2
0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-28 07:04:00 +08:00
Commit Graph

78 Commits

Author SHA1 Message Date
Talel Shenhar
f2d7047948
dw: spi: add support for Amazon's Alpine spi controller
Add support for a new devicetree compatible string called
'amazon,alpine-apb-ssi', which is necessary for the Amazon Alpine spi
controller. 'amazon,alpine-dw-apb-ssi' is used in the dw spi driver if
specified in the devicetree.  Otherwise, fall back to driver default
behavior, i.e. original dw IP hw driver behavior.

Signed-off-by: Talel Shenhar <talel@amazon.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-10-11 15:11:04 +01:00
Simon Goldschmidt
af060b3f72
spi: dw: support 4-16 bits per word
The spi-dw driver currently only supports 8 or 16 bits per word.

Since the hardware supports 4-16 bits per word, adapt the driver
to also support this.

Tested on socfpga cyclone5 with a 9-bit SPI display.

Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-09-06 12:09:37 +01:00
Geert Uytterhoeven
7c5d8a249a
spi: Do not print a message if spi_controller_{suspend,resume}() fails
spi_controller_{suspend,resume}() already prints an error message on
failure, so there is no need to repeat this in individual drivers.

Note: spi_master_{suspend,resume}() is an alias for
      spi_controller_{suspend,resume}().

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Reviewed-by: Daniel Mack <daniel@zonque.org>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-09-05 12:38:27 +01:00
Mark Brown
c1acb21b32
Merge branch 'spi-4.19' into spi-next 2018-08-10 17:51:52 +01:00
Alexandre Belloni
c79bdbb490
spi: dw: export dw_spi_set_cs
Export dw_spi_set_cs so it can be used from the various IP integration
modules.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-07-30 12:02:07 +01:00
Alexandre Belloni
62dbbae483
spi: dw: allow providing own set_cs callback
Allow platform specific drivers to provide their own set_cs callback when
the IP integration requires it.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-07-18 13:22:37 +01:00
Alexandre Belloni
66b19d7623
spi: dw: fix possible race condition
It is possible to get an interrupt as soon as it is requested.  dw_spi_irq
does spi_controller_get_devdata(master) and expects it to be different than
NULL. However, spi_controller_set_devdata() is called after request_irq(),
resulting in the following crash:

CPU 0 Unable to handle kernel paging request at virtual address 00000030, epc == 8058e09c, ra == 8018ff90
[...]
Call Trace:
[<8058e09c>] dw_spi_irq+0x8/0x64
[<8018ff90>] __handle_irq_event_percpu+0x70/0x1d4
[<80190128>] handle_irq_event_percpu+0x34/0x8c
[<801901c4>] handle_irq_event+0x44/0x80
[<801951a8>] handle_level_irq+0xdc/0x194
[<8018f580>] generic_handle_irq+0x38/0x50
[<804c6924>] ocelot_irq_handler+0x104/0x1c0

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-07-18 13:21:33 +01:00
Jarkko Nikula
721483e288
spi: dw: Convert to generalized SPI controller API
Convert to generalized SPI controller API introduced by the
commit 8caab75fd2 ("spi: Generalize SPI "master" to "controller"").
Inside driver variable name "master" is still used to indicate the driver
is master only.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-02-12 12:04:16 +00:00
Jarkko Nikula
993181e151
spi: dw: Remove unused members from struct chip_data
Local struct chip_data has two members that are not used:

- cs. Looks like was never used
- enable_dma. Became unused by the commit f89a6d8f43 ("spi: dw-mid: move
  to use core SPI DMA mappings").

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2018-01-26 14:50:43 +00:00
Phil Reid
e70002c80d spi: dw: Make debugfs use bus num and make irq name unique
Instead of using device name it was suggested that bus number was more
appropriate to differentiate debugfs names. Also reduce buffer size to
more realistic 32 bytes instead of 128.

When request_irq is called the bus number may not be assigned. Therefore
the irq name was not unique when dynamic bus number was being used.
As per most of the spi drivers use the device name instead. No other
use of dws->name could be found so it was removed.

Signed-off-by: Phil Reid <preid@electromag.com.au>
Signed-off-by: Mark Brown <broonie@kernel.org>
2017-01-09 11:22:14 +00:00
Phil Reid
13288bdf4a spi: dw: Make debugfs name unique between instances
Some system have multiple dw devices. Currently the driver uses a
fixed name for the debugfs dir. Append dev name to the debugfs dir
name to make it unique.

