On Wed, Jun 15, 2022 at 02:12:13PM -0500, Dinh Nguyen wrote:
> The I2C pins on the SoCFPGA platforms do not go through a GPIO module,
> thus cannot be recovered by the default method of by doing a GPIO access.
> Only a reset of the I2C IP block can a recovery be successful.
>
> The assignment of the recover_bus needs to get done before the call to
> devm_gpiod_get_optional(), otherwise, the assignment is not taking place
> because of an error after returning from devm_gpiod_get_optional().
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
(yes, assuming stray change goes away)
> Signed-off-by: Dinh Nguyen <dinguyen@xxxxxxxxxx>
> ---
> v4: re-arrange code per Andy Shevchenko's recommendation
> v3: simplify the function
> update commit message
> v2: remove change to MODEL_MASK
> s/i2c_custom_scl_recovery/i2c_socfpga_scl_recovery
> ---
> drivers/i2c/busses/i2c-designware-core.h | 1 +
> drivers/i2c/busses/i2c-designware-master.c | 50 ++++++++++++++++++---
> drivers/i2c/busses/i2c-designware-platdrv.c | 1 +
> 3 files changed, 46 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h
> index 70b80e710990..7b22ec1d6a96 100644
> --- a/drivers/i2c/busses/i2c-designware-core.h
> +++ b/drivers/i2c/busses/i2c-designware-core.h
> @@ -303,6 +303,7 @@ struct dw_i2c_dev {
> #define MODEL_MSCC_OCELOT BIT(8)
> #define MODEL_BAIKAL_BT1 BIT(9)
> #define MODEL_AMD_NAVI_GPU BIT(10)
> +#define MODEL_SOCFPGA BIT(11)
> #define MODEL_MASK GENMASK(11, 8)
>
> /*
> diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c
> index 44a94b225ed8..6b75a08a1c1f 100644
> --- a/drivers/i2c/busses/i2c-designware-master.c
> +++ b/drivers/i2c/busses/i2c-designware-master.c
> @@ -813,10 +813,26 @@ static void i2c_dw_unprepare_recovery(struct i2c_adapter *adap)
> i2c_dw_init_master(dev);
> }
>
> -static int i2c_dw_init_recovery_info(struct dw_i2c_dev *dev)
> +static int i2c_socfpga_scl_recovery(struct i2c_adapter *adap)
> +{
> + struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
> +
> + bri->prepare_recovery(adap);
> + bri->unprepare_recovery(adap);
> +
> + return 0;
> +}
> +
> +static int i2c_dw_init_socfpga_recovery_info(struct dw_i2c_dev *dev,
> + struct i2c_bus_recovery_info *rinfo)
> +{
> + rinfo->recover_bus = i2c_socfpga_scl_recovery;
> + return 1;
> +}
> +
> +static int i2c_dw_init_generic_recovery_info(struct dw_i2c_dev *dev,
> + struct i2c_bus_recovery_info *rinfo)
> {
> - struct i2c_bus_recovery_info *rinfo = &dev->rinfo;
> - struct i2c_adapter *adap = &dev->adapter;
> struct gpio_desc *gpio;
>
> gpio = devm_gpiod_get_optional(dev->dev, "scl", GPIOD_OUT_HIGH);
> @@ -831,16 +847,38 @@ static int i2c_dw_init_recovery_info(struct dw_i2c_dev *dev)
> rinfo->sda_gpiod = gpio;
>
> rinfo->recover_bus = i2c_generic_scl_recovery;
> - rinfo->prepare_recovery = i2c_dw_prepare_recovery;
> - rinfo->unprepare_recovery = i2c_dw_unprepare_recovery;
> - adap->bus_recovery_info = rinfo;
>
> dev_info(dev->dev, "running with gpio recovery mode! scl%s",
> rinfo->sda_gpiod ? ",sda" : "");
>
> + return 1;
> +}
> +
> +static int i2c_dw_init_recovery_info(struct dw_i2c_dev *dev)
> +{
> + struct i2c_bus_recovery_info *rinfo = &dev->rinfo;
> + struct i2c_adapter *adap = &dev->adapter;
> + int ret;
> +
> + switch (dev->flags & MODEL_MASK) {
> + case MODEL_SOCFPGA:
> + ret = i2c_dw_init_socfpga_recovery_info(dev, rinfo);
> + break;
> + default:
> + ret = i2c_dw_init_generic_recovery_info(dev, rinfo);
> + break;
> + }
> + if (ret <= 0)
> + return ret;
> +
> + rinfo->prepare_recovery = i2c_dw_prepare_recovery;
> + rinfo->unprepare_recovery = i2c_dw_unprepare_recovery;
> + adap->bus_recovery_info = rinfo;
> +
> return 0;
> }
>
> +
> static int amd_i2c_adap_quirk(struct dw_i2c_dev *dev)
> {
> struct i2c_adapter *adap = &dev->adapter;
> diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
> index 70ade5306e45..b33e015e6732 100644
> --- a/drivers/i2c/busses/i2c-designware-platdrv.c
> +++ b/drivers/i2c/busses/i2c-designware-platdrv.c
> @@ -153,6 +153,7 @@ static const struct of_device_id dw_i2c_of_match[] = {
> { .compatible = "snps,designware-i2c", },
> { .compatible = "mscc,ocelot-i2c", .data = (void *)MODEL_MSCC_OCELOT },
> { .compatible = "baikal,bt1-sys-i2c", .data = (void *)MODEL_BAIKAL_BT1 },
> + { .compatible = "intel,socfpga-i2c", .data = (void *)MODEL_SOCFPGA },
> {},
> };
> MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
> --
> 2.25.1
>
--
With Best Regards,
Andy Shevchenko
