diff options
| author | Mark Brown <broonie@kernel.org> | 2026-08-06 19:13:17 +0100 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2026-08-06 19:13:17 +0100 |
| commit | a2d6aa3b84466b2b5bfb74e07eb5b0b308b7022d (patch) | |
| tree | 4f76ee256ba251888278a523ca578a7ab38910a5 /include | |
| parent | 362a11ef1beadbc301ea949b85748e6bd1e0f384 (diff) | |
| parent | 036d4b059be01eb67b65b03131855fc42153de6a (diff) | |
spi: add new_device/delete_device sysfs interface
Vishwaroop A <va@nvidia.com> says:
Add I2C-style new_device/delete_device sysfs attributes to SPI host
controllers, allowing userspace to instantiate and remove SPI devices
at runtime without device-tree changes.
Patch 1 adds the new_device/delete_device attributes and the supporting
infrastructure (userspace_clients list, manual sysfs group registration).
Patch 2 adds the ABI and user-facing documentation.
Link: https://lore.kernel.org/linux-spi/20260728191056.2337791-1-va@nvidia.com/ # v8
Link: https://lore.kernel.org/linux-spi/20260728030541.2279518-1-va@nvidia.com/ # v7
Link: https://lore.kernel.org/linux-spi/cover.1784000000.git.va@nvidia.com/ # v6
Link: https://lore.kernel.org/linux-spi/20260517201602.498135-1-va@nvidia.com/ # v5
Link: https://lore.kernel.org/linux-tegra/909f0c92-d110-4253-903e-5c81e21e12c9@nvidia.com/
Link: https://patch.msgid.link/20260803104614.2548375-1-va@nvidia.com
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/spi/spi.h | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index 4c285d3ede1d..88d17fce02dc 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -179,6 +179,8 @@ extern void spi_transfer_cs_change_delay_exec(struct spi_message *msg, * @num_tx_lanes: Number of transmit lanes wired up. * @rx_lane_map: Map of peripheral lanes (index) to controller lanes (value). * @num_rx_lanes: Number of receive lanes wired up. + * @userspace_node: entry on the parent controller's userspace_clients list + * when this device was instantiated via the sysfs new_device interface * * A @spi_device is used to interchange data between an SPI target device * (usually a discrete chip) and CPU memory. @@ -252,6 +254,10 @@ struct spi_device { u8 rx_lane_map[SPI_DEVICE_DATA_LANE_CNT_MAX]; u8 num_rx_lanes; +#if IS_ENABLED(CONFIG_SPI_DYNAMIC) + struct list_head userspace_node; +#endif + /* * Likely need more hooks for more protocol options affecting how * the controller talks to each chip, like: @@ -555,6 +561,11 @@ extern struct spi_device *devm_spi_new_ancillary_device(struct spi_device *spi, * @defer_optimize_message: set to true if controller cannot pre-optimize messages * and needs to defer the optimization step until the message is actually * being transferred + * @userspace_clients: list of SPI devices instantiated from userspace via + * the sysfs new_device interface; protected by @add_lock + * @userspace_registered: true once the new_device/delete_device sysfs + * group has been added by spi_register_controller(); used by + * spi_unregister_controller() to know whether to remove it * * Each SPI controller can communicate with one or more @spi_device * children. These make a small bus, sharing MOSI, MISO and SCK signals @@ -807,6 +818,13 @@ struct spi_controller { bool queue_empty; bool must_async; bool defer_optimize_message; + +#if IS_ENABLED(CONFIG_SPI_DYNAMIC) + /* List of userspace-instantiated devices; protected by @add_lock */ + struct list_head userspace_clients; + /* True after new_device/delete_device sysfs group is created */ + bool userspace_registered; +#endif }; static inline void *spi_controller_get_devdata(struct spi_controller *ctlr) |