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2014-03-12i2c: s3c2410: Leave the bus disabled unless it is in useSimon Glass
There is a rather odd feature of the exynos i2c controller that if it is left enabled, it can lock itself up with the clk line held low. This makes the bus unusable. Unfortunately, the s3c24xx_i2c_set_master() function does not notice this, and reports a timeout. From then on the bus cannot be used until the AP is rebooted. The problem happens when any sort of interrupt occurs (e.g. due to a bus transition) when we are not in the middle of a transaction. We have seen many instances of this when U-Boot leaves the bus apparently happy, but Linux cannot access it. The current code is therefore pretty fragile. This fixes things by leaving the bus disabled unless we are actually in a transaction. We enable the bus at the start of the transaction and disable it at the end. That way we won't get interrupts and will not lock up the bus. It might be possible to clear pending interrupts on start-up, but this seems to be a more robust solution. We can't service interrupts when we are not in a transaction, and anyway would rather not lock up the bus while we try. Signed-off-by: Simon Glass <sjg@chromium.org> Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com> Acked-by: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-03-12i2c: i2c-s3c2410: deprecate class based instantiationWolfram Sang
Warn users that class based instantiation is going away soon in favour of more robust probing and faster bootup times. Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Cc: Ben Dooks <ben-linux@fluff.org> Cc: Kukjin Kim <kgene.kim@samsung.com>
2014-01-16i2c: s3c2410: fix quirk usage for 64-bitPankaj Dubey
If used 64 bit compiler GCC warns that: drivers/i2c/busses/i2c-s3c2410.c: In function ‘s3c24xx_get_device_quirks’: drivers/i2c/busses/i2c-s3c2410.c:168:10: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast] This patch fixes this by converting "unsigned int" to "kernel_ulong_t". Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-01-03i2c: s3c2410: dont need CPU_FREQ transitions for exynos seriesNaveen Krishna Ch
For Exynos4 and Exynos5 SoCs from Samsung the i2c clock is based on a fixed 66 MHz peripheral clock, and therefore is completely independent of the cpu frequency. Thus, registering for a CPU freq notifier is very wasteful. This patch modifes the code such that, i2c bus registers to cpu_freq_transition only if CONFIG_CPU_FREQ_S3C24XX is enabled. This change should save a bunch of cpufreq transitions calls which does not apply to exynos SoCs. Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com> Acked-by: Kyungmin Park <kyungmin.park@samsung.com> Reviewed-by: Doug Anderson <dianders@chromium.org> Reviewed-by: Tomasz Figa <t.figa@samsung.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-01-03i2c: s3c2410: Add polling mode supportVasanth Ananthan
This patch adds polling mode support for i2c-s3c2410 driver.The SATA PHY controller's CMU and TRSV block's are of I2C register map in exynos5250.These blocks can be configured using i2c. But i2c controller instance on which these block's sits lacks an interrupt line.Also the current i2c-s3c2410 driver is only interrupt driven, thus a polling mode support is required in the driver for supporting this controller. This patch adds this support to the driver. Signed-off-by: Vasanth Ananthan <vasanth.a@samsung.com> Signed-off-by: Yuvaraj Kumar C D <yuvaraj.cd@samsung.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-10-30i2c: Include linux/of.h headerSachin Kamat
'of_match_ptr' is defined in linux/of.h. Include it explicitly to avoid build breakage in the future. Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-09-27i2c: s3c2410: fix clk_disable/clk_unprepare WARNingsKim Phillips
