[ARM] 4988/1: Add GPIO lib support to the EP93xx

Adds support for the generic GPIO lib to the EP93xx family. The gpio
handling code has been moved from core.c to a new file called gpio.c.
The GPIO based IRQ code has not been changed.

Signed-off-by: Ryan Mallon <ryan@bluewatersys.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

3 files changed, 171 insertions, 98 deletions

diff --git a/arch/arm/mach-ep93xx/Makefile b/arch/arm/mach-ep93xx/Makefile
index 0ecf99761fe..c1252ca9648 100644
--- a/arch/arm/mach-ep93xx/Makefile
+++ b/arch/arm/mach-ep93xx/Makefile
@@ -1,7 +1,7 @@
 #
 # Makefile for the linux kernel.
 #
-obj-y                   := core.o clock.o
+obj-y                   := core.o clock.o gpio.o
 obj-m                   :=
 obj-n                   :=
 obj-                    :=
diff --git a/arch/arm/mach-ep93xx/core.c b/arch/arm/mach-ep93xx/core.c
index 91f6a07a51d..8bc18724054 100644
--- a/arch/arm/mach-ep93xx/core.c
+++ b/arch/arm/mach-ep93xx/core.c
@@ -159,7 +159,7 @@ static const u8 int_type2_register_offset[3]	= { 0x94, 0xb0, 0x50 };
 static const u8 eoi_register_offset[3]          = { 0x98, 0xb4, 0x54 };
 static const u8 int_en_register_offset[3]       = { 0x9c, 0xb8, 0x5c };
 
-static void update_gpio_int_params(unsigned port)
+void ep93xx_gpio_update_int_params(unsigned port)
 {
         BUG_ON(port > 2);
 
@@ -175,98 +175,10 @@ static void update_gpio_int_params(unsigned port)
                 EP93XX_GPIO_REG(int_en_register_offset[port]));
 }
 
-/* Port ordering is: A B F D E C G H */
-static const u8 data_register_offset[8] = {
-        0x00, 0x04, 0x30, 0x0c, 0x20, 0x08, 0x38, 0x40,
-};
-
-static const u8 data_direction_register_offset[8] = {
-        0x10, 0x14, 0x34, 0x1c, 0x24, 0x18, 0x3c, 0x44,
-};
-
-#define GPIO_IN         0
-#define GPIO_OUT        1
-
-static void ep93xx_gpio_set_direction(unsigned line, int direction)
-{
-        unsigned int data_direction_register;
-        unsigned long flags;
-        unsigned char v;
-
-        data_direction_register =
-                EP93XX_GPIO_REG(data_direction_register_offset[line >> 3]);
-
-        local_irq_save(flags);
-        if (direction == GPIO_OUT) {
-                if (line >= 0 && line <= EP93XX_GPIO_LINE_MAX_IRQ) {
-                        /* Port A/B/F */
-                        gpio_int_unmasked[line >> 3] &= ~(1 << (line & 7));
-                        update_gpio_int_params(line >> 3);
-                }
-
-                v = __raw_readb(data_direction_register);
-                v |= 1 << (line & 7);
-                __raw_writeb(v, data_direction_register);
-        } else if (direction == GPIO_IN) {
-                v = __raw_readb(data_direction_register);
-                v &= ~(1 << (line & 7));
-                __raw_writeb(v, data_direction_register);
-        }
-        local_irq_restore(flags);
-}
-
-int gpio_direction_input(unsigned gpio)
-{
-        if (gpio > EP93XX_GPIO_LINE_MAX)
-                return -EINVAL;
-
-        ep93xx_gpio_set_direction(gpio, GPIO_IN);
-
-        return 0;
-}
-EXPORT_SYMBOL(gpio_direction_input);
-
-int gpio_direction_output(unsigned gpio, int value)
-{
-        if (gpio > EP93XX_GPIO_LINE_MAX)
-                return -EINVAL;
-
-        gpio_set_value(gpio, value);
-        ep93xx_gpio_set_direction(gpio, GPIO_OUT);
-
-        return 0;
-}
-EXPORT_SYMBOL(gpio_direction_output);
-
-int gpio_get_value(unsigned gpio)
-{
-        unsigned int data_register;
-
-        data_register = EP93XX_GPIO_REG(data_register_offset[gpio >> 3]);
-
-        return !!(__raw_readb(data_register) & (1 << (gpio & 7)));
-}
-EXPORT_SYMBOL(gpio_get_value);
-
-void gpio_set_value(unsigned gpio, int value)
+void ep93xx_gpio_int_mask(unsigned line)
 {
-        unsigned int data_register;
-        unsigned long flags;
-        unsigned char v;
-
-        data_register = EP93XX_GPIO_REG(data_register_offset[gpio >> 3]);
-
-        local_irq_save(flags);
-        v = __raw_readb(data_register);
-        if (value)
-                v |= 1 << (gpio & 7);
-        else
-                v &= ~(1 << (gpio & 7));
-        __raw_writeb(v, data_register);
-        local_irq_restore(flags);
+        gpio_int_unmasked[line >> 3] &= ~(1 << (line & 7));
 }
-EXPORT_SYMBOL(gpio_set_value);
-
 
