[v1,01/10] clk: qcom: clk-alpha-pll: introduce stromer plus ops

Commit Message

Varadarajan Narayanan Sept. 7, 2023, 5:21 a.m. UTC

Stromer plus APSS PLL does not support dynamic frequency scaling.
To switch between frequencies, we have to shut down the PLL,
configure the L and ALPHA values and turn on again. So introduce the
separate set of ops for Stromer Plus PLL.

Signed-off-by: Kathiravan T <[e-mail]>
Signed-off-by: Varadarajan Narayanan <[e-mail]>
---
 drivers/clk/qcom/clk-alpha-pll.c | 68 ++++++++++++++++++++++++++++++++++++++++
 drivers/clk/qcom/clk-alpha-pll.h |  1 +
 2 files changed, 69 insertions(+)

Comments

Konrad Dybcio Sept. 7, 2023, 8:24 a.m. UTC | #1

On 7.09.2023 07:21, Varadarajan Narayanan wrote:
> Stromer plus APSS PLL does not support dynamic frequency scaling.
> To switch between frequencies, we have to shut down the PLL,
> configure the L and ALPHA values and turn on again. So introduce the
> separate set of ops for Stromer Plus PLL.
> 
> Signed-off-by: Kathiravan T <[e-mail]>
> Signed-off-by: Varadarajan Narayanan <[e-mail]>
> ---
[...]

> +
> +	/* Wait five micro seconds or more */
> +	udelay(5);
> +	regmap_update_bits(pll->clkr.regmap, PLL_MODE(pll), PLL_RESET_N,
> +			   PLL_RESET_N);
> +
> +	/* The lock time should be less than 50 micro seconds worst case */
> +	udelay(50);
https://www.kernel.org/doc/Documentation/timers/timers-howto.txt

> +
> +	ret = wait_for_pll_enable_lock(pll);
> +	if (ret) {
> +		pr_err("alpha pll running in 800 MHz with source GPLL0\n");
> +		return ret;
> +	}
Would that not be SoC-specific information?

Konrad

Dmitry Baryshkov Sept. 7, 2023, 1:39 p.m. UTC | #2

On Thu, 7 Sept 2023 at 08:22, Varadarajan Narayanan
<[e-mail]> wrote:
>
> Stromer plus APSS PLL does not support dynamic frequency scaling.
> To switch between frequencies, we have to shut down the PLL,
> configure the L and ALPHA values and turn on again. So introduce the
> separate set of ops for Stromer Plus PLL.
>
> Signed-off-by: Kathiravan T <[e-mail]>
> Signed-off-by: Varadarajan Narayanan <[e-mail]>
> ---
>  drivers/clk/qcom/clk-alpha-pll.c | 68 ++++++++++++++++++++++++++++++++++++++++
>  drivers/clk/qcom/clk-alpha-pll.h |  1 +
>  2 files changed, 69 insertions(+)
>
> diff --git a/drivers/clk/qcom/clk-alpha-pll.c b/drivers/clk/qcom/clk-alpha-pll.c
> index e4ef645..2ef81f7 100644
> --- a/drivers/clk/qcom/clk-alpha-pll.c
> +++ b/drivers/clk/qcom/clk-alpha-pll.c
> @@ -2479,3 +2479,71 @@ const struct clk_ops clk_alpha_pll_stromer_ops = {
>         .set_rate = clk_alpha_pll_stromer_set_rate,
>  };
>  EXPORT_SYMBOL_GPL(clk_alpha_pll_stromer_ops);
> +
> +static int clk_alpha_pll_stromer_plus_determine_rate(struct clk_hw *hw,
> +                                                    struct clk_rate_request *req)
> +{
> +       struct clk_alpha_pll *pll = to_clk_alpha_pll(hw);
> +       u32 l, alpha_width = pll_alpha_width(pll);
> +       u64 a;
> +
> +       req->rate = alpha_pll_round_rate(req->rate, req->best_parent_rate, &l,
> +                                        &a, alpha_width);
> +       return 0;
> +}

What is the plL_alpha_width on stromer_plus? Does
clk_alpha_pll_stromer_determine_rate() work for you?

