@@ -3,13 +3,13 @@ PXA2xx SPI on SSP driver HOWTO
==============================
This a mini HOWTO on the pxa2xx_spi driver. The driver turns a PXA2xx
-synchronous serial port into an SPI master controller
+synchronous serial port into an SPI host controller
(see Documentation/spi/spi-summary.rst). The driver has the following features
- Support for any PXA2xx and compatible SSP.
- SSP PIO and SSP DMA data transfers.
- External and Internal (SSPFRM) chip selects.
-- Per slave device (chip) configuration.
+- Per peripheral device (chip) configuration.
- Full suspend, freeze, resume support.
The driver is built around a &struct spi_message FIFO serviced by kernel
@@ -17,10 +17,10 @@ thread. The kernel thread, spi_pump_messages(), drives message FIFO and
is responsible for queuing SPI transactions and setting up and launching
the DMA or interrupt driven transfers.
-Declaring PXA2xx Master Controllers
------------------------------------
-Typically, for a legacy platform, an SPI master is defined in the
-arch/.../mach-*/board-*.c as a "platform device". The master configuration
+Declaring PXA2xx host controllers
+---------------------------------
+Typically, for a legacy platform, an SPI host controller is defined in the
+arch/.../mach-*/board-*.c as a "platform device". The host controller configuration
is passed to the driver via a table found in include/linux/spi/pxa2xx_spi.h::
struct pxa2xx_spi_controller {
@@ -30,7 +30,7 @@ is passed to the driver via a table found in include/linux/spi/pxa2xx_spi.h::
};
The "pxa2xx_spi_controller.num_chipselect" field is used to determine the number of
-slave device (chips) attached to this SPI master.
+peripheral devices (chips) attached to this SPI host controller.
The "pxa2xx_spi_controller.enable_dma" field informs the driver that SSP DMA should
be used. This caused the driver to acquire two DMA channels: Rx channel and
@@ -40,8 +40,8 @@ See the "PXA2xx Developer Manual" section "DMA Controller".
For the new platforms the description of the controller and peripheral devices
comes from Device Tree or ACPI.
-NSSP MASTER SAMPLE
-------------------
+NSSP HOST SAMPLE
+----------------
Below is a sample configuration using the PXA255 NSSP for a legacy platform::
static struct resource pxa_spi_nssp_resources[] = {
@@ -57,7 +57,7 @@ Below is a sample configuration using the PXA255 NSSP for a legacy platform::
},
};
- static struct pxa2xx_spi_controller pxa_nssp_master_info = {
+ static struct pxa2xx_spi_controller pxa_nssp_controller_info = {
.num_chipselect = 1, /* Matches the number of chips attached to NSSP */
.enable_dma = 1, /* Enables NSSP DMA */
};
@@ -68,7 +68,7 @@ Below is a sample configuration using the PXA255 NSSP for a legacy platform::
.resource = pxa_spi_nssp_resources,
.num_resources = ARRAY_SIZE(pxa_spi_nssp_resources),
.dev = {
- .platform_data = &pxa_nssp_master_info, /* Passed to driver */
+ .platform_data = &pxa_nssp_controller_info, /* Passed to driver */
},
};
@@ -81,17 +81,17 @@ Below is a sample configuration using the PXA255 NSSP for a legacy platform::
(void)platform_add_device(devices, ARRAY_SIZE(devices));
}
-Declaring Slave Devices
------------------------
-Typically, for a legacy platform, each SPI slave (chip) is defined in the
+Declaring peripheral devices
+----------------------------
+Typically, for a legacy platform, each SPI peripheral device (chip) is defined in the
arch/.../mach-*/board-*.c using the "spi_board_info" structure found in
"linux/spi/spi.h". See "Documentation/spi/spi-summary.rst" for additional
information.
-Each slave device attached to the PXA must provide slave specific configuration
+Each peripheral device (chip) attached to the PXA2xx must provide specific chip configuration
information via the structure "pxa2xx_spi_chip" found in
-"include/linux/spi/pxa2xx_spi.h". The pxa2xx_spi master controller driver
-will uses the configuration whenever the driver communicates with the slave
+"include/linux/spi/pxa2xx_spi.h". The PXA2xx host controller driver will use
+the configuration whenever the driver communicates with the peripheral
device. All fields are optional.
::
@@ -123,7 +123,7 @@ dma_burst_size == 0.
The "pxa2xx_spi_chip.timeout" fields is used to efficiently handle
trailing bytes in the SSP receiver FIFO. The correct value for this field is
dependent on the SPI bus speed ("spi_board_info.max_speed_hz") and the specific
-slave device. Please note that the PXA2xx SSP 1 does not support trailing byte
+peripheral device. Please note that the PXA2xx SSP 1 does not support trailing byte
timeouts and must busy-wait any trailing bytes.
NOTE: the SPI driver cannot control the chip select if SSPFRM is used, so the
@@ -132,8 +132,8 @@ asserted around the complete message. Use SSPFRM as a GPIO (through a descriptor
to accommodate these chips.
-NSSP SLAVE SAMPLE
------------------
+NSSP PERIPHERAL SAMPLE
+----------------------
For a legacy platform or in some other cases, the pxa2xx_spi_chip structure
is passed to the pxa2xx_spi driver in the "spi_board_info.controller_data"
field. Below is a sample configuration using the PXA255 NSSP.
@@ -161,16 +161,16 @@ field. Below is a sample configuration using the PXA255 NSSP.
.bus_num = 2, /* Framework bus number */
.chip_select = 0, /* Framework chip select */
.platform_data = NULL; /* No spi_driver specific config */
- .controller_data = &cs8415a_chip_info, /* Master chip config */
- .irq = STREETRACER_APCI_IRQ, /* Slave device interrupt */
+ .controller_data = &cs8415a_chip_info, /* Host controller config */
+ .irq = STREETRACER_APCI_IRQ, /* Peripheral device interrupt */
},
{
.modalias = "cs8405a", /* Name of spi_driver for this device */
.max_speed_hz = 3686400, /* Run SSP as fast a possible */
.bus_num = 2, /* Framework bus number */
.chip_select = 1, /* Framework chip select */
- .controller_data = &cs8405a_chip_info, /* Master chip config */
- .irq = STREETRACER_APCI_IRQ, /* Slave device interrupt */
+ .controller_data = &cs8405a_chip_info, /* Host controller config */
+ .irq = STREETRACER_APCI_IRQ, /* Peripheral device interrupt */
},
};
Replace master/slave by host/peripheral language in the documentation. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> --- Documentation/spi/pxa2xx.rst | 48 ++++++++++++++++++------------------ 1 file changed, 24 insertions(+), 24 deletions(-)