linux/drivers/mfd/exynos-lpass.c
Arnd Bergmann 22a96b85ea mfd: exynos-lpass: Mark PM functions as __maybe_unused
The newly added exynos lpass driver produces a build warning when
CONFIG_PM is disabled since the only callers of exynos_lpass_disable
are under an #ifdef:

drivers/mfd/exynos-lpass.c:93:13: error: 'exynos_lpass_disable' defined but not used [-Werror=unused-function]
 static void exynos_lpass_disable(struct exynos_lpass *lpass)

This removes the #ifdef and replaces it with __maybe_unused annotations
so the compiler can leave out the unused code silently with less
room for mistakes.

Fixes: 36c26760bba8 ("mfd: Add Samsung Exynos Low Power Audio Subsystem driver")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2016-10-04 15:48:04 +01:00

186 lines
5.1 KiB
C

/*
* Copyright (C) 2015 - 2016 Samsung Electronics Co., Ltd.
*
* Authors: Inha Song <ideal.song@samsung.com>
* Sylwester Nawrocki <s.nawrocki@samsung.com>
*
* Samsung Exynos SoC series Low Power Audio Subsystem driver.
*
* This module provides regmap for the Top SFR region and instantiates
* devices for IP blocks like DMAC, I2S, UART.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*/
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/mfd/syscon.h>
#include <linux/mfd/syscon/exynos5-pmu.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/types.h>
/* LPASS Top register definitions */
#define SFR_LPASS_CORE_SW_RESET 0x08
#define LPASS_SB_SW_RESET BIT(11)
#define LPASS_UART_SW_RESET BIT(10)
#define LPASS_PCM_SW_RESET BIT(9)
#define LPASS_I2S_SW_RESET BIT(8)
#define LPASS_WDT1_SW_RESET BIT(4)
#define LPASS_WDT0_SW_RESET BIT(3)
#define LPASS_TIMER_SW_RESET BIT(2)
#define LPASS_MEM_SW_RESET BIT(1)
#define LPASS_DMA_SW_RESET BIT(0)
#define SFR_LPASS_INTR_CA5_MASK 0x48
#define SFR_LPASS_INTR_CPU_MASK 0x58
#define LPASS_INTR_APM BIT(9)
#define LPASS_INTR_MIF BIT(8)
#define LPASS_INTR_TIMER BIT(7)
#define LPASS_INTR_DMA BIT(6)
#define LPASS_INTR_GPIO BIT(5)
#define LPASS_INTR_I2S BIT(4)
#define LPASS_INTR_PCM BIT(3)
#define LPASS_INTR_SLIMBUS BIT(2)
#define LPASS_INTR_UART BIT(1)
#define LPASS_INTR_SFR BIT(0)
struct exynos_lpass {
/* pointer to the Power Management Unit regmap */
struct regmap *pmu;
/* pointer to the LPASS TOP regmap */
struct regmap *top;
};
static void exynos_lpass_core_sw_reset(struct exynos_lpass *lpass, int mask)
{
unsigned int val = 0;
regmap_read(lpass->top, SFR_LPASS_CORE_SW_RESET, &val);
val &= ~mask;
regmap_write(lpass->top, SFR_LPASS_CORE_SW_RESET, val);
usleep_range(100, 150);
val |= mask;
regmap_write(lpass->top, SFR_LPASS_CORE_SW_RESET, val);
}
static void exynos_lpass_enable(struct exynos_lpass *lpass)
{
/* Unmask SFR, DMA and I2S interrupt */
regmap_write(lpass->top, SFR_LPASS_INTR_CA5_MASK,
LPASS_INTR_SFR | LPASS_INTR_DMA | LPASS_INTR_I2S);
regmap_write(lpass->top, SFR_LPASS_INTR_CPU_MASK,
LPASS_INTR_SFR | LPASS_INTR_DMA | LPASS_INTR_I2S);
/* Activate related PADs from retention state */
regmap_write(lpass->pmu, EXYNOS5433_PAD_RETENTION_AUD_OPTION,
EXYNOS5433_PAD_INITIATE_WAKEUP_FROM_LOWPWR);
exynos_lpass_core_sw_reset(lpass, LPASS_I2S_SW_RESET);
exynos_lpass_core_sw_reset(lpass, LPASS_DMA_SW_RESET);
exynos_lpass_core_sw_reset(lpass, LPASS_MEM_SW_RESET);
}
static void exynos_lpass_disable(struct exynos_lpass *lpass)
{
/* Mask any unmasked IP interrupt sources */
regmap_write(lpass->top, SFR_LPASS_INTR_CPU_MASK, 0);
regmap_write(lpass->top, SFR_LPASS_INTR_CA5_MASK, 0);
/* Deactivate related PADs from retention state */
regmap_write(lpass->pmu, EXYNOS5433_PAD_RETENTION_AUD_OPTION, 0);
}
static const struct regmap_config exynos_lpass_reg_conf = {
.reg_bits = 32,
.reg_stride = 4,
.val_bits = 32,
.max_register = 0xfc,
.fast_io = true,
};
static int exynos_lpass_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct exynos_lpass *lpass;
void __iomem *base_top;
struct resource *res;
lpass = devm_kzalloc(dev, sizeof(*lpass), GFP_KERNEL);
if (!lpass)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
base_top = devm_ioremap_resource(dev, res);
if (IS_ERR(base_top))
return PTR_ERR(base_top);
lpass->top = regmap_init_mmio(dev, base_top,
&exynos_lpass_reg_conf);
if (IS_ERR(lpass->top)) {
dev_err(dev, "LPASS top regmap initialization failed\n");
return PTR_ERR(lpass->top);
}
lpass->pmu = syscon_regmap_lookup_by_phandle(dev->of_node,
"samsung,pmu-syscon");
if (IS_ERR(lpass->pmu)) {
dev_err(dev, "Failed to lookup PMU regmap\n");
return PTR_ERR(lpass->pmu);
}
platform_set_drvdata(pdev, lpass);
exynos_lpass_enable(lpass);
return of_platform_populate(dev->of_node, NULL, NULL, dev);
}
static int __maybe_unused exynos_lpass_suspend(struct device *dev)
{
struct exynos_lpass *lpass = dev_get_drvdata(dev);
exynos_lpass_disable(lpass);
return 0;
}
static int __maybe_unused exynos_lpass_resume(struct device *dev)
{
struct exynos_lpass *lpass = dev_get_drvdata(dev);
exynos_lpass_enable(lpass);
return 0;
}
static SIMPLE_DEV_PM_OPS(lpass_pm_ops, exynos_lpass_suspend,
exynos_lpass_resume);
static const struct of_device_id exynos_lpass_of_match[] = {
{ .compatible = "samsung,exynos5433-lpass" },
{ },
};
MODULE_DEVICE_TABLE(of, exynos_lpass_of_match);
static struct platform_driver exynos_lpass_driver = {
.driver = {
.name = "exynos-lpass",
.pm = &lpass_pm_ops,
.of_match_table = exynos_lpass_of_match,
},
.probe = exynos_lpass_probe,
};
module_platform_driver(exynos_lpass_driver);
MODULE_DESCRIPTION("Samsung Low Power Audio Subsystem driver");
MODULE_LICENSE("GPL v2");