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* i2c: bcm2835: reword according to newest specificationWolfram Sang2024-07-111-5/+5
| | | | | | | | | | Change the wording of this driver wrt. the newest I2C v7 and SMBus 3.2 specifications and replace "master/slave" with more appropriate terms. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com> Reviewed-by: Andi Shyti <andi.shyti@kernel.org> Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
* i2c: bcm2835: remove printout on handled timeoutsWolfram Sang2024-05-061-1/+0
| | | | | | | | | | I2C and SMBus timeouts are not something the user needs to be informed about on controller level. The client driver may know if that really is a problem and give more detailed information to the user. The controller should just pass this information upwards. Remove the printout. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
* I2C: Explicitly include correct DT includesRob Herring2023-08-141-1/+1
| | | | | | | | | | | | | | | The DT of_device.h and of_platform.h date back to the separate of_platform_bus_type before it as merged into the regular platform bus. As part of that merge prepping Arm DT support 13 years ago, they "temporarily" include each other. They also include platform_device.h and of.h. As a result, there's a pretty much random mix of those include files used throughout the tree. In order to detangle these headers and replace the implicit includes with struct declarations, users need to explicitly include the correct includes. Signed-off-by: Rob Herring <robh@kernel.org> Reviewed-by: Andi Shyti <andi.shyti@kernel.org> Signed-off-by: Wolfram Sang <wsa@kernel.org>
* i2c: bcm2835: Use dev_err_probe in probe functionLiao Chang2023-08-101-8/+6
| | | | | | | | | | | Use the dev_err_probe function instead of dev_err in the probe function so that the printed message includes the return value and also handles -EPROBE_DEFER nicely. Signed-off-by: Liao Chang <liaochang1@huawei.com> Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com> Link: https://lore.kernel.org/r/20230808012954.1643834-2-liaochang1@huawei.com Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
* i2c: Convert to platform remove callback returning voidUwe Kleine-König2023-06-051-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The .remove() callback for a platform driver returns an int which makes many driver authors wrongly assume it's possible to do error handling by returning an error code. However the value returned is (mostly) ignored and this typically results in resource leaks. To improve here there is a quest to make the remove callback return void. In the first step of this quest all drivers are converted to .remove_new() which already returns void. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Alain Volmat <alain.volmat@foss.st.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Baruch Siach <baruch@tkos.co.il> Acked-by: Florian Fainelli <f.fainelli@gmail.com> Acked-by: Heiko Stuebner <heiko@sntech.de> Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com> Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com> Acked-by: Jochen Friedrich <jochen@scram.de> Acked-by: Peter Rosin <peda@axentia.se> Acked-by: Vadim Pasternak <vadimp@nvidia.com> Reviewed-by: Asmaa Mnebhi <asnaa@nvidia.com> Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> Reviewed-by: Chris Packham <chris.packham@alliedtelesis.co.nz> Reviewed-by: Chris Pringle <chris.pringle@phabrix.com> Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Hans de Goede <hdegoede@redhat.com> Reviewed-by: Jean Delvare <jdelvare@suse.de> Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com> Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com> Reviewed-by: Tali Perry <tali.perry@nuvoton.com> Reviewed-by: Vignesh Raghavendra <vigneshr@ti.com> Signed-off-by: Wolfram Sang <wsa@kernel.org>
* i2c: bcm2835: Use devm_platform_get_and_ioremap_resource()ye xingchen2023-01-201-3/+1
| | | | | | | | | | Convert platform_get_resource(), devm_ioremap_resource() to a single call to devm_platform_get_and_ioremap_resource(), as this is exactly what this function does. Signed-off-by: ye xingchen <ye.xingchen@zte.com.cn> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Wolfram Sang <wsa@kernel.org>
* Merge tag 'irq-api-2022-02-21' of ↵Wolfram Sang2022-02-231-0/+11
|\ | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into i2c/for-mergewindow Provide a tag for maintainers to pull the generic_handle_irq_safe() API.
