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path: root/drivers/i2c/busses/i2c-designware-core.c
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2014-03-09i2c: designware: make SCL and SDA falling time configurableRomain Baeriswyl
This patch allows to set independantly SCL and SDA falling times. The tLOW period is computed by taking into account the SCL falling time. The tHIGH period is computed by taking into account the SDA falling time. For instance in case the margin on tLOW is considered too small, it can be increased by increasing the SCL falling time which is by default set at 300ns. The same applies for tHIGH period with the help of SDA falling time. Signed-off-by: Romain Baeriswyl <romainba@abilis.com> Reviewed-by: Christian Ruppert <christian.ruppert@abilis.com> Acked-by: Shinya Kuribayashi <skuribay@pobox.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-01-13i2c: designware: remove HAVE_CLK build dependecyBaruch Siach
Since 93abe8e4 (clk: add non CONFIG_HAVE_CLK routines) code using clk.h like this platform driver need not depend on HAVE_CLK. Also, remove a redundant clk.h include from core driver. Signed-off-by: Baruch Siach <baruch@tkos.co.il> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-11-15tree-wide: use reinit_completion instead of INIT_COMPLETIONWolfram Sang
Use this new function to make code more comprehensible, since we are reinitialzing the completion, not initializing. [akpm@linux-foundation.org: linux-next resyncs] Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Acked-by: Linus Walleij <linus.walleij@linaro.org> (personally at LCE13) Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-27i2c: designware: 10-bit addressing mode enabling if I2C_DYNAMIC_TAR_UPDATE ↵Chew, Chiau Ee
is set According to Designware I2C spec, if I2C_DYNAMIC_TAR_UPDATE is set to 1, the 10-bit addressing mode is controlled by IC_10BITADDR_MASTER bit of IC_TAR register instead of IC_CON register. The IC_10BITADDR_MASTER in IC_CON register becomes read-only copy. Since I2C_DYNAMIC_TAR_UPDATE value can't be detected from hardware register, so we will always set the IC_10BITADDR_MASTER bit in both IC_CON and IC_TAR register whenever 10-bit addresing mode is requested by user application. Signed-off-by: Chew, Chiau Ee <chiau.ee.chew@intel.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-08-28i2c: designware: make HCNT/LCNT values configurableMika Westerberg
The DesignWare I2C controller has high count (HCNT) and low count (LCNT) registers for each of the I2C speed modes (standard and fast). These registers are programmed based on the input clock speed in the driver. The current code calculates these values based on the input clock speed and tries hard to meet the I2C bus timing requirements. This could result non-optimal values with regarding to the bus speed. For example on Intel BayTrail we get bus speed of 315.41kHz which is ~20% slower than we would expect (400kHz) in fast mode (even though the timing requirements are met). This patch makes it possible for the platform code to pass more optimal HCNT/LCNT values to the core driver if they are known beforehand. If these are not set we use the calculated and more conservative values. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Acked-by: Shinya Kuribayashi <skuribay@pobox.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-08-07i2c: designware: Manually set RESTART bit between messagesChew, Chiau Ee
If both IC_EMPTYFIFO_HOLD_MASTER_EN and IC_RESTART_EN are set to 1, the Designware I2C controller doesn't generate RESTART unless user specifically requests it by setting RESTART bit in IC_DATA_CMD register. Since IC_EMPTYFIFO_HOLD_MASTER_EN setting can't be detected from hardware register, we must always manually set the restart bit between messages. Signed-off-by: Chew, Chiau Ee <chiau.ee.chew@intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-06-26i2c-designware: make SDA hold time configurableChristian Ruppert
