kernel/linux.git/drivers/i2c, branch linux-4.20.y

i2c: omap: Use noirq system sleep pm ops to idle device for suspend

2019-03-13T21:04:16+00:00

[ Upstream commit c6e2bd956936d925748581e4d0294f10f1d92f2c ] We currently get the following error with pixcir_ts driver during a suspend resume cycle: omap_i2c 4802a000.i2c: controller timed out pixcir_ts 1-005c: pixcir_int_enable: can't read reg 0x34 : -110 pixcir_ts 1-005c: Failed to disable interrupt generation: -110 pixcir_ts 1-005c: Failed to stop dpm_run_callback(): pixcir_i2c_ts_resume+0x0/0x98 [pixcir_i2c_ts] returns -110 PM: Device 1-005c failed to resume: error -110 And at least am437x based devices with pixcir_ts will fail to resume to a touchscreen that is configured as the wakeup-source in device tree for these devices. This is because pixcir_ts tries to reconfigure it's registers for noirq suspend which fails. This also leaves i2c-omap in enabled state for suspend. Let's fix the pixcir_ts issue and make sure i2c-omap is suspended by adding SET_NOIRQ_SYSTEM_SLEEP_PM_OPS. Let's also get rid of some ifdefs while at it and replace them with __maybe_unused as SET_RUNTIME_PM_OPS and SET_NOIRQ_SYSTEM_SLEEP_PM_OPS already deal with the various PM Kconfig options. Reported-by: Keerthy Signed-off-by: Tony Lindgren Acked-by: Vignesh R Signed-off-by: Wolfram Sang Signed-off-by: Sasha Levin

i2c: sh_mobile: Add support for r8a774c0 (RZ/G2E)

2019-02-12T19:02:21+00:00

[ Upstream commit 51243b73455f2d12cb82abffa7bc9028aec656e0 ] Similarly to R-Car E3, RZ/G2E doesn't come with automatic transmission registers, as such it is not considered compatible with the existing fallback bindings. Add SoC specific binding compatibility to allow for later support for automatic transmission. Signed-off-by: Fabrizio Castro Reviewed-by: Geert Uytterhoeven Reviewed-by: Simon Horman Signed-off-by: Wolfram Sang Signed-off-by: Sasha Levin

i2c-axxia: check for error conditions first

2019-02-12T19:02:18+00:00

[ Upstream commit 4f5c85fe3a60ace555d09898166af372547f97fc ] It was observed that when using seqentional mode contrary to the documentation, the SS bit (which is supposed to only be set if automatic/sequence command completed normally), is sometimes set together with NA (NAK in address phase) causing transfer to falsely be considered successful. My assumption is that this does not happen during manual mode since the controller is stopping its work the moment it sets NA/ND bit in status register. This is not the case in Automatic/Sequentional mode where it is still working to send STOP condition and the actual status we get depends on the time when the ISR is run. This patch changes the order of checking status bits in ISR - error conditions are checked first and only if none of them occurred, the transfer may be considered successful. This is required to introduce using of sequentional mode in next patch. Signed-off-by: Krzysztof Adamski Reviewed-by: Alexander Sverdlin Signed-off-by: Wolfram Sang Signed-off-by: Sasha Levin

i2c: sh_mobile: add support for r8a77990 (R-Car E3)

2019-02-12T19:02:11+00:00

[ Upstream commit 5eb316e636eb298c204f5b368526d4480b63c0ba ] Add support for the IIC code for the r8a77990 (R-Car E3). It is not considered compatible with existing fallback bindings due to the documented absence of automatic transmission registers. These registers are currently not used by the driver and thus the provides the same behaviour for "renesas,iic-r8a77990" and "renesas,rcar-gen3-iic". The point of declaring incompatibility is to allow for automatic transmission register support to be added to "renesas,iic-r8a77990" and "renesas,rcar-gen3-iic" in future. Signed-off-by: Simon Horman Reviewed-by: Geert Uytterhoeven Signed-off-by: Wolfram Sang Signed-off-by: Sasha Levin

i2c: dev: prevent adapter retries and timeout being set as minus value

2019-01-16T21:03:24+00:00

commit 6ebec961d59bccf65d08b13fc1ad4e6272a89338 upstream. If adapter->retries is set to a minus value from user space via ioctl, it will make __i2c_transfer and __i2c_smbus_xfer skip the calling to adapter->algo->master_xfer and adapter->algo->smbus_xfer that is registered by the underlying bus drivers, and return value 0 to all the callers. The bus driver will never be accessed anymore by all users, besides, the users may still get successful return value without any error or information log print out. If adapter->timeout is set to minus value from user space via ioctl, it will make the retrying loop in __i2c_transfer and __i2c_smbus_xfer always break after the the first try, due to the time_after always returns true. Signed-off-by: Yi Zeng [wsa: minor grammar updates to commit message] Signed-off-by: Wolfram Sang Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman

i2c: nvidia-gpu: mark resume function as __maybe_unused

2018-12-11T20:39:43+00:00

When CONFIG_PM is disabled, this is needed to avoid a harmless unused-function warning: drivers/i2c/busses/i2c-nvidia-gpu.c:345:12: error: 'gpu_i2c_resume' defined but not used [-Werror=unused-function] Fixes: c71bcdcb42a7 ("i2c: add i2c bus driver for NVIDIA GPU") Signed-off-by: Arnd Bergmann Reviewed-by: Andy Shevchenko Signed-off-by: Wolfram Sang

i2c: uniphier-f: fix violation of tLOW requirement for Fast-mode

2018-12-06T22:14:59+00:00

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 Signed-off-by: Wolfram Sang

i2c: uniphier: fix violation of tLOW requirement for Fast-mode

2018-12-06T22:14:59+00:00

i2c: uniphier-f: fill TX-FIFO only in IRQ handler for repeated START

2018-12-06T22:14:59+00:00

- 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 Signed-off-by: Wolfram Sang

i2c: uniphier-f: fix timeout error after reading 8 bytes

2018-12-06T22:14:59+00:00

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 Signed-off-by: Wolfram Sang