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* i2c: core: fix NULL pointer dereference under race conditionVladimir Zapolskiy2016-11-041-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Race condition between registering an I2C device driver and deregistering an I2C adapter device which is assumed to manage that I2C device may lead to a NULL pointer dereference due to the uninitialized list head of driver clients. The root cause of the issue is that the I2C bus may know about the registered device driver and thus it is matched by bus_for_each_drv(), but the list of clients is not initialized and commonly it is NULL, because I2C device drivers define struct i2c_driver as static and clients field is expected to be initialized by I2C core: i2c_register_driver() i2c_del_adapter() driver_register() ... bus_add_driver() ... ... bus_for_each_drv(..., __process_removed_adapter) ... i2c_do_del_adapter() ... list_for_each_entry_safe(..., &driver->clients, ...) INIT_LIST_HEAD(&driver->clients); To solve the problem it is sufficient to do clients list head initialization before calling driver_register(). The problem was found while using an I2C device driver with a sluggish registration routine on a bus provided by a physically detachable I2C master controller, but practically the oops may be reproduced under the race between arbitraty I2C device driver registration and managing I2C bus device removal e.g. by unbinding the latter over sysfs: % echo 21a4000.i2c > /sys/bus/platform/drivers/imx-i2c/unbind Unable to handle kernel NULL pointer dereference at virtual address 00000000 Internal error: Oops: 17 [#1] SMP ARM CPU: 2 PID: 533 Comm: sh Not tainted 4.9.0-rc3+ #61 Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree) task: e5ada400 task.stack: e4936000 PC is at i2c_do_del_adapter+0x20/0xcc LR is at __process_removed_adapter+0x14/0x1c Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 10c5387d Table: 35bd004a DAC: 00000051 Process sh (pid: 533, stack limit = 0xe4936210) Stack: (0xe4937d28 to 0xe4938000) Backtrace: [<c0667be0>] (i2c_do_del_adapter) from [<c0667cc0>] (__process_removed_adapter+0x14/0x1c) [<c0667cac>] (__process_removed_adapter) from [<c0516998>] (bus_for_each_drv+0x6c/0xa0) [<c051692c>] (bus_for_each_drv) from [<c06685ec>] (i2c_del_adapter+0xbc/0x284) [<c0668530>] (i2c_del_adapter) from [<bf0110ec>] (i2c_imx_remove+0x44/0x164 [i2c_imx]) [<bf0110a8>] (i2c_imx_remove [i2c_imx]) from [<c051a838>] (platform_drv_remove+0x2c/0x44) [<c051a80c>] (platform_drv_remove) from [<c05183d8>] (__device_release_driver+0x90/0x12c) [<c0518348>] (__device_release_driver) from [<c051849c>] (device_release_driver+0x28/0x34) [<c0518474>] (device_release_driver) from [<c0517150>] (unbind_store+0x80/0x104) [<c05170d0>] (unbind_store) from [<c0516520>] (drv_attr_store+0x28/0x34) [<c05164f8>] (drv_attr_store) from [<c0298acc>] (sysfs_kf_write+0x50/0x54) [<c0298a7c>] (sysfs_kf_write) from [<c029801c>] (kernfs_fop_write+0x100/0x214) [<c0297f1c>] (kernfs_fop_write) from [<c0220130>] (__vfs_write+0x34/0x120) [<c02200fc>] (__vfs_write) from [<c0221088>] (vfs_write+0xa8/0x170) [<c0220fe0>] (vfs_write) from [<c0221e74>] (SyS_write+0x4c/0xa8) [<c0221e28>] (SyS_write) from [<c0108a20>] (ret_fast_syscall+0x0/0x1c) Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Cc: stable@kernel.org
* i2c: imx: defer probe if bus recovery GPIOs are not readyStefan Agner2016-10-251-4/+7
| | | | | | | | | | | | | | Some SoC might load the GPIO driver after the I2C driver and using the I2C bus recovery mechanism via GPIOs. In this case it is crucial to defer probing if the GPIO request functions do so, otherwise the I2C driver gets loaded without recovery mechanisms enabled. Signed-off-by: Stefan Agner <stefan@agner.ch> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Li Yang <leoyang.li@nxp.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Cc: stable@kernel.org
* i2c: designware: Avoid aborted transfers with fast reacting I2C slavesJarkko Nikula2016-10-251-3/+14
