[ARM] 4590/1: ns9xxx: add gpio handling functions

This implementation conforms to the general GPIO API
introduced in 2.6.21.

This patch was signed-of by David Brownell before I exported the functions
using EXPORT_SYMBOL.

Signed-off-by: Uwe Kleine-König <ukleinek@informatik.uni-freiburg.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

3 files changed, 186 insertions, 1 deletions

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 691aae309c8a..6acc59da332d 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -318,6 +318,7 @@ config ARCH_KS8695
 
 config ARCH_NS9XXX
         bool "NetSilicon NS9xxx"
+        select GENERIC_GPIO
         help
           Say Y here if you intend to run this kernel on a NetSilicon NS9xxx
           System.
diff --git a/arch/arm/mach-ns9xxx/Makefile b/arch/arm/mach-ns9xxx/Makefile
index 4476411b8140..6fb82b855a55 100644
--- a/arch/arm/mach-ns9xxx/Makefile
+++ b/arch/arm/mach-ns9xxx/Makefile
@@ -1,4 +1,4 @@
-obj-y := irq.o time.o generic.o
+obj-y := irq.o time.o generic.o gpio.o
 
 obj-$(CONFIG_MACH_CC9P9360DEV) += mach-cc9p9360dev.o
 obj-$(CONFIG_MACH_CC9P9360JS) += mach-cc9p9360js.o
diff --git a/arch/arm/mach-ns9xxx/gpio.c b/arch/arm/mach-ns9xxx/gpio.c
new file mode 100644
index 000000000000..87b872fdca7e
--- /dev/null
+++ b/arch/arm/mach-ns9xxx/gpio.c
@@ -0,0 +1,184 @@
+/*
+ * arch/arm/mach-ns9xxx/gpio.c
+ *
+ * Copyright (C) 2006 by Digi International Inc.
+ * All rights reserved.
+ *
+ * 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.
+ */
+#include <linux/compiler.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/module.h>
+
+#include <asm/arch-ns9xxx/gpio.h>
+#include <asm/arch-ns9xxx/processor.h>
+#include <asm/arch-ns9xxx/regs-bbu.h>
+#include <asm/bug.h>
+#include <asm/types.h>
+#include <asm/bitops.h>
+
+#if defined(CONFIG_PROCESSOR_NS9360)
+#define GPIO_MAX 72
+#elif defined(CONFIG_PROCESSOR_NS9750)
+#define GPIO_MAX 49
+#endif
+
+/* protects BBU_GCONFx and BBU_GCTRLx */
+static spinlock_t gpio_lock = __SPIN_LOCK_UNLOCKED(gpio_lock);
+
+/* only access gpiores with atomic ops */
+static DECLARE_BITMAP(gpiores, GPIO_MAX);
+
+static inline int ns9xxx_valid_gpio(unsigned gpio)
+{
+#if defined(CONFIG_PROCESSOR_NS9360)
+        if (processor_is_ns9360())
+                return gpio <= 72;
+        else
+#endif
+#if defined(CONFIG_PROCESSOR_NS9750)
+        if (processor_is_ns9750())
+                return gpio <= 49;
+        else
+#endif
+                BUG();
+}
+
+static inline volatile u32 *ns9xxx_gpio_get_gconfaddr(unsigned gpio)
+{
+        if (gpio < 56)
+                return &BBU_GCONFb1(gpio / 8);
+        else
+                /*
+                 * this could be optimised away on
+                 * ns9750 only builds, but it isn't ...
+                 */
+                return &BBU_GCONFb2((gpio - 56) / 8);
+}
+
+static inline volatile u32 *ns9xxx_gpio_get_gctrladdr(unsigned gpio)
+{
+        if (gpio < 32)
+                return &BBU_GCTRL1;
+        else if (gpio < 64)
+                return &BBU_GCTRL2;
+        else
+                /* this could be optimised away on ns9750 only builds */
+                return &BBU_GCTRL3;
+}
+
+static inline volatile u32 *ns9xxx_gpio_get_gstataddr(unsigned gpio)
