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linux/drivers/mfd/mcp-sa11x0.c
Uwe Kleine-König a861a27a0e mfd: mcp-sa11x0: Convert to platform remove callback returning void 
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.

To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new(), which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20231123165627.492259-9-u.kleine-koenig@pengutronix.de
Signed-off-by: Lee Jones <lee@kernel.org>
2023-12-07 13:50:27 +00:00

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// SPDX-License-Identifier: GPL-2.0-only
/*
* linux/drivers/mfd/mcp-sa11x0.c
*
* Copyright (C) 2001-2005 Russell King
*
* SA11x0 MCP (Multimedia Communications Port) driver.
*
* MCP read/write timeouts from Jordi Colomer, rehacked by rmk.
*/
#include <linux/module.h>
#include <linux/io.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/spinlock.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/mfd/mcp.h>
#include <mach/hardware.h>
#include <asm/mach-types.h>
#include <linux/platform_data/mfd-mcp-sa11x0.h>
#define DRIVER_NAME "sa11x0-mcp"
struct mcp_sa11x0 {
void __iomem *base0;
void __iomem *base1;
u32 mccr0;
u32 mccr1;
};
/* Register offsets */
#define MCCR0(m) ((m)->base0 + 0x00)
#define MCDR0(m) ((m)->base0 + 0x08)
#define MCDR1(m) ((m)->base0 + 0x0c)
#define MCDR2(m) ((m)->base0 + 0x10)
#define MCSR(m) ((m)->base0 + 0x18)
#define MCCR1(m) ((m)->base1 + 0x00)
#define priv(mcp) ((struct mcp_sa11x0 *)mcp_priv(mcp))
static void
mcp_sa11x0_set_telecom_divisor(struct mcp *mcp, unsigned int divisor)
{
struct mcp_sa11x0 *m = priv(mcp);
divisor /= 32;
m->mccr0 &= ~0x00007f00;
m->mccr0 |= divisor << 8;
writel_relaxed(m->mccr0, MCCR0(m));
}
static void
mcp_sa11x0_set_audio_divisor(struct mcp *mcp, unsigned int divisor)
{
struct mcp_sa11x0 *m = priv(mcp);
divisor /= 32;
m->mccr0 &= ~0x0000007f;
m->mccr0 |= divisor;
writel_relaxed(m->mccr0, MCCR0(m));
}
/*
* Write data to the device. The bit should be set after 3 subframe
* times (each frame is 64 clocks). We wait a maximum of 6 subframes.
* We really should try doing something more productive while we
* wait.
*/
static void
mcp_sa11x0_write(struct mcp *mcp, unsigned int reg, unsigned int val)
{
struct mcp_sa11x0 *m = priv(mcp);
int ret = -ETIME;
int i;
writel_relaxed(reg << 17 | MCDR2_Wr | (val & 0xffff), MCDR2(m));
for (i = 0; i < 2; i++) {
udelay(mcp->rw_timeout);
if (readl_relaxed(MCSR(m)) & MCSR_CWC) {
ret = 0;
break;
}
}
if (ret < 0)
printk(KERN_WARNING "mcp: write timed out\n");
}
/*
* Read data from the device. The bit should be set after 3 subframe
* times (each frame is 64 clocks). We wait a maximum of 6 subframes.
* We really should try doing something more productive while we
* wait.
*/
static unsigned int
mcp_sa11x0_read(struct mcp *mcp, unsigned int reg)
{
struct mcp_sa11x0 *m = priv(mcp);
int ret = -ETIME;
int i;
writel_relaxed(reg << 17 | MCDR2_Rd, MCDR2(m));
for (i = 0; i < 2; i++) {
udelay(mcp->rw_timeout);
if (readl_relaxed(MCSR(m)) & MCSR_CRC) {
ret = readl_relaxed(MCDR2(m)) & 0xffff;
break;
}
}
if (ret < 0)
printk(KERN_WARNING "mcp: read timed out\n");
return ret;
}
static void mcp_sa11x0_enable(struct mcp *mcp)
{
struct mcp_sa11x0 *m = priv(mcp);
writel(-1, MCSR(m));
m->mccr0 |= MCCR0_MCE;
writel_relaxed(m->mccr0, MCCR0(m));
}
static void mcp_sa11x0_disable(struct mcp *mcp)
{
struct mcp_sa11x0 *m = priv(mcp);
m->mccr0 &= ~MCCR0_MCE;
writel_relaxed(m->mccr0, MCCR0(m));
}
/*
* Our methods.
