Re: [PATCH v2 3/4] drivers: reset: Add STM32 reset driver

From: Arnd Bergmann
Date: Fri Jul 22 2016 - 15:26:12 EST

On Thursday, July 21, 2016 7:16:02 PM CEST Paul Gortmaker wrote:

> > > ...we probably don't need module.h here or any of the other
> > > MODULE_<blah> tags/macros either. Use the builtin for the
> > > register and all should be good.
> >
> > I wonder if we should have separate symbols for each reset driver
> > instead. Those could be allowed to be tristate, and could also
> > be enabled for compile testing on other architectures.
>
> I'm not quite clear on what you mean by the above. Maybe if you have a
> pointer to an example -- say like the work you mention below -- then
> I'll understand what you have in mind.

I mean instead of having each driver compiled implicitly when the
ARCH_* symbol is enabled, make the drivers user-selectable
and just default to 'y' when the platform is enabled. This would
let us actually use modular reset drivers where appropriate
(which might be nowhere, but at least we wouldn't forbid it
for no reason).

Another annoying thing is that all platforms today need to
select two symbols

select ARCH_HAS_RESET_CONTROLLER
select RESET_CONTROLLER

in order to actually build the driver, and the second one is
user-selectable, meaning you can still disable all of them today,
just not individual drivers.

The patch below is something I did a long time ago for my
randconfig test branch and have kept forward-ported. It's
probably bitrotten by now and wrong, but you should get the
idea.

Arnd

commit ee86e4aad86ddce56a5858ddb5bb62d08b54e8f0
Author: Arnd Bergmann <arnd@xxxxxxxx>
Date: Tue Feb 24 15:30:30 2015 +0100

rework RESET_CONTROLLER handling

arch/arm/mach-berlin/Kconfig | 1 -
arch/arm/mach-imx/Kconfig | 1 -
arch/arm/mach-mmp/Kconfig | 2 ++
arch/arm/mach-prima2/Kconfig | 3 +--
arch/arm/mach-rockchip/Kconfig | 2 +-
arch/arm/mach-sti/Kconfig | 2 --
arch/arm/mach-sunxi/Kconfig | 1 -
arch/arm/mach-sunxi/sunxi.c | 2 +-
arch/arm/mach-tegra/Kconfig | 1 -
drivers/dma/Kconfig | 1 -
drivers/gpu/drm/rockchip/Kconfig | 1 -
drivers/gpu/drm/tegra/Kconfig | 1 -
drivers/gpu/ipu-v3/Kconfig | 1 -
drivers/i2c/busses/Kconfig | 1 -
drivers/phy/Kconfig | 6 ++----
drivers/pinctrl/sunxi/Kconfig | 2 --
drivers/reset/Kconfig | 27 ++++++++++++++++-----------
drivers/reset/Makefile | 10 +++++-----
drivers/reset/sti/Kconfig | 22 +++++++++++-----------
drivers/reset/sti/Makefile | 8 ++++----
drivers/soc/mediatek/Kconfig | 1 -
drivers/spi/Kconfig | 7 ++-----
drivers/thermal/Kconfig | 1 -
drivers/usb/phy/Kconfig | 1 -
include/linux/reset.h | 34 +++++++++++++++++++++++++---------
sound/soc/tegra/Kconfig | 1 -
26 files changed, 70 insertions(+), 70 deletions(-)

diff --git a/arch/arm/mach-berlin/Kconfig b/arch/arm/mach-berlin/Kconfig
index 63ab1d368625..9ca262538e91 100644
--- a/arch/arm/mach-berlin/Kconfig
+++ b/arch/arm/mach-berlin/Kconfig
@@ -1,7 +1,6 @@
menuconfig ARCH_BERLIN
bool "Marvell Berlin SoCs"
depends on ARCH_MULTI_V7
- select ARCH_HAS_RESET_CONTROLLER
select ARM_GIC
select DW_APB_ICTL
select DW_APB_TIMER_OF
diff --git a/arch/arm/mach-imx/Kconfig b/arch/arm/mach-imx/Kconfig
index ee9a318cab31..e72c5dcb2ea3 100644
--- a/arch/arm/mach-imx/Kconfig
+++ b/arch/arm/mach-imx/Kconfig
@@ -56,7 +56,6 @@ config HAVE_IMX_MMDC

