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| * i2c: st: Implement bus clearPeter Griffin2016-05-13
| | | | | | | | | | | | | | | | | | | | | | | | >From I2C specifications: http://www.nxp.com/documents/user_manual/UM10204.pdf Chapter 3.1.16, when the i2c device held the SDA line low, the master should send 9 clocks pulses to try to recover. Signed-off-by: Frederic Pillon <frederic.pillon@st.com> Signed-off-by: Peter Griffin <peter.griffin@linaro.org> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: only check scl functions when using generic recoveryWolfram Sang2016-05-13
| | | | | | | | | | | | | | | | A custom recovery function doesn't need these pointers to be populated because it may work differently internally. Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Tested-by: Peter Griffin <peter.griffin@linaro.org>
| * i2c: algo-bit: declare i2c_bit_quirk_no_clk_stretch as staticMichele Curti2016-05-11
| | | | | | | | | | | | | | | | i2c_bit_quirk_no_clk_stretch is used in i2c-algo-bit.c only, so declare it as static. Signed-off-by: Michele Curti <michele.curti@gmail.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: tegra: disable clock before returning errorShardar Shariff Md2016-05-11
| | | | | | | | | | | | | | | | | | Disable clock before returning error in tegra_i2c_init() as its leaves i2c clock ON in case of error and never turns off again as it will have unbalanced clock enable/disable Signed-off-by: Shardar Shariff Md <smohammed@nvidia.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: mux: relax locking of the top i2c adapter during mux-locked muxingPeter Rosin2016-05-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With a i2c topology like the following GPIO ---| ------ BAT1 | v / I2C -----+----------+---- MUX | \ EEPROM ------ BAT2 there is a locking problem with the GPIO controller since it is a client on the same i2c bus that it muxes. Transfers to the mux clients (e.g. BAT1) will lock the whole i2c bus prior to attempting to switch the mux to the correct i2c segment. In the above case, the GPIO device is an I/O expander with an i2c interface, and since the GPIO subsystem knows nothing (and rightfully so) about the lockless needs of the i2c mux code, this results in a deadlock when the GPIO driver issues i2c transfers to modify the mux. So, observing that while it is needed to have the i2c bus locked during the actual MUX update in order to avoid random garbage on the slave side, it is not strictly a must to have it locked over the whole sequence of a full select-transfer-deselect mux client operation. The mux itself needs to be locked, so transfers to clients behind the mux are serialized, and the mux needs to be stable during all i2c traffic (otherwise individual mux slave segments might see garbage, or worse). Introduce this new locking concept as "mux-locked" muxes, and call the pre-existing mux locking scheme "parent-locked". Modify the i2c mux locking so that muxes that are "mux-locked" locks only the muxes on the parent adapter instead of the whole i2c bus when there is a transfer to the slave side of the mux. This lock serializes transfers to the slave side of the muxes on the parent adapter. Add code to i2c-mux-gpio and i2c-mux-pinctrl that checks if all involved gpio/pinctrl devices have a parent that is an i2c adapter in the same adapter tree that is muxed, and request a "mux-locked mux" if that is the case. Modify the select-transfer-deselect code for "mux-locked" muxes so that each of the select-transfer-deselect ops locks the mux parent adapter individually. Signed-off-by: Peter Rosin <peda@axentia.se> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: muxes always lock the parent adapterPeter Rosin2016-05-04
| | | | | | | | | | | | | | | | | | Instead of checking for i2c parent adapters for every lock/unlock, simply override the locking for muxes to always lock/unlock the parent adapter directly. Signed-off-by: Peter Rosin <peda@axentia.se> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: allow adapter drivers to override the adapter lockingPeter Rosin2016-05-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add i2c_lock_bus() and i2c_unlock_bus(), which call the new lock_bus and unlock_bus ops in the adapter. These funcs/ops take an additional flags argument that indicates for what purpose the adapter is locked. There are two flags, I2C_LOCK_ROOT_ADAPTER and I2C_LOCK_SEGMENT, but they are both implemented the same. For now. Locking the root adapter means that the whole bus is locked, locking the segment means that only the current bus segment is locked (i.e. i2c traffic on the parent side of a mux is still allowed even if the child side of the mux is locked). Also support a trylock_bus op (but no function to call it, as it is not expected to be needed outside of the i2c core). Implement i2c_lock_adapter/i2c_unlock_adapter in terms of the new