[PATCH v3 4/7] net: phy: realtek: Add helpers for accessing RTL8211E extension pages

[Matthias Kaehlcke <mka@chromium.org>]

The RTL8211E has 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 rtl8211e_modify_ext_paged() in
rtl8211e_config_init() instead of doing things 'manually'.

rtl8211e_modify_ext_paged() is inspired by its counterpart
phy_modify_paged().

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
---
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 | 57 +++++++++++++++++++++++++++++----------
 1 file changed, 43 insertions(+), 14 deletions(-)

diff --git a/drivers/net/phy/realtek.c b/drivers/net/phy/realtek.c
index 827ea7ed080d..fa11ae5ebd91 100644
--- a/drivers/net/phy/realtek.c
+++ b/drivers/net/phy/realtek.c
@@ -27,6 +27,8 @@
 #define RTL821x_EXT_PAGE_SELECT			0x1e
 #define RTL821x_PAGE_SELECT			0x1f
 
+#define RTL8211E_EXT_PAGE			7
+
 /* RTL8211E page 5 */
 #define RTL8211E_EEE_LED_MODE1			0x05
 #define RTL8211E_EEE_LED_MODE2			0x06
@@ -58,6 +60,44 @@ static int rtl821x_write_page(struct phy_device *phydev, int page)
 	return __phy_write(phydev, RTL821x_PAGE_SELECT, page);
 }
 
+static int rtl8211e_select_ext_page(struct phy_device *phydev, int page)
+{
+	int ret, oldpage;
+
+	oldpage = phy_select_page(phydev, RTL8211E_EXT_PAGE);
+	if (oldpage < 0)
+		return oldpage;
+
+	ret = __phy_write(phydev, RTL821x_EXT_PAGE_SELECT, page);
+	if (ret)
+		return phy_restore_page(phydev, page, ret);
+
+	return 0;
+}
+
+static int rtl8211e_modify_ext_paged(struct phy_device *phydev, int page,
+				     u32 regnum, u16 mask, u16 set)
+{
+	int ret = 0;
+	int oldpage;
+	int new;
+
+	oldpage = rtl8211e_select_ext_page(phydev, page);
+	if (oldpage < 0)
+		goto out;
+
+	ret = __phy_read(phydev, regnum);
+	if (ret < 0)
+		goto out;
+
+	new = (ret & ~mask) | set;
+	if (new != ret)
+		ret = __phy_write(phydev, regnum, new);
+
+out:
+	return phy_restore_page(phydev, oldpage, ret);
+}
+
 static void rtl8211e_disable_eee_led_mode(struct phy_device *phydev)
 {
 	int oldpage;
@@ -210,7 +250,6 @@ static int rtl8211f_config_init(struct phy_device *phydev)
 static int rtl8211e_config_init(struct phy_device *phydev)
 {
 	struct device *dev = &phydev->mdio.dev;
-	int ret = 0, oldpage;
 	u16 val;
 
 	if (of_property_read_bool(dev->of_node, "realtek,eee-led-mode-disable"))
@@ -242,19 +281,9 @@ 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 rtl8211e_modify_ext_paged(phydev, 0xa4, 0x1c,
+					 RTL8211E_TX_DELAY | RTL8211E_RX_DELAY,
+					 val);
 }
 
 static int rtl8211b_suspend(struct phy_device *phydev)
-- 
2.22.0.410.gd8fdbe21b5-goog