[PATCH v5 3/4] net: phy: realtek: Add helpers for accessing RTL8211x extension pages

[Matthias Kaehlcke <mka@chromium.org>]

Some RTL8211x PHYs have extension pages, which can be accessed
after selecting a page through a custom method. Add a function to
modify bits in a register of an extension page and a helper for
selecting an ext page. Use rtl8211x_modify_ext_paged() in
rtl8211e_config_init() instead of doing things 'manually'.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
---
Changes in v5:
- renamed 'rtl8211e_<action>_ext_page' to 'rtl8211x_<action>_ext_page'
- updated commit message

Changes in v4:
- don't add constant RTL8211E_EXT_PAGE, it's only used once,
  use a literal instead
- pass 'oldpage' to phy_restore_page() in rtl8211e_select_ext_page(),
  not 'page'
- return 'oldpage' in rtl8211e_select_ext_page()
- use __phy_modify() in rtl8211e_modify_ext_paged() instead of
  reimplementing __phy_modify_changed()
- in rtl8211e_modify_ext_paged() return directly when
  rtl8211e_select_ext_page() fails

Changes in v3:
- use the new function in rtl8211e_config_init() instead of
  doing things 'manually'
- use existing RTL8211E_EXT_PAGE instead of adding a new define
- updated commit message

Changes in v2:
- use phy_select_page() and phy_restore_page(), get rid of
  rtl8211e_restore_page()
- s/rtl821e_select_ext_page/rtl8211e_select_ext_page/
- updated commit message
---
 drivers/net/phy/realtek.c | 47 +++++++++++++++++++++++++++------------
 1 file changed, 33 insertions(+), 14 deletions(-)

diff --git a/drivers/net/phy/realtek.c b/drivers/net/phy/realtek.c
index a669945eb829..a5b3708dc4d8 100644
--- a/drivers/net/phy/realtek.c
+++ b/drivers/net/phy/realtek.c
@@ -53,6 +53,36 @@ static int rtl821x_write_page(struct phy_device *phydev, int page)
 	return __phy_write(phydev, RTL821x_PAGE_SELECT, page);
 }
 
+static int rtl8211x_select_ext_page(struct phy_device *phydev, int page)
+{
+	int ret, oldpage;
+
+	oldpage = phy_select_page(phydev, 7);
+	if (oldpage < 0)
+		return oldpage;
+
+	ret = __phy_write(phydev, RTL821x_EXT_PAGE_SELECT, page);
+	if (ret)
+		return phy_restore_page(phydev, oldpage, ret);
+
+	return oldpage;
+}
+
+static int rtl8211x_modify_ext_paged(struct phy_device *phydev, int page,
+				     u32 regnum, u16 mask, u16 set)
+{
+	int ret = 0;
+	int oldpage;
+
+	oldpage = rtl8211x_select_ext_page(phydev, page);
+	if (oldpage < 0)
+		return oldpage;
+
+	ret = __phy_modify(phydev, regnum, mask, set);
+
+	return phy_restore_page(phydev, oldpage, ret);
+}
+
 static int rtl8201_ack_interrupt(struct phy_device *phydev)
 {
 	int err;
@@ -184,7 +214,6 @@ static int rtl8211f_config_init(struct phy_device *phydev)
 
 static int rtl8211e_config_init(struct phy_device *phydev)
 {
-	int ret = 0, oldpage;
 	u16 val;
 
 	/* enable TX/RX delay for rgmii-* modes, and disable them for rgmii. */
@@ -213,19 +242,9 @@ static int rtl8211e_config_init(struct phy_device *phydev)
 	 * 2 = RX Delay, 1 = TX Delay, 0 = SELRGV (see original PHY datasheet
 	 * for details).
 	 */
-	oldpage = phy_select_page(phydev, 0x7);
-	if (oldpage < 0)
-		goto err_restore_page;
-
-	ret = __phy_write(phydev, RTL821x_EXT_PAGE_SELECT, 0xa4);
-	if (ret)
-		goto err_restore_page;
-
-	ret = __phy_modify(phydev, 0x1c, RTL8211E_TX_DELAY | RTL8211E_RX_DELAY,
-			   val);
-
-err_restore_page:
-	return phy_restore_page(phydev, oldpage, ret);
+	return rtl8211x_modify_ext_paged(phydev, 0xa4, 0x1c,
+					 RTL8211E_TX_DELAY | RTL8211E_RX_DELAY,
+					 val);
 }
 
 static int rtl8211b_suspend(struct phy_device *phydev)
-- 
2.22.0.770.g0f2c4a37fd-goog