| * i2c: bcm2835: Avoid clock stretching timeoutsEric Anholt2022-02-071-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | The CLKT register contains at poweron 0x40, which at our typical 100kHz bus rate means .64ms. But there is no specified limit to how long devices should be able to stretch the clocks, so just disable the timeout. We still have a timeout wrapping the entire transfer. Signed-off-by: Eric Anholt <eric@anholt.net> Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com> BugLink: https://github.com/raspberrypi/linux/issues/3064 Signed-off-by: Wolfram Sang <wsa@kernel.org>
* | i2c: bcm2835: Fix the error handling in 'bcm2835_i2c_probe()'Christophe JAILLET2022-02-071-5/+16
|/ | | | | | | | | | | | | | | | Some resource should be released if an error occurs in 'bcm2835_i2c_probe()'. Add an error handling path and the needed 'clk_disable_unprepare()' and 'clk_rate_exclusive_put()' calls. While at it, rework the bottom of the function to use this newly added error handling path and have an explicit and more standard "return 0;" at the end of the normal path. Fixes: bebff81fb8b9 ("i2c: bcm2835: Model Divider in CCF") Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> [wsa: rebased] Signed-off-by: Wolfram Sang <wsa@kernel.org>
* i2c: bcm2835: Use platform_get_irq() to get the interruptLad Prabhakar2022-01-031-7/+4
| | | | | | | | | | | | | | | platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static allocation of IRQ resources in DT core code, this causes an issue when using hierarchical interrupt domains using "interrupts" property in the node as this bypasses the hierarchical setup and messes up the irq chaining. In preparation for removal of static setup of IRQ resource from DT core code use platform_get_irq(). Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Wolfram Sang <wsa@kernel.org>
* i2c: bcm2835: Simplify with dev_err_probe()Krzysztof Kozlowski2020-09-181-5/+3
| | | | | | | | | Common pattern of handling deferred probe can be simplified with dev_err_probe(). Less code and the error value gets printed. Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Acked-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Wolfram Sang <wsa@kernel.org>
* i2c: bcm2835: Replace HTTP links with HTTPS onesAlexander A. Klimov2020-08-051-1/+1
| | | | | | | | | | Rationale: Reduces attack surface on kernel devs opening the links for MITM as HTTPS traffic is much harder to manipulate. Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de> [wsa: shortened commit message] Signed-off-by: Wolfram Sang <wsa@kernel.org>
* i2c: drivers: Use generic definitions for bus frequenciesAndy Shevchenko2020-03-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* i2c: bcm2835: Store pointer to bus clockStefan Wahren2020-01-061-9/+8
| | | | | | | | | | | The commit bebff81fb8b9 ("i2c: bcm2835: Model Divider in CCF") introduced a NULL pointer dereference on driver unload. It seems that we can't fetch the bus clock via devm_clk_get in bcm2835_i2c_remove. As an alternative approach store a pointer to the bus clock in the private driver structure. Fixes: bebff81fb8b9 ("i2c: bcm2835: Model Divider in CCF") Signed-off-by: Stefan Wahren <wahrenst@gmx.net> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* i2c: bcm2835: Add full name of devicetree node to adapter nameStefan Wahren2019-08-291-1/+2
| | | | | | | | | | Inspired by Lori Hikichi's patch for iproc, this adds the full name of the devicetree node to the adapter name. With the introduction of BCM2711 it's very difficult to distinguish between the multiple instances. Signed-off-by: Stefan Wahren <wahrenst@gmx.net> Acked-by: Scott Branden <scott.branden@broadcom.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* i2c: bcm2835: Avoid clk stretch quirk for BCM2711Stefan Wahren2019-08-291-3/+5
| | | | | | | | | The I2C block on the BCM2711 isn't affected by the clk stretching bug. So there is no need to apply the corresponding quirk. Signed-off-by: Stefan Wahren <wahrenst@gmx.net> Reviewed-by: Eric Anholt <eric@anholt.net> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* i2c: bcm2835: Ensure clock exists when probingAnnaliese McDermond2019-06-261-4/+12
| | | | | | | | | | | | | | | Probe function fails to recognize that upstream clock actually doesn't yet exist because clock driver has not been initialized. Actually try to go get the clock and test for its existence before trying to set up a downstream clock based upon it. This fixes a bug that causes the i2c driver not to work with monolithic kernels. Fixes: bebff81fb8b9 ("i2c: bcm2835: Model Divider in CCF") Signed-off-by: Annaliese McDermond <nh6z@nh6z.net> Acked-by: Stefan Wahren <wahrenst@gmx.net> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* i2c: bcm2835: Move IRQ request after clock code in probeAnnaliese McDermond2019-06-261-14/+14