Signed-off-by: Phil Reid <preid@electromag.com.au>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-12-31 18:51:03 +00:00
Thor Thayer
80b444e579 spi: dw: Set GPIO_SS flag to toggle Slave Select on GPIO CS
The Designware SPI master requires slave selection before the transfer
can begin [1].

This patch uses the new master flag to indicate both the GPIO CS and
the internal chip select should be used.

Tested On:
    Altera CycloneV development kit
    Compile tested for build errors on x86_64 (allyesconfigs)

[1] DesignWare dw_apb_ssi Databook, Version 3.20a (page 39)

Signed-off-by: Thor Thayer <tthayer@opensource.altera.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-10-11 12:29:04 +02:00
Matthias Seidel
3aef463222 spi: dw: round up result of calculation for clock divider
Avoid ending up with a higher frequency than requested

Signed-off-by: Matthias Seidel <kernel@mseidel.net>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-09-12 19:59:08 +01:00
Matthias Seidel
13b10301b8 spi: dw: fix multiple slaves with different baudrates
Add current master clock to dws struct and compare it against the
requestedtransfer speed. Update clock divider only if necessary.

Signed-off-by: Matthias Seidel <kernel@mseidel.net>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-09-06 11:53:50 +01:00
Jisheng Zhang
6096828e68 spi: dw: Use SPI_TMOD_TR rather than magic const 0 to set tmode
The TMODE available value is well defined and documented in the header
file. Use it and remove the comment.

Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-12-23 12:12:09 +00:00
Andy Shevchenko
d7ef54ca12 spi: dw: replace magic constant by DW_SPI_DR
The offset 0x60 is the offset of the data register defined as DW_SPI_DR in the
header file. Use it.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-10-28 09:17:48 +09:00
Andy Shevchenko
f4aaa1c8a5 spi: dw: remove a NULL check when call ->remove()
Currently all users aware about calling dw_spi_remove_host() with properly set
parameter. Remove unneeded check.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-10-20 15:45:43 +01:00
Andy Shevchenko
02f20387e1 spi: dw: explicitly free IRQ handler in dw_spi_remove_host()
The following warning occurs when DW SPI is compiled as a module and it's a PCI
device. On the removal stage pcibios_free_irq() is called earlier than
free_irq() due to the latter is called at managed resources free strage.

------------[ cut here ]------------
WARNING: CPU: 1 PID: 1003 at /home/andy/prj/linux/fs/proc/generic.c:575 remove_proc_entry+0x118/0x150()
remove_proc_entry: removing non-empty directory 'irq/38', leaking at least 'dw_spi1'
Modules linked in: spi_dw_midpci(-) spi_dw [last unloaded: dw_dmac_core]
CPU: 1 PID: 1003 Comm: modprobe Not tainted 4.3.0-rc5-next-20151013+ #32
 00000000 00000000 f5535d70 c12dc220 f5535db0 f5535da0 c104e912 c198a6bc
 f5535dcc 000003eb c198a638 0000023f c11b4098 c11b4098 f54f1ec8 f54f1ea0
 f642ba20 f5535db8 c104e96e 00000009 f5535db0 c198a6bc f5535dcc f5535df0
Call Trace:
 [<c12dc220>] dump_stack+0x41/0x61
 [<c104e912>] warn_slowpath_common+0x82/0xb0
 [<c11b4098>] ? remove_proc_entry+0x118/0x150
 [<c11b4098>] ? remove_proc_entry+0x118/0x150
 [<c104e96e>] warn_slowpath_fmt+0x2e/0x30
 [<c11b4098>] remove_proc_entry+0x118/0x150
 [<c109b96a>] unregister_irq_proc+0xaa/0xc0
 [<c109575e>] free_desc+0x1e/0x60
 [<c10957d2>] irq_free_descs+0x32/0x70
 [<c109b1a0>] irq_domain_free_irqs+0x120/0x150
 [<c1039e8c>] mp_unmap_irq+0x5c/0x60
 [<c16277b0>] intel_mid_pci_irq_disable+0x20/0x40
 [<c1627c7f>] pcibios_free_irq+0xf/0x20
 [<c13189f2>] pci_device_remove+0x52/0xb0
 [<c13f6367>] __device_release_driver+0x77/0x100
 [<c13f6da7>] driver_detach+0x87/0x90
 [<c13f5eaa>] bus_remove_driver+0x4a/0xc0
 [<c128bf0d>] ? selinux_capable+0xd/0x10
 [<c13f7483>] driver_unregister+0x23/0x60
 [<c10bad8a>] ? find_module_all+0x5a/0x80
 [<c1317413>] pci_unregister_driver+0x13/0x60
 [<f80ac654>] dw_spi_driver_exit+0xd/0xf [spi_dw_midpci]
 [<c10bce9a>] SyS_delete_module+0x17a/0x210

Explicitly call free_irq() at removal stage of the DW SPI driver.

