diff options
Diffstat (limited to 'include')
-rw-r--r-- | include/fdtdec.h | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/include/fdtdec.h b/include/fdtdec.h index a4467000b7..2f3842d9a3 100644 --- a/include/fdtdec.h +++ b/include/fdtdec.h @@ -61,6 +61,23 @@ enum fdt_compat_id { COMPAT_COUNT, }; +/* GPIOs are numbered from 0 */ +enum { + FDT_GPIO_NONE = -1U, /* an invalid GPIO used to end our list */ + + FDT_GPIO_ACTIVE_LOW = 1 << 0, /* input is active low (else high) */ +}; + +/* This is the state of a GPIO pin as defined by the fdt */ +struct fdt_gpio_state { + const char *name; /* name of the fdt property defining this */ + uint gpio; /* GPIO number, or FDT_GPIO_NONE if none */ + u8 flags; /* FDT_GPIO_... flags */ +}; + +/* This tells us whether a fdt_gpio_state record is valid or not */ +#define fdt_gpio_isvalid(x) ((x)->gpio != FDT_GPIO_NONE) + /** * Find the next numbered alias for a peripheral. This is used to enumerate * all the peripherals of a certain type. @@ -227,3 +244,31 @@ int fdtdec_get_int_array(const void *blob, int node, const char *prop_name, * @return 1 if the properly is present; 0 if it isn't present */ int fdtdec_get_bool(const void *blob, int node, const char *prop_name); + +/** + * Decode a single GPIOs from an FDT. + * + * If the property is not found, then the GPIO structure will still be + * initialised, with gpio set to FDT_GPIO_NONE. This makes it easy to + * provide optional GPIOs. + * + * @param blob FDT blob to use + * @param node Node to look at + * @param prop_name Node property name + * @param gpio gpio elements to fill from FDT + * @return 0 if ok, -FDT_ERR_NOTFOUND if the property is missing. + */ +int fdtdec_decode_gpio(const void *blob, int node, const char *prop_name, + struct fdt_gpio_state *gpio); + +/** + * Set up a GPIO pin according to the provided gpio information. At present this + * just requests the GPIO. + * + * If the gpio is FDT_GPIO_NONE, no action is taken. This makes it easy to + * deal with optional GPIOs. + * + * @param gpio GPIO info to use for set up + * @return 0 if all ok or gpio was FDT_GPIO_NONE; -1 on error + */ +int fdtdec_setup_gpio(struct fdt_gpio_state *gpio); |