1 -------------------------------------------------------------------------------
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8 This project is programmed using the Linux kernel coding style:
10 https://www.kernel.org/doc/html/latest/process/coding-style.html
12 Please use the same style for any code contributions, thanks!
18 - In order to contribute you should ideally clone the git repository and
19 let us know (preferably via IRC, or via the mailing list) from where to
20 pull/review your changes. You can use github.com, or any other public git
23 - Alternatively, patches can be sent to the development mailinglist at
24 sigrok-devel@lists.sourceforge.net (please subscribe to the list first).
26 https://lists.sourceforge.net/lists/listinfo/sigrok-devel
29 Adding a new hardware driver
30 ----------------------------
32 The simple, scripted way (recommended):
33 ---------------------------------------
35 Use the 'new-driver' script from the sigrok-util repo:
37 $ git clone git://sigrok.org/sigrok-util
38 $ cd sigrok-util/source
39 $ ./new-driver "Tondaj SL-814"
41 The example above generates a patch file against the current libsigrok
42 development git tree which adds a simple "stub" driver for your device
43 (the Tondaj SL-814 sound level meter in this case).
45 You can apply it like this:
48 $ git am 0001-tondaj-sl-814-Initial-driver-skeleton.patch
50 You can now edit the files in src/hardware/tondaj-sl-814 as needed
51 and implement your driver based on the skeleton files there. That means your
52 patch submission later will consist of at least two patches: the initial one
53 adding the skeleton driver, and one or more additional patches that actually
54 implement the respective driver code.
60 This is a rough overview of what you need to do in order to add a new driver
61 (using the Tondaj SL-814 device as example). It's basically what the
62 'new-driver' script (see above) does for you:
64 - Makefile.am: Add to src_libdrivers_la_SOURCES under the HW_TONDAJ_SL_814
66 - configure.ac: Add an SR_DRIVER() call.
67 - src/drivers.c: Add a tondaj_sl_814_driver_info entry in two places.
68 - src/hardware/tondaj-sl-814/ directory: Add api.c, protocol.c, protocol.h.
70 See existing drivers or the 'new-driver' output for the details.
76 - Don't do variable declarations in compound statements, only at the
77 beginning of a function.
79 - Generally avoid assigning values to variables at declaration time,
80 especially so for complex and/or run-time dependent values.
82 - Consistently use g_*malloc() / g_*malloc0(). Do not use standard
83 malloc()/calloc() if it can be avoided (sometimes other libs such
84 as libftdi can return malloc()'d memory, for example).
86 - Always properly match allocations with the proper *free() functions. If
87 glib's g_*malloc()/g_*malloc0() was used, use g_free() to free the
88 memory. Otherwise use standard free(). Never use the wrong function!
90 - We assume that "small" memory allocations (< 1MB) will always succeed.
91 Thus, it's fine to use g_malloc() or g_malloc0() for allocations of
92 simple/small structs and such (instead of using g_try_malloc()), and
93 there's no need to check the return value.
95 Do use g_try_malloc() or g_try_malloc0() for large (>= 1MB) allocations
96 and check the return value.
98 - You should never print any messages (neither to stdout nor stderr nor
99 elsewhere) "manually" via e.g. printf() or g_log() or similar functions.
100 Only sr_err()/sr_warn()/sr_info()/sr_dbg()/sr_spew() should be used.
102 - Use glib's gboolean / TRUE / FALSE for boolean types consistently.
103 Do not use <stdbool.h> and its true / false, and do not invent private
104 definitions for this either.
106 - Consistently use the same naming convention for #include guards in headers:
107 <PROJECTNAME>_<PATH_TO_FILE>_<FILE>
108 This ensures that all #include guards are always unique and consistent.
109 Example: LIBSIGROK_HARDWARE_MIC_985XX_PROTOCOL_H
111 - Consistently use the same naming convention for API functions:
112 <libprefix>_<groupname>_<action>().
115 sr_log_loglevel_set(), sr_log_loglevel_get(), sr_log_handler_set(),
116 sr_log_handler_set_default(), and so on.
118 sr_session_new(), sr_session_destroy(), sr_session_load(), and so on.
120 Getter/setter function names should usually end with "_get" or "_set".
121 Functions creating new "objects" should end with "_new".
122 Functions destroying "objects" should end with "_destroy".
123 Functions adding or removing items (e.g. from lists) should end with
124 either "_add" or "_remove".