| | | | | | | | | | | | | | | | | | | | I2C DesignWare may abort transfer with arbitration lost if I2C slave pulls SDA down quickly after falling edge of SCL. Reason for this is unknown but after trial and error it was found this can be avoided by enabling non-zero SDA RX hold time for the receiver. By the specification SDA RX hold time extends incoming SDA low to high transition by n * ic_clk cycles but only when SCL is high. However it seems to help avoid above faulty arbitration lost error. Bits 23:16 in IC_SDA_HOLD register define the SDA RX hold time for the receiver. Be conservative and enable 1 ic_clk cycle long hold time in case boot firmware hasn't set it up. Reported-by: Jukka Laitinen <jukka.laitinen@intel.com> Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Tested-by: Jukka Laitinen <jukka.laitinen@intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* i2c: i801: Fix I2C Block Read on 8-Series/C220 and laterJean Delvare2016-10-251-3/+13
| | | | | | | | | | | | | | | | | | | | Starting with the 8-Series/C220 PCH (Lynx Point), the SMBus controller includes a SPD EEPROM protection mechanism. Once the SPD Write Disable bit is set, only reads are allowed to slave addresses 0x50-0x57. However the legacy implementation of I2C Block Read since the ICH5 looks like a write, and is therefore blocked by the SPD protection mechanism. This causes the eeprom and at24 drivers to fail. So assume that I2C Block Read is implemented as an actual read on these chipsets. I tested it on my Q87 chipset and it seems to work just fine. Signed-off-by: Jean Delvare <jdelvare@suse.de> Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> [wsa: rebased to v4.9-rc2] Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* i2c: xgene: Avoid dma_buffer overrunHoan Tran2016-10-251-1/+1
| | | | | | | | | | SMBus block command uses the first byte of buffer for the data length. The dma_buffer should be increased by 1 to avoid the overrun issue. Reported-by: Phil Endecott <phil_gjouf_endecott@chezphil.org> Signed-off-by: Hoan Tran <hotran@apm.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Cc: stable@kernel.org
* i2c: digicolor: Fix module autoloadJavier Martinez Canillas2016-10-251-0/+1
| | | | | | | | | | | | If the driver is built as a module, autoload won't work because the module alias information is not filled. So user-space can't match the registered device with the corresponding module. Export the module alias information using the MODULE_DEVICE_TABLE() macro. Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com> Acked-by: Baruch Siach <baruch@tkos.co.il> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* i2c: xlr: Fix module autoload for OF registrationJavier Martinez Canillas2016-10-251-0/+1
| | | | | | | | | | | If the driver is built as a module, autoload won't work because the module alias information is not filled. So user-space can't match the registered device with the corresponding module. Export the module alias information using the MODULE_DEVICE_TABLE() macro. Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* i2c: xlp9xx: Fix module autoloadJavier Martinez Canillas2016-10-251-0/+1
| | | | | | | | | | | If the driver is built as a module, autoload won't work because the module alias information is not filled. So user-space can't match the registered device with the corresponding module. Export the module alias information using the MODULE_DEVICE_TABLE() macro. Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* i2c: jz4780: Fix module autoloadJavier Martinez Canillas2016-10-251-0/+1
| | | | | | | | | | | If the driver is built as a module, autoload won't work because the module alias information is not filled. So user-space can't match the registered device with the corresponding module. Export the module alias information using the MODULE_DEVICE_TABLE() macro. Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* i2c: allow configuration of imx driver for ColdFire architectureGreg Ungerer2016-10-251-2/+2
| | | | | | | | | | | | The i2c controller used by Freescales iMX processors is the same hardware module used on Freescales ColdFire family of processors. We can use the existing i2c-imx driver on ColdFire family members. Modify the configuration to allow it to be selected when compiling for ColdFire targets. Signed-off-by: Greg Ungerer <gerg@linux-m68k.org> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* i2c: mark device nodes only in case of successful instantiationRalf Ramsauer2016-10-251-1/+10
