MIPS: Alchemy: Rewrite GPIO support.

The current in-kernel Alchemy GPIO support is far too inflexible for
all my use cases.  To address this, the following changes are made:

* create generic functions which deal with manipulating the on-chip
  GPIO1/2 blocks.  Such functions are universally useful.
* Macros for GPIO2 shared interrupt management and block control.
* support for both built-in CONFIG_GPIOLIB and fast, inlined GPIO macros.

  If CONFIG_GPIOLIB is not enabled, provide linux gpio framework
  compatibility by directly inlining the GPIO1/2 functions.  GPIO access
  is limited to on-chip ones and they can be accessed as documented in
  the datasheets (GPIO0-31 and 200-215).

  If CONFIG_GPIOLIB is selected, two (2) gpio_chip-s, one for GPIO1 and
  one for GPIO2, are registered.  GPIOs can still be accessed by using
  the numberspace established in the databooks.

  However this is not yet flexible enough for my uses:  My Alchemy
  systems have a documented "external" gpio interface (fixed, different
  numberspace) and can support a variety of baseboards, some of which
  are equipped with I2C gpio expanders.  I want to be able to provide
  the default 16 GPIOs of the CPU board numbered as 0..15 and also
  support gpio expanders, if present, starting as gpio16.

  To achieve this, a new Kconfig symbol for Alchemy is introduced,
  CONFIG_ALCHEMY_GPIO_INDIRECT, which boards can enable to signal
  that they don't want the Alchemy numberspace exposed to the outside
  world, but instead want to provide their own.  Boards are now respon-
  sible for providing the linux gpio interface glue code (either in a
  custom gpio.h header (in board include directory) or with gpio_chips).

  To make the board-specific inlined gpio functions work, the MIPS
  Makefile must be changed so that the mach-au1x00/gpio.h header is
  included _after_ the board headers, by moving the inclusion of
  the mach-au1x00/ to the end of the header list.

  See arch/mips/include/asm/mach-au1x00/gpio.h for more info.

Signed-off-by: Manuel Lauss <manuel.lauss@gmail.com>
Acked-by: Florian Fainelli <florian@openwrt.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

4 files changed, 156 insertions, 203 deletions

diff --git a/arch/mips/alchemy/Kconfig b/arch/mips/alchemy/Kconfig
index 8128aeb..00b498e 100644
--- a/arch/mips/alchemy/Kconfig
+++ b/arch/mips/alchemy/Kconfig
@@ -1,3 +1,14 @@
+# au1000-style gpio
+config ALCHEMY_GPIO_AU1000
+	bool
+
+# select this in your board config if you don't want to use the gpio
+# namespace as documented in the manuals.  In this case however you need
+# to create the necessary gpio_* functions in your board code/headers!
+# see arch/mips/include/asm/mach-au1x00/gpio.h   for more information.
+config ALCHEMY_GPIO_INDIRECT
+	def_bool n
+
 choice
 	prompt "Machine type"
 	depends on MACH_ALCHEMY
@@ -108,22 +119,27 @@ endchoice
 config SOC_AU1000
 	bool
 	select SOC_AU1X00
+	select ALCHEMY_GPIO_AU1000
 
 config SOC_AU1100
 	bool
 	select SOC_AU1X00
+	select ALCHEMY_GPIO_AU1000
 
 config SOC_AU1500
 	bool
 	select SOC_AU1X00
+	select ALCHEMY_GPIO_AU1000
 
 config SOC_AU1550
 	bool
 	select SOC_AU1X00
+	select ALCHEMY_GPIO_AU1000
 
 config SOC_AU1200
 	bool
 	select SOC_AU1X00
+	select ALCHEMY_GPIO_AU1000
 
 config SOC_AU1X00
 	bool
@@ -134,4 +150,5 @@ config SOC_AU1X00
 	select SYS_HAS_CPU_MIPS32_R1
 	select SYS_SUPPORTS_32BIT_KERNEL
 	select SYS_SUPPORTS_APM_EMULATION
-	select ARCH_REQUIRE_GPIOLIB
+	select GENERIC_GPIO
+	select ARCH_WANT_OPTIONAL_GPIOLIB
diff --git a/arch/mips/alchemy/common/Makefile b/arch/mips/alchemy/common/Makefile
index d50d476..b67fb51 100644
--- a/arch/mips/alchemy/common/Makefile
+++ b/arch/mips/alchemy/common/Makefile
@@ -7,7 +7,14 @@
 
