The comment before the transmission loop in conjunction with the
definition of SPI_TIMEOUT as 1000 implies that the loop is supposed to
have a timeout value of 1000 ms. But since there is no mdelay(1) or
similar in the loop body, the loop just runs 1000 times, without regard
for the time elapsed.
To correct this, use the standard get_timer functionality to properly
time out the loop after 1000 ms.
Signed-off-by: Mario Six <mario.six@gdsys.cc>
Acked-by: Jagan Teki <jagan@amarulasolutions.com>
Decreasing the bit length and increasing the write data pointer should
be done when there are more than 32 bit of data, not 16 bit.
This did not produce incorrect behavior, because the only time where the
two checks produce different outcomes is the case of 16 < bitlen < 32,
and in this case the subsequent transmission is the last one regardless,
hence the additional bit length decrease and write data pointer increase
has no effect anyway.
Still, the correct check is the check for "bitlen > 32", so correct this
behavior.
Signed-off-by: Mario Six <mario.six@gdsys.cc>
Acked-by: Jagan Teki <jagan@amarulasolutions.com>
Minize the time the adapter is disabled (via SPI_MODE_EN
clearing/setting) to just the character length setting, and only set up
the temporary data writing variable right before we need it, so there is
a more clear distinction between setting up the SPI adapter, and setting
up the data to be written.
Signed-off-by: Mario Six <mario.six@gdsys.cc>
Acked-by: Jagan Teki <jagan@amarulasolutions.com>
Instead of having a table right before the code implementing the length
setting for documentation, have inline comments for the if branches
actually implementing the length setting described table's entries
(which is readable thanks to the set_char_len function).
Signed-off-by: Mario Six <mario.six@gdsys.cc>
Acked-by: Jagan Teki <jagan@amarulasolutions.com>
The variable "char_size" holds the number of bits to be transferred in
the current loop iteration. A better name would be "xfer_bitlen", which
we rename this variable to.
Signed-off-by: Mario Six <mario.six@gdsys.cc>
Acked-by: Jagan Teki <jagan@amarulasolutions.com>
Introduce the to_prescale_mod and set_char_len inline functions to make
the code more readable.
Note that the added "if (bitlen > 16)" check does not change the
semantics of the current code, and hence only preserves the current
error (this will be fixed in a later patch in the series).
Signed-off-by: Mario Six <mario.six@gdsys.cc>
Acked-by: Jagan Teki <jagan@amarulasolutions.com>
The transmission loop starts with setting some variables, which are only
used inside the loop. Reduce the scope to the loop to make the
declaration and initialization of these variables coincide.
In the case of char_size this also always initializes the variable
immediately with the final value actually used in the loop (instead of
the placeholder value 32).
Signed-off-by: Mario Six <mario.six@gdsys.cc>
Acked-by: Jagan Teki <jagan@amarulasolutions.com>
We do nothing in the loop if the "not empty" event was not detected. To
simplify the logic, check if this is the case, and skip the execution of
the loop early to reduce the nesting level and flag checking.
Signed-off-by: Mario Six <mario.six@gdsys.cc>
Acked-by: Jagan Teki <jagan@amarulasolutions.com>
Get rid of the is_read variable, and just keep the state of the "not
empty" and "not full" events in two boolean variables within the loop
body.
Signed-off-by: Mario Six <mario.six@gdsys.cc>
Acked-by: Jagan Teki <jagan@amarulasolutions.com>
Instead of having a nested if block, just have two branches within the
overarching if block to eliminate one nesting level.
Signed-off-by: Mario Six <mario.six@gdsys.cc>
Acked-by: Jagan Teki <jagan@amarulasolutions.com>
Accesses to the register map are currently done by directly reading and
writing the structure.
Switch to the appropriate IO accessors instead.
Signed-off-by: Mario Six <mario.six@gdsys.cc>
Acked-by: Jagan Teki <jagan@amarulasolutions.com>
Replace pre-processor defines with proper enums, and use the BIT macro
where applicable.
Signed-off-by: Mario Six <mario.six@gdsys.cc>
Acked-by: Jagan Teki <jagan@amarulasolutions.com>
Replace the function name with a "%s" format string and the __func__
variable in debug statements (as proposed by checkpatch).
Signed-off-by: Mario Six <mario.six@gdsys.cc>
Acked-by: Jagan Teki <jagan@amarulasolutions.com>
There are three variables that have camel-case names, which is not the
preferred naming style.
Give those variables more compliant names instead.
Signed-off-by: Mario Six <mario.six@gdsys.cc>
Acked-by: Jagan Teki <jagan@amarulasolutions.com>
There are some comments on the same line as the code they document. Put
comments above the code lines they document, so the line length is not
unnecessarily increased.
Signed-off-by: Mario Six <mario.six@gdsys.cc>
Acked-by: Jagan Teki <jagan@amarulasolutions.com>
The function signatures in the driver are quite long as is. Use short
type names (uint etc.) to make them more readable.
Signed-off-by: Mario Six <mario.six@gdsys.cc>
Acked-by: Jagan Teki <jagan@amarulasolutions.com>
When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from. So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry. Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.
