diff mbox series

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

Message ID 18a3bc0c5b371deec5c4bbe6ceacf8afcf0bc640.1693996662.git.quic_varada@quicinc.com
State Superseded
Headers show
Series Enable cpufreq for IPQ5332 & IPQ9574 | expand

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 <quic_kathirav@quicinc.com>
Signed-off-by: Varadarajan Narayanan <quic_varada@quicinc.com>
---
 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 <quic_kathirav@quicinc.com>
> Signed-off-by: Varadarajan Narayanan <quic_varada@quicinc.com>
> ---
[...]

> +
> +	/* 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
diff mbox series

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;