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2017-10-28i2c: img-scb: Add runtime PMEd Blake1-19/+78
The i2c-img-scb driver already dynamically enables / disables clocks to save power, but doesn't use the runtime PM framework. Convert the driver to use runtime PM, so that dynamic clock management will be disabled when runtime PM is disabled, and so that autosuspend can be used to avoid unnecessarily disabling and re-enabling clocks repeatedly during a sequence of transactions. Signed-off-by: Ed Blake <ed.blake@sondrel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-10-27i2c/busses: Convert timers to use timer_setup()Kees Cook1-4/+3
In preparation for unconditionally passing the struct timer_list pointer to all timer callbacks, switch to using the new timer_setup() and from_timer() to pass the timer pointer explicitly. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-10-04Update James Hogan's email addressJames Hogan1-1/+1
Update my imgtec.com and personal email address to my kernel.org one in a few places as MIPS will soon no longer be part of Imagination Technologies, and add mappings in .mailcap so get_maintainer.pl reports the right address. Signed-off-by: James Hogan <jhogan@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-04-16i2c: img-scb: use setup_timerGeliang Tang1-3/+2
Use setup_timer() instead of init_timer() to simplify the code. Signed-off-by: Geliang Tang <geliangtang@gmail.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-08-22i2c: don't print error when adding adapter failsWolfram Sang1-3/+1
The core will do this for us now. Signed-off-by: Wolfram Sang <wsa-dev@sang-engineering.com> Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com> Acked-by: Peter Korsgaard <peter@korsgaard.com> Acked-by: Heiko Stuebner <heiko@sntech.de> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Thierry Reding <treding@nvidia.com> Acked-by: Ray Jui <ray.jui@broadcom.com> Acked-by: Vladimir Zapolskiy <vz@mleia.com> Acked-by: Ludovic Desroches <ludovic.desroches@atmel.com> Acked-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Acked-by: Laxman Dewangan <ldewangan@nvidia.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-04-11i2c: img-scb: use new 8 bit address helper functionWolfram Sang1-3/+1
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-01-02i2c: img-scb: support repeated starts on IP v3.3Sifan Naeem1-9/+36
In version 3.3 of the IP when transaction halt is set, an interrupt will be generated after each byte of a transfer instead of after every transfer but before the stop bit. Due to this behaviour we have to be careful that every time we release the transaction halt we have to re-enable it straight away so that we only process a single byte, not doing so will result in all remaining bytes been processed and a stop bit being issued, which will prevent us having a repeated start. This change will have no effect on earlier versions of the IP. Signed-off-by: Sifan Naeem <sifan.naeem@imgtec.com> Acked-by: James Hogan <james.hogan@imgtec.com> Reviewed-by: James Hartley <james.hartley@imgtec.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-01-02i2c: img-scb: add handle for Master halt interruptSifan Naeem1-3/+14
Master halt is issued after each byte of a transaction is processed in IP version 3.3. Master halt will stall the bus by holding the SCK line low until the halt bit in the scb_general_control is cleared. After the last byte of a transfer is processed we can use the Master Halt interrupt to facilitate a repeated start transfer without issuing a stop bit. Signed-off-by: Sifan Naeem <sifan.naeem@imgtec.com> Reviewed-by: James Hartley <james.hartley@imgtec.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-01-02i2c: img-scb: add handle for stop detected interruptSifan Naeem1-1/+10
Stop Detected interrupt is triggered when a Stop bit is detected on the bus, which indicates the end of the current transfer. When the end of a transfer is indicated by the Stop Detected interrupt, drain the FIFO and signal completion for the transaction. Signed-off-by: Sifan Naeem <sifan.naeem@imgtec.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-01-02i2c: img-scb: remove fifo EMPTYING interrupts handleSifan Naeem1-13/+3
Now that we are using the transaction halt interrupt to safely control repeated start transfers, we no longer need to handle the fifo emptying interrupts. Handling this interrupt along with Transaction Halt interrupt can cause erratic behaviour. Signed-off-by: Sifan Naeem <sifan.naeem@imgtec.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2016-01-02i2c: img-scb: support I2C_M_IGNORE_NAKSifan Naeem1-5/+10
This commit adds support for the I2C_M_IGNORE_NAK protocol modification. Such behaviour can only be implemented in atomic mode. So, if a transaction contains a message with such flag the drivers switches to atomic mode. The implementation consists simply in treating NAKs as ACKs. Signed-off-by: Sifan Naeem <sifan.naeem@imgtec.com> Acked-by: James Hogan <james.hogan@imgtec.com> Reviewed-by: James Hartley <james.hartley@imgtec.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-10-10i2c: img-scb: verify support for requested bit rateSifan Naeem1-3/+11
