ARM: 7024/1: simpad: Cleanup CS3 accessors.

- prepend CS3 accessors by simpad_ to indicate they
  are specific to simpad devices.
- use spinlock to protect shadow register.
- implement 8 read-only pins.
- use readl/writel macros so barriers are used where
  necessary.
- register CS3 as GPIO controller with 24 pins
  (16 output only and 8 input only).
- fix PCMCIA driver to access the read-only pins
  rather than the shadow register for status bits.

Signed-off-by: Jochen Friedrich <jochen@scram.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 93 insertions, 24 deletions

diff --git a/arch/arm/mach-sa1100/simpad.c b/arch/arm/mach-sa1100/simpad.c
index 718b802bbff3..c3c66b0d6b6e 100644
--- a/arch/arm/mach-sa1100/simpad.c
+++ b/arch/arm/mach-sa1100/simpad.c
@@ -13,6 +13,7 @@
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/partitions.h>
 #include <linux/io.h>
+#include <linux/gpio.h>
 
 #include <asm/irq.h>
 #include <mach/hardware.h>
@@ -31,32 +32,85 @@
 
 #include "generic.h"
 
-long cs3_shadow;
+/*
+ * CS3 support
+ */
+
+static long cs3_shadow;
+static spinlock_t cs3_lock;
+static struct gpio_chip cs3_gpio;
+
+long simpad_get_cs3_ro(void)
+{
+	return readl(CS3_BASE);
+}
+EXPORT_SYMBOL(simpad_get_cs3_ro);
 
-long get_cs3_shadow(void)
+long simpad_get_cs3_shadow(void)
 {
 	return cs3_shadow;
 }
+EXPORT_SYMBOL(simpad_get_cs3_shadow);
 
-void set_cs3(long value)
+static void __simpad_write_cs3(void)
 {
-	*(CS3BUSTYPE *)(CS3_BASE) = cs3_shadow = value;
+	writel(cs3_shadow, CS3_BASE);
 }
 
-void set_cs3_bit(int value)
+void simpad_set_cs3_bit(int value)
 {
+	unsigned long flags;
+
+	spin_lock_irqsave(&cs3_lock, flags);
 	cs3_shadow |= value;
-	*(CS3BUSTYPE *)(CS3_BASE) = cs3_shadow;
+	__simpad_write_cs3();
+	spin_unlock_irqrestore(&cs3_lock, flags);
 }
+EXPORT_SYMBOL(simpad_set_cs3_bit);
 
-void clear_cs3_bit(int value)
+void simpad_clear_cs3_bit(int value)
 {
+	unsigned long flags;
+
+	spin_lock_irqsave(&cs3_lock, flags);
 	cs3_shadow &= ~value;
-	*(CS3BUSTYPE *)(CS3_BASE) = cs3_shadow;
+	__simpad_write_cs3();
+	spin_unlock_irqrestore(&cs3_lock, flags);
 }
+EXPORT_SYMBOL(simpad_clear_cs3_bit);
+
+static void cs3_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+	if (offset > 15)
+		return;
+	if (value)
+		simpad_set_cs3_bit(1 << offset);
+	else
+		simpad_clear_cs3_bit(1 << offset);
+};
 
-EXPORT_SYMBOL(set_cs3_bit);
-EXPORT_SYMBOL(clear_cs3_bit);
+static int cs3_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+	if (offset > 15)
+		return simpad_get_cs3_ro() & (1 << (offset - 16));
+	return simpad_get_cs3_shadow() & (1 << offset);
+};
+
+static int cs3_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
+{
+	if (offset > 15)
+		return 0;
+	return -EINVAL;
+};
+
+static int cs3_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
+	int value)
+{
+	if (offset > 15)
+		return -EINVAL;
+	cs3_gpio_set(chip, offset, value);
+	return 0;
+};
 
