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_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
  32 static struct phy_device *phydev;
  33
  34 static 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         }
  63 err:
  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
  69 static 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
  78 static struct notifier_block linkstation_reboot_nb = {
  79         .notifier_call = linkstation_reboot_notifier,
  80 };
  81
  82 static 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
  90 static const struct of_device_id ls_poweroff_of_match[] = {
  91         { .compatible = "buffalo,ls421d" },
  92         { .compatible = "buffalo,ls421de" },
  93         { },
  94 };
  95
  96 static 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
 125 static void __exit linkstation_poweroff_exit(void)
 126 {
 127         pm_power_off = NULL;
 128         unregister_reboot_notifier(&linkstation_reboot_nb);
 129 }
 130
 131 module_init(linkstation_poweroff_init);
 132 module_exit(linkstation_poweroff_exit);
 133
 134 MODULE_AUTHOR("Daniel González Cabanelas <dgcbueu@gmail.com>");
 135 MODULE_DESCRIPTION("LinkStation power off driver");
 136 MODULE_LICENSE("GPL v2");