The designware block is not always properly disabled in the case of
transfer errors. Interrupts from aborted transfers might be handled
after the data structures for the following transfer are initialised but
before the hardware is set up. This can corrupt the data structures to
the point that the system is stuck in an infinite interrupt loop (where
FIFOs are never emptied because dev->msg_read_idx == dev->msgs_num).
This patch cleanly disables the designware-i2c hardware at the end of
every transfer, be it successful or not.
Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
[wsa: extended the comment]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
If a process receives signal while it is waiting for I2C transfer to
complete, an error is returned to the caller and the transfer is aborted.
This can cause the driver to fail subsequent transfers. Also according to
commit d295a86eab (i2c: mv64xxx: work around signals causing I2C
transactions to be aborted) I2C drivers aren't supposed to abort
transactions on signals.
To prevent this switch to use wait_for_completion_timeout() instead of
wait_for_completion_interruptible_timeout() in the designware I2C driver.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Christian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
If the I2C bus is put to a low power state by an ACPI method it might pull
the SDA line low (as its power is removed). Once the bus is put to full
power state again, the SDA line is pulled back to high. This transition
looks like a STOP condition from the controller point-of-view which sets
STOP detected bit in its status register causing the driver to fail
subsequent transfers.
Fix this by always clearing all interrupts before we start a transfer.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
i2c_dw_xfer_msg() pushes a number of bytes to transmit/receive
to/from the bus into the TX FIFO.
For master-rx transactions, the maximum amount of data that can be
received is calculated depending solely on TX and RX FIFO load.
This is racy - TX FIFO may contain master-rx data yet to be
processed, which will eventually land into the RX FIFO. This
data is not taken into account and the function may request more
data than the controller is actually capable of storing.
This patch ensures the driver takes into account the outstanding
master-rx data in TX FIFO to prevent RX FIFO overrun.
Signed-off-by: Josef Ahmad <josef.ahmad@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org
Using autosuspend helps to reduce the resume latency in situations where
another I2C message is going to be started soon. For example with HID over
I2C touch panels we get several messages in a short period of time while
the touch panel is in use.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This is not an atomic context so there is no need to use mdelay() but
instead use usleep_range().
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The correct way to disable or enable the controller is to wait until the
DW_IC_ENABLE_STATUS register bit matches the bit we program into DW_IC_ENABLE
register. This procedure is described in the DesignWare I2C databook.
By doing this we can be sure that the controller is in correct state once
the function returns.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
If IC_EMPTYFIFO_HOLD_MASTER_EN is set to one, the DesignWare I2C controller
doesn't generate STOP on the bus when the FIFO is empty. This violates the
rules of Linux I2C stack as it requires that the STOP is issued once the
i2c_transfer() is finished.
However, there is no way to detect this from the hardware registers, so we
must make sure that the STOP bit is always set once the last byte of the
last message is transferred.
This patch is based on the work of Dirk Brandewie.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
The driver can also be built as a module so add MODULE_LICENSE for it. In
addition add MODULE_DESCRIPTION as well.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
i2c_dw_xfer_msg is only called internally so it can be static. It
original was, before the driver split. No idea why it was changed at
that time.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Dirk Brandewie <dirk.brandewie@gmail.com>
This patch adds config I2C_DESIGNWARE_CORE in Kconfig, and let
I2C_DESIGNWARE_PLATFORM and I2C_DESIGNWARE_PCI select I2C_DESIGNWARE_CORE.
Because both I2C_DESIGNWARE_PLATFORM and I2C_DESIGNWARE_PCI can be built as
built-in or module, we also need to export the functions in i2c-designware-core.