+{
+        if (gpio < 32)
+                return &BBU_GSTAT1;
+        else if (gpio < 64)
+                return &BBU_GSTAT2;
+        else
+                /* this could be optimised away on ns9750 only builds */
+                return &BBU_GSTAT3;
+}
+
+int gpio_request(unsigned gpio, const char *label)
+{
+        if (likely(ns9xxx_valid_gpio(gpio)))
+                return test_and_set_bit(gpio, gpiores) ? -EBUSY : 0;
+        else
+                return -EINVAL;
+}
+EXPORT_SYMBOL(gpio_request);
+
+void gpio_free(unsigned gpio)
+{
+        clear_bit(gpio, gpiores);
+        return;
+}
+EXPORT_SYMBOL(gpio_free);
+
+/*
+ * each gpio can serve for 4 different purposes [0..3].  These are called
+ * "functions" and passed in the parameter func.  Functions 0-2 are always some
+ * special things, function 3 is GPIO.  If func == 3 dir specifies input or
+ * output, and with inv you can enable an inverter (independent of func).
+ */
+static int __ns9xxx_gpio_configure(unsigned gpio, int dir, int inv, int func)
+{
+        volatile u32 *conf = ns9xxx_gpio_get_gconfaddr(gpio);
+        u32 confval;
+        unsigned long flags;
+
+        spin_lock_irqsave(&gpio_lock, flags);
+
+        confval = *conf;
+        REGSETIM_IDX(confval, BBU_GCONFx, DIR, gpio & 7, dir);
+        REGSETIM_IDX(confval, BBU_GCONFx, INV, gpio & 7, inv);
+        REGSETIM_IDX(confval, BBU_GCONFx, FUNC, gpio & 7, func);
+        *conf = confval;
+
+        spin_unlock_irqrestore(&gpio_lock, flags);
+
+        return 0;
+}
+
+int ns9xxx_gpio_configure(unsigned gpio, int inv, int func)
+{
+        if (likely(ns9xxx_valid_gpio(gpio))) {
+                if (func == 3) {
+                        printk(KERN_WARNING "use gpio_direction_input "
+                                        "or gpio_direction_output\n");
+                        return -EINVAL;
+                } else
+                        return __ns9xxx_gpio_configure(gpio, 0, inv, func);
+        } else
+                return -EINVAL;
+}
+EXPORT_SYMBOL(ns9xxx_gpio_configure);
+
+int gpio_direction_input(unsigned gpio)
+{
+        if (likely(ns9xxx_valid_gpio(gpio))) {
+                return __ns9xxx_gpio_configure(gpio, 0, 0, 3);
+        } else
+                return -EINVAL;
+}
+EXPORT_SYMBOL(gpio_direction_input);
+
+int gpio_direction_output(unsigned gpio, int value)
+{
+        if (likely(ns9xxx_valid_gpio(gpio))) {
+                gpio_set_value(gpio, value);
+
+                return __ns9xxx_gpio_configure(gpio, 1, 0, 3);
+        } else
+                return -EINVAL;
+}
+EXPORT_SYMBOL(gpio_direction_output);
+
+int gpio_get_value(unsigned gpio)
+{
+        volatile u32 *stat = ns9xxx_gpio_get_gstataddr(gpio);
+        int ret;
+
+        ret = 1 & (*stat >> (gpio & 31));
+
+        return ret;
+}
+EXPORT_SYMBOL(gpio_get_value);
+
+void gpio_set_value(unsigned gpio, int value)
+{
+        volatile u32 *ctrl = ns9xxx_gpio_get_gctrladdr(gpio);
+        unsigned long flags;
+
+        spin_lock_irqsave(&gpio_lock, flags);
+
+        if (value)
+                *ctrl |= 1 << (gpio & 31);
+        else
+                *ctrl &= ~(1 << (gpio & 31));
+
+        spin_unlock_irqrestore(&gpio_lock, flags);
+}
+EXPORT_SYMBOL(gpio_set_value);