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| | * | i2c: pmcmsp: make use of the new infrastructure for quirksWolfram Sang2015-03-13
| | | | | | | | | | | | | | | | Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| | * | i2c: viperboard: make use of the new infrastructure for quirksWolfram Sang2015-03-13
| | | | | | | | | | | | | | | | Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| | * | i2c: powermac: make use of the new infrastructure for quirksWolfram Sang2015-03-13
| | | | | | | | | | | | | | | | Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| | * | i2c: dln2: make use of the new infrastructure for quirksWolfram Sang2015-03-13
| | | | | | | | | | | | | | | | Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| | * | i2c: axxia: make use of the new infrastructure for quirksWolfram Sang2015-03-13
| | | | | | | | | | | | | | | | Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| | * | i2c: cpm: make use of the new infrastructure for quirksWolfram Sang2015-03-13
| | | | | | | | | | | | | | | | Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| | * | i2c: qup: make use of the new infrastructure for quirksWolfram Sang2015-03-13
| | | | | | | | | | | | | | | | | | | | Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Tested-by: Ivan T. Ivanov <iivanov@mm-sol.com>
| | * | i2c: opal: make use of the new infrastructure for quirksWolfram Sang2015-03-13
| | | | | | | | | | | | | | | | | | | | Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Tested-by: Neelesh Gupta <neelegup@linux.vnet.ibm.com>
| | * | i2c: at91: make use of the new infrastructure for quirksWolfram Sang2015-03-13
| | | | | | | | | | | | | | | | | | | | Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Tested-By: Ludovic Desroches <ludovic.desroches@atmel.com>
| | * | i2c: add quirk checks to coreWolfram Sang2015-03-13
| | |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Let the core do the checks if HW quirks prevent a transfer. Saves code from drivers and adds consistency. Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Tested-by: Ray Jui <rjui@broadcom.com> Tested-by: Ivan T. Ivanov <iivanov@mm-sol.com> Tested-by: Neelesh Gupta <neelegup@linux.vnet.ibm.com> Tested-By: Ludovic Desroches <ludovic.desroches@atmel.com>
| * | i2c: pca954x: improve usage of gpiod APIUwe Kleine-König2015-03-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since 39b2bbe3d715 (gpio: add flags argument to gpiod_get*() functions) which appeared in v3.17-rc1, the gpiod_get* functions take an additional parameter that allows to specify direction and initial value for outputs. Also there is an *_optional variant that serves well here. The sematics is slightly changed here by using it. Now if a reset gpio is specified and getting hold on it fails, pca954x_probe fails, too. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * | i2c: i801: Use managed pcim_* PCI device initialization and reservationJarkko Nikula2015-03-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Simplifies the code a bit and makes easier to disable PCI device on driver detach by removing the pcim_pin_device() call in the future if needed. Reason why i2c-i801.c doesn't ever call pci_disable_device() was because it made some systems to hang during power-off. See commit d6fcb3b9cf77 ("[PATCH] i2c-i801.c: don't pci_disable_device() after it was just enabled") and http://marc.info/?l=linux-kernel&m=115160053309535&w=2 Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Reviewed-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * | i2c: i801: Remove pci_enable_device() call from i801_resume()Jarkko Nikula2015-03-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since pci_disable_device() is not called from i801_suspend() and power state is set already it means that subsequent pci_enable_device() calls do practically nothing but monotonically increase struct pci_dev enable_cnt. Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Reviewed-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * | i2c: i801: Use managed devm_* memory and irq allocationJarkko Nikula2015-03-09
| | | | | | | | | | | | | | | | | | | | | | | | This simplifies the error and remove paths. Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Reviewed-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * | i2c: i801: Remove i801_driver forward declarationJarkko Nikula2015-03-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | struct pci_driver i801_driver forward declaration is needed only for accessing the name field. Remove it and use dev_driver_string() instead. Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Reviewed-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * | i2c: i801: Don't break user-visible stringsJarkko Nikula2015-03-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | It makes more difficult to grep these error prints from sources if they are split to multiple source lines. Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Reviewed-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* | | Revert "i2c: core: Dispose OF IRQ mapping at client removal time"Jakub Kicinski2015-03-12