> +
> +static int clk_alpha_pll_stromer_plus_set_rate(struct clk_hw *hw,
> +                                              unsigned long rate,
> +                                              unsigned long prate)
> +{
> +       struct clk_alpha_pll *pll = to_clk_alpha_pll(hw);
> +       u32 l, alpha_width = pll_alpha_width(pll);
> +       int ret;
> +       u64 a;
> +
> +       rate = alpha_pll_round_rate(rate, prate, &l, &a, alpha_width);
> +
> +       regmap_write(pll->clkr.regmap, PLL_MODE(pll), 0);
> +
> +       /* Delay of 2 output clock ticks required until output is disabled */
> +       udelay(1);
> +
> +       regmap_write(pll->clkr.regmap, PLL_L_VAL(pll), l);
> +
> +       if (alpha_width > ALPHA_BITWIDTH)
> +               a <<= alpha_width - ALPHA_BITWIDTH;
> +
> +       regmap_write(pll->clkr.regmap, PLL_ALPHA_VAL(pll), a);
> +       regmap_write(pll->clkr.regmap, PLL_ALPHA_VAL_U(pll),
> +                                       a >> ALPHA_BITWIDTH);
> +
> +       regmap_write(pll->clkr.regmap, PLL_MODE(pll), PLL_BYPASSNL);
> +
> +       /* Wait five micro seconds or more */
> +       udelay(5);
> +       regmap_update_bits(pll->clkr.regmap, PLL_MODE(pll), PLL_RESET_N,
> +                          PLL_RESET_N);
> +
> +       /* The lock time should be less than 50 micro seconds worst case */
> +       udelay(50);
> +
> +       ret = wait_for_pll_enable_lock(pll);
> +       if (ret) {
> +               pr_err("alpha pll running in 800 MHz with source GPLL0\n");
> +               return ret;
> +       }
> +       regmap_update_bits(pll->clkr.regmap, PLL_MODE(pll), PLL_OUTCTRL,
> +                          PLL_OUTCTRL);
> +
> +       return 0;
> +}
> +
> +const struct clk_ops clk_alpha_pll_stromer_plus_ops = {
> +       .enable = clk_alpha_pll_enable,
> +       .disable = clk_alpha_pll_disable,
> +       .is_enabled = clk_alpha_pll_is_enabled,
> +       .recalc_rate = clk_alpha_pll_recalc_rate,
> +       .determine_rate = clk_alpha_pll_stromer_plus_determine_rate,
> +       .set_rate = clk_alpha_pll_stromer_plus_set_rate,
> +};
> +EXPORT_SYMBOL_GPL(clk_alpha_pll_stromer_plus_ops);
> diff --git a/drivers/clk/qcom/clk-alpha-pll.h b/drivers/clk/qcom/clk-alpha-pll.h
> index e4bd863..903fbab 100644
> --- a/drivers/clk/qcom/clk-alpha-pll.h
> +++ b/drivers/clk/qcom/clk-alpha-pll.h
> @@ -152,6 +152,7 @@ extern const struct clk_ops clk_alpha_pll_postdiv_ops;
>  extern const struct clk_ops clk_alpha_pll_huayra_ops;
>  extern const struct clk_ops clk_alpha_pll_postdiv_ro_ops;
>  extern const struct clk_ops clk_alpha_pll_stromer_ops;
> +extern const struct clk_ops clk_alpha_pll_stromer_plus_ops;
>
>  extern const struct clk_ops clk_alpha_pll_fabia_ops;
>  extern const struct clk_ops clk_alpha_pll_fixed_fabia_ops;
> --
> 2.7.4
>

Varadarajan Narayanan Sept. 29, 2023, 7:21 a.m. UTC | #3

On Thu, Sep 07, 2023 at 04:39:33PM +0300, Dmitry Baryshkov wrote:
> On Thu, 7 Sept 2023 at 08:22, Varadarajan Narayanan
> <[e-mail]> wrote:
> >
> > Stromer plus APSS PLL does not support dynamic frequency scaling.
> > To switch between frequencies, we have to shut down the PLL,
> > configure the L and ALPHA values and turn on again. So introduce the
> > separate set of ops for Stromer Plus PLL.
> >
> > Signed-off-by: Kathiravan T <[e-mail]>
> > Signed-off-by: Varadarajan Narayanan <[e-mail]>
> > ---
> >  drivers/clk/qcom/clk-alpha-pll.c | 68 ++++++++++++++++++++++++++++++++++++++++
> >  drivers/clk/qcom/clk-alpha-pll.h |  1 +
> >  2 files changed, 69 insertions(+)
> >
> > diff --git a/drivers/clk/qcom/clk-alpha-pll.c b/drivers/clk/qcom/clk-alpha-pll.c
> > index e4ef645..2ef81f7 100644
> > --- a/drivers/clk/qcom/clk-alpha-pll.c
> > +++ b/drivers/clk/qcom/clk-alpha-pll.c
> > @@ -2479,3 +2479,71 @@ const struct clk_ops clk_alpha_pll_stromer_ops = {
> >         .set_rate = clk_alpha_pll_stromer_set_rate,
> >  };
> >  EXPORT_SYMBOL_GPL(clk_alpha_pll_stromer_ops);
> > +
> > +static int clk_alpha_pll_stromer_plus_determine_rate(struct clk_hw *hw,
> > +                                                    struct clk_rate_request *req)
> > +{
> > +       struct clk_alpha_pll *pll = to_clk_alpha_pll(hw);
> > +       u32 l, alpha_width = pll_alpha_width(pll);
> > +       u64 a;
> > +
> > +       req->rate = alpha_pll_round_rate(req->rate, req->best_parent_rate, &l,
> > +                                        &a, alpha_width);
> > +       return 0;
> > +}
>
> What is the plL_alpha_width on stromer_plus? Does
> clk_alpha_pll_stromer_determine_rate() work for you?

