Commit Graph

81 Commits

Author SHA1 Message Date
Sascha Hauer
6b6192c04b spi: imx: drop bogus tests for rx/tx bufs in DMA transfer
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: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-02-26 11:04:14 +09:00
Sascha Hauer
b03c3884ca spi: imx: set MX51_ECSPI_CTRL_SMC bit in setup function
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: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-02-26 11:04:14 +09:00
Sascha Hauer
d629c2a005 spi: imx: make some register defines simpler
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: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-02-26 11:04:14 +09:00
Sascha Hauer
c34de7168c spi: imx: remove unnecessary bit clearing in mx51_ecspi_config
This reverts patch 1476253cef (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: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-02-26 11:04:14 +09:00
Anton Bondarenko
f12ae171c7 spi: imx: add support for all SPI word width for DMA
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: Anton Bondarenko <anton.bondarenko.sama@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-02-26 11:04:14 +09:00
Sascha Hauer
882f329f31 spi: imx: drop unncessary dma_is_inited variable
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: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-02-26 11:04:14 +09:00
Sascha Hauer
2b0fd069ec spi: imx: drop unnecessary read/modify/write
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: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-02-26 11:04:14 +09:00
Sascha Hauer
c008a80071 spi: imx: initialize usedma earlier
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: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-02-26 11:04:14 +09:00
Sascha Hauer
99f1cf1c0c spi: imx: drop fallback to PIO
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: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-02-24 17:30:08 +09:00
Anton Bondarenko
4bfe927a11 spi: imx: replace fixed timeout with calculated
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: Anton Bondarenko <anton.bondarenko.sama@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-02-20 00:50:47 +09:00
Mark Brown
a4e5efc0d2 Merge remote-tracking branch 'spi/fix/imx' into spi-imx 2016-02-20 00:49:12 +09:00
Mark Brown
499e49b6d3 spi: Fixes for v4.5
A small clutch of driver specific fixes.  The OMAP one is a bit worrying
 since it seems to be triggered by some changes in the runtime PM core
 code and I suspect there's other drivers across that are going to be
 using the same pattern outside of OMAP but nothing seems to be coming up
 in the testing people are doing.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQEcBAABAgAGBQJWwcN2AAoJECTWi3JdVIfQM9IH/2WWGIU4ByQeHLd7FnNHQwZk
 wh4g7xpo/SRzob2rz2yqeKgkIg4Ew4+BsD5jslvGhBn9ph5HIFYHVcHt3vjVUNRE
 EyOoM8X4lLc97LYog10ieXk5dFkvcCTDYoQDcTxVDmMPRsRrt2Z7htTB4jAbhlk/
 kH5nJCir4Cwk5qDTw7+9W8d5hCXl3ESM7KoTCqtvpA8JmTD++vRcphp39NWZejAw
 ukO/EAJcwqlTmds3zki1/lM6R4NBtbAE2BGy9j0eUQnL3/37Sl77hAxcsKjey1Zj
 dVa8ow9ZRTEZtbCQjrK8WpD3V26TNuUGZs4qEQ+nizQnvAnrqgkfOOg6wBJ6LDg=
 =imJW
 -----END PGP SIGNATURE-----