 static struct map_desc simpad_io_desc[] __initdata = {
 	{	/* MQ200 */
@@ -64,9 +118,9 @@ static struct map_desc simpad_io_desc[] __initdata = {
 		.pfn		= __phys_to_pfn(0x4b800000),
 		.length		= 0x00800000,
 		.type		= MT_DEVICE
-	}, {	/* Paules CS3, write only */
-		.virtual	=  0xf1000000,
-		.pfn		= __phys_to_pfn(0x18000000),
+	}, {	/* Simpad CS3 */
+		.virtual	= CS3_BASE,
+		.pfn		= __phys_to_pfn(SA1100_CS3_PHYS),
 		.length		= 0x00100000,
 		.type		= MT_DEVICE
 	},
@@ -78,12 +132,12 @@ static void simpad_uart_pm(struct uart_port *port, u_int state, u_int oldstate)
 	if (port->mapbase == (u_int)&Ser1UTCR0) {
 		if (state)
 		{
-			clear_cs3_bit(RS232_ON);
-			clear_cs3_bit(DECT_POWER_ON);
+			simpad_clear_cs3_bit(RS232_ON);
+			simpad_clear_cs3_bit(DECT_POWER_ON);
 		}else
 		{
-			set_cs3_bit(RS232_ON);
-			set_cs3_bit(DECT_POWER_ON);
+			simpad_set_cs3_bit(RS232_ON);
+			simpad_set_cs3_bit(DECT_POWER_ON);
 		}
 	}
 }
@@ -143,9 +197,10 @@ static void __init simpad_map_io(void)
 
 	iotable_init(simpad_io_desc, ARRAY_SIZE(simpad_io_desc));
 
-	set_cs3_bit (EN1 | EN0 | LED2_ON | DISPLAY_ON | RS232_ON |
-		      ENABLE_5V | RESET_SIMCARD | DECT_POWER_ON);
-
+	/* Initialize CS3 */
+	cs3_shadow = (EN1 | EN0 | LED2_ON | DISPLAY_ON |
+		RS232_ON | ENABLE_5V | RESET_SIMCARD | DECT_POWER_ON);
+	__simpad_write_cs3(); /* Spinlocks not yet initialized */
 
         sa1100_register_uart_fns(&simpad_port_fns);
 	sa1100_register_uart(0, 3);  /* serial interface */
@@ -171,13 +226,14 @@ static void __init simpad_map_io(void)
 
 static void simpad_power_off(void)
 {
-	local_irq_disable(); // was cli
-	set_cs3(0x800);        /* only SD_MEDIAQ */
+	local_irq_disable();
+	cs3_shadow = SD_MEDIAQ;
+	__simpad_write_cs3(); /* Bypass spinlock here */
 
 	/* disable internal oscillator, float CS lines */
 	PCFR = (PCFR_OPDE | PCFR_FP | PCFR_FS);
-	/* enable wake-up on GPIO0 (Assabet...) */
-	PWER = GFER = GRER = 1;
+	/* enable wake-up on GPIO0 */
+	PWER = GFER = GRER = PWER_GPIO0;
 	/*
 	 * set scratchpad to zero, just in case it is used as a
 	 * restart address by the bootloader.
@@ -212,6 +268,19 @@ static int __init simpad_init(void)
 {
 	int ret;
 
+	spin_lock_init(&cs3_lock);
+
+	cs3_gpio.label = "simpad_cs3";
+	cs3_gpio.base = SIMPAD_CS3_GPIO_BASE;
+	cs3_gpio.ngpio = 24;
+	cs3_gpio.set = cs3_gpio_set;
+	cs3_gpio.get = cs3_gpio_get;
+	cs3_gpio.direction_input = cs3_gpio_direction_input;
+	cs3_gpio.direction_output = cs3_gpio_direction_output;
+	ret = gpiochip_add(&cs3_gpio);
+	if (ret)
+		printk(KERN_WARNING "simpad: Unable to register cs3 GPIO device");
+
 	pm_power_off = simpad_power_off;
 
 	sa11x0_register_mtd(&simpad_flash_data, simpad_flash_resources,