 obj-y += prom.o irq.o puts.o time.o reset.o \
 	clocks.o platform.o power.o setup.o \
-	sleeper.o dma.o dbdma.o gpio.o
+	sleeper.o dma.o dbdma.o
+
+# optional gpiolib support
+ifeq ($(CONFIG_ALCHEMY_GPIO_INDIRECT),)
+ ifeq ($(CONFIG_GPIOLIB),y)
+  obj-$(CONFIG_ALCHEMY_GPIO_AU1000) += gpiolib-au1000.o
+ endif
+endif
 
 obj-$(CONFIG_PCI)		+= pci.o
 
diff --git a/arch/mips/alchemy/common/gpio.c b/arch/mips/alchemy/common/gpio.c
deleted file mode 100644
index 91a9c44..0000000
--- a/arch/mips/alchemy/common/gpio.c
+++ /dev/null
@@ -1,201 +0,0 @@
-/*
- *  Copyright (C) 2007-2009, OpenWrt.org, Florian Fainelli <florian@openwrt.org>
- *  	Architecture specific GPIO support
- *
- *  This program is free software; you can redistribute	 it and/or modify it
- *  under  the terms of	 the GNU General  Public License as published by the
- *  Free Software Foundation;  either version 2 of the	License, or (at your
- *  option) any later version.
- *
- *  THIS  SOFTWARE  IS PROVIDED	  ``AS	IS'' AND   ANY	EXPRESS OR IMPLIED
- *  WARRANTIES,	  INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
- *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
- *  NO	EVENT  SHALL   THE AUTHOR  BE	 LIABLE FOR ANY	  DIRECT, INDIRECT,
- *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
- *  NOT LIMITED	  TO, PROCUREMENT OF  SUBSTITUTE GOODS	OR SERVICES; LOSS OF
- *  USE, DATA,	OR PROFITS; OR	BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
- *  ANY THEORY OF LIABILITY, WHETHER IN	 CONTRACT, STRICT LIABILITY, OR TORT
- *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
- *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- *  You should have received a copy of the  GNU General Public License along
- *  with this program; if not, write  to the Free Software Foundation, Inc.,
- *  675 Mass Ave, Cambridge, MA 02139, USA.
- *
- *  Notes :
- * 	au1000 SoC have only one GPIO line : GPIO1
- * 	others have a second one : GPIO2
- */
-
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/types.h>
-#include <linux/platform_device.h>
-#include <linux/gpio.h>
-
-#include <asm/mach-au1x00/au1000.h>
-#include <asm/gpio.h>
-
-struct au1000_gpio_chip {
-	struct gpio_chip	chip;
-	void __iomem		*regbase;
-};
-
-#if !defined(CONFIG_SOC_AU1000)
-static int au1000_gpio2_get(struct gpio_chip *chip, unsigned offset)
-{
-	u32 mask = 1 << offset;
-	struct au1000_gpio_chip *gpch;
-
-	gpch = container_of(chip, struct au1000_gpio_chip, chip);
-	return readl(gpch->regbase + AU1000_GPIO2_ST) & mask;
-}
-
-static void au1000_gpio2_set(struct gpio_chip *chip,
-				unsigned offset, int value)
-{
-	u32 mask = ((GPIO2_OUT_EN_MASK << offset) | (!!value << offset));
-	struct au1000_gpio_chip *gpch;
-	unsigned long flags;
-
-	gpch = container_of(chip, struct au1000_gpio_chip, chip);
-
-	local_irq_save(flags);
-	writel(mask, gpch->regbase + AU1000_GPIO2_OUT);
-	local_irq_restore(flags);
-}
-
-static int au1000_gpio2_direction_input(struct gpio_chip *chip, unsigned offset)
-{
-	u32 mask = 1 << offset;
-	u32 tmp;
-	struct au1000_gpio_chip *gpch;
-	unsigned long flags;
-
-	gpch = container_of(chip, struct au1000_gpio_chip, chip);
-
-	local_irq_save(flags);
-	tmp = readl(gpch->regbase + AU1000_GPIO2_DIR);
-	tmp &= ~mask;
-	writel(tmp, gpch->regbase + AU1000_GPIO2_DIR);
-	local_irq_restore(flags);
-
-	return 0;
-}
-
-static int au1000_gpio2_direction_output(struct gpio_chip *chip,
-					unsigned offset, int value)
-{
-	u32 mask = 1 << offset;
-	u32 out_mask = ((GPIO2_OUT_EN_MASK << offset) | (!!value << offset));
-	u32 tmp;