This patch makes the SDA hold time configurable through device tree. Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com> Signed-off-by: Pierrick Hascoet <pierrick.hascoet@abilis.com> Acked-by: Vineet Gupta <vgupta@synopsys.com> for arch/arc bits Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-06-15i2c: designware: fix race between subsequent xfersChristian Ruppert
The designware block is not always properly disabled in the case of transfer errors. Interrupts from aborted transfers might be handled after the data structures for the following transfer are initialised but before the hardware is set up. This can corrupt the data structures to the point that the system is stuck in an infinite interrupt loop (where FIFOs are never emptied because dev->msg_read_idx == dev->msgs_num). This patch cleanly disables the designware-i2c hardware at the end of every transfer, be it successful or not. Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com> [wsa: extended the comment] Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-06-12i2c: designware: prevent signals from aborting I2C transfersMika Westerberg
If a process receives signal while it is waiting for I2C transfer to complete, an error is returned to the caller and the transfer is aborted. This can cause the driver to fail subsequent transfers. Also according to commit d295a86eab2 (i2c: mv64xxx: work around signals causing I2C transactions to be aborted) I2C drivers aren't supposed to abort transactions on signals. To prevent this switch to use wait_for_completion_timeout() instead of wait_for_completion_interruptible_timeout() in the designware I2C driver. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Christian Ruppert <christian.ruppert@abilis.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-05-17i2c: designware: always clear interrupts before enabling themMika Westerberg
If the I2C bus is put to a low power state by an ACPI method it might pull the SDA line low (as its power is removed). Once the bus is put to full power state again, the SDA line is pulled back to high. This transition looks like a STOP condition from the controller point-of-view which sets STOP detected bit in its status register causing the driver to fail subsequent transfers. Fix this by always clearing all interrupts before we start a transfer. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Cc: stable@kernel.org
2013-05-17i2c: designware: fix RX FIFO overrunJosef Ahmad
i2c_dw_xfer_msg() pushes a number of bytes to transmit/receive to/from the bus into the TX FIFO. For master-rx transactions, the maximum amount of data that can be received is calculated depending solely on TX and RX FIFO load. This is racy - TX FIFO may contain master-rx data yet to be processed, which will eventually land into the RX FIFO. This data is not taken into account and the function may request more data than the controller is actually capable of storing. This patch ensures the driver takes into account the outstanding master-rx data in TX FIFO to prevent RX FIFO overrun. Signed-off-by: Josef Ahmad <josef.ahmad@linux.intel.com> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Cc: stable@kernel.org
2013-04-15i2c-designware: switch to use runtime PM autosuspendMika Westerberg
Using autosuspend helps to reduce the resume latency in situations where another I2C message is going to be started soon. For example with HID over I2C touch panels we get several messages in a short period of time while the touch panel is in use. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-04-15i2c-designware: use usleep_range() in the busy-loopMika Westerberg
This is not an atomic context so there is no need to use mdelay() but instead use usleep_range(). Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-04-15i2c-designware: enable/disable the controller properlyMika Westerberg
The correct way to disable or enable the controller is to wait until the DW_IC_ENABLE_STATUS register bit matches the bit we program into DW_IC_ENABLE register. This procedure is described in the DesignWare I2C databook. By doing this we can be sure that the controller is in correct state once the function returns. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-01-28i2c-designware: always set the STOP bit after last byteMika Westerberg