*/
static struct mcp_ops mcp_sa11x0 = {
.set_telecom_divisor = mcp_sa11x0_set_telecom_divisor,
.set_audio_divisor = mcp_sa11x0_set_audio_divisor,
.reg_write = mcp_sa11x0_write,
.reg_read = mcp_sa11x0_read,
.enable = mcp_sa11x0_enable,
.disable = mcp_sa11x0_disable,
};
static int mcp_sa11x0_probe(struct platform_device *dev)
{
struct mcp_plat_data *data = dev_get_platdata(&dev->dev);
struct resource *mem0, *mem1;
struct mcp_sa11x0 *m;
struct mcp *mcp;
int ret;
if (!data)
return -ENODEV;
mem0 = platform_get_resource(dev, IORESOURCE_MEM, 0);
mem1 = platform_get_resource(dev, IORESOURCE_MEM, 1);
if (!mem0 || !mem1)
return -ENXIO;
if (!request_mem_region(mem0->start, resource_size(mem0),
DRIVER_NAME)) {
ret = -EBUSY;
goto err_mem0;
}
if (!request_mem_region(mem1->start, resource_size(mem1),
DRIVER_NAME)) {
ret = -EBUSY;
goto err_mem1;
}
mcp = mcp_host_alloc(&dev->dev, sizeof(struct mcp_sa11x0));
if (!mcp) {
ret = -ENOMEM;
goto err_alloc;
}
mcp->owner = THIS_MODULE;
mcp->ops = &mcp_sa11x0;
mcp->sclk_rate = data->sclk_rate;
m = priv(mcp);
m->mccr0 = data->mccr0 | 0x7f7f;
m->mccr1 = data->mccr1;
m->base0 = ioremap(mem0->start, resource_size(mem0));
m->base1 = ioremap(mem1->start, resource_size(mem1));
if (!m->base0 || !m->base1) {
ret = -ENOMEM;
goto err_ioremap;
}
platform_set_drvdata(dev, mcp);
/*
* Initialise device. Note that we initially
* set the sampling rate to minimum.
*/
writel_relaxed(-1, MCSR(m));
writel_relaxed(m->mccr1, MCCR1(m));
writel_relaxed(m->mccr0, MCCR0(m));
/*
* Calculate the read/write timeout (us) from the bit clock
* rate. This is the period for 3 64-bit frames. Always
* round this time up.
*/
mcp->rw_timeout = DIV_ROUND_UP(64 * 3 * 1000000, mcp->sclk_rate);
ret = mcp_host_add(mcp, data->codec_pdata);
if (ret == 0)
return 0;
err_ioremap:
iounmap(m->base1);
iounmap(m->base0);
mcp_host_free(mcp);
err_alloc:
release_mem_region(mem1->start, resource_size(mem1));
err_mem1:
release_mem_region(mem0->start, resource_size(mem0));
err_mem0:
return ret;
}
static void mcp_sa11x0_remove(struct platform_device *dev)
{
struct mcp *mcp = platform_get_drvdata(dev);
struct mcp_sa11x0 *m = priv(mcp);
struct resource *mem0, *mem1;
if (m->mccr0 & MCCR0_MCE)
dev_warn(&dev->dev,
"device left active (missing disable call?)\n");
mem0 = platform_get_resource(dev, IORESOURCE_MEM, 0);
mem1 = platform_get_resource(dev, IORESOURCE_MEM, 1);
mcp_host_del(mcp);
iounmap(m->base1);
iounmap(m->base0);
mcp_host_free(mcp);
release_mem_region(mem1->start, resource_size(mem1));
release_mem_region(mem0->start, resource_size(mem0));
}
static int mcp_sa11x0_suspend(struct device *dev)
{
struct mcp_sa11x0 *m = priv(dev_get_drvdata(dev));
if (m->mccr0 & MCCR0_MCE)
dev_warn(dev, "device left active (missing disable call?)\n");
writel(m->mccr0 & ~MCCR0_MCE, MCCR0(m));
return 0;
}
static int mcp_sa11x0_resume(struct device *dev)
{
struct mcp_sa11x0 *m = priv(dev_get_drvdata(dev));
writel_relaxed(m->mccr1, MCCR1(m));
writel_relaxed(m->mccr0, MCCR0(m));
return 0;
}
static const struct dev_pm_ops mcp_sa11x0_pm_ops = {
.suspend = mcp_sa11x0_suspend,
.freeze = mcp_sa11x0_suspend,
.poweroff = mcp_sa11x0_suspend,
.resume_noirq = mcp_sa11x0_resume,
.thaw_noirq = mcp_sa11x0_resume,
.restore_noirq = mcp_sa11x0_resume,
};
static struct platform_driver mcp_sa11x0_driver = {
.probe = mcp_sa11x0_probe,
.remove_new = mcp_sa11x0_remove,
.driver = {
.name = DRIVER_NAME,
.pm = pm_sleep_ptr(&mcp_sa11x0_pm_ops),
},
};
/*
* This needs re-working
*/
module_platform_driver(mcp_sa11x0_driver);
MODULE_ALIAS("platform:" DRIVER_NAME);
MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
MODULE_DESCRIPTION("SA11x0 multimedia communications port driver");
MODULE_LICENSE("GPL");
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