125 Functions operating on all items from a list (not on only one of them),
126 should end with "_all", e.g. "_remove_all", "_get_all", and so on.
127 Use "_remove_all" in favor of "_clear" for consistency.
129 - All enums should generally use an explicit start number of 10000.
130 If there are multiple "categories" in the enum entries, each category
131 should be 10000 entries apart from the next one. The start of categories
132 are thus 10000, 20000, 30000, and so on.
134 Adding items to an enum MUST always append to a "category", never add
135 items in the middle of a category. The order of items MUST NOT be changed.
136 Any of the above would break the ABI.
138 The enum item 0 is special and is used as terminator in some lists, thus
139 enums should not use this for "valid" entries (and start at 10000 instead).
145 - Use the @ notation for all Doxygen comments (e.g. @param, not \param).
147 - Do not use the @brief tag, it's unnecessary as we use JAVADOC_AUTOBRIEF.
149 - Generally use the following item order in Doxygen comments:
150 - Brief function description (1 line), followed by an empty line.
151 - Optionally, a longer function description (and another empty line).
152 - The list of parameter descriptions (@param).
153 - The return value description (@return or @retval).
154 - An optional @since tag (only for public SR_API functions).
155 - An optional @private tag (for private SR_PRIV functions).
157 - In @param lines, the name of the parameter is followed by a space and
158 then a sentence describing the parameter (starts with a capital letter,
159 ends with a full stop).
161 - In Doxygen comments, put an empty line between the block of @param lines
162 and the final @return line. The @param lines themselves (if there is more
163 than one) are not separated by empty lines.
165 - Mark private functions (SR_PRIV) with /** @private */, so that Doxygen
166 doesn't include them in the output. Functions that are "static" anyway
167 don't need to be marked like this.
169 - Mark private variables/#defines with /** @cond PRIVATE */ and
170 /** @endcond */, so that Doxygen doesn't include them in the output.
171 Variables that are "static" don't need to be marked like this.
173 - Mark all public API functions (SR_API) with a @since tag which indicates
174 in which release the respective function was added (e.g. "@since 0.1.0").
176 If the function has existed before, but its API changed later, the @since
177 tag should mention only the release when the API last changed.
179 Example: The sr_foo() call was added in 0.1.0, but the API changed in
180 the later 0.2.0 release. The docs should read "@since 0.2.0" in that case.
182 Non-public functions (static ones, and those marked SR_PRIV) don't need
183 to have @since markers.
185 The @since tag should be the last one, i.e. it should come after @param,
186 @return, @see, and so on.
191 * Tell a hardware driver to scan for devices.
193 * In addition to the detection, the devices that are found are also
194 * initialized automatically. On some devices, this involves a firmware upload,
195 * or other such measures.
197 * The order in which the system is scanned for devices is not specified. The
198 * caller should not assume or rely on any specific order.
200 * Before calling sr_driver_scan(), the user must have previously initialized
201 * the driver by calling sr_driver_init().
203 * @param[in] driver The driver that should scan. Must be a pointer to one of
204 * the entries returned by sr_driver_list(). Must not be NULL.
205 * @param[in] options List of 'struct sr_hwopt' options to pass to the driver's
206 * scanner. Can be NULL/empty.
208 * @return A GSList * of 'struct sr_dev_inst', or NULL if no devices were
209 * found (or errors were encountered). This list must be freed by the
210 * caller using g_slist_free(), but without freeing the data pointed
217 * Query value of a configuration key at the given driver or device instance.
219 * @param[in] driver The sr_dev_driver struct to query. Must not be NULL.
220 * @param[in] sdi (optional) If the key is specific to a device, this must
221 * contain a pointer to the struct sr_dev_inst to be checked.
222 * Otherwise it must be NULL. If sdi is != NULL, sdi->priv must
224 * @param[in,out] data Pointer to a GVariant where the value will be stored.
225 * Must not be NULL. The caller is given ownership of the GVariant
226 * and must thus decrease the refcount after use. However if
227 * this function returns an error code, the field should be
228 * considered unused, and should not be unreferenced.
230 * @retval SR_OK Success.
231 * @retval SR_ERR Error.
232 * @retval SR_ERR_ARG The driver doesn't know that key, but this is not to be
233 * interpreted as an error by the caller; merely as an indication
234 * that it's not applicable.
244 You can run the libsigrok testsuite using:
254 http://sigrok.org/wiki/Developers/Release_process
256 for a list of items that need to be done when releasing a new tarball.