Fixes: 04f421e7b0 (spi: dw: use managed resources)
Cc: stable@vger.kernel.org
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-10-20 15:45:43 +01:00
Andy Shevchenko
1cc3f141f0 spi: dw: introduce spi_shutdown_chip()
This helper disables SPI controller and sets clock to 0.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-10-19 20:32:01 +01:00
Andy Shevchenko
d53c0ef319 spi: dw: eliminate unused threshold variables
The tx_threshold and rx_threshold variables are not used anywhere. Remove them.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-10-19 20:32:01 +01:00
Andy Shevchenko
de6feda884 spi: dw: eliminate speed variable in ->transfer_one()
There is no point to have a separate variable for speed in ->transfer_one().

While here, remove !chip->clk_div from a condition since it is assigned
simultaneously with chip->speed_hz. We can do this safely because
 a) transfer speed can't be higher than max_freq and therefore chip->clk_div
    can be 0 only when chip->speed_hz is 0, and
 b) transfer speed can't be 0, otherwise we will get division by zero
    exception.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-10-19 20:32:01 +01:00
Andy Shevchenko
863cb2f72e spi: dw: remove bits_per_word member of struct chip_data
There is no need to carry over spi->bits_per_word and Co from ->setup() in
struct chip_data since ->transfer_one() will anyway take the transfer
parameters from struct spi_transfer. This is since SPI core validates both
bits_per_word transfer parameter and defaults to spi->bits_per_word in case
that per transfer parameter is not set.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-10-19 20:32:01 +01:00
Andy Shevchenko
4adb1f8f88 spi: dw: remove unneeded cr0 member of struct chip_data
Since we recalculate cr0 each time we start a transfer the chip_data->cr0
becomes redundant. Remove it and related pieces.

This is a follow up to commit 0ed36990a9 (spi: dw: Remove needless if
statements).

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-10-19 20:31:57 +01:00
Andy Shevchenko
5f0966e61f spi: dw: use plain struct device * at earlier ->probe()
The name of the master device is set during registrationg which happens after
we issue the error message. Change it to plain struct device * to see which
device registration failed.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-10-19 20:31:57 +01:00
Jarkko Nikula
55f9a0706f spi: dw: Remove test for non-zero spi->max_speed_hz
Test for non-zero spi->max_speed_hz in dw_spi_setup() looks needless as
spi_setup() defaults to master->max_speed_hz in case it is not set. This
drivers sets the master->max_speed_hz based on max_freq data passed to it
via dw_spi_add_host() call. I suppose things have already fallen apart if
dw_spi_mmio_probe() or spi_pci_probe() ever passes zero max_freq.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-09-17 18:35:25 +01:00
Jarkko Nikula
0ed36990a9 spi: dw: Remove needless if statements
SPI core validates both bits_per_word and speed_hz transfer parameters and
defaults to spi->bits_per_word and spi->max_speed_hz in case these per
transfer parameters are not set. This allows to remove related if
statements as they evaluate always to true and reduce indentation.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-09-17 18:35:25 +01:00
Michael van der Westhuizen
c4fe57f762 spi: dw: Allow interface drivers to limit data I/O to word sizes
The commit dd11444327 ("spi: dw-spi: Convert 16bit accesses to 32bit
accesses") changed all 16bit accesses in the DW_apb_ssi driver to 32bit.
This, unfortunately, breaks data register access on picoXcell, where the
DW IP needs data register accesses to be word accesses (all other
accesses appear to be OK).

This change introduces a new master variable to allow interface drivers
to specify that 16bit data transfer I/O is required.  This change also
introduces the ability to set this variable via device tree bindings in
the MMIO interface driver.  Both the core and the MMIO interface driver
default to the current 32bit behaviour.

Before this change, on a picoXcell pc3x3:
 spi_master spi32766: interrupt_transfer: fifo overrun/underrun
 m25p80 spi32766.0: error -5 reading 9f
 m25p80: probe of spi32766.0 failed with error -5

After this change:
 m25p80 spi32766.0: m25p40 (512 Kbytes)

Fixes: dd11444327 ("spi: dw-spi: Convert 16bit accesses to 32bit accesses")
Signed-off-by: Michael van der Westhuizen <michael@smart-africa.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-08-21 10:25:28 -07:00
Andy Shevchenko
207cda93f0 spi: dw: fix crash on setup stage
The commit 1a7b7ee72c (spi: Ensure that CS line is in non-active state after
spi_setup()) introduces an unconditional call of spi_set_cs() before ->setup().
The dw_spi_set_cs() relies on that fact that ->setup() is already called, but
it doesn't now. This patch fixes the crash by adding an additional check to
dw_spi_set_cs().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-03-25 11:54:40 -07:00
Thor Thayer
dd11444327 spi: dw-spi: Convert 16bit accesses to 32bit accesses
Altera's Arria10 SoC interconnect requires a 32-bit write for APB
peripherals. The current spi-dw driver uses 16-bit accesses in
some locations. This patch converts all the 16-bit reads and
writes to 32-bit reads and writes.

