[RFC PATCH 0/7] reset: make RESET_CONTROLLER a select'ed option

[RFC PATCH 0/7] reset: make RESET_CONTROLLER a select'ed option

[Masahiro Yamada]

When I was implementing a new reset controller for my SoCs,
I struggled to make my sub-menu shown under the reset
controller menu.
I noticed the Kconfig in reset sub-system are screwed up due to two
config options (ARCH_HAS_RESET_CONTROLLER and RESET_CONTROLLER).

I think only the former should be select'ed by relevant SoCs,
but in fact the latter is also select'ed here and there.
Mixing "select" to a user-configurable option is a mess.

Finally, I started to wonder whether it could be more simpler?

The first patch drops ARCH_HAS_RESET_CONTROLLER.
RESET_CONTROLLER should be directly selected by SoCs.

The rest of this series are minor clean ups in other
sub-systems.
I can postpone them if changes over cross sub-systems
are not preferred.



Masahiro Yamada (7):
  reset: drop ARCH_HAS_RESET_CONTROLLER
  spi: sunxi: remove redundant "depends on RESET_CONTROLLER"
  spi: tegra: remove redundant "depends on RESET_CONTROLLER"
  pinctrl: sunxi: remove redundant "depends on RESET_CONTROLLER"
  drm/sti: replace "select RESET_CONTROLLER" with "depends on ..."
  drm/rockchip: remove redundant "depends on RESET_CONTROLLER"
  drm/tegra: tegra: remove redundant "depends on RESET_CONTROLLER"

 arch/arm/Kconfig                 |  3 +--
 arch/arm/mach-berlin/Kconfig     |  2 +-
 arch/arm/mach-imx/Kconfig        |  2 +-
 arch/arm/mach-mmp/Kconfig        |  4 ++--
 arch/arm/mach-prima2/Kconfig     |  2 +-
 arch/arm/mach-rockchip/Kconfig   |  2 +-
 arch/arm/mach-sti/Kconfig        |  1 -
 arch/arm/mach-sunxi/Kconfig      |  1 -
 arch/arm/mach-tegra/Kconfig      |  1 -
 arch/arm64/Kconfig.platforms     |  3 +--
 arch/mips/Kconfig                |  4 +---
 drivers/gpu/drm/rockchip/Kconfig |  1 -
 drivers/gpu/drm/sti/Kconfig      |  4 ++--
 drivers/gpu/drm/tegra/Kconfig    |  1 -
 drivers/pinctrl/sunxi/Kconfig    |  2 --
 drivers/reset/Kconfig            | 12 +++++++-----
 drivers/reset/sti/Kconfig        |  1 -
 drivers/spi/Kconfig              |  6 ++----
 18 files changed, 20 insertions(+), 32 deletions(-)

-- 
1.9.1

[RFC PATCH 4/7] pinctrl: sunxi: remove redundant "depends on RESET_CONTROLLER"

[Masahiro Yamada]

ARCH_SUNXI selects RESET_CONTROLLER.
The dependency "depends on RESET_CONTROLLER" is already met.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

 drivers/pinctrl/sunxi/Kconfig | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/pinctrl/sunxi/Kconfig b/drivers/pinctrl/sunxi/Kconfig
index e68fd95..50bd2e3 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_COMMON
 
 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_COMMON
 
 config PINCTRL_SUN9I_A80
-- 
1.9.1

Re: [RFC PATCH 4/7] pinctrl: sunxi: remove redundant "depends on RESET_CONTROLLER"

[Linus Walleij]

On Thu, Nov 5, 2015 at 12:15 PM, Masahiro Yamada
<yamada.masahiro@socionext.com> wrote:

> ARCH_SUNXI selects RESET_CONTROLLER.
> The dependency "depends on RESET_CONTROLLER" is already met.
>
> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

NACK, this pin controller needs that as dependency, I don't worry
that it's overspecified.

They both do this:
#include <linux/reset.h>

And the object should specify its dependencies, not rely on them
being implicitly available.

The dep is there for human readers too, not just machines. And to
them, this is helpful information.

