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path: root/drivers/i2c/busses/i2c-img-scb.c
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2016-08-22i2c: don't print error when adding adapter failsWolfram Sang
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 Sang
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 Naeem
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 Naeem
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 Naeem
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 Naeem
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 Naeem
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 Naeem
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 Naeem
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 Naeem
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 Naeem
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 Naeem
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 Naeem
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 Naeem
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 Guire
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 Hogan
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>