drivers: net: xgene: Backward compatibility with older firmware

This patch adds support when used with older firmware (<= 1.13.28).

- Added xgene_ring_mgr_init() to check whether ring manager is initialized
- Calling xgene_ring_mgr_init() from xgene_port_ops.reset()
- To handle errors, changed the return type of xgene_port_ops.reset()

Signed-off-by: Iyappan Subramanian <isubramanian@apm.com>
Signed-off-by: Keyur Chudgar <kchudgar@apm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/apm/xgene/xgene_enet_hw.c

@@ -575,10 +575,24 @@ static void xgene_gmac_tx_disable(struct xgene_enet_pdata *pdata)
 	xgene_enet_wr_mcx_mac(pdata, MAC_CONFIG_1_ADDR, data & ~TX_EN);
 }
 
-static void xgene_enet_reset(struct xgene_enet_pdata *pdata)
+bool xgene_ring_mgr_init(struct xgene_enet_pdata *p)
+{
+	if (!ioread32(p->ring_csr_addr + CLKEN_ADDR))
+		return false;
+
+	if (ioread32(p->ring_csr_addr + SRST_ADDR))
+		return false;
+
+	return true;
+}
+
+static int xgene_enet_reset(struct xgene_enet_pdata *pdata)
 {
 	u32 val;
 
+	if (!xgene_ring_mgr_init(pdata))
+		return -ENODEV;
+
 	clk_prepare_enable(pdata->clk);
 	clk_disable_unprepare(pdata->clk);
 	clk_prepare_enable(pdata->clk);
@@ -590,6 +604,8 @@ static void xgene_enet_reset(struct xgene_enet_pdata *pdata)
 	val |= SCAN_AUTO_INCR;
 	MGMT_CLOCK_SEL_SET(&val, 1);
 	xgene_enet_wr_mcx_mac(pdata, MII_MGMT_CONFIG_ADDR, val);
+
+	return 0;
 }
 
 static void xgene_gport_shutdown(struct xgene_enet_pdata *pdata)

drivers/net/ethernet/apm/xgene/xgene_enet_hw.h

@@ -104,6 +104,9 @@ enum xgene_enet_rm {
 #define BLOCK_ETH_MAC_OFFSET		0x0000
 #define BLOCK_ETH_MAC_CSR_OFFSET	0x2800
 
+#define CLKEN_ADDR			0xc208
+#define SRST_ADDR			0xc200
+
 #define MAC_ADDR_REG_OFFSET		0x00
 #define MAC_COMMAND_REG_OFFSET		0x04
 #define MAC_WRITE_REG_OFFSET		0x08
@@ -318,6 +321,7 @@ void xgene_enet_parse_error(struct xgene_enet_desc_ring *ring,
 
 int xgene_enet_mdio_config(struct xgene_enet_pdata *pdata);
 void xgene_enet_mdio_remove(struct xgene_enet_pdata *pdata);
+bool xgene_ring_mgr_init(struct xgene_enet_pdata *p);
 
 extern struct xgene_mac_ops xgene_gmac_ops;
 extern struct xgene_port_ops xgene_gport_ops;

drivers/net/ethernet/apm/xgene/xgene_enet_main.c

@@ -852,7 +852,9 @@ static int xgene_enet_init_hw(struct xgene_enet_pdata *pdata)
 	u16 dst_ring_num;
 	int ret;
 
-	pdata->port_ops->reset(pdata);
+	ret = pdata->port_ops->reset(pdata);
+	if (ret)
+		return ret;
 
 	ret = xgene_enet_create_desc_rings(ndev);
 	if (ret) {
@@ -954,6 +956,7 @@ static int xgene_enet_probe(struct platform_device *pdev)
 
 	return ret;
 err:
+	unregister_netdev(ndev);
 	free_netdev(ndev);
 	return ret;
 }

drivers/net/ethernet/apm/xgene/xgene_enet_main.h

@@ -83,7 +83,7 @@ struct xgene_mac_ops {
 };
 
 struct xgene_port_ops {
-	void (*reset)(struct xgene_enet_pdata *pdata);
+	int (*reset)(struct xgene_enet_pdata *pdata);
 	void (*cle_bypass)(struct xgene_enet_pdata *pdata,
 			   u32 dst_ring_num, u16 bufpool_id);
 	void (*shutdown)(struct xgene_enet_pdata *pdata);

drivers/net/ethernet/apm/xgene/xgene_enet_sgmac.c

@@ -311,14 +311,19 @@ static void xgene_sgmac_tx_disable(struct xgene_enet_pdata *p)
 	xgene_sgmac_rxtx(p, TX_EN, false);
 }
 
-static void xgene_enet_reset(struct xgene_enet_pdata *p)
+static int xgene_enet_reset(struct xgene_enet_pdata *p)
 {
+	if (!xgene_ring_mgr_init(p))
+		return -ENODEV;
+
 	clk_prepare_enable(p->clk);
 	clk_disable_unprepare(p->clk);
 	clk_prepare_enable(p->clk);
 
 	xgene_enet_ecc_init(p);
 	xgene_enet_config_ring_if_assoc(p);
+
+	return 0;
 }
 
 static void xgene_enet_cle_bypass(struct xgene_enet_pdata *p,

drivers/net/ethernet/apm/xgene/xgene_enet_xgmac.c

@@ -252,14 +252,19 @@ static void xgene_xgmac_tx_disable(struct xgene_enet_pdata *pdata)
 	xgene_enet_wr_mac(pdata, AXGMAC_CONFIG_1, data & ~HSTTFEN);
 }
 
-static void xgene_enet_reset(struct xgene_enet_pdata *pdata)
+static int xgene_enet_reset(struct xgene_enet_pdata *pdata)
 {
+	if (!xgene_ring_mgr_init(pdata))
+		return -ENODEV;
+
 	clk_prepare_enable(pdata->clk);
 	clk_disable_unprepare(pdata->clk);
 	clk_prepare_enable(pdata->clk);
 
 	xgene_enet_ecc_init(pdata);
 	xgene_enet_config_ring_if_assoc(pdata);
+
+	return 0;
 }
 
 static void xgene_enet_xgcle_bypass(struct xgene_enet_pdata *pdata,