locking scheme (i.e. lock with the I2C_LOCK_ROOT_ADAPTER flag). Locking the root adapter and locking the segment is the same thing for all root adapters (e.g. in the normal case of a simple topology with no i2c muxes). The two locking variants are also the same for traditional muxes (aka parent-locked muxes). These muxes traverse the tree, locking each level as they go until they reach the root. This patch is preparatory for a later patch in the series introducing mux-locked muxes, which behave differently depending on the requested locking. Since all current users are using i2c_lock_adapter, which is a wrapper for I2C_LOCK_ROOT_ADAPTER, we only need to annotate the calls that will not need to lock the root adapter for mux-locked muxes. I.e. the instances that needs to use I2C_LOCK_SEGMENT instead of i2c_lock_adapter/I2C_LOCK_ROOT_ADAPTER. Those instances are in the i2c_transfer and i2c_smbus_xfer functions, so that mux-locked muxes can single out normal i2c accesses to its slave side and adjust the locking for those accesses. Signed-off-by: Peter Rosin <peda@axentia.se> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: uniphier: add "\n" at the end of error logMasahiro Yamada2016-04-27
| | | | | | | | | | | | | | Just in case. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: mv64xxx: remove CONFIG_HAVE_CLK conditionalsThomas Petazzoni2016-04-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When clock support was added to the i2c-mv64xxx, not all clk functions had stubs when for !CONFIG_HAVE_CLK configurations. However, nowadays, both "struct clk" and all the clock framework functions have stubs when CONFIG_HAVE_CLK is not enabled, so it no longer makes sense to carry such compile-time conditionals in the driver. This commit was compile tested on both ARM64 (which has both CONFIG_OF=y and CONFIG_HAVE_CLK=y) and PowerPC c2k_defconfig (which has CONFIG_OF=y, CONFIG_HAVE_CLK disabled, and the i2c-mv64xxx driver enabled). The only non-trivial change is in the mv64xxx_of_config() function, which was returning -ENODEV unconditionally if CONFIG_HAVE_CLK was disabled. Simply removing this condition works fine because the first test done by the function is to verify if drv_data->clk points to a valid clock, and if it doesn't, we return -ENODEV. When CONFIG_HAVE_CLK is disabled, devm_clk_get() unconditionally returns NULL, so mv64xxx_of_config() will return -ENODEV when no clock is provided, which is the intended behavior. Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: mv64xxx: use clk_{prepare_enable,disable_unprepare}Thomas Petazzoni2016-04-27
| | | | | | | | | | | | | | | | | | | | | | Instead of separately calling clk_prepare()/clk_enable(), use clk_prepare_enable(), and instead of calling clk_disable()/clk_unprepare(), use clk_disable_unprepare(). Those handy shortcuts have been introduced specifically to simplify the numerous call sites were both functions were called in sequence. Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: mv64xxx: handle probe deferral for the clockThomas Petazzoni2016-04-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a clock is registered by a platform driver and not by the OF_CLK_DECLARE() mechanism, it might show up after the first attempt to probe i2c-mv64xxx. In order to solve this, we need to handle -EPROBE_PREFER as a special return value of devm_clk_get(), and return the same error code from probe(). This gives us three situations: - There is no reference to a clock in the DT. In this case, devm_clk_get() returns an error that is not -EPROBE_DEFER (something like -ENODEV), and we continue the probing without enabling the clock. - There is a reference to the clock in the DT, and the clock is ready. devm_clk_get() returns a valid reference to the clock, and we prepare/enable it. - There is a reference to the clock in the DT, but the clock is not ready. devm_clk_get() returns -EPROBE_DEFER, and we exit from probe() with the same error code so that probe() is tried again later. This is needed for Marvell Armada 7K/8K, where the clock driver is a platform driver. Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: mv64xxx: enable the driver on ARCH_MVEBUThomas Petazzoni2016-04-27
| | | | | | | | | | | | | | | | | | The new ARM64 Marvell Armada 7K/8K SoC family is using the same I2C controller as the 32-bits Marvell EBU SoCs, so this commit allows mv64xxx to be enabled when ARCH_MVEBU=y. Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: octeon: Add workaround for broken irqs on CN3860David Daney2016-04-27
| | | | | | | | | | | | | | | | | | | | CN3860 does not interrupt the CPU when the i2c status changes. If we get a timeout, and see the status has in fact changed, we know we have this problem, and drop back to polling. Signed-off-by: David Daney <ddaney@caviumnetworks.com> Signed-off-by: Jan Glauber <jglauber@cavium.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: nforce2: Use IS_ENABLED() instead of checking for built-in or moduleJavier Martinez Canillas2016-04-26
