gpiolib: split of_mm_gpio_chip out of linux/of_gpio.h

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.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

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
 

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>

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.

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)

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

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)

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-regmap
+	  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"

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

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

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>
 

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>

drivers/gpio/gpiolib-of.c

@@ -892,6 +892,8 @@ 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
@@ -964,6 +966,7 @@ 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)

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>

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@ru.mvista.com>
+ */
+
+#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 */

include/linux/of_gpio.h

@@ -19,30 +19,9 @@ struct device_node;
 
 #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>