Merge tag 'spi-fix-v4.5-rc4' into spi-imx

spi: Fixes for v4.5

A small clutch of driver specific fixes.  The OMAP one is a bit worrying
since it seems to be triggered by some changes in the runtime PM core
code and I suspect there's other drivers across that are going to be
using the same pattern outside of OMAP but nothing seems to be coming up
in the testing people are doing.
2016-02-18 14:10:59 +00:00
Sascha Hauer
6aa800ca65 spi: imx: use proper dev_* functions for driver messages
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: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-02-17 14:22:56 +00:00
Anton Bondarenko
390f0ffe92 spi: imx: allow only WML aligned transfers to use DMA
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 f6ee9b582d
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: Anton Bondarenko <anton.bondarenko.sama@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-02-17 14:22:29 +00:00
Gao Pan
f8efca2f17 spi: imx: fix spi resource leak with dma transfer
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: Gao Pan <pandy.gao@nxp.com>
Reviewed-by: Fugang Duan <B38611@freescale.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2016-01-22 16:46:58 +00:00
Anton Bondarenko
bf9af08cd5 spi: imx: defer spi initialization, if DMA engine is
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: Anton Bondarenko <anton.bondarenko.sama@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-12-15 22:40:35 +00:00
Anton Bondarenko
3760047a7d spi: imx: return error from dma channel request
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: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Signed-off-by: Anton Bondarenko <anton.bondarenko.sama@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-12-15 22:40:35 +00:00
Anton Bondarenko
4686d1c3d1 spi: imx: enable loopback only for ECSPI controller family
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: Anton Bondarenko <anton.bondarenko.sama@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-12-15 22:40:35 +00:00
Anton Bondarenko
f677f17cce spi: imx: fix loopback mode setup after controller reset
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: Anton Bondarenko <anton.bondarenko.sama@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-12-15 22:40:35 +00:00
Anton Bondarenko
f8a876176f spi: imx: add function to check for IMX51 family controller
Similar to other controller type checks add check function for
IMX51. It includes IMX53 and IMX6.

Signed-off-by: Anton Bondarenko <anton.bondarenko.sama@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-12-07 19:53:35 +00:00
Anton Bondarenko
0dfbaa8932 spi: imx: replace multiple watermarks with single for RX, TX and RXT
There is no need to have different watermarks levels since they are the same.
Merge them into one WML parameter.

Signed-off-by: Anton Bondarenko <anton.bondarenko.sama@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-12-07 19:53:35 +00:00
Anton Bondarenko
fab44ef1ad spi: imx: reorder HW operations enable order to avoid possible RX data loss
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: Anton Bondarenko <anton.bondarenko.sama@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-12-07 19:53:35 +00:00
Anton Bondarenko
e47b33c076 spi: imx: terminate RX DMA transaction in case of TX DMA timeout
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: Anton Bondarenko <anton.bondarenko.sama@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-12-07 19:53:35 +00:00
Fabio Estevam
9f6aa42bbb spi: imx: Add loopback mode support
Loopback mode can be activated by setting bit LBC (LoopBack
Control) of register ECSPI_TESTREG.

