According to NXP ESPI datasheet, the SPI clock rate is:
spi_clk = System_Clock / ( 2 * DIV16 * ( 1 + PM ) )
Where System_Clock is the platform clock divided by 2,
DIV16 may be 1 or 16, and PM is a 4 bits integer (0 to 15).
Isolating PM on the expression, we get:
PM = (System_Clock / ( 2 * DIV16 * spi_clk ) ) - 1
Where System_Clock = mpc8xxx_spi->spibrg / 2, spi_clk = hz,
and DIV16 = 1 or DIV16 = 16. So,
PM = (mpc8xxx_spi->spibrg / ( 4 * hz) ) - 1
or
PM = (mpc8xxx_spi->spibrg / ( 16 * 4 * hz) ) - 1
Current spi-fsl-espi driver can't configure the HW for all
supported clock rates. It filters out clock rates for PM = 0
and PM = 1.
This patch allows all range of supported clock rates to be
configured on the ESPI controller.
Signed-off-by: Paulo Zaneti <paulo.zaneti@datacom.ind.br>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
spin_lock is used to obtain the spinlock, so spin_unlock
has to be used here.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Currently the driver polls in the ISR for enough bytes in the RX FIFO.
An ISR should never do this.
Change it to read as much as possible whenever the ISR is called.
This also allows to significantly simplify the code.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
So far an interrupt is triggered whenever there's at least one byte
in the RX FIFO. This results in a unnecessarily high number of
interrupts.
Change this to generate an interrupt if
- RX FIFO is half full (except if all bytes to read fit into the
RX FIFO anyway)
- end of transfer has been reached
This way the number of interrupts can be significantly reduced.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Extend and improve transfer error handling
- in case of timeout report also number of remaining rx bytes
- in case of timeout return ETIMEDOUT instead of EMSGSIZE
- add sanity checks after all bytes have been sent / read:
- check that HW has flag SPIE_DON set
- check that RX / TX FIFO are empty
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
The ESPI spec mentions no requirement to turn off the ESPI unit prior
to changing the mode. Most likely the ESPI unit is only turned off to
clear the FIFO's as before this patch series single bytes could
remain in the TX FIFO after transfer end.
Therefore remove disabling / re-enabling the ESPI unit.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Now that we introduced element tx_len in struct mpc8xxx_spi let's
rename element len to rx_len as it actually is the number of bytes to
receive. In addition make it unsigned.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This change addresses two issues:
- If the TX FIFO is full the ISR polls until there's free space again.
An ISR should never wait for something.
- Currently the number of bytes to transfer is rounded up to the next
multiple of 4. For most transfers therefore few bytes remain in the
TX FIFO after end of transfer.
This would cause the next transfer to fail and as a workaround the
ESPI block is disabled / re-enabled in fsl_espi_change_mode.
This seems to clear the FIFO's (although it's not mentioned in the
spec).
With this change the TX FIFO is filled as much as possible initially
and whenever the ISR is called. Also the exact number of bytes is
transferred.
The spinlock protects against a potential race if the first interrupt
occurs whilst the TX FIFO is still being initially filled.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
SPI_QE_CPU_MODE doesn't exist for ESPI and is set by of_mpc8xxx_spi_probe
based on DT property "mode". This property is not defined for ESPI,
see Documentation/devicetree/bindings/spi/fsl-spi.txt.
So print an error message and bail out if SPI_QE_CPU_MODE is set.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Commit 5c0ba57744 ("spi: fsl-espi: avoid processing uninitalized
data on error") applied fine to stable but caused a merge conflict
on next. This patch fixes that.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
When we get a spurious interrupt in fsl_espi_irq, we end up
processing four uninitalized bytes of data, as shown in this
warning message:
drivers/spi/spi-fsl-espi.c: In function 'fsl_espi_irq':
drivers/spi/spi-fsl-espi.c:462:4: warning: 'rx_data' may be used uninitialized in this function [-Wmaybe-uninitialized]
This adds another check so we skip the data in this case.
Fixes: 6319a68011 ("spi/fsl-espi: avoid infinite loops on fsl_espi_cpu_irq()")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
The code in fsl_espi_tx_buf_lsb and parts of fsl_espi_setup_transfer
look very weird and don't reflect the ESPI spec.
ESPI stores values with <= 8 bit word size right justified as 8 bit
value and values with > 8 bit word size right justified as 16 bit
value. Therefore no such shifting is needed.
Only case MSB-first with 8 bit word size is correctly handled,
and most likely nobody ever used this driver with a different config.
