mainlining shenanigans
138f5dc61b
Before this patch, m25p80_read() supported few SPI protocols:
- regular SPI 1-1-1
- SPI Dual Output 1-1-2
- SPI Quad Output 1-1-4
On the other hand, m25p80_write() only supported SPI 1-1-1.
This patch updates both m25p80_read() and m25p80_write() functions to let
them support SPI 1-2-2 and SPI 1-4-4 protocols for Fast Read and Page
Program SPI commands.
It adopts a conservative approach to avoid regressions. Hence the new
implementations try to be as close as possible to the old implementations,
so the main differences are:
- the tx_nbits values now being set properly for the spi_transfer
structures carrying the (op code + address/dummy) bytes
- and the spi_transfer structure being split into 2 spi_transfer
structures when the numbers of I/O lines are different for op code and
for address/dummy byte transfers on the SPI bus.
Besides, the current spi-nor framework supports neither the SPI 2-2-2 nor
the SPI 4-4-4 protocols. So, for now, we don't need to update the
m25p80_{read|write}_reg() functions as SPI 1-1-1 is the only one possible
protocol.
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Reviewed-by: Marek Vasut <marek.vasut@gmail.com>
|
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.