Patch reuse existing "chip_select" and "cs_gpio(s)" fields from SPI core.
Signed-off-by: NAlexander Shiyan <shc_work@mail.ru>
Signed-off-by: NMark Brown <broonie@kernel.org>

transfer could be NULL in spi_imx_can_dma() when it's called from
spi_imx_setupxfer() with a NULL transfer. Test for a NULL pointer before
dereferencing it.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

If the SPI chip select (CS) for a dedicated channel is done manually by
the used higher device driver, the CS may be active while writing to
ECSPIx_CONFIGREG. To prevent unwanted clock edges when selecting
the clock mode,  only do the necessary changes to the i.MX SPI
configuration register and leave not selected channels untouched.

To prevent unwanted clock edges on first use, an empty dummy
transmission shall be done by the initialization procedure of the device
driver of this channel. This will set the clock mode to the correct state.
Signed-off-by: NKnut Wohlrab <knut.wohlrab@de.bosch.com>
Signed-off-by: NDirk Behme <dirk.behme@de.bosch.com>
Acked-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NMark Brown <broonie@kernel.org>

The driver tries to be clever by only setting up DMA channels when
the corresponding sg tables are non NULL. The sg tables are embedded
structs in struct spi_transfer, so they are guaranteed to be non NULL
which makes the if(tx)/if(rx) tests completely bogus. The driver even
sets the SPI_MASTER_MUST_RX / SPI_MASTER_MUST_TX flags which makes sure
the sg tables are not only present but also non empty.
Drop the tests and make the DMA path easier to follow.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NMark Brown <broonie@kernel.org>

Now that the config function knows whether we are doing DMA or not we
can do the necessary register setup in the config function and no longer
have to do this in the trigger function. With this the trigger function
becomes a no-op for DMA, so instead of testing if we are doing DMA or
not in the trigger function we simply no longer call it in the DMA case.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NMark Brown <broonie@kernel.org>

The watermark levels in the DMA register are write only, the driver
should never have to read them back from the hardware. Replace the
current _MASK and _OFFSET defines with defines taking the watermark
level directly.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NMark Brown <broonie@kernel.org>

This reverts patch 1476253c (spi: imx: fix ecspi mode setup)
The patch tried to fix something by clearing bits in the cfg variable,
but cfg is initialized to zero on function entry. There are no bits to
clear.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NMark Brown <broonie@kernel.org>

DMA transfer for SPI was limited to up to 8 bits word size until now.
Sync in SPI burst size and DMA bus width is necessary to correctly
support 16 and 32 BPW.
Signed-off-by: NAnton Bondarenko <anton.bondarenko.sama@gmail.com>
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NMark Brown <broonie@kernel.org>

There's no need for an extra dma_is_inited variable when we can
equally well check for the existence of a DMA channel.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NMark Brown <broonie@kernel.org>

When the MX51_ECSPI_DMA is configured we control every single bit
of the register, so there's no need to read/modify/write it. Instead
just write the value we want to have in the register. Also, drop
unnecessary check if we are actually doing DMA. The values written
to the register have no effect in PIO mode and value written there
during the last DMA transfer is still in the register, so we can
equally well always write a value.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NMark Brown <broonie@kernel.org>

The SoC specific config function does not know if DMA will be used or
not. This information will be useful to configure the SPI controller
correctly for DMA in following patches, so initialize the usedma
variable before calling into the SoC specific config function.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NMark Brown <broonie@kernel.org>

At the moment the driver decides to fallback to PIO mode the buffers
are already mapped for DMA. It's a bug to access them with the CPU
afterwards, so we cannot just fallback to PIO mode.
It should not be necessary anyway, since we only use DMA when we
verified that it's possible in the fist place, so when prep_slave_sg
fails it's a bug, either in the SDMA driver or in the can_dma
implementation.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NMark Brown <broonie@kernel.org>

Fixed timeout value can fire while transaction is ongoing. This may happen
because there are no strict requirements on SPI transaction duration.
Dynamic timeout value is generated based on SCLK and transaction size.

There is also 4 * SCLK delay between TX bursts related to HW internal CS change.
Signed-off-by: NAnton Bondarenko <anton.bondarenko.sama@gmail.com>
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NMark Brown <broonie@kernel.org>

In spi_imx_dma_transfer(), when desc_rx = dmaengine_prep_slave_sg()
fails, the context goes to label no_dma and then return. However,
the memory allocated for desc_tx has not been freed yet, which leads
to resource leak.
Signed-off-by: NGao Pan <pandy.gao@nxp.com>
Reviewed-by: NFugang Duan <B38611@freescale.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Add a struct device * member to the private driver data and use
it to print messages using dev_* functions rather than pr_*.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NMark Brown <broonie@kernel.org>

RX DMA tail data handling doesn't work correctly in many cases with current
implementation. It happens because SPI core was setup to generates both RX
and RX TAIL events. And RX TAIL event does not work correctly.
This can be easily verified by sending SPI transaction with size modulus
WML(32 in our case) not equal 0.

