target/linux/generic/backport-5.4/025-power-reset-add-driver-for-LinkStation-power-off.patch

   1 From a7f79f99541eff4e6bcae0014eb08d3019337565 Mon Sep 17 00:00:00 2001
   2 From: =?UTF-8?q?Daniel=20Gonz=C3=A1lez=20Cabanelas?= <dgcbueu@gmail.com>
   3 Date: Wed, 15 Jul 2020 15:35:14 +0200
   4 Subject: [PATCH] power: reset: add driver for LinkStation power off
   5 MIME-Version: 1.0
   6 Content-Type: text/plain; charset=UTF-8
   7 Content-Transfer-Encoding: 8bit
   8
   9 Some Buffalo LinkStations perform the power off operation, at restart
  10 time, depending on the state of an output pin (LED2/INTn) at the ethernet
  11 PHY. This pin is also used to wake the machine when a WoL packet is
  12 received by the PHY.
  13
  14 The driver is required by the Buffalo LinkStation LS421DE (ARM MVEBU),
  15 and other models. Without it, the board remains forever halted if a
  16 power off command is executed, unless the PSU is disconnected and
  17 connected again.
  18
  19 Add the driver to provide the power off function and also make the WoL
  20 feature to be available.
  21
  22 Signed-off-by: Daniel González Cabanelas <dgcbueu@gmail.com>
  23 Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
  24 ---
  25  drivers/power/reset/Kconfig                |  11 ++
  26  drivers/power/reset/Makefile               |   1 +
  27  drivers/power/reset/linkstation-poweroff.c | 136 +++++++++++++++++++++
  28  3 files changed, 148 insertions(+)
  29  create mode 100644 drivers/power/reset/linkstation-poweroff.c
  30
  31 --- a/drivers/power/reset/Kconfig
  32 +++ b/drivers/power/reset/Kconfig
  33 @@ -99,6 +99,17 @@ config POWER_RESET_HISI
  34         help
  35           Reboot support for Hisilicon boards.
  36
  37 +config POWER_RESET_LINKSTATION
  38 +       tristate "Buffalo LinkStation power-off driver"
  39 +       depends on ARCH_MVEBU || COMPILE_TEST
  40 +       depends on OF_MDIO && PHYLIB
  41 +       help
  42 +         This driver supports turning off some Buffalo LinkStations by
  43 +         setting an output pin at the ethernet PHY to the correct state.
  44 +         It also makes the device compatible with the WoL function.
  45 +
  46 +         Say Y here if you have a Buffalo LinkStation LS421D/E.
  47 +
  48  config POWER_RESET_MSM
  49         bool "Qualcomm MSM power-off driver"
  50         depends on ARCH_QCOM
  51 --- a/drivers/power/reset/Makefile
  52 +++ b/drivers/power/reset/Makefile
  53 @@ -10,6 +10,7 @@ obj-$(CONFIG_POWER_RESET_GEMINI_POWEROFF
  54  obj-$(CONFIG_POWER_RESET_GPIO) += gpio-poweroff.o
  55  obj-$(CONFIG_POWER_RESET_GPIO_RESTART) += gpio-restart.o
  56  obj-$(CONFIG_POWER_RESET_HISI) += hisi-reboot.o
  57 +obj-${CONFIG_POWER_RESET_LINKSTATION} += linkstation-poweroff.o
  58  obj-$(CONFIG_POWER_RESET_MSM) += msm-poweroff.o
  59  obj-$(CONFIG_POWER_RESET_QCOM_PON) += qcom-pon.o
  60  obj-$(CONFIG_POWER_RESET_OCELOT_RESET) += ocelot-reset.o
  61 --- /dev/null
  62 +++ b/drivers/power/reset/linkstation-poweroff.c
  63 @@ -0,0 +1,136 @@
  64 +// SPDX-License-Identifier: GPL-2.0
  65 +/*
  66 + * LinkStation power off restart driver
  67 + * Copyright (C) 2020 Daniel González Cabanelas <dgcbueu@gmail.com>
  68 + */
  69 +
  70 +#include <linux/module.h>
  71 +#include <linux/notifier.h>
  72 +#include <linux/of.h>
  73 +#include <linux/of_mdio.h>
  74 +#include <linux/of_platform.h>
  75 +#include <linux/reboot.h>
  76 +#include <linux/phy.h>
  77 +
  78 +/* Defines from the eth phy Marvell driver */
  79 +#define MII_MARVELL_COPPER_PAGE                0
  80 +#define MII_MARVELL_LED_PAGE           3
  81 +#define MII_MARVELL_WOL_PAGE           17
  82 +#define MII_MARVELL_PHY_PAGE           22
  83 +
  84 +#define MII_PHY_LED_CTRL               16
  85 +#define MII_88E1318S_PHY_LED_TCR       18
  86 +#define MII_88E1318S_PHY_WOL_CTRL      16
  87 +#define MII_M1011_IEVENT               19
  88 +
  89 +#define MII_88E1318S_PHY_LED_TCR_INTn_ENABLE           BIT(7)
  90 +#define MII_88E1318S_PHY_LED_TCR_FORCE_INT             BIT(15)
