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2020-04-19i2c: busses: remove duplicate dev_err()Dejin Zheng1-3/+1
it will print an error message by itself when platform_get_irq() goes wrong. so don't need dev_err() in here again. Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Suggested-by: Markus Elfring <Markus.Elfring@web.de> Signed-off-by: Dejin Zheng <zhengdejin5@gmail.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2020-03-25i2c: drivers: Use generic definitions for bus frequenciesAndy Shevchenko1-4/+2
Since we have generic definitions for bus frequencies, let's use them. Reviewed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> Acked-by: Robert Richter <rrichter@marvell.com> Reviewed-by: Thor Thayer <thor.thayer@linux.intel.com> Acked-by: Elie Morisse <syniurge@gmail.com> Acked-by: Nehal Shah <nehal-bakulchandra.shah@amd.com> Reviewed-by: Brendan Higgins <brendanhiggins@google.com> Acked-by: Scott Branden <scott.branden@broadcom.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Acked-by: Baruch Siach <baruch@tkos.co.il> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Acked-by: Oleksij Rempel <o.rempel@pengutronix.de> Acked-by: Vladimir Zapolskiy <vz@mleia.com> Acked-by: Gregory CLEMENT <gregory.clement@bootlin.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> Reviewed-by: Chris Brandt <chris.brandt@renesas.com> Reviewed-by: Baolin Wang <baolin.wang7@gmail.com> Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com> Acked-by: Patrice Chotard <patrice.chotard@st.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Dmitry Osipenko <digetx@gmail.com> Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2019-09-05i2c: uniphier(-f): remove all dev_dbg()Masahiro Yamada1-21/+1
I have fixed various bugs, and these drivers are (I hope) pretty stable now. Remove all dev_dbg() for code clean-up. If I end up with debugging the drivers again, I will locally revert this commit. I no longer need the debug code in upstream. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2019-09-05i2c: uniphier(-f): use devm_platform_ioremap_resource()Masahiro Yamada1-3/+1
Replace the chain of platform_get_resource() and devm_ioremap_resource() with devm_platform_ioremap_resource(). This allows to remove the local variable for (struct resource *), and have one function call less. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157Thomas Gleixner1-10/+1
Based on 3 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version [author] [kishon] [vijay] [abraham] [i] [kishon]@[ti] [com] this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version [author] [graeme] [gregory] [gg]@[slimlogic] [co] [uk] [author] [kishon] [vijay] [abraham] [i] [kishon]@[ti] [com] [based] [on] [twl6030]_[usb] [c] [author] [hema] [hk] [hemahk]@[ti] [com] this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1105 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.202006027@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-07i2c: uniphier-f: fix violation of tLOW requirement for Fast-modeMasahiro Yamada1-1/+18
Currently, the clock duty is set as tLOW/tHIGH = 1/1. For Fast-mode, tLOW is set to 1.25 us while the I2C spec requires tLOW >= 1.3 us. tLOW/tHIGH = 5/4 would meet both Standard-mode and Fast-mode: Standard-mode: tLOW = 5.56 us, tHIGH = 4.44 us Fast-mode: tLOW = 1.39 us, tHIGH = 1.11 us Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-12-07i2c: uniphier-f: fill TX-FIFO only in IRQ handler for repeated STARTMasahiro Yamada1-4/+9
- For a repeated START condition, this controller starts data transfer immediately after the slave address is written to the TX-FIFO. - Once the TX-FIFO empty interrupt is asserted, the controller makes a pause even if additional data are written to the TX-FIFO. Given those circumstances, the data after a repeated START may not be transferred if the interrupt is asserted while the TX-FIFO is being filled up. A more reliable way is to append TX data only in the interrupt handler. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-12-07i2c: uniphier-f: fix timeout error after reading 8 bytesMasahiro Yamada1-3/+14
I was totally screwed up in commit eaba68785c2d ("i2c: uniphier-f: fix race condition when IRQ is cleared"). Since that commit, if the number of read bytes is multiple of the FIFO size (8, 16, 24... bytes), the STOP condition could be issued twice, depending on the timing. If this happens, the controller will go wrong, resulting in the timeout error. It was more than 3 years ago when I wrote this driver, so my memory about this hardware was vague. Please let me correct the description in the commit log of eaba68785c2d. Clearing the IRQ status on exiting the IRQ handler is absolutely fine. This controller makes a pause while any IRQ status is asserted. If the IRQ status is cleared first, the hardware may start the next transaction before the IRQ handler finishes what it supposed to do. This partially reverts the bad commit with clear comments so that I will never repeat this mistake. I also investigated what is happening at the last moment of the read mode. The UNIPHIER_FI2C_INT_RF interrupt is asserted a bit earlier (by half a period of the clock cycle) than UNIPHIER_FI2C_INT_RB. I consulted a hardware engineer, and I got the following information: UNIPHIER_FI2C_INT_RF asserted at the falling edge of SCL at the 8th bit. UNIPHIER_FI2C_INT_RB asserted at the rising edge of SCL at the 9th (ACK) bit. In order to avoid calling uniphier_fi2c_stop() twice, check the latter interrupt. I also commented this because it is obscure hardware internal. Fixes: eaba68785c2d ("i2c: uniphier-f: fix race condition when IRQ is cleared") Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-10-29i2c: uniphier-f: fix race condition when IRQ is clearedMasahiro Yamada1-5/+6
