add some test script for sensors (WIP)

1 files changed, 75 insertions, 0 deletions

diff --git a/files/common/openwrt/sensors-init.lua b/files/common/openwrt/sensors-init.lua
new file mode 100755
index 00000000..f958dd2d
--- /dev/null
+++ b/files/common/openwrt/sensors-init.lua
@@ -0,0 +1,75 @@
+#!/usr/bin/lua
+
+cjson = require "cjson.safe"
+glob = require "posix.glob"
+time = require "posix.time"
+unistd = require "posix.unistd"
+
+-- ############# utils ###########
+
+function i2c_bus_path(bus)
+    return string.format("/sys/bus/i2c/devices/i2c-%d", bus)
+end
+
+function i2c_device_path(bus, address)
+    return string.format("/sys/bus/i2c/devices/%d-%04X", bus, address)
+end
+
+function i2c_add_device(bus, name, address)
+    local f, err = io.open(i2c_bus_path(bus) .. "/new_device", "w")
+    if not f then return nil, err end
+
+    ret, err = f:write(string.format("%s 0x%02X", name, address))
+    f:close()
+    return ret, err
+end
+
+function i2c_delete_device(bus, address)
+    local f, err = io.open(i2c_bus_path(bus) .. "/delete_device", "w")
+    if not f then return nil, err end
+
+    ret, err = f:write(string.format("0x%02X", address))
+    f:close()
+    return ret, err
+end
+
+function i2c_get_mux_channels(parent, address)
+    local channels = {}
+    local channel_paths, glob_result = glob.glob(i2c_device_path(parent, address) .. "/channel-*", 0)
+    if not channel_paths then
+        if glob_result == glob.GLOB_NOMATCH then return channels end
+        if glob_result == glob.GLOB_ABORTED then return nil, "glob(): aborted" end
+        if glob_result == glob.GLOB_NOSPACE then return nil, "glob(): no space" end
+        return nil, "glob(): unknown error"
+    end
+    for _, channel_path in pairs(channel_paths) do
+        local channel = string.match(channel_path, '/channel%-(%d+)$')
+        if not channel then return nil, "unable to parse channel number from path: " .. channel_path end
+
+        local bus_path, err = unistd.readlink(channel_path)
+        if not bus_path then return nil, err end
+        local bus = string.match(bus_path, '/i2c%-(%d+)$')
+        if not bus then return nil, "unable to parse bus number from path: " .. bus_path end
+
+        channels[channel] = bus
+    end
+    return channels
+end
+
+-- ############# main ###########
+
+-- assert(i2c_delete_device(0, 0x70))
+-- time.nanosleep({tv_sec = 0, tv_nsec = 100000000})
+assert(i2c_add_device(0, "pca9548", 0x70))
+local mux_channels, err = i2c_get_mux_channels(0, 0x70)
+if not mux_channels then error(err) end
+for ch, bus in pairs(mux_channels) do
+    print(string.format("mux channel %d -> %s", ch, i2c_bus_path(bus)))
+end
+
+-- i2c_add_device(0, "ds2482", 0x18)
+-- i2c_add_device(0, "ads1115", 0x48)
+-- i2c_add_device(0, "bme280", 0x76)
+-- i2c_add_device(0, "bmp280", 0x77)
+-- i2c_add_device(0, "am2315", 0x5c)
+-- i2c_add_device(0, "mcp3221", 0x4d)