Commit Graph

61 Commits

Author SHA1 Message Date
Krzysztof Kozlowski 9dbba3f87c i2c: xiic: Simplify with dev_err_probe()
Common pattern of handling deferred probe can be simplified with
dev_err_probe().  Less code and the error value gets printed.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
2021-06-23 18:22:17 +02:00
Qinglang Miao a85c5c7a3a i2c: xiic: fix reference leak when pm_runtime_get_sync fails
The PM reference count is not expected to be incremented on
return in xiic_xfer and xiic_i2c_remove.

However, pm_runtime_get_sync will increment the PM reference
count even failed. Forgetting to putting operation will result
in a reference leak here.

Replace it with pm_runtime_resume_and_get to keep usage
counter balanced.

Fixes: 10b17004a7 ("i2c: xiic: Fix the clocking across bind unbind")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
2021-04-14 09:49:26 +02:00
Jaakko Laine 9e3b184b3b i2c: xiic: Support forcing single-master in DT
I2C master operating in multimaster mode can get stuck
indefinitely if I2C start is detected on bus, but no master
has a transaction going.

This is a weakness in I2C standard, which defines no way
to recover, since all masters are indefinitely disallowed
from interrupting the currently operating master. A start
condition can be created for example by an electromagnetic
discharge applied near physical I2C lines. Or a already
operating master could get reset immediately after sending
a start.

If it is known during device tree creation that only a single
I2C master will be present on the bus, this deadlock of the
I2C bus could be avoided in the driver by ignoring the
bus_is_busy register of the xiic, since bus can never be
reserved by any other master.

This patch adds this support for detecting single-master flag
in device tree and when provided, improves I2C reliability by
ignoring the therefore unnecessary xiic bus_is_busy register.

Error can be reproduced by pulling I2C SDA -line temporarily low
by shorting it to ground, while linux I2C master is operating on
it using the xiic driver. The application using the bus will
start receiving linux error code 16: "Device or resource busy"
indefinitely:

kernel: pca953x 0-0020: failed writing register
app: Error writing file, error: 16

With multi-master disabled device will instead receive error
code 5: "I/O error" while SDA is grounded, but recover normal
operation once short is removed.

kernel: pca953x 0-0020: failed reading register
app: Error reading file, error: 5

Signed-off-by: Jaakko Laine <ext-jaakko.laine@vaisala.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
2020-08-28 09:00:00 +02:00
Jaakko Laine 9106e45cea i2c: xiic: Improve struct memory alignment
xiic_i2c struct alignment causes the struct to
take more space in memory than strictly required.
Move state -member to end of struct to get less
padding.

Signed-off-by: Jaakko Laine <ext-jaakko.laine@vaisala.com>
Suggested-by: Michal Simek <michal.simek@xilinx.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
2020-08-28 08:59:47 +02:00
Jaakko Laine 0a9336ee13 i2c: xiic: Change code alignment to 1 space only
Alignment removed and replaced with 1 space only to
reduce need for future alignment changes affecting multiple
lines, when new variables are added.

Signed-off-by: Jaakko Laine <ext-jaakko.laine@vaisala.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
2020-08-28 08:59:31 +02:00
Colin Ian King 878508aed4 i2c: xiic: fix indentation issue
There is a statement that is indented one level too deeply, remove
the extraneous tab.

Fixes: b4c119dbc3 ("i2c: xiic: Add timeout to the rx fifo wait loop")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Shubhrajyoti Datta <shubhrajyoti.datta@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2020-01-29 21:53:51 +01:00
Shubhrajyoti Datta 10b17004a7 i2c: xiic: Fix the clocking across bind unbind
The recommendation is that the set_active should be done
with pm runtime disabled.
Also fix the remove path for clocking.

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2020-01-15 21:13:40 +01:00
Venkatesh Yadav Abbarapu c9d059681b i2c: xiic: defer the probe if clock is not found
It's not always the case that clock is already available when i2c
driver get probed at the first time, e.g. the clock is provided by
clock wizard which may be probed after i2c driver. So let's defer
the probe when devm_clk_get() call fails and give it chance to
try later.

