sensors: find i2c bus numbers by name

2 files changed, 46 insertions, 15 deletions

diff --git a/files/common/openwrt/sensors-read.lua b/files/common/openwrt/sensors-read.lua
index e441b9ea..b2fa6fd0 100755
--- a/files/common/openwrt/sensors-read.lua
+++ b/files/common/openwrt/sensors-read.lua
@@ -8,8 +8,8 @@ if not config then error(err) end
 local readings, err = sensors.read(config)
 if not readings then error(err) end
 for name, values in pairs(readings) do
-    print(name .. ":")
+    print(name .. " (" .. values['_kind_'] .. "):")
     for t, v in pairs(values) do
-        print(" * " .. t .. " = " .. v)
+        if t ~= '_kind_' then print(" * " .. t .. " = " .. v) end
     end
 end
diff --git a/files/common/openwrt/sensors.module_lua b/files/common/openwrt/sensors.module_lua
index dbae81ea..8a209dce 100644
--- a/files/common/openwrt/sensors.module_lua
+++ b/files/common/openwrt/sensors.module_lua
@@ -58,6 +58,25 @@ function _M.i2c_delete_device(bus, address)
     return _internal_.write_to_file(_M.i2c_bus_path(bus) .. "/delete_device", string.format("0x%02x", address))
 end
 
+function _M.i2c_get_bus_number_from_name(name)
+    local bus_paths, glob_result = glob.glob("/sys/bus/i2c/devices/i2c-*", 0)
+    if not bus_paths then
+        if glob_result == glob.GLOB_NOMATCH then return {} 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 _, bus_path in base.pairs(bus_paths) do
+        local num = string.match(bus_path, '/i2c%-(%d+)$')
+        if not num then return nil, "unable to parse bus number from path: " .. bus_path end
+
+        local contents, err = _internal_.read_from_file(bus_path .. "/name")
+        if contents ~= nil and contents:gsub("%s+", "") == name then return num end
+    end
+    return nil, "unable to find i2c bus with name: " .. name
+end
+
 function _M.i2c_get_mux_channels(parent, address)
     local channel_paths, glob_result = glob.glob(_M.i2c_device_path(parent, address) .. "/channel-*", 0)
     if not channel_paths then
@@ -83,29 +102,35 @@ function _M.i2c_get_mux_channels(parent, address)
 end
 
 
-function _M.i2c_add_devices_recursive(bus, devices)
+function _M.i2c_add_devices_recursive(bus_num, bus_name, devices)
+    if bus_num == nil then
+        local err
+        bus_num, err = _M.i2c_get_bus_number_from_name(bus_name)
+        if bus_num == nil then return nil, err end
+    end
+
     local num_sensors = 0
     local device
     for _, device in base.ipairs(devices) do
-        local ret, err = _M.i2c_add_device(bus, device.address, device.type)
+        local ret, err = _M.i2c_add_device(bus_num, device.address, device.type)
         if not ret then return nil, err end
 
         local setup_function = _internal_.setup[device.type]
         if setup_function ~= nil then
             time.nanosleep({tv_sec = 0, tv_nsec = 100000000})
-            local ret, err = setup_function(bus, device.address)
+            local ret, err = setup_function(bus_num, device.address)
             if ret == nil then return nil, err end
             num_sensors = num_sensors + ret
         end
 
         if device.channels then
             time.nanosleep({tv_sec = 0, tv_nsec = 100000000})
-            local mux_channels, err = _M.i2c_get_mux_channels(bus, device.address)
+            local mux_channels, err = _M.i2c_get_mux_channels(bus_num, device.address)
             if not mux_channels then return nil, error end
             local channel
             for _, channel in base.ipairs(device.channels) do
-                if not mux_channels[channel.number] then return nil, string.format("i2c-mux %s has no channel %d", _M.i2c_device_name(bus, device.address), channel.number) end
-                local tmp, err = _M.i2c_add_devices_recursive(mux_channels[channel.number], channel.devices)
+                if not mux_channels[channel.number] then return nil, string.format("i2c-mux %s has no channel %d", _M.i2c_device_name(bus_num, device.address), channel.number) end
+                local tmp, err = _M.i2c_add_devices_recursive(mux_channels[channel.number], nil, channel.devices)
                 if ret == nil then return nil, err end
                 num_sensors = num_sensors + tmp
             end
@@ -115,14 +140,20 @@ function _M.i2c_add_devices_recursive(bus, devices)
     return num_sensors
 end
 
-function _M.i2c_read_sensors_recursive(bus, devices)
+function _M.i2c_read_sensors_recursive(bus_num, bus_name, devices)
     local readings = {}
+    if bus_num == nil then
+        local err
+        bus_num, err = _M.i2c_get_bus_number_from_name(bus_name)
+        if bus_num == nil then return readings end
+    end
+
     local device
     for _, device in base.ipairs(devices) do
-        local name = device.name ~= nil and device.name or device.type .. "_" ..  _M.i2c_device_name(bus, device.address)
+        local name = device.name ~= nil and device.name or device.type .. "_" ..  _M.i2c_device_name(bus_num, device.address)
         local read_function = _internal_.read[device.type]
         if read_function ~= nil then
-            local values, kind = read_function(bus, device.address)
+            local values, kind = read_function(bus_num, device.address)
             if values ~= nil then
                 readings[name] = values
                 readings[name]['_kind_'] = kind
@@ -130,12 +161,12 @@ function _M.i2c_read_sensors_recursive(bus, devices)
         end
 
         if device.channels then
-            local mux_channels, err = _M.i2c_get_mux_channels(bus, device.address)
+            local mux_channels, err = _M.i2c_get_mux_channels(bus_num, device.address)
             if not mux_channels then return nil, error end
             local channel
             for _, channel in base.ipairs(device.channels) do
                 if mux_channels[channel.number] then
-                    local tmp, err = _M.i2c_read_sensors_recursive(mux_channels[channel.number], channel.devices)
+                    local tmp, err = _M.i2c_read_sensors_recursive(mux_channels[channel.number], nil, channel.devices)
                     if tmp ~= nil then for k,v in base.pairs(tmp) do readings[k] = v end end
                 end
             end
@@ -427,7 +458,7 @@ function _M.setup(config)
     if config.i2c then
         local i2c_bus
         for _, i2c_bus in base.ipairs(config.i2c) do
-            local tmp, err = _M.i2c_add_devices_recursive(i2c_bus.number, i2c_bus.devices)
+            local tmp, err = _M.i2c_add_devices_recursive(i2c_bus.number, i2c_bus.name, i2c_bus.devices)
             if tmp == nil then return nil, err end
             num_sensors = num_sensors + tmp
         end
@@ -451,7 +482,7 @@ function _M.read(config)
     if config.i2c then
         local i2c_bus
         for _, i2c_bus in base.ipairs(config.i2c) do
-            local tmp, err = _M.i2c_read_sensors_recursive(i2c_bus.number, i2c_bus.devices)
+            local tmp, err = _M.i2c_read_sensors_recursive(i2c_bus.number, i2c_bus.name, i2c_bus.devices)
             if tmp ~= nil then for k,v in base.pairs(tmp) do readings[k] = v end end
         end
     end