linux/drivers/i2c
Sifan Naeem 0e59378bc0 i2c: img-scb: enable fencing for all versions of the ip
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 27bce457d5 ("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>
2015-10-10 08:37:41 +01:00
..
algos i2c: algo-pca: fix typo in comment 2015-06-01 08:41:19 +09:00
busses i2c: img-scb: enable fencing for all versions of the ip 2015-10-10 08:37:41 +01:00
muxes i2c: mux: reg Change ioread endianness for readback 2015-09-03 11:58:42 +02:00
i2c-boardinfo.c i2c: remove FSF address 2014-11-07 18:35:33 +01:00
i2c-core.c i2c: allow specifying separate wakeup interrupt in device tree 2015-08-26 18:47:58 +02:00
i2c-core.h i2c: remove FSF address 2014-11-07 18:35:33 +01:00
i2c-dev.c i2c: remove FSF address 2014-11-07 18:35:33 +01:00
i2c-mux.c i2c: mux: Use __i2c_transfer() instead of calling parent's master_xfer() 2015-06-17 14:35:37 +02:00
i2c-slave-eeprom.c i2c: Drop owner assignment from i2c_driver 2015-08-10 08:37:35 +02:00
i2c-smbus.c i2c: smbus: fix typo in commet 2015-06-01 08:41:26 +09:00
i2c-stub.c i2c: remove FSF address 2014-11-07 18:35:33 +01:00
Kconfig kconfig: use bool instead of boolean for type definition attributes 2015-01-07 13:08:04 +01:00
Makefile i2c: slave-eeprom: add eeprom simulator driver 2014-12-11 22:25:54 +01:00