config HAVE_IMX_SRC
def_bool y if SMP
- select ARCH_HAS_RESET_CONTROLLER

config IMX_HAVE_IOMUX_V1
bool
diff --git a/arch/arm/mach-mmp/Kconfig b/arch/arm/mach-mmp/Kconfig
index 94500bed56ab..e2130e051d7f 100644
--- a/arch/arm/mach-mmp/Kconfig
+++ b/arch/arm/mach-mmp/Kconfig
@@ -111,6 +111,7 @@ config MACH_MMP_DT
select PINCTRL_SINGLE
select COMMON_CLK
select ARCH_HAS_RESET_CONTROLLER
+ select RESET_CONTROLLER
select CPU_MOHAWK
help
Include support for Marvell MMP2 based platforms using
@@ -123,6 +124,7 @@ config MACH_MMP2_DT
select PINCTRL
select PINCTRL_SINGLE
select ARCH_HAS_RESET_CONTROLLER
+ select RESET_CONTROLLER
select CPU_PJ4
help
Include support for Marvell MMP2 based platforms using
diff --git a/arch/arm/mach-prima2/Kconfig b/arch/arm/mach-prima2/Kconfig
index 85e874a97337..6a28cfa89069 100644
--- a/arch/arm/mach-prima2/Kconfig
+++ b/arch/arm/mach-prima2/Kconfig
@@ -1,14 +1,13 @@
menuconfig ARCH_SIRF
bool "CSR SiRF"
depends on ARCH_MULTI_V7
- select ARCH_HAS_RESET_CONTROLLER
- select RESET_CONTROLLER
select GENERIC_IRQ_CHIP
select GPIOLIB
select NO_IOPORT_MAP
select REGMAP
select PINCTRL
select PINCTRL_SIRF
+ select RESET_CONTROLLER
help
Support for CSR SiRFprimaII/Marco/Polo platforms

