When in slave mode, an arbitration loss (ARLO) may be detected before the
slave had a chance to detect the stop condition (STOPF in ISR).
This is seen when two master + slave adapters switch their roles. It
provokes the i2c bus to be stuck, busy as SCL line is stretched.
- the I2C_SLAVE_STOP event is never generated due to STOPF flag is set but
don't generate an irq (race with ARLO irq, STOPIE is masked). STOPF flag
remains set until next master xfer (e.g. when STOPIE irq get unmasked).
In this case, completion is generated too early: immediately upon new
transfer request (then it doesn't send all data).
- Some data get stuck in TXDR register. As a consequence, the controller
stretches the SCL line: the bus gets busy until a future master transfer
triggers the bus busy / recovery mechanism (this can take time... and
may never happen at all)
So choice is to let the STOPF being detected by the slave isr handler,
to properly handle this stop condition. E.g. don't mask IRQs in error
handler, when the slave is running.
Fixes: 60d609f30d ("i2c: i2c-stm32f7: Add slave support")
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The slave-interface documentation [1] states "the bus driver should
transmit the first byte" upon I2C_SLAVE_READ_REQUESTED slave event:
- 'val': backend returns first byte to be sent
The driver currently ignores the 1st byte to send on this event.
[1] https://www.kernel.org/doc/Documentation/i2c/slave-interface
Fixes: 60d609f30d ("i2c: i2c-stm32f7: Add slave support")
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Static structure stm32f7_i2c_algo, of type i2c_algorithm, is used only
when it is assigned to constant field algo of a variable having type
i2c_adapter. As stm32f7_i2c_algo is therefore never modified, make it
const as well to protect it from unintended modification.
Issue found with Coccinelle.
Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com>
Acked-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This patch adds the support of I2C_SMBUS_I2C_BLOCK_DATA transaction type
for the stm32f7 SMBUS Controller.
Use emulated I2C_SMBUS_I2C_BLOCK_DATA transactions as there is no specific
hardware in STM32 I2C to manage this (e.g. like no need for PEC here).
Emulated transfer will fall back calling i2c transfer method where there's
already support for DMAs for example.
So, use the I2C_FUNC_SMBUS_I2C_BLOCK in stm32f7_i2c_func(), and rely on
emulated transfer by returning -EOPNOTSUPP in the smbus_xfer() routine
for such a case.
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
During probe, return the "get_irq" error value instead of -EINVAL which
allows the driver to be deferred probed if needed.
Fix also the case where of_irq_get() returns a negative value.
Note :
On failure of_irq_get() returns 0 or a negative value while
platform_get_irq() returns a negative value.
Fixes: aeb068c572 ("i2c: i2c-stm32f7: add driver")
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Fabien Dessenne <fabien.dessenne@st.com>
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This avoids useless loops inside the I2C timing algorithm.
Actually, we support only one possible solution per prescaler value.
So after finding a solution with a prescaler, the algorithm can
switch directly to the next prescaler value.
Signed-off-by: Nicolas Le Bayon <nicolas.le.bayon@st.com>
Signed-off-by: Bich Hemon <bich.hemon@st.com>
Reviewed-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Use PM Runtime API to enable/disable clock
Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Read SYSCFG bindings to set Fast Mode Plus bits if Fast Mode Plus
speed is selected.
Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Some data structure members were either misspelled or missing.
Fixes: aeb068c572 ("i2c: i2c-stm32f7: add driver")
Fixes: 380b8a85e7 ("i2c: i2c-stm32f7: Add initial SMBus protocols support")
Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This patch adds slave support for I2C controller embedded in STM32F7 SoC
Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This patch adds support for 10-bit device address for STM32F7 I2C
Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The structure stm32f7_setup is local to the source and does not need
to be in global scope, make it static const.
Cleans up sparse warning:
symbol 'stm32f7_setup' was not declared. Should it be static?
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
I2C drive setup structure is not properly allocated.
Make it static instead of pointer to store driver data.
Fixes: aeb068c572 ("i2c: i2c-stm32f7: add driver")
Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This patch adds initial support for the STM32F7 I2C controller.
Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Fabrice Gasnier