1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Board-level suspend/resume support. |
4 | * |
5 | * Copyright (C) 2014-2015 Marvell |
6 | * |
7 | * Thomas Petazzoni <thomas.petazzoni@free-electrons.com> |
8 | */ |
9 | |
10 | #include <linux/delay.h> |
11 | #include <linux/err.h> |
12 | #include <linux/gpio/consumer.h> |
13 | #include <linux/init.h> |
14 | #include <linux/io.h> |
15 | #include <linux/of.h> |
16 | #include <linux/of_address.h> |
17 | #include <linux/slab.h> |
18 | #include "common.h" |
19 | |
20 | #define ARMADA_PIC_NR_GPIOS 3 |
21 | |
22 | static void __iomem *gpio_ctrl; |
23 | static struct gpio_desc *pic_gpios[ARMADA_PIC_NR_GPIOS]; |
24 | static int pic_raw_gpios[ARMADA_PIC_NR_GPIOS]; |
25 | |
26 | static void mvebu_armada_pm_enter(void __iomem *sdram_reg, u32 srcmd) |
27 | { |
28 | u32 reg, ackcmd; |
29 | int i; |
30 | |
31 | /* Put 001 as value on the GPIOs */ |
32 | reg = readl(addr: gpio_ctrl); |
33 | for (i = 0; i < ARMADA_PIC_NR_GPIOS; i++) |
34 | reg &= ~BIT(pic_raw_gpios[i]); |
35 | reg |= BIT(pic_raw_gpios[0]); |
36 | writel(val: reg, addr: gpio_ctrl); |
37 | |
38 | /* Prepare writing 111 to the GPIOs */ |
39 | ackcmd = readl(addr: gpio_ctrl); |
40 | for (i = 0; i < ARMADA_PIC_NR_GPIOS; i++) |
41 | ackcmd |= BIT(pic_raw_gpios[i]); |
42 | |
43 | srcmd = cpu_to_le32(srcmd); |
44 | ackcmd = cpu_to_le32(ackcmd); |
45 | |
46 | /* |
47 | * Wait a while, the PIC needs quite a bit of time between the |
48 | * two GPIO commands. |
49 | */ |
50 | mdelay(3000); |
51 | |
52 | asm volatile ( |
53 | /* Align to a cache line */ |
54 | ".balign 32\n\t" |
55 | |
56 | /* Enter self refresh */ |
57 | "str %[srcmd], [%[sdram_reg]]\n\t" |
58 | |
59 | /* |
60 | * Wait 100 cycles for DDR to enter self refresh, by |
61 | * doing 50 times two instructions. |
62 | */ |
63 | "mov r1, #50\n\t" |
64 | "1: subs r1, r1, #1\n\t" |
65 | "bne 1b\n\t" |
66 | |
67 | /* Issue the command ACK */ |
68 | "str %[ackcmd], [%[gpio_ctrl]]\n\t" |
69 | |
70 | /* Trap the processor */ |
71 | "b .\n\t" |
72 | : : [srcmd] "r" (srcmd), [sdram_reg] "r" (sdram_reg), |
73 | [ackcmd] "r" (ackcmd), [gpio_ctrl] "r" (gpio_ctrl) : "r1" ); |
74 | } |
75 | |
76 | static int __init mvebu_armada_pm_init(void) |
77 | { |
78 | struct device_node *np; |
79 | struct device_node *gpio_ctrl_np = NULL; |
80 | int ret = 0, i; |
81 | |
82 | if (!of_machine_is_compatible(compat: "marvell,axp-gp" )) |
83 | return -ENODEV; |
84 | |
85 | np = of_find_node_by_name(NULL, name: "pm_pic" ); |
86 | if (!np) |
87 | return -ENODEV; |
88 | |
89 | for (i = 0; i < ARMADA_PIC_NR_GPIOS; i++) { |
90 | char *name; |
91 | struct of_phandle_args args; |
92 | |
93 | name = kasprintf(GFP_KERNEL, fmt: "pic-pin%d" , i); |
94 | if (!name) { |
95 | ret = -ENOMEM; |
96 | goto out; |
97 | } |
98 | |
99 | pic_gpios[i] = fwnode_gpiod_get_index(of_fwnode_handle(np), |
100 | con_id: "ctrl" , index: i, flags: GPIOD_OUT_HIGH, |
101 | label: name); |
102 | ret = PTR_ERR_OR_ZERO(ptr: pic_gpios[i]); |
103 | if (ret) { |
104 | kfree(objp: name); |
105 | goto out; |
106 | } |
107 | |
108 | ret = of_parse_phandle_with_fixed_args(np, list_name: "ctrl-gpios" , cell_count: 2, |
109 | index: i, out_args: &args); |
110 | if (ret < 0) { |
111 | gpiod_put(desc: pic_gpios[i]); |
112 | kfree(objp: name); |
113 | goto out; |
114 | } |
115 | |
116 | if (gpio_ctrl_np) |
117 | of_node_put(node: gpio_ctrl_np); |
118 | gpio_ctrl_np = args.np; |
119 | pic_raw_gpios[i] = args.args[0]; |
120 | } |
121 | |
122 | gpio_ctrl = of_iomap(node: gpio_ctrl_np, index: 0); |
123 | if (!gpio_ctrl) { |
124 | ret = -ENOMEM; |
125 | goto out; |
126 | } |
127 | |
128 | mvebu_pm_suspend_init(board_pm_enter: mvebu_armada_pm_enter); |
129 | |
130 | out: |
131 | of_node_put(node: np); |
132 | of_node_put(node: gpio_ctrl_np); |
133 | return ret; |
134 | } |
135 | |
136 | /* |
137 | * Registering the mvebu_board_pm_enter callback must be done before |
138 | * the platform_suspend_ops will be registered. In the same time we |
139 | * also need to have the gpio devices registered. That's why we use a |
140 | * device_initcall_sync which is called after all the device_initcall |
141 | * (used by the gpio device) but before the late_initcall (used to |
142 | * register the platform_suspend_ops) |
143 | */ |
144 | device_initcall_sync(mvebu_armada_pm_init); |
145 | |