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit e4df3a0b6228 ("i2c: core: Dispose OF IRQ mapping at client removal time") Calling irq_dispose_mapping() will destroy the mapping and disassociate the IRQ from the IRQ chip to which it belongs. Keeping it is OK, because existent mappings are reused properly. Also, this commit breaks drivers using devm* for IRQ management on OF-based systems because devm* cleanup happens in device code, after bus's remove() method returns. Signed-off-by: Jakub Kicinski <kubakici@wp.pl> Reported-by: Sébastien Szymanski <sebastien.szymanski@armadeus.com> Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> [wsa: updated the commit message with findings fromt the other bug report] Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Cc: stable@kernel.org Fixes: e4df3a0b6228
* | i2c: designware-baytrail: baytrail_i2c_acquire() might sleepAndy Shevchenko2015-03-06
| | | | | | | | | | | | | | | | | | | | This patch marks baytrail_i2c_acquire() that it might sleep. Also it chages while-loop to do-while and, though it is matter of taste, gives a chance to check one more time before report a timeout. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: David E. Box <david.e.box@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* | i2c: designware-baytrail: cross-check lock functionsAndy Shevchenko2015-03-06
| | | | | | | | | | | | | | | | | | It seems the idea behind the cross-check is to prevent acquire semaphore when there is no release callback and vice versa. Thus, patch fixes a typo. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: David E. Box <david.e.box@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* | i2c: designware-baytrail: fix sparse warningsAndy Shevchenko2015-03-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is no need to export functions that are used as the callbacks in the struct dw_i2c_dev. Otherwise we get the following warnings: drivers/i2c/busses/i2c-designware-baytrail.c:63:5: warning: symbol 'baytrail_i2c_acquire' was not declared. Should it be static? drivers/i2c/busses/i2c-designware-baytrail.c:114:6: warning: symbol 'baytrail_i2c_release' was not declared. Should it be static? While here, do few indentation fixes, remove i2c_dw_eval_lock_support() from functions exported to the modules and redundant assignment of local sem variable. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: David E. Box <david.e.box@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* | i2c: designware-baytrail: fix typo in error pathAndy Shevchenko2015-03-06
| | | | | | | | | | | | | | | | | | It seems we have same message for different return values in get_sem() and baytrail_i2c_acquire(). I suspect this is just a typo, so this patch fixes it. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: David E. Box <david.e.box@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* | i2c: designware-baytrail: describe magic numbersAndy Shevchenko2015-03-06
|/ | | | | | | | | | The patch converts hardcoded numerical constants to a named ones. While here, align the variable name in get_sem() and reset_semaphore(). Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: David E. Box <david.e.box@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* Merge branch 'i2c/for-3.20' of ↵Linus Torvalds2015-02-21
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux Pull i2c updates from Wolfram Sang: "Summary: - legacy PM code removed from the core, there were no users anymore (thanks to Lars-Peter Clausen) - new driver for Broadcom iProc - bigger driver updates for designware, rk3x, cadence, ocores - a bunch of smaller updates and bugfixes" * 'i2c/for-3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (31 commits) i2c: ocores: rework clk code to handle NULL cookie i2c: designware-baytrail: another fixup for proper Kconfig dependencies i2c: fix reference to functionality constants definition i2c: iproc: Add Broadcom iProc I2C Driver i2c: designware-pci: update Intel copyright line i2c: ocores: add common clock support i2c: hix5hd2: add COMPILE_TEST i2c: clarify comments about the dev_released completion i2c: ocores: fix clock-frequency binding usage i2c: tegra: Maintain CPU endianness i2c: designware-baytrail: use proper Kconfig dependencies i2c: designware: Do not calculate SCL timing parameters needlessly i2c: do not try to load modules for of-registered devices i2c: designware: Add Intel Baytrail PMIC I2C bus support i2c: designware: Add i2c bus locking support of: i2c: Add i2c-mux-idle-disconnect DT property to PCA954x mux driver i2c: designware: use {readl|writel}_relaxed instead of readl/writel i2c: designware-pci: no need to provide clk_khz i2c: designware-pci: remove Moorestown support i2c: imx: whitespace and checkpatch cleanup ...
