target/linux/generic/backport-4.19/706-v5.1-net-phy-add-register-modifying-helpers-returning-1-o.patch

   1 From c1e3f753f6b85d7636024159bb78f764e09492f1 Mon Sep 17 00:00:00 2001
   2 From: Heiner Kallweit <hkallweit1@gmail.com>
   3 Date: Sun, 10 Feb 2019 19:57:56 +0100
   4 Subject: [PATCH 604/660] net: phy: add register modifying helpers returning 1
   5  on change
   6
   7 When modifying registers there are scenarios where we need to know
   8 whether the register content actually changed. This patch adds
   9 new helpers to not break users of the current ones, phy_modify() etc.
  10
  11 Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
  12 Reviewed-by: Andrew Lunn <andrew@lunn.ch>
  13 Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
  14 Signed-off-by: David S. Miller <davem@davemloft.net>
  15 Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
  16 ---
  17  drivers/net/phy/phy-core.c | 127 ++++++++++++++++++++++++++++++++++---
  18  include/linux/phy.h        |  12 +++-
  19  2 files changed, 128 insertions(+), 11 deletions(-)
  20
  21 --- a/drivers/net/phy/phy-core.c
  22 +++ b/drivers/net/phy/phy-core.c
  23 @@ -364,7 +364,7 @@ int phy_write_mmd(struct phy_device *phy
  24  EXPORT_SYMBOL(phy_write_mmd);
  25
  26  /**
  27 - * __phy_modify() - Convenience function for modifying a PHY register
  28 + * __phy_modify_changed() - Convenience function for modifying a PHY register
  29   * @phydev: a pointer to a &struct phy_device
  30   * @regnum: register number
  31   * @mask: bit mask of bits to clear
  32 @@ -372,16 +372,69 @@ EXPORT_SYMBOL(phy_write_mmd);
  33   *
  34   * Unlocked helper function which allows a PHY register to be modified as
  35   * new register value = (old register value & ~mask) | set
  36 + *
  37 + * Returns negative errno, 0 if there was no change, and 1 in case of change
  38   */
  39 -int __phy_modify(struct phy_device *phydev, u32 regnum, u16 mask, u16 set)
  40 +int __phy_modify_changed(struct phy_device *phydev, u32 regnum, u16 mask,
  41 +                        u16 set)
  42  {
  43 -       int ret;
  44 +       int new, ret;
  45
  46         ret = __phy_read(phydev, regnum);
  47         if (ret < 0)
  48                 return ret;
  49
  50 -       ret = __phy_write(phydev, regnum, (ret & ~mask) | set);
  51 +       new = (ret & ~mask) | set;
  52 +       if (new == ret)
  53 +               return 0;
  54 +
  55 +       ret = __phy_write(phydev, regnum, new);
  56 +
  57 +       return ret < 0 ? ret : 1;
  58 +}
  59 +EXPORT_SYMBOL_GPL(__phy_modify_changed);
  60 +
  61 +/**
  62 + * phy_modify_changed - Function for modifying a PHY register
  63 + * @phydev: the phy_device struct
  64 + * @regnum: register number to modify
  65 + * @mask: bit mask of bits to clear
  66 + * @set: new value of bits set in mask to write to @regnum
  67 + *
  68 + * NOTE: MUST NOT be called from interrupt context,
  69 + * because the bus read/write functions may wait for an interrupt
  70 + * to conclude the operation.
  71 + *
  72 + * Returns negative errno, 0 if there was no change, and 1 in case of change
  73 + */
  74 +int phy_modify_changed(struct phy_device *phydev, u32 regnum, u16 mask, u16 set)
  75 +{
  76 +       int ret;
  77 +
  78 +       mutex_lock(&phydev->mdio.bus->mdio_lock);
  79 +       ret = __phy_modify_changed(phydev, regnum, mask, set);
  80 +       mutex_unlock(&phydev->mdio.bus->mdio_lock);
  81 +
  82 +       return ret;
  83 +}
  84 +EXPORT_SYMBOL_GPL(phy_modify_changed);
  85 +
  86 +/**
  87 + * __phy_modify - Convenience function for modifying a PHY register
  88 + * @phydev: the phy_device struct
  89 + * @regnum: register number to modify
  90 + * @mask: bit mask of bits to clear
  91 + * @set: new value of bits set in mask to write to @regnum
  92 + *
  93 + * NOTE: MUST NOT be called from interrupt context,
  94 + * because the bus read/write functions may wait for an interrupt
  95 + * to conclude the operation.