On ESPI only the case LSB-first with word size > 8 bit needs a
special handling. In this case a little endian 16 bit value has
to be written to the TX FIFO what requires a byte swap as the
host system is big endian.
The same applies to reading from the RX FIFO.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
According to the ESPI spec MSB-first transfers are supported for
word size 8 and 16 only.
Check for this and reject MSB-first transfers with other word sizes.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
of_property_read_u32 is better here than generic of_get_property:
- implicit endianness conversion if needed
- implicit checking of size of property
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
A good practice is to prefix the names of functions by the name
of the subsystem.
The kthread worker API is a mix of classic kthreads and workqueues. Each
worker has a dedicated kthread. It runs a generic function that process
queued works. It is implemented as part of the kthread subsystem.
This patch renames the existing kthread worker API to use
the corresponding name from the workqueues API prefixed by
kthread_:
__init_kthread_worker() -> __kthread_init_worker()
init_kthread_worker() -> kthread_init_worker()
init_kthread_work() -> kthread_init_work()
insert_kthread_work() -> kthread_insert_work()
queue_kthread_work() -> kthread_queue_work()
flush_kthread_work() -> kthread_flush_work()
flush_kthread_worker() -> kthread_flush_worker()
Note that the names of DEFINE_KTHREAD_WORK*() macros stay
as they are. It is common that the "DEFINE_" prefix has
precedence over the subsystem names.
Note that INIT() macros and init() functions use different
naming scheme. There is no good solution. There are several
reasons for this solution:
+ "init" in the function names stands for the verb "initialize"
aka "initialize worker". While "INIT" in the macro names
stands for the noun "INITIALIZER" aka "worker initializer".
+ INIT() macros are used only in DEFINE() macros
+ init() functions are used close to the other kthread()
functions. It looks much better if all the functions
use the same scheme.
+ There will be also kthread_destroy_worker() that will
be used close to kthread_cancel_work(). It is related
to the init() function. Again it looks better if all
functions use the same naming scheme.
+ there are several precedents for such init() function
names, e.g. amd_iommu_init_device(), free_area_init_node(),
jump_label_init_type(), regmap_init_mmio_clk(),
+ It is not an argument but it was inconsistent even before.
[arnd@arndb.de: fix linux-next merge conflict]
Link: http://lkml.kernel.org/r/20160908135724.1311726-1-arnd@arndb.de
Link: http://lkml.kernel.org/r/1470754545-17632-3-git-send-email-pmladek@suse.com
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Borislav Petkov <bp@suse.de>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
To avoid warning when using i2c gpio expander change call to the
cansleep variant. There should be no issue with sleeping in the
drivers probe function.
Signed-off-by: Phil Reid <preid@electromag.com.au>
Signed-off-by: Mark Brown <broonie@kernel.org>
Kbuild test robot reports:
drivers/spi/spi-pxa2xx.c: In function ‘setup_cs’:
drivers/spi/spi-pxa2xx.c:1190:20: error: implicit declaration of function ‘desc_to_gpio’
...
Reason for this is the fact that those functions are declared in
linux/gpio/consumer.h which is not included in the driver. Fix this by
including it.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Fix to return error code -EINVAL if no CS GPIOs available
instead of 0, as done elsewhere in this function.
Fixes: f13d4e189d ("spi: imx: Gracefully handle NULL master->cs_gpios")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Acked-by: Marek Vasut <marex@denx.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
The driver uses custom chip_info coming from platform data for chip selects
implemented as GPIOs. If the system lacks board files setting up the
platform data, it is not possible to use GPIOs as chip selects.
This adds support for GPIO descriptors so that regardless of the underlying
firmware interface (DT, ACPI or platform data) the driver can request GPIOs
used as chip selects and configure them accordingly.
The custom chip_info GPIO support is still left there to make sure the
existing systems keep working as expected.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
It is possible that master->cs_gpios is NULL after spi_bitbang_start(),
this happens if the master has no CS GPIOs specified in DT. Check for
this case after spi_bitbang_start() to prevent NULL pointer dereference
in the subsequent for loop, which accesses the master->cs_gpios field.
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Martin Kaiser <martin@kaiser.cx>
Cc: Mark Brown <broonie@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
This spi driver uses the common spi-bcm-qspi driver and implements iProc
SoCs specific interrupt controller. The common driver now calls the SoC
handlers when present. Adding support for both muxed l1 and unmuxed interrupt
sources.
Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
Signed-off-by: Yendapally Reddy Dhananjaya Reddy <yendapally.reddy@broadcom.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
The return value of fsl_espi_probe (currently struct spi_master *)
is just used for checking whether an error occurred.
