This patch adds an API to automatically enable either hardware components with existing device drivers or i2c clients. All functions take a device tree path to find the hardware and will fix up the node status in the kernel device tree, if it's accessible.
Signed-off-by: Daniel Schultz <[email protected]> --- Changes: v2: Moved from standalone file to oftree.c Added of_device_is_available, if a driver is disabled Added of_property_read_u32 Removed Kconfig Added of_ prefix to function names Renamed of_autoenable_i2c_by_path to of_autoenable_i2c_by_component common/oftree.c | 92 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ include/of.h | 14 +++++++++ 2 files changed, 106 insertions(+) diff --git a/common/oftree.c b/common/oftree.c index 09a4455..3b77a7e 100644 --- a/common/oftree.c +++ b/common/oftree.c @@ -11,6 +11,7 @@ #include <getopt.h> #include <init.h> #include <boot.h> +#include <i2c/i2c.h> #define MAX_LEVEL 32 /* how deeply nested we will go */ @@ -260,3 +261,94 @@ struct fdt_header *of_get_fixed_tree(struct device_node *node) return fdt; } + +/** + * of_autoenable_device_by_path() - Autoenable a device by a device tree path + * @param path Device tree path up from the root to the device + * @return 0 on success, -enodev on failure. If no device found in the device + * tree. + * + * This function will search for a device and will enable it in the kernel + * device tree, if it exists and is loaded. + */ +int of_autoenable_device_by_path(char *path) +{ + struct device_d *device; + struct device_node *node; + int ret; + + node = of_find_node_by_name(NULL, path); + if (!node) + node = of_find_node_by_path(path); + + if (!node) + return -ENODEV; + + device = of_find_device_by_node(node); + if (!device) + if (!of_device_is_available(node)) + return -ENODEV; + + ret = of_register_set_status_fixup(path, 1); + if (!ret) + printf("autoenabled %s\n", node->name); + return ret; +} + +/** + * of_autoenable_i2c_by_component - Autoenable a i2c client by a device tree path + * @param path Device tree path up from the root to the i2c client + * @return 0 on success, -enodev on failure. If no i2c client found in the i2c + * device tree. + * + * This function will search for a i2c client, tries to write to the client and + * will enable it in the kernel device tree, if it exists and is accessible. + */ +int of_autoenable_i2c_by_component(char *path) +{ + struct device_node *node; + struct i2c_adapter *i2c_adapter; + struct i2c_msg msg; + char data[1] = {0x0}; + int ret; + uint32_t addr; + + if (!IS_ENABLED(CONFIG_I2C)) + return -ENODEV; + + node = of_find_node_by_name(NULL, path); + if (!node) + node = of_find_node_by_path(path); + if (!node) + return -ENODEV; + if (!node->parent) + return -ENODEV; + + ret = of_property_read_u32(node, "reg", &addr); + if (ret) + return -ENODEV; + + i2c_adapter = of_find_i2c_adapter_by_node(node->parent); + if (!i2c_adapter) + return -ENODEV; + + msg.buf = data; + msg.addr = addr; + msg.len = 1; + + /* Try to communicate with the i2c client */ + ret = i2c_transfer(i2c_adapter, &msg, 1); + if (ret == -EREMOTEIO) + return -ENODEV; + if (ret < 1) { + printf("failed to autoenable i2c device on address 0x%x with %i\n", + addr, ret); + return ret; + } + + ret = of_register_set_status_fixup(path, 1); + if (!ret) + printf("autoenabled i2c device %s\n", node->name); + + return ret; +} diff --git a/include/of.h b/include/of.h index 18a4232..9bdbbb5e 100644 --- a/include/of.h +++ b/include/of.h @@ -262,6 +262,8 @@ struct device_node *of_find_node_by_alias(struct device_node *root, const char *alias); struct device_node *of_find_node_by_path_or_alias(struct device_node *root, const char *str); +int of_autoenable_device_by_path(char *path); +int of_autoenable_i2c_by_component(char *path); #else static inline int of_parse_partitions(struct cdev *cdev, struct device_node *node) @@ -664,6 +666,18 @@ static inline struct device_node *of_find_node_by_path_or_alias( { return NULL; } + +static inline int of_autoenable_i2c_by_path(char *path) +{ + return -ENODEV; +} + +static inline int of_autoenable_i2c_by_component(char *path) +{ + return -ENODEV; +} + + #endif #define for_each_node_by_name(dn, name) \ -- 2.7.4 _______________________________________________ barebox mailing list [email protected] http://lists.infradead.org/mailman/listinfo/barebox