Also removing change introduced in f6ee9b58
since this change only fix usecases with transfer size from 33 to 128 bytes
and doesn't fix 129 bytes and bigger.

This is output from transaction with len 138 bytes in loopback mode at 10Mhz:
TX0000: a3 97 a2 55 53 be f1 fc f9 79 6b 52 14 13 e9 e2
TX0010: 2d 51 8e 1f 56 08 57 27 a7 05 d4 d0 52 82 77 75
TX0020: 1b 99 4a ed 58 3d 6a 52 36 d5 24 4a 68 8e ad 95
TX0030: 5f 3c 35 b5 c4 8c dd 6c 11 32 3d e2 b4 b4 59 cf
TX0040: ce 23 3d 27 df a7 f9 96 fc 1e e0 66 2c 0e 7b 8c
TX0050: ca 30 42 8f bc 9f 7b ce d1 b8 b1 87 ec 8a d6 bb
TX0060: 2e 15 63 0e 3c dc a4 3a 7a 06 20 a7 93 1b 34 dd
TX0070: 4c f5 ec 88 96 68 d6 68 a0 09 6f 8e 93 47 c9 41
TX0080: db ac cf 97 89 f3 51 05 79 71

RX0000: a3 97 a2 55 53 be f1 fc f9 79 6b 52 14 13 e9 e2
RX0010: 2d 51 8e 1f 56 08 57 27 a7 05 d4 d0 52 82 77 75
RX0020: 1b 99 4a ed 58 3d 6a 52 36 d5 24 4a 68 8e ad 95
RX0030: 5f 3c 35 00 00 b5 00 00 00 c4 00 00 8c 00 00 dd
RX0040: 6c 11 32 3d e2 b4 b4 59 cf ce 23 3d 27 df a7 f9
RX0050: 96 fc 1e e0 66 2c 0e 7b 8c ca 30 42 8f 1f 1f bc
RX0060: 9f 7b ce d1 b8 b1 87 ec 8a d6 bb 2e 15 63 0e ed
RX0070: ed 3c 58 58 58 dc 3d 3d a4 6a 6a 3a 52 52 7a 36
RX0080: 06 20 a7 93 1b 34 dd 4c f5 ec

Zeros at offset 33 and 34 caused by reading empty RX FIFO which not possible
if DMA RX read was triggered by RX event. This mean DMA was triggered
by RX TAIL event.
Signed-off-by: NAnton Bondarenko <anton.bondarenko.sama@gmail.com>
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NMark Brown <broonie@kernel.org>

In spi_imx_dma_transfer(), when desc_rx = dmaengine_prep_slave_sg()
fails, the context goes to label no_dma and then return. However,
the memory allocated for desc_tx has not been freed yet, which leads
to resource leak.
Signed-off-by: NGao Pan <pandy.gao@nxp.com>
Reviewed-by: NFugang Duan <B38611@freescale.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

If SPI device supports DMA mode, but DMA controller is not yet
available due to e.g. a delay in the corresponding kernel module
initialization, retry to initialize SPI driver later on instead of
falling back into PIO only mode.
Signed-off-by: NAnton Bondarenko <anton.bondarenko.sama@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

On SDMA initialization return exactly the same error, which is
reported by dma_request_slave_channel_reason(), it is a preceding
change to defer SPI DMA initialization, if SDMA module is not yet
available.
Signed-off-by: NVladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Signed-off-by: NAnton Bondarenko <anton.bondarenko.sama@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Limit SPI_LOOP mode to ECSPI controller (iMX.51, iMX53 and i.MX6) only since
there is no support in other families specific code for now.
Signed-off-by: NAnton Bondarenko <anton.bondarenko.sama@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

If controller hold in reset it's not possible to write any
register except CTRL. So all other registers must be updated
only after controller bring out from reset.
Signed-off-by: NAnton Bondarenko <anton.bondarenko.sama@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Similar to other controller type checks add check function for
IMX51. It includes IMX53 and IMX6.
Signed-off-by: NAnton Bondarenko <anton.bondarenko.sama@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

There is no need to have different watermarks levels since they are the same.
Merge them into one WML parameter.
Signed-off-by: NAnton Bondarenko <anton.bondarenko.sama@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

The overflow may happen due to rescheduling for another task and/or interrupt
if we enable SPI HW before starting RX DMA. So RX DMA enabled first to make
sure data would be read out from FIFO ASAP. TX DMA enabled next to start
filling TX FIFO with new data. And finaly SPI HW enabled to start actual
data transfer.

