
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static int altera_ps2_open(struct serio *io)
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{
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struct ps2if *ps2if = io->port_data;
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/* clear fifo */
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while (readl(ps2if->base) & 0xffff0000)
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/* empty */;
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writel(1, ps2if->base + 4); /* enable rx irq */
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return 0;
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}
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static void altera_ps2_close(struct serio *io)
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{
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struct ps2if *ps2if = io->port_data;
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writel(0, ps2if->base + 4); /* disable rx irq */
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}
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/*
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* Add one device to this driver.
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*/
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static int altera_ps2_probe(struct platform_device *pdev)
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{
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struct ps2if *ps2if;
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struct resource *res;
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struct serio *serio;
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int error, irq;
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ps2if = devm_kzalloc(&pdev->dev, sizeof(struct ps2if), GFP_KERNEL);
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if (!ps2if)
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return -ENOMEM;
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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ps2if->base = devm_ioremap_resource(&pdev->dev, res);
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if (IS_ERR(ps2if->base))
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return PTR_ERR(ps2if->base);
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irq = platform_get_irq(pdev, 0);
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if (irq < 0)
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return -ENXIO;
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error = devm_request_irq(&pdev->dev, irq, altera_ps2_rxint, 0,
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pdev->name, ps2if);
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if (error) {
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dev_err(&pdev->dev, "could not request IRQ %d\n", irq);
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return error;
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}
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serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
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if (!serio)
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return -ENOMEM;
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serio->id.type = SERIO_8042;
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serio->write = altera_ps2_write;
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serio->open = altera_ps2_open;
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serio->close = altera_ps2_close;
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strlcpy(serio->name, dev_name(&pdev->dev), sizeof(serio->name));
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strlcpy(serio->phys, dev_name(&pdev->dev), sizeof(serio->phys));
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serio->port_data = ps2if;
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serio->dev.parent = &pdev->dev;
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ps2if->io = serio;
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dev_info(&pdev->dev, "base %p, irq %d\n", ps2if->base, irq);
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serio_register_port(ps2if->io);
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platform_set_drvdata(pdev, ps2if);
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return 0;
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}
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/*
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* Remove one device from this driver.
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*/
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static int altera_ps2_remove(struct platform_device *pdev)
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{
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struct ps2if *ps2if = platform_get_drvdata(pdev);
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serio_unregister_port(ps2if->io);
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return 0;
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}
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#ifdef CONFIG_OF
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static const struct of_device_id altera_ps2_match[] = {
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{ .compatible = "ALTR,ps2-1.0", },
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{ .compatible = "altr,ps2-1.0", },
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{},
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};
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MODULE_DEVICE_TABLE(of, altera_ps2_match);
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#endif /* CONFIG_OF */
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/*
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* Our device driver structure
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*/
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static struct platform_driver altera_ps2_driver = {
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.probe = altera_ps2_probe,
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.remove = altera_ps2_remove,
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.driver = {
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.name = DRV_NAME,
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.of_match_table = of_match_ptr(altera_ps2_match),
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},
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};
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module_platform_driver(altera_ps2_driver);
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MODULE_DESCRIPTION("Altera University Program PS2 controller driver");
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MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:" DRV_NAME);
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