Additional Documentation to Support this Change:
The DW_apb_ssi databook states:
"All registers in the DW_apb_ssi are addressed at 32-bit boundaries
to remain consistent with the AHB bus. Where the physical size of
any register is less than 32-bits wide, the upper unused bits of
the 32-bit boundary are reserved. Writing to these bits has no
effect; reading from these bits returns 0." [1]

[1] Section 6.1 of dw_apb_ssi.pdf (version 3.22a)

Request for test with platforms using the DesignWare SPI IP.

Tested On:
Altera CycloneV development kit
Altera Arria10 development kit
Compile tested for build errors on x86_64 (allyesconfigs)

Signed-off-by: Thor Thayer <tthayer@opensource.altera.com>
Reviewed-and-tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-03-17 12:27:09 +00:00
Thor Thayer
2306509605 spi: dw-spi: Single Register read to clear IRQs
Instead of clearing the RxU, RxO, and TxO IRQs individually with
3 register reads, a single read of the ICR register will do the
same thing.

Signed-off-by: Thor Thayer <tthayer@opensource.altera.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-03-09 18:43:44 +00:00
Andy Shevchenko
f89a6d8f43 spi: dw-mid: move to use core SPI DMA mappings
SPI core has a comprehensive function set to map and unmap a message when it's
needed. This patch converts driver to use that advantage.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-03-09 18:11:13 +00:00
Andy Shevchenko
4d5ac1edfd spi: dw-mid: clear ongoing DMA transfers on timeout
This patch shuts up any ongoing DMA transfer in case of error.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-03-09 18:11:13 +00:00
Andy Shevchenko
9f14538ecd spi: dw-mid: split dma_setup() from dma_transfer()
The patch splits DMA preparatory code to dma_setup() callback. The change also
converts transfer_one() to program DMA whenever the transfer is DMA mapped. The
change is a follow up of the converion to use SPI core transfer_one_message().
Since the DMA mapped transfers can be interleaved with PIO ones the DMA related
configuration should respect that.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-03-09 18:11:13 +00:00
Andy Shevchenko
e31abce778 spi: dw-mid: convert value of dma_width to enum dma_slave_buswidth
DMAEngine has a specific type to be used for bus width. This patch converts the
code to use the values of the specific type when configure DMA transfer.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-03-09 18:11:13 +00:00
Mark Brown
0365fbd4bb Merge branch 'fix/dw' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi into spi-dw 2015-03-09 18:11:06 +00:00
Andy Shevchenko
c22c62db3f spi: dw: move to SPI core message handling
This patch removes a lot of duplicate code since SPI core provides a nice
message handling.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-03-06 20:33:38 +00:00
Andy Shevchenko
0b2e8915ea spi: dw: program registers as soon as possible
This patch refactors the code in pump_transfers() to reprogram the registers
immediately when we have a new configuration data. The behaviour is slightly
modified:
 - chip is always disabled and reenabled
 - CTRL0 is always reprogrammed

This change allows to do a further refactoring and simplier conversion to use
SPI core DMA routines in the future.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-03-06 20:29:03 +00:00
Andy Shevchenko
45746e82cf spi: dw: make sure SPI controller is enabled
The error handling is partially broken since the controller is disabled on
error and is not re-enabled until condition occurs, i.e. mode (poll, PIO/DMA),
chip (cs_change), or speed (clk_div) is changed. In the result of these changes
we will have a predictable state of the SPi controller independently on how
successfull was a previous transfer.

The patch disables interrupts and re-enables the SPI controller wherever it
needs to be done. Thus most of the time the SPI controller is kept enabled. The
runtime PM, when it will be implemented, must take care of the controller
disabling and re-enabling.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-03-06 20:29:03 +00:00
Andy Shevchenko
9d239d353c spi: dw: revisit FIFO size detection again
The commit d297933cc7 (spi: dw: Fix detecting FIFO depth) tries to fix the
logic of the FIFO detection based on the description on the comments. However,
there is a slight difference between numbers in TX Level and TX FIFO size.