| | | | | | | | | | | | | | | | | | | | | | Instantiated I2C device nodes are marked with OF_POPULATE. This was introduced in 4f001fd30145a6. On unloading, loaded device nodes will of course be unmarked. The problem are nodes that fail during initialisation: If a node fails, it won't be unloaded and hence not be unmarked. If a I2C driver module is unloaded and reloaded, it will skip nodes that failed before. Skip device nodes that are already populated and mark them only in case of success. Fixes: 4f001fd30145a6 ("i2c: Mark instantiated device nodes with OF_POPULATE") Signed-off-by: Ralf Ramsauer <ralf@ramses-pyramidenbau.de> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com> [wsa: use 14-digit commit sha] Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Cc: stable@kernel.org
* i2c: rk3x: Give the tuning value 0 during rk3x_i2c_v0_calc_timingsDavid Wu2016-10-251-0/+2
| | | | | | | | | | | | | | We found a bug that i2c transfer sometimes failed on 3066a board with stabel-4.8, the con register would be updated by uninitialized tuning value, it made the i2c transfer failed. So give the tuning value to be zero during rk3x_i2c_v0_calc_timings. Signed-off-by: David Wu <david.wu@rock-chips.com> Tested-by: Andy Yan <andy.yan@rock-chips.com> Reviewed-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Cc: stable@kernel.org
* i2c: hix5hd2: allow build with ARCH_HISIRuqiang Ju2016-10-251-4/+4
| | | | | | | | This driver should be buildable with ARCH_HISI, because some of other HiSilicon SoCs also use it. Signed-off-by: Ruqiang Ju <juruqiang@huawei.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* Merge tag 'tegra-for-4.8-i2c' of ↵Wolfram Sang2016-10-111-2/+8
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux into i2c/for-next [wsa: fell through the cracks, applied to 4.9 now] Signed-off-by: Wolfram Sang <wsa@the-dreams.de> i2c: 'i2c-bus' node support for v4.8-rc1 This includes the device tree binding and I2C core changes to support the i2c-bus subnode that I2C masters can use to describe their slaves in a separate namespace and therefore avoid clashing with potentially other subnodes.
| * i2c: core: Add support for 'i2c-bus' subnodeJon Hunter2016-06-301-2/+8
| | | | | | | | | | | | | | | | | | If the 'i2c-bus' device-tree node is present for an I2C adapter then parse this subnode for I2C slaves. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Acked-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Thierry Reding <treding@nvidia.com>
* | Merge branch 'i2c/for-4.9' of ↵Linus Torvalds2016-10-0768-1296/+1904
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux Pull i2c updates from Wolfram Sang: "Here is the 4.9 pull request from I2C including: - centralized error messages when registering to the core - improved lockdep annotations to prevent false positives - DT support for muxes, gates, and arbitrators - bus speeds can now be obtained from ACPI - i2c-octeon got refactored and now supports ThunderX SoCs, too - i2c-tegra and i2c-designware got a bigger bunch of updates - a couple of standard driver fixes and improvements" * 'i2c/for-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (71 commits) i2c: axxia: disable clks in case of failure in probe i2c: octeon: thunderx: Limit register access retries i2c: uniphier-f: fix misdetection of incomplete STOP condition gpio: pca953x: variable 'id' was used twice i2c: i801: Add support for Kaby Lake PCH-H gpio: pca953x: fix an incorrect lockdep warning i2c: add a warning to i2c_adapter_depth() lockdep: make MAX_LOCKDEP_SUBCLASSES unconditionally visible i2c: export i2c_adapter_depth() i2c: rk3x: Fix variable 'min_total_ns' unused warning i2c: rk3x: Fix sparse warning i2c / ACPI: Do not touch an I2C device if it belongs to another adapter i2c: octeon: Fix high-level controller status check i2c: octeon: Avoid sending STOP during recovery i2c: octeon: Fix set SCL recovery function i2c: rcar: add support for r8a7796 (R-Car M3-W) i2c: imx: make bus recovery through pinctrl optional i2c: meson: add gxbb compatible string i2c: uniphier-f: set the adapter to master mode when probing i2c: uniphier-f: avoid WARN_ON() of clk_disable() in failure path ...
