[PATCH v6 2/9] tty: n_gsm: add missing description to structs in gsmmux.h

D. Starke
2023-08-17T09:33:57Z

Currently, all available structure fields in gsmmux.h except those
for gsm_config are commented. Furthermore, no kernel doc comments are used.

Fix this by adding appropriate comments to the not commented fields of
gsm_config. Convert the comments of the other structs to kernel doc format.

Note that 'mru' and 'mtu' refer to the size without basic/advanced option
mode header and byte stuffing as defined in the standard in chapter 5.7.2.

Link: https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=1516
Signed-off-by: Daniel Starke <daniel.starke@siemens.com>
---
include/uapi/linux/gsmmux.h | 104 +++++++++++++++++++++++++++++-------
1 file changed, 84 insertions(+), 20 deletions(-)

v5 -> v6:
No changes.

Link: https://lore.kernel.org/all/20230517155704.5701-2-daniel.starke@siemens.com/

diff --git a/include/uapi/linux/gsmmux.h b/include/uapi/linux/gsmmux.h
index e56e2d7ea6eb..3bd6f03a8293 100644
--- a/include/uapi/linux/gsmmux.h
+++ b/include/uapi/linux/gsmmux.h
@@ -18,6 +18,28 @@
*/
#define GSM_FL_RESTART _BITUL(0)

+/**
+ * struct gsm_config - n_gsm basic configuration parameters
+ *
+ * This structure is used in combination with GSMIOC_GETCONF and GSMIOC_SETCONF
+ * to retrieve and set the basic parameters of an n_gsm ldisc.
+ * struct gsm_config_ext can be used to configure extended ldisc parameters.
+ *
+ * All timers are in units of 1/100th of a second.
+ *
+ * @adaption: Convergence layer type
+ * @encapsulation: Framing (0 = basic option, 1 = advanced option)
+ * @initiator: Initiator or responder
+ * @t1: Acknowledgment timer
+ * @t2: Response timer for multiplexer control channel
+ * @t3: Response timer for wake-up procedure
+ * @n2: Maximum number of retransmissions
+ * @mru: Maximum incoming frame payload size
+ * @mtu: Maximum outgoing frame payload size
+ * @k: Window size
+ * @i: Frame type (1 = UIH, 2 = UI)
+ * @unused: Can not be used
+ */
struct gsm_config
{
unsigned int adaption;
@@ -31,18 +53,32 @@ struct gsm_config
unsigned int mtu;
unsigned int k;
unsigned int i;
- unsigned int unused[8]; /* Can not be used */
+ unsigned int unused[8];
};

#define GSMIOC_GETCONF _IOR('G', 0, struct gsm_config)
#define GSMIOC_SETCONF _IOW('G', 1, struct gsm_config)

+/**
+ * struct gsm_netconfig - n_gsm network configuration parameters
+ *
+ * This structure is used in combination with GSMIOC_ENABLE_NET and
+ * GSMIOC_DISABLE_NET to enable or disable a network data connection
+ * over a mux virtual tty channel. This is for modems that support
+ * data connections with raw IP frames instead of PPP.
+ *
+ * @adaption: Adaption to use in network mode.
+ * @protocol: Protocol to use - only ETH_P_IP supported.
+ * @unused2: Can not be used.
+ * @if_name: Interface name format string.
+ * @unused: Can not be used.
+ */
struct gsm_netconfig {
- unsigned int adaption; /* Adaption to use in network mode */
- unsigned short protocol;/* Protocol to use - only ETH_P_IP supported */
- unsigned short unused2; /* Can not be used */
- char if_name[IFNAMSIZ]; /* interface name format string */
- __u8 unused[28]; /* Can not be used */
+ unsigned int adaption;
+ unsigned short protocol;
+ unsigned short unused2;
+ char if_name[IFNAMSIZ];
+ __u8 unused[28];
};

#define GSMIOC_ENABLE_NET _IOW('G', 2, struct gsm_netconfig)
@@ -51,27 +87,55 @@ struct gsm_netconfig {
/* get the base tty number for a configured gsmmux tty */
#define GSMIOC_GETFIRST _IOR('G', 4, __u32)

+/**
+ * struct gsm_config_ext - n_gsm extended configuration parameters
+ *
+ * This structure is used in combination with GSMIOC_GETCONF_EXT and
+ * GSMIOC_SETCONF_EXT to retrieve and set the extended parameters of an
+ * n_gsm ldisc.
+ *
+ * All timers are in units of 1/100th of a second.
+ *
+ * @keep_alive: Control channel keep-alive in 1/100th of a second (0 to disable).
+ * @wait_config: Wait for DLCI config before opening virtual link?
+ * @reserved: For future use, must be initialized to zero.
+ */
struct gsm_config_ext {
- __u32 keep_alive; /* Control channel keep-alive in 1/100th of a
- * second (0 to disable)
- */
- __u32 wait_config; /* Wait for DLCI config before opening virtual link? */
- __u32 reserved[6]; /* For future use, must be initialized to zero */
+ __u32 keep_alive;
+ __u32 wait_config;
+ __u32 reserved[6];
};

#define GSMIOC_GETCONF_EXT _IOR('G', 5, struct gsm_config_ext)
#define GSMIOC_SETCONF_EXT _IOW('G', 6, struct gsm_config_ext)

-/* Set channel accordingly before calling GSMIOC_GETCONF_DLCI. */
+/**
+ * struct gsm_dlci_config - n_gsm channel configuration parameters
+ *
+ * This structure is used in combination with GSMIOC_GETCONF_DLCI and
+ * GSMIOC_SETCONF_DLCI to retrieve and set the channel specific parameters
+ * of an n_gsm ldisc.
+ *
+ * Set the channel accordingly before calling GSMIOC_GETCONF_DLCI.
+ *
+ * @channel: DLCI (0 for the associated DLCI).
+ * @adaption: Convergence layer type.
+ * @mtu: Maximum transfer unit.
+ * @priority: Priority (0 for default value).
+ * @i: Frame type (1 = UIH, 2 = UI).
+ * @k: Window size (0 for default value).
+ * @flags: DLCI specific flags.
+ * @reserved: For future use, must be initialized to zero.
+ */
struct gsm_dlci_config {
- __u32 channel; /* DLCI (0 for the associated DLCI) */
- __u32 adaption; /* Convergence layer type */
- __u32 mtu; /* Maximum transfer unit */
- __u32 priority; /* Priority (0 for default value) */
- __u32 i; /* Frame type (1 = UIH, 2 = UI) */
- __u32 k; /* Window size (0 for default value) */
- __u32 flags; /* DLCI specific flags. */
- __u32 reserved[7]; /* For future use, must be initialized to zero */
+ __u32 channel;
+ __u32 adaption;
+ __u32 mtu;
+ __u32 priority;
+ __u32 i;
+ __u32 k;
+ __u32 flags;
+ __u32 reserved[7];
};

#define GSMIOC_GETCONF_DLCI _IOWR('G', 7, struct gsm_dlci_config)
--
2.34.1