pll_alpha_width is 4. I tested with clk_alpha_pll_stromer_determine_rate()
and it works. Will change and post a new version.

Thanks
Varada

> > +
> > +static int clk_alpha_pll_stromer_plus_set_rate(struct clk_hw *hw,
> > +                                              unsigned long rate,
> > +                                              unsigned long prate)
> > +{
> > +       struct clk_alpha_pll *pll = to_clk_alpha_pll(hw);
> > +       u32 l, alpha_width = pll_alpha_width(pll);
> > +       int ret;
> > +       u64 a;
> > +
> > +       rate = alpha_pll_round_rate(rate, prate, &l, &a, alpha_width);
> > +
> > +       regmap_write(pll->clkr.regmap, PLL_MODE(pll), 0);
> > +
> > +       /* Delay of 2 output clock ticks required until output is disabled */
> > +       udelay(1);
> > +
> > +       regmap_write(pll->clkr.regmap, PLL_L_VAL(pll), l);
> > +
> > +       if (alpha_width > ALPHA_BITWIDTH)
> > +               a <<= alpha_width - ALPHA_BITWIDTH;
> > +
> > +       regmap_write(pll->clkr.regmap, PLL_ALPHA_VAL(pll), a);
> > +       regmap_write(pll->clkr.regmap, PLL_ALPHA_VAL_U(pll),
> > +                                       a >> ALPHA_BITWIDTH);
> > +
> > +       regmap_write(pll->clkr.regmap, PLL_MODE(pll), PLL_BYPASSNL);
> > +
> > +       /* Wait five micro seconds or more */
> > +       udelay(5);
> > +       regmap_update_bits(pll->clkr.regmap, PLL_MODE(pll), PLL_RESET_N,
> > +                          PLL_RESET_N);
> > +
> > +       /* The lock time should be less than 50 micro seconds worst case */
> > +       udelay(50);
> > +
> > +       ret = wait_for_pll_enable_lock(pll);
> > +       if (ret) {
> > +               pr_err("alpha pll running in 800 MHz with source GPLL0\n");
> > +               return ret;
> > +       }
> > +       regmap_update_bits(pll->clkr.regmap, PLL_MODE(pll), PLL_OUTCTRL,
> > +                          PLL_OUTCTRL);
> > +
> > +       return 0;
> > +}
> > +
> > +const struct clk_ops clk_alpha_pll_stromer_plus_ops = {
> > +       .enable = clk_alpha_pll_enable,
> > +       .disable = clk_alpha_pll_disable,
> > +       .is_enabled = clk_alpha_pll_is_enabled,
> > +       .recalc_rate = clk_alpha_pll_recalc_rate,
> > +       .determine_rate = clk_alpha_pll_stromer_plus_determine_rate,
> > +       .set_rate = clk_alpha_pll_stromer_plus_set_rate,
> > +};
> > +EXPORT_SYMBOL_GPL(clk_alpha_pll_stromer_plus_ops);
> > diff --git a/drivers/clk/qcom/clk-alpha-pll.h b/drivers/clk/qcom/clk-alpha-pll.h
> > index e4bd863..903fbab 100644
> > --- a/drivers/clk/qcom/clk-alpha-pll.h
> > +++ b/drivers/clk/qcom/clk-alpha-pll.h
> > @@ -152,6 +152,7 @@ extern const struct clk_ops clk_alpha_pll_postdiv_ops;
> >  extern const struct clk_ops clk_alpha_pll_huayra_ops;
> >  extern const struct clk_ops clk_alpha_pll_postdiv_ro_ops;
> >  extern const struct clk_ops clk_alpha_pll_stromer_ops;
> > +extern const struct clk_ops clk_alpha_pll_stromer_plus_ops;
> >
> >  extern const struct clk_ops clk_alpha_pll_fabia_ops;
> >  extern const struct clk_ops clk_alpha_pll_fixed_fabia_ops;
> > --
> > 2.7.4
> >
>
>
> --
> With best wishes
> Dmitry

