mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-06 10:06:39 +07:00
eb1f293060
The Synchronous Serial Controller (SSC) on Atmel microprocessors are capable of tranceiving many frame based protocols, like I2S. Tested on the AT32AP7000/ATSTK1000. This driver is used in the ALSA sound driver for the AT73C213 external DAC on the ATSTK1000 development board for AVR32. This sound driver will be submitted soon. Hardware documentation can be found in the AT32AP7000 data sheet, which can be downloaded from http://www.atmel.com/dyn/products/datasheets.asp?family_id=682 [akpm@linux-foundation.org: init spinlock at compile time] Signed-off-by: Hans-Christian Egtvedt <hcegtvedt@atmel.com> Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com> Cc: David Brownell <david-b@pacbell.net> Cc: Andrew Victor <andrew@sanpeople.com> Cc: Patrice Vilchez <patrice.vilchez@rfo.atmel.com> Cc: Nicolas Ferre <nicolas.ferre@rfo.atmel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
175 lines
3.5 KiB
C
175 lines
3.5 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/list.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/atmel-ssc.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);
|
|
dev_dbg(&ssc->pdev->dev, "could not find requested device\n");
|
|
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, regs->end - regs->start + 1);
|
|
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",
|
|
},
|
|
};
|
|
|
|
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");
|