net: cpsw: Add a minimal cpsw-common module for shared code

Looks like davinci_emac and cpsw can share some code although the
device registers have a different layout.

At least the code for getting the MAC address using syscon can
be shared by passing the register offset. Let's start with that
and set up a minimal shared cpsw-shared.c.

Cc: Brian Hutchinson <b.hutchman@gmail.com>
Cc: Felipe Balbi <balbi@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 53 insertions, 0 deletions

diff --git a/drivers/net/ethernet/ti/cpsw-common.c b/drivers/net/ethernet/ti/cpsw-common.c
new file mode 100644
index 000000000000..763ada18ad3d
--- /dev/null
+++ b/drivers/net/ethernet/ti/cpsw-common.c
@@ -0,0 +1,53 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
+
+#define AM33XX_CTRL_MAC_LO_REG(offset, id) ((offset) + 0x8 * (id))
+#define AM33XX_CTRL_MAC_HI_REG(offset, id) ((offset) + 0x8 * (id) + 0x4)
+
+int cpsw_am33xx_cm_get_macid(struct device *dev, u16 offset, 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(offset, slave),
+		    &macid_lo);
+	regmap_read(syscon, AM33XX_CTRL_MAC_HI_REG(offset, 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;
+}
+EXPORT_SYMBOL_GPL(cpsw_am33xx_cm_get_macid);
+
+MODULE_LICENSE("GPL");