xref: /openbmc/u-boot/arch/arm/mach-tegra/powergate.c (revision e30d2bd4)
1 /*
2  * Copyright (c) 2014, NVIDIA CORPORATION.  All rights reserved.
3  *
4  * SPDX-License-Identifier: GPL-2.0
5  */
6 
7 #include <common.h>
8 #include <errno.h>
9 
10 #include <asm/io.h>
11 #include <asm/types.h>
12 #include <asm/arch/flow.h>
13 #include <asm/arch/powergate.h>
14 #include <asm/arch/tegra.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 
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 = readl(NV_PA_PMC_BASE + PWRGATE_STATUS);
29 	old_mask = value & (1 << id);
30 
31 	if (mask == old_mask)
32 		return 0;
33 
34 	writel(PWRGATE_TOGGLE_START | id, NV_PA_PMC_BASE + PWRGATE_TOGGLE);
35 
36 	start = get_timer(0);
37 
38 	while (get_timer(start) < timeout) {
39 		value = readl(NV_PA_PMC_BASE + PWRGATE_STATUS);
40 		if ((value & (1 << id)) == mask)
41 			return 0;
42 	}
43 
44 	return -ETIMEDOUT;
45 }
46 
47 int tegra_powergate_power_on(enum tegra_powergate id)
48 {
49 	return tegra_powergate_set(id, true);
50 }
51 
52 int tegra_powergate_power_off(enum tegra_powergate id)
53 {
54 	return tegra_powergate_set(id, false);
55 }
56 
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 	writel(value, NV_PA_PMC_BASE + REMOVE_CLAMPING);
74 
75 	return 0;
76 }
77 
78 static void tegra_powergate_ram_repair(void)
79 {
80 #ifdef CONFIG_TEGRA124
81 	struct flow_ctlr *flow = (struct flow_ctlr *)NV_PA_FLOW_BASE;
82 
83 	/* Request RAM repair for cluster 0 and wait until complete */
84 	setbits_le32(&flow->ram_repair, RAM_REPAIR_REQ);
85 	while (!(readl(&flow->ram_repair) & RAM_REPAIR_STS))
86 		;
87 
88 	/* Same for cluster 1 */
89 	setbits_le32(&flow->ram_repair_cluster1, RAM_REPAIR_REQ);
90 	while (!(readl(&flow->ram_repair_cluster1) & RAM_REPAIR_STS))
91 		;
92 #endif
93 }
94 
95 int tegra_powergate_sequence_power_up(enum tegra_powergate id,
96 				      enum periph_id periph)
97 {
98 	int err;
99 
100 	tegra_powergate_ram_repair();
101 	reset_set_enable(periph, 1);
102 
103 	err = tegra_powergate_power_on(id);
104 	if (err < 0)
105 		return err;
106 
107 	clock_enable(periph);
108 
109 	udelay(10);
110 
111 	err = tegra_powergate_remove_clamping(id);
112 	if (err < 0)
113 		return err;
114 
115 	udelay(10);
116 
117 	reset_set_enable(periph, 0);
118 
119 	return 0;
120 }
121