Patch

diff --git a/drivers/clk/qcom/clk-alpha-pll.c b/drivers/clk/qcom/clk-alpha-pll.c
index e4ef645..2ef81f7 100644
--- a/drivers/clk/qcom/clk-alpha-pll.c
+++ b/drivers/clk/qcom/clk-alpha-pll.c
@@ -2479,3 +2479,71 @@  const struct clk_ops clk_alpha_pll_stromer_ops = {
 	.set_rate = clk_alpha_pll_stromer_set_rate,
 };
 EXPORT_SYMBOL_GPL(clk_alpha_pll_stromer_ops);
+
+static int clk_alpha_pll_stromer_plus_determine_rate(struct clk_hw *hw,
+						     struct clk_rate_request *req)
+{
+	struct clk_alpha_pll *pll = to_clk_alpha_pll(hw);
+	u32 l, alpha_width = pll_alpha_width(pll);
+	u64 a;
+
+	req->rate = alpha_pll_round_rate(req->rate, req->best_parent_rate, &l,
+					 &a, alpha_width);
+	return 0;
+}
+
+static int clk_alpha_pll_stromer_plus_set_rate(struct clk_hw *hw,
+					       unsigned long rate,
+					       unsigned long prate)
+{
+	struct clk_alpha_pll *pll = to_clk_alpha_pll(hw);
+	u32 l, alpha_width = pll_alpha_width(pll);
+	int ret;
+	u64 a;
+
+	rate = alpha_pll_round_rate(rate, prate, &l, &a, alpha_width);
+
+	regmap_write(pll->clkr.regmap, PLL_MODE(pll), 0);
+
+	/* Delay of 2 output clock ticks required until output is disabled */
+	udelay(1);
+
+	regmap_write(pll->clkr.regmap, PLL_L_VAL(pll), l);
+
+	if (alpha_width > ALPHA_BITWIDTH)
+		a <<= alpha_width - ALPHA_BITWIDTH;
+
+	regmap_write(pll->clkr.regmap, PLL_ALPHA_VAL(pll), a);
+	regmap_write(pll->clkr.regmap, PLL_ALPHA_VAL_U(pll),
+					a >> ALPHA_BITWIDTH);
+
+	regmap_write(pll->clkr.regmap, PLL_MODE(pll), PLL_BYPASSNL);
+
+	/* Wait five micro seconds or more */
+	udelay(5);
+	regmap_update_bits(pll->clkr.regmap, PLL_MODE(pll), PLL_RESET_N,
+			   PLL_RESET_N);
+
+	/* The lock time should be less than 50 micro seconds worst case */
+	udelay(50);
+
+	ret = wait_for_pll_enable_lock(pll);
+	if (ret) {
+		pr_err("alpha pll running in 800 MHz with source GPLL0\n");
+		return ret;
+	}
+	regmap_update_bits(pll->clkr.regmap, PLL_MODE(pll), PLL_OUTCTRL,
+			   PLL_OUTCTRL);
+
+	return 0;
+}
+
+const struct clk_ops clk_alpha_pll_stromer_plus_ops = {
+	.enable = clk_alpha_pll_enable,
+	.disable = clk_alpha_pll_disable,
+	.is_enabled = clk_alpha_pll_is_enabled,
+	.recalc_rate = clk_alpha_pll_recalc_rate,
+	.determine_rate = clk_alpha_pll_stromer_plus_determine_rate,
+	.set_rate = clk_alpha_pll_stromer_plus_set_rate,
+};
+EXPORT_SYMBOL_GPL(clk_alpha_pll_stromer_plus_ops);
diff --git a/drivers/clk/qcom/clk-alpha-pll.h b/drivers/clk/qcom/clk-alpha-pll.h
index e4bd863..903fbab 100644
--- a/drivers/clk/qcom/clk-alpha-pll.h
+++ b/drivers/clk/qcom/clk-alpha-pll.h
@@ -152,6 +152,7 @@  extern const struct clk_ops clk_alpha_pll_postdiv_ops;
 extern const struct clk_ops clk_alpha_pll_huayra_ops;
 extern const struct clk_ops clk_alpha_pll_postdiv_ro_ops;
 extern const struct clk_ops clk_alpha_pll_stromer_ops;
+extern const struct clk_ops clk_alpha_pll_stromer_plus_ops;
 
 extern const struct clk_ops clk_alpha_pll_fabia_ops;
 extern const struct clk_ops clk_alpha_pll_fixed_fabia_ops;