Yours,
Linus Walleij

Re: [RFC PATCH 4/7] pinctrl: sunxi: remove redundant "depends on RESET_CONTROLLER"

[Linus Walleij]

On Thu, Nov 5, 2015 at 2:40 PM, Linus Walleij <linus.walleij@linaro.org> wrote:
> On Thu, Nov 5, 2015 at 12:15 PM, Masahiro Yamada
> <yamada.masahiro@socionext.com> wrote:
>
>> ARCH_SUNXI selects RESET_CONTROLLER.
>> The dependency "depends on RESET_CONTROLLER" is already met.
>>
>> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
>
> NACK, this pin controller needs that as dependency, I don't worry
> that it's overspecified.
>
> They both do this:
> #include <linux/reset.h>

You could of course replace the depends with select in this
file so the menu options don't get hidden, as seems to be
the problem as described in 0/7.

Yours,
Linus Walleij

Re: [RFC PATCH 4/7] pinctrl: sunxi: remove redundant "depends on RESET_CONTROLLER"

[Masahiro Yamada]

Hi Linus

2015-11-05 22:40 GMT+09:00 Linus Walleij <linus.walleij@linaro.org>:
> On Thu, Nov 5, 2015 at 12:15 PM, Masahiro Yamada
> <yamada.masahiro@socionext.com> wrote:
>
>> ARCH_SUNXI selects RESET_CONTROLLER.
>> The dependency "depends on RESET_CONTROLLER" is already met.
>>
>> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
>
> NACK, this pin controller needs that as dependency, I don't worry
> that it's overspecified.
>
> They both do this:
> #include <linux/reset.h>
>
> And the object should specify its dependencies, not rely on them
> being implicitly available.
>
> The dep is there for human readers too, not just machines. And to
> them, this is helpful information.

How strict we should follow this rule?

Many drivers depend on OF, but do they all have "depends on OF"?





-- 
Best Regards
Masahiro Yamada

Re: [RFC PATCH 4/7] pinctrl: sunxi: remove redundant "depends on RESET_CONTROLLER"

[Linus Walleij]

On Mon, Nov 16, 2015 at 4:40 AM, Masahiro Yamada
<yamada.masahiro@socionext.com> wrote:
> 2015-11-05 22:40 GMT+09:00 Linus Walleij <linus.walleij@linaro.org>:
>> On Thu, Nov 5, 2015 at 12:15 PM, Masahiro Yamada
>> <yamada.masahiro@socionext.com> wrote:
>>
>>> ARCH_SUNXI selects RESET_CONTROLLER.
>>> The dependency "depends on RESET_CONTROLLER" is already met.
>>>
>>> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
>>
>> NACK, this pin controller needs that as dependency, I don't worry
>> that it's overspecified.
>>
>> They both do this:
>> #include <linux/reset.h>
>>
>> And the object should specify its dependencies, not rely on them
>> being implicitly available.
>>
>> The dep is there for human readers too, not just machines. And to
>> them, this is helpful information.
>
> How strict we should follow this rule?
>
> Many drivers depend on OF, but do they all have "depends on OF"?

I think they should, and if they are in my subsystems I consider
it a bug if they don't have this dependency. Also it is a very common
reason why test compiles fail.

Yours,
Linus Walleij

Re: [RFC PATCH 0/7] reset: make RESET_CONTROLLER a select'ed option

[Arnd Bergmann]

On Thursday 05 November 2015 20:15:21 Masahiro Yamada wrote:
> When I was implementing a new reset controller for my SoCs,
> I struggled to make my sub-menu shown under the reset
> controller menu.
> I noticed the Kconfig in reset sub-system are screwed up due to two
> config options (ARCH_HAS_RESET_CONTROLLER and RESET_CONTROLLER).
> 
> I think only the former should be select'ed by relevant SoCs,
> but in fact the latter is also select'ed here and there.
> Mixing "select" to a user-configurable option is a mess.
> 
> Finally, I started to wonder whether it could be more simpler?
> 
> The first patch drops ARCH_HAS_RESET_CONTROLLER.
> RESET_CONTROLLER should be directly selected by SoCs.
> 
> The rest of this series are minor clean ups in other
> sub-systems.
> I can postpone them if changes over cross sub-systems
> are not preferred.

