diff mbox series

[3/7] phy: qcom: qmp-pcie: register second optional PHY AUX clock

Message ID 20240319-topic-sm8x50-upstream-pcie-1-phy-aux-clk-v1-3-926d7a4ccd80@linaro.org (mailing list archive)
State Superseded
Headers show
Series arm64: qcom-sm8[456]50: properly describe the PCIe Gen4x2 PHY AUX clock | expand

Commit Message

Neil Armstrong March 19, 2024, 10:44 a.m. UTC
The PCIe Gen4x2 PHY found in the SM8[456]50 SoCs have a second clock,
add the code to register it for PHYs configs that sets a aux_clock_rate.

In order to get the right clock, add qmp_pcie_clk_hw_get() which uses
the newly introduced QMP_PCIE_PIPE_CLK & QMP_PCIE_PHY_AUX_CLK clock
IDs and also supports the legacy bindings by returning the PIPE clock.

Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
---
 drivers/phy/qualcomm/phy-qcom-qmp-pcie.c | 70 ++++++++++++++++++++++++++++++++
 1 file changed, 70 insertions(+)

Comments

Dmitry Baryshkov March 19, 2024, 10:55 a.m. UTC | #1
On Tue, 19 Mar 2024 at 12:45, Neil Armstrong <neil.armstrong@linaro.org> wrote:
>
> The PCIe Gen4x2 PHY found in the SM8[456]50 SoCs have a second clock,
> add the code to register it for PHYs configs that sets a aux_clock_rate.
>
> In order to get the right clock, add qmp_pcie_clk_hw_get() which uses
> the newly introduced QMP_PCIE_PIPE_CLK & QMP_PCIE_PHY_AUX_CLK clock
> IDs and also supports the legacy bindings by returning the PIPE clock.
>
> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
> ---
>  drivers/phy/qualcomm/phy-qcom-qmp-pcie.c | 70 ++++++++++++++++++++++++++++++++
>  1 file changed, 70 insertions(+)
>
> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
> index 079b3e306489..2d05226ae200 100644
> --- a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
> +++ b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
> @@ -22,6 +22,8 @@
>  #include <linux/reset.h>
>  #include <linux/slab.h>
>
> +#include <dt-bindings/phy/phy-qcom-qmp.h>
> +
>  #include "phy-qcom-qmp-common.h"
>
>  #include "phy-qcom-qmp.h"
> @@ -2389,6 +2391,9 @@ struct qmp_phy_cfg {
>
>         /* QMP PHY pipe clock interface rate */
>         unsigned long pipe_clock_rate;
> +
> +       /* QMP PHY AUX clock interface rate */
> +       unsigned long aux_clock_rate;
>  };
>
>  struct qmp_pcie {
> @@ -2420,6 +2425,7 @@ struct qmp_pcie {
>         int mode;
>
>         struct clk_fixed_rate pipe_clk_fixed;
> +       struct clk_fixed_rate aux_clk_fixed;
>  };
>
>  static inline void qphy_setbits(void __iomem *base, u32 offset, u32 val)
> @@ -3681,6 +3687,62 @@ static int phy_pipe_clk_register(struct qmp_pcie *qmp, struct device_node *np)
>         return devm_clk_hw_register(qmp->dev, &fixed->hw);
>  }
>
> +/*
> + * Register a fixed rate PHY aux clock.
> + *
> + * The <s>_phy_aux_clksrc generated by PHY goes to the GCC that gate
> + * controls it. The <s>_phy_aux_clk coming out of the GCC is requested
> + * by the PHY driver for its operations.
> + * We register the <s>_phy_aux_clksrc here. The gcc driver takes care
> + * of assigning this <s>_phy_aux_clksrc as parent to <s>_phy_aux_clk.
> + * Below picture shows this relationship.
> + *
> + *         +---------------+
> + *         |   PHY block   |<<---------------------------------------------+
> + *         |               |                                               |
> + *         |   +-------+   |                      +-----+                  |
> + *   I/P---^-->|  PLL  |---^--->phy_aux_clksrc--->| GCC |--->phy_aux_clk---+
> + *    clk  |   +-------+   |                      +-----+
> + *         +---------------+
> + */
> +static int phy_aux_clk_register(struct qmp_pcie *qmp, struct device_node *np)
> +{
> +       struct clk_fixed_rate *fixed = &qmp->aux_clk_fixed;
> +       struct clk_init_data init = { };
> +       int ret;
> +
> +       ret = of_property_read_string_index(np, "clock-output-names", 1, &init.name);
> +       if (ret) {
> +               dev_err(qmp->dev, "%pOFn: No clock-output-names index 1\n", np);
> +               return ret;
> +       }
> +
> +       init.ops = &clk_fixed_rate_ops;
> +
> +       fixed->fixed_rate = qmp->cfg->aux_clock_rate;
> +       fixed->hw.init = &init;
> +
> +       return devm_clk_hw_register(qmp->dev, &fixed->hw);
> +}
> +
> +static struct clk_hw *qmp_pcie_clk_hw_get(struct of_phandle_args *clkspec, void *data)
> +{
> +       struct qmp_pcie *qmp = data;
> +
> +       /* Support legacy bindings */
> +       if (!clkspec->args_count)
> +               return &qmp->pipe_clk_fixed.hw;
> +
> +       switch (clkspec->args[0]) {
> +       case QMP_PCIE_PIPE_CLK:
> +               return &qmp->pipe_clk_fixed.hw;
> +       case QMP_PCIE_PHY_AUX_CLK:
> +               return &qmp->aux_clk_fixed.hw;
> +       }
> +
> +       return ERR_PTR(-EINVAL);
> +}

Can we use of_clk_hw_onecell_get() instead? I think it even should be
possible to use onecell for both cases, it will look at the first arg,
which will be 0 in case of #clock-cells equal to 0.

> +
>  static int qmp_pcie_register_clocks(struct qmp_pcie *qmp, struct device_node *np)
>  {
>         int ret;
> @@ -3689,6 +3751,14 @@ static int qmp_pcie_register_clocks(struct qmp_pcie *qmp, struct device_node *np
>         if (ret)
>                 return ret;
>
> +       if (qmp->cfg->aux_clock_rate) {
> +               ret = phy_aux_clk_register(qmp, np);
> +               if (ret)
> +                       return ret;
> +
> +               return devm_of_clk_add_hw_provider(qmp->dev, qmp_pcie_clk_hw_get, qmp);
> +       }
> +
>         return devm_of_clk_add_hw_provider(qmp->dev, of_clk_hw_simple_get,
>                                            &qmp->pipe_clk_fixed.hw);
>  }
>
> --
> 2.34.1
>
>
Neil Armstrong March 19, 2024, 10:59 a.m. UTC | #2
On 19/03/2024 11:55, Dmitry Baryshkov wrote:
> On Tue, 19 Mar 2024 at 12:45, Neil Armstrong <neil.armstrong@linaro.org> wrote:
>>
>> The PCIe Gen4x2 PHY found in the SM8[456]50 SoCs have a second clock,
>> add the code to register it for PHYs configs that sets a aux_clock_rate.
>>
>> In order to get the right clock, add qmp_pcie_clk_hw_get() which uses
>> the newly introduced QMP_PCIE_PIPE_CLK & QMP_PCIE_PHY_AUX_CLK clock
>> IDs and also supports the legacy bindings by returning the PIPE clock.
>>
>> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
>> ---
>>   drivers/phy/qualcomm/phy-qcom-qmp-pcie.c | 70 ++++++++++++++++++++++++++++++++
>>   1 file changed, 70 insertions(+)
>>
>> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
>> index 079b3e306489..2d05226ae200 100644
>> --- a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
>> +++ b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
>> @@ -22,6 +22,8 @@
>>   #include <linux/reset.h>
>>   #include <linux/slab.h>
>>
>> +#include <dt-bindings/phy/phy-qcom-qmp.h>
>> +
>>   #include "phy-qcom-qmp-common.h"
>>
>>   #include "phy-qcom-qmp.h"
>> @@ -2389,6 +2391,9 @@ struct qmp_phy_cfg {
>>
>>          /* QMP PHY pipe clock interface rate */
>>          unsigned long pipe_clock_rate;
>> +
>> +       /* QMP PHY AUX clock interface rate */
>> +       unsigned long aux_clock_rate;
>>   };
>>
>>   struct qmp_pcie {
>> @@ -2420,6 +2425,7 @@ struct qmp_pcie {
>>          int mode;
>>
>>          struct clk_fixed_rate pipe_clk_fixed;
>> +       struct clk_fixed_rate aux_clk_fixed;
>>   };
>>
>>   static inline void qphy_setbits(void __iomem *base, u32 offset, u32 val)
>> @@ -3681,6 +3687,62 @@ static int phy_pipe_clk_register(struct qmp_pcie *qmp, struct device_node *np)
>>          return devm_clk_hw_register(qmp->dev, &fixed->hw);
>>   }
>>
>> +/*
>> + * Register a fixed rate PHY aux clock.
>> + *
>> + * The <s>_phy_aux_clksrc generated by PHY goes to the GCC that gate
>> + * controls it. The <s>_phy_aux_clk coming out of the GCC is requested
>> + * by the PHY driver for its operations.
>> + * We register the <s>_phy_aux_clksrc here. The gcc driver takes care
>> + * of assigning this <s>_phy_aux_clksrc as parent to <s>_phy_aux_clk.
>> + * Below picture shows this relationship.
>> + *
>> + *         +---------------+
>> + *         |   PHY block   |<<---------------------------------------------+
>> + *         |               |                                               |
>> + *         |   +-------+   |                      +-----+                  |
>> + *   I/P---^-->|  PLL  |---^--->phy_aux_clksrc--->| GCC |--->phy_aux_clk---+
>> + *    clk  |   +-------+   |                      +-----+
>> + *         +---------------+
>> + */
>> +static int phy_aux_clk_register(struct qmp_pcie *qmp, struct device_node *np)
>> +{
>> +       struct clk_fixed_rate *fixed = &qmp->aux_clk_fixed;
>> +       struct clk_init_data init = { };
>> +       int ret;
>> +
>> +       ret = of_property_read_string_index(np, "clock-output-names", 1, &init.name);
>> +       if (ret) {
>> +               dev_err(qmp->dev, "%pOFn: No clock-output-names index 1\n", np);
>> +               return ret;
>> +       }
>> +
>> +       init.ops = &clk_fixed_rate_ops;
>> +
>> +       fixed->fixed_rate = qmp->cfg->aux_clock_rate;
>> +       fixed->hw.init = &init;
>> +
>> +       return devm_clk_hw_register(qmp->dev, &fixed->hw);
>> +}
>> +
>> +static struct clk_hw *qmp_pcie_clk_hw_get(struct of_phandle_args *clkspec, void *data)
>> +{
>> +       struct qmp_pcie *qmp = data;
>> +
>> +       /* Support legacy bindings */
>> +       if (!clkspec->args_count)
>> +               return &qmp->pipe_clk_fixed.hw;
>> +
>> +       switch (clkspec->args[0]) {
>> +       case QMP_PCIE_PIPE_CLK:
>> +               return &qmp->pipe_clk_fixed.hw;
>> +       case QMP_PCIE_PHY_AUX_CLK:
>> +               return &qmp->aux_clk_fixed.hw;
>> +       }
>> +
>> +       return ERR_PTR(-EINVAL);
>> +}
> 
> Can we use of_clk_hw_onecell_get() instead? I think it even should be
> possible to use onecell for both cases, it will look at the first arg,
> which will be 0 in case of #clock-cells equal to 0.

