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
|
From d839c8936020f393c5536d83b783198217243e8d Mon Sep 17 00:00:00 2001
From: Naushir Patuck <naush@raspberrypi.com>
Date: Mon, 11 May 2020 13:02:22 +0100
Subject: [PATCH] media: bcm2835: unicam: Set VPU min clock freq to
250Mhz.
When streaming with Unicam, the VPU must have a clock frequency of at
least 250Mhz. Otherwise, the input fifos could overrun, causing
image corruption.
Signed-off-by: Naushir Patuck <naush@raspberrypi.com>
---
.../media/platform/bcm2835/bcm2835-unicam.c | 49 +++++++++++++++++--
1 file changed, 44 insertions(+), 5 deletions(-)
--- a/drivers/media/platform/bcm2835/bcm2835-unicam.c
+++ b/drivers/media/platform/bcm2835/bcm2835-unicam.c
@@ -89,6 +89,11 @@ MODULE_PARM_DESC(debug, "Debug level 0-3
v4l2_err(&(dev)->v4l2_dev, fmt, ##arg)
/*
+ * Unicam must request a minimum of 250Mhz from the VPU clock.
+ * Otherwise the input FIFOs overrun and cause image corruption.
+ */
+#define MIN_VPU_CLOCK_RATE (250 * 1000 * 1000)
+/*
* To protect against a dodgy sensor driver never returning an error from
* enum_mbus_code, set a maximum index value to be used.
*/
@@ -417,8 +422,10 @@ struct unicam_device {
void __iomem *base;
/* clock gating base address */
void __iomem *clk_gate_base;
- /* clock handle */
+ /* lp clock handle */
struct clk *clock;
+ /* vpu clock handle */
+ struct clk *vpu_clock;
/* V4l2 device */
struct v4l2_device v4l2_dev;
struct media_device mdev;
@@ -1678,16 +1685,28 @@ static int unicam_start_streaming(struct
unicam_dbg(1, dev, "Running with %u data lanes\n",
dev->active_data_lanes);
- ret = clk_set_rate(dev->clock, 100 * 1000 * 1000);
+ ret = clk_set_min_rate(dev->vpu_clock, MIN_VPU_CLOCK_RATE);
+ if (ret) {
+ unicam_err(dev, "failed to set up VPU clock\n");
+ goto err_pm_put;
+ }
+
+ ret = clk_prepare_enable(dev->vpu_clock);
if (ret) {
- unicam_err(dev, "failed to set up clock\n");
+ unicam_err(dev, "Failed to enable VPU clock: %d\n", ret);
goto err_pm_put;
}
+ ret = clk_set_rate(dev->clock, 100 * 1000 * 1000);
+ if (ret) {
+ unicam_err(dev, "failed to set up CSI clock\n");
+ goto err_vpu_clock;
+ }
+
ret = clk_prepare_enable(dev->clock);
if (ret) {
unicam_err(dev, "Failed to enable CSI clock: %d\n", ret);
- goto err_pm_put;
+ goto err_vpu_clock;
}
for (i = 0; i < ARRAY_SIZE(dev->node); i++) {
@@ -1721,6 +1740,11 @@ static int unicam_start_streaming(struct
err_disable_unicam:
unicam_disable(dev);
clk_disable_unprepare(dev->clock);
+err_vpu_clock:
+ ret = clk_set_min_rate(dev->vpu_clock, 0);
+ if (ret)
+ unicam_err(dev, "failed to reset the VPU clock\n");
+ clk_disable_unprepare(dev->vpu_clock);
err_pm_put:
unicam_runtime_put(dev);
err_streaming:
@@ -1738,6 +1762,8 @@ static void unicam_stop_streaming(struct
node->streaming = false;
if (node->pad_id == IMAGE_PAD) {
+ int ret;
+
/*
* Stop streaming the sensor and disable the peripheral.
* We cannot continue streaming embedded data with the
@@ -1747,6 +1773,12 @@ static void unicam_stop_streaming(struct
unicam_err(dev, "stream off failed in subdev\n");
unicam_disable(dev);
+
+ ret = clk_set_min_rate(dev->vpu_clock, 0);
+ if (ret)
+ unicam_err(dev, "failed to reset the min VPU clock\n");
+
+ clk_disable_unprepare(dev->vpu_clock);
clk_disable_unprepare(dev->clock);
unicam_runtime_put(dev);
@@ -2750,11 +2782,18 @@ static int unicam_probe(struct platform_
unicam->clock = devm_clk_get(&pdev->dev, "lp");
if (IS_ERR(unicam->clock)) {
- unicam_err(unicam, "Failed to get clock\n");
+ unicam_err(unicam, "Failed to get lp clock\n");
ret = PTR_ERR(unicam->clock);
goto err_unicam_put;
}
+ unicam->vpu_clock = devm_clk_get(&pdev->dev, "vpu");
+ if (IS_ERR(unicam->vpu_clock)) {
+ unicam_err(unicam, "Failed to get vpu clock\n");
+ ret = PTR_ERR(unicam->vpu_clock);
+ goto err_unicam_put;
+ }
+
ret = platform_get_irq(pdev, 0);
if (ret <= 0) {
dev_err(&pdev->dev, "No IRQ resource\n");
|
