Re: [PATCH v1] i2c: designware: Add support to get I2C related timing parameters from firmware.

Andy Shevchenko
2022-09-07T16:26:31Z

On Wed, Sep 07, 2022 at 09:39:20PM +0530, Sudarshan Ravula wrote:
> Similar to I2C designware platform driver add i2c_parse_fw_timings() in
> PCI driver, to get I2C related timing parameters from firmware.
>
> Signed-off-by: Sudarshan Ravula <sudarshan.ravula@intel.com>
> Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
> drivers/i2c/busses/i2c-designware-pcidrv.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/i2c/busses/i2c-designware-pcidrv.c b/drivers/i2c/busses/i2c-designware-pcidrv.c
> index 608e61209455..c001719209be 100644
> --- a/drivers/i2c/busses/i2c-designware-pcidrv.c
> +++ b/drivers/i2c/busses/i2c-designware-pcidrv.c
> @@ -243,6 +243,7 @@ static int i2c_dw_pci_probe(struct pci_dev *pdev,
> int r;
> struct dw_pci_controller *controller;
> struct dw_scl_sda_cfg *cfg;
> + struct i2c_timings *t;
>
> if (id->driver_data >= ARRAY_SIZE(dw_pci_controllers))
> return dev_err_probe(&pdev->dev, -EINVAL,
> @@ -272,12 +273,14 @@ static int i2c_dw_pci_probe(struct pci_dev *pdev,
> return r;
>
> dev->get_clk_rate_khz = controller->get_clk_rate_khz;
> - dev->timings.bus_freq_hz = I2C_MAX_FAST_MODE_FREQ;
> dev->base = pcim_iomap_table(pdev)[0];
> dev->dev = &pdev->dev;
> dev->irq = pci_irq_vector(pdev, 0);
> dev->flags |= controller->flags;
>
> + t = &dev->timings;
> + i2c_parse_fw_timings(&pdev->dev, t, false);

Note that this is safe to drop above assignment with 'false' given here since
i2c_dw_adjust_bus_speed(), which is called after, will set that default and if
nothing is read from firmware the value of bus_freq_hz will be 0 as guaranteed
by kzalloc().

> +
> pci_set_drvdata(pdev, dev);
>
> if (controller->setup) {
> --
> 2.17.1
>

--
With Best Regards,
Andy Shevchenko