From: Oskar Schirmer <[email protected]>
Implement the s6000 gpio controller as a chip for the generic gpio
lib.
Signed-off-by: Oskar Schirmer <[email protected]>
Signed-off-by: Johannes Weiner <[email protected]>
---
arch/xtensa/Kconfig | 4 ++
arch/xtensa/include/asm/gpio.h | 56 ++++++++++++++++++++++++++++
arch/xtensa/variants/s6000/Makefile | 2 -
arch/xtensa/variants/s6000/gpio.c | 71 ++++++++++++++++++++++++++++++++++++
4 files changed, 132 insertions(+), 1 deletion(-)
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -32,6 +32,9 @@ config GENERIC_HWEIGHT
config GENERIC_HARDIRQS
def_bool y
+config GENERIC_GPIO
+ def_bool y
+
config ARCH_HAS_ILOG2_U32
def_bool n
@@ -73,6 +76,7 @@ config XTENSA_VARIANT_DC232B
config XTENSA_VARIANT_S6000
bool "s6000 - Stretch software configurable processor"
select VARIANT_IRQ_SWITCH
+ select ARCH_REQUIRE_GPIOLIB
endchoice
config XTENSA_UNALIGNED_USER
--- /dev/null
+++ b/arch/xtensa/include/asm/gpio.h
@@ -0,0 +1,56 @@
+/*
+ * Generic GPIO API implementation for xtensa.
+ *
+ * Stolen from x86, which is derived from the generic GPIO API for powerpc:
+ *
+ * Copyright (c) 2007-2008 MontaVista Software, Inc.
+ *
+ * Author: Anton Vorontsov <[email protected]>
+ *
+ * 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.
+ */
+
+#ifndef _ASM_XTENSA_GPIO_H
+#define _ASM_XTENSA_GPIO_H
+
+#include <asm-generic/gpio.h>
+
+#ifdef CONFIG_GPIOLIB
+
+/*
+ * Just call gpiolib.
+ */
+static inline int gpio_get_value(unsigned int gpio)
+{
+ return __gpio_get_value(gpio);
+}
+
+static inline void gpio_set_value(unsigned int gpio, int value)
+{
+ __gpio_set_value(gpio, value);
+}
+
+static inline int gpio_cansleep(unsigned int gpio)
+{
+ return __gpio_cansleep(gpio);
+}
+
+/*
+ * Not implemented, yet.
+ */
+static inline int gpio_to_irq(unsigned int gpio)
+{
+ return -ENOSYS;
+}
+
+static inline int irq_to_gpio(unsigned int irq)
+{
+ return -EINVAL;
+}
+
+#endif /* CONFIG_GPIOLIB */
+
+#endif /* _ASM_XTENSA_GPIO_H */
--- a/arch/xtensa/variants/s6000/Makefile
+++ b/arch/xtensa/variants/s6000/Makefile
@@ -1,3 +1,3 @@
# s6000 Makefile
-obj-y += irq.o
+obj-y += irq.o gpio.o
--- /dev/null
+++ b/arch/xtensa/variants/s6000/gpio.c
@@ -0,0 +1,71 @@
+/*
+ * s6000 gpio driver
+ *
+ * Copyright (c) 2009 emlix GmbH
+ * Authors: Oskar Schirmer <[email protected]>
+ * Johannes Weiner <[email protected]>
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/gpio.h>
+
+#include <variant/hardware.h>
+
+#define S6_GPIO_DATA 0x000
+#define S6_GPIO_IS 0x404
+#define S6_GPIO_IBE 0x408
+#define S6_GPIO_IEV 0x40C
+#define S6_GPIO_IE 0x410
+#define S6_GPIO_RIS 0x414
+#define S6_GPIO_MIS 0x418
+#define S6_GPIO_IC 0x41C
+#define S6_GPIO_AFSEL 0x420
+#define S6_GPIO_DIR 0x800
+#define S6_GPIO_BANK(nr) ((nr) * 0x1000)
+#define S6_GPIO_MASK(nr) (4 << (nr))
+#define S6_GPIO_OFFSET(nr) \
+ (S6_GPIO_BANK((nr) >> 3) + S6_GPIO_MASK((nr) & 7))
+
+static int direction_input(struct gpio_chip *chip, unsigned int off)
+{
+ writeb(0, S6_REG_GPIO + S6_GPIO_DIR + S6_GPIO_OFFSET(off));
+ return 0;
+}
+
+static int get(struct gpio_chip *chip, unsigned int off)
+{
+ return readb(S6_REG_GPIO + S6_GPIO_DATA + S6_GPIO_OFFSET(off));
+}
+
+static int direction_output(struct gpio_chip *chip, unsigned int off, int val)
+{
+ unsigned rel = S6_GPIO_OFFSET(off);
+ writeb(~0, S6_REG_GPIO + S6_GPIO_DIR + rel);
+ writeb(val ? ~0 : 0, S6_REG_GPIO + S6_GPIO_DATA + rel);
+ return 0;
+}
+
+static void set(struct gpio_chip *chip, unsigned int off, int val)
+{
+ writeb(val ? ~0 : 0, S6_REG_GPIO + S6_GPIO_DATA + S6_GPIO_OFFSET(off));
+}
+
+static struct gpio_chip gpiochip = {
+ .owner = THIS_MODULE,
+ .direction_input = direction_input,
+ .get = get,
+ .direction_output = direction_output,
+ .set = set,
+ .base = 0,
+ .ngpio = 24,
+ .can_sleep = 0, /* no blocking io needed */
+ .exported = 0, /* no exporting to userspace */
+};
+
+static int gpio_init(void)
+{
+ return gpiochip_add(&gpiochip);
+}
+device_initcall(gpio_init);
--