powerpc/4xx: Add PowerPC 4xx GPIO driver

This patch adds support for the GPIO functions of PPC40x and PPC44x
SOCs.

Signed-off-by: Steve Falco <sfalco@harris.com>
Acked-by: Stefan Roese <sr@denx.de>
Acked-by: Sean MacLennan <smaclennan@pikatech.com>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>

2 files changed, 218 insertions, 0 deletions

diff --git a/arch/powerpc/sysdev/Makefile b/arch/powerpc/sysdev/Makefile
index a44709a94f97..5afce115ab1f 100644
--- a/arch/powerpc/sysdev/Makefile
+++ b/arch/powerpc/sysdev/Makefile
@@ -37,6 +37,7 @@ obj-$(CONFIG_OF_RTC)		+= of_rtc.o
 ifeq ($(CONFIG_PCI),y)
 obj-$(CONFIG_4xx)               += ppc4xx_pci.o
 endif
+obj-$(CONFIG_PPC4xx_GPIO)       += ppc4xx_gpio.o
 
 obj-$(CONFIG_CPM)               += cpm_common.o
 obj-$(CONFIG_CPM2)              += cpm2.o cpm2_pic.o
diff --git a/arch/powerpc/sysdev/ppc4xx_gpio.c b/arch/powerpc/sysdev/ppc4xx_gpio.c
new file mode 100644
index 000000000000..110efe2a54fc
--- /dev/null
+++ b/arch/powerpc/sysdev/ppc4xx_gpio.c
@@ -0,0 +1,217 @@
+/*
+ * PPC4xx gpio driver
+ *
+ * Copyright (c) 2008 Harris Corporation
+ * Copyright (c) 2008 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix
+ * Copyright (c) MontaVista Software, Inc. 2008.
+ *
+ * Author: Steve Falco <sfalco@harris.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#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>
+#include <linux/types.h>
+
+#define GPIO_MASK(gpio)         (0x80000000 >> (gpio))
+#define GPIO_MASK2(gpio)        (0xc0000000 >> ((gpio) * 2))
+
+/* Physical GPIO register layout */
+struct ppc4xx_gpio {
+        __be32 or;
+        __be32 tcr;
+        __be32 osrl;
+        __be32 osrh;
+        __be32 tsrl;
+        __be32 tsrh;
+        __be32 odr;
+        __be32 ir;
+        __be32 rr1;
+        __be32 rr2;
+        __be32 rr3;
+        __be32 reserved1;
+        __be32 isr1l;
+        __be32 isr1h;
+        __be32 isr2l;
+        __be32 isr2h;
+        __be32 isr3l;
+        __be32 isr3h;
+};
+
+struct ppc4xx_gpio_chip {
+        struct of_mm_gpio_chip mm_gc;
+        spinlock_t lock;
+};
+
+/*
+ * GPIO LIB API implementation for GPIOs
+ *
+ * There are a maximum of 32 gpios in each gpio controller.
+ */
+
+static inline struct ppc4xx_gpio_chip *
+to_ppc4xx_gpiochip(struct of_mm_gpio_chip *mm_gc)
+{
+        return container_of(mm_gc, struct ppc4xx_gpio_chip, mm_gc);
+}
+
+static int ppc4xx_gpio_get(struct gpio_chip *gc, unsigned int gpio)
+{
+        struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
+        struct ppc4xx_gpio __iomem *regs = mm_gc->regs;
+
+        return in_be32(&regs->ir) & GPIO_MASK(gpio);
+}
+
+static inline void
+__ppc4xx_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
+{
+        struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
+        struct ppc4xx_gpio __iomem *regs = mm_gc->regs;
+
+        if (val)
+                setbits32(&regs->or, GPIO_MASK(gpio));
+        else
+                clrbits32(&regs->or, GPIO_MASK(gpio));
+}
+
+static void
+ppc4xx_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
+{
+        struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
+        struct ppc4xx_gpio_chip *chip = to_ppc4xx_gpiochip(mm_gc);
+        unsigned long flags;
+
+        spin_lock_irqsave(&chip->lock, flags);
+
+        __ppc4xx_gpio_set(gc, gpio, val);
+
+        spin_unlock_irqrestore(&chip->lock, flags);
+
+        pr_debug("%s: gpio: %d val: %d\n", __func__, gpio, val);
+}
+
