[MIPS] rbtx4938: Add generic GPIO support

GPIO 0..15 are for TX4938 PIO pins, GPIO 16..18 are for FPGA-driven
chipselect signals for SPI devices.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

3 files changed, 106 insertions, 0 deletions

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 24661d60bc8f..823a6285c55a 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -660,6 +660,7 @@ config TOSHIBA_RBTX4938
         select SYS_SUPPORTS_BIG_ENDIAN
         select SYS_SUPPORTS_KGDB
         select GENERIC_HARDIRQS_NO__DO_IRQ
+        select GENERIC_GPIO
         help
           This Toshiba board is based on the TX4938 processor. Say Y here to
           support this machine type
diff --git a/arch/mips/configs/rbhma4500_defconfig b/arch/mips/configs/rbhma4500_defconfig
index b0abd16fae29..6e10c15cecf7 100644
--- a/arch/mips/configs/rbhma4500_defconfig
+++ b/arch/mips/configs/rbhma4500_defconfig
@@ -80,6 +80,7 @@ CONFIG_DMA_NONCOHERENT=y
 CONFIG_DMA_NEED_PCI_MAP_STATE=y
 CONFIG_GENERIC_ISA_DMA=y
 CONFIG_I8259=y
+CONFIG_GENERIC_GPIO=y
 # CONFIG_CPU_BIG_ENDIAN is not set
 CONFIG_CPU_LITTLE_ENDIAN=y
 CONFIG_SYS_SUPPORTS_BIG_ENDIAN=y
diff --git a/arch/mips/tx4938/toshiba_rbtx4938/setup.c b/arch/mips/tx4938/toshiba_rbtx4938/setup.c
index f5d1ce739fcc..12b9f4f9c3a2 100644
--- a/arch/mips/tx4938/toshiba_rbtx4938/setup.c
+++ b/arch/mips/tx4938/toshiba_rbtx4938/setup.c
@@ -29,6 +29,7 @@
 #include <asm/uaccess.h>
 #include <asm/io.h>
 #include <asm/bootinfo.h>
+#include <asm/gpio.h>
 #include <asm/tx4938/rbtx4938.h>
 #ifdef CONFIG_SERIAL_TXX9
 #include <linux/tty.h>
@@ -1057,3 +1058,106 @@ static int __init rbtx4938_ne_init(void)
         return IS_ERR(dev) ? PTR_ERR(dev) : 0;
 }
 device_initcall(rbtx4938_ne_init);
+
+/* GPIO support */
+
+static DEFINE_SPINLOCK(rbtx4938_spi_gpio_lock);
+
+static void rbtx4938_spi_gpio_set(unsigned gpio, int value)
+{
+        u8 val;
+        unsigned long flags;
+        gpio -= 16;
+        spin_lock_irqsave(&rbtx4938_spi_gpio_lock, flags);
+        val = *rbtx4938_spics_ptr;
+        if (value)
+                val |= 1 << gpio;
+        else
+                val &= ~(1 << gpio);
+        *rbtx4938_spics_ptr = val;
+        mmiowb();
+        spin_unlock_irqrestore(&rbtx4938_spi_gpio_lock, flags);
+}
+
+static int rbtx4938_spi_gpio_dir_out(unsigned gpio, int value)
+{
+        rbtx4938_spi_gpio_set(gpio, value);
+        return 0;
+}
+
+static DEFINE_SPINLOCK(tx4938_gpio_lock);
+
+static int tx4938_gpio_get(unsigned gpio)
+{
+        return tx4938_pioptr->din & (1 << gpio);
+}
+
+static void tx4938_gpio_set_raw(unsigned gpio, int value)
+{
+        u32 val;
+        val = tx4938_pioptr->dout;
+        if (value)
+                val |= 1 << gpio;
+        else
+                val &= ~(1 << gpio);
+        tx4938_pioptr->dout = val;
+}
+
+static void tx4938_gpio_set(unsigned gpio, int value)
+{
+        unsigned long flags;
+        spin_lock_irqsave(&tx4938_gpio_lock, flags);
+        tx4938_gpio_set_raw(gpio, value);
+        mmiowb();
+        spin_unlock_irqrestore(&tx4938_gpio_lock, flags);
+}
+
+static int tx4938_gpio_dir_in(unsigned gpio)
+{
+        spin_lock_irq(&tx4938_gpio_lock);
+        tx4938_pioptr->dir &= ~(1 << gpio);
+        mmiowb();
+        spin_unlock_irq(&tx4938_gpio_lock);
+        return 0;
+}
+
+static int tx4938_gpio_dir_out(unsigned int gpio, int value)
+{
+        spin_lock_irq(&tx4938_gpio_lock);
+        tx4938_gpio_set_raw(gpio, value);
+        tx4938_pioptr->dir |= 1 << gpio;
+        mmiowb();
+        spin_unlock_irq(&tx4938_gpio_lock);
+        return 0;
+}
+
+int gpio_direction_input(unsigned gpio)
+{
+        if (gpio < 16)
+                return tx4938_gpio_dir_in(gpio);
+        return -EINVAL;
+}
+
+int gpio_direction_output(unsigned gpio, int value)
+{
+        if (gpio < 16)
+                return tx4938_gpio_dir_out(gpio, value);
+        if (gpio < 16 + 3)
+                return rbtx4938_spi_gpio_dir_out(gpio, value);
+        return -EINVAL;
+}
+
+int gpio_get_value(unsigned gpio)
+{
+        if (gpio < 16)
+                return tx4938_gpio_get(gpio);
+        return 0;
+}
+
+void gpio_set_value(unsigned gpio, int value)
+{
+        if (gpio < 16)
+                tx4938_gpio_set(gpio, value);
+        else
+                rbtx4938_spi_gpio_set(gpio, value);
+}