Let me investigate if it's possible

> 
>> +
>>   static int qmp_pcie_register_clocks(struct qmp_pcie *qmp, struct device_node *np)
>>   {
>>          int ret;
>> @@ -3689,6 +3751,14 @@ static int qmp_pcie_register_clocks(struct qmp_pcie *qmp, struct device_node *np
>>          if (ret)
>>                  return ret;
>>
>> +       if (qmp->cfg->aux_clock_rate) {
>> +               ret = phy_aux_clk_register(qmp, np);
>> +               if (ret)
>> +                       return ret;
>> +
>> +               return devm_of_clk_add_hw_provider(qmp->dev, qmp_pcie_clk_hw_get, qmp);
>> +       }
>> +
>>          return devm_of_clk_add_hw_provider(qmp->dev, of_clk_hw_simple_get,
>>                                             &qmp->pipe_clk_fixed.hw);
>>   }
>>
>> --
>> 2.34.1
>>
>>
> 
>
Neil Armstrong March 19, 2024, 2:35 p.m. UTC | #3
On 19/03/2024 11:59, Neil Armstrong wrote:
> On 19/03/2024 11:55, Dmitry Baryshkov wrote:
>> On Tue, 19 Mar 2024 at 12:45, Neil Armstrong <neil.armstrong@linaro.org> wrote:
>>>
>>> The PCIe Gen4x2 PHY found in the SM8[456]50 SoCs have a second clock,
>>> add the code to register it for PHYs configs that sets a aux_clock_rate.
>>>
>>> In order to get the right clock, add qmp_pcie_clk_hw_get() which uses
>>> the newly introduced QMP_PCIE_PIPE_CLK & QMP_PCIE_PHY_AUX_CLK clock
>>> IDs and also supports the legacy bindings by returning the PIPE clock.
>>>
>>> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
>>> ---
>>>   drivers/phy/qualcomm/phy-qcom-qmp-pcie.c | 70 ++++++++++++++++++++++++++++++++
>>>   1 file changed, 70 insertions(+)
>>>
>>> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
>>> index 079b3e306489..2d05226ae200 100644
>>> --- a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
>>> +++ b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
>>> @@ -22,6 +22,8 @@
>>>   #include <linux/reset.h>
>>>   #include <linux/slab.h>
>>>
>>> +#include <dt-bindings/phy/phy-qcom-qmp.h>
>>> +
>>>   #include "phy-qcom-qmp-common.h"
>>>
>>>   #include "phy-qcom-qmp.h"
>>> @@ -2389,6 +2391,9 @@ struct qmp_phy_cfg {
>>>
>>>          /* QMP PHY pipe clock interface rate */
>>>          unsigned long pipe_clock_rate;
>>> +
>>> +       /* QMP PHY AUX clock interface rate */
>>> +       unsigned long aux_clock_rate;
>>>   };
>>>
>>>   struct qmp_pcie {
>>> @@ -2420,6 +2425,7 @@ struct qmp_pcie {
>>>          int mode;
>>>
>>>          struct clk_fixed_rate pipe_clk_fixed;
>>> +       struct clk_fixed_rate aux_clk_fixed;
>>>   };
>>>
>>>   static inline void qphy_setbits(void __iomem *base, u32 offset, u32 val)
>>> @@ -3681,6 +3687,62 @@ static int phy_pipe_clk_register(struct qmp_pcie *qmp, struct device_node *np)
>>>          return devm_clk_hw_register(qmp->dev, &fixed->hw);
>>>   }
>>>
>>> +/*
>>> + * Register a fixed rate PHY aux clock.
>>> + *
>>> + * The <s>_phy_aux_clksrc generated by PHY goes to the GCC that gate
>>> + * controls it. The <s>_phy_aux_clk coming out of the GCC is requested
>>> + * by the PHY driver for its operations.
>>> + * We register the <s>_phy_aux_clksrc here. The gcc driver takes care
>>> + * of assigning this <s>_phy_aux_clksrc as parent to <s>_phy_aux_clk.
>>> + * Below picture shows this relationship.
>>> + *
>>> + *         +---------------+
>>> + *         |   PHY block   |<<---------------------------------------------+
>>> + *         |               |                                               |
>>> + *         |   +-------+   |                      +-----+                  |
>>> + *   I/P---^-->|  PLL  |---^--->phy_aux_clksrc--->| GCC |--->phy_aux_clk---+
>>> + *    clk  |   +-------+   |                      +-----+
>>> + *         +---------------+
>>> + */
>>> +static int phy_aux_clk_register(struct qmp_pcie *qmp, struct device_node *np)
>>> +{
>>> +       struct clk_fixed_rate *fixed = &qmp->aux_clk_fixed;
>>> +       struct clk_init_data init = { };
>>> +       int ret;
>>> +
>>> +       ret = of_property_read_string_index(np, "clock-output-names", 1, &init.name);
>>> +       if (ret) {
>>> +               dev_err(qmp->dev, "%pOFn: No clock-output-names index 1\n", np);
>>> +               return ret;
>>> +       }
>>> +
>>> +       init.ops = &clk_fixed_rate_ops;
>>> +
>>> +       fixed->fixed_rate = qmp->cfg->aux_clock_rate;
>>> +       fixed->hw.init = &init;
>>> +
>>> +       return devm_clk_hw_register(qmp->dev, &fixed->hw);
>>> +}
>>> +
>>> +static struct clk_hw *qmp_pcie_clk_hw_get(struct of_phandle_args *clkspec, void *data)
>>> +{
>>> +       struct qmp_pcie *qmp = data;
>>> +
>>> +       /* Support legacy bindings */
>>> +       if (!clkspec->args_count)
>>> +               return &qmp->pipe_clk_fixed.hw;
>>> +
>>> +       switch (clkspec->args[0]) {
>>> +       case QMP_PCIE_PIPE_CLK:
>>> +               return &qmp->pipe_clk_fixed.hw;
>>> +       case QMP_PCIE_PHY_AUX_CLK:
>>> +               return &qmp->aux_clk_fixed.hw;
>>> +       }
>>> +
>>> +       return ERR_PTR(-EINVAL);
>>> +}
>>
>> Can we use of_clk_hw_onecell_get() instead? I think it even should be
>> possible to use onecell for both cases, it will look at the first arg,
>> which will be 0 in case of #clock-cells equal to 0.
> 
> Let me investigate if it's possible

Ok, it would work but it would require building a clk_hw_onecell_data a runtime,
while we could simply provide this qmp_pcie_clk_hw_get() and avoid runtime 2 allocations.

I'm not sure it's worth it.