Add support for it.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-12-04 12:13:02 +00:00
Andrew Y. Kuksov
1476253cef spi: imx: fix ecspi mode setup
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: Andrew Y. Kuksov <qxovxp@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-10-23 02:07:52 +09:00
Sascha Hauer
f6ee9b582d spi: imx: Fix small DMA transfers
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: f62caccd12 (spi: spi-imx: add DMA support)
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-07-24 16:08:55 +01:00
Krzysztof Kozlowski
db1b8200e0 spi: imx: Constify platform_device_id
The platform_device_id is not modified by the driver and core uses it as
const.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-05-01 17:37:26 +01:00
Mark Brown
35fbf8452c Merge remote-tracking branches 'spi/topic/fsl-cspi', 'spi/topic/fsl-dspi', 'spi/topic/imx' and 'spi/topic/of-id' into spi-next 2015-04-11 23:09:14 +01:00
Lucas Stach
f511ab09df spi: imx: read back the RX/TX watermark levels earlier
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: f62caccd12 (spi: spi-imx: add DMA support)
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
2015-04-01 21:32:38 +01:00
Stefan Agner
e8361f70a8 spi: spi-imx: use correct enumeration type
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: Stefan Agner <stefan@agner.ch>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-03-03 09:58:24 +00:00
Mark Brown
8328509c4b Merge remote-tracking branches 'spi/topic/img-spfi', 'spi/topic/imx', 'spi/topic/inline', 'spi/topic/meson' and 'spi/topic/mxs' into spi-next 2015-02-08 11:16:52 +08:00
Nicholas Mc Guire
56536a7ff5 spi: spi-imx: cleanup wait_for_completion handling
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: Nicholas Mc Guire <hofrat@osadl.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-02-04 20:53:15 +00:00
Robin Gong
a02bb401f8 spi: imx: use pio mode for i.mx6dl
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: f62caccd12 (spi: spi-imx: add DMA support)
Signed-off-by: Robin Gong <b38343@freescale.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
2015-02-03 12:17:01 +00:00
Fabio Estevam
4b5d6aadce spi: spi-imx: Do not store the irq number in the private structure
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: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2014-12-30 11:25:06 +00:00
Wolfram Sang
14ac00e033 spi: drop owner assignment from platform_drivers
A platform_driver does not need to set an owner, it will be populated by the
driver core.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-10-20 16:21:36 +02:00
Robin Gong
f62caccd12 spi: spi-imx: add DMA support
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: Frank Li <Frank.Li@freescale.com>
Signed-off-by: Robin Gong <b38343@freescale.com>
Acked-by: Marek Vasut <marex@denx.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
2014-09-17 11:36:11 -07:00
Mark Brown
6e07b9179a Merge remote-tracking branches 'spi/topic/imx', 'spi/topic/init', 'spi/topic/mpc512x-psc', 'spi/topic/mpc52xx', 'spi/topic/mxs', 'spi/topic/nuc900', 'spi/topic/oc-tiny' and 'spi/topic/octeon' into spi-next 2014-03-30 00:51:17 +00:00
Mark Brown
9dee279b40 Merge remote-tracking branches 'spi/topic/bus-num', 'spi/topic/cleanup', 'spi/topic/clps711x', 'spi/topic/coldfire', 'spi/topic/completion' and 'spi/topic/davinci' into spi-next 2014-03-30 00:51:03 +00:00
Philippe De Muyter
fd40dccb1a spi: spi-imx: spi_imx_remove: do not disable disabled clocks
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 9e556dcc55, "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: 9e556dcc55 (spi: spi-imx: only enable the clocks when we start to transfer a message)
Signed-off-by: Philippe De Muyter <phdm@macqel.be>
Acked-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Cc: stable@vger.kernel.org
2014-02-28 15:14:54 +09:00
Alexander Shiyan
8fc39b5166 spi/imx: Use dev_name() for request_irq() to distinguish SPIs
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-02-23 10:46:24 +09:00
Fabio Estevam
82106e0e39 spi: spi-imx: Propagate the real error code on platform_get_irq() failure
No need to return a 'fake' return value on platform_get_irq() failure.

Just return the error code itself instead.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-02-14 20:41:37 +00:00
Axel Lin
aa0fe82629 spi: Use reinit_completion at appropriate places
Calling init_completion() once is enough.
For the rest of the iterations, call reinit_completion() instead.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-02-10 12:32:16 +00:00
Paul Gortmaker
3a44623d5e spi: delete non-required instances of include <linux/init.h>
None of these files are actually using any __init type directives
and hence don't need to include <linux/init.h>.  Most are just a
left over from __devinit and __cpuinit removal, or simply due to
code getting copied from one driver to the next.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-02-03 12:20:35 +00:00
Marek Vasut
6fd8b8503a spi: spi-imx: Fix out-of-order CS/SCLK operation at low speeds
Problem:
--------
 The problem this patch addresses has the following assumptions about the
 SPI bus setup:
 - The hardware used to find this is Freescale i.MX537 @ 1200MHz
 - The SPI SCLK operate at very low speed, less than 200 kHz
 - There are two SPI devices attached to the bus
   - Each device uses different GPIO for chipselect
   - Each device requires different SCLK signal polarity

 The observation of the SCLK and GPIO chipselect lines with a logic analyzer
 shows, that the SCLK polarity change does sometimes happen after the GPIO
 chipselect is asserted. The SPI slave device reacts on that by counting the
 SCLK polarity change as a clock pulse, which disrupts the communication with
 the SPI slave device.