Thanks a lot for picking up this topic! It has been annoying me
for a while and I have submitted an experimental patch some time
ago, but not finished it myself.

For some reason, I only see a subset of your patches here (patch 1, 4 and 6),
so I don't know exactly what you did. For reference, you can find
my original patch below. Please check if I did things that your
series doesn't do, and whether those are still needed.

	Arnd

commit 7983ffe5e07a5aac0c9bdd657858e3b2b9842b30
Author: Arnd Bergmann <arnd-r2nGTMty4D4@public.gmane.org>
Date:   Tue Feb 24 15:30:30 2015 +0100

    rework RESET_CONTROLLER handling

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 2f5f6d0b09a6..ab137ae8dcc8 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -319,6 +319,7 @@ choice
 
 config ARCH_MULTIPLATFORM
 	bool "Allow multiple platforms to be selected"
+	select ARCH_HAS_RESET_CONTROLLER
 	select ARCH_WANT_OPTIONAL_GPIOLIB
 	select ARM_HAS_SG_CHAIN
 	select ARM_PATCH_PHYS_VIRT
diff --git a/arch/arm/mach-berlin/Kconfig b/arch/arm/mach-berlin/Kconfig
index 344434ca366c..2dc8f3df39e6 100644
--- a/arch/arm/mach-berlin/Kconfig
+++ b/arch/arm/mach-berlin/Kconfig
@@ -1,6 +1,5 @@
 menuconfig ARCH_BERLIN
 	bool "Marvell Berlin SoCs" if ARCH_MULTI_V7
-	select ARCH_HAS_RESET_CONTROLLER
 	select ARCH_REQUIRE_GPIOLIB
 	select ARM_GIC
 	select DW_APB_ICTL
diff --git a/arch/arm/mach-imx/Kconfig b/arch/arm/mach-imx/Kconfig
index 8ceda2844c4f..1b1134adc188 100644
--- a/arch/arm/mach-imx/Kconfig
+++ b/arch/arm/mach-imx/Kconfig
@@ -58,7 +58,6 @@ 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 4773fe1d8b3f..116502d776ab 100644
--- a/arch/arm/mach-mmp/Kconfig
+++ b/arch/arm/mach-mmp/Kconfig
@@ -113,6 +113,7 @@ 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
@@ -125,6 +126,7 @@ 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 9ab8932403e5..00adfc4a5cd6 100644
--- a/arch/arm/mach-prima2/Kconfig
+++ b/arch/arm/mach-prima2/Kconfig
@@ -1,12 +1,12 @@
 menuconfig ARCH_SIRF
 	bool "CSR SiRF" if ARCH_MULTI_V7
-	select ARCH_HAS_RESET_CONTROLLER
 	select ARCH_REQUIRE_GPIOLIB
 	select GENERIC_IRQ_CHIP
 	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 ae4eb7cc4bcc..17d2df427c3c 100644
--- a/arch/arm/mach-rockchip/Kconfig
+++ b/arch/arm/mach-rockchip/Kconfig
@@ -2,7 +2,6 @@ config ARCH_ROCKCHIP
 	bool "Rockchip RK2928 and RK3xxx SOCs" if ARCH_MULTI_V7
 	select PINCTRL
 	select PINCTRL_ROCKCHIP
-	select ARCH_HAS_RESET_CONTROLLER
 	select ARCH_REQUIRE_GPIOLIB
 	select ARM_AMBA
 	select ARM_GIC
@@ -12,6 +11,7 @@ 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 125865daaf17..8092f4f84ee6 100644
--- a/arch/arm/mach-sti/Kconfig
+++ b/arch/arm/mach-sti/Kconfig
@@ -6,7 +6,6 @@ menuconfig ARCH_STI
 	select PINCTRL
 	select PINCTRL_ST
 	select MFD_SYSCON
-	select ARCH_HAS_RESET_CONTROLLER
 	select HAVE_ARM_SCU if SMP
 	select ARCH_REQUIRE_GPIOLIB
 	select ARM_ERRATA_754322
@@ -14,7 +13,6 @@ 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 STiH41x SOCs like STiH415/416 using the device tree
 	  for discovery
diff --git a/arch/arm/mach-sunxi/Kconfig b/arch/arm/mach-sunxi/Kconfig
index 4efe2d43a126..60b58ca02162 100644
--- a/arch/arm/mach-sunxi/Kconfig
+++ b/arch/arm/mach-sunxi/Kconfig
@@ -1,7 +1,6 @@
 menuconfig ARCH_SUNXI
 	bool "Allwinner SoCs" if ARCH_MULTI_V7
 	select ARCH_REQUIRE_GPIOLIB
-	select ARCH_HAS_RESET_CONTROLLER
 	select CLKSRC_MMIO
 	select GENERIC_IRQ_CHIP
 	select PINCTRL
diff --git a/arch/arm/mach-sunxi/sunxi.c b/arch/arm/mach-sunxi/sunxi.c
index c2be98f38e73..b1c39eed19f1 100644
--- a/arch/arm/mach-sunxi/sunxi.c
+++ b/arch/arm/mach-sunxi/sunxi.c
@@ -45,7 +45,7 @@ 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 0fa4c5f8b1be..269efaaa6843 100644
--- a/arch/arm/mach-tegra/Kconfig
+++ b/arch/arm/mach-tegra/Kconfig
@@ -9,7 +9,6 @@ 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
 	select USB_ULPI if USB_PHY
diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index e6cd1a32025a..b93b75bf0a2d 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 35215f6867d3..cb21e3821244 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_KMS_HELPER
 	select DRM_KMS_FB_HELPER
 	select DRM_PANEL
diff --git a/drivers/gpu/drm/sti/Kconfig b/drivers/gpu/drm/sti/Kconfig
index e3aa5afc0244..8aeb4cdd76e5 100644
--- a/drivers/gpu/drm/sti/Kconfig
+++ b/drivers/gpu/drm/sti/Kconfig
@@ -1,7 +1,6 @@
 config DRM_STI
 	tristate "DRM Support for STMicroelectronics SoC stiH41x Series"
 	depends on DRM && (SOC_STIH415 || SOC_STIH416 || ARCH_MULTIPLATFORM) && HAVE_DMA_ATTRS
-	select RESET_CONTROLLER
 	select DRM_KMS_HELPER
 	select DRM_GEM_CMA_HELPER
 	select DRM_KMS_CMA_HELPER
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 e24c2b680b47..775134dc7fc3 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -886,7 +886,6 @@ 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 7eb5859dd035..53d92382030f 100644
--- a/drivers/phy/Kconfig
+++ b/drivers/phy/Kconfig
@@ -17,7 +17,8 @@ config GENERIC_PHY
 
