1// SPDX-License-Identifier: GPL-2.0
2/*
3 * LinkStation power off restart driver
4 * Copyright (C) 2020 Daniel González Cabanelas <dgcbueu@gmail.com>
5 */
6
7#include <linux/module.h>
8#include <linux/notifier.h>
9#include <linux/of.h>
10#include <linux/of_mdio.h>
11#include <linux/of_platform.h>
12#include <linux/reboot.h>
13#include <linux/phy.h>
14
15/* Defines from the eth phy Marvell driver */
16#define MII_MARVELL_COPPER_PAGE		0
17#define MII_MARVELL_LED_PAGE		3
18#define MII_MARVELL_WOL_PAGE		17
19#define MII_MARVELL_PHY_PAGE		22
20
21#define MII_PHY_LED_CTRL		16
22#define MII_88E1318S_PHY_LED_TCR	18
23#define MII_88E1318S_PHY_WOL_CTRL	16
24#define MII_M1011_IEVENT		19
25
26#define MII_88E1318S_PHY_LED_TCR_INTn_ENABLE		BIT(7)
27#define MII_88E1318S_PHY_LED_TCR_FORCE_INT		BIT(15)
28#define MII_88E1318S_PHY_WOL_CTRL_CLEAR_WOL_STATUS	BIT(12)
29#define LED2_FORCE_ON					(0x8 << 8)
30#define LEDMASK						GENMASK(11,8)
31
32static struct phy_device *phydev;
33
34static void mvphy_reg_intn(u16 data)
35{
36	int rc = 0, saved_page;
37
38	saved_page = phy_select_page(phydev, MII_MARVELL_LED_PAGE);
39	if (saved_page < 0)
40		goto err;
41
42	/* Force manual LED2 control to let INTn work */
43	__phy_modify(phydev, MII_PHY_LED_CTRL, LEDMASK, LED2_FORCE_ON);
44
45	/* Set the LED[2]/INTn pin to the required state */
46	__phy_modify(phydev, MII_88E1318S_PHY_LED_TCR,
47		     MII_88E1318S_PHY_LED_TCR_FORCE_INT,
48		     MII_88E1318S_PHY_LED_TCR_INTn_ENABLE | data);
49
50	if (!data) {
51		/* Clear interrupts to ensure INTn won't be holded in high state */
52		__phy_write(phydev, MII_MARVELL_PHY_PAGE, MII_MARVELL_COPPER_PAGE);
53		__phy_read(phydev, MII_M1011_IEVENT);
54
55		/* If WOL was enabled and a magic packet was received before powering
56		 * off, we won't be able to wake up by sending another magic packet.
57		 * Clear WOL status.
58		 */
59		__phy_write(phydev, MII_MARVELL_PHY_PAGE, MII_MARVELL_WOL_PAGE);
60		__phy_set_bits(phydev, MII_88E1318S_PHY_WOL_CTRL,
61			       MII_88E1318S_PHY_WOL_CTRL_CLEAR_WOL_STATUS);
62	}
63err:
64	rc = phy_restore_page(phydev, saved_page, rc);
65	if (rc < 0)
66		dev_err(&phydev->mdio.dev, "Write register failed, %d\n", rc);
67}
68
69static int linkstation_reboot_notifier(struct notifier_block *nb,
70				       unsigned long action, void *unused)
71{
72	if (action == SYS_RESTART)
73		mvphy_reg_intn(MII_88E1318S_PHY_LED_TCR_FORCE_INT);
74
75	return NOTIFY_DONE;
76}
77
78static struct notifier_block linkstation_reboot_nb = {
79	.notifier_call = linkstation_reboot_notifier,
80};
81
82static void linkstation_poweroff(void)
83{
84	unregister_reboot_notifier(&linkstation_reboot_nb);
85	mvphy_reg_intn(0);
86
87	kernel_restart("Power off");
88}
89
90static const struct of_device_id ls_poweroff_of_match[] = {
91	{ .compatible = "buffalo,ls421d" },
92	{ .compatible = "buffalo,ls421de" },
93	{ },
94};
95
96static int __init linkstation_poweroff_init(void)
97{
98	struct mii_bus *bus;
99	struct device_node *dn;
100
101	dn = of_find_matching_node(NULL, ls_poweroff_of_match);
102	if (!dn)
103		return -ENODEV;
104	of_node_put(dn);
105
106	dn = of_find_node_by_name(NULL, "mdio");
107	if (!dn)
108		return -ENODEV;
109
110	bus = of_mdio_find_bus(dn);
111	of_node_put(dn);
112	if (!bus)
113		return -EPROBE_DEFER;
114
115	phydev = phy_find_first(bus);
116	if (!phydev)
117		return -EPROBE_DEFER;
118
119	register_reboot_notifier(&linkstation_reboot_nb);
120	pm_power_off = linkstation_poweroff;
121
122	return 0;
123}
124
125static void __exit linkstation_poweroff_exit(void)
126{
127	pm_power_off = NULL;
128	unregister_reboot_notifier(&linkstation_reboot_nb);
129}
130
131module_init(linkstation_poweroff_init);
132module_exit(linkstation_poweroff_exit);
133
134MODULE_AUTHOR("Daniel González Cabanelas <dgcbueu@gmail.com>");
135MODULE_DESCRIPTION("LinkStation power off driver");
136MODULE_LICENSE("GPL v2");
137