| * | i2c: axxia: disable clks in case of failure in probeAlexey Khoroshilov2016-09-241-2/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | axxia_i2c_probe() does not disable clock in case of failure in i2c_add_adapter(). Also it ignores returned value from clk_prepare_enable(). Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * | i2c: octeon: thunderx: Limit register access retriesJan Glauber2016-09-242-12/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Do not infinitely retry register readq and writeq operations in order to not lock up the CPU in case the TWSI gets stuck. Return -ETIMEDOUT in case of a failed data read. For all other cases just return so subsequent operations will fail. Signed-off-by: Jan Glauber <jglauber@cavium.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * | i2c: uniphier-f: fix misdetection of incomplete STOP conditionMasahiro Yamada2016-09-241-5/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, the status register FI2C_SR is checked immediately after a STOP condition is issued in case of the deferred STOP condition. It takes typically 5-10 usec until the corresponding bits in the register are set, so the error check for "stop condition was not completed" is very likely to be false positive. Add wait code to relax the status register check. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * | i2c: i801: Add support for Kaby Lake PCH-HAndy Shevchenko2016-09-241-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Intel Kaby Lake PCH-H has the same legacy SMBus host controller than Intel Sunrisepoint PCH. It also has same iTCO watchdog on the bus. Add Kaby Lake PCH-H PCI ID to the list of supported devices. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * | i2c: add a warning to i2c_adapter_depth()Bartosz Golaszewski2016-09-241-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This routine is only used together with lockdep for nested locking. The number of lock subclasses is limited to 8 as defined in lockdep.h Emit a warning if the adapter depth exceeds the maximum number of lockdep subclasses. Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Acked-by: Peter Rosin <peda@axentia.se> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * | i2c: export i2c_adapter_depth()Bartosz Golaszewski2016-09-241-7/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For crazy setups in which an i2c gpio expander is behind an i2c gpio multiplexer controlled by a gpio provided a second expander using the same device driver we need to explicitly tell lockdep how to handle nested locking. Export i2c_adapter_depth() as public API to be reused outside of i2c core code. Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Acked-by: Peter Rosin <peda@axentia.se> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * | i2c: rk3x: Fix variable 'min_total_ns' unused warningDavid Wu2016-09-221-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixs the following warning: drivers/i2c/busses/i2c-rk3x.c: In function 'rk3x_i2c_v1_calc_timings': drivers/i2c/busses/i2c-rk3x.c:745:41: warning: variable 'min_total_ns' set but not used [-Wunused-but-set-variable] Reported-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: David Wu <david.wu@rock-chips.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * | i2c: rk3x: Fix sparse warningDavid Wu2016-09-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes the following sparse warning: drivers/i2c/busses/i2c-rk3x.c:888:17: warning: cast truncates bits from constant value (ffffffffff00 becomes ffffff00) Reported-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: David Wu <david.wu@rock-chips.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * | i2c / ACPI: Do not touch an I2C device if it belongs to another adapterMika Westerberg2016-09-221-7/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When enumerating I2C devices connected to an I2C adapter we scan the whole namespace (as it is possible to have devices anywhere in that namespace, not just below the I2C adapter device) and add each found device to the I2C bus in question. Now after commit 525e6fabeae2 ("i2c / ACPI: add support for ACPI reconfigure notifications") checking of the adapter handle to the one found in the I2cSerialBus() resource was moved to happen after resources of the I2C device has been parsed. This means that if the I2cSerialBus() resource points to an adapter that does not exists in the system we still parse those resources. This is problematic in particular because acpi_dev_resource_interrupt() tries to configure GSI if the device also has an Interrupt() resource. Failing to do that results errrors like this to be printed on the console: [ 10.409490] ERROR: Unable to locate IOAPIC for GSI 37 To fix this we pass the I2C adapter to i2c_acpi_get_info() and make sure the handle matches the one in the I2cSerialBus() resource before doing anything else to the device. Reported-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Nicolai Stange <nicstange@gmail.