Neil

> 
>>
>>> +
>>>   static int qmp_pcie_register_clocks(struct qmp_pcie *qmp, struct device_node *np)
>>>   {
>>>          int ret;
>>> @@ -3689,6 +3751,14 @@ static int qmp_pcie_register_clocks(struct qmp_pcie *qmp, struct device_node *np
>>>          if (ret)
>>>                  return ret;
>>>
>>> +       if (qmp->cfg->aux_clock_rate) {
>>> +               ret = phy_aux_clk_register(qmp, np);
>>> +               if (ret)
>>> +                       return ret;
>>> +
>>> +               return devm_of_clk_add_hw_provider(qmp->dev, qmp_pcie_clk_hw_get, qmp);
>>> +       }
>>> +
>>>          return devm_of_clk_add_hw_provider(qmp->dev, of_clk_hw_simple_get,
>>>                                             &qmp->pipe_clk_fixed.hw);
>>>   }
>>>
>>> -- 
>>> 2.34.1
>>>
>>>
>>
>>
>
Dmitry Baryshkov March 19, 2024, 2:46 p.m. UTC | #4
On Tue, 19 Mar 2024 at 16:35, Neil Armstrong <neil.armstrong@linaro.org> wrote:
>
> On 19/03/2024 11:59, Neil Armstrong wrote:
> > On 19/03/2024 11:55, Dmitry Baryshkov wrote:
> >> On Tue, 19 Mar 2024 at 12:45, Neil Armstrong <neil.armstrong@linaro.org> wrote:
> >>>
> >>> The PCIe Gen4x2 PHY found in the SM8[456]50 SoCs have a second clock,
> >>> add the code to register it for PHYs configs that sets a aux_clock_rate.
> >>>
> >>> In order to get the right clock, add qmp_pcie_clk_hw_get() which uses
> >>> the newly introduced QMP_PCIE_PIPE_CLK & QMP_PCIE_PHY_AUX_CLK clock
> >>> IDs and also supports the legacy bindings by returning the PIPE clock.
> >>>
> >>> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
> >>> ---
> >>>   drivers/phy/qualcomm/phy-qcom-qmp-pcie.c | 70 ++++++++++++++++++++++++++++++++
> >>>   1 file changed, 70 insertions(+)
> >>>
> >>> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
> >>> index 079b3e306489..2d05226ae200 100644
> >>> --- a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
> >>> +++ b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
> >>> @@ -22,6 +22,8 @@
> >>>   #include <linux/reset.h>
> >>>   #include <linux/slab.h>
> >>>
> >>> +#include <dt-bindings/phy/phy-qcom-qmp.h>
> >>> +
> >>>   #include "phy-qcom-qmp-common.h"
> >>>
> >>>   #include "phy-qcom-qmp.h"
> >>> @@ -2389,6 +2391,9 @@ struct qmp_phy_cfg {
> >>>
> >>>          /* QMP PHY pipe clock interface rate */
> >>>          unsigned long pipe_clock_rate;
> >>> +
> >>> +       /* QMP PHY AUX clock interface rate */
> >>> +       unsigned long aux_clock_rate;
> >>>   };
> >>>
> >>>   struct qmp_pcie {
> >>> @@ -2420,6 +2425,7 @@ struct qmp_pcie {
> >>>          int mode;
> >>>
> >>>          struct clk_fixed_rate pipe_clk_fixed;
> >>> +       struct clk_fixed_rate aux_clk_fixed;
> >>>   };
> >>>
> >>>   static inline void qphy_setbits(void __iomem *base, u32 offset, u32 val)
> >>> @@ -3681,6 +3687,62 @@ static int phy_pipe_clk_register(struct qmp_pcie *qmp, struct device_node *np)
> >>>          return devm_clk_hw_register(qmp->dev, &fixed->hw);
> >>>   }
> >>>
> >>> +/*
> >>> + * Register a fixed rate PHY aux clock.
> >>> + *
> >>> + * The <s>_phy_aux_clksrc generated by PHY goes to the GCC that gate
> >>> + * controls it. The <s>_phy_aux_clk coming out of the GCC is requested
> >>> + * by the PHY driver for its operations.
> >>> + * We register the <s>_phy_aux_clksrc here. The gcc driver takes care
> >>> + * of assigning this <s>_phy_aux_clksrc as parent to <s>_phy_aux_clk.
> >>> + * Below picture shows this relationship.
> >>> + *
> >>> + *         +---------------+
> >>> + *         |   PHY block   |<<---------------------------------------------+
> >>> + *         |               |                                               |
> >>> + *         |   +-------+   |                      +-----+                  |
> >>> + *   I/P---^-->|  PLL  |---^--->phy_aux_clksrc--->| GCC |--->phy_aux_clk---+
> >>> + *    clk  |   +-------+   |                      +-----+
> >>> + *         +---------------+
> >>> + */
> >>> +static int phy_aux_clk_register(struct qmp_pcie *qmp, struct device_node *np)
> >>> +{
> >>> +       struct clk_fixed_rate *fixed = &qmp->aux_clk_fixed;
> >>> +       struct clk_init_data init = { };
> >>> +       int ret;
> >>> +
> >>> +       ret = of_property_read_string_index(np, "clock-output-names", 1, &init.name);
> >>> +       if (ret) {
> >>> +               dev_err(qmp->dev, "%pOFn: No clock-output-names index 1\n", np);
> >>> +               return ret;
> >>> +       }
> >>> +
> >>> +       init.ops = &clk_fixed_rate_ops;
> >>> +
> >>> +       fixed->fixed_rate = qmp->cfg->aux_clock_rate;
> >>> +       fixed->hw.init = &init;
> >>> +
> >>> +       return devm_clk_hw_register(qmp->dev, &fixed->hw);
> >>> +}
> >>> +
> >>> +static struct clk_hw *qmp_pcie_clk_hw_get(struct of_phandle_args *clkspec, void *data)
> >>> +{
> >>> +       struct qmp_pcie *qmp = data;
> >>> +
> >>> +       /* Support legacy bindings */
> >>> +       if (!clkspec->args_count)
> >>> +               return &qmp->pipe_clk_fixed.hw;
> >>> +
> >>> +       switch (clkspec->args[0]) {
> >>> +       case QMP_PCIE_PIPE_CLK:
> >>> +               return &qmp->pipe_clk_fixed.hw;
> >>> +       case QMP_PCIE_PHY_AUX_CLK:
> >>> +               return &qmp->aux_clk_fixed.hw;
> >>> +       }
> >>> +
> >>> +       return ERR_PTR(-EINVAL);
> >>> +}
> >>
> >> Can we use of_clk_hw_onecell_get() instead? I think it even should be
> >> possible to use onecell for both cases, it will look at the first arg,
> >> which will be 0 in case of #clock-cells equal to 0.
> >
> > Let me investigate if it's possible
>
> Ok, it would work but it would require building a clk_hw_onecell_data a runtime,
> while we could simply provide this qmp_pcie_clk_hw_get() and avoid runtime 2 allocations.
>
> I'm not sure it's worth it.

Single allocation (or even 0 allocations if you embed it into struct
qmp_pcie) for the sake of using standard helpers.
Neil Armstrong March 19, 2024, 3:10 p.m. UTC | #5
On 19/03/2024 15:46, Dmitry Baryshkov wrote:
> On Tue, 19 Mar 2024 at 16:35, Neil Armstrong <neil.armstrong@linaro.org> wrote:
>>
>> On 19/03/2024 11:59, Neil Armstrong wrote:
>>> On 19/03/2024 11:55, Dmitry Baryshkov wrote:
>>>> On Tue, 19 Mar 2024 at 12:45, Neil Armstrong <neil.armstrong@linaro.org> wrote:
>>>>>
>>>>> The PCIe Gen4x2 PHY found in the SM8[456]50 SoCs have a second clock,
>>>>> add the code to register it for PHYs configs that sets a aux_clock_rate.
>>>>>
>>>>> In order to get the right clock, add qmp_pcie_clk_hw_get() which uses
>>>>> the newly introduced QMP_PCIE_PIPE_CLK & QMP_PCIE_PHY_AUX_CLK clock
>>>>> IDs and also supports the legacy bindings by returning the PIPE clock.
>>>>>
>>>>> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
>>>>> ---
>>>>>    drivers/phy/qualcomm/phy-qcom-qmp-pcie.c | 70 ++++++++++++++++++++++++++++++++
>>>>>    1 file changed, 70 insertions(+)
>>>>>
>>>>> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
>>>>> index 079b3e306489..2d05226ae200 100644
>>>>> --- a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
>>>>> +++ b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
>>>>> @@ -22,6 +22,8 @@
>>>>>    #include <linux/reset.h>
>>>>>    #include <linux/slab.h>
>>>>>
>>>>> +#include <dt-bindings/phy/phy-qcom-qmp.h>
>>>>> +
>>>>>    #include "phy-qcom-qmp-common.h"
>>>>>
>>>>>    #include "phy-qcom-qmp.h"
>>>>> @@ -2389,6 +2391,9 @@ struct qmp_phy_cfg {
>>>>>
>>>>>           /* QMP PHY pipe clock interface rate */
>>>>>           unsigned long pipe_clock_rate;
>>>>> +
>>>>> +       /* QMP PHY AUX clock interface rate */
>>>>> +       unsigned long aux_clock_rate;
>>>>>    };
>>>>>
>>>>>    struct qmp_pcie {
>>>>> @@ -2420,6 +2425,7 @@ struct qmp_pcie {
>>>>>           int mode;
>>>>>
>>>>>           struct clk_fixed_rate pipe_clk_fixed;
>>>>> +       struct clk_fixed_rate aux_clk_fixed;
>>>>>    };
>>>>>
>>>>>    static inline void qphy_setbits(void __iomem *base, u32 offset, u32 val)
>>>>> @@ -3681,6 +3687,62 @@ static int phy_pipe_clk_register(struct qmp_pcie *qmp, struct device_node *np)
>>>>>           return devm_clk_hw_register(qmp->dev, &fixed->hw);
>>>>>    }
>>>>>
>>>>> +/*
>>>>> + * Register a fixed rate PHY aux clock.
>>>>> + *
>>>>> + * The <s>_phy_aux_clksrc generated by PHY goes to the GCC that gate
>>>>> + * controls it. The <s>_phy_aux_clk coming out of the GCC is requested
>>>>> + * by the PHY driver for its operations.
>>>>> + * We register the <s>_phy_aux_clksrc here. The gcc driver takes care
>>>>> + * of assigning this <s>_phy_aux_clksrc as parent to <s>_phy_aux_clk.
>>>>> + * Below picture shows this relationship.
>>>>> + *
>>>>> + *         +---------------+
>>>>> + *         |   PHY block   |<<---------------------------------------------+
>>>>> + *         |               |                                               |
>>>>> + *         |   +-------+   |                      +-----+                  |
>>>>> + *   I/P---^-->|  PLL  |---^--->phy_aux_clksrc--->| GCC |--->phy_aux_clk---+
>>>>> + *    clk  |   +-------+   |                      +-----+
>>>>> + *         +---------------+
>>>>> + */
>>>>> +static int phy_aux_clk_register(struct qmp_pcie *qmp, struct device_node *np)
>>>>> +{
>>>>> +       struct clk_fixed_rate *fixed = &qmp->aux_clk_fixed;
>>>>> +       struct clk_init_data init = { };
>>>>> +       int ret;
>>>>> +
>>>>> +       ret = of_property_read_string_index(np, "clock-output-names", 1, &init.name);
>>>>> +       if (ret) {
>>>>> +               dev_err(qmp->dev, "%pOFn: No clock-output-names index 1\n", np);
>>>>> +               return ret;
>>>>> +       }
>>>>> +
>>>>> +       init.ops = &clk_fixed_rate_ops;
>>>>> +
>>>>> +       fixed->fixed_rate = qmp->cfg->aux_clock_rate;
>>>>> +       fixed->hw.init = &init;
>>>>> +
>>>>> +       return devm_clk_hw_register(qmp->dev, &fixed->hw);
>>>>> +}
>>>>> +
>>>>> +static struct clk_hw *qmp_pcie_clk_hw_get(struct of_phandle_args *clkspec, void *data)
>>>>> +{
>>>>> +       struct qmp_pcie *qmp = data;
>>>>> +
>>>>> +       /* Support legacy bindings */
>>>>> +       if (!clkspec->args_count)
>>>>> +               return &qmp->pipe_clk_fixed.hw;
>>>>> +
>>>>> +       switch (clkspec->args[0]) {
>>>>> +       case QMP_PCIE_PIPE_CLK:
>>>>> +               return &qmp->pipe_clk_fixed.hw;
>>>>> +       case QMP_PCIE_PHY_AUX_CLK:
>>>>> +               return &qmp->aux_clk_fixed.hw;
>>>>> +       }
>>>>> +
>>>>> +       return ERR_PTR(-EINVAL);
>>>>> +}
>>>>
>>>> Can we use of_clk_hw_onecell_get() instead? I think it even should be
>>>> possible to use onecell for both cases, it will look at the first arg,
>>>> which will be 0 in case of #clock-cells equal to 0.