| | | | | | | | | | | | | | | | The IS_ENABLED() macro checks if a Kconfig symbol has been enabled either built-in or as a module, use that macro instead of open coding the same. Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: imx: reduce load by using usleep_range instead of udelayOleksij Rempel2016-04-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Documentation/timers/timers-howto.txt recommends to use usleep_range on delays > 10usec. According to my test results with Neonode zForce touchscreen driver, usleep_range indeed reduces CPU load. Stats collected with "./perf record -a -g -F 1000 sleep 10" i2c-imx with udelay(50): 34.19% 0.00% irq/220-Neonode [kernel.kallsyms] [k] irq_thread ---irq_thread |--33.75%--irq_thread_fn | |--19.27%--0x7f08a878 | | i2c_master_recv | | i2c_transfer | | __i2c_transfer | | i2c_imx_xfer | | |--11.71%--i2c_imx_trx_complete | | |--5.70%--i2c_imx_start <<<<---------------- | | | |--5.38%--__timer_const_udelay | | | | __timer_delay | | | | --5.07%--read_current_timer i2c-imx with usleep_range(50,100) 29.08% 0.00% irq/220-Neonode [kernel.kallsyms] [k] irq_thread ---irq_thread |--28.89%--irq_thread_fn | |--17.21%--0x7f08a878 | | i2c_master_recv | | |--17.14%--i2c_transfer | | | __i2c_transfer | | | i2c_imx_xfer | | | |--14.29%--i2c_imx_trx_complete | | | |--1.42%--i2c_imx_start <<<<---------- | | | | |--0.71%--usleep_range | | | | |--0.53%--i2c_imx_bus_busy Signed-off-by: Oleksij Rempel <linux@rempel-privat.de> Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com> Reviewed-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: octeon: Improve performance if interrupt is earlyPeter Swain2016-04-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is a race between the TWSI interrupt and the condition that is required before proceeding: Low-level: interrupt flag bit must be set High-level controller: valid bit must be clear If the interrupt comes too early and the condition is not met the wait will time out, and the transfer is aborted leading to very poor performance. To avoid this race retry for the condition ~80 µs later. The retry is avoided on the very first invocation of wait_event_timeout() (which tests the condition before entering the wait and is therefore always wrong in this case). EEPROM reads on 100kHz i2c now measure ~5.2kB/s, about 1/2 what's achievable, and much better than the worst-case 100 bytes/sec before. While at it remove the debug print from the low-level wait function. Signed-off-by: Peter Swain <pswain@cavium.com> Signed-off-by: Jan Glauber <jglauber@cavium.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: octeon: Remove zero-length message supportJan Glauber2016-04-26
| | | | | | | | | | | | | | | | | | | | | | | | Zero-length message support (SMBUS QUICK or i2c) never worked with the Octeon hardware. Disable SMBUS QUICK support and bail out in case of a zero-length i2c request. After this change 'i2c-detect -q' will return an error on Octeon but the previously reported results were wrong anyway. Signed-off-by: Jan Glauber <jglauber@cavium.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: s3c2410: Check clk_prepare_enable() return valueJavier Martinez Canillas2016-04-25
| | | | | | | | | | | | | | | | | | The clk_prepare_enable() function can fail so check the return value and propagate the error in case of a failure. Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com> Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: s3c2410: Print errno code in error logsJavier Martinez Canillas2016-04-25
| | | | | | | | | | | | | | | | | | The driver not always prints the error code in case of a failure but this information can be very useful for debugging. So let's print if available. Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com> Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: s3c2410: Cleanup indentation and comment styleKrzysztof Kozlowski2016-04-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Improve the readability by: - fixing indentation, - switching to proper block comments, - removing spurious blank lines, - checkpatch: void function return statements are not generally useful, - checkpatch: braces {} are not necessary for any arm of this statement, - checkpatch: missing a blank line after declarations. Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: s3c2410: Minor function-level comment cleanupKrzysztof Kozlowski2016-04-25
| | | | | | | | | | | | | | | | | | Cleanup the weird function-level comments and remove obvious documentation for probe/remove. Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: s3c2410: Add missing clock unprepare on probe() error pathKrzysztof Kozlowski2016-04-25
