2011/7/26 Russell King - ARM Linux [off-list ref]:

On Tue, Jul 26, 2011 at 01:13:13AM -0700, Barry Song wrote:

quoted

diff --git a/arch/arm/mach-prima2/include/mach/gpio.h b/arch/arm/mach-prima2/include/mach/gpio.h
new file mode 100644
index 0000000..25673b1
--- /dev/null
+++ b/arch/arm/mach-prima2/include/mach/gpio.h

@@ -0,0 +1,34 @@
+/*
+ * arch/arm/mach-prima2/include/mach/gpio.h
+ *
+ * Copyright (c) 2011 Cambridge Silicon Radio Limited, a CSR plc group company.
+ *
+ * Licensed under GPLv2 or later.
+ */
+
+#ifndef __MACH_GPIO_H
+#define __MACH_GPIO_H
+
+#include <mach/irqs.h>
+
+#ifndef CONFIG_GPIO_SIRFCPLD
+#define ARCH_NR_GPIOS ? ? ? ?(SIRFSOC_GPIO_BANK_SIZE * SIRFSOC_GPIO_NO_OF_BANKS)
+#else
+#define ARCH_NR_GPIOS ? ? ? ?(SIRFSOC_GPIO_BANK_SIZE * SIRFSOC_GPIO_NO_OF_BANKS + \
+ ? ? SIRFSOC_GPIO_CPLD_SIZE + SIRFSOC_GPIO_IO_CPLD_SIZE + \
+ ? ? SIRFSOC_GPIO_HS_CPLD_SIZE)
+#endif
+
+#include <linux/errno.h>

Why do you need linux/errno.h? ?asm-generic/gpio.h already includes this.

quoted

+#include <asm-generic/gpio.h>
+
+#define gpio_get_value ? ? ? __gpio_get_value
+#define gpio_set_value ? ? ? __gpio_set_value
+#define gpio_cansleep ? ? ? ?__gpio_cansleep

Hmm, yet another trivial gpio implementation. ?We have 24 others just like
this. ?Well, mainline does... I have just one.

Ok.
this gpio driver includes two parts: gpio chip and irq chip.  For gpio
chip, we could import gpio-generic and delete
sirfsoc_gpio_direction_input, sirfsoc_gpio_get_value,
sirfsoc_gpio_direction_output and so on.
For the part of irq chip, i don't see much benefit from generic-irq.
all of sirfsoc_gpio_irq_ack, sirfsoc_gpio_irq_mask and
sirfsoc_gpio_irq_unmask are CSR-specific.  irq_gc_ack_set_bit,
irq_gc_mask_clr_bit and irq_gc_mask_set_bit are not practicable to
this chip.

-barry