commit d16933b33914a6dff38a4ecbe8edce44a17898e8 "i2c: s3c2410: Move location of clk_prepare_enable() call in probe function" refactored clk_enable and clk_disable calls yet neglected to remove the clk_disable_unprepare call in the module's remove(). It helps remove warnings on an arndale during unbind: echo 12c90000.i2c > /sys/bus/platform/devices/12c90000.i2c/driver/unbind ------------[ cut here ]------------ WARNING: CPU: 0 PID: 2548 at drivers/clk/clk.c:842 clk_disable+0x18/0x24() Modules linked in: CPU: 0 PID: 2548 Comm: bash Not tainted 3.11.0-next-20130916-00003-gf4bddbc #6 [<c0014d48>] (unwind_backtrace+0x0/0xf8) from [<c00117d0>] (show_stack+0x10/0x14) [<c00117d0>] (show_stack+0x10/0x14) from [<c0361be8>] (dump_stack+0x6c/0xac) [<c0361be8>] (dump_stack+0x6c/0xac) from [<c001d864>] (warn_slowpath_common+0x64/0x88) [<c001d864>] (warn_slowpath_common+0x64/0x88) from [<c001d8a4>] (warn_slowpath_null+0x1c/0x24) [<c001d8a4>] (warn_slowpath_null+0x1c/0x24) from [<c02c4a64>] (clk_disable+0x18/0x24) [<c02c4a64>] (clk_disable+0x18/0x24) from [<c028d0b0>] (s3c24xx_i2c_remove+0x28/0x70) [<c028d0b0>] (s3c24xx_i2c_remove+0x28/0x70) from [<c0217a10>] (platform_drv_remove+0x18/0x1c) [<c0217a10>] (platform_drv_remove+0x18/0x1c) from [<c0216358>] (__device_release_driver+0x58/0xb4) [<c0216358>] (__device_release_driver+0x58/0xb4) from [<c02163d0>] (device_release_driver+0x1c/0x28) [<c02163d0>] (device_release_driver+0x1c/0x28) from [<c02153c0>] (unbind_store+0x58/0x90) [<c02153c0>] (unbind_store+0x58/0x90) from [<c0214c90>] (drv_attr_store+0x20/0x2c) [<c0214c90>] (drv_attr_store+0x20/0x2c) from [<c01032c0>] (sysfs_write_file+0x168/0x198) [<c01032c0>] (sysfs_write_file+0x168/0x198) from [<c00ae1c0>] (vfs_write+0xb0/0x194) [<c00ae1c0>] (vfs_write+0xb0/0x194) from [<c00ae594>] (SyS_write+0x3c/0x70) [<c00ae594>] (SyS_write+0x3c/0x70) from [<c000e3e0>] (ret_fast_syscall+0x0/0x30) ---[ end trace 4c9f9403066f57a6 ]--- ------------[ cut here ]------------ WARNING: CPU: 0 PID: 2548 at drivers/clk/clk.c:751 clk_unprepare+0x14/0x1c() Modules linked in: CPU: 0 PID: 2548 Comm: bash Tainted: G W 3.11.0-next-20130916-00003-gf4bddbc #6 [<c0014d48>] (unwind_backtrace+0x0/0xf8) from [<c00117d0>] (show_stack+0x10/0x14) [<c00117d0>] (show_stack+0x10/0x14) from [<c0361be8>] (dump_stack+0x6c/0xac) [<c0361be8>] (dump_stack+0x6c/0xac) from [<c001d864>] (warn_slowpath_common+0x64/0x88) [<c001d864>] (warn_slowpath_common+0x64/0x88) from [<c001d8a4>] (warn_slowpath_null+0x1c/0x24) [<c001d8a4>] (warn_slowpath_null+0x1c/0x24) from [<c02c5834>] (clk_unprepare+0x14/0x1c) [<c02c5834>] (clk_unprepare+0x14/0x1c) from [<c028d0b8>] (s3c24xx_i2c_remove+0x30/0x70) [<c028d0b8>] (s3c24xx_i2c_remove+0x30/0x70) from [<c0217a10>] (platform_drv_remove+0x18/0x1c) [<c0217a10>] (platform_drv_remove+0x18/0x1c) from [<c0216358>] (__device_release_driver+0x58/0xb4) [<c0216358>] (__device_release_driver+0x58/0xb4) from [<c02163d0>] (device_release_driver+0x1c/0x28) [<c02163d0>] (device_release_driver+0x1c/0x28) from [<c02153c0>] (unbind_store+0x58/0x90) [<c02153c0>] (unbind_store+0x58/0x90) from [<c0214c90>] (drv_attr_store+0x20/0x2c) [<c0214c90>] (drv_attr_store+0x20/0x2c) from [<c01032c0>] (sysfs_write_file+0x168/0x198) [<c01032c0>] (sysfs_write_file+0x168/0x198) from [<c00ae1c0>] (vfs_write+0xb0/0x194) [<c00ae1c0>] (vfs_write+0xb0/0x194) from [<c00ae594>] (SyS_write+0x3c/0x70) [<c00ae594>] (SyS_write+0x3c/0x70) from [<c000e3e0>] (ret_fast_syscall+0x0/0x30) ---[ end trace 4c9f9403066f57a7 ]--- Signed-off-by: Kim Phillips <kim.phillips@linaro.org> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-08-23i2c: move OF helpers into the coreWolfram Sang
I2C of helpers used to live in of_i2c.c but experience (from SPI) shows that it is much cleaner to have this in the core. This also removes a circular dependency between the helpers and the core, and so we can finally register child nodes in the core instead of doing this manually in each driver. So, fix the drivers and documentation, too. Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-08-19i2c: use dev_get_platdata()Jingoo Han