| | | | | | | | | | | | | | | | | | If during probe() the s3c24xx_i2c_init() failed, the clock was left in disabled but prepared state. Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: octeon: Add support for cn78xx chipsJan Glauber2016-04-25
| | | | | | | | | | | | | | | | | | cn78xx has a different interrupt architecture, so we have to manage the interrupts differently. Signed-off-by: David Daney <ddaney@caviumnetworks.com> Signed-off-by: Jan Glauber <jglauber@cavium.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: octeon: Enable High-Level ControllerDavid Daney2016-04-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use High-Level Controller (HLC) when possible. The HLC can read/write up to 8 bytes and is completely optional. The most important difference of the HLC is that it only requires one interrupt for a transfer (up to 8 bytes) where the low-level read/write requires 2 interrupts plus one interrupt per transferred byte. Since the interrupts are costly using the HLC improves the performance. Also, the HLC provides improved error handling. Signed-off-by: David Daney <ddaney@caviumnetworks.com> Signed-off-by: Jan Glauber <jglauber@cavium.com> [wsa: fixed trivial checkpatch warnings] Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: octeon: Add flush writeq helper functionPeter Swain2016-04-25
| | | | | | | | | | | | | | | | | | Add helper function that reads back a value after writing to make sure the write is finished and use it in octeon_i2c_write_int(). Signed-off-by: Peter Swain <pswain@cavium.com> Signed-off-by: Jan Glauber <jglauber@cavium.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: octeon: Use i2c recovery frameworkJan Glauber2016-04-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Switch to the i2c bus recovery framework using generic SCL recovery. If this fails try to reset the hardware. The recovery is triggered during START on timeout of the interrupt or failure to reach the START / repeated-START condition. The START function is moved to xfer and while at it remove the xfer debug message (i2c core already provides a debug message for this). Signed-off-by: Jan Glauber <jglauber@cavium.com> [wsa: removed one empty line] Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: octeon: Improve error status checkingJan Glauber2016-04-25
| | | | | | | | | | | | | | | | | | | | | | | | | | Introduce a function that checks for valid status codes depending on the phase of a transmit or receive. Also add all existing status codes and improve error handling for various states. The Octeon TWSI has an "assert acknowledge" bit (TWSI_CTL_AAK) that is required to be set in master receive mode until the last byte is requested. The state check needs to consider if this bit was set. Signed-off-by: Jan Glauber <jglauber@cavium.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: s3c2410: Use SET_NOIRQ_SYSTEM_SLEEP_PM_OPS instead of open-codedAxel Lin2016-04-24
| | | | | | | | | | | | | | | | Use SET_NOIRQ_SYSTEM_SLEEP_PM_OPS to simplify the code. Signed-off-by: Axel Lin <axel.lin@ingics.com> Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: exynos5: Use SET_NOIRQ_SYSTEM_SLEEP_PM_OPS instead of open-codedAxel Lin2016-04-24
| | | | | | | | | | | | | | | | Use SET_NOIRQ_SYSTEM_SLEEP_PM_OPS to simplify the code. Signed-off-by: Axel Lin <axel.lin@ingics.com> Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: mux: pinctrl: fix indentation for better readabilityWolfram Sang2016-04-24
| | | | | | | | | | | | | | | | | | | | smatch rightfully says: drivers/i2c/muxes/i2c-mux-pinctrl.c:175 i2c_mux_pinctrl_probe() warn: inconsistent indenting Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Acked-by: Peter Rosin <peda@axentia.se> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: omap: drop the lock hard irq contextSebastian Andrzej Siewior2016-04-24
| | | | | | | | | | | | | | | | | | | | | | | | | | The lock is taken while reading two registers. On RT the first lock is taken in hard irq where it might sleep and in the threaded irq. The threaded irq runs in oneshot mode so the hard irq does not run until the thread the completes so there is no reason to grab the lock. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> [grygorii.strashko@ti.com: drop locking from isr completely and remove lock field from struct omap_i2c_dev] Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: dln2: Pass forward ACPI companionIrina Tirdea2016-04-24
| | | | | | | | | | | | | | | | | | | | Share the ACPI companion for the platform device with the i2c adapter, so that the adapter has access to the properties defined in ACPI tables. Signed-off-by: Irina Tirdea <irina.tirdea@intel.com> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: mux: drop old unused i2c-mux apiPeter Rosin2016-04-22
| | | | | | | | | | | | | | | | All i2c mux users are using an explicit i2c mux core, drop support for implicit i2c mux cores. Signed-off-by: Peter Rosin <peda@axentia.se> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: i2c-mux-reg: convert to use an explicit i2c mux corePeter Rosin2016-04-22