The current IRQ handler clears all the IRQ status bits when it bails out. This is dangerous because it might clear away the status bits that have just been set while processing the current handler. If this happens, the IRQ event for the latest transfer is lost forever. The IRQ status bits must be cleared *before* the next transfer is kicked. Fixes: 6a62974b667f ("i2c: uniphier_f: add UniPhier FIFO-builtin I2C driver") Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-10-29i2c: uniphier-f: fix occasional timeout errorMasahiro Yamada1-8/+25
Currently, a timeout error could happen at a repeated START condition. For a (non-repeated) START condition, the controller starts sending data when the UNIPHIER_FI2C_CR_STA bit is set. However, for a repeated START condition, the hardware starts running when the slave address is written to the TX FIFO - the write to the UNIPHIER_FI2C_CR register is actually unneeded. Because the hardware is already running before the IRQ is enabled for a repeated START, the driver may miss the IRQ event. In most cases, this problem does not show up since modern CPUs are much faster than the I2C transfer. However, it is still possible that a context switch happens after the controller starts, but before the IRQ register is set up. To fix this, - Do not write UNIPHIER_FI2C_CR for repeated START conditions. - Enable IRQ *before* writing the slave address to the TX FIFO. - Disable IRQ for the current CPU while queuing up the TX FIFO; If the CPU is interrupted by some task, the interrupt handler might be invoked due to the empty TX FIFO before completing the setup. Fixes: 6a62974b667f ("i2c: uniphier_f: add UniPhier FIFO-builtin I2C driver") Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-10-29i2c: uniphier-f: make driver robust against concurrencyMasahiro Yamada1-1/+16
This is unlikely to happen, but it is possible for a CPU to enter the interrupt handler just after wait_for_completion_timeout() has expired. If this happens, the hardware is accessed from multiple contexts concurrently. Disable the IRQ after wait_for_completion_timeout(), and do nothing from the handler when the IRQ is disabled. Fixes: 6a62974b667f ("i2c: uniphier_f: add UniPhier FIFO-builtin I2C driver") Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-09-03i2c: uniphier-f: issue STOP only for last message or I2C_M_STOPMasahiro Yamada1-5/+2
This driver currently emits a STOP if the next message is not I2C_MD_RD. It should not do it because it disturbs the I2C_RDWR ioctl, where read/write transactions are combined without STOP between. Issue STOP only when the message is the last one _or_ flagged with I2C_M_STOP. Fixes: 6a62974b667f ("i2c: uniphier_f: add UniPhier FIFO-builtin I2C driver") Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-08-12i2c: uniphier-f: add suspend / resume supportMasahiro Yamada1-9/+37
When resuming, set up registers that have been lost in the sleep state. Also, add clock handling in the resume / suspend hooks. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-11-18i2c: uniphier-f: rename jump label to follow coding style guidelineMasahiro Yamada1-3/+3
Documentation/CodingStyle recommends to use label names which say what the goto does or why the goto exists. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-09-24i2c: uniphier-f: fix misdetection of incomplete STOP conditionMasahiro Yamada1-5/+11
Currently, the status register FI2C_SR is checked immediately after a STOP condition is issued in case of the deferred STOP condition. It takes typically 5-10 usec until the corresponding bits in the register are set, so the error check for "stop condition was not completed" is very likely to be false positive. Add wait code to relax the status register check. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-09-08i2c: uniphier-f: set the adapter to master mode when probingMasahiro Yamada1-6/+10
Currently, the adapter is set to the master mode at the first use. Since then, it is kept in the slave mode, so unexpected glitch signals on the I2C lines may cause the adapter into insane state. Setting it to the master mode along with initialization solves the problem. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Reported-by: Akio Noda <noda.akio@socionext.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-09-08i2c: uniphier-f: avoid WARN_ON() of clk_disable() in failure pathMasahiro Yamada1-41/+32
If clk_prepare_enable() fails, clk_disable_unprepare() is called in the failure path, where the enable_count is still zero, so it hits WARN_ON(core->enable_count == 0) in the clk_core_disable(). To fix this, make the clock setting more linear in the probe function so that it can exploit "goto err" in case of error. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-08-22i2c: uniphier{-f}: don't print error when adding adapter failsWolfram Sang1-5/+0
The core will do this for us now. Signed-off-by: Wolfram Sang <wsa-dev@sang-engineering.com> Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-04-27i2c: uniphier: add "\n" at the end of error logMasahiro Yamada1-1/+1
Just in case. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-02-12i2c: uniphier: fix typos in error messagesMasahiro Yamada1-1/+1
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-12-14i2c: uniphier_f: error out if bus speed is zeroMasahiro Yamada1-0/+5
There is code to divide by "bus_speed" some lines below. To eliminate the possibility of division by zero, bail out if "clock-frequency" is specified as zero. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-12-14i2c: uniphier_f: error out if clock rate is zeroMasahiro Yamada1-1/+5
This input clock is used to generate the sampling clock for I2C bus. If the clock rate is zero, there is something wrong with the clock driver. Bail out with the appropriate error message in such a case. It would make it easier to find the root cause of failure. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-10-23i2c: uniphier_f: add UniPhier FIFO-builtin I2C driverMasahiro Yamada1-0/+584
Add support for on-chip I2C controller used on newer UniPhier SoCs such as PH1-Pro4, PH1-Pro5, etc. This adapter is equipped with 8-depth TX/RX FIFOs. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>