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
 26struct 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 */
 37static 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 */
 54static 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
 62static 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
 74static 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 */
 84static int __devinit 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 */
162static int __devexit 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
178static const struct of_device_id altera_ps2_match[] = {
179	{ .compatible = "ALTR,ps2-1.0", },
180	{},
181};
182MODULE_DEVICE_TABLE(of, altera_ps2_match);
183#endif /* CONFIG_OF */
184
185/*
186 * Our device driver structure
187 */
188static struct platform_driver altera_ps2_driver = {
189	.probe		= altera_ps2_probe,
190	.remove		= __devexit_p(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};
197module_platform_driver(altera_ps2_driver);
198
199MODULE_DESCRIPTION("Altera University Program PS2 controller driver");
200MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
201MODULE_LICENSE("GPL");
202MODULE_ALIAS("platform:" DRV_NAME);