aboutsummaryrefslogtreecommitdiffstats
path: root/arch/mips/include/asm/mach-au1x00/gpio.h
diff options
context:
space:
mode:
Diffstat (limited to 'arch/mips/include/asm/mach-au1x00/gpio.h')
-rw-r--r--arch/mips/include/asm/mach-au1x00/gpio.h79
1 files changed, 76 insertions, 3 deletions
diff --git a/arch/mips/include/asm/mach-au1x00/gpio.h b/arch/mips/include/asm/mach-au1x00/gpio.h
index c3f60cd..fcdc8c4 100644
--- a/arch/mips/include/asm/mach-au1x00/gpio.h
+++ b/arch/mips/include/asm/mach-au1x00/gpio.h
@@ -1,10 +1,83 @@
+/*
+ * Alchemy GPIO support.
+ *
+ * With CONFIG_GPIOLIB=y different types of on-chip GPIO can be supported within
+ * the same kernel image.
+ * With CONFIG_GPIOLIB=n, your board must select ALCHEMY_GPIOINT_AU1XXX for the
+ * appropriate CPU type (AU1000 currently).
+ */
+
#ifndef _ALCHEMY_GPIO_H_
#define _ALCHEMY_GPIO_H_
-#if defined(CONFIG_ALCHEMY_GPIOINT_AU1000)
-
+#include <asm/mach-au1x00/au1000.h>
#include <asm/mach-au1x00/gpio-au1000.h>
-#endif
+/* On Au1000, Au1500 and Au1100 GPIOs won't work as inputs before
+ * SYS_PININPUTEN is written to at least once. On Au1550/Au1200/Au1300 this
+ * register enables use of GPIOs as wake source.
+ */
+static inline void alchemy_gpio1_input_enable(void)
+{
+ void __iomem *base = (void __iomem *)KSEG1ADDR(AU1000_SYS_PHYS_ADDR);
+ __raw_writel(0, base + 0x110); /* the write op is key */
+ wmb();
+}
+
+
+/* Linux gpio framework integration.
+*
+* 4 use cases of Alchemy GPIOS:
+*(1) GPIOLIB=y, ALCHEMY_GPIO_INDIRECT=y:
+* Board must register gpiochips.
+*(2) GPIOLIB=y, ALCHEMY_GPIO_INDIRECT=n:
+* A gpiochip for the 75 GPIOs is registered.
+*
+*(3) GPIOLIB=n, ALCHEMY_GPIO_INDIRECT=y:
+* the boards' gpio.h must provide the linux gpio wrapper functions,
+*
+*(4) GPIOLIB=n, ALCHEMY_GPIO_INDIRECT=n:
+* inlinable gpio functions are provided which enable access to the
+* Au1300 gpios only by using the numbers straight out of the data-
+* sheets.
+
+* Cases 1 and 3 are intended for boards which want to provide their own
+* GPIO namespace and -operations (i.e. for example you have 8 GPIOs
+* which are in part provided by spare Au1300 GPIO pins and in part by
+* an external FPGA but you still want them to be accssible in linux
+* as gpio0-7. The board can of course use the alchemy_gpioX_* functions
+* as required).
+*/
+
+#ifdef CONFIG_GPIOLIB
+
+/* wraps the cpu-dependent irq_to_gpio functions */
+/* FIXME: gpiolib needs an irq_to_gpio hook */
+static inline int __au_irq_to_gpio(unsigned int irq)
+{
+ switch (alchemy_get_cputype()) {
+ case ALCHEMY_CPU_AU1000...ALCHEMY_CPU_AU1200:
+ return alchemy_irq_to_gpio(irq);
+ }
+ return -EINVAL;
+}
+
+
+/* using gpiolib to provide up to 2 gpio_chips for on-chip gpios */
+#ifndef CONFIG_ALCHEMY_GPIO_INDIRECT /* case (2) */
+
+/* get everything through gpiolib */
+#define gpio_to_irq __gpio_to_irq
+#define gpio_get_value __gpio_get_value
+#define gpio_set_value __gpio_set_value
+#define gpio_cansleep __gpio_cansleep
+#define irq_to_gpio __au_irq_to_gpio
+
+#include <asm-generic/gpio.h>
+
+#endif /* !CONFIG_ALCHEMY_GPIO_INDIRECT */
+
+
+#endif /* CONFIG_GPIOLIB */
#endif /* _ALCHEMY_GPIO_H_ */