r8169: factor out firmware handling

Let's factor out firmware handling into a separate source code file.
This simplifies reading the code and makes clearer what the interface
between driver and firmware handling is.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/realtek/r8169_firmware.c b/drivers/net/ethernet/realtek/r8169_firmware.c
new file mode 100644
index 0000000..8f54a2c
--- /dev/null
+++ b/drivers/net/ethernet/realtek/r8169_firmware.c
@@ -0,0 +1,231 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* r8169_firmware.c: RealTek 8169/8168/8101 ethernet driver.
+ *
+ * Copyright (c) 2002 ShuChen <shuchen@realtek.com.tw>
+ * Copyright (c) 2003 - 2007 Francois Romieu <romieu@fr.zoreil.com>
+ * Copyright (c) a lot of people too. Please respect their work.
+ *
+ * See MAINTAINERS file for support contact information.
+ */
+
+#include <linux/delay.h>
+#include <linux/firmware.h>
+
+#include "r8169_firmware.h"
+
+enum rtl_fw_opcode {
+	PHY_READ		= 0x0,
+	PHY_DATA_OR		= 0x1,
+	PHY_DATA_AND		= 0x2,
+	PHY_BJMPN		= 0x3,
+	PHY_MDIO_CHG		= 0x4,
+	PHY_CLEAR_READCOUNT	= 0x7,
+	PHY_WRITE		= 0x8,
+	PHY_READCOUNT_EQ_SKIP	= 0x9,
+	PHY_COMP_EQ_SKIPN	= 0xa,
+	PHY_COMP_NEQ_SKIPN	= 0xb,
+	PHY_WRITE_PREVIOUS	= 0xc,
+	PHY_SKIPN		= 0xd,
+	PHY_DELAY_MS		= 0xe,
+};
+
+struct fw_info {
+	u32	magic;
+	char	version[RTL_VER_SIZE];
+	__le32	fw_start;
+	__le32	fw_len;
+	u8	chksum;
+} __packed;
+
+#define FW_OPCODE_SIZE	sizeof(typeof(*((struct rtl_fw_phy_action *)0)->code))
+
+static bool rtl_fw_format_ok(struct rtl_fw *rtl_fw)
+{
+	const struct firmware *fw = rtl_fw->fw;
+	struct fw_info *fw_info = (struct fw_info *)fw->data;
+	struct rtl_fw_phy_action *pa = &rtl_fw->phy_action;
+
+	if (fw->size < FW_OPCODE_SIZE)
+		return false;
+
+	if (!fw_info->magic) {
+		size_t i, size, start;
+		u8 checksum = 0;
+
+		if (fw->size < sizeof(*fw_info))
+			return false;
+
+		for (i = 0; i < fw->size; i++)
+			checksum += fw->data[i];
+		if (checksum != 0)
+			return false;
+
+		start = le32_to_cpu(fw_info->fw_start);
+		if (start > fw->size)
+			return false;
+
+		size = le32_to_cpu(fw_info->fw_len);
+		if (size > (fw->size - start) / FW_OPCODE_SIZE)
+			return false;
+
+		strscpy(rtl_fw->version, fw_info->version, RTL_VER_SIZE);
+
+		pa->code = (__le32 *)(fw->data + start);
+		pa->size = size;
+	} else {
+		if (fw->size % FW_OPCODE_SIZE)
+			return false;
+
+		strscpy(rtl_fw->version, rtl_fw->fw_name, RTL_VER_SIZE);
+
+		pa->code = (__le32 *)fw->data;
+		pa->size = fw->size / FW_OPCODE_SIZE;
+	}
+
+	return true;
+}
+
+static bool rtl_fw_data_ok(struct rtl_fw *rtl_fw)
+{
+	struct rtl_fw_phy_action *pa = &rtl_fw->phy_action;
+	size_t index;
+
+	for (index = 0; index < pa->size; index++) {
+		u32 action = le32_to_cpu(pa->code[index]);
+		u32 regno = (action & 0x0fff0000) >> 16;