This fixes below build error when CONFIG_I2C_DESIGNWARE_PLATFORM=y &&
CONFIG_I2C_DESIGNWARE_PCI=y:
LD drivers/i2c/busses/built-in.o
drivers/i2c/busses/i2c-designware-pci.o: In function `i2c_dw_clear_int':
i2c-designware-core.c:(.text+0xa10): multiple definition of `i2c_dw_clear_int'
drivers/i2c/busses/i2c-designware-platform.o:i2c-designware-platdrv.c:(.text+0x928): first defined here
drivers/i2c/busses/i2c-designware-pci.o: In function `i2c_dw_init':
i2c-designware-core.c:(.text+0x178): multiple definition of `i2c_dw_init'
drivers/i2c/busses/i2c-designware-platform.o:i2c-designware-platdrv.c:(.text+0x90): first defined here
drivers/i2c/busses/i2c-designware-pci.o: In function `dw_readl':
i2c-designware-core.c:(.text+0xe8): multiple definition of `dw_readl'
drivers/i2c/busses/i2c-designware-platform.o:i2c-designware-platdrv.c:(.text+0x0): first defined here
drivers/i2c/busses/i2c-designware-pci.o: In function `i2c_dw_isr':
i2c-designware-core.c:(.text+0x724): multiple definition of `i2c_dw_isr'
drivers/i2c/busses/i2c-designware-platform.o:i2c-designware-platdrv.c:(.text+0x63c): first defined here
drivers/i2c/busses/i2c-designware-pci.o: In function `i2c_dw_xfer':
i2c-designware-core.c:(.text+0x4b0): multiple definition of `i2c_dw_xfer'
drivers/i2c/busses/i2c-designware-platform.o:i2c-designware-platdrv.c:(.text+0x3c8): first defined here
drivers/i2c/busses/i2c-designware-pci.o: In function `i2c_dw_is_enabled':
i2c-designware-core.c:(.text+0x9d4): multiple definition of `i2c_dw_is_enabled'
drivers/i2c/busses/i2c-designware-platform.o:i2c-designware-platdrv.c:(.text+0x8ec): first defined here
drivers/i2c/busses/i2c-designware-pci.o: In function `dw_writel':
i2c-designware-core.c:(.text+0x124): multiple definition of `dw_writel'
drivers/i2c/busses/i2c-designware-platform.o:i2c-designware-platdrv.c:(.text+0x3c): first defined here
drivers/i2c/busses/i2c-designware-pci.o: In function `i2c_dw_xfer_msg':
i2c-designware-core.c:(.text+0x2e8): multiple definition of `i2c_dw_xfer_msg'
drivers/i2c/busses/i2c-designware-platform.o:i2c-designware-platdrv.c:(.text+0x200): first defined here
drivers/i2c/busses/i2c-designware-pci.o: In function `i2c_dw_enable':
i2c-designware-core.c:(.text+0x9c8): multiple definition of `i2c_dw_enable'
drivers/i2c/busses/i2c-designware-platform.o:i2c-designware-platdrv.c:(.text+0x8e0): first defined here
drivers/i2c/busses/i2c-designware-pci.o: In function `i2c_dw_read_comp_param':
i2c-designware-core.c:(.text+0xa24): multiple definition of `i2c_dw_read_comp_param'
drivers/i2c/busses/i2c-designware-platform.o:i2c-designware-platdrv.c:(.text+0x93c): first defined here
drivers/i2c/busses/i2c-designware-pci.o: In function `i2c_dw_disable':
i2c-designware-core.c:(.text+0x9dc): multiple definition of `i2c_dw_disable'
drivers/i2c/busses/i2c-designware-platform.o:i2c-designware-platdrv.c:(.text+0x8f4): first defined here
drivers/i2c/busses/i2c-designware-pci.o: In function `i2c_dw_func':
i2c-designware-core.c:(.text+0x710): multiple definition of `i2c_dw_func'
drivers/i2c/busses/i2c-designware-platform.o:i2c-designware-platdrv.c:(.text+0x628): first defined here
drivers/i2c/busses/i2c-designware-pci.o: In function `i2c_dw_disable_int':
i2c-designware-core.c:(.text+0xa18): multiple definition of `i2c_dw_disable_int'
drivers/i2c/busses/i2c-designware-platform.o:i2c-designware-platdrv.c:(.text+0x930): first defined here
make[3]: *** [drivers/i2c/busses/built-in.o] Error 1
make[2]: *** [drivers/i2c/busses] Error 2
make[1]: *** [drivers/i2c] Error 2
make: *** [drivers] Error 2
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Tested-by: Jiri Slaby <jslaby@suse.cz>
Cc: stable@vger.kernel.org [3.2+]
The STM SPEAr platform can only access the i2c controller register
via 16bit read/write functions. This patch adds support to
automatically detect this 16bit access mode.
Signed-off-by: Stefan Roese <sr@denx.de>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Add runtime power management to the PCI driver.
Signed-off-by: Dirk Brandewie <dirk.brandewie@gmail.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Move all register manipulation code into the core, also move register
offset definitions to i2c-designware-core.c since the bus specific
portions of the driver no longer need/use them.
Signed-off-by: Dirk Brandewie <dirk.brandewie@gmail.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Add check to make sure that the core is enabled and has outstanding
interrupts. The activity bit is masked due to the fact that it will
stay active even after the controller has been disabled until the
contoller internal state machines have settled.
Signed-off-by: Dirk Brandewie <dirk.brandewie@gmail.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
With multiple I2C adapters possible in the system each running at
(possibly) different speeds we need to move the controller
configuration bit field to the adapter.
Signed-off-by: Dirk Brandewie <dirk.brandewie@gmail.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
The functionality of the adapter depends on the configuration of the
IP block at silicon compile time and is adapter specific.
Signed-off-by: Dirk Brandewie <dirk.brandewie@gmail.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
The clock frequecy supplied to the IP core is specific to a single
instance of the driver. This patch makes it possible to have multiple
Designware I2C cores in the system possibly running at different core
frequencies.
Signed-off-by: Dirk Brandewie <dirk.brandewie@gmail.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
This patch splits i2c-designware.c into three pieces:
i2c-designware-core.c, contains the code that interacts directly
with the core.
i2c-designware-platdrv.c, contains the code specific to the
platform driver using the core.
i2c-designware-core.h contains the definitions and declareations
shared by i2c-designware-core.c and i2c-designware-platdrv.c.
This patch is the first in a set to allow multiple instances of the
designware I2C core in the system.
Signed-off-by: Dirk Brandewie <dirk.brandewie@gmail.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Christian Ruppert