diff --git a/arch/arm/mach-rockchip/Kconfig b/arch/arm/mach-rockchip/Kconfig
index 9ad84cd01ba0..b67dfc23ddbb 100644
--- a/arch/arm/mach-rockchip/Kconfig
+++ b/arch/arm/mach-rockchip/Kconfig
@@ -3,7 +3,6 @@ config ARCH_ROCKCHIP
depends on ARCH_MULTI_V7
select PINCTRL
select PINCTRL_ROCKCHIP
- select ARCH_HAS_RESET_CONTROLLER
select ARM_AMBA
select ARM_GIC
select CACHE_L2X0
@@ -13,6 +12,7 @@ config ARCH_ROCKCHIP
select HAVE_ARM_TWD if SMP
select DW_APB_TIMER_OF
select REGULATOR if PM
+ select RESET_CONTROLLER
select ROCKCHIP_TIMER
select ARM_GLOBAL_TIMER
select CLKSRC_ARM_GLOBAL_TIMER_SCHED_CLOCK
diff --git a/arch/arm/mach-sti/Kconfig b/arch/arm/mach-sti/Kconfig
index 119e1108b1f8..7ceb3f9a0ca5 100644
--- a/arch/arm/mach-sti/Kconfig
+++ b/arch/arm/mach-sti/Kconfig
@@ -8,7 +8,6 @@ menuconfig ARCH_STI
select PINCTRL
select PINCTRL_ST
select MFD_SYSCON
- select ARCH_HAS_RESET_CONTROLLER
select HAVE_ARM_SCU if SMP
select GPIOLIB
select ARM_ERRATA_754322
@@ -16,7 +15,6 @@ menuconfig ARCH_STI
select ARM_ERRATA_775420
select PL310_ERRATA_753970 if CACHE_L2X0
select PL310_ERRATA_769419 if CACHE_L2X0
- select RESET_CONTROLLER
help
Include support for STMicroelectronics' STiH415/416, STiH407/10 and
STiH418 family SoCs using the Device Tree for discovery. More
diff --git a/arch/arm/mach-sunxi/Kconfig b/arch/arm/mach-sunxi/Kconfig
index 096ed216c6d5..b6427c08a7ff 100644
--- a/arch/arm/mach-sunxi/Kconfig
+++ b/arch/arm/mach-sunxi/Kconfig
@@ -1,7 +1,6 @@
menuconfig ARCH_SUNXI
bool "Allwinner SoCs"
depends on ARCH_MULTI_V7
- select ARCH_HAS_RESET_CONTROLLER
select CLKSRC_MMIO
select GENERIC_IRQ_CHIP
select GPIOLIB
diff --git a/arch/arm/mach-sunxi/sunxi.c b/arch/arm/mach-sunxi/sunxi.c
index 95dca8c2c9ed..1f7093166792 100644
--- a/arch/arm/mach-sunxi/sunxi.c
+++ b/arch/arm/mach-sunxi/sunxi.c
@@ -39,7 +39,7 @@ extern void __init sun6i_reset_init(void);
static void __init sun6i_timer_init(void)
{
of_clk_init(NULL);
- if (IS_ENABLED(CONFIG_RESET_CONTROLLER))
+ if (IS_ENABLED(CONFIG_RESET_SUNXI))
sun6i_reset_init();
clocksource_probe();
}
diff --git a/arch/arm/mach-tegra/Kconfig b/arch/arm/mach-tegra/Kconfig
index 329f01c5b6f8..6986fee549cb 100644
--- a/arch/arm/mach-tegra/Kconfig
+++ b/arch/arm/mach-tegra/Kconfig
@@ -10,7 +10,6 @@ menuconfig ARCH_TEGRA
select HAVE_ARM_TWD if SMP
select PINCTRL
select PM_OPP
- select ARCH_HAS_RESET_CONTROLLER
select RESET_CONTROLLER
select SOC_BUS
help
diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index 739f797b40d9..675dcef0ac85 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -159,7 +159,6 @@ config DMA_SUN4I
config DMA_SUN6I
tristate "Allwinner A31 SoCs DMA support"
depends on MACH_SUN6I || MACH_SUN8I || COMPILE_TEST
- depends on RESET_CONTROLLER
select DMA_ENGINE
select DMA_VIRTUAL_CHANNELS
help
diff --git a/drivers/gpu/drm/rockchip/Kconfig b/drivers/gpu/drm/rockchip/Kconfig
index 3c58669a06ce..6f7f9c59f05b 100644
--- a/drivers/gpu/drm/rockchip/Kconfig
+++ b/drivers/gpu/drm/rockchip/Kconfig
@@ -1,7 +1,6 @@
config DRM_ROCKCHIP
tristate "DRM Support for Rockchip"
depends on DRM && ROCKCHIP_IOMMU
- depends on RESET_CONTROLLER
select DRM_GEM_CMA_HELPER
select DRM_KMS_HELPER
select DRM_PANEL
diff --git a/drivers/gpu/drm/tegra/Kconfig b/drivers/gpu/drm/tegra/Kconfig
index 63ebb154b9b5..bbf5a4b7e0b6 100644
--- a/drivers/gpu/drm/tegra/Kconfig
+++ b/drivers/gpu/drm/tegra/Kconfig
@@ -3,7 +3,6 @@ config DRM_TEGRA
depends on ARCH_TEGRA || (ARM && COMPILE_TEST)
depends on COMMON_CLK
depends on DRM
- depends on RESET_CONTROLLER
select DRM_KMS_HELPER
select DRM_MIPI_DSI
select DRM_PANEL
diff --git a/drivers/gpu/ipu-v3/Kconfig b/drivers/gpu/ipu-v3/Kconfig
index aefdff95356d..08766c6e7856 100644
--- a/drivers/gpu/ipu-v3/Kconfig
+++ b/drivers/gpu/ipu-v3/Kconfig
@@ -1,7 +1,6 @@
config IMX_IPUV3_CORE
tristate "IPUv3 core support"
depends on SOC_IMX5 || SOC_IMX6Q || ARCH_MULTIPLATFORM
- depends on RESET_CONTROLLER
select GENERIC_IRQ_CHIP
help
Choose this if you have a i.MX5/6 system and want to use the Image
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 5c3993b26129..5913f7c7318a 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -891,7 +891,6 @@ config I2C_STU300

