diff options
Diffstat (limited to 'include/fdtdec.h')
| -rw-r--r-- | include/fdtdec.h | 197 |
1 files changed, 191 insertions, 6 deletions
diff --git a/include/fdtdec.h b/include/fdtdec.h index d871cdd1c1..171c628485 100644 --- a/include/fdtdec.h +++ b/include/fdtdec.h @@ -57,10 +57,30 @@ struct fdt_memory { */ enum fdt_compat_id { COMPAT_UNKNOWN, + COMPAT_NVIDIA_TEGRA20_USB, /* Tegra2 USB port */ + COMPAT_NVIDIA_TEGRA20_I2C, /* Tegra2 i2c */ + COMPAT_NVIDIA_TEGRA20_DVC, /* Tegra2 dvc (really just i2c) */ 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. @@ -82,6 +102,21 @@ int fdtdec_next_alias(const void *blob, const char *name, enum fdt_compat_id id, int *upto); /** + * Find the next compatible node for a peripheral. + * + * Do the first call with node = 0. This function will return a pointer to + * the next compatible node. Next time you call this function, pass the + * value returned, and the next node will be provided. + * + * @param blob FDT blob to use + * @param node Start node for search + * @param id Compatible ID to look for (enum fdt_compat_id) + * @return offset of next compatible node, or -FDT_ERR_NOTFOUND if no more + */ +int fdtdec_next_compatible(const void *blob, int node, + enum fdt_compat_id id); + +/** * Look up an address property in a node and return it as an address. * The property must hold either one address with no trailing data or * one address with a length. This is only tested on 32-bit machines. @@ -112,17 +147,167 @@ s32 fdtdec_get_int(const void *blob, int node, const char *prop_name, * Checks whether a node is enabled. * This looks for a 'status' property. If this exists, then returns 1 if * the status is 'ok' and 0 otherwise. If there is no status property, - * it returns the default value. + * it returns 1 on the assumption that anything mentioned should be enabled + * by default. * * @param blob FDT blob * @param node node to examine - * @param default_val default value to return if no 'status' property exists - * @return integer value 0/1, if found, or default_val if not + * @return integer value 0 (not enabled) or 1 (enabled) */ -int fdtdec_get_is_enabled(const void *blob, int node, int default_val); +int fdtdec_get_is_enabled(const void *blob, int node); /** - * Checks whether we have a valid fdt available to control U-Boot, and panic - * if not. + * Make sure we have a valid fdt available to control U-Boot. + * + * If not, a message is printed to the console if the console is ready. + * + * @return 0 if all ok, -1 if not + */ +int fdtdec_prepare_fdt(void); + +/** + * Checks that we have a valid fdt available to control U-Boot. + + * However, if not then for the moment nothing is done, since this function + * is called too early to panic(). + * + * @returns 0 */ int fdtdec_check_fdt(void); + +/** + * Find the nodes for a peripheral and return a list of them in the correct + * order. This is used to enumerate all the peripherals of a certain type. + * + * To use this, optionally set up a /aliases node with alias properties for + * a peripheral. For example, for usb you could have: + * + * aliases { + * usb0 = "/ehci@c5008000"; + * usb1 = "/ehci@c5000000"; + * }; + * + * Pass "usb" as the name to this function and will return a list of two + * nodes offsets: /ehci@c5008000 and ehci@c5000000. + * + * All nodes returned will match the compatible ID, as it is assumed that + * all peripherals use the same driver. + * + * If no alias node is found, then the node list will be returned in the + * order found in the fdt. If the aliases mention a node which doesn't + * exist, then this will be ignored. If nodes are found with no aliases, + * they will be added in any order. + * + * If there is a gap in the aliases, then this function return a 0 node at + * that position. The return value will also count these gaps. + * + * This function checks node properties and will not return nodes which are + * marked disabled (status = "disabled"). + * + * @param blob FDT blob to use + * @param name Root name of alias to search for + * @param id Compatible ID to look for + * @param node_list Place to put list of found nodes + * @param maxcount Maximum number of nodes to find + * @return number of nodes found on success, FTD_ERR_... on error + */ +int fdtdec_find_aliases_for_id(const void *blob, const char *name, + enum fdt_compat_id id, int *node_list, int maxcount); + +/* + * This function is similar to fdtdec_find_aliases_for_id() except that it + * adds to the node_list that is passed in. Any 0 elements are considered + * available for allocation - others are considered already used and are + * skipped. + * + * You can use this by calling fdtdec_find_aliases_for_id() with an + * uninitialised array, then setting the elements that are returned to -1, + * say, then calling this function, perhaps with a different compat id. + * Any elements you get back that are >0 are new nodes added by the call + * to this function. + * + * Note that if you have some nodes with aliases and some without, you are + * sailing close to the wind. The call to fdtdec_find_aliases_for_id() with + * one compat_id may fill in positions for which you have aliases defined + * for another compat_id. When you later call *this* function with the second + * compat_id, the alias positions may already be used. A debug warning may + * be generated in this case, but it is safest to define aliases for all + * nodes when you care about the ordering. + */ +int fdtdec_add_aliases_for_id(const void *blob, const char *name, + enum fdt_compat_id id, int *node_list, int maxcount); + +/* + * Get the name for a compatible ID + * + * @param id Compatible ID to look for + * @return compatible string for that id + */ +const char *fdtdec_get_compatible(enum fdt_compat_id id); + +/* Look up a phandle and follow it to its node. Then return the offset + * of that node. + * + * @param blob FDT blob + * @param node node to examine + * @param prop_name name of property to find + * @return node offset if found, -ve error code on error + */ +int fdtdec_lookup_phandle(const void *blob, int node, const char *prop_name); + +/** + * Look up a property in a node and return its contents in an integer + * array of given length. The property must have at least enough data for + * the array (4*count bytes). It may have more, but this will be ignored. + * + * @param blob FDT blob + * @param node node to examine + * @param prop_name name of property to find + * @param array array to fill with data + * @param count number of array elements + * @return 0 if ok, or -FDT_ERR_NOTFOUND if the property is not found, + * or -FDT_ERR_BADLAYOUT if not enough data + */ +int fdtdec_get_int_array(const void *blob, int node, const char *prop_name, + u32 *array, int count); + +/** + * Look up a boolean property in a node and return it. + * + * A boolean properly is true if present in the device tree and false if not + * present, regardless of its value. + * + * @param blob FDT blob + * @param node node to examine + * @param prop_name name of property to find + * @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); |