Change the return value type to int and simplify the code.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Fix to return a negative error code from the error handling
case instead of 0, as done elsewhere in this function.
Fixes: fa236a7ef2 ("spi: bcm-qspi: Add Broadcom MSPI driver")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
In case of error, the function kcalloc() returns NULL pointer
not ERR_PTR(). The IS_ERR() test in the return value check
should be replaced with NULL test.
Fixes: fa236a7ef2 ("spi: bcm-qspi: Add Broadcom MSPI driver")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
The two power management functions are define inside of an #ifdef
but referenced unconditionally, which is obviously broken when
CONFIG_PM_SLEEP is not set:
drivers/spi/spi-bcm-qspi.c:1300:13: error: 'bcm_qspi_suspend' undeclared here (not in a function)
drivers/spi/spi-bcm-qspi.c:1301:13: error: 'bcm_qspi_resume' undeclared here (not in a function)
This replaces the #ifdef with a __maybe_unused annotation that lets
the compiler figure out whether to drop the functions itself,
and uses SIMPLE_DEV_PM_OPS() to refer to the functions.
This will also fill the freeze/thaw/poweroff/restore callback
pointers in addition to suspend/resume, but as far as I can tell,
this is what we want.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: fa236a7ef2 ("spi: bcm-qspi: Add Broadcom MSPI driver")
Signed-off-by: Mark Brown <broonie@kernel.org>
The header isn't actually needed here, but including it leads
to a build warning when CONFIG_MTD is disabled:
include/linux/mtd/cfi.h:76:2: #warning No CONFIG_MTD_CFI_Ix selected. No NOR chip support can work. [-Werror=cpp]
Fixes: fa236a7ef2 (spi: bcm-qspi: Add Broadcom MSPI driver)
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
Add definition of further register bits for use in upcoming
driver extensions and improve current bit definitions:
- use BIT macro
- use bit names as in the chip spec
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Change register access to the method used in other drivers too.
- use register names as in the chip spec for constants
- avoid hard to read statements like
__be32 __iomem *espi_mode = ®_base->mode
- get rid of old powerpc-specific functions like in_8
In addition annotate reg_base in struct mpc8xxx_spi as __iomem.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Simplify the interrupt handler a little. In addition don't call
fsl_espi_cpu_irq() if no event bit is set.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
If t is not null then the SPI core takes care that bits_per_word and
speed_hz are populated. This allows to simplify fsl_espi_setup_transfer.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
imx35 and compatible chipsets support loopback mode by setting a
loopback control bit in the test register. Make this setting available
for data transfers, similar to what we do for imx51.
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Signed-off-by: Mark Brown <broonie@kernel.org>
Modify spi_imx_clkdiv_2() to return the resulting bus clock frequency
when the selected clock divider is applied. Set spi_imx->spi_bus_clk to
this frequency.
If spi_bus_clk is unset, spi_imx_calculate_timeout() causes a
division by 0.
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Signed-off-by: Mark Brown <broonie@kernel.org>
This change implements BSPI driver for Broadcom BRCMSTB, NS2,
NSP SoCs works in combination with the MSPI controller driver
and implements flash read acceleration and implements the
spi_flash_read() method. Both MSPI and BSPI controllers are
needed to access spi-nor flash.
Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
Signed-off-by: Yendapally Reddy Dhananjaya Reddy <yendapally.reddy@broadcom.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Adding the settop SoC platfrom driver, this driver is compatible
with the settop MSPI+BSPI and MSPI only blocks implemented on the
SoCs. Driver calls the spi-bcm-qspi probe(), remove() and pm_ops.
Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Master SPI driver for Broadcom settop, iProc SoCs. The driver
is used for devices that use SPI protocol on BRCMSTB, NSP, NS2
SoCs. SoC platform driver call exported porbe(), remove()
and suspend/resume pm_ops implemented in this common driver.
Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
Signed-off-by: Yendapally Reddy Dhananjaya Reddy
Signed-off-by: Mark Brown <broonie@kernel.org>
devm_* API is supposed to be used only in probe function call.
The resource is allocated at 'probe' and free automatically at 'remove'.
Usage of devm_* functions outside probe sometimes leads to resource leak.
Thus avoid using devm_* APIs in .setup/.cleanup callbacks.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Merge both functions to reduce source code size and improve
readability.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Move checking for a zero-length message up in the call chain and
use m->frame_length instead of re-calculating the overall length
of all transfers in the message.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Factor out copying read data to the read buffers in the original
message to a new function fsl_espi_copy_from_buf.
This also allows to simplify fsl_espi_copy_to_buf.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Better structure the code by population all elements of struct
spi_transfer in one place.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