Use the wrapper function for retrieving the platform data instead of accessing dev->platform_data directly. Signed-off-by: Jingoo Han <jg1.han@samsung.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-05-18drivers/i2c/busses: don't check resource with devm_ioremap_resourceWolfram Sang
devm_ioremap_resource does sanity checks on the given resource. No need to duplicate this in the driver. Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Acked-by: Stephen Warren <swarren@nvidia.com> Acked-by: Barry Song <Baohua.Song@csr.com>
2013-04-09i2c: s3c2410: Add SMBus emulation for block readJaemin Yoo
SMBus read and write are supported by the emulation layer of i2c framework if the controller doesn't have SMBus features. I2C_M_RECV_LEN flag is used to let i2c drivers know rx length is not yet determined but will be read to the first byte in rx buffer. s3c2410 doesn't handle this flag. So only one byte is read from slave. There fore following two features are added to the driver code. 1. skip rx length check if I2C_M_RECV_LEN is set and the length is 1. 2. add actual bytes to the rx length after reading first bytes if I2C_M_RECV_LEN. I2C_M_RECV_LEN is only set for SMBus command. So this code does not affect legacy codes which only use i2c command for s3c2410. Signed-off-by: Jaemin Yoo <jmin.yoo@samsung.com> Tested-by: Prasanna Kumar <prasanna.ps@samsung.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-03-24i2c: s3c2410: fixup the styling of the newly moved register definitionsHeiko Stübner
Make them conform more to established standards. Signed-off-by: Heiko Stuebner <heiko@sntech.de> Acked-by: Kukjin Kim <kgene.kim@samsung.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-03-24i2c: s3c2410: move mach/regs-iic.h into i2c-s3c2410 device driverHeiko Stübner
The register definitions are only used in the driver itself. This also removes the last dependency on plat/ includes from the i2c driver. Signed-off-by: Heiko Stuebner <heiko@sntech.de> Acked-by: Kukjin Kim <kgene.kim@samsung.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-02-26Merge branch 'i2c/for-next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux Pull i2c updates from Wolfram Sang: "Highlights: - new drivers for Intel ismt & Broadcom bcm2835 - a number of drivers got support for more variants and mostly got cleaned up on the way (sis630, i801, at91, tegra, designware) - i2c got rid of all *_set_drvdata(..., NULL) on remove/probe failure - removed the i2c_smbus_process_call from the core since there are no users - mxs can now switch between PIO and DMA depending on the message size and the bus speed can now be arbitrary In addition, there is the usual bunch of fixes, cleanups, devm_* conversions, etc" Fixed conflict (and buggy devm_* conversion) in i2c-s3c2410.c * 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (39 commits) i2c: Remove unneeded xxx_set_drvdata(..., NULL) calls i2c: pxa: remove incorrect __exit annotations i2c: ocores: Fix pointer to integer cast warning i2c: tegra: remove warning dump if timeout happen in transfer i2c: fix i2c-ismt.c printk format warning i2c: i801: Add Device IDs for Intel Wellsburg PCH i2c: add bcm2835 driver i2c: ismt: Add Seth and Myself as maintainers i2c: sis630: checkpatch cleanup i2c: sis630: display unsigned hex i2c: sis630: use hex to constants for SMBus commands i2c: sis630: fix behavior after collision i2c: sis630: clear sticky bits i2c: sis630: Add SIS964 support i2c: isch: Add module parameter for backbone clock rate if divider is unset i2c: at91: fix unsed variable warning when building with !CONFIG_OF i2c: Adding support for Intel iSMT SMBus 2.0 host controller i2c: sh_mobile: don't send a stop condition by default inside transfers i2c: sh_mobile: eliminate an open-coded "goto" loop i2c: sh_mobile: fix timeout error handling ...
