powerpc: gpio driver for mpc8349/8572/8610 and compatible

Structured similar to the existing QE GPIO support.

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
Acked-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

3 files changed, 181 insertions, 0 deletions

diff --git a/arch/powerpc/sysdev/Kconfig b/arch/powerpc/sysdev/Kconfig
index 396582835cb5..d0e7bb05c3a4 100644
--- a/arch/powerpc/sysdev/Kconfig
+++ b/arch/powerpc/sysdev/Kconfig
@@ -7,6 +7,15 @@ config PPC4xx_PCI_EXPRESS
         depends on PCI && 4xx
         default n
 
+config MPC8xxx_GPIO
+        bool "MPC8xxx GPIO support"
+        depends on PPC_MPC831x || PPC_MPC834x || PPC_MPC837x || PPC_85xx || PPC_86xx
+        select GENERIC_GPIO
+        select ARCH_REQUIRE_GPIOLIB
+        help
+          Say Y here if you're going to use hardware that connects to the
+          MPC831x/834x/837x/8572/8610 GPIOs.
+
 config PPC_MSI_BITMAP
         bool
         depends on PCI_MSI
diff --git a/arch/powerpc/sysdev/Makefile b/arch/powerpc/sysdev/Makefile
index b6c269eb2650..55618ba9eff0 100644
--- a/arch/powerpc/sysdev/Makefile
+++ b/arch/powerpc/sysdev/Makefile
@@ -16,6 +16,7 @@ obj-$(CONFIG_FSL_SOC)		+= fsl_soc.o
 obj-$(CONFIG_FSL_PCI)           += fsl_pci.o $(fsl-msi-obj-y)
 obj-$(CONFIG_FSL_LBC)           += fsl_lbc.o
 obj-$(CONFIG_FSL_GTM)           += fsl_gtm.o
+obj-$(CONFIG_MPC8xxx_GPIO)      += mpc8xxx_gpio.o
 obj-$(CONFIG_RAPIDIO)           += fsl_rio.o
 obj-$(CONFIG_TSI108_BRIDGE)     += tsi108_pci.o tsi108_dev.o
 obj-$(CONFIG_QUICC_ENGINE)      += qe_lib/
diff --git a/arch/powerpc/sysdev/mpc8xxx_gpio.c b/arch/powerpc/sysdev/mpc8xxx_gpio.c
new file mode 100644
index 000000000000..103eace36194
--- /dev/null
+++ b/arch/powerpc/sysdev/mpc8xxx_gpio.c
@@ -0,0 +1,171 @@
+/*
+ * GPIOs on MPC8349/8572/8610 and compatible
+ *
+ * Copyright (C) 2008 Peter Korsgaard <jacmet@sunsite.dk>
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2.  This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/gpio.h>
+
+#define MPC8XXX_GPIO_PINS       32
+
+#define GPIO_DIR                0x00
+#define GPIO_ODR                0x04
+#define GPIO_DAT                0x08
+#define GPIO_IER                0x0c
+#define GPIO_IMR                0x10
+#define GPIO_ICR                0x14
+
+struct mpc8xxx_gpio_chip {
+        struct of_mm_gpio_chip mm_gc;
+        spinlock_t lock;
+
+        /*
+         * shadowed data register to be able to clear/set output pins in
+         * open drain mode safely
+         */
+        u32 data;
+};
+
+static inline u32 mpc8xxx_gpio2mask(unsigned int gpio)
+{
+        return 1u << (MPC8XXX_GPIO_PINS - 1 - gpio);
+}
+
+static inline struct mpc8xxx_gpio_chip *
+to_mpc8xxx_gpio_chip(struct of_mm_gpio_chip *mm)
+{
+        return container_of(mm, struct mpc8xxx_gpio_chip, mm_gc);
+}
+
+static void mpc8xxx_gpio_save_regs(struct of_mm_gpio_chip *mm)
+{
+        struct mpc8xxx_gpio_chip *mpc8xxx_gc = to_mpc8xxx_gpio_chip(mm);
+
+        mpc8xxx_gc->data = in_be32(mm->regs + GPIO_DAT);
+}
+
+static int mpc8xxx_gpio_get(struct gpio_chip *gc, unsigned int gpio)
+{
+        struct of_mm_gpio_chip *mm = to_of_mm_gpio_chip(gc);
+
+        return in_be32(mm->regs + GPIO_DAT) & mpc8xxx_gpio2mask(gpio);