| * i2c: ocores: rework clk code to handle NULL cookieWolfram Sang2015-02-20
| | | | | | | | | | | | | | | | | | | | | | For, !HAVE_CLK the clk API returns a NULL cookie. Rework the initialization code to handle that. If clk_get_rate() delivers 0, we use the fallback mechanisms. The patch is pretty easy when ignoring white space issues (git diff -b). Suggested-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Tested-by: Max Filippov <jcmvbkbc@gmail.com>
| * i2c: designware-baytrail: another fixup for proper Kconfig dependenciesWolfram Sang2015-02-19
| | | | | | | | | | | | | | | | IOSF_MBI is tristate. Baytrail driver isn't. Reported-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: David E. Box <david.e.box@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: iproc: Add Broadcom iProc I2C DriverRay Jui2015-02-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Add initial support to the Broadcom iProc I2C controller found in the iProc family of SoCs. The iProc I2C controller has separate internal TX and RX FIFOs, each has a size of 64 bytes. The iProc I2C controller supports two bus speeds including standard mode (100kHz) and fast mode (400kHz) Signed-off-by: Ray Jui <rjui@broadcom.com> Reviewed-by: Scott Branden <sbranden@broadcom.com> Reviewed-by: Kevin Cernekee <cernekee@chromium.org> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: designware-pci: update Intel copyright lineAndy Shevchenko2015-02-17
| | | | | | | | | | | | | | | | While here, fix few indentations issues across the code. There is no functional change. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: ocores: add common clock supportMax Filippov2015-02-05
| | | | | | | | | | | | | | | | Allow bus clock specification as a common clock handle. This makes this controller easier to use in a setup based on common clock framework. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: hix5hd2: add COMPILE_TESTZhangfei Gao2015-02-05
| | | | | | | | | | | | | | | | | | | | Commit 9439eb3ab9d1ec ("asm-generic: io: implement relaxed accessor macros as conditional wrappers") has added {read,write}{b,w,l,q}_relaxed to include/asm-generic/io.h. So COMPILE_TEST can be added. Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: clarify comments about the dev_released completionWolfram Sang2015-02-05
| | | | | | | | | | | | | | | | There was quite some confusion why this completion is there and if it is still necessary. Sadly, it is. However, let's improve the comments and share what we rediscovered. Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: ocores: fix clock-frequency binding usageMax Filippov2015-02-05
| | | | | | | | | | | | | | | | | | | | | | | | | | clock-frequency property is meant to control the bus frequency for i2c bus drivers, but it was incorrectly used to specify i2c controller input clock frequency. Introduce new attribute, opencores,ip-clock-frequency, that specifies i2c controller clock frequency and make clock-frequency attribute compatible with other i2c drivers. Maintain backwards compatibility in case opencores,ip-clock-frequency attribute is missing. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: tegra: Maintain CPU endiannessDmitry Osipenko2015-01-26
| | | | | | | | | | | | | | | | Support CPU BE mode by adding endianness conversion for memcpy interactions. Signed-off-by: Dmitry Osipenko <digetx@gmail.com> Acked-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: designware-baytrail: use proper Kconfig dependenciesWolfram Sang2015-01-26
| | | | | | | | | | | | | | | | | | | | IOSF_MBI depends on PCI, so we should not select it but depend on it. This ensures also we compile on X86 only, other archs will break because of an arch specific include. Also depend on ACPI since this driver uses it. Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Acked-by: David E. Box <david.e.box@linux.intel.com>
| * i2c: designware: Do not calculate SCL timing parameters needlesslyJarkko Nikula2015-01-26
| | | | | | | | | | | | | | | | | | Do SCL timing parameter calculation conditionally depending are custom parameters provided since calculated values will get instantly overwritten by provided parameters. Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: do not try to load modules for of-registered devicesDmitry Torokhov2015-01-26