2013-01-28i2c: s3c2410: Add quirk to exclude GPIO config for exynos5440Giridhar Maruthy
Signed-off-by: Giridhar Maruthy <giridhar.m@samsung.com> Signed-off-by: Kukjin Kim <kgene.kim@samsung.com> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2013-01-28i2c: s3c2410: Remove err_cpufreq labelTushar Behera
err_cpufreq label is now used only once. It can be removed and related code can be moved to the caller location. Signed-off-by: Tushar Behera <tushar.behera@linaro.org> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2013-01-28i2c: s3c2410: Move location of clk_prepare_enable() call in probe functionTushar Behera
In i2c-s3c2410 driver probe, only s3c24xx_i2c_init() needs the I2C clock to be enabled. Moving clk_prepare_enable() and clk_disable_unprepare() calls to around this function simplifies the return path of probe call. Signed-off-by: Tushar Behera <tushar.behera@linaro.org> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2013-01-28i2c: s3c2410: Convert to use devm_* APIsTushar Behera
i2c-s3c2410 driver is modified to use devm_clk_get() and devm_request_irq(). This also simplifies the return path in driver's probe. Signed-off-by: Tushar Behera <tushar.behera@linaro.org> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2013-01-28i2c: s3c2410: Remove unnecessary label err_noclkTushar Behera
err_noclk label redirects to a simple return statement. Move the return statement to the caller location and remove the label. Signed-off-by: Tushar Behera <tushar.behera@linaro.org> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2013-01-24i2c: Convert to devm_ioremap_resource()Thierry Reding
Convert all uses of devm_request_and_ioremap() to the newly introduced devm_ioremap_resource() which provides more consistent error handling. devm_ioremap_resource() provides its own error messages so all explicit error messages can be removed from the failure code paths. Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de> Acked-by: Wolfram Sang <w.sang@pengutronix.de> Cc: Ben Dooks <ben-linux@fluff.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-12-18Merge branch 'i2c-embedded/for-next' of git://git.pengutronix.de/git/wsa/linuxLinus Torvalds
Pull i2c-embedded changes from Wolfram Sang: - CBUS driver (an I2C variant) - continued rework of the omap driver - s3c2410 gets lots of fixes and gains pinctrl support - at91 gains DMA support - the GPIO muxer gains devicetree probing - typical fixes and additions all over * 'i2c-embedded/for-next' of git://git.pengutronix.de/git/wsa/linux: (45 commits) i2c: omap: Remove the OMAP_I2C_FLAG_RESET_REGS_POSTIDLE flag i2c: at91: add dma support i2c: at91: change struct members indentation i2c: at91: fix compilation warning i2c: mxs: Do not disable the I2C SMBus quick mode i2c: mxs: Handle i2c DMA failure properly i2c: s3c2410: Remove recently introduced performance overheads i2c: ocores: Move grlib set/get functions into #ifdef CONFIG_OF block i2c: s3c2410: Add fix for i2c suspend/resume i2c: s3c2410: Fix code to free gpios i2c: i2c-cbus-gpio: introduce driver i2c: ocores: Add support for the GRLIB port of the controller and use function pointers for getreg and setreg functions i2c: ocores: Add irq support for sparc i2c: omap: Move the remove constraint ARM: dts: cfa10049: Add the i2c muxer buses to the CFA-10049 i2c: s3c2410: do not special case HDMIPHY stuck bus detection i2c: s3c2410: use exponential back off while polling for bus idle i2c: s3c2410: do not generate STOP for QUIRK_HDMIPHY i2c: s3c2410: grab adapter lock while changing i2c clock i2c: s3c2410: Add support for pinctrl ...
