2 * Board-level suspend/resume support.
4 * Copyright (C) 2014-2015 Marvell
6 * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
8 * This file is licensed under the terms of the GNU General Public
9 * License version 2. This program is licensed "as is" without any
10 * warranty of any kind, whether express or implied.
13 #include <linux/delay.h>
14 #include <linux/gpio.h>
15 #include <linux/init.h>
18 #include <linux/of_address.h>
19 #include <linux/of_gpio.h>
20 #include <linux/slab.h>
23 #define ARMADA_PIC_NR_GPIOS 3
25 static void __iomem *gpio_ctrl;
26 static int pic_gpios[ARMADA_PIC_NR_GPIOS];
27 static int pic_raw_gpios[ARMADA_PIC_NR_GPIOS];
29 static void mvebu_armada_pm_enter(void __iomem *sdram_reg, u32 srcmd)
34 /* Put 001 as value on the GPIOs */
35 reg = readl(gpio_ctrl);
36 for (i = 0; i < ARMADA_PIC_NR_GPIOS; i++)
37 reg &= ~BIT(pic_raw_gpios[i]);
38 reg |= BIT(pic_raw_gpios[0]);
39 writel(reg, gpio_ctrl);
41 /* Prepare writing 111 to the GPIOs */
42 ackcmd = readl(gpio_ctrl);
43 for (i = 0; i < ARMADA_PIC_NR_GPIOS; i++)
44 ackcmd |= BIT(pic_raw_gpios[i]);
46 srcmd = cpu_to_le32(srcmd);
47 ackcmd = cpu_to_le32(ackcmd);
50 * Wait a while, the PIC needs quite a bit of time between the
56 /* Align to a cache line */
59 /* Enter self refresh */
60 "str %[srcmd], [%[sdram_reg]]\n\t"
63 * Wait 100 cycles for DDR to enter self refresh, by
64 * doing 50 times two instructions.
67 "1: subs r1, r1, #1\n\t"
70 /* Issue the command ACK */
71 "str %[ackcmd], [%[gpio_ctrl]]\n\t"
73 /* Trap the processor */
75 : : [srcmd] "r" (srcmd), [sdram_reg] "r" (sdram_reg),
76 [ackcmd] "r" (ackcmd), [gpio_ctrl] "r" (gpio_ctrl) : "r1");
79 static int __init mvebu_armada_pm_init(void)
81 struct device_node *np;
82 struct device_node *gpio_ctrl_np = NULL;
85 if (!of_machine_is_compatible("marvell,axp-gp"))
88 np = of_find_node_by_name(NULL, "pm_pic");
92 for (i = 0; i < ARMADA_PIC_NR_GPIOS; i++) {
94 struct of_phandle_args args;
96 pic_gpios[i] = of_get_named_gpio(np, "ctrl-gpios", i);
97 if (pic_gpios[i] < 0) {
102 name = kasprintf(GFP_KERNEL, "pic-pin%d", i);
108 ret = gpio_request(pic_gpios[i], name);
114 ret = gpio_direction_output(pic_gpios[i], 0);
116 gpio_free(pic_gpios[i]);
121 ret = of_parse_phandle_with_fixed_args(np, "ctrl-gpios", 2,
124 gpio_free(pic_gpios[i]);
130 of_node_put(gpio_ctrl_np);
131 gpio_ctrl_np = args.np;
132 pic_raw_gpios[i] = args.args[0];
135 gpio_ctrl = of_iomap(gpio_ctrl_np, 0);
141 mvebu_pm_suspend_init(mvebu_armada_pm_enter);
145 of_node_put(gpio_ctrl_np);
150 * Registering the mvebu_board_pm_enter callback must be done before
151 * the platform_suspend_ops will be registered. In the same time we
152 * also need to have the gpio devices registered. That's why we use a
153 * device_initcall_sync which is called after all the device_initcall
154 * (used by the gpio device) but before the late_initcall (used to
155 * register the platform_suspend_ops)
157 device_initcall_sync(mvebu_armada_pm_init);