Signed-off-by: Venkatesh Yadav Abbarapu <venkatesh.abbarapu@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2020-01-15 21:13:34 +01:00
Shubhrajyoti Datta b4c119dbc3 i2c: xiic: Add timeout to the rx fifo wait loop
Add timeout to the rx fifo empty wait loop. Also check for the return
value for xiic_reinit and pass it to xiic_start_xfer.

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2020-01-15 21:13:28 +01:00
Wolfram Sang bf255befe7 i2c: xiic: convert to use i2c_new_client_device()
Move away from the deprecated API and return the shiny new ERRPTR where
useful.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2020-01-15 20:39:47 +01:00
Shubhrajyoti Datta bcc156e228 i2c: xiic: Fix kerneldoc warnings
Fix the below warning by adding the description of clock and dev.

drivers/i2c/busses/i2c-xiic.c:57: info: Scanning doc for struct xiic_i2c
drivers/i2c/busses/i2c-xiic.c:84: warning: Function parameter or member
'dev' not described in 'xiic_i2c'
drivers/i2c/busses/i2c-xiic.c:84: warning: Function parameter or member
'clk' not described in 'xiic_i2c'

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2019-11-11 20:43:07 +01:00
Robert Hancock 49b8095867 i2c: xiic: Add max_read_len quirk
This driver does not support reading more than 255 bytes at once because
the register for storing the number of bytes to read is only 8 bits. Add
a max_read_len quirk to enforce this.

This was found when using this driver with the SFP driver, which was
previously reading all 256 bytes in the SFP EEPROM in one transaction.
This caused a bunch of hard-to-debug errors in the xiic driver since the
driver/logic was treating the number of bytes to read as zero.
Rejecting transactions that aren't supported at least allows the problem
to be diagnosed more easily.

Signed-off-by: Robert Hancock <hancock@sedsystems.ca>
Reviewed-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
2019-06-08 00:24:07 +02:00
Thomas Gleixner 1802d0beec treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation this program is
  distributed in the hope that it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 655 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070034.575739538@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:41 -07:00
Shubhrajyoti Datta ae7304c3ea i2c: xiic: Make the start and the byte count write atomic
Disable interrupts while configuring the transfer and enable them back.

We have below as the programming sequence
1. start and slave address
2. byte count and stop

In some customer platform there was a lot of interrupts between 1 and 2
and after slave address (around 7 clock cyles) if 2 is not executed
then the transaction is nacked.

To fix this case make the 2 writes atomic.

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
[wsa: added a newline for better readability]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
2018-09-06 20:49:09 +02:00
Peter Rosin 30a6475744 i2c: busses: make use of i2c_8bit_addr_from_msg
Because it looks neater.

For diolan, this allows factoring out some code that is now common
between if and else.

For eg20t, pch_i2c_writebytes is always called with a write in
msgs->flags, and pch_i2c_readbytes with a read.

For imx, i2c_imx_dma_write and i2c_imx_write are always called with a
write in msgs->flags, and i2c_imx_read with a read.

For qup, qup_i2c_write_tx_fifo_v1 is always called with a write in
qup->msg->flags.

For stu300, also restructure debug output for resends, since that
code as a result is only handling debug output.

Reviewed-by: Guenter Roeck <linux@roeck-us.net> [diolan]
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> [efm32 and imx]
Acked-by: Linus Walleij <linus.walleij@linaro.org> [stu300]
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-05-29 20:30:49 +02:00
Wolfram Sang 3d8b7a4ea3 Merge branch 'i2c/platform_data-immutable' into i2c/for-4.18 2018-05-17 16:29:19 +02:00
Wolfram Sang 7072b75c15 i2c: xiic: move header to platform_data
This header only contains platform_data. Move it to the proper directory.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Lee Jones <lee.jones@linaro.org>
2018-05-17 16:27:59 +02:00
Colin Ian King 1ee7cdbfcd i2c: xiic: fix spelling mistake: "unexpexted" -> "unexpected"
Trivial fix to spelling mistakes in dev_dbg messages

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-05-17 15:51:59 +02:00
Moritz Fischer 74d23319fd i2c: xiic: Make suspend function names consistent
Suspend functions seem to have been copied from i2c-cadence driver.
Rename the functions to match the rest of the driver.