2012-12-13Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial Pull trivial branch from Jiri Kosina: "Usual stuff -- comment/printk typo fixes, documentation updates, dead code elimination." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits) HOWTO: fix double words typo x86 mtrr: fix comment typo in mtrr_bp_init propagate name change to comments in kernel source doc: Update the name of profiling based on sysfs treewide: Fix typos in various drivers treewide: Fix typos in various Kconfig wireless: mwifiex: Fix typo in wireless/mwifiex driver messages: i2o: Fix typo in messages/i2o scripts/kernel-doc: check that non-void fcts describe their return value Kernel-doc: Convention: Use a "Return" section to describe return values radeon: Fix typo and copy/paste error in comments doc: Remove unnecessary declarations from Documentation/accounting/getdelays.c various: Fix spelling of "asynchronous" in comments. Fix misspellings of "whether" in comments. eisa: Fix spelling of "asynchronous". various: Fix spelling of "registered" in comments. doc: fix quite a few typos within Documentation target: iscsi: fix comment typos in target/iscsi drivers treewide: fix typo of "suport" in various comments and Kconfig treewide: fix typo of "suppport" in various comments ...
2012-11-22i2c: s3c2410: Remove recently introduced performance overheadsMark Brown
The changes in "i2c-s3c2410: use exponential back off while polling for bus idle" remove the initial busy wait for I2C transfers to complete and replace it with usleep_range() calls which will schedule. Since for older SoCs I2C transfers would usually complete within an extremely small number of CPU cycles there is a win from not having to schedule. This happens because on the older SoCs the cores run at a smaller multiple of the speeds that the I2C bus is operating at; on more modern SoCs the busy wait is less likely to be effective. Fix the issue by restoring the busy wait, reducing the number of spins from 20 to 3 which covers the overwhelming majority of I2C transfers on the SoCs where the busy wait is effective. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Acked-by: Olof Johansson <olof@lixom.net> Reviewed-by: Daniel Kurtz <djkurtz@chromium.org> Reviewed-by: Doug Anderson <dianders@chromium.org> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2012-11-19Fix misspellings of "whether" in comments.Adam Buchbinder
"Whether" is misspelled in various comments across the tree; this fixes them. No code changes. Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-11-19i2c: s3c2410: Fix code to free gpiosAbhilash Kesavan
Store the requested gpios so that they can be freed on error/removal. Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2012-11-19i2c: s3c2410: Add fix for i2c suspend/resumeAbhilash Kesavan
The I2C driver makes a gpio_request during initialization. This request happens again on resume and fails due to the earlier successful request. Re-factor the code to only initialize the gpios during probe. Errors on resume without this: [ 16.020000] s3c-i2c s3c2440-i2c.0: gpio [42] request failed [ 16.020000] s3c-i2c s3c2440-i2c.1: gpio [44] request failed [ 16.020000] s3c-i2c s3c2440-i2c.2: gpio [6] request failed Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2012-11-19i2c: s3c2410: Fix code to free gpiosAbhilash Kesavan
Store the requested gpios so that they can be freed on error/removal. Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2012-11-16i2c: s3c2410: do not special case HDMIPHY stuck bus detectionDaniel Kurtz
Commit "i2c-s3c2410: Add HDMIPHY quirk for S3C2440" added support for HDMIPHY with some special handling in s3c24xx_i2c_set_master: "due to unknown reason (probably HW bug in HDMIPHY and/or the controller) a transfer fails to finish. The controller hangs after sending the last byte, the workaround for this bug is resetting the controller after each transfer" The "unknown reason" was that the proper sequence for generating a STOP condition wasn't being followed as per the datasheet. Since this is fixed by "PATCH: i2c-s3c2410: do not generate STOP for QUIRK_HDMIPHY buses", remove the special handling. Signed-off-by: Daniel Kurtz <djkurtz@chromium.org> Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2012-11-16i2c: s3c2410: use exponential back off while polling for bus idleDaniel Kurtz