config I2C_SUN6I_P2WI
tristate "Allwinner sun6i internal P2WI controller"
- depends on RESET_CONTROLLER
depends on MACH_SUN6I || COMPILE_TEST
help
If you say yes to this option, support will be included for the
diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
index 19bff3a10f69..f685397fd3ac 100644
--- a/drivers/phy/Kconfig
+++ b/drivers/phy/Kconfig
@@ -26,7 +26,8 @@ config PHY_BCM_NS_USB2

config PHY_BERLIN_USB
tristate "Marvell Berlin USB PHY Driver"
- depends on ARCH_BERLIN && RESET_CONTROLLER && HAS_IOMEM && OF
+ depends on ARCH_BERLIN || COMPILE_TEST
+ depends on HAS_IOMEM && OF
select GENERIC_PHY
help
Enable this to support the USB PHY on Marvell Berlin SoCs.
@@ -255,7 +256,6 @@ config PHY_HI6220_USB
config PHY_SUN4I_USB
tristate "Allwinner sunxi SoC USB PHY driver"
depends on ARCH_SUNXI && HAS_IOMEM && OF
- depends on RESET_CONTROLLER
depends on EXTCON
depends on POWER_SUPPLY
select GENERIC_PHY
@@ -269,7 +269,6 @@ config PHY_SUN4I_USB
config PHY_SUN9I_USB
tristate "Allwinner sun9i SoC USB PHY driver"
depends on ARCH_SUNXI && HAS_IOMEM && OF
- depends on RESET_CONTROLLER
depends on USB_SUPPORT
select USB_COMMON
select GENERIC_PHY
@@ -395,7 +394,6 @@ config PHY_XGENE

config PHY_STIH407_USB
tristate "STMicroelectronics USB2 picoPHY driver for STiH407 family"
- depends on RESET_CONTROLLER
depends on ARCH_STI || COMPILE_TEST
select GENERIC_PHY
help
diff --git a/drivers/pinctrl/sunxi/Kconfig b/drivers/pinctrl/sunxi/Kconfig
index aaf075b972f5..c55a6750f4b8 100644
--- a/drivers/pinctrl/sunxi/Kconfig
+++ b/drivers/pinctrl/sunxi/Kconfig
@@ -27,7 +27,6 @@ config PINCTRL_SUN6I_A31S

config PINCTRL_SUN6I_A31_R
def_bool MACH_SUN6I
- depends on RESET_CONTROLLER
select PINCTRL_SUNXI

config PINCTRL_SUN7I_A20
@@ -48,7 +47,6 @@ config PINCTRL_SUN8I_A83T

config PINCTRL_SUN8I_A23_R
def_bool MACH_SUN8I
- depends on RESET_CONTROLLER
select PINCTRL_SUNXI

config PINCTRL_SUN8I_H3
diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
index 4be1b8c21f6f..05d6afc8cff8 100644
--- a/drivers/reset/Kconfig
+++ b/drivers/reset/Kconfig
@@ -1,18 +1,23 @@
-config ARCH_HAS_RESET_CONTROLLER
+config RESET_CONTROLLER
bool