-	struct au1000_gpio_chip *gpch;
-	unsigned long flags;
-
-	gpch = container_of(chip, struct au1000_gpio_chip, chip);
-
-	local_irq_save(flags);
-	tmp = readl(gpch->regbase + AU1000_GPIO2_DIR);
-	tmp |= mask;
-	writel(tmp, gpch->regbase + AU1000_GPIO2_DIR);
-	writel(out_mask, gpch->regbase + AU1000_GPIO2_OUT);
-	local_irq_restore(flags);
-
-	return 0;
-}
-#endif /* !defined(CONFIG_SOC_AU1000) */
-
-static int au1000_gpio1_get(struct gpio_chip *chip, unsigned offset)
-{
-	u32 mask = 1 << offset;
-	struct au1000_gpio_chip *gpch;
-
-	gpch = container_of(chip, struct au1000_gpio_chip, chip);
-	return readl(gpch->regbase + AU1000_GPIO1_ST) & mask;
-}
-
-static void au1000_gpio1_set(struct gpio_chip *chip,
-				unsigned offset, int value)
-{
-	u32 mask = 1 << offset;
-	u32 reg_offset;
-	struct au1000_gpio_chip *gpch;
-	unsigned long flags;
-
-	gpch = container_of(chip, struct au1000_gpio_chip, chip);
-
-	if (value)
-		reg_offset = AU1000_GPIO1_OUT;
-	else
-		reg_offset = AU1000_GPIO1_CLR;
-
-	local_irq_save(flags);
-	writel(mask, gpch->regbase + reg_offset);
-	local_irq_restore(flags);
-}
-
-static int au1000_gpio1_direction_input(struct gpio_chip *chip, unsigned offset)
-{
-	u32 mask = 1 << offset;
-	struct au1000_gpio_chip *gpch;
-
-	gpch = container_of(chip, struct au1000_gpio_chip, chip);
-	writel(mask, gpch->regbase + AU1000_GPIO1_ST);
-
-	return 0;
-}
-
-static int au1000_gpio1_direction_output(struct gpio_chip *chip,
-					unsigned offset, int value)
-{
-	u32 mask = 1 << offset;
-	struct au1000_gpio_chip *gpch;
-
-	gpch = container_of(chip, struct au1000_gpio_chip, chip);
-
-	writel(mask, gpch->regbase + AU1000_GPIO1_TRI_OUT);
-	au1000_gpio1_set(chip, offset, value);
-
-	return 0;
-}
-
-struct au1000_gpio_chip au1000_gpio_chip[] = {
-	[0] = {
-		.regbase			= (void __iomem *)SYS_BASE,
-		.chip = {
-			.label			= "au1000-gpio1",
-			.direction_input	= au1000_gpio1_direction_input,
-			.direction_output	= au1000_gpio1_direction_output,
-			.get			= au1000_gpio1_get,
-			.set			= au1000_gpio1_set,
-			.base			= 0,
-			.ngpio			= 32,
-		},
-	},
-#if !defined(CONFIG_SOC_AU1000)
-	[1] = {
-		.regbase                        = (void __iomem *)GPIO2_BASE,
-		.chip = {
-			.label                  = "au1000-gpio2",
-			.direction_input        = au1000_gpio2_direction_input,
-			.direction_output       = au1000_gpio2_direction_output,
-			.get                    = au1000_gpio2_get,
-			.set                    = au1000_gpio2_set,
-			.base                   = AU1XXX_GPIO_BASE,
-			.ngpio                  = 32,
-		},
-	},
-#endif
-};
-
-static int __init au1000_gpio_init(void)
-{
-	gpiochip_add(&au1000_gpio_chip[0].chip);
-#if !defined(CONFIG_SOC_AU1000)
-	gpiochip_add(&au1000_gpio_chip[1].chip);
-#endif
-
-	return 0;
-}
-arch_initcall(au1000_gpio_init);
-
diff --git a/arch/mips/alchemy/common/gpiolib-au1000.c b/arch/mips/alchemy/common/gpiolib-au1000.c
new file mode 100644
index 0000000..1bfa91f
--- /dev/null
+++ b/arch/mips/alchemy/common/gpiolib-au1000.c
@@ -0,0 +1,130 @@
+/*
+ *  Copyright (C) 2007-2009, OpenWrt.org, Florian Fainelli <florian@openwrt.org>
+ *  	GPIOLIB support for Au1000, Au1500, Au1100, Au1550 and Au12x0.
+ *
+ *  This program is free software; you can redistribute	 it and/or modify it
+ *  under  the terms of	 the GNU General  Public License as published by the
+ *  Free Software Foundation;  either version 2 of the	License, or (at your
+ *  option) any later version.
+ *
+ *  THIS  SOFTWARE  IS PROVIDED	  ``AS	IS'' AND   ANY	EXPRESS OR IMPLIED
