Commit Graph

12 Commits

Author SHA1 Message Date
Gabor Juhos 7410e84858 spi/ath79: add shutdown handler
The SPI controller of the AR7xxx/AR9xxx SoCs
have a special mode which allows the SoC to
directly read data from SPI flash chips. In
this mode, the content of the SPI flash chip
can be accessed via a memory mapped region.

During early init time, the kernel expects
that the flash chip is accessible through
that memory region because it reads board
specific values (e.g. MAC address, WiFi
calibration data) from the flash on various
boards.

This is working if the kernel is loaded
directly by the bootloader because that
leaves the SPI controller in the special
mode. However it is not working in a kexec'd
kernel because the SPI driver does not restore
the special mode during shutdown.

The patch adds a shutdown handler to fix this
issue.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2013-02-06 10:41:12 +00:00
Gabor Juhos c4a31f4300 spi/ath79: avoid multiple initialization of the SPI controller
Currently we are initializing the SPI controller in
the chip select line function, and that function is
called once for each SPI device on the bus. If a
board has multiple SPI devices, the controller will
be initialized multiple times.

Introduce ath79_spi_{en,dis}able helper functions,
and call those from probe/response in order to avoid
the mutliple initialization of the controller.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2013-02-05 12:59:47 +00:00
Gabor Juhos 95d79419fe spi/ath79: use gpio_request_one
Use gpio_request_one() instead of multiple gpiolib calls.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2013-02-05 12:58:55 +00:00
Gabor Juhos f1e8fc9898 spi/ath79: remove superfluous chip select code
The spi_bitbang driver calls the chipselect function
of the driver from spi_bitbang_setup in order to
deselect the given SPI chip, so we don't have to
initialize the CS line here.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2013-02-05 12:58:18 +00:00
Gabor Juhos 72611db0ee spi/ath79: add missing HIGH->LOW SCK transition
The 'ath79_spi_txrx_mode0' function does not
set the SCK signal to LOW at the end of a word
transfer. This causes communications errors with
certain devices (e.g. the PCF2123 RTC chip).

The patch ensures that the SCK signal will be LOW.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2013-02-05 12:57:45 +00:00
Gabor Juhos 440114fdb1 spi/ath79: add delay between SCK changes
The driver uses the "as fast as it can" approach
to drive the SCK signal. However this does not
work with certain low speed SPI chips (e.g. the
PCF2123 RTC chip).

The patch adds per-bit slowdowns in order to be
able to use the driver with such chips as well.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2013-02-05 12:57:02 +00:00
Grant Likely fd4a319bc9 spi: Remove HOTPLUG section attributes
CONFIG_HOTPLUG is going away as an option.  As result the __dev*
markings will be going away.

Remove use of __devinit, __devexit_p, __devinitdata, __devinitconst,
and __devexit.

Bill Pemberton has done most of the legwork on this series. I've used
his script to purge the attributes from the drivers/gpio tree.

Reported-by: Bill Pemberton <wfp5p@virginia.edu>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2012-12-07 17:06:43 +00:00
Grant Likely 1e8a52e18c spi: By default setup spi_masters with 1 chipselect and dynamics bus number
Trivial simplification.  Instead of requiring spi master drivers to
always set the bus number (even when a dynamic number is desired),
this patch modifies spi_alloc_master() to initialize num_chipselect to
1 (because there will always be at least one CS) and bus_num to -1 for
dynamic allocation.  This simplifies the code needed to be written for
drivers.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2012-05-19 23:42:08 -06:00
Gabor Juhos 807cc4b120 spi/ath79: fix compile error due to missing include
Whithout including 'linux/module.h' spi-ath79 driver fails to compile
with the these errors:

drivers/spi/spi-ath79.c:273:12: error: 'THIS_MODULE' undeclared here (not in a function)
drivers/spi/spi-ath79.c:278:20: error: expected declaration specifiers or '...' before string constant
drivers/spi/spi-ath79.c:278:1: warning: data definition has no type or storage class
drivers/spi/spi-ath79.c:278:1: warning: type defaults to 'int' in declaration of 'MODULE_DESCRIPTION'
drivers/spi/spi-ath79.c:278:20: warning: function declaration isn't a prototype
drivers/spi/spi-ath79.c:279:15: error: expected declaration specifiers or '...' before string constant
drivers/spi/spi-ath79.c:279:1: warning: data definition has no type or storage class
drivers/spi/spi-ath79.c:279:1: warning: type defaults to 'int' in declaration of 'MODULE_AUTHOR'
drivers/spi/spi-ath79.c:279:15: warning: function declaration isn't a prototype
drivers/spi/spi-ath79.c:280:16: error: expected declaration specifiers or '...' before string constant
drivers/spi/spi-ath79.c:280:1: warning: data definition has no type or storage class
drivers/spi/spi-ath79.c:280:1: warning: type defaults to 'int' in declaration of 'MODULE_LICENSE'
drivers/spi/spi-ath79.c:280:16: warning: function declaration isn't a prototype
drivers/spi/spi-ath79.c:281:14: error: expected declaration specifiers or '...' before string constant
drivers/spi/spi-ath79.c:281:1: warning: data definition has no type or storage class
drivers/spi/spi-ath79.c:281:1: warning: type defaults to 'int' in declaration of 'MODULE_ALIAS'
drivers/spi/spi-ath79.c:281:14: warning: function declaration isn't a prototype

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2011-12-07 21:57:49 +01:00
Grant Likely 940ab88962 drivercore: Add helper macro for platform_driver boilerplate
For simple modules that contain a single platform_driver without any
additional setup code then ends up being a block of duplicated
boilerplate.  This patch adds a new macro, module_platform_driver(),
which replaces the module_init()/module_exit() registrations with
template functions.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Reviewed-by: Magnus Damm <magnus.damm@gmail.com>
Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
2011-10-25 00:35:47 +02:00
Joe Perches 8e2943c04c spi: Convert uses of struct resource * to resource_size(ptr)
Done via coccinelle scripts like:

@@
struct resource *ptr;
@@

- ptr->end - ptr->start + 1
+ resource_size(ptr)

and some grep and typing.

Mostly uncompiled, no cross-compilers.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2011-06-10 23:43:41 -06:00
Grant Likely ca632f5566 spi: reorganize drivers
Sort the SPI makefile and enforce the naming convention spi_*.c for
spi drivers.

This change also rolls the contents of atmel_spi.h into the .c file
since there is only one user of that particular include file.

v2: - Use 'spi-' prefix instead of 'spi_' to match what seems to be
      be the predominant pattern for subsystem prefixes.
    - Clean up filenames in Kconfig and header comment blocks

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
2011-06-06 01:16:30 -06:00