 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.
@@ -218,7 +219,6 @@ config PHY_MT65XX_USB3
 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
@@ -232,7 +232,6 @@ 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
 	select GENERIC_PHY
 	help
 	  Enable this to support the transceiver that is part of Allwinner
@@ -342,7 +341,6 @@ 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 e68fd951129a..50bd2e37aaeb 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_COMMON
 
 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_COMMON
 
 config PINCTRL_SUN9I_A80
diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
index 0615f50a14cd..12026a1893b5 100644
--- a/drivers/reset/Kconfig
+++ b/drivers/reset/Kconfig
@@ -1,15 +1,24 @@
-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
+
+config RESET_SUNXI
+	bool "Allwinner reset controller" if COMPILE_TEST
+	default ARCH_SUNXI
+	select RESET_CONTROLLER
 
 source "drivers/reset/sti/Kconfig"
+
+endmenu
diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
index 85d5904e5480..e05aeffb692f 100644
--- a/drivers/reset/Makefile
+++ b/drivers/reset/Makefile
@@ -1,8 +1,8 @@
 obj-$(CONFIG_RESET_CONTROLLER) += core.o
 obj-$(CONFIG_ARCH_LPC18XX) += reset-lpc18xx.o
-obj-$(CONFIG_ARCH_SOCFPGA) += reset-socfpga.o
-obj-$(CONFIG_ARCH_BERLIN) += reset-berlin.o
-obj-$(CONFIG_ARCH_SUNXI) += reset-sunxi.o
-obj-$(CONFIG_ARCH_STI) += sti/
+obj-$(CONFIG_RESET_SOCFPGA) += reset-socfpga.o
+obj-$(CONFIG_RESET_BERLIN) += reset-berlin.o
+obj-$(CONFIG_RESET_SUNXI) += reset-sunxi.o
+obj-$(CONFIG_RESET_STI_SYSCFG) += sti/
 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 f8c15a37fb35..ef9bb8675577 100644
--- a/drivers/reset/sti/Kconfig
+++ b/drivers/reset/sti/Kconfig
@@ -1,19 +1,19 @@
-if ARCH_STI
+if ARCH_STI || COMPILE_TEST
 