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * | i2c: octeon: Fix high-level controller status checkJan Glauber2016-09-211-9/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In case the high-level controller (HLC) is used the status code is reported at a different location. Check that location after HLC write operations if the ready bit is not set and return an appropriate error code instead of always returning -EAGAIN. Signed-off-by: Jan Glauber <jglauber@cavium.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * | i2c: octeon: Avoid sending STOP during recoveryDmitry Bazhenov2016-09-211-4/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Due to a bug in the ThunderX I2C hardware sending STOP during a recovery attempt could lock up the hardware. To work around this problem do not send STOP at the beginning of the recovery but use the override registers to bring the TWSI including the high-level controller out of the bad state. Signed-off-by: Dmitry Bazhenov <dmitry.bazhenov@auriga.com> Signed-off-by: Jan Glauber <jglauber@cavium.com> [Changed commit message] Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * | i2c: octeon: Fix set SCL recovery functionDmitry Bazhenov2016-09-211-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The set SCL recovery function unconditionally pulls the SCL line low. Only pull SCL line low according to val parameter. Signed-off-by: Dmitry Bazhenov <dmitry.bazhenov@auriga.com> Signed-off-by: Jan Glauber <jglauber@cavium.com> [Changed commit message] Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * | i2c: rcar: add support for r8a7796 (R-Car M3-W)Ulrich Hecht2016-09-161-0/+1
| | | | | | | | | | | | | | | | | | | | | Same as r8a7795. Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * | i2c: imx: make bus recovery through pinctrl optionalYang Li2016-09-151-9/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since commit 1c4b6c3bcf30 ("i2c: imx: implement bus recovery") the driver starts to use gpio/pinctrl to support optional bus recovery feature. But pinctrl is not always usable. There are platforms such as ls1021a and ls1043a that don't support pinctrl, and it could just be broken due to old/broken device tree. The patch makes it really optional that the probe function won't bailout on pinctrl problems instead it just disables bus recovery and prints out notification when there is problem with pinctrl. Since pinctrl is only used by bus recovery in this driver, move pinctrl initialization into bus recovery init function to prevent confusion. Signed-off-by: Li Yang <leoyang.li@nxp.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * | i2c: meson: add gxbb compatible stringNeil Armstrong2016-09-151-0/+1
| | | | | | | | | | | | | | | | | | | | | Signed-off-by: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: Jerome Brunet <jbrunet@baylibre.com> Acked-by: Kevin Hilman <khilman@baylibre.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * | i2c: uniphier-f: set the adapter to master mode when probingMasahiro Yamada2016-09-081-6/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, the adapter is set to the master mode at the first use. Since then, it is kept in the slave mode, so unexpected glitch signals on the I2C lines may cause the adapter into insane state. Setting it to the master mode along with initialization solves the problem. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reported-by: Akio Noda <noda.akio@socionext.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * | i2c: uniphier-f: avoid WARN_ON() of clk_disable() in failure pathMasahiro Yamada2016-09-081-41/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If clk_prepare_enable() fails, clk_disable_unprepare() is called in the failure path, where the enable_count is still zero, so it hits WARN_ON(core->enable_count == 0) in the clk_core_disable(). To fix this, make the clock setting more linear in the probe function so that it can exploit "goto err" in case of error. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * | i2c: uniphier: avoid WARN_ON() of clk_disable() in failure pathMasahiro Yamada2016-09-081-42/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If clk_prepare_enable() fails, clk_disable_unprepare() is called in the failure path, where the enable_count is still zero, so it hits WARN_ON(core->enable_count == 0) in the clk_core_disable(). To fix this, make the clock setting more linear in the probe function so that it can exploit "goto err" in case of error. