diff options
Diffstat (limited to 'Documentation/driver-api')
| -rw-r--r-- | Documentation/driver-api/driver-model/devres.rst | 4 | ||||
| -rw-r--r-- | Documentation/driver-api/gpio/legacy.rst | 5 | ||||
| -rw-r--r-- | Documentation/driver-api/phy/phy.rst | 25 | ||||
| -rw-r--r-- | Documentation/driver-api/serial/driver.rst | 3 | ||||
| -rw-r--r-- | Documentation/driver-api/serial/serial-rs485.rst | 56 |
5 files changed, 61 insertions, 32 deletions
diff --git a/Documentation/driver-api/driver-model/devres.rst b/Documentation/driver-api/driver-model/devres.rst index 8abf9dda3241..4249eb4239e0 100644 --- a/Documentation/driver-api/driver-model/devres.rst +++ b/Documentation/driver-api/driver-model/devres.rst @@ -365,6 +365,7 @@ MEM devm_kmemdup() devm_krealloc() devm_kstrdup() + devm_kstrdup_const() devm_kvasprintf() devm_kzalloc() @@ -395,6 +396,8 @@ PCI PHY devm_usb_get_phy() + devm_usb_get_phy_by_node() + devm_usb_get_phy_by_phandle() devm_usb_put_phy() PINCTRL @@ -447,6 +450,7 @@ SERDEV SLAVE DMA ENGINE devm_acpi_dma_controller_register() + devm_acpi_dma_controller_free() SPI devm_spi_alloc_master() diff --git a/Documentation/driver-api/gpio/legacy.rst b/Documentation/driver-api/gpio/legacy.rst index 9b12eeb89170..e17910cc3271 100644 --- a/Documentation/driver-api/gpio/legacy.rst +++ b/Documentation/driver-api/gpio/legacy.rst @@ -558,11 +558,6 @@ Platform Support To force-enable this framework, a platform's Kconfig will "select" GPIOLIB, else it is up to the user to configure support for GPIO. -It may also provide a custom value for ARCH_NR_GPIOS, so that it better -reflects the number of GPIOs in actual use on that platform, without -wasting static table space. (It should count both built-in/SoC GPIOs and -also ones on GPIO expanders. - If neither of these options are selected, the platform does not support GPIOs through GPIO-lib and the code cannot be enabled by the user. diff --git a/Documentation/driver-api/phy/phy.rst b/Documentation/driver-api/phy/phy.rst index 8fc1ce0bb905..8e8b3e8f9523 100644 --- a/Documentation/driver-api/phy/phy.rst +++ b/Documentation/driver-api/phy/phy.rst @@ -94,7 +94,8 @@ Inorder to dereference the private data (in phy_ops), the phy provider driver can use phy_set_drvdata() after creating the PHY and use phy_get_drvdata() in phy_ops to get back the private data. -4. Getting a reference to the PHY +Getting a reference to the PHY +============================== Before the controller can make use of the PHY, it has to get a reference to it. This framework provides the following APIs to get a reference to the PHY. @@ -130,6 +131,28 @@ the phy_init() and phy_exit() calls, and phy_power_on() and phy_power_off() calls are all NOP when applied to a NULL phy. The NULL phy is useful in devices for handling optional phy devices. +Order of API calls +================== + +The general order of calls should be:: + + [devm_][of_]phy_get() + phy_init() + phy_power_on() + [phy_set_mode[_ext]()] + ... + phy_power_off() + phy_exit() + [[of_]phy_put()] + +Some PHY drivers may not implement :c:func:`phy_init` or :c:func:`phy_power_on`, +but controllers should always call these functions to be compatible with other +PHYs. Some PHYs may require :c:func:`phy_set_mode <phy_set_mode_ext>`, while +others may use a default mode (typically configured via devicetree or other +firmware). For compatibility, you should always call this function if you know +what mode you will be using. Generally, this function should be called after +:c:func:`phy_power_on`, although some PHY drivers may allow it at any time. + Releasing a reference to the PHY ================================ diff --git a/Documentation/driver-api/serial/driver.rst b/Documentation/driver-api/serial/driver.rst index 23c6b956cd90..98d268555dcc 100644 --- a/Documentation/driver-api/serial/driver.rst +++ b/Documentation/driver-api/serial/driver.rst @@ -78,6 +78,9 @@ Other functions uart_get_lsr_info uart_handle_dcd_change uart_handle_cts_change uart_try_toggle_sysrq uart_get_console +.. kernel-doc:: include/linux/serial_core.h + :identifiers: uart_port_tx_limited uart_port_tx + Other notes ----------- diff --git a/Documentation/driver-api/serial/serial-rs485.rst b/Documentation/driver-api/serial/serial-rs485.rst index 6ebad75c74ed..dce061ef7647 