So, by specification the FIFO size would be in a range 2-256 bytes. From TX
Level prospective it means we can set threshold in the range 0-(FIFO size - 1)
bytes. Hence there are currently two issues:
  a) FIFO size 2 bytes is actually skipped since TX Level is 1 bit and could be
     either 0 or 1 byte;
  b) FIFO size is incorrectly decreased by 1 which already done by meaning of
     TX Level register.

This patch fixes it eventually right.

Fixes: d297933cc7 (spi: dw: Fix detecting FIFO depth)
Reviewed-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
2015-02-26 11:09:51 +09:00
Andy Shevchenko
1a18f9f753 spi: dw: always reprogram CTRL0
Instead of an additional reading from the register let's update it even if the
value is kept the same.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-02-24 23:43:34 +09:00
Andy Shevchenko
341c7dc7c0 spi: dw: refactor code that handles clk_div
This patch does the following changes:

a) the calculation of clk_div is simplified to oneliner;

b) chip->clk_div is updated if clk_div is not zero, therefore the condition is
   simplified by using chip->clk_div in both cases;

c) while here, the redundant parentheses are removed.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-02-24 23:43:34 +09:00
Andy Shevchenko
ea11370fff spi: dw: get TX level without an additional variable
There is no need to have an additional variable to get a TX level. The patch
refactors this piece of code.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-02-24 23:43:34 +09:00
Andy Shevchenko
39bc03bfec spi: dw: move piece of code out of condition
There is no sense to keep a member assignment in the internal structure inside
the condition which reprograms HW. It makes code readability better if kept
outside of the condition.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-02-24 23:43:33 +09:00
Andy Shevchenko
30b4b703a5 spi: dw: print debug message with FIFO size
When autodetection is used it would be useful to know what the FIFO size is.
The patch adds a debug message for this purpose.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-01-07 18:01:06 +00:00
Andy Shevchenko
3dbb3b98e8 spi: dw: amend warning message
In case of warning message in ->probe() we have to use HW device name instead
of master because last is not defined yet.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-01-07 17:58:54 +00:00
Axel Lin
d297933cc7 spi: dw: Fix detecting FIFO depth
Current code tries to find the highest valid fifo depth by checking the value
it wrote to DW_SPI_TXFLTR. There are a few problems in current code:
1) There is an off-by-one in dws->fifo_len setting because it assumes the latest
   register write fails so the latest valid value should be fifo - 1.
2) We know the depth could be from 2 to 256 from HW spec, so it is not necessary
   to test fifo == 257. In the case fifo is 257, it means the latest valid
   setting is fifo = 256. So after the for loop iteration, we should check
   fifo == 2 case instead of fifo == 257 if detecting the FIFO depth fails.
This patch fixes above issues.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Reviewed-and-tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
2015-01-05 19:04:39 +00:00
Mark Brown
ec058615f1 Merge remote-tracking branches 'spi/fix/dw' and 'spi/fix/sirf' into spi-linus 2014-11-26 19:05:25 +00:00
Thor Thayer
0a8727e697 spi: dw: Fix dynamic speed change.
An IOCTL call that calls spi_setup() and then dw_spi_setup() will
overwrite the persisted last transfer speed. On each transfer, the
SPI speed is compared to the last transfer speed to determine if the
clock divider registers need to be updated (did the speed change?).
This bug was observed with the spidev driver using spi-config to
update the max transfer speed.

This fix: Don't overwrite the persisted last transaction clock speed
when updating the SPI parameters in dw_spi_setup(). On the next
transaction, the new speed won't match the persisted last speed
and the hardware registers will be updated.
On initialization, the persisted last transaction clock
speed will be 0 but will be updated after the first SPI
transaction.

Move zeroed clock divider check into clock change test because
chip->clk_div is zero on startup and would cause a divide-by-zero
error. The calculation was wrong as well (can't support odd #).

Reported-by: Vlastimil Setka <setka@vsis.cz>
Signed-off-by: Vlastimil Setka <setka@vsis.cz>
Signed-off-by: Thor Thayer <tthayer@opensource.altera.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
2014-11-07 10:14:59 +00:00
Thor Thayer
9c6de47d53 spi: dw: Initialize of_node to discover DT node children
The of_node element must be initialized to enable discovery of node
children which takes place in the of_register_spi_devices() function.

Signed-off-by: Thor Thayer <tthayer@opensource.altera.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2014-10-08 21:12:47 +01:00
Mark Brown
7020d76971 Merge remote-tracking branches 'spi/topic/davinci', 'spi/topic/doc', 'spi/topic/dw' and 'spi/topic/fsl' into spi-next 2014-10-03 16:33:39 +01:00