1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (c) 2014, NVIDIA CORPORATION. All rights reserved.
4 */
5
6 #include <common.h>
7 #include <errno.h>
8
9 #include <asm/io.h>
10 #include <asm/types.h>
11
12 #include <asm/arch/powergate.h>
13 #include <asm/arch/tegra.h>
14
15 #define PWRGATE_TOGGLE 0x30
16 #define PWRGATE_TOGGLE_START (1 << 8)
17
18 #define REMOVE_CLAMPING 0x34
19
20 #define PWRGATE_STATUS 0x38
21
tegra_powergate_set(enum tegra_powergate id,bool state)22 static int tegra_powergate_set(enum tegra_powergate id, bool state)
23 {
24 u32 value, mask = state ? (1 << id) : 0, old_mask;
25 unsigned long start, timeout = 25;
26
27 value = readl(NV_PA_PMC_BASE + PWRGATE_STATUS);
28 old_mask = value & (1 << id);
29
30 if (mask == old_mask)
31 return 0;
32
33 writel(PWRGATE_TOGGLE_START | id, NV_PA_PMC_BASE + PWRGATE_TOGGLE);
34
35 start = get_timer(0);
36
37 while (get_timer(start) < timeout) {
38 value = readl(NV_PA_PMC_BASE + PWRGATE_STATUS);
39 if ((value & (1 << id)) == mask)
40 return 0;
41 }
42
43 return -ETIMEDOUT;
44 }
45
tegra_powergate_power_on(enum tegra_powergate id)46 int tegra_powergate_power_on(enum tegra_powergate id)
47 {
48 return tegra_powergate_set(id, true);
49 }
50
tegra_powergate_power_off(enum tegra_powergate id)51 int tegra_powergate_power_off(enum tegra_powergate id)
52 {
53 return tegra_powergate_set(id, false);
54 }
55
tegra_powergate_remove_clamping(enum tegra_powergate id)56 static int tegra_powergate_remove_clamping(enum tegra_powergate id)
57 {
58 unsigned long value;
59
60 /*
61 * The REMOVE_CLAMPING register has the bits for the PCIE and VDEC
62 * partitions reversed. This was originally introduced on Tegra20 but
63 * has since been carried forward for backwards-compatibility.
64 */
65 if (id == TEGRA_POWERGATE_VDEC)
66 value = 1 << TEGRA_POWERGATE_PCIE;
67 else if (id == TEGRA_POWERGATE_PCIE)
68 value = 1 << TEGRA_POWERGATE_VDEC;
69 else
70 value = 1 << id;
71
72 writel(value, NV_PA_PMC_BASE + REMOVE_CLAMPING);
73
74 return 0;
75 }
76
tegra_powergate_sequence_power_up(enum tegra_powergate id,enum periph_id periph)77 int tegra_powergate_sequence_power_up(enum tegra_powergate id,
78 enum periph_id periph)
79 {
80 int err;
81
82 reset_set_enable(periph, 1);
83
84 err = tegra_powergate_power_on(id);
85 if (err < 0)
86 return err;
87
88 clock_enable(periph);
89
90 udelay(10);
91
92 err = tegra_powergate_remove_clamping(id);
93 if (err < 0)
94 return err;
95
96 udelay(10);
97
98 reset_set_enable(periph, 0);
99
100 return 0;
101 }
102