| | | | | | | | | | | | | If any of the clock code in the probe fails and returns, the IRQ will not be freed. Moving the IRQ request to last allows it to be freed on any errors further up in the probe function. devm_ calls can apparently not be used because there are some potential race conditions that will arise. Fixes: bebff81fb8b9 ("i2c: bcm2835: Model Divider in CCF") Signed-off-by: Annaliese McDermond <nh6z@nh6z.net> Acked-by: Stefan Wahren <wahrenst@gmx.net> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* i2c: bcm2835: Model Divider in CCFAnnaliese McDermond2019-06-121-31/+114
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Model the I2C bus clock divider as a part of the Core Clock Framework. Primarily this removes the clk_get_rate() call from each transfer. This call causes problems for slave drivers that themselves have internal clock components that are controlled by an I2C interface. When the slave's internal clock component is prepared, the prepare lock is obtained, and it makes calls to the I2C subsystem to command the hardware to activate the clock. In order to perform the I2C transfer, this driver sets the divider, which requires it to get the parent clock rate, which it does with clk_get_rate(). Unfortunately, this function will try to take the clock prepare lock, which is already held by the slave's internal clock calls creating a deadlock. Modeling the divider in the CCF natively removes this dependency and the divider value is only set upon changing the bus clock frequency or changes in the parent clock that cascade down to this divisor. This obviates the need to set the divider with every transfer and avoids the deadlock described above. It also should provide better clock debugging and save a few cycles on each transfer due to not having to recalcuate the divider value. Signed-off-by: Annaliese McDermond <nh6z@nh6z.net> Acked-by: Stefan Wahren <stefan.wahren@i2se.com> Reviewed-by: Eric Anholt <eric@anholt.net> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* i2c: bcm2835: Clear current buffer pointers and counts after a transferPaul Kocialkowski2019-02-151-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | The driver's interrupt handler checks whether a message is currently being handled with the curr_msg pointer. When it is NULL, the interrupt is considered to be unexpected. Similarly, the i2c_start_transfer routine checks for the remaining number of messages to handle in num_msgs. However, these values are never cleared and always keep the message and number relevant to the latest transfer (which might be done already and the underlying message memory might have been freed). When an unexpected interrupt hits with the DONE bit set, the isr will then try to access the flags field of the curr_msg structure, leading to a fatal page fault. The msg_buf and msg_buf_remaining fields are also never cleared at the end of the transfer, which can lead to similar pitfalls. Fix these issues by introducing a cleanup function and always calling it after a transfer is finished. Fixes: e2474541032d ("i2c: bcm2835: Fix hang for writing messages larger than 16 bytes") Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com> Acked-by: Stefan Wahren <stefan.wahren@i2se.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* i2c: bcm2835: Switch to SPDX identifierStefan Wahren2018-11-271-9/+1
| | | | | | | | | Adopt the SPDX license identifier headers to ease license compliance management. Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com> Reviewed-by: Eric Anholt <eric@anholt.net> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* i2c: bcm2835: Set up the rising/falling edge delaysEric Anholt2018-02-221-1/+20
| | | | | | | | | | | | We were leaving them in the power on state (or the state the firmware had set up for some client, if we were taking over from them). The boot state was 30 core clocks, when we actually want to sample some time after (to make sure that the new input bit has actually arrived). Signed-off-by: Eric Anholt <eric@anholt.net> Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Cc: stable@kernel.org
* i2c: bcm2835: Avoid possible NULL ptr dereferenceStefan Wahren2017-02-201-1/+3
| | | | | | | | | | | | | | | Since commit e2474541032d ("bcm2835: Fix hang for writing messages larger than 16 bytes") the interrupt handler is prone to a possible NULL pointer dereference. This could happen if an interrupt fires before curr_msg is set by bcm2835_i2c_xfer_msg() and randomly occurs on the RPi 3. Even this is an unexpected behavior the driver must handle that with an error instead of a crash. Reported-by: Peter Robinson <pbrobinson@gmail.com> Fixes: e2474541032d ("bcm2835: Fix hang for writing messages larger than 16 bytes") Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com> Acked-by: Noralf Trønnes <noralf@tronnes.org> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* i2c: bcm2835: Add support for dynamic clockNoralf Trønnes2016-11-071-19/+32
| | | | | | | | | Support a dynamic clock by reading the frequency and setting the divisor in the transfer function instead of during probe. Signed-off-by: Noralf Trønnes <noralf@tronnes.org> Reviewed-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* i2c: bcm2835: Support i2c-dev ioctl I2C_TIMEOUTNoralf Trønnes2016-11-071-3/+1
