drivers/power/reset/linkstation-poweroff.c

   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
  35 struct power_off_cfg {
  36         char *mdio_node_name;
  37         void (*phy_set_reg)(bool restart);
  38 };
  39
  40 static struct phy_device *phydev;
  41 static const struct power_off_cfg *cfg;
  42
  43 static 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         }
  76 err:
  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
  82 static 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         }
 107 err:
 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
 113 static const struct power_off_cfg linkstation_power_off_cfg = {
 114         .mdio_node_name = "mdio",
 115         .phy_set_reg = linkstation_mvphy_reg_intn,
 116 };
 117
 118 static 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
 123 static 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
 132 static struct notifier_block linkstation_reboot_nb = {
 133         .notifier_call = linkstation_reboot_notifier,
 134 };
 135
 136 static 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
 144 static 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
 157 static 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
 191 static void __exit linkstation_poweroff_exit(void)
 192 {
 193         pm_power_off = NULL;
 194         unregister_reboot_notifier(&linkstation_reboot_nb);
 195 }
 196
 197 module_init(linkstation_poweroff_init);
 198 module_exit(linkstation_poweroff_exit);
 199
 200 MODULE_AUTHOR("Daniel González Cabanelas <dgcbueu@gmail.com>");
 201 MODULE_DESCRIPTION("LinkStation power off driver");
 202 MODULE_LICENSE("GPL v2");