linux-kernel - [PATCH 1/2] clk: qcom: clk-krait: switch to .determine

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Message-Id: <20230212-clk-qcom-determine_rate-v1-1-b4e447d4926e@z3ntu.xyz>
Date:   Sun, 12 Feb 2023 15:11:08 +0100
From:   Luca Weiss <luca@...tu.xyz>
To:     ~postmarketos/upstreaming@...ts.sr.ht, phone-devel@...r.kernel.org,
        Bjorn Andersson <andersson@...nel.org>,
        Andy Gross <agross@...nel.org>,
        Konrad Dybcio <konrad.dybcio@...aro.org>,
        Michael Turquette <mturquette@...libre.com>,
        Stephen Boyd <sboyd@...nel.org>,
        Christian Marangi <ansuelsmth@...il.com>
Cc:     linux-arm-msm@...r.kernel.org, linux-clk@...r.kernel.org,
        linux-kernel@...r.kernel.org, Luca Weiss <luca@...tu.xyz>
Subject: [PATCH 1/2] clk: qcom: clk-krait: switch to .determine_rate

.determine_rate is meant to replace .round_rate. The former comes with a
benefit which is especially relevant on 32-bit systems: since
.determine_rate uses an "unsigned long" (compared to a "signed long"
which is used by .round_rate) the maximum value on 32-bit systems
increases from 2^31 (or approx. 2.14GHz) to 2^32 (or approx. 4.29GHz).

Signed-off-by: Luca Weiss <luca@...tu.xyz>
---
 drivers/clk/qcom/clk-krait.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/clk/qcom/clk-krait.c b/drivers/clk/qcom/clk-krait.c
index 293a9dfa7151..f5ce403e1e27 100644
--- a/drivers/clk/qcom/clk-krait.c
+++ b/drivers/clk/qcom/clk-krait.c
@@ -97,11 +97,11 @@ const struct clk_ops krait_mux_clk_ops = {
 EXPORT_SYMBOL_GPL(krait_mux_clk_ops);
 
 /* The divider can divide by 2, 4, 6 and 8. But we only really need div-2. */
-static long krait_div2_round_rate(struct clk_hw *hw, unsigned long rate,
-				  unsigned long *parent_rate)
+static int krait_div2_determine_rate(struct clk_hw *hw, struct clk_rate_request *req)
 {
-	*parent_rate = clk_hw_round_rate(clk_hw_get_parent(hw), rate * 2);
-	return DIV_ROUND_UP(*parent_rate, 2);
+	req->best_parent_rate = clk_hw_round_rate(clk_hw_get_parent(hw), req->rate * 2);
+	req->rate = DIV_ROUND_UP(req->best_parent_rate, 2);
+	return 0;
 }
 
 static int krait_div2_set_rate(struct clk_hw *hw, unsigned long rate,
@@ -142,7 +142,7 @@ krait_div2_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
 }
 
 const struct clk_ops krait_div2_clk_ops = {
-	.round_rate = krait_div2_round_rate,
+	.determine_rate = krait_div2_determine_rate,
 	.set_rate = krait_div2_set_rate,
 	.recalc_rate = krait_div2_recalc_rate,
 };

-- 
2.39.1