| | | | | | | | | Use i2c_adapter->timeout for the completion timeout value. The core default is 1 second. Signed-off-by: Noralf Trønnes <noralf@tronnes.org> Reviewed-by: Eric Anholt <eric@anholt.net> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* i2c: bcm2835: Add support for Repeated Start ConditionNoralf Trønnes2016-11-071-38/+63
| | | | | | | | | | | | | | | | | | | | | | | | Documentation/i2c/i2c-protocol states that Combined transactions should separate messages with a Start bit and end the whole transaction with a Stop bit. This patch adds support for issuing only a Start between messages instead of a Stop followed by a Start. This implementation differs from downstream i2c-bcm2708 in 2 respects: - it uses an interrupt to detect that the transfer is active instead of using polling. There is no interrupt for Transfer Active, but by not prefilling the FIFO it's possible to use the TXW interrupt. - when resetting/disabling the controller between transfers it writes CLEAR to the control register instead of just zero. Using just zero gave many errors. This might be the reason why downstream had to disable this feature and make it available with a module parameter. I have run thousands of transfers to a DS1307 (rtc), MMA8451 (accel) and AT24C32 (eeprom) in parallel without problems. Signed-off-by: Noralf Trønnes <noralf@tronnes.org> Acked-by: Eric Anholt <eric@anholt.net> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* i2c: bcm2835: Can't support I2C_M_IGNORE_NAKNoralf Trønnes2016-11-071-4/+0
| | | | | | | | | | | | | | | | | | | | | | | The controller can't support this flag, so remove it. Documentation/i2c/i2c-protocol states that all of the message is sent: I2C_M_IGNORE_NAK: Normally message is interrupted immediately if there is [NA] from the client. Setting this flag treats any [NA] as [A], and all of message is sent. >From the BCM2835 ARM Peripherals datasheet: The ERR field is set when the slave fails to acknowledge either its address or a data byte written to it. So when the controller doesn't receive an ack, it sets ERR and raises an interrupt. In other words, the whole message is not sent. Signed-off-by: Noralf Trønnes <noralf@tronnes.org> Reviewed-by: Eric Anholt <eric@anholt.net> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* i2c: bcm2835: Use dev_dbg logging on transfer errorsNoralf Trønnes2016-11-071-1/+1
| | | | | | | | | | | | | Writing to an AT24C32 generates on average 2x i2c transfer errors per 32-byte page write. Which amounts to a lot for a 4k write. This is due to the fact that the chip doesn't respond during it's internal write cycle when the at24 driver tries and retries the next write. Only a handful drivers use dev_err() on transfer error, so switch to dev_dbg() instead. Signed-off-by: Noralf Trønnes <noralf@tronnes.org> Reviewed-by: Eric Anholt <eric@anholt.net> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* i2c: bcm2835: Protect against unexpected TXW/RXR interruptsNoralf Trønnes2016-11-071-9/+31
| | | | | | | | | | | | | | | | | | | | | | If an unexpected TXW or RXR interrupt occurs (msg_buf_remaining == 0), the driver has no way to fill/drain the FIFO to stop the interrupts. In this case the controller has to be disabled and the transfer completed to avoid hang. (CLKT | ERR) and DONE interrupts are completed in their own paths, and the controller is disabled in the transfer function after completion. Unite the code paths and do disabling inside the interrupt routine. Clear interrupt status bits in the united completion path instead of trying to do it on every interrupt which isn't necessary. Only CLKT, ERR and DONE can be cleared that way. Add the status value to the error value in case of TXW/RXR errors to distinguish them from the other S_LEN error. Signed-off-by: Noralf Trønnes <noralf@tronnes.org> Reviewed-by: Eric Anholt <eric@anholt.net> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* i2c: bcm2835: Fix hang for writing messages larger than 16 bytesNoralf Trønnes2016-11-071-8/+14
| | | | | | | | | | | | | | | | | | | | | | | | Writing messages larger than the FIFO size results in a hang, rendering the machine unusable. This is because the RXD status flag is set on the first interrupt which results in bcm2835_drain_rxfifo() stealing bytes from the buffer. The controller continues to trigger interrupts waiting for the missing bytes, but bcm2835_fill_txfifo() has none to give. In this situation wait_for_completion_timeout() apparently is unable to stop the madness. The BCM2835 ARM Peripherals datasheet has this to say about the flags: TXD: is set when the FIFO has space for at least one byte of data. RXD: is set when the FIFO contains at least one byte of data. TXW: is set during a write transfer and the FIFO is less than full. RXR: is set during a read transfer and the FIFO is or more full. Implementing the logic from the downstream i2c-bcm2708 driver solved the hang problem. Signed-off-by: Noralf Trønnes <noralf@tronnes.org> Reviewed-by: Eric Anholt <eric@anholt.net> Reviewed-by: Martin Sperl <kernel@martin.sperl.org> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* i2c: bcm2835: Don't complain on -EPROBE_DEFER from getting our clockEric Anholt2016-07-221-1/+2
