Messages in this thread | | | Subject | Re: [RESEND PATCH v1 6/6] i2c: i2c-stm32f7: Implement I2C recovery mechanism | From | Phil Reid <> | Date | Mon, 19 Mar 2018 17:36:30 +0800 |
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On 12/03/2018 18:53, Pierre-Yves MORDRET wrote: > Feature prevents I2C lock-ups. Mechanism resets I2C state machine > and releases SCL/SDA signals but preserves I2C registers. > > Signed-off-by: Pierre-Yves MORDRET <pierre-yves.mordret@st.com> > --- > Version history: > v1: > * Initial > --- > --- > drivers/i2c/busses/i2c-stm32f7.c | 32 +++++++++++++++++++++++++++++--- > 1 file changed, 29 insertions(+), 3 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c > index 69a2e5e..3808bc9 100644 > --- a/drivers/i2c/busses/i2c-stm32f7.c > +++ b/drivers/i2c/busses/i2c-stm32f7.c > @@ -718,6 +718,20 @@ static void stm32f7_i2c_smbus_reload(struct stm32f7_i2c_dev *i2c_dev) > writel_relaxed(cr2, i2c_dev->base + STM32F7_I2C_CR2); > } > > +static int stm32f7_i2c_recover_bus(struct i2c_adapter *i2c_adap) > +{ > + struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(i2c_adap); > + > + dev_info(i2c_dev->dev, "Trying to recover bus\n"); > + > + stm32f7_i2c_clr_bits(i2c_dev->base + STM32F7_I2C_CR1, > + STM32F7_I2C_CR1_PE);
This only "releases" the scl / sda on the stm32f7 end (outputs are hiz I guess). It doesn't trigger the scl clocking needed to recover a stuck device via i2c recovery from what I can see in the data sheet.
> + > + stm32f7_i2c_hw_config(i2c_dev);
Nothing in here either I think.
> + > + return 0; > +} > + > static int stm32f7_i2c_wait_free_bus(struct stm32f7_i2c_dev *i2c_dev) > { > u32 status; > @@ -727,12 +741,18 @@ static int stm32f7_i2c_wait_free_bus(struct stm32f7_i2c_dev *i2c_dev) > status, > !(status & STM32F7_I2C_ISR_BUSY), > 10, 1000); > + if (!ret) > + return 0; > + > + dev_info(i2c_dev->dev, "bus busy\n"); > + > + ret = i2c_recover_bus(&i2c_dev->adap); > if (ret) { > - dev_dbg(i2c_dev->dev, "bus busy\n"); > - ret = -EBUSY; > + dev_err(i2c_dev->dev, "Failed to recover the bus (%d)\n", ret); > + return ret; > } > > - return ret; > + return -EBUSY; > } > > static void stm32f7_i2c_xfer_msg(struct stm32f7_i2c_dev *i2c_dev, > @@ -1476,6 +1496,7 @@ static irqreturn_t stm32f7_i2c_isr_error(int irq, void *data) > if (status & STM32F7_I2C_ISR_BERR) { > dev_err(dev, "<%s>: Bus error\n", __func__); > writel_relaxed(STM32F7_I2C_ICR_BERRCF, base + STM32F7_I2C_ICR); > + i2c_recover_bus(&i2c_dev->adap); > f7_msg->result = -EIO; > } > > @@ -1760,6 +1781,10 @@ static struct i2c_algorithm stm32f7_i2c_algo = { > .unreg_slave = stm32f7_i2c_unreg_slave, > }; > > +static struct i2c_bus_recovery_info stm32f7_i2c_recovery_info = { > + .recover_bus = stm32f7_i2c_recover_bus, > +}; > + > static int stm32f7_i2c_probe(struct platform_device *pdev) > { > struct device_node *np = pdev->dev.of_node; > @@ -1879,6 +1904,7 @@ static int stm32f7_i2c_probe(struct platform_device *pdev) > adap->algo = &stm32f7_i2c_algo; > adap->dev.parent = &pdev->dev; > adap->dev.of_node = pdev->dev.of_node; > + adap->bus_recovery_info = &stm32f7_i2c_recovery_info; > > init_completion(&i2c_dev->complete); > >
-- Regards Phil
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