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * | i2c: tegra: Fix assignment of boolean variablesJon Hunter2016-09-081-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix the following warnings reported by coccinelle for the Tegra I2C driver. drivers/i2c/busses/i2c-tegra.c:513:2-23: WARNING: Assignment of bool to 0/1 drivers/i2c/busses/i2c-tegra.c:539:3-24: WARNING: Assignment of bool to 0/1 Reported-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * | i2c: tegra: proper handling of error casesShardar Shariff Md2016-09-081-2/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To summarize the issue observed in error cases: SW Flow: For i2c message transfer, packet header and data payload is posted and then required error/packet completion interrupts are enabled later. HW flow: HW process the packet just after packet header is posted, if ARB lost/NACK error occurs (SW will not handle immediately when error happens as error interrupts are not enabled at this point). HW assumes error is acknowledged and clears current data in FIFO, But SW here posts the remaining data payload which still stays in FIFO as stale data (data without packet header). Now once the interrupts are enabled, SW handles ARB lost/NACK error by clearing the ARB lost/NACK interrupt. Now HW assumes that SW attended the error and will parse/process stale data (data without packet header) present in FIFO which causes invalid NACK errors. Fix: Enable the error interrupts before posting the packet into FIFO which make sure HW to not clear the fifo. Also disable the packet mode before acknowledging errors (ARB lost/NACK error) to not process any stale data. As error interrupts are enabled before posting the packet header use spinlock to avoid preempting. Signed-off-by: Shardar Shariff Md <smohammed@nvidia.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * | i2c: tegra: use atomic poll function during configurationShardar Shariff Md2016-09-081-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | Use readl_poll_timeout_atomic() function as *wait_for_config_load() function can be called from interrupt context. Signed-off-by: Shardar Shariff Md <smohammed@nvidia.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * | i2c: tegra: add separate function for config_load programingShardar Shariff Md2016-09-081-15/+26
| | | | | | | | | | | | | | | | | | | | | | | | Define separate function for configuration load register handling to make it use by different functions later. Signed-off-by: Shardar Shariff Md <smohammed@nvidia.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * | i2c: tegra: If fifo flush fails return errorShardar Shariff Md2016-09-081-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | During i2c controller initialization, when fifo flush fails return error instead of returning the error during exit. Signed-off-by: Shardar Shariff Md <smohammed@nvidia.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * | i2c: tegra: use readl_poll_timeout after config_load reg programmedShardar Shariff Md2016-09-081-9/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | After CONFIG_LOAD register is programmed instead of explicitly waiting for timeout, use readl_poll_timeout() to check for register value to get updated or wait till timeout. Signed-off-by: Shardar Shariff Md <smohammed@nvidia.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * | i2c: shmobile: Use ARCH_SHMOBILE instead of SUPERHGeert Uytterhoeven2016-09-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | "i2c-sh_mobile" is used on sh7343, sh7366, sh7722, sh7723, and sh7724 only. As all of the above select ARCH_SHMOBILE, restrict its driver dependencies from SUPERH to ARCH_SHMOBILE. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Simon Horman <horms+renesas@verge.net.au> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * | i2c: core: put literals on one line in dev_*() callsAndy Shevchenko2016-08-301-20/+23
| | | | | | | | | | | | | | | | | | | | | It's better to have strings in the code like they appeared in the output. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * | i2c: move locking operations to their own structPeter Rosin2016-08-302-14/+24
