aboutsummaryrefslogtreecommitdiffstats
path: root/target/linux/brcm2708/patches-4.9/950-0155-clk-bcm2835-Don-t-rate-change-PLLs-on-behalf-of-DSI-.patch
blob: 154e06115579608e4b1b8f7bae5174fd2967c0a5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
From 999db52750c062708532e1357ea3942cc619794f Mon Sep 17 00:00:00 2001
From: Eric Anholt <eric@anholt.net>
Date: Wed, 18 Jan 2017 07:31:55 +1100
Subject: [PATCH] clk: bcm2835: Don't rate change PLLs on behalf of DSI PLL
 dividers.

Our core PLLs are intended to be configured once and left alone.  With
the SET_RATE_PARENT, asking to set the PLLD_DSI1 clock rate would
change PLLD just to get closer to the requested DSI clock, thus
changing PLLD_PER, the UART and ethernet PHY clock rates downstream of
it, and breaking ethernet.

We *do* want PLLH to change so that PLLH_AUX can be exactly the value
we want, though.  Thus, we need to have a per-divider policy of
whether to pass rate changes up.

Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
(cherry picked from commit 55486091bd1e1c5ed28c43c0d6b3392468a9adb5)
---
 drivers/clk/bcm/clk-bcm2835.c | 42 ++++++++++++++++++++++++++++--------------
 1 file changed, 28 insertions(+), 14 deletions(-)

--- a/drivers/clk/bcm/clk-bcm2835.c
+++ b/drivers/clk/bcm/clk-bcm2835.c
@@ -428,6 +428,7 @@ struct bcm2835_pll_divider_data {
 	u32 load_mask;
 	u32 hold_mask;
 	u32 fixed_divider;
+	u32 flags;
 };
 
 struct bcm2835_clock_data {
@@ -1252,7 +1253,7 @@ bcm2835_register_pll_divider(struct bcm2
 	init.num_parents = 1;
 	init.name = divider_name;
 	init.ops = &bcm2835_pll_divider_clk_ops;
-	init.flags = CLK_SET_RATE_PARENT | CLK_IGNORE_UNUSED;
+	init.flags = data->flags | CLK_IGNORE_UNUSED;
 
 	divider = devm_kzalloc(cprman->dev, sizeof(*divider), GFP_KERNEL);
 	if (!divider)
@@ -1475,7 +1476,8 @@ static const struct bcm2835_clk_desc clk
 		.a2w_reg = A2W_PLLA_CORE,
 		.load_mask = CM_PLLA_LOADCORE,
 		.hold_mask = CM_PLLA_HOLDCORE,
-		.fixed_divider = 1),
+		.fixed_divider = 1,
+		.flags = CLK_SET_RATE_PARENT),
 	[BCM2835_PLLA_PER]	= REGISTER_PLL_DIV(
 		.name = "plla_per",
 		.source_pll = "plla",
@@ -1483,7 +1485,8 @@ static const struct bcm2835_clk_desc clk
 		.a2w_reg = A2W_PLLA_PER,
 		.load_mask = CM_PLLA_LOADPER,
 		.hold_mask = CM_PLLA_HOLDPER,
-		.fixed_divider = 1),
+		.fixed_divider = 1,
+		.flags = CLK_SET_RATE_PARENT),
 	[BCM2835_PLLA_DSI0]	= REGISTER_PLL_DIV(
 		.name = "plla_dsi0",
 		.source_pll = "plla",
@@ -1499,7 +1502,8 @@ static const struct bcm2835_clk_desc clk
 		.a2w_reg = A2W_PLLA_CCP2,
 		.load_mask = CM_PLLA_LOADCCP2,
 		.hold_mask = CM_PLLA_HOLDCCP2,
-		.fixed_divider = 1),
+		.fixed_divider = 1,
+		.flags = CLK_SET_RATE_PARENT),
 
 	/* PLLB is used for the ARM's clock. */
 	[BCM2835_PLLB]		= REGISTER_PLL(
@@ -1523,7 +1527,8 @@ static const struct bcm2835_clk_desc clk
 		.a2w_reg = A2W_PLLB_ARM,
 		.load_mask = CM_PLLB_LOADARM,
 		.hold_mask = CM_PLLB_HOLDARM,
-		.fixed_divider = 1),
+		.fixed_divider = 1,
+		.flags = CLK_SET_RATE_PARENT),
 
