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

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