linux/drivers/misc/atmel-ssc.c
Paul Gortmaker eb12a679b2 drivers/misc: Add module.h to files who are really modular.
These files really need the full module.h header file present, but
were just getting it implicitly before.  Fix it up in advance so we
avoid build failures once the cleanup commit is present.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 19:31:53 -04:00

178 lines
3.6 KiB
C

/*
* Atmel SSC driver
*
* Copyright (C) 2007 Atmel Corporation
*
* 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/platform_device.h>
#include <linux/list.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/spinlock.h>
#include <linux/atmel-ssc.h>
#include <linux/slab.h>
#include <linux/module.h>
/* Serialize access to ssc_list and user count */
static DEFINE_SPINLOCK(user_lock);
static LIST_HEAD(ssc_list);
struct ssc_device *ssc_request(unsigned int ssc_num)
{
int ssc_valid = 0;
struct ssc_device *ssc;
spin_lock(&user_lock);
list_for_each_entry(ssc, &ssc_list, list) {
if (ssc->pdev->id == ssc_num) {
ssc_valid = 1;
break;
}
}
if (!ssc_valid) {
spin_unlock(&user_lock);
pr_err("ssc: ssc%d platform device is missing\n", ssc_num);
return ERR_PTR(-ENODEV);
}
if (ssc->user) {
spin_unlock(&user_lock);
dev_dbg(&ssc->pdev->dev, "module busy\n");
return ERR_PTR(-EBUSY);
}
ssc->user++;
spin_unlock(&user_lock);
clk_enable(ssc->clk);
return ssc;
}
EXPORT_SYMBOL(ssc_request);
void ssc_free(struct ssc_device *ssc)
{
spin_lock(&user_lock);
if (ssc->user) {
ssc->user--;
clk_disable(ssc->clk);
} else {
dev_dbg(&ssc->pdev->dev, "device already free\n");
}
spin_unlock(&user_lock);
}
EXPORT_SYMBOL(ssc_free);
static int __init ssc_probe(struct platform_device *pdev)
{
int retval = 0;
struct resource *regs;
struct ssc_device *ssc;
ssc = kzalloc(sizeof(struct ssc_device), GFP_KERNEL);
if (!ssc) {
dev_dbg(&pdev->dev, "out of memory\n");
retval = -ENOMEM;
goto out;
}
regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!regs) {
dev_dbg(&pdev->dev, "no mmio resource defined\n");
retval = -ENXIO;
goto out_free;
}
ssc->clk = clk_get(&pdev->dev, "pclk");
if (IS_ERR(ssc->clk)) {
dev_dbg(&pdev->dev, "no pclk clock defined\n");
retval = -ENXIO;
goto out_free;
}
ssc->pdev = pdev;
ssc->regs = ioremap(regs->start, resource_size(regs));
if (!ssc->regs) {
dev_dbg(&pdev->dev, "ioremap failed\n");
retval = -EINVAL;
goto out_clk;
}
/* disable all interrupts */
clk_enable(ssc->clk);
ssc_writel(ssc->regs, IDR, ~0UL);
ssc_readl(ssc->regs, SR);
clk_disable(ssc->clk);
ssc->irq = platform_get_irq(pdev, 0);
if (!ssc->irq) {
dev_dbg(&pdev->dev, "could not get irq\n");
retval = -ENXIO;
goto out_unmap;
}
spin_lock(&user_lock);
list_add_tail(&ssc->list, &ssc_list);
spin_unlock(&user_lock);
platform_set_drvdata(pdev, ssc);
dev_info(&pdev->dev, "Atmel SSC device at 0x%p (irq %d)\n",
ssc->regs, ssc->irq);
goto out;
out_unmap:
iounmap(ssc->regs);
out_clk:
clk_put(ssc->clk);
out_free:
kfree(ssc);
out:
return retval;
}
static int __devexit ssc_remove(struct platform_device *pdev)
{
struct ssc_device *ssc = platform_get_drvdata(pdev);
spin_lock(&user_lock);
iounmap(ssc->regs);
clk_put(ssc->clk);
list_del(&ssc->list);
kfree(ssc);
spin_unlock(&user_lock);
return 0;
}
static struct platform_driver ssc_driver = {
.remove = __devexit_p(ssc_remove),
.driver = {
.name = "ssc",
.owner = THIS_MODULE,
},
};
static int __init ssc_init(void)
{
return platform_driver_probe(&ssc_driver, ssc_probe);
}
module_init(ssc_init);
static void __exit ssc_exit(void)
{
platform_driver_unregister(&ssc_driver);
}
module_exit(ssc_exit);
MODULE_AUTHOR("Hans-Christian Egtvedt <hcegtvedt@atmel.com>");
MODULE_DESCRIPTION("SSC driver for Atmel AVR32 and AT91");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:ssc");