The risk rise in case of heavy system load and high SPI clock.
Signed-off-by: NAnton Bondarenko <anton.bondarenko.sama@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Not only TX DMA should be terminated, but RX DMA also. It's required
to avoid accidential DMA memory writes from RX DMA channel and properly
terminate transaction.
Signed-off-by: NAnton Bondarenko <anton.bondarenko.sama@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Loopback mode can be activated by setting bit LBC (LoopBack
Control) of register ECSPI_TESTREG.

Add support for it.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Fixed problem with setting spi mode 0 or 1 after setting mode 2 or 3

SPI_MODE_0 and SPI_MODE_1 requires clock low when inactive. SPI_MODE_2
and SPI_MODE_3 requires clk high when inactive.
Currently driver can just set bits in fields SCLK_PHA (SPI Clock/Data
Phase Control), SCLK_POL (SPI Clock Polarity Control),
SCLK_CTL (controls the inactive state of SCLK) ans SS_POL (SPI SS
Polarity Select) of ECSPIx_CONFIGREG register.
This patch allows driver to clear corresponding bits in these fields.
Signed-off-by: NAndrew Y. Kuksov <qxovxp@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

DMA transfers must be greater than the watermark level size. spi_imx->rx_wml
and spi_imx->tx_wml contain the watermark level in 32bit words whereas struct
spi_transfer contains the transfer len in bytes. Fix the check if DMA is
possible for a transfer accordingly. This fixes transfers with sizes between
33 and 128 bytes for which previously was claimed that DMA is possible.

Fixes: f62caccd (spi: spi-imx: add DMA support)
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: NMark Brown <broonie@kernel.org>

The platform_device_id is not modified by the driver and core uses it as
const.
Signed-off-by: NKrzysztof Kozlowski <k.kozlowski.k@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

They are used to decide if the controller can do DMA on a buffer
of a specific length and thus are needed before any transfer is attempted.

This fixes a memory leak where the SPI core uses the drivers can_dma()
callback to determine if a buffer needs to be mapped. As the watermark
levels aren't correct at that point the driver falsely claims to be able to
DMA the buffer when it fact it isn't.
After the transfer has been done the core uses the same callback to
determine if it needs to unmap the buffers. As the driver now correctly
claims to not being able to DMA the buffer the core doesn't attempt to
unmap the buffer which leaves the SGT leaking.

Fixes: f62caccd (spi: spi-imx: add DMA support)
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>
Signed-off-by: NMark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org

The fourth argument of dmaengine_prep_slave_sg needs to be of the
enumeration type dma_transfer_direction instead of dma_data_direction.
Since the used enumeration values actually stay the same, this is not
an actual issue at runtime.
Signed-off-by: NStefan Agner <stefan@agner.ch>
Signed-off-by: NMark Brown <broonie@kernel.org>

return type of wait_for_completion_timeout is unsigned long not int and
always returns >=0 , this patch adds a suitable return variable and
simplifies the return value checking as there is no < 0 case.
Signed-off-by: NNicholas Mc Guire <hofrat@osadl.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

For TKT238285 hardware issue which may cause txfifo store data twice can only
be caught on i.mx6dl, we use pio mode instead of DMA mode on i.mx6dl.

Fixes: f62caccd (spi: spi-imx: add DMA support)
Signed-off-by: NRobin Gong <b38343@freescale.com>
Signed-off-by: NMark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org

The irq number is only used inside the probe function, so there is really no
need to store it in the private structure.

Use a local 'irq' variable to hold the the irq number instead.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

A platform_driver does not need to set an owner, it will be populated by the
driver core.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>

Enable DMA support on i.mx6. The read speed can increase from 600KB/s
to 1.2MB/s on i.mx6q. You can disable or enable dma function in dts.
If not set "dma-names" in dts, spi will use PIO mode. This patch only
validate on i.mx6, not i.mx5, but encourage ones to apply this patch
on i.mx5 since they share the same IP.