The requested bit rate can be outside the range supported by the driver. The maximum bit rate this driver supports at the moment is 400Khz. If the requested bit rate is larger than the maximum supported by the driver, set the bitrate to the maximum supported before bitrate_khz is calculated. Maximum speed supported by the driver can be increased to 1Mhz by adding support for "fast plus mode" in the future. Fixes: commit 27bce457d588 ("i2c: img-scb: Add Imagination Technologies I2C SCB driver") Signed-off-by: Sifan Naeem <sifan.naeem@imgtec.com> Acked-by: James Hogan <james.hogan@imgtec.com> Reviewed-by: James Hartley <james.hartley@imgtec.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-10-10i2c: img-scb: Clear line and interrupt status before starting a transferSifan Naeem1-0/+9
Clear line status and all generated interrupts from the interrupt status register before starting a transfer, as we may have unserviced interrupts from previous transfers that might be handled in the context of the new transfer. Fixes: commit 27bce457d588 ("i2c: img-scb: Add Imagination Technologies I2C SCB driver") Signed-off-by: Sifan Naeem <sifan.naeem@imgtec.com> Acked-by: James Hogan <james.hogan@imgtec.com> Reviewed-by: James Hartley <james.hartley@imgtec.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-10-10i2c: img-scb: use line_status instead of i2c->line_statusSifan Naeem1-1/+1
i2c->line_status accumulates the line status bits that have been seen with each interrupt. As we're only interested in that bit from the current interrupt, refer to line_status (the argument to img_i2c_auto) instead of i2c->line_status. Signed-off-by: Sifan Naeem <sifan.naeem@imgtec.com> Reviewed-by: James Hartley <james.hartley@imgtec.com> Acked-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-10-10i2c: img-scb: fix LOW and HIGH period values for the SCL clockSifan Naeem1-13/+17
Currently, after determining the minimum value for the High period (TCKH) the remainder of the internal clock pulses is set as the Low period (TCKL). This causes the i2c clock duty cycle to be much less than 50%. Modify the starting position to TCKH and TCKL at 50% of the internal clock, and adjusts the TCKH and TCKL values from there should the minimum value for TCKL not be met. This results in duty cycles closer to 50%. Fixes: commit 27bce457d588 ("i2c: img-scb: Add Imagination Technologies I2C SCB driver") Signed-off-by: Sifan Naeem <sifan.naeem@imgtec.com> Acked-by: James Hogan <james.hogan@imgtec.com> Reviewed-by: James Hartley <james.hartley@imgtec.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-10-10i2c: img-scb: use DIV_ROUND_UP to round divisor valuesSifan Naeem1-6/+2
Using % can be slow depending on the architecture. Using DIV_ROUND_UP is nicer and more efficient way to do it. Fixes: commit 27bce457d588 ("i2c: img-scb: Add Imagination Technologies I2C SCB driver") Signed-off-by: Sifan Naeem <sifan.naeem@imgtec.com> Acked-by: James Hogan <james.hogan@imgtec.com> Reviewed-by: James Hartley <james.hartley@imgtec.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-10-10i2c: img-scb: do dummy writes before fifo accessSifan Naeem1-2/+2
Move scb_wr_rd_fence to before reading from fifo and writing to fifo to make sure the the first read/write is done after the required number of cycles. Fixes: commit 27bce457d588 ("i2c: img-scb: Add Imagination Technologies I2C SCB driver") Signed-off-by: Sifan Naeem <sifan.naeem@imgtec.com> Acked-by: James Hogan <james.hogan@imgtec.com> Reviewed-by: James Hartley <james.hartley@imgtec.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-10-10i2c: img-scb: enable fencing for all versions of the ipSifan Naeem1-6/+2
The code to read from the master read fifo, and write to the master write fifo, checks a bit in an SCB register before every byte to ensure that the fifo is not full (write fifo) or empty (read fifo). Due to clock domain crossing inside the SCB block the updated value of this bit is only visible after 2 cycles. The scb_wr_rd_fence() function does 2 dummy writes (to the read-only revision register), and it's called before reading from or writing to the fifos to ensure that subsequent reads of the fifo status bits do not read stale values. As the 2 dummy writes are required in all versions of the ip, the version check is dropped. Fixes: commit 27bce457d588 ("i2c: img-scb: Add Imagination Technologies I2C SCB driver") Signed-off-by: Sifan Naeem <sifan.naeem@imgtec.com> Acked-by: James Hogan <james.hogan@imgtec.com> Reviewed-by: James Hartley <james.hartley@imgtec.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2015-03-15i2c: img-scb: fixup of wait_for_completion_timeout return handlingNicholas Mc Guire1-6/+8
Return type of wait_for_completion_timeout is unsigned long not int. Appropriately typed/named variable are added and assignment fixed up. Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org> Acked-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-11-17i2c: img-scb: Add Imagination Technologies I2C SCB driverJames Hogan1-0/+1412
Add support for the IMG I2C Serial Control Bus (SCB) found on the Pistachio and TZ1090 SoCs. Reviewed-by: Andrew Bresticker <abrestic@chromium.org> Signed-off-by: James Hogan <james.hogan@imgtec.com> [Ezequiel: code cleaning and rebasing] Signed-off-by: Ezequiel Garcia <ezequiel.garcia@imgtec.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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