Signed-off-by: Moritz Fischer <mdf@kernel.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-03-17 21:15:12 +01:00
Bhumika Goyal 329430ccfc i2c: busses: make i2c_adapter const
Make these const as they are only used in a copy operation.
Done using Coccinelle.

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Acked-by: David Daney <david.daney@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-08-29 22:26:08 +02:00
Masahiro Yamada 9242e72aae i2c: use dev_get_drvdata() to get private data in suspend/resume hooks
Several drivers call to_platform_device() to get platform_device
and pass it to platform_get_drvdata().  In platform_get_drvdata(),
the platform_device is converted back to struct device again.

Use dev_get_drvdata() to avoid platform_device/device dance.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> (for DesignWare only)
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-07-31 17:03:32 +02:00
Wolfram Sang ea734404f3 i2c: don't print error when adding adapter fails
The core will do this for us now.

Signed-off-by: Wolfram Sang <wsa-dev@sang-engineering.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Acked-by: Peter Korsgaard <peter@korsgaard.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Acked-by: Ray Jui <ray.jui@broadcom.com>
Acked-by: Vladimir Zapolskiy <vz@mleia.com>
Acked-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Acked-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-08-22 08:19:55 +02:00
Shubhrajyoti Datta 36ecbcab84 i2c: xiic: Implement power management
Enable power management. This patch enables the clocks before transfer
and disables after the transfer. It also adds the clock description.

Signed-off-by: Shubhrajyoti Datta <shubhraj@xilinx.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-03-03 22:25:17 +01:00
Lars-Peter Clausen 77c6801967 i2c: xiic: Replace spinlock with mutex
All protected sections are only called from sleep-able context, so there is
no need to use a spinlock.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Shubhrajyoti Datta <shubhraj@xilinx.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-11-30 18:37:23 +01:00
Lars-Peter Clausen d0fe5258e6 i2c: xiic: Prevent concurrent running of the IRQ handler and __xiic_start_xfer()
Prior to commit e6c9a037bc ("i2c: xiic: Remove the disabling of
interrupts") IRQs where disabled when the initial __xiic_start_xfer() was
called. After the commit the interrupt is enabled while the function is
running, this means it is possible for the interrupt to be triggered while
the function is still running. When this happens the internal data
structures get corrupted and undefined behavior can occur like the
following crash:

	Internal error: Oops: 17 [#1] PREEMPT SMP ARM
	Modules linked in:
	CPU: 0 PID: 2040 Comm: i2cdetect Not tainted 4.0.0-02856-g047a308 #10956
	Hardware name: Xilinx Zynq Platform
	task: ee0c9500 ti: e99a2000 task.ti: e99a2000
	PC is at __xiic_start_xfer+0x6c4/0x7c8
	LR is at __xiic_start_xfer+0x690/0x7c8
	pc : [<c02bbffc>]    lr : [<c02bbfc8>]    psr: 800f0013
	sp : e99a3da8  ip : 00000000  fp : 00000000
	r10: 00000001  r9 : 600f0013  r8 : f0180000
	r7 : f0180000  r6 : c064e444  r5 : 00000017  r4 : ee031010
	r3 : 00000000  r2 : 00000000  r1 : 600f0013  r0 : 0000000f
	Flags: Nzcv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
	Control: 18c5387d  Table: 29a5404a  DAC: 00000015
	Process i2cdetect (pid: 2040, stack limit = 0xe99a2210)
	Stack: (0xe99a3da8 to 0xe99a4000)
	3da0:                   ee031010 00000000 00000001 ee031020 ee031224 c02bc5ec
	3dc0: ee34c604 00000000 ee0c9500 e99a3dcc e99a3dd0 e99a3dd0 e99a3dd8 c069f0e8
	3de0: 00000000 ee031020 c064e100 ffff90bb e99a3e48 c02b6590 ee031020 00000001
	3e00: e99a3e48 ee031020 00000000 e99a3e63 00000001 c02b6ec4 00000000 00000000
	3e20: 00000000 c02b7320 e99a3ef0 00000000 00000000 e99e3df0 00000000 00000000
	3e40: 00000103 2814575f 0000003e c00a0000 e99a3e85 0001003e ee0c0000 e99a3e63
	3e60: eefd3578 c064e61c ee0c9500 c0041e04 0000056c e9a56db8 00006e5a b6f5c000
	3e80: ee0c9548 eefd0040 00000001 eefd3540 ee0c9500 eefd39a0 c064b540 ee0c9500
	3ea0: 00000000 ee92b000 00000000 bef4862c ee34c600 e99ecdc0 00000720 00000003
	3ec0: e99a2000 00000000 00000000 c02b8b30 00000000 00000000 00000000 e99a3f24
	3ee0: b6e80000 00000000 00000000 c04257e8 00000000 e99a3f24 c02b8f08 00000703
	3f00: 00000003 c02116bc ee935300 00000000 bef4862c ee34c600 e99ecdc0 c02b91f0
	3f20: e99ecdc0 00000720 bef4862c eeb725f8 e99ecdc0 c00c9e2c 00000003 00000003
	3f40: ee248dc0 00000000 ee248dc8 00000002 eeb7c1a8 00000000 00000000 c00bb360
	3f60: 00000000 00000000 00000003 ee248dc0 bef4862c e99ecdc0 e99ecdc0 00000720
	3f80: 00000003 e99a2000 00000000 c00c9f68 00000000 00000000 b6f22000 00000036
	3fa0: c000dfa4 c000de20 00000000 00000000 00000003 00000720 bef4862c bef4862c
	3fc0: 00000000 00000000 b6f22000 00000036 00000000 00000000 b6f60000 00000000
	3fe0: 00013040 bef48614 00008cab b6ecdbe6 400f0030 00000003 2f7fd821 2f7fdc21
	[<c02bbffc>] (__xiic_start_xfer) from [<c02bc5ec>] (xiic_xfer+0x94/0x168)
	[<c02bc5ec>] (xiic_xfer) from [<c02b6590>] (__i2c_transfer+0x4c/0x7c)
	[<c02b6590>] (__i2c_transfer) from [<c02b6ec4>] (i2c_transfer+0x9c/0xc4)
	[<c02b6ec4>] (i2c_transfer) from [<c02b7320>] (i2c_smbus_xfer+0x3a0/0x4ec)
	[<c02b7320>] (i2c_smbus_xfer) from [<c02b8b30>] (i2cdev_ioctl_smbus+0xb0/0x214)
	[<c02b8b30>] (i2cdev_ioctl_smbus) from [<c02b91f0>] (i2cdev_ioctl+0xa0/0x1d4)
	[<c02b91f0>] (i2cdev_ioctl) from [<c00c9e2c>] (do_vfs_ioctl+0x4b0/0x5b8)
	[<c00c9e2c>] (do_vfs_ioctl) from [<c00c9f68>] (SyS_ioctl+0x34/0x5c)
	[<c00c9f68>] (SyS_ioctl) from [<c000de20>] (ret_fast_syscall+0x0/0x34)
	Code: e283300c e5843210 eafffe64 e5943210 (e1d320b4)

The issue can easily be reproduced by performing I2C access under high
system load or IO load.

To fix the issue protect the invocation to __xiic_start_xfer() form
xiic_start_xfer() with the same lock that is used to protect the interrupt
handler.

