Reviewing the ECSPI reset handling shows two issues:
1. For the enable/reset bit (MXC_CSPICTRL_EN) in the control reg
(ECSPIx_CONGREG) the i.MX6 technical reference manual states:
-- cut --
ECSPIx_CONREG[0]: EN: Writing zero to this bit disables the block
and resets the internal logic with the exception of the ECSPI_CONREG.
-- cut --
Note the exception mentioned: The CONREG itself isn't reset.
Fix this by manually writing the reset value 0 to the whole register.
This sets the EN bit to zero, too (i.e. includes the old
~MXC_CSPICTRL_EN).
2. We want to reset the whole SPI block here. So it makes no sense
to first read the old value of the CONREG and write it back, later.
This will give us the old (historic/random) value of the CONREG back.
And doesn't reset the CONREG.
To get a clean CONREG after the reset of the block, too, don't use
the old (historic/random) value of the CONREG while doing the reset.
And read the clean CONREG after the reset.
This was found while working on a SPI boot device where the i.MX6 boot
ROM has already initialized the SPI block. The initialization by the
boot ROM might be different to what the U-Boot driver wants to configure.
I.e. we need a clean reset of SPI block, including the CONREG.
Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com>
CC: Stefano Babic <sbabic@denx.de>
CC: Fabio Estevam <fabio.estevam@freescale.com>
Measuring the spi clock line on a scope shows a 'glitch' during the reset of the
spi.
Fix this by toggling only the MXC_CSPICTRL_EN bit, so that the clock line becomes
always stable.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Stefano Babic <sbabic@denx.de>
In decode_cs() function the polarity of the chip select must be taken into
account.
Also, for the case of low active chip select, the CS was activated too early.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Use calloc() instead of malloc() to allocate the mxc_spi_slave structure.
Clearing the memory is necessary since most of the time this gets done
super early in boot, but on warm reboots, and when SPI probing is done
long after the init stages it could actually pick up previously used memory,
and things like the chipselect polarity and other data end up being filled
with trash data if not explicitly set by the board files.
This solves a semi-random, almost unreproducable error whereby SPI devices
act very, very strangly on boot. Tested on Efika MX over several years..
Signed-off-by: Matt Sealey <matt@genesi-usa.com>
Acked-by: Stefano Babic <sbabic@denx.de>
Since the input frequency of the API is a maximum that should not be exceeded in
order for the devices to operate properly, the SPI clock divider should be
rounded up, not truncated.
Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Stefano Babic <sbabic@denx.de>
Acked-by: Stefano Babic <sbabic@denx.de>
Move (E)CSPI register declarations into the imx-regs.h files for each supported CPU
Introduce two new macros to control conditional setup
MXC_CSPI - Used for processors with the Configurable Serial Peripheral Interface (MX3x)
MXC_ECSPI - For processors with Enhanced Configurable... (MX5x, MX6x)
Signed-off-by: Eric Nelson <eric.nelson@boundarydevices.com>
Acked-by: Dirk Behme <dirk.behme@de.bosch.com>
Acked-by: Stefano Babic <sbabic@denx.de>
Acked-by: Jason Liu <jason.hui@linaro.org>
Tested-by: Jason Liu <jason.hui@linaro.org>
IMX processors has a slightly different interface
to access GPIOs and do not make use of the provided GPIO
framework. The patch substitutes mxc_ specific
functions and make use of the API in asm/gpio.h
Signed-off-by: Stefano Babic <sbabic@denx.de>
As exception among the i.MX processors, the i.MX31 has headers
without general names (mx31-regs.h, mx31.h instead of imx-regs.h and
clock.h). This requires several nasty #ifdef in the drivers to
include the correct header. The patch cleans up the driver and
renames the header files as for the other i.MX processors.
Signed-off-by: Stefano Babic <sbabic@denx.de>
This patch cleans driver code replacing all accesses
to registers with fixed offsets with a corresponding
structure.
Signed-off-by: Stefano Babic <sbabic@denx.de>
The MXC SPI driver didn't calculate the SPI clock up to
now and just used highest possible divider 512 for DATA
RATE in the control register. This results in very low
transfer rates.
The patch adds code to calculate and setup the SPI clock
frequency for transfers.
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Signed-off-by: Stefano Babic <sbabic@denx.de>
We need to shift only one time in each cycle in the swapping loop
for unaligned tx case. Currently two byte shift operations are
performed in each loop cycle causing zero gaps in the transmited
data, so not all data scheduled for transmition is actually
transmited.
The proper swapping in unaligned rx case is missing, so add it
as we need to put the received data into the rx buffer in the
correct byte order.
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Tested-by: Stefano Babic <sbabic@denx.de>
The actual SPI driver for i.MX31 and i.MX51 controller
use a wrong byte ordering, because it is supposed
to work only with Freescale's devices, as the Power
Controllers (PMIC). The driver is not suitable for
general purposes, because the buffers passed to spi_xfer
must be 32-bit aligned, as it is used mainly to send
integer to PMIC devices.
The patch drops any kind of limitation and makes the
driver useful with devices controlled sending commands
composed by single bytes (or by a odd number of bytes), such as
spi flash, sensor, etc.
Because the byte ordering is changed,
any current driver using this controller must be adapted, too.
Signed-off-by: Stefano Babic <sbabic@denx.de>
The handling of the SPI_CPOL bit inside the SPI
driver was wrong. As reported by the manual,
the meaning of the SSPOL inside the
configuration register is the same as reported
by SPI specification (0 if low in idle, 1 is high
on idle). The driver inverts this logic.
Because this patch sets the logic as specified, it is required
to clear the CPOL bit in the configuration file to adapt
to the correct logic.
Signed-off-by: Stefano Babic <sbabic@denx.de>
Signed-off-by: David Jander <david.jander@protonic.nl>
The patch adds support for setting gpios to the
MX51 processor and change name to the corresponding
functions for MX31. In this way, it is possible to get rid
of nasty #ifdef switches related to the processor type.
Signed-off-by: Stefano Babic <sbabic@denx.de>
Commit f9b6a1575d, "i.MX31: fix SPI
driver for shorter than 32 bit" broke 32 bit transfers. This patch
makes single 32 bit transfer work again.
Transfer lengths that are known not to work will abort and print
an error message.
Tested on i.MX31 Litekit and i.MX31 PDK using 32 bit transfers to
the MC13783/ATLAS chip (using the 'date' command).
Signed-off-by: Magnus Lilja <lilja.magnus@gmail.com>
Some SPI devices have special requirements on chip-select handling.
With this patch we can use a GPIO as a chip-select and strictly follow
the SPI_XFER_BEGIN and SPI_XFER_END flags.
Signed-off-by: Guennadi Liakhovetski <lg@denx.de>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Fix setting the SPI Control register, 8 and 16-bit transfers
and a wrong pointer in the free routine in the mxc_spi driver.
Signed-off-by: Guennadi Liakhovetski <lg@denx.de>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
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 commit gets rid of a huge amount of silly white-space issues.
Especially, all sequences of SPACEs followed by TAB characters get
removed (unless they appear in print statements).
Also remove all embedded "vim:" and "vi:" statements which hide
indentation problems.
Signed-off-by: Wolfgang Denk <wd@denx.de>
This is an SPI driver for i.MX and MXC based SoCs from Freescale. So far
only implemented and tested on i.MX31, can with a modified register layout
and definitions be used for i.MX27, I think, MXC CPUs have similar SPI
controllers too.
Signed-off-by: Guennadi Liakhovetski <lg@denx.de>