I didn't find evidence this is the case, while following of_parse_clkspec() called
from of_clk_get_hw() or clk_core_get(), where clkspec is not initialized, the
__of_parse_phandle_with_args() and of_phandle_iterator_args() don't touch
clkspec->args if it->cur_count is 0. So clkspec->args[0] may be left initialized
and it would be abusingthe API to use it with #clocks-cells = 0.

>>>
>>> Let me investigate if it's possible
>>
>> Ok, it would work but it would require building a clk_hw_onecell_data a runtime,
>> while we could simply provide this qmp_pcie_clk_hw_get() and avoid runtime 2 allocations.
>>
>> I'm not sure it's worth it.
> 
> Single allocation (or even 0 allocations if you embed it into struct
> qmp_pcie) for the sake of using standard helpers.
> 
Well, sure

Thanks,
Neil
Dmitry Baryshkov March 19, 2024, 3:14 p.m. UTC | #6
On Tue, 19 Mar 2024 at 17:10, <neil.armstrong@linaro.org> wrote:
>
> On 19/03/2024 15:46, Dmitry Baryshkov wrote:
> > On Tue, 19 Mar 2024 at 16:35, Neil Armstrong <neil.armstrong@linaro.org> wrote:
> >>
> >> On 19/03/2024 11:59, Neil Armstrong wrote:
> >>> On 19/03/2024 11:55, Dmitry Baryshkov wrote:
> >>>> On Tue, 19 Mar 2024 at 12:45, Neil Armstrong <neil.armstrong@linaro.org> wrote:
> >>>>>
> >>>>> The PCIe Gen4x2 PHY found in the SM8[456]50 SoCs have a second clock,
> >>>>> add the code to register it for PHYs configs that sets a aux_clock_rate.
> >>>>>
> >>>>> In order to get the right clock, add qmp_pcie_clk_hw_get() which uses
> >>>>> the newly introduced QMP_PCIE_PIPE_CLK & QMP_PCIE_PHY_AUX_CLK clock
> >>>>> IDs and also supports the legacy bindings by returning the PIPE clock.
> >>>>>
> >>>>> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
> >>>>> ---
> >>>>>    drivers/phy/qualcomm/phy-qcom-qmp-pcie.c | 70 ++++++++++++++++++++++++++++++++
> >>>>>    1 file changed, 70 insertions(+)
> >>>>>
> >>>>> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
> >>>>> index 079b3e306489..2d05226ae200 100644
> >>>>> --- a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
> >>>>> +++ b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
> >>>>> @@ -22,6 +22,8 @@
> >>>>>    #include <linux/reset.h>
> >>>>>    #include <linux/slab.h>
> >>>>>
> >>>>> +#include <dt-bindings/phy/phy-qcom-qmp.h>
> >>>>> +
> >>>>>    #include "phy-qcom-qmp-common.h"
> >>>>>
> >>>>>    #include "phy-qcom-qmp.h"
> >>>>> @@ -2389,6 +2391,9 @@ struct qmp_phy_cfg {
> >>>>>
> >>>>>           /* QMP PHY pipe clock interface rate */
> >>>>>           unsigned long pipe_clock_rate;
> >>>>> +
> >>>>> +       /* QMP PHY AUX clock interface rate */
> >>>>> +       unsigned long aux_clock_rate;
> >>>>>    };
> >>>>>
> >>>>>    struct qmp_pcie {
> >>>>> @@ -2420,6 +2425,7 @@ struct qmp_pcie {
> >>>>>           int mode;
> >>>>>
> >>>>>           struct clk_fixed_rate pipe_clk_fixed;
> >>>>> +       struct clk_fixed_rate aux_clk_fixed;
> >>>>>    };
> >>>>>
> >>>>>    static inline void qphy_setbits(void __iomem *base, u32 offset, u32 val)
> >>>>> @@ -3681,6 +3687,62 @@ static int phy_pipe_clk_register(struct qmp_pcie *qmp, struct device_node *np)
> >>>>>           return devm_clk_hw_register(qmp->dev, &fixed->hw);
> >>>>>    }
> >>>>>
> >>>>> +/*
> >>>>> + * Register a fixed rate PHY aux clock.
> >>>>> + *
> >>>>> + * The <s>_phy_aux_clksrc generated by PHY goes to the GCC that gate
> >>>>> + * controls it. The <s>_phy_aux_clk coming out of the GCC is requested
> >>>>> + * by the PHY driver for its operations.
> >>>>> + * We register the <s>_phy_aux_clksrc here. The gcc driver takes care
> >>>>> + * of assigning this <s>_phy_aux_clksrc as parent to <s>_phy_aux_clk.
> >>>>> + * Below picture shows this relationship.
> >>>>> + *
> >>>>> + *         +---------------+
> >>>>> + *         |   PHY block   |<<---------------------------------------------+
> >>>>> + *         |               |                                               |
> >>>>> + *         |   +-------+   |                      +-----+                  |
> >>>>> + *   I/P---^-->|  PLL  |---^--->phy_aux_clksrc--->| GCC |--->phy_aux_clk---+
> >>>>> + *    clk  |   +-------+   |                      +-----+
> >>>>> + *         +---------------+
> >>>>> + */
> >>>>> +static int phy_aux_clk_register(struct qmp_pcie *qmp, struct device_node *np)
> >>>>> +{
> >>>>> +       struct clk_fixed_rate *fixed = &qmp->aux_clk_fixed;
> >>>>> +       struct clk_init_data init = { };
> >>>>> +       int ret;
> >>>>> +
> >>>>> +       ret = of_property_read_string_index(np, "clock-output-names", 1, &init.name);
> >>>>> +       if (ret) {
> >>>>> +               dev_err(qmp->dev, "%pOFn: No clock-output-names index 1\n", np);
> >>>>> +               return ret;
> >>>>> +       }
> >>>>> +
> >>>>> +       init.ops = &clk_fixed_rate_ops;
> >>>>> +
> >>>>> +       fixed->fixed_rate = qmp->cfg->aux_clock_rate;
> >>>>> +       fixed->hw.init = &init;
> >>>>> +
> >>>>> +       return devm_clk_hw_register(qmp->dev, &fixed->hw);
> >>>>> +}
> >>>>> +
> >>>>> +static struct clk_hw *qmp_pcie_clk_hw_get(struct of_phandle_args *clkspec, void *data)
> >>>>> +{
> >>>>> +       struct qmp_pcie *qmp = data;
> >>>>> +
> >>>>> +       /* Support legacy bindings */
> >>>>> +       if (!clkspec->args_count)
> >>>>> +               return &qmp->pipe_clk_fixed.hw;
> >>>>> +
> >>>>> +       switch (clkspec->args[0]) {
> >>>>> +       case QMP_PCIE_PIPE_CLK:
> >>>>> +               return &qmp->pipe_clk_fixed.hw;
> >>>>> +       case QMP_PCIE_PHY_AUX_CLK:
> >>>>> +               return &qmp->aux_clk_fixed.hw;
> >>>>> +       }
> >>>>> +
> >>>>> +       return ERR_PTR(-EINVAL);
> >>>>> +}
> >>>>
> >>>> Can we use of_clk_hw_onecell_get() instead? I think it even should be
> >>>> possible to use onecell for both cases, it will look at the first arg,
> >>>> which will be 0 in case of #clock-cells equal to 0.
>
> I didn't find evidence this is the case, while following of_parse_clkspec() called
> from of_clk_get_hw() or clk_core_get(), where clkspec is not initialized, the
> __of_parse_phandle_with_args() and of_phandle_iterator_args() don't touch
> clkspec->args if it->cur_count is 0. So clkspec->args[0] may be left initialized
> and it would be abusingthe API to use it with #clocks-cells = 0.

