1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Copyright (C) 2018 Spreadtrum Communications Inc.
4*4882a593Smuzhiyun * Copyright (C) 2018 Linaro Ltd.
5*4882a593Smuzhiyun */
6*4882a593Smuzhiyun
7*4882a593Smuzhiyun #include <linux/cpu.h>
8*4882a593Smuzhiyun #include <linux/kernel.h>
9*4882a593Smuzhiyun #include <linux/module.h>
10*4882a593Smuzhiyun #include <linux/platform_device.h>
11*4882a593Smuzhiyun #include <linux/pm.h>
12*4882a593Smuzhiyun #include <linux/regmap.h>
13*4882a593Smuzhiyun #include <linux/syscore_ops.h>
14*4882a593Smuzhiyun
15*4882a593Smuzhiyun #define SC27XX_PWR_PD_HW 0xc2c
16*4882a593Smuzhiyun #define SC27XX_PWR_OFF_EN BIT(0)
17*4882a593Smuzhiyun #define SC27XX_SLP_CTRL 0xdf0
18*4882a593Smuzhiyun #define SC27XX_LDO_XTL_EN BIT(3)
19*4882a593Smuzhiyun
20*4882a593Smuzhiyun static struct regmap *regmap;
21*4882a593Smuzhiyun
22*4882a593Smuzhiyun /*
23*4882a593Smuzhiyun * On Spreadtrum platform, we need power off system through external SC27xx
24*4882a593Smuzhiyun * series PMICs, and it is one similar SPI bus mapped by regmap to access PMIC,
25*4882a593Smuzhiyun * which is not fast io access.
26*4882a593Smuzhiyun *
27*4882a593Smuzhiyun * So before stopping other cores, we need release other cores' resource by
28*4882a593Smuzhiyun * taking cpus down to avoid racing regmap or spi mutex lock when poweroff
29*4882a593Smuzhiyun * system through PMIC.
30*4882a593Smuzhiyun */
sc27xx_poweroff_shutdown(void)31*4882a593Smuzhiyun static void sc27xx_poweroff_shutdown(void)
32*4882a593Smuzhiyun {
33*4882a593Smuzhiyun #ifdef CONFIG_HOTPLUG_CPU
34*4882a593Smuzhiyun int cpu;
35*4882a593Smuzhiyun
36*4882a593Smuzhiyun for_each_online_cpu(cpu) {
37*4882a593Smuzhiyun if (cpu != smp_processor_id())
38*4882a593Smuzhiyun remove_cpu(cpu);
39*4882a593Smuzhiyun }
40*4882a593Smuzhiyun #endif
41*4882a593Smuzhiyun }
42*4882a593Smuzhiyun
43*4882a593Smuzhiyun static struct syscore_ops poweroff_syscore_ops = {
44*4882a593Smuzhiyun .shutdown = sc27xx_poweroff_shutdown,
45*4882a593Smuzhiyun };
46*4882a593Smuzhiyun
sc27xx_poweroff_do_poweroff(void)47*4882a593Smuzhiyun static void sc27xx_poweroff_do_poweroff(void)
48*4882a593Smuzhiyun {
49*4882a593Smuzhiyun /* Disable the external subsys connection's power firstly */
50*4882a593Smuzhiyun regmap_write(regmap, SC27XX_SLP_CTRL, SC27XX_LDO_XTL_EN);
51*4882a593Smuzhiyun
52*4882a593Smuzhiyun regmap_write(regmap, SC27XX_PWR_PD_HW, SC27XX_PWR_OFF_EN);
53*4882a593Smuzhiyun }
54*4882a593Smuzhiyun
sc27xx_poweroff_probe(struct platform_device * pdev)55*4882a593Smuzhiyun static int sc27xx_poweroff_probe(struct platform_device *pdev)
56*4882a593Smuzhiyun {
57*4882a593Smuzhiyun if (regmap)
58*4882a593Smuzhiyun return -EINVAL;
59*4882a593Smuzhiyun
60*4882a593Smuzhiyun regmap = dev_get_regmap(pdev->dev.parent, NULL);
61*4882a593Smuzhiyun if (!regmap)
62*4882a593Smuzhiyun return -ENODEV;
63*4882a593Smuzhiyun
64*4882a593Smuzhiyun pm_power_off = sc27xx_poweroff_do_poweroff;
65*4882a593Smuzhiyun register_syscore_ops(&poweroff_syscore_ops);
66*4882a593Smuzhiyun return 0;
67*4882a593Smuzhiyun }
68*4882a593Smuzhiyun
69*4882a593Smuzhiyun static struct platform_driver sc27xx_poweroff_driver = {
70*4882a593Smuzhiyun .probe = sc27xx_poweroff_probe,
71*4882a593Smuzhiyun .driver = {
72*4882a593Smuzhiyun .name = "sc27xx-poweroff",
73*4882a593Smuzhiyun },
74*4882a593Smuzhiyun };
75*4882a593Smuzhiyun module_platform_driver(sc27xx_poweroff_driver);
76*4882a593Smuzhiyun
77*4882a593Smuzhiyun MODULE_DESCRIPTION("Power off driver for SC27XX PMIC Device");
78*4882a593Smuzhiyun MODULE_AUTHOR("Baolin Wang <baolin.wang@unisoc.com>");
79*4882a593Smuzhiyun MODULE_LICENSE("GPL v2");
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