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path: root/drivers/spi/spi-dw.c
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2019-02-20Merge branch 'for-5.0' of ↵Mark Brown
https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi into spi-5.1
2019-01-24spi: dw: Fix default polarity of native chipselectLinus Walleij
The DW controller also supports platforms specifying native chipselects. When I enforce the use of high CS for drivers opting in for using GPIO descriptors, I inadvertedly switched the driver to also use active high chip select for native chip selects. As it turns out, the DW hardware driving chip selects also thinks it is weird with active low chip selects so all we need to do is remove an inversion in the driver. Cc: Jan Kotas <jank@cadence.com> Reported-by: Jan Kotas <jank@cadence.com> Tested-by: Jan Kotas <jank@cadence.com> Fixes: 9400c41e77b8 ("spi: dw: Convert to use CS GPIO descriptors") Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Mark Brown <broonie@kernel.org>
2019-01-15spi: dw: change snprintf to scnprintf for possible overflowSilvio Cesare
Change snprintf to scnprintf. There are generally two cases where using snprintf causes problems. 1) Uses of size += snprintf(buf, SIZE - size, fmt, ...) In this case, if snprintf would have written more characters than what the buffer size (SIZE) is, then size will end up larger than SIZE. In later uses of snprintf, SIZE - size will result in a negative number, leading to problems. Note that size might already be too large by using size = snprintf before the code reaches a case of size += snprintf. 2) If size is ultimately used as a length parameter for a copy back to user space, then it will potentially allow for a buffer overflow and information disclosure when size is greater than SIZE. When the size is used to index the buffer directly, we can have memory corruption. This also means when size = snprintf... is used, it may also cause problems since size may become large. Copying to userspace is mitigated by the HARDENED_USERCOPY kernel configuration. The solution to these issues is to use scnprintf which returns the number of characters actually written to the buffer, so the size variable will never exceed SIZE. Signed-off-by: Silvio Cesare <silvio.cesare@gmail.com> Signed-off-by: Willy Tarreau <w@1wt.eu> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Mark Brown <broonie@kernel.org>
2019-01-10spi: dw: fix warning unused variable 'ret'Anders Roxell
When CONFIG_SPI_DESIGNWARE are enabled we see the unused variable warning in dw_spi_setup. ../drivers/spi/spi-dw.c: In function ‘dw_spi_setup’: ../drivers/spi/spi-dw.c:400:6: warning: unused variable ‘ret’ [-Wunused-variable] int ret; ^~~ Remove the unused varable. Fixes: 9400c41e77b8 ("spi: dw: Convert to use CS GPIO descriptors") Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Anders Roxell <anders.roxell@linaro.org> Signed-off-by: Mark Brown <broonie@kernel.org>
2019-01-09spi: dw: Convert to use CS GPIO descriptorsLinus Walleij
This converts the DesignWare (dw) SPI master driver to use GPIO descriptors for chip select handling. This driver has a duplicate DT parser in addition to the one in the core, sets up the line as non-asserted and relies on the core to drive the GPIOs. It is a pretty straight-forward conversion. Cc: Talel Shenhar <talel@amazon.com> Cc: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Linuxarm <linuxarm@huawei.com> Tested-by: Jay Fang <f.fangjian@huawei.com> Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Mark Brown <broonie@kernel.org>
2019-01-07spi: dw: fix potential variable assignment errorshaftarger
spi::mode is defined by framework for several SPI capabilities, such as polarity, phase, bit-endian, wire number. Directly use this variable for setting controller's polarity and phase causes other bit in register being set. Since SPI framework has its definition, SPI_CPOL and SPI_CPHA offset may be changed by framwork change. Instead of just mask off the relevant bits, fetch required bit in spi::mode and set to register. Signed-off-by: shaftarger <shol@livemail.tw> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-12-04spi: dw-mmio: add ACPI supportJay Fang
The Hisilicon Hip08 platform, that uses ACPI, has this controller. Let's add ACPI support for DW SPI MMIO-based host. The ACPI ID used is "HISI0173" for the Designware SPI controller of Hisilicon Hip08 platform. Signed-off-by: Jay Fang <f.fangjian@huawei.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2018-10-11dw: spi: add support for Amazon's Alpine spi controllerTalel Shenhar
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>
2018-09-06spi: dw: support 4-16 bits per wordSimon Goldschmidt
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>
2018-09-05spi: Do not print a message if spi_controller_{suspend,resume}() failsGeert Uytterhoeven
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>
2018-08-10Merge branch 'spi-4.19' into spi-nextMark Brown
2018-07-30spi: dw: export dw_spi_set_csAlexandre Belloni
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>
2018-07-18spi: dw: allow providing own set_cs callbackAlexandre Belloni
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>
2018-07-18spi: dw: fix possible race conditionAlexandre Belloni
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>