Ack, true.

>
> >>>
> >>> Let me investigate if it's possible
> >>
> >> Ok, it would work but it would require building a clk_hw_onecell_data a runtime,
> >> while we could simply provide this qmp_pcie_clk_hw_get() and avoid runtime 2 allocations.
> >>
> >> I'm not sure it's worth it.
> >
> > Single allocation (or even 0 allocations if you embed it into struct
> > qmp_pcie) for the sake of using standard helpers.
> >
> Well, sure
>
> Thanks,
> Neil
>
Neil Armstrong March 19, 2024, 3:15 p.m. UTC | #7
On 19/03/2024 15:46, Dmitry Baryshkov wrote:
> On Tue, 19 Mar 2024 at 16:35, Neil Armstrong <neil.armstrong@linaro.org> wrote:
>>
>> On 19/03/2024 11:59, Neil Armstrong wrote:
>>> On 19/03/2024 11:55, Dmitry Baryshkov wrote:
>>>> On Tue, 19 Mar 2024 at 12:45, Neil Armstrong <neil.armstrong@linaro.org> wrote:
>>>>>
>>>>> The PCIe Gen4x2 PHY found in the SM8[456]50 SoCs have a second clock,
>>>>> add the code to register it for PHYs configs that sets a aux_clock_rate.
>>>>>
>>>>> In order to get the right clock, add qmp_pcie_clk_hw_get() which uses
>>>>> the newly introduced QMP_PCIE_PIPE_CLK & QMP_PCIE_PHY_AUX_CLK clock
>>>>> IDs and also supports the legacy bindings by returning the PIPE clock.
>>>>>
>>>>> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
>>>>> ---
>>>>>    drivers/phy/qualcomm/phy-qcom-qmp-pcie.c | 70 ++++++++++++++++++++++++++++++++
>>>>>    1 file changed, 70 insertions(+)
>>>>>
>>>>> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
>>>>> index 079b3e306489..2d05226ae200 100644
>>>>> --- a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
>>>>> +++ b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
>>>>> @@ -22,6 +22,8 @@
>>>>>    #include <linux/reset.h>
>>>>>    #include <linux/slab.h>
>>>>>
>>>>> +#include <dt-bindings/phy/phy-qcom-qmp.h>
>>>>> +
>>>>>    #include "phy-qcom-qmp-common.h"
>>>>>
>>>>>    #include "phy-qcom-qmp.h"
>>>>> @@ -2389,6 +2391,9 @@ struct qmp_phy_cfg {
>>>>>
>>>>>           /* QMP PHY pipe clock interface rate */
>>>>>           unsigned long pipe_clock_rate;
>>>>> +
>>>>> +       /* QMP PHY AUX clock interface rate */
>>>>> +       unsigned long aux_clock_rate;
>>>>>    };
>>>>>
>>>>>    struct qmp_pcie {
>>>>> @@ -2420,6 +2425,7 @@ struct qmp_pcie {
>>>>>           int mode;
>>>>>
>>>>>           struct clk_fixed_rate pipe_clk_fixed;
>>>>> +       struct clk_fixed_rate aux_clk_fixed;
>>>>>    };
>>>>>
>>>>>    static inline void qphy_setbits(void __iomem *base, u32 offset, u32 val)
>>>>> @@ -3681,6 +3687,62 @@ static int phy_pipe_clk_register(struct qmp_pcie *qmp, struct device_node *np)
>>>>>           return devm_clk_hw_register(qmp->dev, &fixed->hw);
>>>>>    }
>>>>>
>>>>> +/*
>>>>> + * Register a fixed rate PHY aux clock.
>>>>> + *
>>>>> + * The <s>_phy_aux_clksrc generated by PHY goes to the GCC that gate
>>>>> + * controls it. The <s>_phy_aux_clk coming out of the GCC is requested
>>>>> + * by the PHY driver for its operations.
>>>>> + * We register the <s>_phy_aux_clksrc here. The gcc driver takes care
>>>>> + * of assigning this <s>_phy_aux_clksrc as parent to <s>_phy_aux_clk.
>>>>> + * Below picture shows this relationship.
>>>>> + *
>>>>> + *         +---------------+
>>>>> + *         |   PHY block   |<<---------------------------------------------+
>>>>> + *         |               |                                               |
>>>>> + *         |   +-------+   |                      +-----+                  |
>>>>> + *   I/P---^-->|  PLL  |---^--->phy_aux_clksrc--->| GCC |--->phy_aux_clk---+
>>>>> + *    clk  |   +-------+   |                      +-----+
>>>>> + *         +---------------+
>>>>> + */
>>>>> +static int phy_aux_clk_register(struct qmp_pcie *qmp, struct device_node *np)
>>>>> +{
>>>>> +       struct clk_fixed_rate *fixed = &qmp->aux_clk_fixed;
>>>>> +       struct clk_init_data init = { };
>>>>> +       int ret;
>>>>> +
>>>>> +       ret = of_property_read_string_index(np, "clock-output-names", 1, &init.name);
>>>>> +       if (ret) {
>>>>> +               dev_err(qmp->dev, "%pOFn: No clock-output-names index 1\n", np);
>>>>> +               return ret;
>>>>> +       }
>>>>> +
>>>>> +       init.ops = &clk_fixed_rate_ops;
>>>>> +
>>>>> +       fixed->fixed_rate = qmp->cfg->aux_clock_rate;
>>>>> +       fixed->hw.init = &init;
>>>>> +
>>>>> +       return devm_clk_hw_register(qmp->dev, &fixed->hw);
>>>>> +}
>>>>> +
>>>>> +static struct clk_hw *qmp_pcie_clk_hw_get(struct of_phandle_args *clkspec, void *data)
>>>>> +{
>>>>> +       struct qmp_pcie *qmp = data;
>>>>> +
>>>>> +       /* Support legacy bindings */
>>>>> +       if (!clkspec->args_count)
>>>>> +               return &qmp->pipe_clk_fixed.hw;
>>>>> +
>>>>> +       switch (clkspec->args[0]) {
>>>>> +       case QMP_PCIE_PIPE_CLK:
>>>>> +               return &qmp->pipe_clk_fixed.hw;
>>>>> +       case QMP_PCIE_PHY_AUX_CLK:
>>>>> +               return &qmp->aux_clk_fixed.hw;
>>>>> +       }
>>>>> +
>>>>> +       return ERR_PTR(-EINVAL);
>>>>> +}
>>>>
>>>> Can we use of_clk_hw_onecell_get() instead? I think it even should be
>>>> possible to use onecell for both cases, it will look at the first arg,
>>>> which will be 0 in case of #clock-cells equal to 0.
>>>
>>> Let me investigate if it's possible
>>
>> Ok, it would work but it would require building a clk_hw_onecell_data a runtime,
>> while we could simply provide this qmp_pcie_clk_hw_get() and avoid runtime 2 allocations.
>>
>> I'm not sure it's worth it.
> 
> Single allocation (or even 0 allocations if you embed it into struct
> qmp_pcie) for the sake of using standard helpers.