+static int ppc4xx_gpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
+{
+        struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
+        struct ppc4xx_gpio_chip *chip = to_ppc4xx_gpiochip(mm_gc);
+        struct ppc4xx_gpio __iomem *regs = mm_gc->regs;
+        unsigned long flags;
+
+        spin_lock_irqsave(&chip->lock, flags);
+
+        /* Disable open-drain function */
+        clrbits32(&regs->odr, GPIO_MASK(gpio));
+
+        /* Float the pin */
+        clrbits32(&regs->tcr, GPIO_MASK(gpio));
+
+        /* Bits 0-15 use TSRL/OSRL, bits 16-31 use TSRH/OSRH */
+        if (gpio < 16) {
+                clrbits32(&regs->osrl, GPIO_MASK2(gpio));
+                clrbits32(&regs->tsrl, GPIO_MASK2(gpio));
+        } else {
+                clrbits32(&regs->osrh, GPIO_MASK2(gpio));
+                clrbits32(&regs->tsrh, GPIO_MASK2(gpio));
+        }
+
+        spin_unlock_irqrestore(&chip->lock, flags);
+
+        return 0;
+}
+
+static int
+ppc4xx_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
+{
+        struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
+        struct ppc4xx_gpio_chip *chip = to_ppc4xx_gpiochip(mm_gc);
+        struct ppc4xx_gpio __iomem *regs = mm_gc->regs;
+        unsigned long flags;
+
+        spin_lock_irqsave(&chip->lock, flags);
+
+        /* First set initial value */
+        __ppc4xx_gpio_set(gc, gpio, val);
+
+        /* Disable open-drain function */
+        clrbits32(&regs->odr, GPIO_MASK(gpio));
+
+        /* Drive the pin */
+        setbits32(&regs->tcr, GPIO_MASK(gpio));
+
+        /* Bits 0-15 use TSRL, bits 16-31 use TSRH */
+        if (gpio < 16) {
+                clrbits32(&regs->osrl, GPIO_MASK2(gpio));
+                clrbits32(&regs->tsrl, GPIO_MASK2(gpio));
+        } else {
+                clrbits32(&regs->osrh, GPIO_MASK2(gpio));
+                clrbits32(&regs->tsrh, GPIO_MASK2(gpio));
+        }
+
+        spin_unlock_irqrestore(&chip->lock, flags);
+
+        pr_debug("%s: gpio: %d val: %d\n", __func__, gpio, val);
+
+        return 0;
+}
+
+static int __init ppc4xx_add_gpiochips(void)
+{
+        struct device_node *np;
+
+        for_each_compatible_node(np, NULL, "ibm,ppc4xx-gpio") {
+                int ret;
+                struct ppc4xx_gpio_chip *ppc4xx_gc;
+                struct of_mm_gpio_chip *mm_gc;
+                struct of_gpio_chip *of_gc;
+                struct gpio_chip *gc;
+
+                ppc4xx_gc = kzalloc(sizeof(*ppc4xx_gc), GFP_KERNEL);
+                if (!ppc4xx_gc) {
+                        ret = -ENOMEM;
+                        goto err;
+                }
+
+                spin_lock_init(&ppc4xx_gc->lock);
+
+                mm_gc = &ppc4xx_gc->mm_gc;
+                of_gc = &mm_gc->of_gc;
+                gc = &of_gc->gc;
+
+                of_gc->gpio_cells = 2;
+                gc->ngpio = 32;
+                gc->direction_input = ppc4xx_gpio_dir_in;
+                gc->direction_output = ppc4xx_gpio_dir_out;
+                gc->get = ppc4xx_gpio_get;
+                gc->set = ppc4xx_gpio_set;
+
+                ret = of_mm_gpiochip_add(np, mm_gc);
+                if (ret)
+                        goto err;
+                continue;
+err:
+                pr_err("%s: registration failed with status %d\n",
+                       np->full_name, ret);
+                kfree(ppc4xx_gc);
+                /* try others anyway */
+        }
+        return 0;
+}
+arch_initcall(ppc4xx_add_gpiochips);