Fixes: e6c9a037bc ("i2c: xiic: Remove the disabling of interrupts")
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Shubhrajyoti Datta <shubhraj@xilinx.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-11-20 16:15:35 +01:00
Lars-Peter Clausen 9656eeebf3 i2c: Revert "i2c: xiic: Do not reset controller before every transfer"
Commit d701667bb3 ("i2c: xiic: Do not reset controller before every
transfer") removed the reinitialization of the controller before the start
of each transfer. Apparently this change is not safe to make and the commit
results in random I2C bus failures.

An easy way to trigger the issue is to run i2cdetect.

Without the patch applied:
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
	 00:          -- -- -- -- -- -- -- -- -- -- -- -- --
	 10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
	 20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
	 30: -- -- -- -- -- -- -- -- UU UU -- UU 3c -- -- UU
	 40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
	 50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
	 60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
	 70: -- -- -- -- -- -- -- --

With the patch applied every other or so invocation:
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
	 00:          03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f
	 10: 10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f
	 20: 20 21 22 23 24 25 26 27 28 29 2a 2b 2c 2d 2e 2f
	 30: -- -- -- -- -- -- -- -- UU UU -- UU 3c -- -- UU
	 40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
	 50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
	 60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
	 70: -- -- -- -- -- -- -- --

So revert the commit for now.

Fixes: d701667bb3 ("i2c: xiic: Do not reset controller before every transfer")
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Shubhrajyoti Datta <shubhraj@xilinx.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-11-20 16:04:59 +01:00
Shubhrajyoti Datta 6b0c8dc310 i2c: xiic: Do not continue in case of errors in Rx
In case of error conditions like Arbitration lost or NACK lets signal
the waiting process.

Handle error cases in the Rx path

Signed-off-by: Shubhrajyoti Datta <shubhraj@xilinx.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-08-10 08:37:33 +02:00
Shubhrajyoti Datta 7f9906bd7f i2c: xiic: Service all interrupts in isr
Currently only one interrupt is serviced in the isr.
In case the multiple interrupts happen simultenously we service and ack
only one of them. Check for all the causes in the isr and service them.

Signed-off-by: Shubhrajyoti Datta <shubhraj@xilinx.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-08-10 08:37:32 +02:00
Shubhrajyoti Datta 542e2a9b73 i2c: xiic: Remove the Addressed as slave interrupt
Currently there is no slave mode support in the driver
also in the isr we just ack it and do nothing.
So disable the AAS interrupt.

Signed-off-by: Shubhrajyoti Datta <shubhraj@xilinx.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-08-10 08:37:32 +02:00
Shubhrajyoti Datta b33aa25278 i2c: xiic: Remove busy loop while waiting for bus busy
Remove the busy loop  while waiting for bus busy.
Instead let the processor sleep.

Signed-off-by: Shubhrajyoti Datta <shubhraj@xilinx.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-08-10 08:37:32 +02:00
Shubhrajyoti Datta e6c9a037bc i2c: xiic: Remove the disabling of interrupts
Currently before every transfer the interrupts are disabled.
So incase the slave nacks in the middle of the transfer the
current transfer is not aborted. Upon enabling the interrupts
conditions like NACK , arbitration lost will not be masked.
Remove the disabling of the interrupts.

Signed-off-by: Shubhrajyoti Datta <shubhraj@xilinx.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-08-10 08:37:32 +02:00
Shubhrajyoti Datta d701667bb3 i2c: xiic: Do not reset controller before every transfer
Currently before every transfer the controller is reinitialised.
We are already resetting the controller upon errors so upon every
transfer is a performance kill.
Remove the same.

Signed-off-by: Shubhrajyoti Datta <shubhraj@xilinx.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-08-10 08:37:31 +02:00
Shubhrajyoti Datta fcc2fac60a i2c: xiic: move the xiic_process to thread context
The xiic_process is a 154 line code that runs in isr context currently
move it to thread context. Also the name xiic_process suggests that the
intension was to run in process context.