And I just recall I tried the same for Amlogic clocks, but the clk_hw_onecell_data hws
field is a flexible array member you can't set at runtime, if you try you'll get:
drivers/phy/qualcomm/phy-qcom-qmp-pcie.c:3753:38: error: invalid use of flexible array member
  3753 |                 qmp->clk_hw_data.hws = qmp->clk_hws;

Neil

> 
> 
>
Dmitry Baryshkov March 19, 2024, 4:05 p.m. UTC | #8
On Tue, 19 Mar 2024 at 17:15, <neil.armstrong@linaro.org> wrote:
>
> On 19/03/2024 15:46, Dmitry Baryshkov wrote:
> > On Tue, 19 Mar 2024 at 16:35, Neil Armstrong <neil.armstrong@linaro.org> wrote:
> >>
> >> On 19/03/2024 11:59, Neil Armstrong wrote:
> >>> On 19/03/2024 11:55, Dmitry Baryshkov wrote:
> >>>> On Tue, 19 Mar 2024 at 12:45, Neil Armstrong <neil.armstrong@linaro.org> wrote:
> >>>>>
> >>>>> The PCIe Gen4x2 PHY found in the SM8[456]50 SoCs have a second clock,
> >>>>> add the code to register it for PHYs configs that sets a aux_clock_rate.
> >>>>>
> >>>>> In order to get the right clock, add qmp_pcie_clk_hw_get() which uses
> >>>>> the newly introduced QMP_PCIE_PIPE_CLK & QMP_PCIE_PHY_AUX_CLK clock
> >>>>> IDs and also supports the legacy bindings by returning the PIPE clock.
> >>>>>
> >>>>> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
> >>>>> ---
> >>>>>    drivers/phy/qualcomm/phy-qcom-qmp-pcie.c | 70 ++++++++++++++++++++++++++++++++
> >>>>>    1 file changed, 70 insertions(+)
> >>>>>
> >>>>> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
> >>>>> index 079b3e306489..2d05226ae200 100644
> >>>>> --- a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
> >>>>> +++ b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
> >>>>> @@ -22,6 +22,8 @@
> >>>>>    #include <linux/reset.h>
> >>>>>    #include <linux/slab.h>
> >>>>>
> >>>>> +#include <dt-bindings/phy/phy-qcom-qmp.h>
> >>>>> +
> >>>>>    #include "phy-qcom-qmp-common.h"
> >>>>>
> >>>>>    #include "phy-qcom-qmp.h"
> >>>>> @@ -2389,6 +2391,9 @@ struct qmp_phy_cfg {
> >>>>>
> >>>>>           /* QMP PHY pipe clock interface rate */
> >>>>>           unsigned long pipe_clock_rate;
> >>>>> +
> >>>>> +       /* QMP PHY AUX clock interface rate */
> >>>>> +       unsigned long aux_clock_rate;
> >>>>>    };
> >>>>>
> >>>>>    struct qmp_pcie {
> >>>>> @@ -2420,6 +2425,7 @@ struct qmp_pcie {
> >>>>>           int mode;
> >>>>>
> >>>>>           struct clk_fixed_rate pipe_clk_fixed;
> >>>>> +       struct clk_fixed_rate aux_clk_fixed;
> >>>>>    };
> >>>>>
> >>>>>    static inline void qphy_setbits(void __iomem *base, u32 offset, u32 val)
> >>>>> @@ -3681,6 +3687,62 @@ static int phy_pipe_clk_register(struct qmp_pcie *qmp, struct device_node *np)
> >>>>>           return devm_clk_hw_register(qmp->dev, &fixed->hw);
> >>>>>    }
> >>>>>
> >>>>> +/*
> >>>>> + * Register a fixed rate PHY aux clock.
> >>>>> + *
> >>>>> + * The <s>_phy_aux_clksrc generated by PHY goes to the GCC that gate
> >>>>> + * controls it. The <s>_phy_aux_clk coming out of the GCC is requested
> >>>>> + * by the PHY driver for its operations.
> >>>>> + * We register the <s>_phy_aux_clksrc here. The gcc driver takes care
> >>>>> + * of assigning this <s>_phy_aux_clksrc as parent to <s>_phy_aux_clk.
> >>>>> + * Below picture shows this relationship.
> >>>>> + *
> >>>>> + *         +---------------+
> >>>>> + *         |   PHY block   |<<---------------------------------------------+
> >>>>> + *         |               |                                               |
> >>>>> + *         |   +-------+   |                      +-----+                  |
> >>>>> + *   I/P---^-->|  PLL  |---^--->phy_aux_clksrc--->| GCC |--->phy_aux_clk---+
> >>>>> + *    clk  |   +-------+   |                      +-----+
> >>>>> + *         +---------------+
> >>>>> + */
> >>>>> +static int phy_aux_clk_register(struct qmp_pcie *qmp, struct device_node *np)
> >>>>> +{
> >>>>> +       struct clk_fixed_rate *fixed = &qmp->aux_clk_fixed;
> >>>>> +       struct clk_init_data init = { };
> >>>>> +       int ret;
> >>>>> +
> >>>>> +       ret = of_property_read_string_index(np, "clock-output-names", 1, &init.name);
> >>>>> +       if (ret) {
> >>>>> +               dev_err(qmp->dev, "%pOFn: No clock-output-names index 1\n", np);
> >>>>> +               return ret;
> >>>>> +       }
> >>>>> +
> >>>>> +       init.ops = &clk_fixed_rate_ops;
> >>>>> +
> >>>>> +       fixed->fixed_rate = qmp->cfg->aux_clock_rate;
> >>>>> +       fixed->hw.init = &init;
> >>>>> +
> >>>>> +       return devm_clk_hw_register(qmp->dev, &fixed->hw);
> >>>>> +}
> >>>>> +
> >>>>> +static struct clk_hw *qmp_pcie_clk_hw_get(struct of_phandle_args *clkspec, void *data)
> >>>>> +{
> >>>>> +       struct qmp_pcie *qmp = data;
> >>>>> +
> >>>>> +       /* Support legacy bindings */
> >>>>> +       if (!clkspec->args_count)
> >>>>> +               return &qmp->pipe_clk_fixed.hw;
> >>>>> +
> >>>>> +       switch (clkspec->args[0]) {
> >>>>> +       case QMP_PCIE_PIPE_CLK:
> >>>>> +               return &qmp->pipe_clk_fixed.hw;
> >>>>> +       case QMP_PCIE_PHY_AUX_CLK:
> >>>>> +               return &qmp->aux_clk_fixed.hw;
> >>>>> +       }
> >>>>> +
> >>>>> +       return ERR_PTR(-EINVAL);
> >>>>> +}
> >>>>
> >>>> Can we use of_clk_hw_onecell_get() instead? I think it even should be
> >>>> possible to use onecell for both cases, it will look at the first arg,
> >>>> which will be 0 in case of #clock-cells equal to 0.
> >>>
> >>> Let me investigate if it's possible
> >>
> >> Ok, it would work but it would require building a clk_hw_onecell_data a runtime,
> >> while we could simply provide this qmp_pcie_clk_hw_get() and avoid runtime 2 allocations.
> >>
> >> I'm not sure it's worth it.
> >
> > Single allocation (or even 0 allocations if you embed it into struct
> > qmp_pcie) for the sake of using standard helpers.
>
> And I just recall I tried the same for Amlogic clocks, but the clk_hw_onecell_data hws
> field is a flexible array member you can't set at runtime, if you try you'll get:
> drivers/phy/qualcomm/phy-qcom-qmp-pcie.c:3753:38: error: invalid use of flexible array member
>   3753 |                 qmp->clk_hw_data.hws = qmp->clk_hws;

Yes, so it's either
devm_kzalloc(dev, struct_size(data, hws, 2), GFP_KERNEL);
or
struct qmp_pcie {
...
  struct {
    struct clk_hw_onecell_data clk_data;
    struct clk_hw clocks[2];
  };
};

