[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>

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.

arch/arm/mach-ns9xxx/Makefile

-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

arch/arm/mach-ns9xxx/gpio.c

+/*
+ * 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);

include/asm-arm/arch-ns9xxx/gpio.h

+/*
+ * include/asm-arm/arch-ns9xxx/gpio.h
+ *
+ * Copyright (C) 2007 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.
+*/
+#ifndef __ASM_ARCH_GPIO_H
+#define __ASM_ARCH_GPIO_H
+
+#include <asm/errno.h>
+
+int gpio_request(unsigned gpio, const char *label);
+
+void gpio_free(unsigned gpio);
+
+int ns9xxx_gpio_configure(unsigned gpio, int inv, int func);
+
+int gpio_direction_input(unsigned gpio);
+
+int gpio_direction_output(unsigned gpio, int value);
+
+int gpio_get_value(unsigned gpio);
+
+void gpio_set_value(unsigned gpio, int value);
+
+/*
+ * ns9xxx can use gpio pins to trigger an irq, but it's not generic
+ * enough to be supported by the gpio_to_irq/irq_to_gpio interface
+ */
+static inline int gpio_to_irq(unsigned gpio)
+{
+	return -EINVAL;
+}
+
+static inline int irq_to_gpio(unsigned irq)
+{
+	return -EINVAL;
+}
+
+/* get the cansleep() stubs */
+#include <asm-generic/gpio.h>
+
+#endif /* ifndef __ASM_ARCH_GPIO_H */