-menuconfig RESET_CONTROLLER
- bool "Reset Controller Support"
- default y if ARCH_HAS_RESET_CONTROLLER
- help
- Generic Reset Controller support.
+menu "Reset Controller Support"
+ depends on ARCH_HAS_RESET_CONTROLLER || COMPILE_TEST

- This framework is designed to abstract reset handling of devices
- via GPIOs or SoC-internal reset controller modules.
+config RESET_SOCFPGA
+ bool "Altera SOCFPGA reset controller" if COMPILE_TEST
+ default ARCH_SOCFPGA
+ select RESET_CONTROLLER

- If unsure, say no.
+config RESET_BERLIN
+ bool "Marvell Berlin reset controller" if COMPILE_TEST
+ default ARCH_BERLIN
+ select RESET_CONTROLLER

-if RESET_CONTROLLER
+config RESET_SUNXI
+ bool "Allwinner reset controller" if COMPILE_TEST
+ default ARCH_SUNXI
+ select RESET_CONTROLLER

config RESET_OXNAS
bool
@@ -30,4 +35,4 @@ config TI_SYSCON_RESET
source "drivers/reset/sti/Kconfig"
source "drivers/reset/hisilicon/Kconfig"

-endif
+endmenu
diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
index 5d65a93d3c43..7e610e409dae 100644
--- a/drivers/reset/Makefile
+++ b/drivers/reset/Makefile
@@ -1,11 +1,11 @@
obj-y += core.o
-obj-$(CONFIG_ARCH_LPC18XX) += reset-lpc18xx.o
-obj-$(CONFIG_ARCH_SOCFPGA) += reset-socfpga.o
-obj-$(CONFIG_ARCH_BERLIN) += reset-berlin.o
obj-$(CONFIG_MACH_PISTACHIO) += reset-pistachio.o
+obj-$(CONFIG_RESET_SOCFPGA) += reset-socfpga.o
+obj-$(CONFIG_RESET_BERLIN) += reset-berlin.o
+obj-$(CONFIG_RESET_HISI) += hisilicon/
obj-$(CONFIG_ARCH_MESON) += reset-meson.o
-obj-$(CONFIG_ARCH_SUNXI) += reset-sunxi.o
-obj-$(CONFIG_ARCH_STI) += sti/
+obj-$(CONFIG_RESET_SUNXI) += reset-sunxi.o
+obj-$(CONFIG_RESET_STI_SYSCFG) += sti/
obj-$(CONFIG_ARCH_HISI) += hisilicon/
obj-$(CONFIG_ARCH_ZYNQ) += reset-zynq.o
obj-$(CONFIG_ATH79) += reset-ath79.o
diff --git a/drivers/reset/sti/Kconfig b/drivers/reset/sti/Kconfig
index 613178553612..20ea1a147afb 100644
--- a/drivers/reset/sti/Kconfig
+++ b/drivers/reset/sti/Kconfig
@@ -1,18 +1,18 @@
-if ARCH_STI
+if ARCH_STI || COMPILE_TEST

-config STI_RESET_SYSCFG
+config RESET_STI_SYSCFG
bool

-config STIH415_RESET
- bool
- select STI_RESET_SYSCFG
+config RESET_STIH415
+ bool "STmicroelectronics STiH415 reset controller" if COMPILE_TEST
+ select RESET_STI_SYSCFG

-config STIH416_RESET
- bool
- select STI_RESET_SYSCFG
+config RESET_STIH416
+ bool "STmicroelectronics STiH416 reset controller" if COMPILE_TEST
+ select RESET_STI_SYSCFG

-config STIH407_RESET
- bool
- select STI_RESET_SYSCFG
+config RESET_STIH407
+ bool "STmicroelectronics STiH407 reset controller" if COMPILE_TEST
+ select RESET_STI_SYSCFG

endif
diff --git a/drivers/reset/sti/Makefile b/drivers/reset/sti/Makefile
index dc85dfbe56a9..445bdddf45b9 100644
--- a/drivers/reset/sti/Makefile
+++ b/drivers/reset/sti/Makefile
@@ -1,5 +1,5 @@
-obj-$(CONFIG_STI_RESET_SYSCFG) += reset-syscfg.o
+obj-$(CONFIG_RESET_STI_SYSCFG) += reset-syscfg.o