+
+		switch (action >> 28) {
+		case PHY_READ:
+		case PHY_DATA_OR:
+		case PHY_DATA_AND:
+		case PHY_MDIO_CHG:
+		case PHY_CLEAR_READCOUNT:
+		case PHY_WRITE:
+		case PHY_WRITE_PREVIOUS:
+		case PHY_DELAY_MS:
+			break;
+
+		case PHY_BJMPN:
+			if (regno > index)
+				goto out;
+			break;
+		case PHY_READCOUNT_EQ_SKIP:
+			if (index + 2 >= pa->size)
+				goto out;
+			break;
+		case PHY_COMP_EQ_SKIPN:
+		case PHY_COMP_NEQ_SKIPN:
+		case PHY_SKIPN:
+			if (index + 1 + regno >= pa->size)
+				goto out;
+			break;
+
+		default:
+			dev_err(rtl_fw->dev, "Invalid action 0x%08x\n", action);
+			return false;
+		}
+	}
+
+	return true;
+out:
+	dev_err(rtl_fw->dev, "Out of range of firmware\n");
+	return false;
+}
+
+void rtl_fw_write_firmware(struct rtl8169_private *tp, struct rtl_fw *rtl_fw)
+{
+	struct rtl_fw_phy_action *pa = &rtl_fw->phy_action;
+	rtl_fw_write_t fw_write = rtl_fw->phy_write;
+	rtl_fw_read_t fw_read = rtl_fw->phy_read;
+	int predata = 0, count = 0;
+	size_t index;
+
+	for (index = 0; index < pa->size; index++) {
+		u32 action = le32_to_cpu(pa->code[index]);
+		u32 data = action & 0x0000ffff;
+		u32 regno = (action & 0x0fff0000) >> 16;
+		enum rtl_fw_opcode opcode = action >> 28;
+
+		if (!action)
+			break;
+
+		switch (opcode) {
+		case PHY_READ:
+			predata = fw_read(tp, regno);
+			count++;
+			break;
+		case PHY_DATA_OR:
+			predata |= data;
+			break;
+		case PHY_DATA_AND:
+			predata &= data;
+			break;
+		case PHY_BJMPN:
+			index -= (regno + 1);
+			break;
+		case PHY_MDIO_CHG:
+			if (data == 0) {
+				fw_write = rtl_fw->phy_write;
+				fw_read = rtl_fw->phy_read;
+			} else if (data == 1) {
+				fw_write = rtl_fw->mac_mcu_write;
+				fw_read = rtl_fw->mac_mcu_read;
+			}
+
+			break;
+		case PHY_CLEAR_READCOUNT:
+			count = 0;
+			break;
+		case PHY_WRITE:
+			fw_write(tp, regno, data);
+			break;
+		case PHY_READCOUNT_EQ_SKIP:
+			if (count == data)
+				index++;
+			break;
+		case PHY_COMP_EQ_SKIPN:
+			if (predata == data)
+				index += regno;
+			break;
+		case PHY_COMP_NEQ_SKIPN:
+			if (predata != data)
+				index += regno;
+			break;
+		case PHY_WRITE_PREVIOUS:
+			fw_write(tp, regno, predata);
+			break;
+		case PHY_SKIPN:
+			index += regno;
+			break;
+		case PHY_DELAY_MS:
+			mdelay(data);
+			break;
+		}
+	}
+}
+
+void rtl_fw_release_firmware(struct rtl_fw *rtl_fw)
+{
+	release_firmware(rtl_fw->fw);
+}
+
+int rtl_fw_request_firmware(struct rtl_fw *rtl_fw)
+{
+	int rc;
+
+	rc = request_firmware(&rtl_fw->fw, rtl_fw->fw_name, rtl_fw->dev);
+	if (rc < 0)
+		goto out;
+
+	if (!rtl_fw_format_ok(rtl_fw) || !rtl_fw_data_ok(rtl_fw)) {
+		release_firmware(rtl_fw->fw);
+		rc = -EINVAL;
+		goto out;
+	}
+
+	return 0;
+out:
+	dev_err(rtl_fw->dev, "Unable to load firmware %s (%d)\n",
+		rtl_fw->fw_name, rc);
+	return rc;
+}