Usually, the i2c controller has finished emitting the i2c STOP before the driver reaches the bus idle polling loop. Optimize for this most common case by reading IICSTAT first and potentially skipping the loop. If the cpu is faster than the hardware, we wait for bus idle in a polling loop. However, since the duration of one iteration of the loop is dependent on cpu freq, and this i2c IP is used on many different systems, use a time based loop timeout (5 ms). We would like very low latencies to detect bus idle for the normal 'fast' case. However, if a device is slow to release the bus for some reason, it could hold off the STOP generation for up to several milliseconds. Rapidly polling for bus idle would seriously load the CPU while waiting for it to release the bus. So, use a partial exponential backoff as a compromise between idle detection latency and cpu load. Signed-off-by: Daniel Kurtz <djkurtz@chromium.org> Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2012-11-16i2c: s3c2410: do not generate STOP for QUIRK_HDMIPHYDaniel Kurtz
The datasheet says that the STOP sequence should be: 1) I2CSTAT.5 = 0 - Clear BUSY (or 'generate STOP') 2) I2CCON.4 = 0 - Clear IRQPEND 3) Wait until the stop condition takes effect. 4*) I2CSTAT.4 = 0 - Clear TXRXEN Where, step "4*" is only for buses with the "HDMIPHY" quirk. However, after much experimentation, it appears that: a) normal buses automatically clear BUSY and transition from Master->Slave when they complete generating a STOP condition. Therefore, step (3) can be done in doxfer() by polling I2CCON.4 after starting the STOP generation here. b) HDMIPHY bus does neither, so there is no way to do step 3. There is no indication when this bus has finished generating STOP. In fact, we have found that as soon as the IRQPEND bit is cleared in step 2, the HDMIPHY bus generates the STOP condition, and then immediately starts transferring another data byte, even though the bus is supposedly stopped. This is presumably because the bus is still in "Master" mode, and its BUSY bit is still set. To avoid these extra post-STOP transactions on HDMI phy devices, we just disable Serial Output on the bus (I2CSTAT.4 = 0) directly, instead of first generating a proper STOP condition. This should float SDA & SCK terminating the transfer. Subsequent transfers start with a proper START condition, and proceed normally. The HDMIPHY bus is an internal bus that always has exactly two devices, the host as Master and the HDMIPHY device as the slave. Skipping the STOP condition has been tested on this bus and works. Also, since we disable the bus directly from the isr, we can skip the bus idle polling loop at the end of doxfer(). Signed-off-by: Daniel Kurtz <djkurtz@chromium.org> Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2012-11-16i2c: s3c2410: grab adapter lock while changing i2c clockDaniel Kurtz
We probably don't want to change I2C frequency while a transfer is in progress. The current implementation grabs a spinlock, but that only protected the writes to IICCON when starting a message, it didn't protect against clock changes in the middle of a transaction. Note: The i2c-core already grabs the adapter lock before calling s3c24xx_i2c_doxfer(), which ensures that only one caller is issuing a xfer at a time. This means it is not necessary to disable interrupts (spin_lock_irqsave) when changing frequencies, since there won't be any i2c interrupts if there is no on-going xfer. Lastly, i2c_lock_adapter() may cause the cpufreq_transition to sleep if if a xfer is in progress, but this is ok since cpufreq notifiers are called in a kernel thread, and there are already cases where it could sleep, such as when using i2c to update the output of a voltage regulator. Note: the cpufreq part of this change has no functional affect on exynos, where the i2c clock is independent of the cpufreq. But, there is a slight perfomance boost since we no longer need to lock/unlock an additional spinlock. Signed-off-by: Daniel Kurtz <djkurtz@chromium.org> Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2012-11-16i2c: s3c2410: Add support for pinctrlTomasz Figa
This patch adds support for pin configuration using pinctrl subsystem to the i2c-s3c2410 driver. Signed-off-by: Tomasz Figa <t.figa@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2012-11-16i2c: s3c2410: Convert to devm_request_and_ioremap()Mark Brown
A small code saving and less error handling to worry about. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2012-11-16i2c: s3c2410: Refactor ifdefs for PM_SLEEPMark Brown
Use the PM_SLEEP ifdef for system suspend and resume. This is partly in preparation for adding runtime operations and partly because a user may in theory choose to enable runtime suspend but not system suspend. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Reviewed-by: Shubhrajyoti D <shubhrajyoti@ti.com> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2012-10-11Merge branch 'i2c-embedded/for-next' of git://git.pengutronix.de/git/wsa/linuxLinus Torvalds
