diff options
| author | Jan Dąbroś <jsd@semihalf.com> | 2016-03-11 00:38:00 +0100 |
|---|---|---|
| committer | Leif Lindholm <leif.lindholm@linaro.org> | 2016-07-11 18:28:26 +0100 |
| commit | 1ba493bfcc82032e66915a4da52f500f3cc4e1b6 (patch) | |
| tree | abcdec7c9b3f94bc80a059776770638d8039e948 /Documentation | |
| parent | 63af641436bde5924c20b3e2530e20ba70339512 (diff) | |
Drivers/Spi: Add Spi master driver
Spi master driver implements MARVELL_SPI_MASTER_PROTOCOL.
It configures and manages SPI controller.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jan Dabros <jsd@semihalf.com>
Signed-off-by: Marcin Wojtas <mw@semihalf.com>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/Marvell/Drivers/SpiDriver.txt | 116 | ||||
| -rw-r--r-- | Documentation/Marvell/PortingGuide/Spi.txt | 15 |
2 files changed, 131 insertions, 0 deletions
diff --git a/Documentation/Marvell/Drivers/SpiDriver.txt b/Documentation/Marvell/Drivers/SpiDriver.txt new file mode 100644 index 0000000..42b5e3c --- /dev/null +++ b/Documentation/Marvell/Drivers/SpiDriver.txt @@ -0,0 +1,116 @@ +1. Introduction
+---------------
+**SpiDxe** driver implements MARVELL_SPI_MASTER_PROTOCOL in order to manage SPI
+controller on Marvell A8k boards. It exposes below functionalities:
+ - create and setup SPI slaves
+ - raw transfer over SPI bus
+
+2. SpiDxe driver design
+-----------------------
+
+ 2.1 MARVELL_SPI_MASTER_PROTOCOL
+ -----------------------
+ First member of SPI_MASTER protocol is Init function, implemented for SPI
+ master controller initialization.
+
+ ->Init()
+
+ //
+ //Initializes the host controller to execute SPI commands.
+ //
+
+ param[IN] This Pointer to the MARVELL_SPI_MASTER_PROTOCOL instance
+
+ return EFI_SUCCESS Opcode initialization on the SPI host
+ controller completed.
+ return EFI_ACCESS_DENIED The SPI configuration interface is
+ locked.
+ return EFI_OUT_OF_RESOURCES Not enough resource available to
+ initialize the device.
+ return EFI_DEVICE_ERROR Device error, operation failed.
+
+ ********
+
+ SPI devices (slaves) do not support any kind of automatic discovery or
+ enumaration, so every device needs manual configuration, which may be done
+ with SetupDevice function.
+
+ ->SetupDevice()
+
+ //
+ //Allocate and zero all fields in the SPI_DEVICE struct. Set the chip
+ //select, max frequency and transfer mode supported by slave device.
+ //
+
+ param[IN] Cs Chip select ID of the slave chip.
+ param[IN] MaxFreq Maximum SCK rate in Hz.
+ param[IN] Mode Clock polarity and clock phase.
+
+ return *SPI_DEVICE Pointer to new allocated struct SPI_DEVICE.
+ return NULL NULL pointer if any eroor occured.
+
+ ********
+
+ Developers have to destroy all created SPI device structs (with FreeDevice
+ function) in order to prevent from memory leak.
+
+ ->FreeDevice()
+
+ //
+ //Free any memory associated with a SPI device.
+ //
+
+ param[in] SpiDev Pointer to the SPI_DEVICE struct.
+
+ return EFI_SUCCESS Memory fried succesfully.
+ return EFI_DEVICE_ERROR Device error, operation failed.
+
+ ********
+
+ Transfer function allows write/read raw bytes over SPI bus.
+
+ ->Transfer()
+
+ //
+ //Perform transfer over SPI bus
+ //
+ param[in] This Pointer to the MARVELL_SPI_MASTER_PROTOCOL
+ instance.
+ param[in] Slave Pointer to the SPI_DEVICE struct.
+ param[in] DataByteCount Number of bytes in the data portion of
+ the SPI cycle.
+ param[in] DataOut Pointer to caller-allocated buffer
+ containing the data to send.
+ param[out] DataIn Pointer to caller-allocated buffer
+ where received data will be placed.
+ param[in] Flag Flags which indicate state of CS line
+ during/after transfer (see file
+ Drivers/Spi/Devices/A8kSpiFlash.h)
+
+ return EFI_SUCCESS Memory fried succesfully.
+ return EFI_DEVICE_ERROR Device error, operation failed.
+
+ *********
+
+ When working with SPI devices it is often necessary to perform "command and
+ address" transactions. It may be done via ReadWrite function.
+
+ ->ReadWrite()
+
+ //
+ //Perform two steps transactions. First write Command, then read/write
+ //buffer
+ //
+
+ param[in] This Pointer to the MARVELL_SPI_MASTER_PROTOCOL
+ instance.
+ param[in] Slave Pointer to the SPI_DEVICE struct.
+ param[in] Cmd Pointer to caller-allocated buffer
+ containing the command to send.
+ param[in] CmdSize Size of command (in bytes).
+ param[in] DataOut Pointer to caller-allocated buffer
+ containing the data to send.
+ param[out] DataIn Pointer to caller-allocated buffer
+ where received data will be placed.
+ param[in] DataSize Number of bytes in the data portion of
+ the SPI cycle.
diff --git a/Documentation/Marvell/PortingGuide/Spi.txt b/Documentation/Marvell/PortingGuide/Spi.txt new file mode 100644 index 0000000..f1f36ad --- /dev/null +++ b/Documentation/Marvell/PortingGuide/Spi.txt @@ -0,0 +1,15 @@ +Spi driver configuration
+------------------------
+Following PCDs are available for configuration of spi driver:
+
+ gMarvellTokenSpaceGuid.PcdSpiClockFrequency
+
+Frequency (in Hz) of SPI clock
+
+ gMarvellTokenSpaceGuid.PcdSpiMaxFrequency
+
+Max SCLK line frequency (in Hz) (max transfer frequency)
+
+ gMarvellTokenSpaceGuid.PcdSpiDefaultMode
+
+default SCLK mode (see SPI_MODE enum in file OpenPlatformPkg/Drivers/Spi/MvSpi.h)
|