net: cpsw: Add am33xx MACID readout

This patch adds a function to get the MACIDs from the am33xx SoC
control module registers which hold unique vendor MACIDs. This is only
used if of_get_mac_address() fails to get a valid mac address.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Reviewed-by: Wolfram Sang <wsa@the-dreams.de>
Tested-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 47 insertions, 1 deletions

diff --git a/Documentation/devicetree/bindings/net/cpsw.txt b/Documentation/devicetree/bindings/net/cpsw.txt
index 107caf174a0e..33fe8462edf4 100644
--- a/Documentation/devicetree/bindings/net/cpsw.txt
+++ b/Documentation/devicetree/bindings/net/cpsw.txt
@@ -24,6 +24,8 @@ Optional properties:
 - ti,hwmods             : Must be "cpgmac0"
 - no_bd_ram             : Must be 0 or 1
 - dual_emac             : Specifies Switch to act as Dual EMAC
+- syscon                : Phandle to the system control device node, which is
+                          the control module device of the am33x
 
 Slave Properties:
 Required properties:
@@ -57,6 +59,7 @@ Examples:
                 active_slave = <0>;
                 cpts_clock_mult = <0x80000000>;
                 cpts_clock_shift = <29>;
+                syscon = <&cm>;
                 cpsw_emac0: slave@0 {
                         phy_id = <&davinci_mdio>, <0>;
                         phy-mode = "rgmii-txid";
@@ -85,6 +88,7 @@ Examples:
                 active_slave = <0>;
                 cpts_clock_mult = <0x80000000>;
                 cpts_clock_shift = <29>;
+                syscon = <&cm>;
                 cpsw_emac0: slave@0 {
                         phy_id = <&davinci_mdio>, <0>;
                         phy-mode = "rgmii-txid";
diff --git a/drivers/net/ethernet/ti/Kconfig b/drivers/net/ethernet/ti/Kconfig
index 1769700a6070..5d8cb7956113 100644
--- a/drivers/net/ethernet/ti/Kconfig
+++ b/drivers/net/ethernet/ti/Kconfig
@@ -62,6 +62,8 @@ config TI_CPSW
         select TI_DAVINCI_CPDMA
         select TI_DAVINCI_MDIO
         select TI_CPSW_PHY_SEL
+        select MFD_SYSCON
+        select REGMAP
         ---help---
           This driver supports TI's CPSW Ethernet Switch.
 
diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c
index d2988aeb6682..ab167dc49ce4 100644
--- a/drivers/net/ethernet/ti/cpsw.c
+++ b/drivers/net/ethernet/ti/cpsw.c
@@ -33,6 +33,8 @@
 #include <linux/of_net.h>
 #include <linux/of_device.h>
 #include <linux/if_vlan.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
 
 #include <linux/pinctrl/consumer.h>
 
@@ -1876,6 +1878,36 @@ static void cpsw_slave_init(struct cpsw_slave *slave, struct cpsw_priv *priv,
         slave->port_vlan = data->dual_emac_res_vlan;
 }
 
+#define AM33XX_CTRL_MAC_LO_REG(id) (0x630 + 0x8 * id)
+#define AM33XX_CTRL_MAC_HI_REG(id) (0x630 + 0x8 * id + 0x4)
+
+static int cpsw_am33xx_cm_get_macid(struct device *dev, int slave,
+                u8 *mac_addr)
+{
+        u32 macid_lo;
+        u32 macid_hi;
+        struct regmap *syscon;
+
+        syscon = syscon_regmap_lookup_by_phandle(dev->of_node, "syscon");
+        if (IS_ERR(syscon)) {
+                if (PTR_ERR(syscon) == -ENODEV)
+                        return 0;
+                return PTR_ERR(syscon);
+        }
+
+        regmap_read(syscon, AM33XX_CTRL_MAC_LO_REG(slave), &macid_lo);
+        regmap_read(syscon, AM33XX_CTRL_MAC_HI_REG(slave), &macid_hi);
+
+        mac_addr[5] = (macid_lo >> 8) & 0xff;
+        mac_addr[4] = macid_lo & 0xff;
+        mac_addr[3] = (macid_hi >> 24) & 0xff;
+        mac_addr[2] = (macid_hi >> 16) & 0xff;
+        mac_addr[1] = (macid_hi >> 8) & 0xff;
+        mac_addr[0] = macid_hi & 0xff;
+
+        return 0;
+}
+
 static int cpsw_probe_dt(struct cpsw_platform_data *data,
                          struct platform_device *pdev)
 {
@@ -1988,8 +2020,16 @@ static int cpsw_probe_dt(struct cpsw_platform_data *data,
                          PHY_ID_FMT, mdio->name, phyid);
 
                 mac_addr = of_get_mac_address(slave_node);
-                if (mac_addr)
+                if (mac_addr) {
                         memcpy(slave_data->mac_addr, mac_addr, ETH_ALEN);
+                } else {
+                        if (of_machine_is_compatible("ti,am33xx")) {
+                                ret = cpsw_am33xx_cm_get_macid(&pdev->dev, i,
+                                                        slave_data->mac_addr);
+                                if (ret)
+                                        return ret;
+                        }
+                }
 
                 slave_data->phy_if = of_get_phy_mode(slave_node);
                 if (slave_data->phy_if < 0) {