>
> Neil
>
> >
> >
> >
>
Neil Armstrong March 19, 2024, 4:45 p.m. UTC | #9
On 19/03/2024 17:05, Dmitry Baryshkov wrote:
> On Tue, 19 Mar 2024 at 17:15, <neil.armstrong@linaro.org> wrote:
>>
>> On 19/03/2024 15:46, Dmitry Baryshkov wrote:
>>> On Tue, 19 Mar 2024 at 16:35, Neil Armstrong <neil.armstrong@linaro.org> wrote:
>>>>
>>>> On 19/03/2024 11:59, Neil Armstrong wrote:
>>>>> On 19/03/2024 11:55, Dmitry Baryshkov wrote:
>>>>>> On Tue, 19 Mar 2024 at 12:45, Neil Armstrong <neil.armstrong@linaro.org> wrote:
>>>>>>>
>>>>>>> The PCIe Gen4x2 PHY found in the SM8[456]50 SoCs have a second clock,
>>>>>>> add the code to register it for PHYs configs that sets a aux_clock_rate.
>>>>>>>
>>>>>>> In order to get the right clock, add qmp_pcie_clk_hw_get() which uses
>>>>>>> the newly introduced QMP_PCIE_PIPE_CLK & QMP_PCIE_PHY_AUX_CLK clock
>>>>>>> IDs and also supports the legacy bindings by returning the PIPE clock.
>>>>>>>
>>>>>>> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
>>>>>>> ---
>>>>>>>     drivers/phy/qualcomm/phy-qcom-qmp-pcie.c | 70 ++++++++++++++++++++++++++++++++
>>>>>>>     1 file changed, 70 insertions(+)
>>>>>>>
>>>>>>> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
>>>>>>> index 079b3e306489..2d05226ae200 100644
>>>>>>> --- a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
>>>>>>> +++ b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
>>>>>>> @@ -22,6 +22,8 @@
>>>>>>>     #include <linux/reset.h>
>>>>>>>     #include <linux/slab.h>
>>>>>>>
>>>>>>> +#include <dt-bindings/phy/phy-qcom-qmp.h>
>>>>>>> +
>>>>>>>     #include "phy-qcom-qmp-common.h"
>>>>>>>
>>>>>>>     #include "phy-qcom-qmp.h"
>>>>>>> @@ -2389,6 +2391,9 @@ struct qmp_phy_cfg {
>>>>>>>
>>>>>>>            /* QMP PHY pipe clock interface rate */
>>>>>>>            unsigned long pipe_clock_rate;
>>>>>>> +
>>>>>>> +       /* QMP PHY AUX clock interface rate */
>>>>>>> +       unsigned long aux_clock_rate;
>>>>>>>     };
>>>>>>>
>>>>>>>     struct qmp_pcie {
>>>>>>> @@ -2420,6 +2425,7 @@ struct qmp_pcie {
>>>>>>>            int mode;
>>>>>>>
>>>>>>>            struct clk_fixed_rate pipe_clk_fixed;
>>>>>>> +       struct clk_fixed_rate aux_clk_fixed;
>>>>>>>     };
>>>>>>>
>>>>>>>     static inline void qphy_setbits(void __iomem *base, u32 offset, u32 val)
>>>>>>> @@ -3681,6 +3687,62 @@ static int phy_pipe_clk_register(struct qmp_pcie *qmp, struct device_node *np)
>>>>>>>            return devm_clk_hw_register(qmp->dev, &fixed->hw);
>>>>>>>     }
>>>>>>>
>>>>>>> +/*
>>>>>>> + * Register a fixed rate PHY aux clock.
>>>>>>> + *
>>>>>>> + * The <s>_phy_aux_clksrc generated by PHY goes to the GCC that gate
>>>>>>> + * controls it. The <s>_phy_aux_clk coming out of the GCC is requested
>>>>>>> + * by the PHY driver for its operations.
>>>>>>> + * We register the <s>_phy_aux_clksrc here. The gcc driver takes care
>>>>>>> + * of assigning this <s>_phy_aux_clksrc as parent to <s>_phy_aux_clk.
>>>>>>> + * Below picture shows this relationship.
>>>>>>> + *
>>>>>>> + *         +---------------+
>>>>>>> + *         |   PHY block   |<<---------------------------------------------+
>>>>>>> + *         |               |                                               |
>>>>>>> + *         |   +-------+   |                      +-----+                  |
>>>>>>> + *   I/P---^-->|  PLL  |---^--->phy_aux_clksrc--->| GCC |--->phy_aux_clk---+
>>>>>>> + *    clk  |   +-------+   |                      +-----+
>>>>>>> + *         +---------------+
>>>>>>> + */
>>>>>>> +static int phy_aux_clk_register(struct qmp_pcie *qmp, struct device_node *np)
>>>>>>> +{
>>>>>>> +       struct clk_fixed_rate *fixed = &qmp->aux_clk_fixed;
>>>>>>> +       struct clk_init_data init = { };
>>>>>>> +       int ret;
>>>>>>> +
>>>>>>> +       ret = of_property_read_string_index(np, "clock-output-names", 1, &init.name);
>>>>>>> +       if (ret) {
>>>>>>> +               dev_err(qmp->dev, "%pOFn: No clock-output-names index 1\n", np);
>>>>>>> +               return ret;
>>>>>>> +       }
>>>>>>> +
>>>>>>> +       init.ops = &clk_fixed_rate_ops;
>>>>>>> +
>>>>>>> +       fixed->fixed_rate = qmp->cfg->aux_clock_rate;
>>>>>>> +       fixed->hw.init = &init;
>>>>>>> +
>>>>>>> +       return devm_clk_hw_register(qmp->dev, &fixed->hw);
>>>>>>> +}
>>>>>>> +
>>>>>>> +static struct clk_hw *qmp_pcie_clk_hw_get(struct of_phandle_args *clkspec, void *data)
>>>>>>> +{
>>>>>>> +       struct qmp_pcie *qmp = data;
>>>>>>> +
>>>>>>> +       /* Support legacy bindings */
>>>>>>> +       if (!clkspec->args_count)
>>>>>>> +               return &qmp->pipe_clk_fixed.hw;
>>>>>>> +
>>>>>>> +       switch (clkspec->args[0]) {
>>>>>>> +       case QMP_PCIE_PIPE_CLK:
>>>>>>> +               return &qmp->pipe_clk_fixed.hw;
>>>>>>> +       case QMP_PCIE_PHY_AUX_CLK:
>>>>>>> +               return &qmp->aux_clk_fixed.hw;
>>>>>>> +       }
>>>>>>> +
>>>>>>> +       return ERR_PTR(-EINVAL);
>>>>>>> +}
>>>>>>
>>>>>> Can we use of_clk_hw_onecell_get() instead? I think it even should be
>>>>>> possible to use onecell for both cases, it will look at the first arg,
>>>>>> which will be 0 in case of #clock-cells equal to 0.
>>>>>
>>>>> Let me investigate if it's possible
>>>>
>>>> Ok, it would work but it would require building a clk_hw_onecell_data a runtime,
>>>> while we could simply provide this qmp_pcie_clk_hw_get() and avoid runtime 2 allocations.
>>>>
>>>> I'm not sure it's worth it.
>>>
>>> Single allocation (or even 0 allocations if you embed it into struct
>>> qmp_pcie) for the sake of using standard helpers.
>>
>> And I just recall I tried the same for Amlogic clocks, but the clk_hw_onecell_data hws
>> field is a flexible array member you can't set at runtime, if you try you'll get:
>> drivers/phy/qualcomm/phy-qcom-qmp-pcie.c:3753:38: error: invalid use of flexible array member
>>    3753 |                 qmp->clk_hw_data.hws = qmp->clk_hws;
> 
> Yes, so it's either
> devm_kzalloc(dev, struct_size(data, hws, 2), GFP_KERNEL);
> or
> struct qmp_pcie {
> ...
>    struct {
>      struct clk_hw_onecell_data clk_data;
>      struct clk_hw clocks[2];
>    };
> };

I won't go down this path because of that mess and using of_clk_hw_onecell_get() would need
to still add a custom getter before calling of_clk_hw_onecell_get() to handle the
#clock-cells=0 legacy case.

