Merge branch 'mediatek-reset-flow'

Sean Wang says:

====================
mediatek: add enhancement into the existing reset flow

Current driver only resets DMA used by descriptor rings which
can't guarantee it can recover all various kinds of fatal
errors, so the patch
1) tries to reset the underlying hardware resource from scratch on
Mediatek SoC required for ethernet running.
2) refactors code in order to the reusability of existing code.
3) considers handling for race condition between the reset flow and
callbacks registered into core driver called about hardware accessing.
4) introduces power domain usage to hardware setup which leads to have
cleanly and completely restore to the state as the initial.

Changes since v1:
- fix the build error with module built causing undefined symbol for
  pinctrl_bind_pins, so using pinctrl_select_state instead accomplishes
  the pin mux setup during the reset process.
====================
Reviewed-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mediatek/mtk_eth_soc.h

@@ -266,6 +266,11 @@
 #define SYSCFG0_GE_MASK		0x3
 #define SYSCFG0_GE_MODE(x, y)	(x << (12 + (y * 2)))
 
+/*ethernet reset control register*/
+#define ETHSYS_RSTCTRL		0x34
+#define RSTCTRL_FE		BIT(6)
+#define RSTCTRL_PPE		BIT(31)
+
 struct mtk_rx_dma {
 	unsigned int rxd1;
 	unsigned int rxd2;
@@ -330,6 +335,11 @@ enum mtk_clks_map {
 	MTK_CLK_MAX
 };
 
+enum mtk_dev_state {
+	MTK_HW_INIT,
+	MTK_RESETTING
+};
+
 /* struct mtk_tx_buf -	This struct holds the pointers to the memory pointed at
  *			by the TX descriptor	s
  * @skb:		The SKB pointer of the packet being sent
@@ -413,12 +423,12 @@ struct mtk_rx_ring {
  * @clks:		clock array for all clocks required
  * @mii_bus:		If there is a bus we need to create an instance for it
  * @pending_work:	The workqueue used to reset the dma ring
+ * @state               Initialization and runtime state of the device.
  */
 
 struct mtk_eth {
 	struct device			*dev;
 	void __iomem			*base;
-	struct reset_control		*rstc;
 	spinlock_t			page_lock;
 	spinlock_t			irq_lock;
 	struct net_device		dummy_dev;
@@ -441,11 +451,13 @@ struct mtk_eth {
 
 	struct mii_bus			*mii_bus;
 	struct work_struct		pending_work;
+	unsigned long			state;
 };
 
 /* struct mtk_mac -	the structure that holds the info about the MACs of the
  *			SoC
  * @id:			The number of the MAC
+ * @ge_mode:            Interface mode kept for setup restoring
  * @of_node:		Our devicetree node
  * @hw:			Backpointer to our main datastruture
  * @hw_stats:		Packet statistics counter
@@ -453,6 +465,7 @@ struct mtk_eth {
  */
 struct mtk_mac {
 	int				id;
+	int				ge_mode;
 	struct device_node		*of_node;
 	struct mtk_eth			*hw;
 	struct mtk_hw_stats		*hw_stats;