 /*************************************************************************
  * EP93xx IRQ handling
@@ -316,7 +228,7 @@ static void ep93xx_gpio_irq_ack(unsigned int irq)
 
         if ((irq_desc[irq].status & IRQ_TYPE_SENSE_MASK) == IRQT_BOTHEDGE) {
                 gpio_int_type2[port] ^= port_mask; /* switch edge direction */
-                update_gpio_int_params(port);
+                ep93xx_gpio_update_int_params(port);
         }
 
         __raw_writeb(port_mask, EP93XX_GPIO_REG(eoi_register_offset[port]));
@@ -332,7 +244,7 @@ static void ep93xx_gpio_irq_mask_ack(unsigned int irq)
                 gpio_int_type2[port] ^= port_mask; /* switch edge direction */
 
         gpio_int_unmasked[port] &= ~port_mask;
-        update_gpio_int_params(port);
+        ep93xx_gpio_update_int_params(port);
 
         __raw_writeb(port_mask, EP93XX_GPIO_REG(eoi_register_offset[port]));
 }
@@ -343,7 +255,7 @@ static void ep93xx_gpio_irq_mask(unsigned int irq)
         int port = line >> 3;
 
         gpio_int_unmasked[port] &= ~(1 << (line & 7));
-        update_gpio_int_params(port);
+        ep93xx_gpio_update_int_params(port);
 }
 
 static void ep93xx_gpio_irq_unmask(unsigned int irq)
@@ -352,7 +264,7 @@ static void ep93xx_gpio_irq_unmask(unsigned int irq)
         int port = line >> 3;
 
         gpio_int_unmasked[port] |= 1 << (line & 7);
-        update_gpio_int_params(port);
+        ep93xx_gpio_update_int_params(port);
 }
 
 
@@ -368,7 +280,7 @@ static int ep93xx_gpio_irq_type(unsigned int irq, unsigned int type)
         const int port = gpio >> 3;
         const int port_mask = 1 << (gpio & 7);
 
-        ep93xx_gpio_set_direction(gpio, GPIO_IN);
+        gpio_direction_output(gpio, gpio_get_value(gpio));
 
         switch (type) {
         case IRQT_RISING:
@@ -411,7 +323,7 @@ static int ep93xx_gpio_irq_type(unsigned int irq, unsigned int type)
         desc->status &= ~IRQ_TYPE_SENSE_MASK;
         desc->status |= type & IRQ_TYPE_SENSE_MASK;
 
-        update_gpio_int_params(port);
+        ep93xx_gpio_update_int_params(port);
 
         return 0;
 }
@@ -549,6 +461,7 @@ static struct platform_device ep93xx_ohci_device = {
         .resource       = ep93xx_ohci_resources,
 };
 
+extern void ep93xx_gpio_init(void);
 
 void __init ep93xx_init_devices(void)
 {
@@ -562,6 +475,8 @@ void __init ep93xx_init_devices(void)
         __raw_writel(0xaa, EP93XX_SYSCON_SWLOCK);
         __raw_writel(v, EP93XX_SYSCON_DEVICE_CONFIG);
 