Neil

> 
>>
>> Neil
>>
>>>
>>>
>>>
>>
> 
>
Dmitry Baryshkov March 19, 2024, 4:56 p.m. UTC | #10
On Tue, 19 Mar 2024 at 18:46, <neil.armstrong@linaro.org> wrote:
>
> On 19/03/2024 17:05, Dmitry Baryshkov wrote:
> > On Tue, 19 Mar 2024 at 17:15, <neil.armstrong@linaro.org> wrote:
> >>
> >> On 19/03/2024 15:46, Dmitry Baryshkov wrote:
> >>> On Tue, 19 Mar 2024 at 16:35, Neil Armstrong <neil.armstrong@linaro.org> wrote:
> >>>>
> >>>> On 19/03/2024 11:59, Neil Armstrong wrote:
> >>>>> On 19/03/2024 11:55, Dmitry Baryshkov wrote:
> >>>>>> On Tue, 19 Mar 2024 at 12:45, Neil Armstrong <neil.armstrong@linaro.org> wrote:
> >>>>>>>
> >>>>>>> The PCIe Gen4x2 PHY found in the SM8[456]50 SoCs have a second clock,
> >>>>>>> add the code to register it for PHYs configs that sets a aux_clock_rate.
> >>>>>>>
> >>>>>>> In order to get the right clock, add qmp_pcie_clk_hw_get() which uses
> >>>>>>> the newly introduced QMP_PCIE_PIPE_CLK & QMP_PCIE_PHY_AUX_CLK clock
> >>>>>>> IDs and also supports the legacy bindings by returning the PIPE clock.
> >>>>>>>
> >>>>>>> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
> >>>>>>> ---
> >>>>>>>     drivers/phy/qualcomm/phy-qcom-qmp-pcie.c | 70 ++++++++++++++++++++++++++++++++
> >>>>>>>     1 file changed, 70 insertions(+)
> >>>>>>>
> >>>>>>> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
> >>>>>>> index 079b3e306489..2d05226ae200 100644
> >>>>>>> --- a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
> >>>>>>> +++ b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
> >>>>>>> @@ -22,6 +22,8 @@
> >>>>>>>     #include <linux/reset.h>
> >>>>>>>     #include <linux/slab.h>
> >>>>>>>
> >>>>>>> +#include <dt-bindings/phy/phy-qcom-qmp.h>
> >>>>>>> +
> >>>>>>>     #include "phy-qcom-qmp-common.h"
> >>>>>>>
> >>>>>>>     #include "phy-qcom-qmp.h"
> >>>>>>> @@ -2389,6 +2391,9 @@ struct qmp_phy_cfg {
> >>>>>>>
> >>>>>>>            /* QMP PHY pipe clock interface rate */
> >>>>>>>            unsigned long pipe_clock_rate;
> >>>>>>> +
> >>>>>>> +       /* QMP PHY AUX clock interface rate */
> >>>>>>> +       unsigned long aux_clock_rate;
> >>>>>>>     };
> >>>>>>>
> >>>>>>>     struct qmp_pcie {
> >>>>>>> @@ -2420,6 +2425,7 @@ struct qmp_pcie {
> >>>>>>>            int mode;
> >>>>>>>
> >>>>>>>            struct clk_fixed_rate pipe_clk_fixed;
> >>>>>>> +       struct clk_fixed_rate aux_clk_fixed;
> >>>>>>>     };
> >>>>>>>
> >>>>>>>     static inline void qphy_setbits(void __iomem *base, u32 offset, u32 val)
> >>>>>>> @@ -3681,6 +3687,62 @@ static int phy_pipe_clk_register(struct qmp_pcie *qmp, struct device_node *np)
> >>>>>>>            return devm_clk_hw_register(qmp->dev, &fixed->hw);
> >>>>>>>     }
> >>>>>>>
> >>>>>>> +/*
> >>>>>>> + * Register a fixed rate PHY aux clock.
> >>>>>>> + *
> >>>>>>> + * The <s>_phy_aux_clksrc generated by PHY goes to the GCC that gate
> >>>>>>> + * controls it. The <s>_phy_aux_clk coming out of the GCC is requested
> >>>>>>> + * by the PHY driver for its operations.
> >>>>>>> + * We register the <s>_phy_aux_clksrc here. The gcc driver takes care
> >>>>>>> + * of assigning this <s>_phy_aux_clksrc as parent to <s>_phy_aux_clk.
> >>>>>>> + * Below picture shows this relationship.
> >>>>>>> + *
> >>>>>>> + *         +---------------+
> >>>>>>> + *         |   PHY block   |<<---------------------------------------------+
> >>>>>>> + *         |               |                                               |
> >>>>>>> + *         |   +-------+   |                      +-----+                  |
> >>>>>>> + *   I/P---^-->|  PLL  |---^--->phy_aux_clksrc--->| GCC |--->phy_aux_clk---+
> >>>>>>> + *    clk  |   +-------+   |                      +-----+
> >>>>>>> + *         +---------------+
> >>>>>>> + */
> >>>>>>> +static int phy_aux_clk_register(struct qmp_pcie *qmp, struct device_node *np)
> >>>>>>> +{
> >>>>>>> +       struct clk_fixed_rate *fixed = &qmp->aux_clk_fixed;
> >>>>>>> +       struct clk_init_data init = { };
> >>>>>>> +       int ret;
> >>>>>>> +
> >>>>>>> +       ret = of_property_read_string_index(np, "clock-output-names", 1, &init.name);
> >>>>>>> +       if (ret) {
> >>>>>>> +               dev_err(qmp->dev, "%pOFn: No clock-output-names index 1\n", np);
> >>>>>>> +               return ret;
> >>>>>>> +       }
> >>>>>>> +
> >>>>>>> +       init.ops = &clk_fixed_rate_ops;
> >>>>>>> +
> >>>>>>> +       fixed->fixed_rate = qmp->cfg->aux_clock_rate;
> >>>>>>> +       fixed->hw.init = &init;
> >>>>>>> +
> >>>>>>> +       return devm_clk_hw_register(qmp->dev, &fixed->hw);
> >>>>>>> +}
> >>>>>>> +
> >>>>>>> +static struct clk_hw *qmp_pcie_clk_hw_get(struct of_phandle_args *clkspec, void *data)
> >>>>>>> +{
> >>>>>>> +       struct qmp_pcie *qmp = data;
> >>>>>>> +
> >>>>>>> +       /* Support legacy bindings */
> >>>>>>> +       if (!clkspec->args_count)
> >>>>>>> +               return &qmp->pipe_clk_fixed.hw;
> >>>>>>> +
> >>>>>>> +       switch (clkspec->args[0]) {
> >>>>>>> +       case QMP_PCIE_PIPE_CLK:
> >>>>>>> +               return &qmp->pipe_clk_fixed.hw;
> >>>>>>> +       case QMP_PCIE_PHY_AUX_CLK:
> >>>>>>> +               return &qmp->aux_clk_fixed.hw;
> >>>>>>> +       }
> >>>>>>> +
> >>>>>>> +       return ERR_PTR(-EINVAL);
> >>>>>>> +}
> >>>>>>
> >>>>>> Can we use of_clk_hw_onecell_get() instead? I think it even should be
> >>>>>> possible to use onecell for both cases, it will look at the first arg,
> >>>>>> which will be 0 in case of #clock-cells equal to 0.
> >>>>>
> >>>>> Let me investigate if it's possible
> >>>>
> >>>> Ok, it would work but it would require building a clk_hw_onecell_data a runtime,
> >>>> while we could simply provide this qmp_pcie_clk_hw_get() and avoid runtime 2 allocations.
> >>>>
> >>>> I'm not sure it's worth it.
> >>>
> >>> Single allocation (or even 0 allocations if you embed it into struct
> >>> qmp_pcie) for the sake of using standard helpers.
> >>
> >> And I just recall I tried the same for Amlogic clocks, but the clk_hw_onecell_data hws
> >> field is a flexible array member you can't set at runtime, if you try you'll get:
> >> drivers/phy/qualcomm/phy-qcom-qmp-pcie.c:3753:38: error: invalid use of flexible array member
> >>    3753 |                 qmp->clk_hw_data.hws = qmp->clk_hws;
> >
> > Yes, so it's either
> > devm_kzalloc(dev, struct_size(data, hws, 2), GFP_KERNEL);
> > or
> > struct qmp_pcie {
> > ...
> >    struct {
> >      struct clk_hw_onecell_data clk_data;
> >      struct clk_hw clocks[2];
> >    };
> > };
>
> I won't go down this path because of that mess and using of_clk_hw_onecell_get() would need
> to still add a custom getter before calling of_clk_hw_onecell_get() to handle the
> #clock-cells=0 legacy case.

No need for custom getters, if you select the getter during DT probe.
But yes, choose whatever seems better.

>
> Neil
>
> >
> >>
> >> Neil
> >>
> >>>
> >>>
> >>>
> >>
> >
> >
>
diff mbox series

Patch

diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
index 079b3e306489..2d05226ae200 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
+++ b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
@@ -22,6 +22,8 @@ 
 #include <linux/reset.h>
 #include <linux/slab.h>
 
+#include <dt-bindings/phy/phy-qcom-qmp.h>
+
 #include "phy-qcom-qmp-common.h"
 
 #include "phy-qcom-qmp.h"
@@ -2389,6 +2391,9 @@  struct qmp_phy_cfg {
 
 	/* QMP PHY pipe clock interface rate */
 	unsigned long pipe_clock_rate;
+
+	/* QMP PHY AUX clock interface rate */
+	unsigned long aux_clock_rate;
 };
 
 struct qmp_pcie {
@@ -2420,6 +2425,7 @@  struct qmp_pcie {
 	int mode;
 
 	struct clk_fixed_rate pipe_clk_fixed;
+	struct clk_fixed_rate aux_clk_fixed;
 };
 
 static inline void qphy_setbits(void __iomem *base, u32 offset, u32 val)
@@ -3681,6 +3687,62 @@  static int phy_pipe_clk_register(struct qmp_pcie *qmp, struct device_node *np)
 	return devm_clk_hw_register(qmp->dev, &fixed->hw);
 }
 
+/*
+ * Register a fixed rate PHY aux clock.
+ *
+ * The <s>_phy_aux_clksrc generated by PHY goes to the GCC that gate
+ * controls it. The <s>_phy_aux_clk coming out of the GCC is requested
+ * by the PHY driver for its operations.
+ * We register the <s>_phy_aux_clksrc here. The gcc driver takes care
+ * of assigning this <s>_phy_aux_clksrc as parent to <s>_phy_aux_clk.
+ * Below picture shows this relationship.
+ *
+ *         +---------------+
+ *         |   PHY block   |<<---------------------------------------------+
+ *         |               |                                               |
+ *         |   +-------+   |                      +-----+                  |
+ *   I/P---^-->|  PLL  |---^--->phy_aux_clksrc--->| GCC |--->phy_aux_clk---+
+ *    clk  |   +-------+   |                      +-----+
+ *         +---------------+
+ */
+static int phy_aux_clk_register(struct qmp_pcie *qmp, struct device_node *np)
+{
+	struct clk_fixed_rate *fixed = &qmp->aux_clk_fixed;
+	struct clk_init_data init = { };
+	int ret;
+
+	ret = of_property_read_string_index(np, "clock-output-names", 1, &init.name);
+	if (ret) {
+		dev_err(qmp->dev, "%pOFn: No clock-output-names index 1\n", np);
+		return ret;
+	}
+
+	init.ops = &clk_fixed_rate_ops;
+
+	fixed->fixed_rate = qmp->cfg->aux_clock_rate;
+	fixed->hw.init = &init;
+
+	return devm_clk_hw_register(qmp->dev, &fixed->hw);
+}
+
+static struct clk_hw *qmp_pcie_clk_hw_get(struct of_phandle_args *clkspec, void *data)
+{
+	struct qmp_pcie *qmp = data;
+
+	/* Support legacy bindings */
+	if (!clkspec->args_count)
+		return &qmp->pipe_clk_fixed.hw;
+
+	switch (clkspec->args[0]) {
+	case QMP_PCIE_PIPE_CLK:
+		return &qmp->pipe_clk_fixed.hw;
+	case QMP_PCIE_PHY_AUX_CLK:
+		return &qmp->aux_clk_fixed.hw;
+	}
+
+	return ERR_PTR(-EINVAL);
+}
+
 static int qmp_pcie_register_clocks(struct qmp_pcie *qmp, struct device_node *np)
 {
 	int ret;
@@ -3689,6 +3751,14 @@  static int qmp_pcie_register_clocks(struct qmp_pcie *qmp, struct device_node *np
 	if (ret)
 		return ret;
 
+	if (qmp->cfg->aux_clock_rate) {
+		ret = phy_aux_clk_register(qmp, np);
+		if (ret)
+			return ret;
+
+		return devm_of_clk_add_hw_provider(qmp->dev, qmp_pcie_clk_hw_get, qmp);
+	}
+
 	return devm_of_clk_add_hw_provider(qmp->dev, of_clk_hw_simple_get,
 					   &qmp->pipe_clk_fixed.hw);
 }