  96 + */
  97 +int __phy_modify(struct phy_device *phydev, u32 regnum, u16 mask, u16 set)
  98 +{
  99 +       int ret;
 100 +
 101 +       ret = __phy_modify_changed(phydev, regnum, mask, set);
 102
 103         return ret < 0 ? ret : 0;
 104  }
 105 @@ -411,7 +464,7 @@ int phy_modify(struct phy_device *phydev
 106  EXPORT_SYMBOL_GPL(phy_modify);
 107
 108  /**
 109 - * __phy_modify_mmd - Convenience function for modifying a register on MMD
 110 + * __phy_modify_mmd_changed - Function for modifying a register on MMD
 111   * @phydev: the phy_device struct
 112   * @devad: the MMD containing register to modify
 113   * @regnum: register number to modify
 114 @@ -420,17 +473,73 @@ EXPORT_SYMBOL_GPL(phy_modify);
 115   *
 116   * Unlocked helper function which allows a MMD register to be modified as
 117   * new register value = (old register value & ~mask) | set
 118 + *
 119 + * Returns negative errno, 0 if there was no change, and 1 in case of change
 120   */
 121 -int __phy_modify_mmd(struct phy_device *phydev, int devad, u32 regnum,
 122 -                    u16 mask, u16 set)
 123 +int __phy_modify_mmd_changed(struct phy_device *phydev, int devad, u32 regnum,
 124 +                            u16 mask, u16 set)
 125  {
 126 -       int ret;
 127 +       int new, ret;
 128
 129         ret = __phy_read_mmd(phydev, devad, regnum);
 130         if (ret < 0)
 131                 return ret;
 132
 133 -       ret = __phy_write_mmd(phydev, devad, regnum, (ret & ~mask) | set);
 134 +       new = (ret & ~mask) | set;
 135 +       if (new == ret)
 136 +               return 0;
 137 +
 138 +       ret = __phy_write_mmd(phydev, devad, regnum, new);
 139 +
 140 +       return ret < 0 ? ret : 1;
 141 +}
 142 +EXPORT_SYMBOL_GPL(__phy_modify_mmd_changed);
 143 +
 144 +/**
 145 + * phy_modify_mmd_changed - Function for modifying a register on MMD
 146 + * @phydev: the phy_device struct
 147 + * @devad: the MMD containing register to modify
 148 + * @regnum: register number to modify
 149 + * @mask: bit mask of bits to clear
 150 + * @set: new value of bits set in mask to write to @regnum
 151 + *
 152 + * NOTE: MUST NOT be called from interrupt context,
 153 + * because the bus read/write functions may wait for an interrupt
 154 + * to conclude the operation.
 155 + *
 156 + * Returns negative errno, 0 if there was no change, and 1 in case of change
 157 + */
 158 +int phy_modify_mmd_changed(struct phy_device *phydev, int devad, u32 regnum,
 159 +                          u16 mask, u16 set)
 160 +{
 161 +       int ret;
 162 +
 163 +       mutex_lock(&phydev->mdio.bus->mdio_lock);
 164 +       ret = __phy_modify_mmd_changed(phydev, devad, regnum, mask, set);
 165 +       mutex_unlock(&phydev->mdio.bus->mdio_lock);
 166 +
 167 +       return ret;
 168 +}
 169 +EXPORT_SYMBOL_GPL(phy_modify_mmd_changed);
 170 +
 171 +/**
 172 + * __phy_modify_mmd - Convenience function for modifying a register on MMD
 173 + * @phydev: the phy_device struct
 174 + * @devad: the MMD containing register to modify
 175 + * @regnum: register number to modify
 176 + * @mask: bit mask of bits to clear
 177 + * @set: new value of bits set in mask to write to @regnum
 178 + *
 179 + * NOTE: MUST NOT be called from interrupt context,
 180 + * because the bus read/write functions may wait for an interrupt
 181 + * to conclude the operation.
 182 + */
 183 +int __phy_modify_mmd(struct phy_device *phydev, int devad, u32 regnum,
 184 +                    u16 mask, u16 set)
 185 +{
 186 +       int ret;
 187 +
 188 +       ret = __phy_modify_mmd_changed(phydev, devad, regnum, mask, set);
 189
 190         return ret < 0 ? ret : 0;
 191  }
 192 --- a/include/linux/phy.h
 193 +++ b/include/linux/phy.h
 194 @@ -797,13 +797,21 @@ int phy_write_mmd(struct phy_device *phy
 195   */
 196  int __phy_write_mmd(struct phy_device *phydev, int devad, u32 regnum, u16 val);
 197
 198 +int __phy_modify_changed(struct phy_device *phydev, u32 regnum, u16 mask,
 199 +                        u16 set);
 200 +int phy_modify_changed(struct phy_device *phydev, u32 regnum, u16 mask,
 201 +                      u16 set);
 202  int __phy_modify(struct phy_device *phydev, u32 regnum, u16 mask, u16 set);
 203  int phy_modify(struct phy_device *phydev, u32 regnum, u16 mask, u16 set);
 204
 205 +int __phy_modify_mmd_changed(struct phy_device *phydev, int devad, u32 regnum,
 206 +                            u16 mask, u16 set);
 207 +int phy_modify_mmd_changed(struct phy_device *phydev, int devad, u32 regnum,
 208 +                          u16 mask, u16 set);
 209  int __phy_modify_mmd(struct phy_device *phydev, int devad, u32 regnum,
 210 -               u16 mask, u16 set);
 211 +                    u16 mask, u16 set);
 212  int phy_modify_mmd(struct phy_device *phydev, int devad, u32 regnum,
 213 -               u16 mask, u16 set);
 214 +                  u16 mask, u16 set);
 215
 216  /**
 217   * __phy_set_bits - Convenience function for setting bits in a PHY register