+        ep93xx_gpio_init();
+
         amba_device_register(&uart1_device, &iomem_resource);
         amba_device_register(&uart2_device, &iomem_resource);
         amba_device_register(&uart3_device, &iomem_resource);
diff --git a/arch/arm/mach-ep93xx/gpio.c b/arch/arm/mach-ep93xx/gpio.c
new file mode 100644
index 00000000000..dc2e4c00d98
--- /dev/null
+++ b/arch/arm/mach-ep93xx/gpio.c
@@ -0,0 +1,158 @@
+/*
+ * linux/arch/arm/mach-ep93xx/gpio.c
+ *
+ * Generic EP93xx GPIO handling
+ *
+ * Copyright (c) 2008 Ryan Mallon <ryan@bluewatersys.com>
+ *
+ * Based on code originally from:
+ *  linux/arch/arm/mach-ep93xx/core.c
+ *
+ *  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/init.h>
+#include <linux/module.h>
+#include <linux/seq_file.h>
+
+#include <asm/arch/ep93xx-regs.h>
+#include <asm/io.h>
+#include <asm/gpio.h>
+
+struct ep93xx_gpio_chip {
+        struct gpio_chip        chip;
+
+        unsigned int            data_reg;
+        unsigned int            data_dir_reg;
+};
+
+#define to_ep93xx_gpio_chip(c) container_of(c, struct ep93xx_gpio_chip, chip)
+
+/* From core.c */
+extern void ep93xx_gpio_int_mask(unsigned line);
+extern void ep93xx_gpio_update_int_params(unsigned port);
+
+static int ep93xx_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
+{
+        struct ep93xx_gpio_chip *ep93xx_chip = to_ep93xx_gpio_chip(chip);
+        unsigned long flags;
+        u8 v;
+
+        local_irq_save(flags);
+        v = __raw_readb(ep93xx_chip->data_dir_reg);
+        v &= ~(1 << offset);
+        __raw_writeb(v, ep93xx_chip->data_dir_reg);
+        local_irq_restore(flags);
+
+        return 0;
+}
+
+static int ep93xx_gpio_direction_output(struct gpio_chip *chip,
+                                        unsigned offset, int val)
+{
+        struct ep93xx_gpio_chip *ep93xx_chip = to_ep93xx_gpio_chip(chip);
+        unsigned long flags;
+        int line;
+        u8 v;
+
+        local_irq_save(flags);
+
+        /* Set the value */
+        v = __raw_readb(ep93xx_chip->data_reg);
+        if (val)
+                v |= (1 << offset);
+        else
+                v &= ~(1 << offset);
+        __raw_writeb(v, ep93xx_chip->data_reg);
+
+        /* Drive as an output */
+        line = chip->base + offset;
+        if (line <= EP93XX_GPIO_LINE_MAX_IRQ) {
+                /* Ports A/B/F */
+                ep93xx_gpio_int_mask(line);
+                ep93xx_gpio_update_int_params(line >> 3);
+        }
+
+        v = __raw_readb(ep93xx_chip->data_dir_reg);
+        v |= (1 << offset);
+        __raw_writeb(v, ep93xx_chip->data_dir_reg);
+
+        local_irq_restore(flags);
+
+        return 0;
+}
+
+static int ep93xx_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+        struct ep93xx_gpio_chip *ep93xx_chip = to_ep93xx_gpio_chip(chip);
+
+        return !!(__raw_readb(ep93xx_chip->data_reg) & (1 << offset));
+}
+
+static void ep93xx_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
+{
+        struct ep93xx_gpio_chip *ep93xx_chip = to_ep93xx_gpio_chip(chip);
+        unsigned long flags;
+        u8 v;
+
+        local_irq_save(flags);
+        v = __raw_readb(ep93xx_chip->data_reg);
+        if (val)
+                v |= (1 << offset);
+        else
+                v &= ~(1 << offset);
+        __raw_writeb(v, ep93xx_chip->data_reg);
+        local_irq_restore(flags);
+}
+
+static void ep93xx_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
+{
+        struct ep93xx_gpio_chip *ep93xx_chip = to_ep93xx_gpio_chip(chip);
+        u8 data_reg, data_dir_reg;
+        int i;
+
+        data_reg = __raw_readb(ep93xx_chip->data_reg);
+        data_dir_reg = __raw_readb(ep93xx_chip->data_dir_reg);
+
+        for (i = 0; i < chip->ngpio; i++)
+                seq_printf(s, "GPIO %s%d: %s %s\n", chip->label, i,
+                           (data_reg & (1 << i)) ? "set" : "clear",
+                           (data_dir_reg & (1 << i)) ? "out" : "in");
+}
+
+#define EP93XX_GPIO_BANK(name, dr, ddr, base_gpio)                      \
+        {                                                               \
+                .chip = {                                               \
+                        .label            = name,                       \
+                        .direction_input  = ep93xx_gpio_direction_input, \
+                        .direction_output = ep93xx_gpio_direction_output, \
+                        .get              = ep93xx_gpio_get,            \
+                        .set              = ep93xx_gpio_set,            \
+                        .dbg_show         = ep93xx_gpio_dbg_show,       \
+                        .base             = base_gpio,                  \
+                        .ngpio            = 8,                          \
+                },                                                      \
+                .data_reg       = EP93XX_GPIO_REG(dr),                  \
+                .data_dir_reg   = EP93XX_GPIO_REG(ddr),                 \
+        }
+
+static struct ep93xx_gpio_chip ep93xx_gpio_banks[] = {
+        EP93XX_GPIO_BANK("A", 0x00, 0x10, 0),
+        EP93XX_GPIO_BANK("B", 0x04, 0x14, 8),
+        EP93XX_GPIO_BANK("C", 0x30, 0x34, 40),
+        EP93XX_GPIO_BANK("D", 0x0c, 0x1c, 24),
+        EP93XX_GPIO_BANK("E", 0x20, 0x24, 32),
+        EP93XX_GPIO_BANK("F", 0x08, 0x18, 16),
+        EP93XX_GPIO_BANK("G", 0x38, 0x3c, 48),
+        EP93XX_GPIO_BANK("H", 0x40, 0x44, 56),
+};
+
+void __init ep93xx_gpio_init(void)
+{
+        int i;
+
+        for (i = 0; i < ARRAY_SIZE(ep93xx_gpio_banks); i++)
+                gpiochip_add(&ep93xx_gpio_banks[i].chip);
+}