| | | | | | | | | | | | | | | | | | | | | | | | This makes it trivial to constify them, so do that. Signed-off-by: Peter Rosin <peda@axentia.se> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * | i2c: tegra: Add pinctrl supportJon Hunter2016-08-301-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On Tegra124/132 the pins for I2C6 are shared with the Display Port AUX (DPAUX) channel and on Tegra210 the pins for I2C4 and I2C6 are shared with DPAUX1 and DPAUX0, respectively. The multiplexing of the pins is handled by a register in the DPAUX and so the Tegra DPAUX driver has been updated to register a pinctrl device for managing these pins. The pins for these particular I2C devices are bound to the I2C device prior to probing. However, these I2C devices are in a different power partition to the DPAUX devices that own the pins. Hence, it is desirable to place the pins in the 'idle' state and allow the DPAUX power partition to switch off, when these I2C devices is not in use. Therefore, add calls to place the I2C pins in the 'default' and 'idle' states when the I2C device is runtime resumed and suspended, respectively. Please note that the pinctrl functions that set the state of the pins check to see if the devices has pins associated and will return zero if they do not. Therefore, it is safe to call these pinctrl functions even for I2C devices that do not have any pins associated. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Acked-by: Laxman Dewangan <ldewangan@nvidia.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * | i2c: tegra: Add runtime power-management supportJon Hunter2016-08-301-14/+46
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Update the Tegra I2C driver to use runtime PM and move the code in the tegra_i2c_clock_enable/disable() functions to the PM runtime resume and suspend callbacks, respectively. Note that given that CONFIG_PM is not mandatory for Tegra, if CONFIG_PM is not enabled and so runtime PM is not enabled, ensure that the I2C clocks are turned on during probe and kept on by calling the resume callback directly. In the function tegra_i2c_init(), the variable 'err' does not need to be initialised to zero in tegra_i2c_init() because it is initialised when pm_runtime_get_sync() is called. Furthermore, to ensure we only return 0 from tegra_i2c_init(), it is necessary to re-initialise 'err' to 0 after a successful call to pm_runtime_get_sync() because it can return a positive value on success. However, alternatively re-initialise 'err' by using the return value of the function tegra_i2c_flush_fifos() because it can only be 0 or -ETIMEDOUT. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Acked-by: Laxman Dewangan <ldewangan@nvidia.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * | i2c: tegra: Simplify I2C resumeJon Hunter2016-08-301-8/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The I2C adapter is unlocked regardless of whether the tegra_i2c_init() called during the resume is successful or not. However, if the tegra_i2c_init() is not successful, then ->is_suspended is not set to false. Simplify the resume code by only setting ->is_suspended to false if tegra_i2c_init() is successful and return the error code from tegra_i2c_init(). Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Acked-by: Laxman Dewangan <ldewangan@nvidia.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * | i2c: tegra: Use device name for adapter nameJon Hunter2016-08-301-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | All Tegra I2C devices have the name "Tegra I2C adapter" which is not very useful when viewing the I2C adapter names via the sysfs. Therefore, use the device name, which is unique for each I2C device, instead. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Acked-by: Laxman Dewangan <ldewangan@nvidia.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * | i2c: tegra: Remove non device-tree supportJon Hunter2016-08-301-9/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | Tegra has only supported device-tree for platform/board configuration for quite some time now and so simplify the Tegra I2C driver by dropping code for non device-tree platforms/boards. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * | i2c: tegra: Add missing new line charactersJon Hunter2016-08-301-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | Add missing new line characters for the various error messages. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Acked-by: Laxman Dewangan <ldewangan@nvidia.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * | i2c: tegra: Fix missing blank lines after declarationsJon Hunter2016-08-301-6/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Checkpatch warns about missing blank lines after declarations in the Tegra I2C driver and so fix these. Note that the initialisation of 'val' to zero in tegra_dvc_init() is unnecessary and so remove this. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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