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Message-ID: <18a3bc0c5b371deec5c4bbe6ceacf8afcf0bc640.1693996662.git.quic_varada@quicinc.com>
Date: Thu, 7 Sep 2023 10:51:36 +0530
From: Varadarajan Narayanan <quic_varada@...cinc.com>
To: <ilia.lin@...nel.org>, <agross@...nel.org>, <andersson@...nel.org>,
<konrad.dybcio@...aro.org>, <rafael@...nel.org>,
<viresh.kumar@...aro.org>, <robh+dt@...nel.org>,
<krzysztof.kozlowski+dt@...aro.org>, <conor+dt@...nel.org>,
<mturquette@...libre.com>, <sboyd@...nel.org>,
<quic_kathirav@...cinc.com>, <linux-pm@...r.kernel.org>,
<linux-arm-msm@...r.kernel.org>, <devicetree@...r.kernel.org>,
<linux-kernel@...r.kernel.org>, <linux-clk@...r.kernel.org>
CC: Varadarajan Narayanan <quic_varada@...cinc.com>
Subject: [PATCH v1 01/10] clk: qcom: clk-alpha-pll: introduce stromer plus ops
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@...cinc.com>
Signed-off-by: Varadarajan Narayanan <quic_varada@...cinc.com>
---
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;
+}
+
+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
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