If IC_EMPTYFIFO_HOLD_MASTER_EN is set to one, the DesignWare I2C controller doesn't generate STOP on the bus when the FIFO is empty. This violates the rules of Linux I2C stack as it requires that the STOP is issued once the i2c_transfer() is finished. However, there is no way to detect this from the hardware registers, so we must make sure that the STOP bit is always set once the last byte of the last message is transferred. This patch is based on the work of Dirk Brandewie. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2013-01-22i2c-designware: add missing MODULE_LICENSEMika Westerberg
The driver can also be built as a module so add MODULE_LICENSE for it. In addition add MODULE_DESCRIPTION as well. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2012-10-05i2c-designware: i2c_dw_xfer_msg can be staticJean Delvare
i2c_dw_xfer_msg is only called internally so it can be static. It original was, before the driver split. No idea why it was changed at that time. Signed-off-by: Jean Delvare <khali@linux-fr.org> Acked-by: Dirk Brandewie <dirk.brandewie@gmail.com>
2012-09-10i2c-designware: Fix build error if CONFIG_I2C_DESIGNWARE_PLATFORM=y && ↵Axel Lin
CONFIG_I2C_DESIGNWARE_PCI=y This patch adds config I2C_DESIGNWARE_CORE in Kconfig, and let I2C_DESIGNWARE_PLATFORM and I2C_DESIGNWARE_PCI select I2C_DESIGNWARE_CORE. Because both I2C_DESIGNWARE_PLATFORM and I2C_DESIGNWARE_PCI can be built as built-in or module, we also need to export the functions in i2c-designware-core. This fixes below build error when CONFIG_I2C_DESIGNWARE_PLATFORM=y && CONFIG_I2C_DESIGNWARE_PCI=y: LD drivers/i2c/busses/built-in.o drivers/i2c/busses/i2c-designware-pci.o: In function `i2c_dw_clear_int': i2c-designware-core.c:(.text+0xa10): multiple definition of `i2c_dw_clear_int' drivers/i2c/busses/i2c-designware-platform.o:i2c-designware-platdrv.c:(.text+0x928): first defined here drivers/i2c/busses/i2c-designware-pci.o: In function `i2c_dw_init': i2c-designware-core.c:(.text+0x178): multiple definition of `i2c_dw_init' drivers/i2c/busses/i2c-designware-platform.o:i2c-designware-platdrv.c:(.text+0x90): first defined here drivers/i2c/busses/i2c-designware-pci.o: In function `dw_readl': i2c-designware-core.c:(.text+0xe8): multiple definition of `dw_readl' drivers/i2c/busses/i2c-designware-platform.o:i2c-designware-platdrv.c:(.text+0x0): first defined here drivers/i2c/busses/i2c-designware-pci.o: In function `i2c_dw_isr': i2c-designware-core.c:(.text+0x724): multiple definition of `i2c_dw_isr' drivers/i2c/busses/i2c-designware-platform.o:i2c-designware-platdrv.c:(.text+0x63c): first defined here drivers/i2c/busses/i2c-designware-pci.o: In function `i2c_dw_xfer': i2c-designware-core.c:(.text+0x4b0): multiple definition of `i2c_dw_xfer' drivers/i2c/busses/i2c-designware-platform.o:i2c-designware-platdrv.c:(.text+0x3c8): first defined here drivers/i2c/busses/i2c-designware-pci.o: In function `i2c_dw_is_enabled': i2c-designware-core.c:(.text+0x9d4): multiple definition of `i2c_dw_is_enabled' drivers/i2c/busses/i2c-designware-platform.o:i2c-designware-platdrv.c:(.text+0x8ec): first defined here drivers/i2c/busses/i2c-designware-pci.o: In function `dw_writel': i2c-designware-core.c:(.text+0x124): multiple definition of `dw_writel' drivers/i2c/busses/i2c-designware-platform.o:i2c-designware-platdrv.c:(.text+0x3c): first defined here drivers/i2c/busses/i2c-designware-pci.o: In function `i2c_dw_xfer_msg': i2c-designware-core.c:(.text+0x2e8): multiple definition of `i2c_dw_xfer_msg' drivers/i2c/busses/i2c-designware-platform.o:i2c-designware-platdrv.c:(.text+0x200): first defined here drivers/i2c/busses/i2c-designware-pci.o: In function `i2c_dw_enable': i2c-designware-core.c:(.text+0x9c8): multiple definition of `i2c_dw_enable' drivers/i2c/busses/i2c-designware-platform.o:i2c-designware-platdrv.c:(.text+0x8e0): first defined here drivers/i2c/busses/i2c-designware-pci.o: In function `i2c_dw_read_comp_param': i2c-designware-core.c:(.text+0xa24): multiple definition of `i2c_dw_read_comp_param' drivers/i2c/busses/i2c-designware-platform.o:i2c-designware-platdrv.c:(.text+0x93c): first defined here drivers/i2c/busses/i2c-designware-pci.o: In function `i2c_dw_disable': i2c-designware-core.c:(.text+0x9dc): multiple definition of `i2c_dw_disable' drivers/i2c/busses/i2c-designware-platform.o:i2c-designware-platdrv.c:(.text+0x8f4): first defined here drivers/i2c/busses/i2c-designware-pci.o: In function `i2c_dw_func': i2c-designware-core.c:(.text+0x710): multiple definition of `i2c_dw_func' drivers/i2c/busses/i2c-designware-platform.o:i2c-designware-platdrv.c:(.text+0x628): first defined here drivers/i2c/busses/i2c-designware-pci.o: In function `i2c_dw_disable_int': i2c-designware-core.c:(.text+0xa18): multiple definition of `i2c_dw_disable_int' drivers/i2c/busses/i2c-designware-platform.o:i2c-designware-platdrv.c:(.text+0x930): first defined here make[3]: *** [drivers/i2c/busses/built-in.o] Error 1 make[2]: *** [drivers/i2c/busses] Error 2 make[1]: *** [drivers/i2c] Error 2 make: *** [drivers] Error 2 Signed-off-by: Axel Lin <axel.lin@gmail.com> Signed-off-by: Jean Delvare <khali@linux-fr.org> Tested-by: Jiri Slaby <jslaby@suse.cz> Cc: stable@vger.kernel.org [3.2+]
2012-05-12i2c: designware: Add support for 16bit register accessStefan Roese
The STM SPEAr platform can only access the i2c controller register via 16bit read/write functions. This patch adds support to automatically detect this 16bit access mode. Signed-off-by: Stefan Roese <sr@denx.de> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2011-10-29i2c-designware: Add runtime power management supportDirk Brandewie
Add runtime power management to the PCI driver. Signed-off-by: Dirk Brandewie <dirk.brandewie@gmail.com> Signed-off-by: Ben Dooks <ben-linux@fluff.org>
2011-10-29i2c-designware: Push all register reads/writes into the core code.Dirk Brandewie
Move all register manipulation code into the core, also move register offset definitions to i2c-designware-core.c since the bus specific portions of the driver no longer need/use them. Signed-off-by: Dirk Brandewie <dirk.brandewie@gmail.com> Signed-off-by: Ben Dooks <ben-linux@fluff.org>
2011-10-29i2c-designware: Support multiple cores using same ISRDirk Brandewie
Add check to make sure that the core is enabled and has outstanding interrupts. The activity bit is masked due to the fact that it will stay active even after the controller has been disabled until the contoller internal state machines have settled. Signed-off-by: Dirk Brandewie <dirk.brandewie@gmail.com> Signed-off-by: Ben Dooks <ben-linux@fluff.org>
2011-10-29i2c-designware: move controller config to bus specific portion of driverDirk Brandewie
With multiple I2C adapters possible in the system each running at (possibly) different speeds we need to move the controller configuration bit field to the adapter. Signed-off-by: Dirk Brandewie <dirk.brandewie@gmail.com> Signed-off-by: Ben Dooks <ben-linux@fluff.org>
2011-10-29i2c-designware: move i2c functionality bit field to be adapter specificDirk Brandewie
The functionality of the adapter depends on the configuration of the IP block at silicon compile time and is adapter specific. Signed-off-by: Dirk Brandewie <dirk.brandewie@gmail.com> Signed-off-by: Ben Dooks <ben-linux@fluff.org>
2011-10-29i2c-designware: Move retriveving the clock speed out of core code.Dirk Brandewie
The clock frequecy supplied to the IP core is specific to a single instance of the driver. This patch makes it possible to have multiple Designware I2C cores in the system possibly running at different core frequencies. Signed-off-by: Dirk Brandewie <dirk.brandewie@gmail.com> Signed-off-by: Ben Dooks <ben-linux@fluff.org>
2011-10-29i2c-designware: split of i2c-designware.c into core and bus specific partsDirk Brandewie
This patch splits i2c-designware.c into three pieces: i2c-designware-core.c, contains the code that interacts directly with the core. i2c-designware-platdrv.c, contains the code specific to the platform driver using the core. i2c-designware-core.h contains the definitions and declareations shared by i2c-designware-core.c and i2c-designware-platdrv.c. This patch is the first in a set to allow multiple instances of the designware I2C core in the system. Signed-off-by: Dirk Brandewie <dirk.brandewie@gmail.com> Signed-off-by: Ben Dooks <ben-linux@fluff.org>