Note:
  Sometime, there is a weid data in rxfifo after one full tx/rx
transfer finish by DMA on i.mx6dl, so we disable dma functhion on
i.mx6dl.
Signed-off-by: NFrank Li <Frank.Li@freescale.com>
Signed-off-by: NRobin Gong <b38343@freescale.com>
Acked-by: NMarek Vasut <marex@denx.de>
Signed-off-by: NMark Brown <broonie@kernel.org>

Currently, at module removal, one gets the following warnings:
------------[ cut here ]------------
WARNING: at drivers/clk/clk.c:780 clk_disable+0x18/0x24()
Modules linked in: spi_imx(-) [last unloaded: ev76c560]
CPU: 1 PID: 16337 Comm: rmmod Tainted: G        W    3.10.17-80548-g90191eb-dirty #33
[<80013b4c>] (unwind_backtrace+0x0/0xf8) from [<800115dc>] (show_stack+0x10/0x14)
[<800115dc>] (show_stack+0x10/0x14) from [<800257b8>] (warn_slowpath_common+0x4c/0x68)
[<800257b8>] (warn_slowpath_common+0x4c/0x68) from [<800257f0>] (warn_slowpath_null+0x1c/0x24)
[<800257f0>] (warn_slowpath_null+0x1c/0x24) from [<803f60ec>] (clk_disable+0x18/0x24)
[<803f60ec>] (clk_disable+0x18/0x24) from [<7f02c9cc>] (spi_imx_remove+0x54/0x9c [spi_imx])
[<7f02c9cc>] (spi_imx_remove+0x54/0x9c [spi_imx]) from [<8025868c>] (platform_drv_remove+0x18/0x1c)
[<8025868c>] (platform_drv_remove+0x18/0x1c) from [<80256f60>] (__device_release_driver+0x70/0xcc)
[<80256f60>] (__device_release_driver+0x70/0xcc) from [<80257770>] (driver_detach+0xcc/0xd0)
[<80257770>] (driver_detach+0xcc/0xd0) from [<80256d90>] (bus_remove_driver+0x7c/0xc0)
[<80256d90>] (bus_remove_driver+0x7c/0xc0) from [<80068668>] (SyS_delete_module+0x144/0x1f8)
[<80068668>] (SyS_delete_module+0x144/0x1f8) from [<8000e080>] (ret_fast_syscall+0x0/0x30)
---[ end trace 1f5df9ad54996300 ]---
------------[ cut here ]------------
WARNING: at drivers/clk/clk.c:780 clk_disable+0x18/0x24()
Modules linked in: spi_imx(-) [last unloaded: ev76c560]
CPU: 1 PID: 16337 Comm: rmmod Tainted: G        W    3.10.17-80548-g90191eb-dirty #33
[<80013b4c>] (unwind_backtrace+0x0/0xf8) from [<800115dc>] (show_stack+0x10/0x14)
[<800115dc>] (show_stack+0x10/0x14) from [<800257b8>] (warn_slowpath_common+0x4c/0x68)
[<800257b8>] (warn_slowpath_common+0x4c/0x68) from [<800257f0>] (warn_slowpath_null+0x1c/0x24)
[<800257f0>] (warn_slowpath_null+0x1c/0x24) from [<803f60ec>] (clk_disable+0x18/0x24)
[<803f60ec>] (clk_disable+0x18/0x24) from [<7f02c9e8>] (spi_imx_remove+0x70/0x9c [spi_imx])
[<7f02c9e8>] (spi_imx_remove+0x70/0x9c [spi_imx]) from [<8025868c>] (platform_drv_remove+0x18/0x1c)
[<8025868c>] (platform_drv_remove+0x18/0x1c) from [<80256f60>] (__device_release_driver+0x70/0xcc)
[<80256f60>] (__device_release_driver+0x70/0xcc) from [<80257770>] (driver_detach+0xcc/0xd0)
[<80257770>] (driver_detach+0xcc/0xd0) from [<80256d90>] (bus_remove_driver+0x7c/0xc0)
[<80256d90>] (bus_remove_driver+0x7c/0xc0) from [<80068668>] (SyS_delete_module+0x144/0x1f8)
[<80068668>] (SyS_delete_module+0x144/0x1f8) from [<8000e080>] (ret_fast_syscall+0x0/0x30)
---[ end trace 1f5df9ad54996301 ]---

Since commit 9e556dcc, "spi: spi-imx: only
enable the clocks when we start to transfer a message", clocks are always
disabled except when transmitting messages.  There is thus no need to
disable them at module removal.

Fixes: 9e556dcc (spi: spi-imx: only enable the clocks when we start to transfer a message)
Signed-off-by: NPhilippe De Muyter <phdm@macqel.be>
Acked-by: NHuang Shijie <b32955@freescale.com>
Signed-off-by: NMark Brown <broonie@linaro.org>
Cc: stable@vger.kernel.org

Signed-off-by: NAlexander Shiyan <shc_work@mail.ru>
Signed-off-by: NMark Brown <broonie@linaro.org>

No need to return a 'fake' return value on platform_get_irq() failure.

Just return the error code itself instead.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NMark Brown <broonie@linaro.org>

Calling init_completion() once is enough.
For the rest of the iterations, call reinit_completion() instead.
Signed-off-by: NAxel Lin <axel.lin@ingics.com>
Signed-off-by: NMark Brown <broonie@linaro.org>