svn commit: r365942 - in stable/12/sys: arm/allwinner/clkng dev/extres/clk

[Andriy Gapon]

Author: avg
Date: Mon Sep 21 09:50:57 2020
New Revision: 365942
URL: https://svnweb.freebsd.org/changeset/base/365942

Log:
  MFC r363887 (by manu), r365395: allwinner: clk: Fix nm clock calculation
  
  r363887:
  Use the right factor when finding the best frequency and compare the
  absolute value of the result.
  Submitted by:	kibab
  
  r365395:
  aw_clk_nm: fix incorrect use of abs()
  abs() takes a (signed) int as input.
  Instead, it was used with unsigned 64-bit integers.
  So, add and use a new helper function to calculate a difference between
  two uint64_t-s.

Modified:
  stable/12/sys/arm/allwinner/clkng/aw_clk_nm.c
  stable/12/sys/dev/extres/clk/clk.h
Directory Properties:
  stable/12/   (props changed)

Modified: stable/12/sys/arm/allwinner/clkng/aw_clk_nm.c
==============================================================================
--- stable/12/sys/arm/allwinner/clkng/aw_clk_nm.c	Mon Sep 21 09:03:42 2020	(r365941)
+++ stable/12/sys/arm/allwinner/clkng/aw_clk_nm.c	Mon Sep 21 09:50:57 2020	(r365942)
@@ -152,9 +152,10 @@ aw_clk_nm_find_best(struct aw_clk_nm_sc *sc, uint64_t 
 	min_n = aw_clk_factor_get_min(&sc->n);
 
 	for (m = min_m; m <= max_m; ) {
-		for (n = min_m; n <= max_n; ) {
+		for (n = min_n; n <= max_n; ) {
 			cur = fparent / n / m;
-			if (abs(*fout - cur) < abs(*fout - best)) {
+			if (clk_freq_diff(*fout, cur) <
+			    clk_freq_diff(*fout, best)) {
 				best = cur;
 				*factor_n = n;
 				*factor_m = m;
@@ -197,7 +198,8 @@ aw_clk_nm_set_freq(struct clknode *clk, uint64_t fpare
 			clknode_get_freq(p_clk, &fparent);
 
 			cur = aw_clk_nm_find_best(sc, fparent, fout, &n, &m);
-			if ((*fout - cur) < (*fout - best)) {
+			if (clk_freq_diff(*fout, cur) <
+			    clk_freq_diff(*fout, best)) {
 				best = cur;
 				best_parent = p_idx;
 				best_n = n;

Modified: stable/12/sys/dev/extres/clk/clk.h
==============================================================================
--- stable/12/sys/dev/extres/clk/clk.h	Mon Sep 21 09:03:42 2020	(r365941)
+++ stable/12/sys/dev/extres/clk/clk.h	Mon Sep 21 09:50:57 2020	(r365942)
@@ -135,6 +135,12 @@ int clk_get_parent(clk_t clk, clk_t *parent);
 int clk_set_parent_by_clk(clk_t clk, clk_t parent);
 const char *clk_get_name(clk_t clk);
 
+static inline uint64_t
+clk_freq_diff(uint64_t x, uint64_t y)
+{
+	return (x >= y ? x - y : y - x);
+}
+
 #ifdef FDT
 int clk_set_assigned(device_t dev, phandle_t node);
 int clk_get_by_ofw_index(device_t dev, phandle_t node, int idx, clk_t *clk);