Re: [PATCH 7/8] gpiolib: split of_mm_gpio_chip out of linux/of_gpio.h

From: Andy Shevchenko
Date: Thu Jan 26 2023 - 09:08:46 EST


On Thu, Jan 26, 2023 at 02:28:00PM +0100, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@xxxxxxxx>
>
> This is a rarely used feature that has nothing to do with the
> client-side of_gpio.h.
>
> Split it out with a separate header file and Kconfig option
> so it can be removed on its own timeline aside from removing
> the of_gpio consumer interfaces.

One nit-pick below, otherwise
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>

> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---
> arch/powerpc/platforms/44x/Kconfig | 1 +
> arch/powerpc/platforms/4xx/gpio.c | 2 +-
> arch/powerpc/platforms/8xx/Kconfig | 1 +
> arch/powerpc/platforms/8xx/cpm1.c | 2 +-
> arch/powerpc/platforms/Kconfig | 2 ++
> arch/powerpc/sysdev/cpm_common.c | 2 +-
> drivers/gpio/Kconfig | 11 +++++++
> drivers/gpio/TODO | 15 ++++++---
> drivers/gpio/gpio-altera.c | 2 +-
> drivers/gpio/gpio-mm-lantiq.c | 2 +-
> drivers/gpio/gpio-mpc5200.c | 2 +-
> drivers/gpio/gpiolib-of.c | 3 ++
> drivers/soc/fsl/qe/gpio.c | 2 +-
> include/linux/gpio/legacy-of-mm-gpiochip.h | 36 ++++++++++++++++++++++
> include/linux/of_gpio.h | 21 -------------
> 15 files changed, 71 insertions(+), 33 deletions(-)
> create mode 100644 include/linux/gpio/legacy-of-mm-gpiochip.h
>
> diff --git a/arch/powerpc/platforms/44x/Kconfig b/arch/powerpc/platforms/44x/Kconfig
> index 25b80cd558f8..1624ebf95497 100644
> --- a/arch/powerpc/platforms/44x/Kconfig
> +++ b/arch/powerpc/platforms/44x/Kconfig
> @@ -230,6 +230,7 @@ config PPC4xx_GPIO
> bool "PPC4xx GPIO support"
> depends on 44x
> select GPIOLIB
> + select OF_GPIO_MM_GPIOCHIP
> help
> Enable gpiolib support for ppc440 based boards
>
> diff --git a/arch/powerpc/platforms/4xx/gpio.c b/arch/powerpc/platforms/4xx/gpio.c
> index 49ee8d365852..e5f2319e5cbe 100644
> --- a/arch/powerpc/platforms/4xx/gpio.c
> +++ b/arch/powerpc/platforms/4xx/gpio.c
> @@ -14,7 +14,7 @@
> #include <linux/spinlock.h>
> #include <linux/io.h>
> #include <linux/of.h>
> -#include <linux/of_gpio.h>
> +#include <linux/gpio/legacy-of-mm-gpiochip.h>
> #include <linux/gpio/driver.h>
> #include <linux/types.h>
> #include <linux/slab.h>
> diff --git a/arch/powerpc/platforms/8xx/Kconfig b/arch/powerpc/platforms/8xx/Kconfig
> index 60cc5b537a98..a14d9d8997a4 100644