-config STI_RESET_SYSCFG
+config RESET_STI_SYSCFG
 	bool
 	select RESET_CONTROLLER
 
-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 9d5068248aa0..511c40e08780 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 b046fd94346a..4a62428836f3 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -527,7 +527,6 @@ 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
@@ -548,7 +547,6 @@ 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.
 
@@ -562,7 +560,7 @@ 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
@@ -571,7 +569,6 @@ 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
@@ -580,7 +577,7 @@ 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 c463c89b90ef..2e7524f0f3f7 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -205,7 +205,6 @@ config SPEAR_THERMAL
 config ROCKCHIP_THERMAL
 	tristate "Rockchip thermal driver"
 	depends on ARCH_ROCKCHIP || COMPILE_TEST
-	depends on RESET_CONTROLLER
 	help
 	  Rockchip thermal driver provides support for Temperature sensor
 	  ADC (TS-ADC) found on Rockchip SoCs. It supports one critical
diff --git a/drivers/usb/phy/Kconfig b/drivers/usb/phy/Kconfig
index 173132416170..7acb038fd26a 100644
--- a/drivers/usb/phy/Kconfig
+++ b/drivers/usb/phy/Kconfig
@@ -140,7 +140,6 @@ config USB_ISP1301
 config USB_MSM_OTG
 	tristate "Qualcomm on-chip USB OTG controller support"
 	depends on (USB || USB_GADGET) && (ARCH_QCOM || COMPILE_TEST)
-	depends on RESET_CONTROLLER
 	depends on EXTCON
 	select USB_PHY
 	help
diff --git a/include/linux/reset.h b/include/linux/reset.h
index 7f65f9cff951..56c389347096 100644
--- a/include/linux/reset.h
+++ b/include/linux/reset.h
@@ -40,38 +40,49 @@ struct reset_control *of_reset_control_get(struct device_node *node,
 
 #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 device_reset_optional(struct device *dev)
 {
-	return -ENOSYS;
+	if (of_property_read_bool(dev->of_node, "resets"))
+		return -ENOSYS;
+
+	return 0;
 }
 
 static inline struct reset_control *__must_check reset_control_get(
@@ -88,16 +99,21 @@ static inline struct reset_control *__must_check devm_reset_control_get(
 	return ERR_PTR(-EINVAL);
 }
 
+/*
+ * 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 ERR_PTR(-ENOSYS);
+	return ERR_PTR(device_reset_optional(dev));
 }
 
 static inline struct reset_control *devm_reset_control_get_optional(
 					struct device *dev, const char *id)
 {
-	return ERR_PTR(-ENOSYS);
+	return reset_control_get_optional(dev, id);
 }
 
 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
 	help

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Re: [RFC PATCH 0/7] reset: make RESET_CONTROLLER a select'ed option

[Masahiro Yamada]

