[v7,0/3] Add QCOM SNPS PHY overriding params support

Added support for overriding tuning parameters in QCOM SNPS PHY
from device tree. This parameter tuning is required to tune the
hs signal on dp/dm lines for electrical compliance to be successful.

changes in v7:
Fixed nitpick in driver code and dtsi file.

changes in v6:
Fixed errors in dt-bindings.
Fixed nitpick in driver code.

changes in v5:
Fixed nitpicks in code.
Added minimum and maximum for each parameter added in dt-bindings.
Added proper suffixes to each parameter as per dtschema.

changes in v4:
Fixed nitpicks in code.
Initial compliance test results showed overshoot in the middle of eye
diagram. The current dt values were put in place to correct it and fix
overshoot issue.

changes in v3:
Added support for phy tuning parameters to be represented in bps and
corresponding register values to be written are obtained by traversing
through data map declared in the driver.

changes in v2:
Reading the individual fields in each overriding register from
device tree.

Krishna Kurapati (2):
  phy: qcom-snps: Add support for overriding phy tuning parameters
  arm64: dts: qcom: sc7280: Update SNPS Phy params for SC7280 IDP device

Sandeep Maheswaram (1):
  dt-bindings: phy: qcom,usb-snps-femto-v2: Add phy override params
    bindings

 .../bindings/phy/qcom,usb-snps-femto-v2.yaml       |  96 ++++++++
 arch/arm64/boot/dts/qcom/sc7280-idp.dtsi           |   6 +
 drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c      | 268 ++++++++++++++++++++-
 3 files changed, 368 insertions(+), 2 deletions(-)

On Tue, May 31, 2022 at 09:44:52PM +0530, Krishna Kurapati wrote:
> Add support for overriding electrical signal tuning parameters for
> SNPS HS Phy.
> 
> Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com>
> ---
>  drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c | 268 +++++++++++++++++++++++++-
>  1 file changed, 266 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c b/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c
> index 5d20378..3a17216 100644
> --- a/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c
> +++ b/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c
> @@ -52,6 +52,12 @@
>  #define USB2_SUSPEND_N				BIT(2)
>  #define USB2_SUSPEND_N_SEL			BIT(3)
>  

<snip>

> +static void qcom_snps_hsphy_override_param_update_val(
> +			const struct override_param_map map,
> +			s32 dt_val, struct phy_override_seq *seq_entry)
> +{
> +	int i;
> +
> +	/*
> +	 * Param table for each param is in increasing order
> +	 * of dt values. We need to iterate over the list to
> +	 * select the entry that has equal or the next highest value.
> +	 */
> +	for (i = 0; i < map.table_size - 1; i++) {
> +		if (map.param_table[i].value >= dt_val)
> +			break;
> +	}
> +
> +	seq_entry->need_update = true;
> +	seq_entry->offset = map.reg_offset;
> +	seq_entry->mask = map.param_mask;
> +	seq_entry->value =  map.param_table[i].reg << __ffs(map.param_mask);
> +}
> +
> +static void qcom_snps_hsphy_read_override_param_seq(struct device *dev)
> +{
> +	struct device_node *node = dev->of_node;
> +	s32 val;
> +	int ret, i;
> +	struct qcom_snps_hsphy *hsphy;
> +	const struct override_param_map *cfg =
> +		(struct override_param_map *) of_device_get_match_data(dev);

As mentioned in the previous patch-set, the explicit typecast is not needed.

overall, looks good to me. After fixing the above, feel free to use

Reviewed-by: Pavankumar Kondeti <quic_pkondeti@quicinc.com>

Thanks,
Pavan

On 6/1/2022 7:38 AM, Pavan Kondeti wrote:
> On Tue, May 31, 2022 at 09:44:52PM +0530, Krishna Kurapati wrote:
>> Add support for overriding electrical signal tuning parameters for
>> SNPS HS Phy.
>>
>> Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com>
>> ---
>>   drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c | 268 +++++++++++++++++++++++++-
>>   1 file changed, 266 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c b/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c
>> index 5d20378..3a17216 100644
>> --- a/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c
>> +++ b/drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c
>> @@ -52,6 +52,12 @@
>>   #define USB2_SUSPEND_N				BIT(2)
>>   #define USB2_SUSPEND_N_SEL			BIT(3)
>>   
> <snip>
>
>> +static void qcom_snps_hsphy_override_param_update_val(
>> +			const struct override_param_map map,
>> +			s32 dt_val, struct phy_override_seq *seq_entry)
>> +{
>> +	int i;
>> +
>> +	/*
>> +	 * Param table for each param is in increasing order
>> +	 * of dt values. We need to iterate over the list to
>> +	 * select the entry that has equal or the next highest value.
>> +	 */
>> +	for (i = 0; i < map.table_size - 1; i++) {
>> +		if (map.param_table[i].value >= dt_val)
>> +			break;
>> +	}
>> +
>> +	seq_entry->need_update = true;
>> +	seq_entry->offset = map.reg_offset;
>> +	seq_entry->mask = map.param_mask;
>> +	seq_entry->value =  map.param_table[i].reg << __ffs(map.param_mask);
>> +}
>> +
>> +static void qcom_snps_hsphy_read_override_param_seq(struct device *dev)
>> +{
>> +	struct device_node *node = dev->of_node;
>> +	s32 val;
>> +	int ret, i;
>> +	struct qcom_snps_hsphy *hsphy;
>> +	const struct override_param_map *cfg =
>> +		(struct override_param_map *) of_device_get_match_data(dev);
> As mentioned in the previous patch-set, the explicit typecast is not needed.
>
> overall, looks good to me. After fixing the above, feel free to use
>
> Reviewed-by: Pavankumar Kondeti <quic_pkondeti@quicinc.com>
>
> Thanks,
> Pavan
My bad, Thanks for the review Pavan. Will fix it in the next patch.