Signed-off-by: Shubhrajyoti Datta <shubhraj@xilinx.com>
[wsa: initialized irqreturn_t to IRQ_NONE instead of IRQ_HANDLED]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-08-10 08:37:31 +02:00
Shubhrajyoti Datta 0387fc1645 i2c: xiic: Remove the disabling of interrupts
Currently the interrupts are disabled at the start of the
isr and enabled at the end of the isr. Remove the same.

In case the slave device NACKs the transaction while in the isr
the transfer will continue and the NACK interrupt will arrive
only after the isr is serviced.

Signed-off-by: Shubhrajyoti Datta <shubhraj@xilinx.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-08-10 08:37:31 +02:00
Shubhrajyoti Datta bea6ff020f i2c: xiic: Fix kerneldoc warnings
info(drivers/i2c/busses/i2c-xiic.c:55): Scanning doc for struct xiic_i2c
Warning(drivers/i2c/busses/i2c-xiic.c:79): No description found for parameter 'endianness'

Signed-off-by: Shubhrajyoti Datta <shubhraj@xilinx.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-05-12 15:18:27 +02:00
Linus Torvalds e6b5be2be4 Driver core patches for 3.19-rc1
Here's the set of driver core patches for 3.19-rc1.
 
 They are dominated by the removal of the .owner field in platform
 drivers.  They touch a lot of files, but they are "simple" changes, just
 removing a line in a structure.
 
 Other than that, a few minor driver core and debugfs changes.  There are
 some ath9k patches coming in through this tree that have been acked by
 the wireless maintainers as they relied on the debugfs changes.
 
 Everything has been in linux-next for a while.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core update from Greg KH:
 "Here's the set of driver core patches for 3.19-rc1.

  They are dominated by the removal of the .owner field in platform
  drivers.  They touch a lot of files, but they are "simple" changes,
  just removing a line in a structure.

  Other than that, a few minor driver core and debugfs changes.  There
  are some ath9k patches coming in through this tree that have been
  acked by the wireless maintainers as they relied on the debugfs
  changes.

  Everything has been in linux-next for a while"

* tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (324 commits)
  Revert "ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries"
  fs: debugfs: add forward declaration for struct device type
  firmware class: Deletion of an unnecessary check before the function call "vunmap"
  firmware loader: fix hung task warning dump
  devcoredump: provide a one-way disable function
  device: Add dev_<level>_once variants
  ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries
  ath: use seq_file api for ath9k debugfs files
  debugfs: add helper function to create device related seq_file
  drivers/base: cacheinfo: remove noisy error boot message
  Revert "core: platform: add warning if driver has no owner"
  drivers: base: support cpu cache information interface to userspace via sysfs
  drivers: base: add cpu_device_create to support per-cpu devices
  topology: replace custom attribute macros with standard DEVICE_ATTR*
  cpumask: factor out show_cpumap into separate helper function
  driver core: Fix unbalanced device reference in drivers_probe
  driver core: fix race with userland in device_add()
  sysfs/kernfs: make read requests on pre-alloc files use the buffer.
  sysfs/kernfs: allow attributes to request write buffer be pre-allocated.
  fs: sysfs: return EGBIG on write if offset is larger than file size
  ...
2014-12-14 16:10:09 -08:00
Thomas Gessler 48ef3ca98d i2c: xiic: Fix big-endian register access
The driver tried to access device registers with the (little-endian)
iowrite/ioread functions. While this worked on little-endian machines
(e.g. Microblaze with AXI bus), it made the driver unusable on
big-endian machines (e.g. PPC405 with PLB).

During the probe function, the driver tried to write a 32-bit reset mask
into the reset register. This caused an error interrupt on big-endian
systems, because the device detected an invalid (byte-swapped) reset
mask. The result was an Oops.

