1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (c) 2014-2019, 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 #include <asm/arch-tegra/pmc.h>
15
16 #define PWRGATE_TOGGLE 0x30
17 #define PWRGATE_TOGGLE_START (1 << 8)
18
19 #define REMOVE_CLAMPING 0x34
20
21 #define PWRGATE_STATUS 0x38
22
tegra_powergate_set(enum tegra_powergate id,bool state)23 static int tegra_powergate_set(enum tegra_powergate id, bool state)
24 {
25 u32 value, mask = state ? (1 << id) : 0, old_mask;
26 unsigned long start, timeout = 25;
27
28 value = tegra_pmc_readl(PWRGATE_STATUS);
29 old_mask = value & (1 << id);
30
31 if (mask == old_mask)
32 return 0;
33
34 tegra_pmc_writel(PWRGATE_TOGGLE_START | id, PWRGATE_TOGGLE);
35
36 start = get_timer(0);
37
38 while (get_timer(start) < timeout) {
39 value = tegra_pmc_readl(PWRGATE_STATUS);
40 if ((value & (1 << id)) == mask)
41 return 0;
42 }
43
44 return -ETIMEDOUT;
45 }
46
tegra_powergate_power_on(enum tegra_powergate id)47 int tegra_powergate_power_on(enum tegra_powergate id)
48 {
49 return tegra_powergate_set(id, true);
50 }
51
tegra_powergate_power_off(enum tegra_powergate id)52 int tegra_powergate_power_off(enum tegra_powergate id)
53 {
54 return tegra_powergate_set(id, false);
55 }
56
tegra_powergate_remove_clamping(enum tegra_powergate id)57 static int tegra_powergate_remove_clamping(enum tegra_powergate id)
58 {
59 unsigned long value;
60
61 /*
62 * The REMOVE_CLAMPING register has the bits for the PCIE and VDEC
63 * partitions reversed. This was originally introduced on Tegra20 but
64 * has since been carried forward for backwards-compatibility.
65 */
66 if (id == TEGRA_POWERGATE_VDEC)
67 value = 1 << TEGRA_POWERGATE_PCIE;
68 else if (id == TEGRA_POWERGATE_PCIE)
69 value = 1 << TEGRA_POWERGATE_VDEC;
70 else
71 value = 1 << id;
72
73 tegra_pmc_writel(value, REMOVE_CLAMPING);
74
75 return 0;
76 }
77
tegra_powergate_sequence_power_up(enum tegra_powergate id,enum periph_id periph)78 int tegra_powergate_sequence_power_up(enum tegra_powergate id,
79 enum periph_id periph)
80 {
81 int err;
82
83 reset_set_enable(periph, 1);
84
85 err = tegra_powergate_power_on(id);
86 if (err < 0)
87 return err;
88
89 clock_enable(periph);
90
91 udelay(10);
92
93 err = tegra_powergate_remove_clamping(id);
94 if (err < 0)
95 return err;
96
97 udelay(10);
98
99 reset_set_enable(periph, 0);
100
101 return 0;
102 }
103