Pull i2c-embedded changes from Wolfram Sang: "The changes for i2c-embedded include: - massive rework of the omap driver - massive rework of the at91 driver. In fact, the old driver gets removed; I am okay with this approach since the old driver was depending on BROKEN and its limitations made it practically unusable, so people used bitbanging instead. But even if there are users, there is no platform_data or module parameter which would need to be converted. It is just another driver doing I2C transfers, just way better. Modifications of arch/arm/at91 related files have proper acks from the maintainer. - new driver for R-Car I2C - devicetree and generic_clock conversions and fixes - usual driver fixes and changes. The rework patches have come a long way and lots of people have been involved in creating/testing them. Most patches have been in linux-next at least since 3.6-rc5. A few have been added in the last week, I have to admit. An unexpected (but welcome :)) peak in private life is the cause for that. The "late" patches shouldn't cause any merge conflicts and I will have a special eye on them during the stabilization phase. This is an exception and I want to have the patches in place properly in time again for the next kernels." * 'i2c-embedded/for-next' of git://git.pengutronix.de/git/wsa/linux: (44 commits) MXS: Implement DMA support into mxs-i2c i2c: add Renesas R-Car I2C driver i2c: s3c2410: use clk_prepare_enable and clk_disable_unprepare ARM: OMAP: convert I2C driver to PM QoS for MPU latency constraints i2c: nomadik: Add Device Tree support to the Nomadik I2C driver i2c: algo: pca: Fix chip reset function for PCA9665 i2c: mpc: Wait for STOP to hit the bus i2c: davinci: preparation for switch to common clock framework omap-i2c: fix incorrect log message when using a device tree i2c: omap: sanitize exit path i2c: omap: switch over to autosuspend API i2c: omap: remove unnecessary pm_runtime_suspended check i2c: omap: switch to threaded IRQ support i2c: omap: remove redundant status read i2c: omap: get rid of the "complete" label i2c: omap: resize fifos before each message i2c: omap: simplify IRQ exit path i2c: omap: always return IRQ_HANDLED i2c: omap: simplify errata check i2c: omap: bus: add a receiver flag ...
2012-10-06i2c: s3c2410: use clk_prepare_enable and clk_disable_unprepareThomas Abraham
Convert clk_enable/clk_disable to clk_prepare_enable/clk_disable_unprepare calls as required by common clock framework. Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2012-09-19ARM: samsung: move platform_data definitionsArnd Bergmann
Platform data for device drivers should be defined in include/linux/platform_data/*.h, not in the architecture and platform specific directories. This moves such data out of the samsung include directories Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com> Cc: Kukjin Kim <kgene.kim@samsung.com> Cc: Kyungmin Park <kyungmin.park@samsung.com> Cc: Ben Dooks <ben-linux@fluff.org> Cc: Jeff Garzik <jgarzik@pobox.com> Cc: Guenter Roeck <linux@roeck-us.net> Cc: "Wolfram Sang (embedded platforms)" <w.sang@pengutronix.de> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Bryan Wu <bryan.wu@canonical.com> Cc: Richard Purdie <rpurdie@rpsys.net> Cc: Sylwester Nawrocki <s.nawrocki@samsung.com> Cc: Chris Ball <cjb@laptop.org> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Grant Likely <grant.likely@secretlab.ca> Cc: Felipe Balbi <balbi@ti.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Sangbeom Kim <sbkim73@samsung.com> Cc: Liam Girdwood <lrg@ti.com> Cc: linux-samsung-soc@vger.kernel.org
2012-07-13i2c-s3c2410: Use plain pm_runtime_put()Mark Brown
There's no point in using _sync() as we don't really care if the suspend has completed immediately. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Reviewed-by: Shubhrajyoti D <shubhrajyoti@ti.com> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2012-07-13i2c: s3c2410: Fix pointer type passed to of_match_node()Karol Lewandowski
This commit fixes warning introduced in 27452498a ("i2c-s3c2410: Rework device type handling"): drivers/i2c/busses/i2c-s3c2410.c: In function 's3c24xx_get_device_quirks': drivers/i2c/busses/i2c-s3c2410.c:125: warning: passing argument 1 of 'of_match_node' from incompatible pointer type include/linux/of.h:245: note: expected 'const struct of_device_id *' but argument is of type 'const struct of_device_id (*)[4]' Signed-off-by: Karol Lewandowski <k.lewandowsk@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2012-05-30i2c: Split I2C_M_NOSTART support out of I2C_FUNC_PROTOCOL_MANGLINGMark Brown