+ *  WARRANTIES,	  INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
+ *  NO	EVENT  SHALL   THE AUTHOR  BE	 LIABLE FOR ANY	  DIRECT, INDIRECT,
+ *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ *  NOT LIMITED	  TO, PROCUREMENT OF  SUBSTITUTE GOODS	OR SERVICES; LOSS OF
+ *  USE, DATA,	OR PROFITS; OR	BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ *  ANY THEORY OF LIABILITY, WHETHER IN	 CONTRACT, STRICT LIABILITY, OR TORT
+ *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ *  You should have received a copy of the  GNU General Public License along
+ *  with this program; if not, write  to the Free Software Foundation, Inc.,
+ *  675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ *  Notes :
+ * 	au1000 SoC have only one GPIO block : GPIO1
+ * 	Au1100, Au15x0, Au12x0 have a second one : GPIO2
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/platform_device.h>
+#include <linux/gpio.h>
+
+#include <asm/mach-au1x00/au1000.h>
+#include <asm/mach-au1x00/gpio.h>
+
+#if !defined(CONFIG_SOC_AU1000)
+static int gpio2_get(struct gpio_chip *chip, unsigned offset)
+{
+	return alchemy_gpio2_get_value(offset + ALCHEMY_GPIO2_BASE);
+}
+
+static void gpio2_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+	alchemy_gpio2_set_value(offset + ALCHEMY_GPIO2_BASE, value);
+}
+
+static int gpio2_direction_input(struct gpio_chip *chip, unsigned offset)
+{
+	return alchemy_gpio2_direction_input(offset + ALCHEMY_GPIO2_BASE);
+}
+
+static int gpio2_direction_output(struct gpio_chip *chip, unsigned offset,
+				  int value)
+{
+	return alchemy_gpio2_direction_output(offset + ALCHEMY_GPIO2_BASE,
+						value);
+}
+
+static int gpio2_to_irq(struct gpio_chip *chip, unsigned offset)
+{
+	return alchemy_gpio2_to_irq(offset + ALCHEMY_GPIO2_BASE);
+}
+#endif /* !defined(CONFIG_SOC_AU1000) */
+
+static int gpio1_get(struct gpio_chip *chip, unsigned offset)
+{
+	return alchemy_gpio1_get_value(offset + ALCHEMY_GPIO1_BASE);
+}
+
+static void gpio1_set(struct gpio_chip *chip,
+				unsigned offset, int value)
+{
+	alchemy_gpio1_set_value(offset + ALCHEMY_GPIO1_BASE, value);
+}
+
+static int gpio1_direction_input(struct gpio_chip *chip, unsigned offset)
+{
+	return alchemy_gpio1_direction_input(offset + ALCHEMY_GPIO1_BASE);
+}
+
+static int gpio1_direction_output(struct gpio_chip *chip,
+					unsigned offset, int value)
+{
+	return alchemy_gpio1_direction_output(offset + ALCHEMY_GPIO1_BASE,
+					     value);
+}
+
+static int gpio1_to_irq(struct gpio_chip *chip, unsigned offset)
+{
+	return alchemy_gpio1_to_irq(offset + ALCHEMY_GPIO1_BASE);
+}
+
+struct gpio_chip alchemy_gpio_chip[] = {
+	[0] = {
+		.label			= "alchemy-gpio1",
+		.direction_input	= gpio1_direction_input,
+		.direction_output	= gpio1_direction_output,
+		.get			= gpio1_get,
+		.set			= gpio1_set,
+		.to_irq			= gpio1_to_irq,
+		.base			= ALCHEMY_GPIO1_BASE,
+		.ngpio			= ALCHEMY_GPIO1_NUM,
+	},
+#if !defined(CONFIG_SOC_AU1000)
+	[1] = {
+		.label                  = "alchemy-gpio2",
+		.direction_input        = gpio2_direction_input,
+		.direction_output       = gpio2_direction_output,
+		.get                    = gpio2_get,
+		.set                    = gpio2_set,
+		.to_irq			= gpio2_to_irq,
+		.base                   = ALCHEMY_GPIO2_BASE,
+		.ngpio                  = ALCHEMY_GPIO2_NUM,
+	},
+#endif
+};
+
+static int __init alchemy_gpiolib_init(void)
+{
+	gpiochip_add(&alchemy_gpio_chip[0]);
+#if !defined(CONFIG_SOC_AU1000)
+	gpiochip_add(&alchemy_gpio_chip[1]);
+#endif
+
+	return 0;
+}
+arch_initcall(alchemy_gpiolib_init);