  91 +#define MII_88E1318S_PHY_WOL_CTRL_CLEAR_WOL_STATUS     BIT(12)
  92 +#define LED2_FORCE_ON                                  (0x8 << 8)
  93 +#define LEDMASK                                                GENMASK(11,8)
  94 +
  95 +static struct phy_device *phydev;
  96 +
  97 +static void mvphy_reg_intn(u16 data)
  98 +{
  99 +       int rc = 0, saved_page;
 100 +
 101 +       saved_page = phy_select_page(phydev, MII_MARVELL_LED_PAGE);
 102 +       if (saved_page < 0)
 103 +               goto err;
 104 +
 105 +       /* Force manual LED2 control to let INTn work */
 106 +       __phy_modify(phydev, MII_PHY_LED_CTRL, LEDMASK, LED2_FORCE_ON);
 107 +
 108 +       /* Set the LED[2]/INTn pin to the required state */
 109 +       __phy_modify(phydev, MII_88E1318S_PHY_LED_TCR,
 110 +                    MII_88E1318S_PHY_LED_TCR_FORCE_INT,
 111 +                    MII_88E1318S_PHY_LED_TCR_INTn_ENABLE | data);
 112 +
 113 +       if (!data) {
 114 +               /* Clear interrupts to ensure INTn won't be holded in high state */
 115 +               __phy_write(phydev, MII_MARVELL_PHY_PAGE, MII_MARVELL_COPPER_PAGE);
 116 +               __phy_read(phydev, MII_M1011_IEVENT);
 117 +
 118 +               /* If WOL was enabled and a magic packet was received before powering
 119 +                * off, we won't be able to wake up by sending another magic packet.
 120 +                * Clear WOL status.
 121 +                */
 122 +               __phy_write(phydev, MII_MARVELL_PHY_PAGE, MII_MARVELL_WOL_PAGE);
 123 +               __phy_set_bits(phydev, MII_88E1318S_PHY_WOL_CTRL,
 124 +                              MII_88E1318S_PHY_WOL_CTRL_CLEAR_WOL_STATUS);
 125 +       }
 126 +err:
 127 +       rc = phy_restore_page(phydev, saved_page, rc);
 128 +       if (rc < 0)
 129 +               dev_err(&phydev->mdio.dev, "Write register failed, %d\n", rc);
 130 +}
 131 +
 132 +static int linkstation_reboot_notifier(struct notifier_block *nb,
 133 +                                      unsigned long action, void *unused)
 134 +{
 135 +       if (action == SYS_RESTART)
 136 +               mvphy_reg_intn(MII_88E1318S_PHY_LED_TCR_FORCE_INT);
 137 +
 138 +       return NOTIFY_DONE;
 139 +}
 140 +
 141 +static struct notifier_block linkstation_reboot_nb = {
 142 +       .notifier_call = linkstation_reboot_notifier,
 143 +};
 144 +
 145 +static void linkstation_poweroff(void)
 146 +{
 147 +       unregister_reboot_notifier(&linkstation_reboot_nb);
 148 +       mvphy_reg_intn(0);
 149 +
 150 +       kernel_restart("Power off");
 151 +}
 152 +
 153 +static const struct of_device_id ls_poweroff_of_match[] = {
 154 +       { .compatible = "buffalo,ls421d" },
 155 +       { .compatible = "buffalo,ls421de" },
 156 +       { },
 157 +};
 158 +
 159 +static int __init linkstation_poweroff_init(void)
 160 +{
 161 +       struct mii_bus *bus;
 162 +       struct device_node *dn;
 163 +
 164 +       dn = of_find_matching_node(NULL, ls_poweroff_of_match);
 165 +       if (!dn)
 166 +               return -ENODEV;
 167 +       of_node_put(dn);
 168 +
 169 +       dn = of_find_node_by_name(NULL, "mdio");
 170 +       if (!dn)
 171 +               return -ENODEV;
 172 +
 173 +       bus = of_mdio_find_bus(dn);
 174 +       of_node_put(dn);
 175 +       if (!bus)
 176 +               return -EPROBE_DEFER;
 177 +
 178 +       phydev = phy_find_first(bus);
 179 +       if (!phydev)
 180 +               return -EPROBE_DEFER;
 181 +
 182 +       register_reboot_notifier(&linkstation_reboot_nb);
 183 +       pm_power_off = linkstation_poweroff;
 184 +
 185 +       return 0;
 186 +}
 187 +
 188 +static void __exit linkstation_poweroff_exit(void)
 189 +{
 190 +       pm_power_off = NULL;
 191 +       unregister_reboot_notifier(&linkstation_reboot_nb);
 192 +}
 193 +
 194 +module_init(linkstation_poweroff_init);
 195 +module_exit(linkstation_poweroff_exit);
 196 +
 197 +MODULE_AUTHOR("Daniel González Cabanelas <dgcbueu@gmail.com>");
 198 +MODULE_DESCRIPTION("LinkStation power off driver");
 199 +MODULE_LICENSE("GPL v2");