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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* linux/drivers/input/serio/ambakmi.c
*
* Copyright (C) 2000-2003 Deep Blue Solutions Ltd.
* Copyright (C) 2002 Russell King.
*/
#include <linux/module.h>
#include <linux/serio.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/device.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/amba/bus.h>
#include <linux/amba/kmi.h>
#include <linux/clk.h>
#include <asm/io.h>
#include <asm/irq.h>
#define KMI_BASE (kmi->base)
struct amba_kmi_port {
struct serio *io;
struct clk *clk;
void __iomem *base;
unsigned int irq;
unsigned int divisor;
unsigned int open;
};
static irqreturn_t amba_kmi_int(int irq, void *dev_id)
{
struct amba_kmi_port *kmi = dev_id;
unsigned int status = readb(KMIIR);
int handled = IRQ_NONE;
while (status & KMIIR_RXINTR) {
serio_interrupt(kmi->io, readb(KMIDATA), 0);
status = readb(KMIIR);
handled = IRQ_HANDLED;
}
return handled;
}
static int amba_kmi_write(struct serio *io, unsigned char val)
{
struct amba_kmi_port *kmi = io->port_data;
unsigned int timeleft = 10000; /* timeout in 100ms */
while ((readb(KMISTAT) & KMISTAT_TXEMPTY) == 0 && --timeleft)
udelay(10);
if (timeleft)
writeb(val, KMIDATA);
return timeleft ? 0 : SERIO_TIMEOUT;
}
static int amba_kmi_open(struct serio *io)
{
struct amba_kmi_port *kmi = io->port_data;
unsigned int divisor;
int ret;
ret = clk_prepare_enable(kmi->clk);
if (ret)
goto out;
divisor = clk_get_rate(kmi->clk) / 8000000 - 1;
writeb(divisor, KMICLKDIV);
writeb(KMICR_EN, KMICR);
ret = request_irq(kmi->irq, amba_kmi_int, IRQF_SHARED, "kmi-pl050",
kmi);
if (ret) {
printk(KERN_ERR "kmi: failed to claim IRQ%d\n", kmi->irq);
writeb(0, KMICR);
goto clk_disable;
}
writeb(KMICR_EN | KMICR_RXINTREN, KMICR);
return 0;
clk_disable:
clk_disable_unprepare(kmi->clk);
out:
return ret;
}
static void amba_kmi_close(struct serio *io)
{
struct amba_kmi_port *kmi = io->port_data;
writeb(0, KMICR);
free_irq(kmi->irq, kmi);
clk_disable_unprepare(kmi->clk);
}
static int amba_kmi_probe(struct amba_device *dev,
const struct amba_id *id)
{
struct amba_kmi_port *kmi;
struct serio *io;
int ret;
ret = amba_request_regions(dev, NULL);
if (ret)
return ret;
kmi = kzalloc(sizeof(struct amba_kmi_port), GFP_KERNEL);
io = kzalloc(sizeof(struct serio), GFP_KERNEL);
if (!kmi || !io) {
ret = -ENOMEM;
goto out;
}
io->id.type = SERIO_8042;
io->write = amba_kmi_write;
io->open = amba_kmi_open;
io->close = amba_kmi_close;
strscpy(io->name, dev_name(&dev->dev), sizeof(io->name));
strscpy(io->phys, dev_name(&dev->dev), sizeof(io->phys));
io->port_data = kmi;
io->dev.parent = &dev->dev;
kmi->io = io;
kmi->base = ioremap(dev->res.start, resource_size(&dev->res));
if (!kmi->base) {
ret = -ENOMEM;
goto out;
}
kmi->clk = clk_get(&dev->dev, "KMIREFCLK");
if (IS_ERR(kmi->clk)) {
ret = PTR_ERR(kmi->clk);
goto unmap;
}
kmi->irq = dev->irq[0];
amba_set_drvdata(dev, kmi);
serio_register_port(kmi->io);
return 0;
unmap:
iounmap(kmi->base);
out:
kfree(kmi);
kfree(io);
amba_release_regions(dev);
return ret;
}
static void amba_kmi_remove(struct amba_device *dev)
{
struct amba_kmi_port *kmi = amba_get_drvdata(dev);
serio_unregister_port(kmi->io);
clk_put(kmi->clk);
iounmap(kmi->base);
kfree(kmi);
amba_release_regions(dev);
}
static int __maybe_unused amba_kmi_resume(struct device *dev)
{
struct amba_kmi_port *kmi = dev_get_drvdata(dev);
/* kick the serio layer to rescan this port */
serio_reconnect(kmi->io);
return 0;
}
static SIMPLE_DEV_PM_OPS(amba_kmi_dev_pm_ops, NULL, amba_kmi_resume);
static const struct amba_id amba_kmi_idtable[] = {
{
.id = 0x00041050,
.mask = 0x000fffff,
},
{ 0, 0 }
};
MODULE_DEVICE_TABLE(amba, amba_kmi_idtable);
static struct amba_driver ambakmi_driver = {
.drv = {
.name = "kmi-pl050",
.owner = THIS_MODULE,
.pm = &amba_kmi_dev_pm_ops,
},
.id_table = amba_kmi_idtable,
.probe = amba_kmi_probe,
.remove = amba_kmi_remove,
};
module_amba_driver(ambakmi_driver);
MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
MODULE_DESCRIPTION("AMBA KMI controller driver");
MODULE_LICENSE("GPL");
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