pxa930_trkball.c
/*
* PXA930 track ball mouse driver
*
* Copyright (C) 2007 Marvell International Ltd.
* 2008-02-28: Yong Yao <yaoyong@marvell.com>
* initial version
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/init.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <mach/hardware.h>
#include <linux/platform_data/mouse-pxa930_trkball.h>
/* Trackball Controller Register Definitions */
#define TBCR (0x000C)
#define TBCNTR (0x0010)
#define TBSBC (0x0014)
#define TBCR_TBRST (1 << 1)
#define TBCR_TBSB (1 << 10)
#define TBCR_Y_FLT(n) (((n) & 0xf) << 6)
#define TBCR_X_FLT(n) (((n) & 0xf) << 2)
#define TBCNTR_YM(n) (((n) >> 24) & 0xff)
#define TBCNTR_YP(n) (((n) >> 16) & 0xff)
#define TBCNTR_XM(n) (((n) >> 8) & 0xff)
#define TBCNTR_XP(n) ((n) & 0xff)
#define TBSBC_TBSBC (0x1)
struct pxa930_trkball {
struct pxa930_trkball_platform_data *pdata;
/* Memory Mapped Register */
struct resource *mem;
void __iomem *mmio_base;
struct input_dev *input;
};
static irqreturn_t pxa930_trkball_interrupt(int irq, void *dev_id)
{
struct pxa930_trkball *trkball = dev_id;
struct input_dev *input = trkball->input;
int tbcntr, x, y;
/* According to the spec software must read TBCNTR twice:
* if the read value is the same, the reading is valid
*/
tbcntr = __raw_readl(trkball->mmio_base + TBCNTR);
if (tbcntr == __raw_readl(trkball->mmio_base + TBCNTR)) {
x = (TBCNTR_XP(tbcntr) - TBCNTR_XM(tbcntr)) / 2;
y = (TBCNTR_YP(tbcntr) - TBCNTR_YM(tbcntr)) / 2;
input_report_rel(input, REL_X, x);
input_report_rel(input, REL_Y, y);
input_sync(input);
}
__raw_writel(TBSBC_TBSBC, trkball->mmio_base + TBSBC);
__raw_writel(0, trkball->mmio_base + TBSBC);
return IRQ_HANDLED;
}
/* For TBCR, we need to wait for a while to make sure it has been modified. */
static int write_tbcr(struct pxa930_trkball *trkball, int v)
{
int i = 100;
__raw_writel(v, trkball->mmio_base + TBCR);
while (--i) {
if (__raw_readl(trkball->mmio_base + TBCR) == v)
break;
msleep(1);
}
if (i == 0) {
pr_err("%s: timed out writing TBCR(%x)!\n", __func__, v);
return -ETIMEDOUT;
}
return 0;
}
static void pxa930_trkball_config(struct pxa930_trkball *trkball)
{
uint32_t tbcr;
/* According to spec, need to write the filters of x,y to 0xf first! */
tbcr = __raw_readl(trkball->mmio_base + TBCR);
write_tbcr(trkball, tbcr | TBCR_X_FLT(0xf) | TBCR_Y_FLT(0xf));
write_tbcr(trkball, TBCR_X_FLT(trkball->pdata->x_filter) |
TBCR_Y_FLT(trkball->pdata->y_filter));
/* According to spec, set TBCR_TBRST first, before clearing it! */
tbcr = __raw_readl(trkball->mmio_base + TBCR);
write_tbcr(trkball, tbcr | TBCR_TBRST);
write_tbcr(trkball, tbcr & ~TBCR_TBRST);
__raw_writel(TBSBC_TBSBC, trkball->mmio_base + TBSBC);
__raw_writel(0, trkball->mmio_base + TBSBC);
pr_debug("%s: final TBCR=%x!\n", __func__,
__raw_readl(trkball->mmio_base + TBCR));
}
static int pxa930_trkball_open(struct input_dev *dev)
{
struct pxa930_trkball *trkball = input_get_drvdata(dev);
pxa930_trkball_config(trkball);
return 0;
}
static void pxa930_trkball_disable(struct pxa930_trkball *trkball)
{
uint32_t tbcr = __raw_readl(trkball->mmio_base + TBCR);
/* Held in reset, gate the 32-KHz input clock off */
write_tbcr(trkball, tbcr | TBCR_TBRST);
}
static void pxa930_trkball_close(struct input_dev *dev)
{
struct pxa930_trkball *trkball = input_get_drvdata(dev);
pxa930_trkball_disable(trkball);
}
static int pxa930_trkball_probe(struct platform_device *pdev)
{
struct pxa930_trkball *trkball;
struct input_dev *input;
struct resource *res;
int irq, error;
irq = platform_get_irq(pdev, 0);
if (irq < 0) {
dev_err(&pdev->dev, "failed to get trkball irq\n");
return -ENXIO;
}
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
dev_err(&pdev->dev, "failed to get register memory\n");
return -ENXIO;
}
trkball = kzalloc(sizeof(struct pxa930_trkball), GFP_KERNEL);
if (!trkball)
return -ENOMEM;
trkball->pdata = pdev->dev.platform_data;
if (!trkball->pdata) {
dev_err(&pdev->dev, "no platform data defined\n");
error = -EINVAL;
goto failed;
}
trkball->mmio_base = ioremap_nocache(res->start, resource_size(res));
if (!trkball->mmio_base) {
dev_err(&pdev->dev, "failed to ioremap registers\n");
error = -ENXIO;
goto failed;
}
/* held the module in reset, will be enabled in open() */
pxa930_trkball_disable(trkball);
error = request_irq(irq, pxa930_trkball_interrupt, 0,
pdev->name, trkball);
if (error) {
dev_err(&pdev->dev, "failed to request irq: %d\n", error);
goto failed_free_io;
}
platform_set_drvdata(pdev, trkball);
input = input_allocate_device();
if (!input) {
dev_err(&pdev->dev, "failed to allocate input device\n");
error = -ENOMEM;
goto failed_free_irq;
}
input->name = pdev->name;
input->id.bustype = BUS_HOST;
input->open = pxa930_trkball_open;
input->close = pxa930_trkball_close;
input->dev.parent = &pdev->dev;
input_set_drvdata(input, trkball);
trkball->input = input;
input_set_capability(input, EV_REL, REL_X);
input_set_capability(input, EV_REL, REL_Y);
error = input_register_device(input);
if (error) {
dev_err(&pdev->dev, "unable to register input device\n");
goto failed_free_input;
}
return 0;
failed_free_input:
input_free_device(input);
failed_free_irq:
free_irq(irq, trkball);
failed_free_io:
iounmap(trkball->mmio_base);
failed:
kfree(trkball);
return error;
}
static int pxa930_trkball_remove(struct platform_device *pdev)
{
struct pxa930_trkball *trkball = platform_get_drvdata(pdev);
int irq = platform_get_irq(pdev, 0);
input_unregister_device(trkball->input);
free_irq(irq, trkball);
iounmap(trkball->mmio_base);
kfree(trkball);
return 0;
}
static struct platform_driver pxa930_trkball_driver = {
.driver = {
.name = "pxa930-trkball",
},
.probe = pxa930_trkball_probe,
.remove = pxa930_trkball_remove,
};
module_platform_driver(pxa930_trkball_driver);
MODULE_AUTHOR("Yong Yao <yaoyong@marvell.com>");
MODULE_DESCRIPTION("PXA930 Trackball Mouse Driver");
MODULE_LICENSE("GPL");