| | | | | | | | | | | | | | | | | | | | | | | | | | Trying to register an I2C device asynchronously (via async_schedule() call) results in an ugly warning from request_module() warning about potential deadlock (because request_module tries to wait for async works to complete). While we could try to switch to request_module_nowait(), other buses, as well as I2C itself when not using device tree, do not try to load modules, but rather rely on the standard infrastructure (udev) to execute module loading, and we should be doing the same. Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: designware: Add Intel Baytrail PMIC I2C bus supportDavid Box2015-01-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch implements an I2C bus sharing mechanism between the host and platform hardware on select Intel BayTrail SoC platforms using the X-Powers AXP288 PMIC. On these platforms access to the PMIC must be shared with platform hardware. The hardware unit assumes full control of the I2C bus and the host must request access through a special semaphore. Hardware control of the bus also makes it necessary to disable runtime pm to avoid interfering with hardware transactions. Signed-off-by: David E. Box <david.e.box@linux.intel.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: designware: Add i2c bus locking supportDavid Box2015-01-26
| | | | | | | | | | | | | | | | | | | | Adds support for acquiring and releasing a hardware bus lock in the i2c designware core transfer function. This is needed for i2c bus controllers that are shared with but not controlled by the kernel. Signed-off-by: David E. Box <david.e.box@linux.intel.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * of: i2c: Add i2c-mux-idle-disconnect DT property to PCA954x mux driverAlexander Sverdlin2015-01-23
| | | | | | | | | | | | | | | | | | | | | | Add i2c-mux-idle-disconnect device tree property to PCA954x mux driver. The new property forces the multiplexer to disconnect child buses in idle state. This is used, for example, when there are several multiplexers on the same bus and the devices on the underlying buses might have same I2C addresses. Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nsn.com> [wsa: added a newline] Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: designware: use {readl|writel}_relaxed instead of readl/writelJisheng Zhang2015-01-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | readl/writel is too expensive especially on Cortex A9 w/ outer L2 cache. This introduces i2c read/write delays on Marvell BG2/BG2Q SoCs when there are heavy L2 cache maintenance operations at the same time. The driver does not perform DMA, so it's safe to use the relaxed version. From another side, the relaxed io accessor macros are available on all architectures now, so we can use the relaxed versions instead. Signed-off-by: Jisheng Zhang <jszhang@marvell.com> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: designware-pci: no need to provide clk_khzAndy Shevchenko2015-01-23
| | | | | | | | | | | | | | | | | | | | The clk_khz field makes sense only if SS counters are not provided. Since we provide them for Haswell and Baytrail explicitly we may omit the clk_khz parameter. Reviewed-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: designware-pci: remove Moorestown supportAndy Shevchenko2015-01-23
| | | | | | | | | | | | | | | | | | The Moorestown support bits were removed few years ago. This is a follow up to that changes. Suggested-by: David Cohen <david.a.cohen@linux.intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: imx: whitespace and checkpatch cleanupPhilipp Zabel2015-01-22
| | | | | | | | | | | | | | | | | | This patch fixes up some whitespace issues and addresses a few checkpatch warnings. Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> Acked-by: Fugang Duan <B38611@freescale.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: simplify boilerplate code for attribute groupsWolfram Sang2015-01-22
| | | | | | | | | | | | | | | | Declaring attribute groups can be done with macros these days, let's use them for consistency and readability reasons. Also, put the ATTR macros directly below the referenced functions while we are here. Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: imx: remove unused return value assignmentsPhilipp Zabel2015-01-14
| | | | | | | | | | | | | | | | The ret variable is set and never used in the error path of i2c_imx_dma_request. Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> Acked-by: Fugang Duan <B38611@freescale.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: ACPI: Pick the first address if device has multipleMika Westerberg2015-01-14