100644 --- a/Documentation/driver-api/serial/serial-rs485.rst +++ b/Documentation/driver-api/serial/serial-rs485.rst @@ -29,23 +29,28 @@ RS485 Serial Communications 3. Data Structures Already Available in the Kernel ================================================== - The Linux kernel provides the serial_rs485 structure (see [1]) to handle - RS485 communications. This data structure is used to set and configure RS485 + The Linux kernel provides the struct serial_rs485 to handle RS485 + communications. This data structure is used to set and configure RS485 parameters in the platform data and in ioctls. - The device tree can also provide RS485 boot time parameters (see [2] - for bindings). The driver is in charge of filling this data structure from - the values given by the device tree. + The device tree can also provide RS485 boot time parameters + [#DT-bindings]_. The serial core fills the struct serial_rs485 from the + values given by the device tree when the driver calls + uart_get_rs485_mode(). Any driver for devices capable of working both as RS232 and RS485 should - implement the rs485_config callback and provide rs485_supported in the - uart_port structure. The serial core calls rs485_config to do the device - specific part in response to TIOCSRS485 ioctl (see below). The rs485_config - callback receives a pointer to a sanitizated serial_rs485 structure. The - serial_rs485 userspace provides is sanitized before calling rs485_config - using rs485_supported that indicates what RS485 features the driver supports - for the uart_port. TIOCGRS485 ioctl can be used to read back the - serial_rs485 structure matching to the current configuration. + implement the ``rs485_config`` callback and provide ``rs485_supported`` + in the ``struct uart_port``. The serial core calls ``rs485_config`` to do + the device specific part in response to TIOCSRS485 ioctl (see below). The + ``rs485_config`` callback receives a pointer to a sanitizated struct + serial_rs485. The struct serial_rs485 userspace provides is sanitized + before calling ``rs485_config`` using ``rs485_supported`` that indicates + what RS485 features the driver supports for the ``struct uart_port``. + TIOCGRS485 ioctl can be used to read back the struct serial_rs485 + matching to the current configuration. + +.. kernel-doc:: include/uapi/linux/serial.h + :identifiers: serial_rs485 uart_get_rs485_mode 4. Usage from user-level ======================== @@ -103,29 +108,28 @@ RS485 Serial Communications ======================== The Linux kernel provides addressing mode for multipoint RS-485 serial - communications line. The addressing mode is enabled with SER_RS485_ADDRB - flag in serial_rs485. Struct serial_rs485 has two additional flags and - fields for enabling receive and destination addresses. + communications line. The addressing mode is enabled with + ``SER_RS485_ADDRB`` flag in struct serial_rs485. The struct serial_rs485 + has two additional flags and fields for enabling receive and destination + addresses. Address mode flags: - - SER_RS485_ADDRB: Enabled addressing mode (sets also ADDRB in termios). - - SER_RS485_ADDR_RECV: Receive (filter) address enabled. - - SER_RS485_ADDR_DEST: Set destination address. + - ``SER_RS485_ADDRB``: Enabled addressing mode (sets also ADDRB in termios). + - ``SER_RS485_ADDR_RECV``: Receive (filter) address enabled. + - ``SER_RS485_ADDR_DEST``: Set destination address. - Address fields (enabled with corresponding SER_RS485_ADDR_* flag): - - addr_recv: Receive address. - - addr_dest: Destination address. + Address fields (enabled with corresponding ``SER_RS485_ADDR_*`` flag): + - ``addr_recv``: Receive address. + - ``addr_dest``: Destination address. Once a receive address is set, the communication can occur only with the particular device and other peers are filtered out. It is left up to the receiver side to enforce the filtering. Receive address will be cleared - if SER_RS485_ADDR_RECV is not set. + if ``SER_RS485_ADDR_RECV`` is not set. Note: not all devices supporting RS485 support multipoint addressing. 6. References ============= - [1] include/uapi/linux/serial.h - - [2] Documentation/devicetree/bindings/serial/rs485.txt +.. [#DT-bindings] Documentation/devicetree/bindings/serial/rs485.txt |