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spi: pxa2xx: Use inclusive language
Replace master/slave by host/peripheral language in the documentation. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20231208170436.3309648-2-andriy.shevchenko@linux.intel.com Signed-off-by: Mark Brown <broonie@kernel.org>
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Andy Shevchenko
Mark Brown
parent
88a50c1663
commit
c3aeaf2f0e
@ -3,13 +3,13 @@ PXA2xx SPI on SSP driver HOWTO
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==============================
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This a mini HOWTO on the pxa2xx_spi driver. The driver turns a PXA2xx
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synchronous serial port into an SPI master controller
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synchronous serial port into an SPI host controller
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(see Documentation/spi/spi-summary.rst). The driver has the following features
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- Support for any PXA2xx and compatible SSP.
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- SSP PIO and SSP DMA data transfers.
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- External and Internal (SSPFRM) chip selects.
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- Per slave device (chip) configuration.
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- Per peripheral device (chip) configuration.
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- Full suspend, freeze, resume support.
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The driver is built around a &struct spi_message FIFO serviced by kernel
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@ -17,10 +17,10 @@ thread. The kernel thread, spi_pump_messages(), drives message FIFO and
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is responsible for queuing SPI transactions and setting up and launching
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the DMA or interrupt driven transfers.
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Declaring PXA2xx Master Controllers
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-----------------------------------
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Typically, for a legacy platform, an SPI master is defined in the
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arch/.../mach-*/board-*.c as a "platform device". The master configuration
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Declaring PXA2xx host controllers
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---------------------------------
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Typically, for a legacy platform, an SPI host controller is defined in the
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arch/.../mach-*/board-*.c as a "platform device". The host controller configuration
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is passed to the driver via a table found in include/linux/spi/pxa2xx_spi.h::
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struct pxa2xx_spi_controller {
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@ -30,7 +30,7 @@ is passed to the driver via a table found in include/linux/spi/pxa2xx_spi.h::
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};
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The "pxa2xx_spi_controller.num_chipselect" field is used to determine the number of
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slave device (chips) attached to this SPI master.
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peripheral devices (chips) attached to this SPI host controller.
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The "pxa2xx_spi_controller.enable_dma" field informs the driver that SSP DMA should
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be used. This caused the driver to acquire two DMA channels: Rx channel and
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@ -40,8 +40,8 @@ See the "PXA2xx Developer Manual" section "DMA Controller".
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For the new platforms the description of the controller and peripheral devices
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comes from Device Tree or ACPI.
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NSSP MASTER SAMPLE
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------------------
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NSSP HOST SAMPLE
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----------------
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Below is a sample configuration using the PXA255 NSSP for a legacy platform::
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static struct resource pxa_spi_nssp_resources[] = {
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@ -57,7 +57,7 @@ Below is a sample configuration using the PXA255 NSSP for a legacy platform::
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},
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};
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static struct pxa2xx_spi_controller pxa_nssp_master_info = {
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static struct pxa2xx_spi_controller pxa_nssp_controller_info = {
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.num_chipselect = 1, /* Matches the number of chips attached to NSSP */
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.enable_dma = 1, /* Enables NSSP DMA */
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};
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@ -68,7 +68,7 @@ Below is a sample configuration using the PXA255 NSSP for a legacy platform::
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.resource = pxa_spi_nssp_resources,
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.num_resources = ARRAY_SIZE(pxa_spi_nssp_resources),
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.dev = {
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.platform_data = &pxa_nssp_master_info, /* Passed to driver */
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.platform_data = &pxa_nssp_controller_info, /* Passed to driver */
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},
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};
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@ -81,17 +81,17 @@ Below is a sample configuration using the PXA255 NSSP for a legacy platform::
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(void)platform_add_device(devices, ARRAY_SIZE(devices));
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}
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Declaring Slave Devices
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-----------------------
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Typically, for a legacy platform, each SPI slave (chip) is defined in the
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Declaring peripheral devices
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----------------------------
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Typically, for a legacy platform, each SPI peripheral device (chip) is defined in the
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arch/.../mach-*/board-*.c using the "spi_board_info" structure found in
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"linux/spi/spi.h". See "Documentation/spi/spi-summary.rst" for additional
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information.
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Each slave device attached to the PXA must provide slave specific configuration
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Each peripheral device (chip) attached to the PXA2xx must provide specific chip configuration
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information via the structure "pxa2xx_spi_chip" found in
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"include/linux/spi/pxa2xx_spi.h". The pxa2xx_spi master controller driver
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will uses the configuration whenever the driver communicates with the slave
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"include/linux/spi/pxa2xx_spi.h". The PXA2xx host controller driver will use
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the configuration whenever the driver communicates with the peripheral
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device. All fields are optional.
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::
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@ -123,7 +123,7 @@ dma_burst_size == 0.
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The "pxa2xx_spi_chip.timeout" fields is used to efficiently handle
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trailing bytes in the SSP receiver FIFO. The correct value for this field is
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dependent on the SPI bus speed ("spi_board_info.max_speed_hz") and the specific
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slave device. Please note that the PXA2xx SSP 1 does not support trailing byte
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peripheral device. Please note that the PXA2xx SSP 1 does not support trailing byte
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timeouts and must busy-wait any trailing bytes.
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NOTE: the SPI driver cannot control the chip select if SSPFRM is used, so the
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@ -132,8 +132,8 @@ asserted around the complete message. Use SSPFRM as a GPIO (through a descriptor
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to accommodate these chips.
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NSSP SLAVE SAMPLE
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-----------------
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NSSP PERIPHERAL SAMPLE
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----------------------
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For a legacy platform or in some other cases, the pxa2xx_spi_chip structure
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is passed to the pxa2xx_spi driver in the "spi_board_info.controller_data"
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field. Below is a sample configuration using the PXA255 NSSP.
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@ -161,16 +161,16 @@ field. Below is a sample configuration using the PXA255 NSSP.
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.bus_num = 2, /* Framework bus number */
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.chip_select = 0, /* Framework chip select */
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.platform_data = NULL; /* No spi_driver specific config */
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.controller_data = &cs8415a_chip_info, /* Master chip config */
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.irq = STREETRACER_APCI_IRQ, /* Slave device interrupt */
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.controller_data = &cs8415a_chip_info, /* Host controller config */
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.irq = STREETRACER_APCI_IRQ, /* Peripheral device interrupt */
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},
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{
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.modalias = "cs8405a", /* Name of spi_driver for this device */
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.max_speed_hz = 3686400, /* Run SSP as fast a possible */
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.bus_num = 2, /* Framework bus number */
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.chip_select = 1, /* Framework chip select */
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.controller_data = &cs8405a_chip_info, /* Master chip config */
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.irq = STREETRACER_APCI_IRQ, /* Slave device interrupt */
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.controller_data = &cs8405a_chip_info, /* Host controller config */
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.irq = STREETRACER_APCI_IRQ, /* Peripheral device interrupt */
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},
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};
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