-obj-$(CONFIG_STIH415_RESET) += reset-stih415.o
-obj-$(CONFIG_STIH416_RESET) += reset-stih416.o
-obj-$(CONFIG_STIH407_RESET) += reset-stih407.o
+obj-$(CONFIG_RESET_STIH415) += reset-stih415.o
+obj-$(CONFIG_RESET_STIH416) += reset-stih416.o
+obj-$(CONFIG_RESET_STIH407) += reset-stih407.o
diff --git a/drivers/soc/mediatek/Kconfig b/drivers/soc/mediatek/Kconfig
index 0a4ea809a61b..8e47d52766b7 100644
--- a/drivers/soc/mediatek/Kconfig
+++ b/drivers/soc/mediatek/Kconfig
@@ -13,7 +13,6 @@ config MTK_INFRACFG
config MTK_PMIC_WRAP
tristate "MediaTek PMIC Wrapper Support"
depends on ARCH_MEDIATEK
- depends on RESET_CONTROLLER
select REGMAP
help
Say yes here to add support for MediaTek PMIC Wrapper found
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index c91493613238..c606e136f3c6 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -575,7 +575,6 @@ config SPI_SH_HSPI
config SPI_SIRF
tristate "CSR SiRFprimaII SPI controller"
depends on SIRF_DMA
- depends on RESET_CONTROLLER
select SPI_BITBANG
help
SPI driver for CSR SiRFprimaII SoCs
@@ -596,7 +595,6 @@ config SPI_SUN4I
config SPI_SUN6I
tristate "Allwinner A31 SPI controller"
depends on ARCH_SUNXI || COMPILE_TEST
- depends on RESET_CONTROLLER
help
This enables using the SPI controller on the Allwinner A31 SoCs.

@@ -610,7 +608,7 @@ config SPI_MXS
config SPI_TEGRA114
tristate "NVIDIA Tegra114 SPI Controller"
depends on (ARCH_TEGRA && TEGRA20_APB_DMA) || COMPILE_TEST
- depends on RESET_CONTROLLER && HAS_DMA
+ depends on HAS_DMA
help
SPI driver for NVIDIA Tegra114 SPI Controller interface. This controller
is different than the older SoCs SPI controller and also register interface
@@ -619,7 +617,6 @@ config SPI_TEGRA114
config SPI_TEGRA20_SFLASH
tristate "Nvidia Tegra20 Serial flash Controller"
depends on ARCH_TEGRA || COMPILE_TEST
- depends on RESET_CONTROLLER
help
SPI driver for Nvidia Tegra20 Serial flash Controller interface.
The main usecase of this controller is to use spi flash as boot
@@ -628,7 +625,7 @@ config SPI_TEGRA20_SFLASH
config SPI_TEGRA20_SLINK
tristate "Nvidia Tegra20/Tegra30 SLINK Controller"
depends on (ARCH_TEGRA && TEGRA20_APB_DMA) || COMPILE_TEST
- depends on RESET_CONTROLLER && HAS_DMA
+ depends on HAS_DMA
help
SPI driver for Nvidia Tegra20/Tegra30 SLINK Controller interface.

diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index 8303823d7f07..e4e59701f7df 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -207,7 +207,6 @@ config SPEAR_THERMAL
config ROCKCHIP_THERMAL
tristate "Rockchip thermal driver"
depends on ARCH_ROCKCHIP || COMPILE_TEST
- depends on RESET_CONTROLLER
depends on HAS_IOMEM
help
Rockchip thermal driver provides support for Temperature sensor
diff --git a/drivers/usb/phy/Kconfig b/drivers/usb/phy/Kconfig
index 4b5e5c8ecefd..5538e04c3356 100644
--- a/drivers/usb/phy/Kconfig
+++ b/drivers/usb/phy/Kconfig
@@ -146,7 +146,6 @@ config USB_MSM_OTG
tristate "Qualcomm on-chip USB OTG controller support"
depends on (USB || USB_GADGET) && (ARCH_QCOM || COMPILE_TEST)
depends on USB_GADGET || !USB_GADGET # if USB_GADGET=m, this can't be 'y'
- depends on RESET_CONTROLLER
depends on EXTCON
select USB_PHY
select QCOM_TCSR if ARCH_QCOM
diff --git a/include/linux/reset.h b/include/linux/reset.h
index 5daff15722d3..4ec41b11e090 100644
--- a/include/linux/reset.h
+++ b/include/linux/reset.h
@@ -27,33 +27,41 @@ static inline int device_reset_optional(struct device *dev)

#else

+#include <linux/device.h>
+#include <linux/of.h>
+
+static inline int __must_check device_reset(struct device *dev)
+{
+ return -ENOSYS;
+}
+
static inline int reset_control_reset(struct reset_control *rstc)
{
- WARN_ON(1);
+ WARN_ON(rstc != NULL);
return 0;
}

static inline int reset_control_assert(struct reset_control *rstc)
{
- WARN_ON(1);
+ WARN_ON(rstc != NULL);
return 0;
}

static inline int reset_control_deassert(struct reset_control *rstc)
{
- WARN_ON(1);
+ WARN_ON(rstc != NULL);
return 0;
}

static inline int reset_control_status(struct reset_control *rstc)
{
- WARN_ON(1);
+ WARN_ON(rstc != NULL);
return 0;
}

static inline void reset_control_put(struct reset_control *rstc)
{
- WARN_ON(1);
+ WARN_ON(rstc != NULL);
}

static inline int __must_check device_reset(struct device *dev)
@@ -64,21 +72,24 @@ static inline int __must_check device_reset(struct device *dev)

static inline int device_reset_optional(struct device *dev)
{
- return -ENOTSUPP;
+ if (of_property_read_bool(dev->of_node, "resets"))
+ return -ENOSYS;
+
+ return 0;
}

static inline struct reset_control *__of_reset_control_get(
struct device_node *node,
const char *id, int index, int shared)
{
- return ERR_PTR(-ENOTSUPP);
+ return ERR_PTR(device_reset_optional(dev));
}

static inline struct reset_control *__devm_reset_control_get(
struct device *dev,
const char *id, int index, int shared)
{
- return ERR_PTR(-ENOTSUPP);
+ return ERR_PTR(device_reset_optional(dev));
}

#endif /* CONFIG_RESET_CONTROLLER */
@@ -330,10 +341,15 @@ static inline struct reset_control *reset_control_get(
return reset_control_get_exclusive(dev, id);
}

+/*
+ * We intentionally return NULL here when no resets are specified
+ * or when building without DT, which is interpreted as 'success'
+ * if reset controller support is left out from the kernel.
+ */
static inline struct reset_control *reset_control_get_optional(
struct device *dev, const char *id)
{
- return reset_control_get_optional_exclusive(dev, id);
+ return __of_reset_control_get(dev ? dev->of_node : NULL, id, 0, 0);
}

static inline struct reset_control *of_reset_control_get(
diff --git a/sound/soc/tegra/Kconfig b/sound/soc/tegra/Kconfig
index a6768f832c6f..70f58bd43a56 100644
--- a/sound/soc/tegra/Kconfig
+++ b/sound/soc/tegra/Kconfig
@@ -2,7 +2,6 @@ config SND_SOC_TEGRA
tristate "SoC Audio for the Tegra System-on-Chip"
depends on (ARCH_TEGRA && TEGRA20_APB_DMA) || COMPILE_TEST
depends on COMMON_CLK
- depends on RESET_CONTROLLER
select REGMAP_MMIO
select SND_SOC_GENERIC_DMAENGINE_PCM
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