> --- a/arch/powerpc/platforms/8xx/Kconfig
> +++ b/arch/powerpc/platforms/8xx/Kconfig
> @@ -101,6 +101,7 @@ comment "Generic MPC8xx Options"
> config 8xx_GPIO
> bool "GPIO API Support"
> select GPIOLIB
> + select OF_GPIO_MM_GPIOCHIP
> help
> Saying Y here will cause the ports on an MPC8xx processor to be used
> with the GPIO API. If you say N here, the kernel needs less memory.
> diff --git a/arch/powerpc/platforms/8xx/cpm1.c b/arch/powerpc/platforms/8xx/cpm1.c
> index bb38c8d8f8de..56ca14f77543 100644
> --- a/arch/powerpc/platforms/8xx/cpm1.c
> +++ b/arch/powerpc/platforms/8xx/cpm1.c
> @@ -44,7 +44,7 @@
> #include <asm/fs_pd.h>
>
> #ifdef CONFIG_8xx_GPIO
> -#include <linux/of_gpio.h>
> +#include <linux/gpio/legacy-of-mm-gpiochip.h>
> #endif
>
> #define CPM_MAP_SIZE (0x4000)
> diff --git a/arch/powerpc/platforms/Kconfig b/arch/powerpc/platforms/Kconfig
> index d41dad227de8..8e4bbd19dec5 100644
> --- a/arch/powerpc/platforms/Kconfig
> +++ b/arch/powerpc/platforms/Kconfig
> @@ -244,6 +244,7 @@ config QE_GPIO
> bool "QE GPIO support"
> depends on QUICC_ENGINE
> select GPIOLIB
> + select OF_GPIO_MM_GPIOCHIP
> help
> Say Y here if you're going to use hardware that connects to the
> QE GPIOs.
> @@ -254,6 +255,7 @@ config CPM2
> select CPM
> select HAVE_PCI
> select GPIOLIB
> + select OF_GPIO_MM_GPIOCHIP
> help
> The CPM2 (Communications Processor Module) is a coprocessor on
> embedded CPUs made by Freescale. Selecting this option means that
> diff --git a/arch/powerpc/sysdev/cpm_common.c b/arch/powerpc/sysdev/cpm_common.c
> index 7dc1960f8bdb..8234013a8772 100644
> --- a/arch/powerpc/sysdev/cpm_common.c
> +++ b/arch/powerpc/sysdev/cpm_common.c
> @@ -31,7 +31,7 @@
> #include <mm/mmu_decl.h>
>
> #if defined(CONFIG_CPM2) || defined(CONFIG_8xx_GPIO)
> -#include <linux/of_gpio.h>
> +#include <linux/gpio/legacy-of-mm-gpiochip.h>
> #endif
>
> static int __init cpm_init(void)
> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> index 06a268d56800..7534a2115d18 100644
> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -39,6 +39,14 @@ config GPIOLIB_IRQCHIP
> select IRQ_DOMAIN
> bool
>
> +config OF_GPIO_MM_GPIOCHIP
> + bool
> + help
> + This adds support for the legacy 'struct of_mm_gpio_chip' interface
> + from PowerPC. Existing drivers using this interface need to select
> + this symbol, but new drivers should use the generic gpio-mmio