 	/*
 	 * PLLC is the core PLL, used to drive the core VPU clock.
@@ -1552,7 +1557,8 @@ static const struct bcm2835_clk_desc clk
 		.a2w_reg = A2W_PLLC_CORE0,
 		.load_mask = CM_PLLC_LOADCORE0,
 		.hold_mask = CM_PLLC_HOLDCORE0,
-		.fixed_divider = 1),
+		.fixed_divider = 1,
+		.flags = CLK_SET_RATE_PARENT),
 	[BCM2835_PLLC_CORE1]	= REGISTER_PLL_DIV(
 		.name = "pllc_core1",
 		.source_pll = "pllc",
@@ -1560,7 +1566,8 @@ static const struct bcm2835_clk_desc clk
 		.a2w_reg = A2W_PLLC_CORE1,
 		.load_mask = CM_PLLC_LOADCORE1,
 		.hold_mask = CM_PLLC_HOLDCORE1,
-		.fixed_divider = 1),
+		.fixed_divider = 1,
+		.flags = CLK_SET_RATE_PARENT),
 	[BCM2835_PLLC_CORE2]	= REGISTER_PLL_DIV(
 		.name = "pllc_core2",
 		.source_pll = "pllc",
@@ -1568,7 +1575,8 @@ static const struct bcm2835_clk_desc clk
 		.a2w_reg = A2W_PLLC_CORE2,
 		.load_mask = CM_PLLC_LOADCORE2,
 		.hold_mask = CM_PLLC_HOLDCORE2,
-		.fixed_divider = 1),
+		.fixed_divider = 1,
+		.flags = CLK_SET_RATE_PARENT),
 	[BCM2835_PLLC_PER]	= REGISTER_PLL_DIV(
 		.name = "pllc_per",
 		.source_pll = "pllc",
@@ -1576,7 +1584,8 @@ static const struct bcm2835_clk_desc clk
 		.a2w_reg = A2W_PLLC_PER,
 		.load_mask = CM_PLLC_LOADPER,
 		.hold_mask = CM_PLLC_HOLDPER,
-		.fixed_divider = 1),
+		.fixed_divider = 1,
+		.flags = CLK_SET_RATE_PARENT),
 
 	/*
 	 * PLLD is the display PLL, used to drive DSI display panels.
@@ -1605,7 +1614,8 @@ static const struct bcm2835_clk_desc clk
 		.a2w_reg = A2W_PLLD_CORE,
 		.load_mask = CM_PLLD_LOADCORE,
 		.hold_mask = CM_PLLD_HOLDCORE,
-		.fixed_divider = 1),
+		.fixed_divider = 1,
+		.flags = CLK_SET_RATE_PARENT),
 	[BCM2835_PLLD_PER]	= REGISTER_PLL_DIV(
 		.name = "plld_per",
 		.source_pll = "plld",
@@ -1613,7 +1623,8 @@ static const struct bcm2835_clk_desc clk
 		.a2w_reg = A2W_PLLD_PER,
 		.load_mask = CM_PLLD_LOADPER,
 		.hold_mask = CM_PLLD_HOLDPER,
-		.fixed_divider = 1),
+		.fixed_divider = 1,
+		.flags = CLK_SET_RATE_PARENT),
 	[BCM2835_PLLD_DSI0]	= REGISTER_PLL_DIV(
 		.name = "plld_dsi0",
 		.source_pll = "plld",
@@ -1658,7 +1669,8 @@ static const struct bcm2835_clk_desc clk
 		.a2w_reg = A2W_PLLH_RCAL,
 		.load_mask = CM_PLLH_LOADRCAL,
 		.hold_mask = 0,
-		.fixed_divider = 10),
+		.fixed_divider = 10,
+		.flags = CLK_SET_RATE_PARENT),
 	[BCM2835_PLLH_AUX]	= REGISTER_PLL_DIV(
 		.name = "pllh_aux",
 		.source_pll = "pllh",
@@ -1666,7 +1678,8 @@ static const struct bcm2835_clk_desc clk
 		.a2w_reg = A2W_PLLH_AUX,
 		.load_mask = CM_PLLH_LOADAUX,
 		.hold_mask = 0,
-		.fixed_divider = 1),
+		.fixed_divider = 1,
+		.flags = CLK_SET_RATE_PARENT),
 	[BCM2835_PLLH_PIX]	= REGISTER_PLL_DIV(
 		.name = "pllh_pix",
 		.source_pll = "pllh",
@@ -1674,7 +1687,8 @@ static const struct bcm2835_clk_desc clk
 		.a2w_reg = A2W_PLLH_PIX,
 		.load_mask = CM_PLLH_LOADPIX,
 		.hold_mask = 0,
-		.fixed_divider = 10),
+		.fixed_divider = 10,
+		.flags = CLK_SET_RATE_PARENT),
 
 	/* the clocks */