+}
+
+static void mpc8xxx_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
+{
+        struct of_mm_gpio_chip *mm = to_of_mm_gpio_chip(gc);
+        struct mpc8xxx_gpio_chip *mpc8xxx_gc = to_mpc8xxx_gpio_chip(mm);
+        unsigned long flags;
+
+        spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
+
+        if (val)
+                mpc8xxx_gc->data |= mpc8xxx_gpio2mask(gpio);
+        else
+                mpc8xxx_gc->data &= ~mpc8xxx_gpio2mask(gpio);
+
+        out_be32(mm->regs + GPIO_DAT, mpc8xxx_gc->data);
+
+        spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
+}
+
+static int mpc8xxx_gpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
+{
+        struct of_mm_gpio_chip *mm = to_of_mm_gpio_chip(gc);
+        struct mpc8xxx_gpio_chip *mpc8xxx_gc = to_mpc8xxx_gpio_chip(mm);
+        unsigned long flags;
+
+        spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
+
+        clrbits32(mm->regs + GPIO_DIR, mpc8xxx_gpio2mask(gpio));
+
+        spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
+
+        return 0;
+}
+
+static int mpc8xxx_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
+{
+        struct of_mm_gpio_chip *mm = to_of_mm_gpio_chip(gc);
+        struct mpc8xxx_gpio_chip *mpc8xxx_gc = to_mpc8xxx_gpio_chip(mm);
+        unsigned long flags;
+
+        mpc8xxx_gpio_set(gc, gpio, val);
+
+        spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
+
+        setbits32(mm->regs + GPIO_DIR, mpc8xxx_gpio2mask(gpio));
+
+        spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
+
+        return 0;
+}
+
+static void __init mpc8xxx_add_controller(struct device_node *np)
+{
+        struct mpc8xxx_gpio_chip *mpc8xxx_gc;
+        struct of_mm_gpio_chip *mm_gc;
+        struct of_gpio_chip *of_gc;
+        struct gpio_chip *gc;
+        int ret;
+
+        mpc8xxx_gc = kzalloc(sizeof(*mpc8xxx_gc), GFP_KERNEL);
+        if (!mpc8xxx_gc) {
+                ret = -ENOMEM;
+                goto err;
+        }
+
+        spin_lock_init(&mpc8xxx_gc->lock);
+
+        mm_gc = &mpc8xxx_gc->mm_gc;
+        of_gc = &mm_gc->of_gc;
+        gc = &of_gc->gc;
+
+        mm_gc->save_regs = mpc8xxx_gpio_save_regs;
+        of_gc->gpio_cells = 2;
+        gc->ngpio = MPC8XXX_GPIO_PINS;
+        gc->direction_input = mpc8xxx_gpio_dir_in;
+        gc->direction_output = mpc8xxx_gpio_dir_out;
+        gc->get = mpc8xxx_gpio_get;
+        gc->set = mpc8xxx_gpio_set;
+
+        ret = of_mm_gpiochip_add(np, mm_gc);
+        if (ret)
+                goto err;
+
+        return;
+
+err:
+        pr_err("%s: registration failed with status %d\n",
+               np->full_name, ret);
+        kfree(mpc8xxx_gc);
+
+        return;
+}
+
+static int __init mpc8xxx_add_gpiochips(void)
+{
+        struct device_node *np;
+
+        for_each_compatible_node(np, NULL, "fsl,mpc8349-gpio")
+                mpc8xxx_add_controller(np);
+
+        for_each_compatible_node(np, NULL, "fsl,mpc8572-gpio")
+                mpc8xxx_add_controller(np);
+
+        for_each_compatible_node(np, NULL, "fsl,mpc8610-gpio")
+                mpc8xxx_add_controller(np);
+
+        return 0;
+}
+arch_initcall(mpc8xxx_add_gpiochips);