gpio-regmap

I would even not mention gpio-mmio.

> + infrastructure instead.
> +
> config DEBUG_GPIO
> bool "Debug GPIO calls"
> depends on DEBUG_KERNEL
> @@ -131,6 +139,7 @@ config GPIO_ALTERA
> tristate "Altera GPIO"
> depends on OF_GPIO
> select GPIOLIB_IRQCHIP
> + select OF_GPIO_MM_GPIOCHIP
> help
> Say Y or M here to build support for the Altera PIO device.
>
> @@ -403,6 +412,7 @@ config GPIO_MENZ127
> config GPIO_MM_LANTIQ
> bool "Lantiq Memory mapped GPIOs"
> depends on LANTIQ && SOC_XWAY
> + select OF_GPIO_MM_GPIOCHIP
> help
> This enables support for memory mapped GPIOs on the External Bus Unit
> (EBU) found on Lantiq SoCs. The GPIOs are output only as they are
> @@ -411,6 +421,7 @@ config GPIO_MM_LANTIQ
> config GPIO_MPC5200
> def_bool y
> depends on PPC_MPC52xx
> + select OF_GPIO_MM_GPIOCHIP
>
> config GPIO_MPC8XXX
> bool "MPC512x/MPC8xxx/QorIQ GPIO support"
> diff --git a/drivers/gpio/TODO b/drivers/gpio/TODO
> index 68ada1066941..189c3abe7e79 100644
> --- a/drivers/gpio/TODO
> +++ b/drivers/gpio/TODO
> @@ -59,11 +59,6 @@ the device tree back-end. It is legacy and should not be used in new code.
>
> Work items:
>
> -- Get rid of struct of_mm_gpio_chip altogether: use the generic MMIO
> - GPIO for all current users (see below). Delete struct of_mm_gpio_chip,
> - to_of_mm_gpio_chip(), of_mm_gpiochip_add_data(), of_mm_gpiochip_remove()
> - from the kernel.
> -
> - Change all consumer drivers that #include <linux/of_gpio.h> to
> #include <linux/gpio/consumer.h> and stop doing custom parsing of the
> GPIO lines from the device tree. This can be tricky and often ivolves
> @@ -81,6 +76,16 @@ Work items:
> uses <linux/gpio/consumer.h> or <linux/gpio/driver.h> instead.
>
>
> +Get rid of <linux/gpio/legacy-of-mm-gpiochip.h>
> +
> +Work items:
> +
> +- Get rid of struct of_mm_gpio_chip altogether: use the generic MMIO
> + GPIO for all current users (see below). Delete struct of_mm_gpio_chip,
> + to_of_mm_gpio_chip(), of_mm_gpiochip_add_data(), of_mm_gpiochip_remove(),
> + CONFIG_OF_GPIO_MM_GPIOCHIP from the kernel.
> +
> +
> Get rid of <linux/gpio.h>
>
> This legacy header is a one stop shop for anything GPIO is closely tied
> diff --git a/drivers/gpio/gpio-altera.c b/drivers/gpio/gpio-altera.c
> index b59fae993626..99e137f8097e 100644
> --- a/drivers/gpio/gpio-altera.c
> +++ b/drivers/gpio/gpio-altera.c
> @@ -7,7 +7,7 @@
> #include <linux/io.h>
> #include <linux/module.h>
> #include <linux/gpio/driver.h>
> -#include <linux/of_gpio.h> /* For of_mm_gpio_chip */
> +#include <linux/gpio/legacy-of-mm-gpiochip.h>
> #include <linux/platform_device.h>
>
> #define ALTERA_GPIO_MAX_NGPIO 32
> diff --git a/drivers/gpio/gpio-mm-lantiq.c b/drivers/gpio/gpio-mm-lantiq.c
> index 538e31fe8903..27ff84c5d162 100644
> --- a/drivers/gpio/gpio-mm-lantiq.c
> +++ b/drivers/gpio/gpio-mm-lantiq.c
> @@ -10,8 +10,8 @@
> #include <linux/platform_device.h>
> #include <linux/mutex.h>
> #include <linux/gpio/driver.h>
> +#include <linux/gpio/legacy-of-mm-gpiochip.h.h>
> #include <linux/of.h>
> -#include <linux/of_gpio.h>
> #include <linux/io.h>
> #include <linux/slab.h>
>
> diff --git a/drivers/gpio/gpio-mpc5200.c b/drivers/gpio/gpio-mpc5200.c
> index 000494e0c533..3b0bfff8c778 100644
> --- a/drivers/gpio/gpio-mpc5200.c
> +++ b/drivers/gpio/gpio-mpc5200.c
> @@ -8,7 +8,7 @@
> #include <linux/of.h>
> #include <linux/kernel.h>
> #include <linux/slab.h>
> -#include <linux/of_gpio.h>
> +#include <linux/gpio/legacy-of-mm-gpiochip.h>
> #include <linux/io.h>
> #include <linux/of_platform.h>
> #include <linux/module.h>
> diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
> index edc769d2d338..6a08569a20c1 100644
> --- a/drivers/gpio/gpiolib-of.c
> +++ b/drivers/gpio/gpiolib-of.c
> @@ -877,6 +877,8 @@ static int of_gpio_simple_xlate(struct gpio_chip *gc,
> return gpiospec->args[0];
> }
>
> +#if IS_ENABLED(CONFIG_OF_GPIO_MM_GPIOCHIP)
> +#include <linux/gpio/legacy-of-mm-gpiochip.h>
> /**
> * of_mm_gpiochip_add_data - Add memory mapped GPIO chip (bank)
> * @np: device node of the GPIO chip
> @@ -949,6 +951,7 @@ void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc)
> kfree(gc->label);
> }
> EXPORT_SYMBOL_GPL(of_mm_gpiochip_remove);
> +#endif
>
> #ifdef CONFIG_PINCTRL
> static int of_gpiochip_add_pin_range(struct gpio_chip *chip)
> diff --git a/drivers/soc/fsl/qe/gpio.c b/drivers/soc/fsl/qe/gpio.c
> index 1c41eb49d5a7..3ef24ba0245b 100644
> --- a/drivers/soc/fsl/qe/gpio.c
> +++ b/drivers/soc/fsl/qe/gpio.c
> @@ -13,7 +13,7 @@
> #include <linux/err.h>
> #include <linux/io.h>
> #include <linux/of.h>
> -#include <linux/of_gpio.h> /* for of_mm_gpio_chip */
> +#include <linux/gpio/legacy-of-mm-gpiochip.h>
> #include <linux/gpio/consumer.h>
> #include <linux/gpio/driver.h>
> #include <linux/slab.h>
> diff --git a/include/linux/gpio/legacy-of-mm-gpiochip.h b/include/linux/gpio/legacy-of-mm-gpiochip.h
> new file mode 100644
> index 000000000000..2e2bd3b19cc3
> --- /dev/null
> +++ b/include/linux/gpio/legacy-of-mm-gpiochip.h
> @@ -0,0 +1,36 @@
> +/* SPDX-License-Identifier: GPL-2.0+ */
> +/*
> + * OF helpers for the old of_mm_gpio_chip, used on ppc32 and nios2,
> + * do not use in new code.
> + *
> + * Copyright (c) 2007-2008 MontaVista Software, Inc.
> + *
> + * Author: Anton Vorontsov <avorontsov@xxxxxxxxxxxxx>
> + */
> +
> +#ifndef __LINUX_GPIO_LEGACY_OF_MM_GPIO_CHIP_H
> +#define __LINUX_GPIO_LEGACY_OF_MM_GPIO_CHIP_H
> +
> +#include <linux/gpio/driver.h>
> +#include <linux/of.h>
> +
> +/*
> + * OF GPIO chip for memory mapped banks
> + */
> +struct of_mm_gpio_chip {
> + struct gpio_chip gc;
> + void (*save_regs)(struct of_mm_gpio_chip *mm_gc);
> + void __iomem *regs;
> +};
> +
> +static inline struct of_mm_gpio_chip *to_of_mm_gpio_chip(struct gpio_chip *gc)
> +{
> + return container_of(gc, struct of_mm_gpio_chip, gc);
> +}
> +
> +extern int of_mm_gpiochip_add_data(struct device_node *np,
> + struct of_mm_gpio_chip *mm_gc,
> + void *data);
> +extern void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc);
> +
> +#endif /* __LINUX_GPIO_LEGACY_OF_MM_GPIO_CHIP_H */
> diff --git a/include/linux/of_gpio.h b/include/linux/of_gpio.h
> index 935225caf70d..04e1f76acdd7 100644
> --- a/include/linux/of_gpio.h
> +++ b/include/linux/of_gpio.h
> @@ -34,30 +34,9 @@ enum of_gpio_flags {
>
> #ifdef CONFIG_OF_GPIO
>
> -#include <linux/container_of.h>
> -
> -/*
> - * OF GPIO chip for memory mapped banks
> - */
> -struct of_mm_gpio_chip {
> - struct gpio_chip gc;
> - void (*save_regs)(struct of_mm_gpio_chip *mm_gc);
> - void __iomem *regs;
> -};
> -
> -static inline struct of_mm_gpio_chip *to_of_mm_gpio_chip(struct gpio_chip *gc)
> -{
> - return container_of(gc, struct of_mm_gpio_chip, gc);
> -}
> -
> extern int of_get_named_gpio(const struct device_node *np,
> const char *list_name, int index);
>
> -extern int of_mm_gpiochip_add_data(struct device_node *np,
> - struct of_mm_gpio_chip *mm_gc,
> - void *data);
> -extern void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc);
> -
> #else /* CONFIG_OF_GPIO */
>
> #include <linux/errno.h>
> --
> 2.39.0
>

--
With Best Regards,
Andy Shevchenko