| | | | | | | | | | | | | | | | | | Allocate an explicit i2c mux core to handle parent and child adapters etc. Update the select/deselect ops to be in terms of the i2c mux core instead of the child adapter. Signed-off-by: Peter Rosin <peda@axentia.se> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: i2c-mux-pca954x: convert to use an explicit i2c mux corePeter Rosin2016-04-22
| | | | | | | | | | | | | | | | | | | | | | | | | | Allocate an explicit i2c mux core to handle parent and child adapters etc. Update the select/deselect ops to be in terms of the i2c mux core instead of the child adapter. Add a mask to handle the case where not all child adapters should cause a mux deselect to happen, now that there is a common deselect op for all child adapters. Signed-off-by: Peter Rosin <peda@axentia.se> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: i2c-mux-pca9541: convert to use an explicit i2c mux corePeter Rosin2016-04-22
| | | | | | | | | | | | | | | | | | Allocate an explicit i2c mux core to handle parent and child adapters etc. Update the select/deselect ops to be in terms of the i2c mux core instead of the child adapter. Signed-off-by: Peter Rosin <peda@axentia.se> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: i2c-arb-gpio-challenge: convert to use an explicit i2c mux corePeter Rosin2016-04-22
| | | | | | | | | | | | | | | | | | Allocate an explicit i2c mux core to handle parent and child adapters etc. Update the select/deselect ops to be in terms of the i2c mux core instead of the child adapter. Signed-off-by: Peter Rosin <peda@axentia.se> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: i2c-mux-pinctrl: convert to use an explicit i2c mux corePeter Rosin2016-04-22
| | | | | | | | | | | | | | | | | | Allocate an explicit i2c mux core to handle parent and child adapters etc. Update the select/deselect ops to be in terms of the i2c mux core instead of the child adapter. Signed-off-by: Peter Rosin <peda@axentia.se> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: i2c-mux-gpio: convert to use an explicit i2c mux corePeter Rosin2016-04-22
| | | | | | | | | | | | | | | | | | Allocate an explicit i2c mux core to handle parent and child adapters etc. Update the select/deselect ops to be in terms of the i2c mux core instead of the child adapter. Signed-off-by: Peter Rosin <peda@axentia.se> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: mux: add common data for every i2c-mux instancePeter Rosin2016-04-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | All i2c-muxes have a parent adapter and one or many child adapters. A mux also has some means of selection. Previously, this was stored per child adapter, but it is only needed to keep track of this per mux. Add an i2c mux core, that keeps track of this consistently. Also add some glue for users of the old interface, which will create one implicit mux core per child adapter. Signed-off-by: Peter Rosin <peda@axentia.se> Tested-by: Antti Palosaari <crope@iki.fi> Tested-by: Crestez Dan Leonard <leonard.crestez@intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: rk3x: switch to i2c generic dt parsingDavid Wu2016-04-14
| | | | | | | | | | | | | | Switch to the new generic functions: i2c_parse_fw_timings(). Signed-off-by: David Wu <david.wu@rock-chips.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: octeon: Remove superfluous check in octeon_i2c_test_iflgJan Glauber2016-04-14
| | | | | | | | | | | | | | Remove superfluous check and stray newline. Signed-off-by: Jan Glauber <jglauber@cavium.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: octeon: Introduce helper functions for register accessJan Glauber2016-04-14
| | | | | | | | | | | | | | | | | | Add helper functions for control, data and status register access. This simplifies the code and makes the purpose of the register access clearer. Signed-off-by: Jan Glauber <jglauber@cavium.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: octeon: Rename [read|write]_sw to reg_[read|write]Jan Glauber2016-04-14
| | | | | | | | | | | | | | | | Rename the [read|write]_sw functions to make it clearer they access the TWSI registers. Signed-off-by: Jan Glauber <jglauber@cavium.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: octeon: Move set-clock and init-lowlevel upwardJan Glauber2016-04-13
| | | | | | | | | | | | | | | | No functional change, just moving the functions upward in preparation of improving the recovery. Signed-off-by: Jan Glauber <jglauber@cavium.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: octeon: Increase retry default and use fixed timeout valueJan Glauber2016-04-13