| | | | | | | | | | | | | | | | | | | | | | | | ACPI specification allows I2C devices with multiple addresses. The current implementation goes over all addresses and assigns the last one to the device. This is typically not the primary address of the device. Instead of doing that we assign the first address to the device and then let the driver handle rest of the addresses as it wishes. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: cadence: Check for errata condition involving master receiveHarini Katakam2015-01-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Cadence I2C controller has the following bugs: - completion indication is not given to the driver at the end of a read/receive transfer with HOLD bit set. - Invalid read transaction are generated on the bus when HW timeout condition occurs with HOLD bit set. As a result of the above, if a set of messages to be transferred with repeated start includes any message following a read message, completion is never indicated and timeout occurs. Hence a check is implemented to return -EOPNOTSUPP for such sequences. Signed-off-by: Harini Katakam <harinik@xilinx.com> Signed-off-by: Vishnu Motghare <vishnum@xilinx.com> [wsa: fixed some whitespaces] Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: imx: fix handling of wait_for_completion_timeout resultNicholas Mc Guire2015-01-13
| | | | | | | | | | | | | | | | | | wait_for_completion_timeout does not return negative values so "result" handling here should be simplified to cover the actually possible cases only. Signed-off-by: Nicholas Mc Guire <der.herr@hofr.at> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: rk3x: Account for repeated start time requirementDoug Anderson2015-01-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On Rockchip I2C the controller drops SDA low slightly too soon to meet the "repeated start" requirements. >From my own experimentation over a number of rates: - controller appears to drop SDA at .875x (7/8) programmed clk high. - controller appears to keep SCL high for 2x programmed clk high. The first rule isn't enough to meet tSU;STA requirements in Standard-mode on the system I tested on. The second rule is probably enough to meet tHD;STA requirements in nearly all cases (especially after accounting for the first), but it doesn't hurt to account for it anyway just in case. Even though the repeated start requirement only need to be accounted for during a small part of the transfer, we'll adjust the timings for the whole transfer to meet it. I believe that adjusting the timings in just the right place to switch things up for repeated start would require several extra interrupts and that doesn't seem terribly worth it. With this change and worst case rise/fall times, I see 100kHz i2c going to ~85kHz. With slightly optimized rise/fall (800ns / 50ns) I see i2c going to ~89kHz. Fast-mode isn't affected much because tSU;STA is shorter relative to tHD;STA there. As part of this change we needed to account for the SDA falling time. The specification indicates that this should be the same, but we'll follow Designware's lead and add a binding. Note that we deviate from Designware and assign the default SDA falling time to be the same as the SCL falling time, which is incredibly likely. Signed-off-by: Doug Anderson <dianders@chromium.org> [wsa: rebased to i2c/for-next] Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: rk3x: fix bug that cause measured high_ns doesn't meet I2C specificationaddy ke2015-01-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The number of clock cycles to be written into the CLKDIV register that determines the I2C clk high phase includes the rise time. So to meet the timing requirements defined in the I2C specification which defines the minimal time SCL has to be high, the rise time has to taken into account. The same applies to the low phase with falling time. In my test on RK3288-Pink2 board, which is not an upstream board yet, if external pull-up resistor is 4.7K, rise_ns is about 700ns. So the measured high_ns is about 3900ns, which is less than 4000ns (the minimum high_ns in I2C specification for Standard-mode). To fix this bug min_low_ns should include fall time and min_high_ns should include rise time. This patch merged the patch from chromium project which can get the rise and fall times for signals from the device tree. This allows us to more accurately calculate timings. see: https://chromium-review.googlesource.com/#/c/232774/ Signed-off-by: Addy Ke <addy.ke@rock-chips.com> Reviewed-by: Doug Anderson <dianders@chromium.org> Tested-by: Doug Anderson <dianders@chromium.org> [wsa: fixed a typo in the docs] Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
| * i2c: cadence: Handle > 252 byte transfersHarini Katakam2015-01-13
| | | | | | | | | | | | | | | | | | | | | | | | | | The I2C controller sends a NACK to the slave when transfer size register reaches zero, irrespective of the hold bit. So, in order to handle transfers greater than 252 bytes, the transfer size register has to be maintained at a value >= 1. This patch implements the same. The interrupt status is cleared at the beginning of the isr instead of the end, to avoid missing any interrupts. Signed-off-by: Harini Katakam <harinik@xilinx.com> [wsa: added braces around else branch] Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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