| | | | | | | | Fixes dmesg spam when we just need to wait a moment for the clock driver to probe. Signed-off-by: Eric Anholt <eric@anholt.net> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* i2c: bcm2835: add I2C_AQ_NO_CLK_STRETCHNicola Corna2015-11-301-0/+10
| | | | | | | | | | As reported in the links given below. the BCM2835 has a hardware bug in its i2c module which prevents a correct clock stretching. This patch adds the I2C_AQ_NO_CLK_STRETCH quirk flag to i2c-bcm2835. Signed-off-by: Nicola Corna <nicola@corna.info> [wsa: put the links into the code as comments] Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* i2c: busses: i2c-bcm2835: limits cdiv to allowed valuesSilvan Wicki2015-06-231-0/+8
| | | | | | | | | | | | Checks if the cdiv value is in between min (0x2) and max (0xFFFE) supported values by the bcm2835. If not, it returns -ENODEV. See page 33/34 of BCM2835-ARM-Peripherals.pdf for the DIV register. https://www.raspberrypi.org/wp-content/uploads/2012/02/BCM2835-ARM-Peripherals.pdf Signed-off-by: Silvan Wicki <linux_wi@tinag.ch> [wsa: resolved a merge conflict] Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* i2c: bcm2835: clear reserved bits in S-RegisterSilvan Wicki2015-06-171-0/+3
| | | | | | | | | | | | | | The datasheet mentions on page 31 that the bits 10-31 must be read as don't care and written as 0. https://www.raspberrypi.org/wp-content/uploads/2012/02/BCM2835-ARM-Peripherals.pdf We cannot guarantee that we read bits 10-31 as always 0 (because the datasheet says read as don't care). We clear the bits with a bitmask to prevent writing back unknown data at the reserved bits. Signed-off-by: Silvan Wicki <linux_wi@tinag.ch> Acked-by: Stephen Warren <swarren@wwwdotorg.org> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* i2c: i2c-bcm2835: match return type of wait_for_completion_timeoutNicholas Mc Guire2015-03-151-1/+1
| | | | | | | | | | return type of wait_for_completion_timeout is unsigned long not int. as time_left is used for wait_for_completion_timeout exclusively here its type is simply changed to unsigned long. Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org> Acked-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* i2c: busses: drop owner assignment from platform_driversWolfram Sang2014-10-201-1/+0
| | | | | | | A platform_driver does not need to set an owner, it will be populated by the driver core. Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* i2c: i2c-bcm2835: Drop class based scanning to improve bootup timeWolfram Sang2014-07-161-1/+1
| | | | | | | | | | This driver has been flagged to drop class based instantiation. The removal improves boot-up time and is unneeded for embedded controllers. Users have been warned to switch for some time now, so we can actually do the removal. Keep the DEPRECATED flag, so the core can inform users that the behaviour finally changed now. After another transition period, this flag can go, too. Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* i2c: remove unnecessary OOM messagesJingoo Han2014-06-021-3/+1
| | | | | | | | | | | | | | | The site-specific OOM messages are unnecessary, because they duplicate the MM subsystem generic OOM message. For example, k.alloc and v.alloc failures use dump_stack(). Signed-off-by: Jingoo Han <jg1.han@samsung.com> Acked-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Jean Delvare <jdelvare@suse.de> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Felipe Balbi <balbi@ti.com> Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* i2c: i2c-bcm2835: deprecate class based instantiationWolfram Sang2014-03-281-1/+1
| | | | | | | 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>
* i2c: bcm2835: Use devm_ioremap_resource()Jingoo Han2014-03-091-20/+4
| | | | | | | | | | Use devm_ioremap_resource() in order to make the code simpler, and remove redundant return value check of platform_get_resource() because the value is checked by devm_ioremap_resource(). Signed-off-by: Jingoo Han <jg1.han@samsung.com> Acked-by: Stephen Warren <swarren@wwwdotorg.org> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* i2c: bcm2835: Linking platform nodes to adapter nodesFlorian Meier2013-11-281-0/+1
| | | | | | | | | | In order to find I2C devices in the device tree, the platform nodes have to be known by the I2C core. This requires setting the dev.of_node parameter of the adapter. Signed-off-by: Florian Meier <florian.meier@koalo.de> Tested-by: Stephen Warren <swarren@wwwdotorg.org> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
* tree-wide: use reinit_completion instead of INIT_COMPLETIONWolfram Sang2013-11-151-1/+1
| | | | | | | | | | | | 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>
* i2c: add bcm2835 driverStephen Warren2013-02-121-0/+342
This implements a very basic I2C host driver for the BCM2835 SoC. Missing features so far are: * 10-bit addressing. * DMA. Reviewed-by: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Stephen Warren <swarren@wwwdotorg.org> Signed-off-by: Wolfram Sang <wolfram@the-dreams.de>
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