| | | | | | | | | | | | | | | | | | | | Convert the adapter timeout to 2 ms independently of depending on CONFIG_HZ. CONFIG_HZ is 100 for MIPS Cavium-Octeon so the timeout value is not changed. Also set retries to 5 to improve robustness. Signed-off-by: Jan Glauber <jglauber@cavium.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: tegra: enable multi master mode for tegra210Shardar Shariff Md2016-04-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Enable multi-master mode in I2C_CNFG reg based on hw features. Using single/multi-master mode bit introduced for Tegra210, whereas multi-master mode is enabled by default in HW for T124 and earlier Tegra SOC. Enabling this bit doesn't explicitly start treating the bus has having multiple masters, but will start checking for arbitration lost and reporting when it occurs. The Tegra210 I2C controller supports single/multi master mode. Add chipdata for Tegra210 and its compatibility string so that Tegra210 will select data that enables multi master mode correctly. Do below prerequisites for multi-master bus if "multi-master" dt property entry is added. 1. Enable 1st level clock always set. 2. Disable 2nd level clock gating (slcg which is supported from T124 SOC and later chips) Signed-off-by: Shardar Shariff Md <smohammed@nvidia.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: i801: Add runtime PM support with autosuspendJarkko Nikula2016-04-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allow runtime PM so that PM and PCI core can put the device into low-power state when idle and resume it back when needed in those platforms that support PM for i801 device. Enable also autosuspend with 1 second delay in order to not needlessly toggle power state on and off if there are multiple transactions during short time. Device is resumed at the beginning of bus access and marked idle ready for autosuspend at the end of it. Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Tested-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: i801: Convert to struct dev_pm_ops for suspend/resumeJarkko Nikula2016-04-12
| | | | | | | | | | | | | | | | | | | | | | | | Stop using legacy PCI PM support and convert to standard dev_pm_ops. This provides more straightforward path to add runtime PM. While at it remove explicit PCI power state control and configuration space save/restore as the PCI core does it. Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Tested-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: let I2C masters ignore their children for PMLinus Walleij2016-04-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When using a certain I2C device with runtime PM enabled on a certain I2C bus adaper the following happens: struct amba_device *foo \ struct i2c_adapter *bar \ struct i2c_client *baz The AMBA device foo has its device PM struct set to ignore children with pm_suspend_ignore_children(&foo->dev, true). This makes runtime PM work just fine locally in the driver: the fact that devices on the bus are suspended or resumed individually does not affect its operation, and the hardware does not power up unless transferring messages. However this child ignorance property is not inherited into the struct i2c_adapter *bar. On system suspend things will work fine. On system resume the following annoying phenomenon occurs: - In the pm_runtime_force_resume() path of struct i2c_client *baz, pm_runtime_set_active(&baz->dev); is eventually called. - This becomes __pm_runtime_set_status(&baz->dev, RPM_ACTIVE); - __pm_runtime_set_status() detects that RPM state is changed, and checks whether the parent is: not active (RPM_ACTIVE) and not ignoring its children If this happens it concludes something is wrong, because a parent that is not ignoring its children must be active before any children activate. - Since the struct i2c_adapter *bar does not ignore its children, the PM core thinks that it must indeed go online before its children, the check bails out with -EBUSY, i.e. the i2c_client *baz thinks it can't work because it's parent is not online, and it respects its parent. - In the driver the .resume() callback returns -EBUSY from the runtime_force_resume() call as per above. This leaves the device in a suspended state, leading to bad behaviour later when the device is used. The following debug print is made with an extra printg patch but illustrates the problem: [ 17.040832] bh1780 2-0029: parent (i2c-2) is not active parent->power.ignore_children = 0 [ 17.040832] bh1780 2-0029: pm_runtime_force_resume: pm_runtime_set_active() failed (-16) [ 17.040863] dpm_run_callback(): pm_runtime_force_resume+0x0/0x88 returns -16 [ 17.040863] PM: Device 2-0029 failed to resume: error -16 Fix this by letting all struct i2c_adapter:s ignore their children: i2c children have no business doing keeping their parents awake: they are completely autonomous devices that just use their parent to talk, a usecase which must be power managed in the host on a per-message basis. Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
generated by cgit v1.2.2 (git 2.25.0) at 2025-08-05 05:02:19 -0400