2018-02-12spi: dw: Convert to generalized SPI controller APIJarkko Nikula
Convert to generalized SPI controller API introduced by the commit 8caab75fd2c2 ("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>
2018-01-26spi: dw: Remove unused members from struct chip_dataJarkko Nikula
Local struct chip_data has two members that are not used: - cs. Looks like was never used - enable_dma. Became unused by the commit f89a6d8f43eb ("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>
2017-01-09spi: dw: Make debugfs use bus num and make irq name uniquePhil Reid
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>
2016-12-31spi: dw: Make debugfs name unique between instancesPhil Reid
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>
2016-10-11spi: dw: Set GPIO_SS flag to toggle Slave Select on GPIO CSThor Thayer
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>
2016-09-12spi: dw: round up result of calculation for clock dividerMatthias Seidel
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>
2016-09-06spi: dw: fix multiple slaves with different baudratesMatthias Seidel
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>
2015-12-23spi: dw: Use SPI_TMOD_TR rather than magic const 0 to set tmodeJisheng Zhang
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>
2015-10-28spi: dw: replace magic constant by DW_SPI_DRAndy Shevchenko
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>
2015-10-20spi: dw: remove a NULL check when call ->remove()Andy Shevchenko
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>
2015-10-20spi: dw: explicitly free IRQ handler in dw_spi_remove_host()Andy Shevchenko
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: 04f421e7b0b1 (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>
2015-10-19spi: dw: introduce spi_shutdown_chip()Andy Shevchenko
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>
2015-10-19spi: dw: eliminate unused threshold variablesAndy Shevchenko
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>
2015-10-19spi: dw: eliminate speed variable in ->transfer_one()Andy Shevchenko
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>
2015-10-19spi: dw: remove bits_per_word member of struct chip_dataAndy Shevchenko
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>
2015-10-19spi: dw: remove unneeded cr0 member of struct chip_dataAndy Shevchenko
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 0ed36990a93b (spi: dw: Remove needless if statements). Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Mark Brown <broonie@kernel.org>
2015-10-19spi: dw: use plain struct device * at earlier ->probe()Andy Shevchenko
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>
2015-09-17spi: dw: Remove test for non-zero spi->max_speed_hzJarkko Nikula
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>
2015-09-17spi: dw: Remove needless if statementsJarkko Nikula
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>
2015-08-21spi: dw: Allow interface drivers to limit data I/O to word sizesMichael van der Westhuizen
The commit dd11444327ce ("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: dd11444327ce ("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>
2015-03-25spi: dw: fix crash on setup stageAndy Shevchenko
The commit 1a7b7ee72c21 (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>
2015-03-17spi: dw-spi: Convert 16bit accesses to 32bit accessesThor Thayer
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>
2015-03-09spi: dw-spi: Single Register read to clear IRQsThor Thayer
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>
2015-03-09spi: dw-mid: move to use core SPI DMA mappingsAndy Shevchenko
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>
2015-03-09spi: dw-mid: clear ongoing DMA transfers on timeoutAndy Shevchenko
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>
2015-03-09spi: dw-mid: split dma_setup() from dma_transfer()Andy Shevchenko
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>
2015-03-09spi: dw-mid: convert value of dma_width to enum dma_slave_buswidthAndy Shevchenko
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>
2015-03-09Merge branch 'fix/dw' of ↵Mark Brown
git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi into spi-dw
2015-03-06spi: dw: move to SPI core message handlingAndy Shevchenko
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>
2015-03-06spi: dw: program registers as soon as possibleAndy Shevchenko
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>
2015-03-06spi: dw: make sure SPI controller is enabledAndy Shevchenko
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>
2015-02-26spi: dw: revisit FIFO size detection againAndy Shevchenko
The commit d297933cc7fc (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: d297933cc7fc (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
2015-02-24spi: dw: always reprogram CTRL0Andy Shevchenko
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>
2015-02-24spi: dw: refactor code that handles clk_divAndy Shevchenko
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>
2015-02-24spi: dw: get TX level without an additional variableAndy Shevchenko
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>
2015-02-24spi: dw: move piece of code out of conditionAndy Shevchenko
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>
generated by cgit (git 2.34.1) at 2024-05-27 09:32:31 +0000