204 lines
5.4 KiB
Diff
204 lines
5.4 KiB
Diff
From 032be4f49dda786fea9e1501212f6cd09a7ded96 Mon Sep 17 00:00:00 2001
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From: Christian Marangi <ansuelsmth@gmail.com>
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Date: Thu, 3 Nov 2022 14:49:43 +0100
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Subject: [PATCH] clk: qcom: clk-rcg2: introduce support for multiple conf for
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same freq
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Some RCG frequency can be reached by multiple configuration.
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We currently declare multiple configuration for the same frequency but
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that is not supported and always the first configuration will be taken.
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These multiple configuration are needed as based on the current parent
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configuration, it may be needed to use a different configuration to
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reach the same frequency.
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To handle this introduce 2 new macro, FM and C.
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- FM is used to declare an empty freq_tbl with just the frequency and an
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array of confs to insert all the config for the provided frequency.
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- C is used to declare a fre_conf where src, pre_div, m and n are
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provided.
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The driver is changed to handle this special freq_tbl and select the
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correct config by calculating the final rate and deciding based on the
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one that is less different than the requested one.
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Tested-by: Robert Marko <robimarko@gmail.com>
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Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
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---
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drivers/clk/qcom/clk-rcg.h | 14 ++++++-
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drivers/clk/qcom/clk-rcg2.c | 84 +++++++++++++++++++++++++++++++++----
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2 files changed, 88 insertions(+), 10 deletions(-)
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--- a/drivers/clk/qcom/clk-rcg.h
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+++ b/drivers/clk/qcom/clk-rcg.h
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@@ -7,7 +7,17 @@
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#include <linux/clk-provider.h>
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#include "clk-regmap.h"
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-#define F(f, s, h, m, n) { (f), (s), (2 * (h) - 1), (m), (n) }
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+#define F(f, s, h, m, n) { (f), (s), (2 * (h) - 1), (m), (n), 0, NULL }
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+
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+#define FM(_f, _confs) { .freq = (_f), .confs_num = ARRAY_SIZE(_confs), .confs = (_confs) }
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+#define C(s, h, m, n) { (s), (2 * (h) - 1), (m), (n) }
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+
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+struct freq_conf {
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+ u8 src;
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+ u8 pre_div;
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+ u16 m;
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+ u16 n;
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+};
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struct freq_tbl {
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unsigned long freq;
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@@ -15,6 +25,8 @@ struct freq_tbl {
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u8 pre_div;
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u16 m;
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u16 n;
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+ int confs_num;
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+ const struct freq_conf *confs;
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};
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/**
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--- a/drivers/clk/qcom/clk-rcg2.c
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+++ b/drivers/clk/qcom/clk-rcg2.c
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@@ -203,11 +203,60 @@ clk_rcg2_recalc_rate(struct clk_hw *hw,
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return __clk_rcg2_recalc_rate(hw, parent_rate, cfg);
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}
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+static void
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+clk_rcg2_select_conf(struct clk_hw *hw, struct freq_tbl *f_tbl,
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+ const struct freq_tbl *f, unsigned long req_rate)
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+{
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+ unsigned long best_rate = 0, parent_rate, rate;
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+ const struct freq_conf *conf, *best_conf;
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+ struct clk_rcg2 *rcg = to_clk_rcg2(hw);
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+ struct clk_hw *p;
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+ int index, i;
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+
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+ /* Search in each provided config the one that is near the wanted rate */
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+ for (i = 0, conf = f->confs; i < f->confs_num; i++, conf++) {
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+ index = qcom_find_src_index(hw, rcg->parent_map, conf->src);
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+ if (index < 0)
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+ continue;
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+
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+ p = clk_hw_get_parent_by_index(hw, index);
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+ if (!p)
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+ continue;
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+
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+ parent_rate = clk_hw_get_rate(p);
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+ rate = calc_rate(parent_rate, conf->n, conf->m, conf->n, conf->pre_div);
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+
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+ if (rate == req_rate) {
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+ best_conf = conf;
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+ break;
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+ }
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+
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+ if (abs(req_rate - rate) < abs(best_rate - rate)) {
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+ best_rate = rate;
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+ best_conf = conf;
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+ }
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+ }
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+
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+ /*
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+ * Very unlikely.
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+ * Force the first conf if we can't find a correct config.
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+ */
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+ if (unlikely(i == f->confs_num))
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+ best_conf = f->confs;
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+
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+ /* Apply the config */
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+ f_tbl->src = best_conf->src;
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+ f_tbl->pre_div = best_conf->pre_div;
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+ f_tbl->m = best_conf->m;
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+ f_tbl->n = best_conf->n;
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+}
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+
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static int _freq_tbl_determine_rate(struct clk_hw *hw, const struct freq_tbl *f,
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struct clk_rate_request *req,
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enum freq_policy policy)
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{
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unsigned long clk_flags, rate = req->rate;
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+ struct freq_tbl f_tbl;
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struct clk_hw *p;
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struct clk_rcg2 *rcg = to_clk_rcg2(hw);
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int index;
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@@ -226,7 +275,15 @@ static int _freq_tbl_determine_rate(stru
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if (!f)
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return -EINVAL;
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- index = qcom_find_src_index(hw, rcg->parent_map, f->src);
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+ f_tbl = *f;
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+ /*
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+ * A single freq may be reached by multiple configuration.
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+ * Try to find the bast one if we have this kind of freq_table.
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+ */
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+ if (f->confs)
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+ clk_rcg2_select_conf(hw, &f_tbl, f, rate);
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+
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+ index = qcom_find_src_index(hw, rcg->parent_map, f_tbl.src);
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if (index < 0)
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return index;
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@@ -236,18 +293,18 @@ static int _freq_tbl_determine_rate(stru
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return -EINVAL;
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if (clk_flags & CLK_SET_RATE_PARENT) {
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- rate = f->freq;
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- if (f->pre_div) {
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+ rate = f_tbl.freq;
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+ if (f_tbl.pre_div) {
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if (!rate)
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rate = req->rate;
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rate /= 2;
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- rate *= f->pre_div + 1;
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+ rate *= f_tbl.pre_div + 1;
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}
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- if (f->n) {
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+ if (f_tbl.n) {
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u64 tmp = rate;
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- tmp = tmp * f->n;
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- do_div(tmp, f->m);
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+ tmp = tmp * f_tbl.n;
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+ do_div(tmp, f_tbl.m);
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rate = tmp;
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}
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} else {
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@@ -255,7 +312,7 @@ static int _freq_tbl_determine_rate(stru
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}
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req->best_parent_hw = p;
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req->best_parent_rate = rate;
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- req->rate = f->freq;
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+ req->rate = f_tbl.freq;
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return 0;
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}
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@@ -351,6 +408,7 @@ static int __clk_rcg2_set_rate(struct cl
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{
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struct clk_rcg2 *rcg = to_clk_rcg2(hw);
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const struct freq_tbl *f;
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+ struct freq_tbl f_tbl;
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switch (policy) {
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case FLOOR:
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@@ -366,7 +424,15 @@ static int __clk_rcg2_set_rate(struct cl
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if (!f)
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return -EINVAL;
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- return clk_rcg2_configure(rcg, f);
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+ f_tbl = *f;
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+ /*
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+ * A single freq may be reached by multiple configuration.
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+ * Try to find the best one if we have this kind of freq_table.
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+ */
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+ if (f->confs)
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+ clk_rcg2_select_conf(hw, &f_tbl, f, rate);
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+
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+ return clk_rcg2_configure(rcg, &f_tbl);
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}
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static int clk_rcg2_set_rate(struct clk_hw *hw, unsigned long rate,
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