Hi Arnd,



2015-11-05 23:49 GMT+09:00 Arnd Bergmann <arnd-r2nGTMty4D4@public.gmane.org>:
> On Thursday 05 November 2015 20:15:21 Masahiro Yamada wrote:
>> When I was implementing a new reset controller for my SoCs,
>> I struggled to make my sub-menu shown under the reset
>> controller menu.
>> I noticed the Kconfig in reset sub-system are screwed up due to two
>> config options (ARCH_HAS_RESET_CONTROLLER and RESET_CONTROLLER).
>>
>> I think only the former should be select'ed by relevant SoCs,
>> but in fact the latter is also select'ed here and there.
>> Mixing "select" to a user-configurable option is a mess.
>>
>> Finally, I started to wonder whether it could be more simpler?
>>
>> The first patch drops ARCH_HAS_RESET_CONTROLLER.
>> RESET_CONTROLLER should be directly selected by SoCs.
>>
>> The rest of this series are minor clean ups in other
>> sub-systems.
>> I can postpone them if changes over cross sub-systems
>> are not preferred.
>
> Thanks a lot for picking up this topic! It has been annoying me
> for a while and I have submitted an experimental patch some time
> ago, but not finished it myself.
>
> For some reason, I only see a subset of your patches here (patch 1, 4 and 6),
> so I don't know exactly what you did.

All the patches CCed linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
so you can dig into LKML log or the following patchwork
https://patchwork.kernel.org/project/LKML/list/




> For reference, you can find
> my original patch below. Please check if I did things that your
> series doesn't do, and whether those are still needed.

Thanks.

Yours looks mostly nice, and this work is worth continuing.
(I am pleased to review it when you submit the next version.)

I have some comments.

[1]
Why is ARCH_HAS_RESET_CONTROLLER select'ed by
ARCH_MULTIPLATFORM, but not by others?
This seems weird.

We do not have such options like
  ARCH_HAS_PINCTRL,  ARCH_HAS_COMMON_CLK...


[2]
The difference is that yours is adding per-driver options such as
RESET_SOCFPGA, RESET_BERLIN, etc.
I think this is a good idea.

But, I notice lowlevel drivers select RESET_CONTROLLER,
for example, RESET_SOCFPGA select RESET_CONTROLLER.

We generally do the opposite in other subsystems, I think.


For example, the whole of clk menu is guarded by "depends on COMMON_CLK".

menu "Common Clock Framework"
         depends on COMMON_CLK

     <bunch of low-level drivers>

endmenu


Likewise for pinctrl.





-- 
Best Regards
Masahiro Yamada

Re: [RFC PATCH 0/7] reset: make RESET_CONTROLLER a select'ed option

[Arnd Bergmann]

On Friday 06 November 2015 14:58:04 Masahiro Yamada wrote:
> 2015-11-05 23:49 GMT+09:00 Arnd Bergmann <arnd@arndb.de>:
> [1]
> Why is ARCH_HAS_RESET_CONTROLLER select'ed by
> ARCH_MULTIPLATFORM, but not by others?
> This seems weird.

I tried to avoid having to set this from each platform separately,
and all users of ARCH_HAS_RESET_CONTROLLER on ARM are also
based on ARCH_MULTIPLATFORM. The other platforms are lagging behind
in their conversion and use neither reset controllers not
multiplatform. If anyone wants to make them use reset controllers,
we probably want them to use multiplatform as well.

> We do not have such options like
>   ARCH_HAS_PINCTRL,  ARCH_HAS_COMMON_CLK...

We could of course change it in one direction or another, but it
didn't seem urgent here.

> [2]
> The difference is that yours is adding per-driver options such as
> RESET_SOCFPGA, RESET_BERLIN, etc.
> I think this is a good idea.
> 
> But, I notice lowlevel drivers select RESET_CONTROLLER,
> for example, RESET_SOCFPGA select RESET_CONTROLLER.
> 
> We generally do the opposite in other subsystems, I think.
> 
> 
> For example, the whole of clk menu is guarded by "depends on COMMON_CLK".
> 
> menu "Common Clock Framework"
>          depends on COMMON_CLK
> 
>      <bunch of low-level drivers>
> 
> endmenu
> 
> 
> Likewise for pinctrl.

We can do that too, either way works for me, and we are using both
in other parts of the kernel. REGMAP is an example for another subsystem
that gets selected by each driver that relies on the framework.

The practical difference is only in the case that the subsystem
is enabled (e.g. by using ARCH_MULTIPLATFORM) but all reset drivers
are disabled. A device driver using the API in one case will see
the stubbed-out inline helpers and not contain any object code
that relies on non-NULL return values from them, while in the
other case it calls into the subsystem code to get the same
return value at runtime.

If you volunteer to clean up my patch, feel free to choose between
the two options as you like.

	Arnd