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_PHY_LED_POL_CTRL		17
 23#define MII_88E1318S_PHY_LED_TCR	18
 24#define MII_88E1318S_PHY_WOL_CTRL	16
 25#define MII_M1011_IEVENT		19
 26
 27#define MII_88E1318S_PHY_LED_TCR_INTn_ENABLE		BIT(7)
 28#define MII_88E1318S_PHY_LED_TCR_FORCE_INT		BIT(15)
 29#define MII_88E1318S_PHY_WOL_CTRL_CLEAR_WOL_STATUS	BIT(12)
 30#define LED2_FORCE_ON					(0x8 << 8)
 31#define LEDMASK						GENMASK(11,8)
 32
 33#define MII_88E1318S_PHY_LED_POL_LED2		BIT(4)
 34
 35struct power_off_cfg {
 36	char *mdio_node_name;
 37	void (*phy_set_reg)(bool restart);
 38};
 39
 40static struct phy_device *phydev;
 41static const struct power_off_cfg *cfg;
 42
 43static void linkstation_mvphy_reg_intn(bool restart)
 44{
 45	int rc = 0, saved_page;
 46	u16 data = 0;
 47
 48	if (restart)
 49		data = MII_88E1318S_PHY_LED_TCR_FORCE_INT;
 50
 51	saved_page = phy_select_page(phydev, MII_MARVELL_LED_PAGE);
 52	if (saved_page < 0)
 53		goto err;
 54
 55	/* Force manual LED2 control to let INTn work */
 56	__phy_modify(phydev, MII_PHY_LED_CTRL, LEDMASK, LED2_FORCE_ON);
 57
 58	/* Set the LED[2]/INTn pin to the required state */
 59	__phy_modify(phydev, MII_88E1318S_PHY_LED_TCR,
 60		     MII_88E1318S_PHY_LED_TCR_FORCE_INT,
 61		     MII_88E1318S_PHY_LED_TCR_INTn_ENABLE | data);
 62
 63	if (!data) {
 64		/* Clear interrupts to ensure INTn won't be holded in high state */
 65		__phy_write(phydev, MII_MARVELL_PHY_PAGE, MII_MARVELL_COPPER_PAGE);
 66		__phy_read(phydev, MII_M1011_IEVENT);
 67
 68		/* If WOL was enabled and a magic packet was received before powering
 69		 * off, we won't be able to wake up by sending another magic packet.
 70		 * Clear WOL status.
 71		 */
 72		__phy_write(phydev, MII_MARVELL_PHY_PAGE, MII_MARVELL_WOL_PAGE);
 73		__phy_set_bits(phydev, MII_88E1318S_PHY_WOL_CTRL,
 74			       MII_88E1318S_PHY_WOL_CTRL_CLEAR_WOL_STATUS);
 75	}
 76err:
 77	rc = phy_restore_page(phydev, saved_page, rc);
 78	if (rc < 0)
 79		dev_err(&phydev->mdio.dev, "Write register failed, %d\n", rc);
 80}
 81
 82static void readynas_mvphy_set_reg(bool restart)
 83{
 84	int rc = 0, saved_page;
 85	u16 data = 0;
 86
 87	if (restart)
 88		data = MII_88E1318S_PHY_LED_POL_LED2;
 89
 90	saved_page = phy_select_page(phydev, MII_MARVELL_LED_PAGE);
 91	if (saved_page < 0)
 92		goto err;
 93
 94	/* Set the LED[2].0 Polarity bit to the required state */
 95	__phy_modify(phydev, MII_PHY_LED_POL_CTRL,
 96		     MII_88E1318S_PHY_LED_POL_LED2, data);
 97
 98	if (!data) {
 99		/* If WOL was enabled and a magic packet was received before powering
100		 * off, we won't be able to wake up by sending another magic packet.
101		 * Clear WOL status.
102		 */
103		__phy_write(phydev, MII_MARVELL_PHY_PAGE, MII_MARVELL_WOL_PAGE);
104		__phy_set_bits(phydev, MII_88E1318S_PHY_WOL_CTRL,
105			       MII_88E1318S_PHY_WOL_CTRL_CLEAR_WOL_STATUS);
106	}
107err:
108	rc = phy_restore_page(phydev, saved_page, rc);
109	if (rc < 0)
110		dev_err(&phydev->mdio.dev, "Write register failed, %d\n", rc);
111}
112
113static const struct power_off_cfg linkstation_power_off_cfg = {
114	.mdio_node_name = "mdio",
115	.phy_set_reg = linkstation_mvphy_reg_intn,
116};
117
118static const struct power_off_cfg readynas_power_off_cfg = {
119	.mdio_node_name = "mdio-bus",
120	.phy_set_reg = readynas_mvphy_set_reg,
121};
122
123static int linkstation_reboot_notifier(struct notifier_block *nb,
124				       unsigned long action, void *unused)
125{
126	if (action == SYS_RESTART)
127		cfg->phy_set_reg(true);
128
129	return NOTIFY_DONE;
130}
131
132static struct notifier_block linkstation_reboot_nb = {
133	.notifier_call = linkstation_reboot_notifier,
134};
135
136static void linkstation_poweroff(void)
137{
138	unregister_reboot_notifier(&linkstation_reboot_nb);
139	cfg->phy_set_reg(false);
140
141	kernel_restart("Power off");
142}
143
144static const struct of_device_id ls_poweroff_of_match[] = {
145	{ .compatible = "buffalo,ls421d",
146	  .data = &linkstation_power_off_cfg,
147	},
148	{ .compatible = "buffalo,ls421de",
149	  .data = &linkstation_power_off_cfg,
150	},
151	{ .compatible = "netgear,readynas-duo-v2",
152	  .data = &readynas_power_off_cfg,
153	},
154	{ },
155};
156
157static int __init linkstation_poweroff_init(void)
158{
159	struct mii_bus *bus;
160	struct device_node *dn;
161	const struct of_device_id *match;
162
163	dn = of_find_matching_node(NULL, ls_poweroff_of_match);
164	if (!dn)
165		return -ENODEV;
166	of_node_put(dn);
167
168	match = of_match_node(ls_poweroff_of_match, dn);
169	cfg = match->data;
170
171	dn = of_find_node_by_name(NULL, cfg->mdio_node_name);
172	if (!dn)
173		return -ENODEV;
174
175	bus = of_mdio_find_bus(dn);
176	of_node_put(dn);
177	if (!bus)
178		return -EPROBE_DEFER;
179
180	phydev = phy_find_first(bus);
181	put_device(&bus->dev);
182	if (!phydev)
183		return -EPROBE_DEFER;
184
185	register_reboot_notifier(&linkstation_reboot_nb);
186	pm_power_off = linkstation_poweroff;
187
188	return 0;
189}
190
191static void __exit linkstation_poweroff_exit(void)
192{
193	pm_power_off = NULL;
194	unregister_reboot_notifier(&linkstation_reboot_nb);
195}
196
197module_init(linkstation_poweroff_init);
198module_exit(linkstation_poweroff_exit);
199
200MODULE_AUTHOR("Daniel González Cabanelas <dgcbueu@gmail.com>");
201MODULE_DESCRIPTION("LinkStation power off driver");
202MODULE_LICENSE("GPL v2");