The patch implements an endianness detection similar to the one used in
other Xilinx drivers like drivers/spi/spi-xilinx.c. It was tested on a
PPC405/PLB system.

Signed-off-by: Thomas Gessler <Thomas.Gessler@exp2.physik.uni-giessen.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-11-17 19:54:23 +01:00
Wolfram Sang ca1f8da9ac i2c: remove FSF address
We have a central copy of the GPL for that. Some addresses were already
outdated.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
2014-11-07 18:35:33 +01:00
Wolfram Sang 1ecc4335eb i2c: busses: 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 16:20:37 +02:00
Wolfram Sang 4db5beed9c i2c: i2c-xiic: Drop class based scanning to improve bootup time
This driver has been flagged to drop class based instantiation. The removal
improves boot-up time and is unneeded for embedded controllers. Users have been
warned to switch for some time now, so we can actually do the removal. Keep the
DEPRECATED flag, so the core can inform users that the behaviour finally
changed now. After another transition period, this flag can go, too.
While we are here, remove the indentation for the array setup because
such things always break after some time.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-07-16 23:00:08 +02:00
Wolfram Sang a9965d73fd i2c: i2c-xiic: deprecate class based instantiation
Warn users that class based instantiation is going away soon in favour
of more robust probing and faster bootup times.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-03-28 08:55:04 +01:00
Paul Gortmaker 21d0b7c0fa i2c: 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>
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-01-24 18:24:31 +01:00
Kedareswara rao Appana 168e722dcb i2c: xilinx: Use devm_* functions
Simplified the probe and remove functions using devm_* functions

Signed-off-by: Kedareswara rao Appana <appanad@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-01-04 23:35:02 +01:00
Michal Simek 617bdcbc3c i2c: xilinx: Do not enable irq before irq handler
IRQ handler has to be register first before IRQ
is enabled in xiic_reinit().

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-01-04 23:34:29 +01:00
Kedareswara rao Appana f1e9f89aa9 i2c: xilinx: Fix i2c checkpatch warnings
Code changes to fix checkpatch warnings listed below.
- WARNING: please, no space before tabs
- WARNING: quoted string split across lines

Signed-off-by: Kedareswara rao Appana <appanad@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-01-04 23:33:52 +01:00
Sachin Kamat 4edd65e63f i2c: Include linux/of.h header
'of_match_ptr' is defined in linux/of.h. Include it explicitly to
avoid build breakage in the future.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-10-30 16:46:30 +01:00
Jingoo Han ab0dc7a81d i2c: xiic: Remove casting the return value which is a void pointer
Casting the return value which is a void pointer is redundant.
The conversion from void pointer to any other pointer type is
guaranteed by the C programming language.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-09-30 06:02:33 +02:00
Wolfram Sang 687b81d083 i2c: move OF helpers into the core
I2C of helpers used to live in of_i2c.c but experience (from SPI) shows
that it is much cleaner to have this in the core. This also removes a
circular dependency between the helpers and the core, and so we can
finally register child nodes in the core instead of doing this manually
in each driver. So, fix the drivers and documentation, too.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-08-23 10:22:20 +02:00
Jingoo Han 6d4028c644 i2c: use dev_get_platdata()
Use the wrapper function for retrieving the platform data instead of
accessing dev->platform_data directly.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-08-19 19:46:30 +02:00
Steven A. Falco c39e8e4354 i2c: xiic: must always write 16-bit words to TX_FIFO
The TX_FIFO register is 10 bits wide.  The lower 8 bits are the data to be
written, while the upper two bits are flags to indicate stop/start.

The driver apparently attempted to optimize write access, by only writing a
byte in those cases where the stop/start bits are zero.  However, we have
seen cases where the lower byte is duplicated onto the upper byte by the
hardware, which causes inadvertent stop/starts.

This patch changes the write access to the transmit FIFO to always be 16 bits
wide.

Signed off by: Steven A. Falco <sfalco@harris.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
2013-04-23 20:18:34 +02:00