In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.
This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents. There's also a few places where I found we did not have a tag
and have introduced one.
Signed-off-by: Tom Rini <trini@konsulko.com>
Replace numerical bit shift with BIT macro
in mpc8xxx_spi
:%s/(1 << nr)/BIT(nr)/g
where nr = 0, 1, 2 .... 31
Reviewed-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Jagan Teki <jteki@openedev.com>
Rather than each driver having its own way to allocate a SPI slave,
use the new allocation function everywhere. This will make it easier
to extend the interface without breaking drivers.
Signed-off-by: Simon Glass <sjg@chromium.org>
The MPC8308RDB Reference Manual states that no bits in the SPMODE
register are allowed to change while the enable (EN) bit is set.
This driver changes the character length bits (LEN) while the enable
(EN) bit is set. Clearing the EN bit while changing the LEN bits makes
the driver work correctly on MPC8308RDB.
Signed-off-by: Ira W. Snyder <iws@ovro.caltech.edu>
Signed-off-by: Kim Phillips <kim.phillips@freescale.com>
As discussed on the list, move "arch/ppc" to "arch/powerpc" to
better match the Linux directory structure.
Please note that this patch also changes the "ppc" target in
MAKEALL to "powerpc" to match this new infrastructure. But "ppc"
is kept as an alias for now, to not break compatibility with
scripts using this name.
Signed-off-by: Stefan Roese <sr@denx.de>
Acked-by: Wolfgang Denk <wd@denx.de>
Acked-by: Detlev Zundel <dzu@denx.de>
Acked-by: Kim Phillips <kim.phillips@freescale.com>
Cc: Peter Tyser <ptyser@xes-inc.com>
Cc: Anatolij Gustschin <agust@denx.de>
This patch gets rid of the spi_chipsel table and adds a handful of new
functions that makes the SPI layer cleaner and more flexible.
Instead of the spi_chipsel table, each board that wants to use SPI
gets to implement three hooks:
* spi_cs_activate(): Activates the chipselect for a given slave
* spi_cs_deactivate(): Deactivates the chipselect for a given slave
* spi_cs_is_valid(): Determines if the given bus/chipselect
combination can be activated.
Not all drivers may need those extra functions however. If that's the
case, the board code may just leave them out (assuming they know what
the driver needs) or rely on the linker to strip them out (assuming
--gc-sections is being used.)
To set up communication parameters for a given slave, the driver needs
to call spi_setup_slave(). This returns a pointer to an opaque
spi_slave struct which must be passed as a parameter to subsequent SPI
calls. This struct can be freed by calling spi_free_slave(), but most
driver probably don't want to do this.
Before starting one or more SPI transfers, the driver must call
spi_claim_bus() to gain exclusive access to the SPI bus and initialize
the hardware. When all transfers are done, the driver must call
spi_release_bus() to make the bus available to others, and possibly
shut down the SPI controller hardware.
spi_xfer() behaves mostly the same as before, but it now takes a
spi_slave parameter instead of a spi_chipsel function pointer. It also
got a new parameter, flags, which is used to specify chip select
behaviour. This may be extended with other flags in the future.
This patch has been build-tested on all powerpc and arm boards
involved. I have not tested NIOS since I don't have a toolchain for it
installed, so I expect some breakage there even though I've tried
fixing up everything I could find by visual inspection.
I have run-time tested this on AVR32 ATNGW100 using the atmel_spi and
DataFlash drivers posted as a follow-up. I'd like some help testing
other boards that use the existing SPI API.
But most of all, I'd like some comments on the new API. Is this stuff
usable for everyone? If not, why?
Changed in v4:
- Build fixes for various boards, drivers and commands
- Provide common struct spi_slave definition that can be extended by
drivers
- Pass a struct spi_slave * to spi_cs_activate and spi_cs_deactivate
- Make default bus and mode build-time configurable
- Override default SPI bus ID and mode on mx32ads and imx31_litekit.
Changed in v3:
- Add opaque struct spi_slave for controller-specific data associated
with a slave.
- Add spi_claim_bus() and spi_release_bus()
- Add spi_free_slave()
- spi_setup() is now called spi_setup_slave() and returns a
struct spi_slave
- soft_spi now supports four SPI modes (CPOL|CPHA)
- Add bus parameter to spi_setup_slave()
- Convert the new i.MX32 SPI driver
- Convert the new MC13783 RTC driver
Changed in v2:
- Convert the mpc8xxx_spi driver and the mpc8349emds board to the
new API.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Tested-by: Guennadi Liakhovetski <lg@denx.de>
This driver should only compile if CONFIG_MPC8XXX_SPI is set
Signed-off-by: Ben Warren <biggerbadderben@gmail.com>
Signed-off-by: Kim Phillips <kim.phillips@freescale.com>
This patch adds support for the SPI controller found on Freescale PowerPC
processors such as the MCP834x family. Additionally, a new config option,
CONFIG_HARD_SPI, is added for general purpose SPI controller use.
Signed-off-by: Ben Warren <biggerbadderben@gmail.com>
Signed-off-by: Kim Phillips <kim.phillips@freescale.com>