Explanation:
------------
 We found an interesting correlation, that the maximum delay between the write
 into the ECSPIx_CONFIGREG register and the change of SCLK polarity at each
 SCLK frequency of 10 kHz, 20 kHz, 50 kHz and 100 kHz is 100 uS, 50 uS, 20 uS
 and 10 uS respectively. This lead us to a theory, that at SCLK frequency of
 1 Hz, the delay would be 1 S. Therefore, the time it takes for the write to
 ECSPIx_CONFIGREG to take effect in the hardware is up to the duration of 1
 tick of the SCLK clock.

 During this delay period, if the SCLK frequency is too low, the execution of
 the spi-imx.c driver can advance so much, that the GPIO chipselect will be
 asserted. The GPIO chipselect is asserted almost immediatelly.

Solution:
---------
 The solution this patch presents is simple. We calculate the resulting SCLK
 clock first by dividing the ECSPI block clock by both dividers that are to be
 programmed into the configuration register. Based on the resulting SCLK clock,
 we derive the delay it will take for the changes to get really applied. We are
 extra careful here so we delay twice as long as we should. Note that the patch
 does not create additional overhead at high speeds as the delay will likely be
 close to zero there.

Signed-off-by: Marek Vasut <marex@denx.de>
To: linux-spi@vger.kernel.org
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Huang Shijie <b32955@freescale.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
2013-12-20 11:53:57 +00:00
Mark Brown
c25b2c9eb3 Merge remote-tracking branch 'spi/topic/imx' into spi-next 2013-10-25 09:51:29 +01:00
Huang Shijie
9e556dcc55 spi: spi-imx: only enable the clocks when we start to transfer a message
Current code keeps the clocks enabled all the time, it wastes the power
when there is no operaiton on the spi controller.

In order to save the power, this patch adds the two hooks:
   spi_imx_prepare_message: enable the clocks for this message
   spi_imx_unprepare_message: disable the clocks.

This patch also disables the clocks in the end of the probe.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
2013-10-23 10:05:05 +01:00
Axel Lin
94c69f765f spi: bitbang: Let spi_bitbang_start() take a reference to master
Many drivers that use bitbang library have a leak on probe error paths.
This is because once a spi_master_get() call succeeds, we need an additional
spi_master_put() call to free the memory.

Fix this issue by moving the code taking a reference to master to
spi_bitbang_start(), so spi_bitbang_start() will take a reference to master on
success. With this change, the caller is responsible for calling
spi_bitbang_stop() to decrement the reference and spi_master_put() as
counterpart of spi_alloc_master() to prevent a memory leak.

So now we have below patten for drivers using bitbang library:

probe:
spi_alloc_master        -> Init reference count to 1
spi_bitbang_start       -> Increment reference count
remove:
spi_bitbang_stop        -> Decrement reference count
spi_master_put          -> Decrement reference count (reference count reaches 0)

Fixup all users accordingly.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Suggested-by: Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>
Acked-by: Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>
Signed-off-by: Mark Brown <broonie@linaro.org>
2013-09-17 12:56:14 +01:00
Niels de Vos
27743e0bfd spi/imx: expose module alias for loading from device-tree
Enable auto loading by udev when spi-imx is compiled as a module.

Signed-off-by: Niels de Vos <ndevos@redhat.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
2013-07-29 12:40:08 +01:00
Fabio Estevam
83174626cc spi: spi-imx: Check the return value from clk_prepare_enable()
clk_prepare_enable() may fail, so let's check its return value and propagate it
in the case of error.

While at it, fix the order of clk_disable_unprepare calls: clk_ipg should be
disabled first, followed by clk_per.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
2013-07-15 11:37:56 +01:00
Fabio Estevam
130b82c047 spi: spi-imx: Use devm functions
Using devm functions can make the code smaller and cleaner.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
2013-07-15 11:37:56 +01:00