Since there are uses for I2C_M_NOSTART which are much more sensible and standard than most of the protocol mangling functionality (the main one being gather writes to devices where something like a register address needs to be inserted before a block of data) create a new I2C_FUNC_NOSTART for this feature and update all the users to use it. Also strengthen the disrecommendation of the protocol mangling while we're at it. In the case of regmap-i2c we remove the requirement for mangling as I2C_M_NOSTART is the only mangling feature which is being used. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Acked-by: Wolfram Sang <w.sang@pengutronix.de> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-05-12i2c-s3c2410: Add HDMIPHY quirk for S3C2440Karol Lewandowski
This patch adds support for s3c2440 I2C bus controller dedicated HDMIPHY device on Exynos4 platform. Some quirks are introduced due to differences between HDMIPHY and other I2C controllers on Exynos4. These differences are: - no GPIOs, HDMIPHY is inside the SoC and the controller is connected internally - due to unknown reason (probably HW bug in HDMIPHY and/or the controller) a transfer fails to finish. The controller hangs after sending the last byte, the workaround for this bug is resetting the controller after each transfer Signed-off-by: Tomasz Stanislawski <t.stanislaws@samsung.com> Signed-off-by: Karol Lewandowski <k.lewandowsk@samsung.com> Tested-by: Tomasz Stanislawski <t.stanislaws@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2012-05-12i2c-s3c2410: Rework device type handlingKarol Lewandowski
Reorganize driver a bit to better handle device tree-based systems: - move machine type to driver's private structure instead of quering platform device variants in runtime - replace s3c24xx_i2c_type enum with unsigned int that holds bitmask with revision-specific quirks Signed-off-by: Karol Lewandowski <k.lewandowsk@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2012-05-12i2c-s3c2410: Drop unused defineKarol Lewandowski
Use standard of_match_ptr() to avoid defining variable unused in non device tree builds. Signed-off-by: Karol Lewandowski <k.lewandowsk@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Acked-by: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2012-03-07i2c-s3c2410: Add stub runtime power managementMark Brown
Add stub runtime_pm calls which go through the flow of enabling and disabling but don't actually do anything with the device itself as there's nothing useful we can do. This provides the core PM framework with information about when the device is idle, enabling chip wide power savings. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Acked-by: Heiko Stuebner <heiko@sntech.de> Signed-off-by: Ben Dooks <ben-linux@fluff.org> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2012-03-07i2c-s3c2410: Convert to devm_kzalloc()Mark Brown
Saves remembering to call kfree(). There's some kfree()s used by the resource still, these will be removed in 3.3 using the newly added devm_request_and_ioremap(). Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Ben Dooks <ben-linux@fluff.org> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2011-12-18i2c-s3c2410: Fix return code of s3c24xx_i2c_parse_dt_gpioTushar Behera
s3c24xx_i2c_parse_dt_gpio is called when cfg_gpio is not defined in the platform data of the i2c device. When DT is not enabled, the above function always returns -EINVAL. Since there can be some i2c devices which don't need to configure any gpio lines, the probe of such devices would fail here. Changing the default return value to success would fix this issue. Signed-off-by: Tushar Behera <tushar.behera@linaro.org> Signed-off-by: Ben Dooks <ben-linux@fluff.org>
2011-12-18i2c: i2c-s3c2410: Add a cpu_relax() to busy wait for bus idleMark Brown
Be a bit more friendly. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Ben Dooks <ben-linux@fluff.org>
2011-11-01Merge branches 'for-32/i2c/nomadik', 'for-32/i2c/s3c2410-dt' and ↵Ben Dooks
'for-32/i2c/tegra-iomem' into for-linus/i2c-3.2
2011-10-29i2c-s3c2410: Add device tree supportThomas Abraham
Add device tree probe support for Samsung's s3c2410 i2c driver. Cc: Ben Dooks <ben-linux@fluff.org> Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org> Acked-by: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Ben Dooks <ben-linux@fluff.org>
2011-10-29i2c-s3c2410: Keep a copy of platform data and use itThomas Abraham
The platform data is copied into driver's private data and the copy is used for all access to the platform data. This simpifies the addition of device tree support for the i2c-s3c2410 driver. Cc: Ben Dooks <ben-linux@fluff.org> Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org> Acked-by: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Ben Dooks <ben-linux@fluff.org>