[v10,4/5] usb: renesas-xhci: Add ROM loader for uPD720201

diff --git a/drivers/usb/host/xhci-pci-renesas.c b/drivers/usb/host/xhci-pci-renesas.c
index 402e86912c9f..6bb537999754 100644
--- a/drivers/usb/host/xhci-pci-renesas.c
+++ b/drivers/usb/host/xhci-pci-renesas.c
@@ -50,6 +50,22 @@ 
 #define RENESAS_RETRY	10000
 #define RENESAS_DELAY	10
 
+#define ROM_VALID_01 0x2013
+#define ROM_VALID_02 0x2026
+
+static int renesas_verify_fw_version(struct pci_dev *pdev, u32 version)
+{
+	switch (version) {
+	case ROM_VALID_01:
+	case ROM_VALID_02:
+		return 0;
+	default:
+		dev_err(&pdev->dev, "FW has invalid version :%d\n", version);
+		return 1;
+	}
+	return -EINVAL;
+}
+
 static int renesas_fw_download_image(struct pci_dev *dev,
 				     const u32 *fw,
 				     size_t step)
@@ -144,10 +160,84 @@  static int renesas_fw_verify(const void *fw_data,
 	return 0;
 }
 
-static int renesas_fw_check_running(struct pci_dev *pdev)
+static bool renesas_check_rom(struct pci_dev *pdev)
 {
+	u16 rom_status;
+	int retval;
+
+	/* Check if external ROM exists */
+	retval = pci_read_config_word(pdev, RENESAS_ROM_STATUS, &rom_status);
+	if (retval)
+		return false;
+
+	rom_status &= RENESAS_ROM_STATUS_ROM_EXISTS;
+	if (rom_status) {
+		dev_dbg(&pdev->dev, "External ROM exists\n");
+		return true; /* External ROM exists */
+	}
+
+	return false;
+}
+
+static int renesas_check_rom_state(struct pci_dev *pdev)
+{
+	u16 rom_state;
+	u32 version;
 	int err;
+
+	/* check FW version */
+	err = pci_read_config_dword(pdev, RENESAS_FW_VERSION, &version);
+	if (err)
+		return pcibios_err_to_errno(err);
+
+	version &= RENESAS_FW_VERSION_FIELD;
+	version = version >> RENESAS_FW_VERSION_OFFSET;
+
+	err = renesas_verify_fw_version(pdev, version);
+	if (err)
+		return err;
+
+	/*
+	 * Test if ROM is present and loaded, if so we can skip everything
+	 */
+	err = pci_read_config_word(pdev, RENESAS_ROM_STATUS, &rom_state);
+	if (err)
+		return pcibios_err_to_errno(err);
+
+	if (rom_state & BIT(15)) {
+		/* ROM exists */
+		dev_dbg(&pdev->dev, "ROM exists\n");
+
+		/* Check the "Result Code" Bits (6:4) and act accordingly */
+		switch (rom_state & RENESAS_ROM_STATUS_RESULT) {
+		case RENESAS_ROM_STATUS_SUCCESS:
+			return 0;
+
+		case RENESAS_ROM_STATUS_NO_RESULT: /* No result yet */
+			return 0;
+
+		case RENESAS_ROM_STATUS_ERROR: /* Error State */
+		default: /* All other states are marked as "Reserved states" */
+			dev_err(&pdev->dev, "Invalid ROM..");
+			break;
+		}
+	}
+
+	return -EIO;
+}
+
+static int renesas_fw_check_running(struct pci_dev *pdev)
+{
 	u8 fw_state;
+	int err;
+
+	/* Check if device has ROM and loaded, if so skip everything */
+	err = renesas_check_rom(pdev);
+	if (err) { /* we have rom */
+		err = renesas_check_rom_state(pdev);
+		if (!err)
+			return err;
+	}
 
 	/*
 	 * Test if the device is actually needing the firmware. As most
@@ -303,11 +393,261 @@  static int renesas_fw_download(struct pci_dev *pdev,
 	return 0;
 }
 
+static void renesas_rom_erase(struct pci_dev *pdev)
+{
+	int retval, i;
+	u8 status;
+
+	dev_dbg(&pdev->dev, "Performing ROM Erase...\n");
+	retval = pci_write_config_dword(pdev, RENESAS_DATA0,
+					RENESAS_ROM_ERASE_MAGIC);
+	if (retval) {
+		dev_err(&pdev->dev, "ROM erase, magic word write failed: %d\n",
+			pcibios_err_to_errno(retval));
+		return;
+	}
+
+	retval = pci_read_config_byte(pdev, RENESAS_ROM_STATUS, &status);
+	if (retval) {
+		dev_err(&pdev->dev, "ROM status read failed: %d\n",
+			pcibios_err_to_errno(retval));
+		return;
+	}
+	status |= RENESAS_ROM_STATUS_ERASE;
+	retval = pci_write_config_byte(pdev, RENESAS_ROM_STATUS, status);
+	if (retval) {
+		dev_err(&pdev->dev, "ROM erase set word write failed\n");
+		return;
+	}
+
+	/* sleep a bit while ROM is erased */
+	msleep(20);
+
+	for (i = 0; i < RENESAS_RETRY; i++) {
+		retval = pci_read_config_byte(pdev, RENESAS_ROM_STATUS,
+					      &status);
+		status &= RENESAS_ROM_STATUS_ERASE;
+		if (!status)
+			break;
+
+		mdelay(RENESAS_DELAY);
+	}
+
+	if (i == RENESAS_RETRY)
+		dev_dbg(&pdev->dev, "Chip erase timedout: %x\n", status);
+
+	dev_dbg(&pdev->dev, "ROM Erase... Done success\n");
+}
+
+static bool renesas_download_rom(struct pci_dev *pdev,
+				 const u32 *fw, size_t step)
+{
+	bool data0_or_data1;
+	u8 fw_status;
+	size_t i;
+	int err;
+
+	/*
+	 * The hardware does alternate between two 32-bit pages.
+	 * (This is because each row of the firmware is 8 bytes).
+	 *
+	 * for even steps we use DATA0, for odd steps DATA1.
+	 */
+	data0_or_data1 = (step & 1) == 1;
+
+	/* Read "Set DATAX" and confirm it is cleared. */
+	for (i = 0; i < RENESAS_RETRY; i++) {
+		err = pci_read_config_byte(pdev, RENESAS_ROM_STATUS_MSB,
+					   &fw_status);
+		if (err) {
+			dev_err(&pdev->dev, "Read ROM Status failed: %d\n",
+				pcibios_err_to_errno(err));
+			return false;
+		}
+		if (!(fw_status & BIT(data0_or_data1)))
+			break;
+
+		udelay(RENESAS_DELAY);
+	}
+	if (i == RENESAS_RETRY) {
+		dev_err(&pdev->dev, "Timeout for Set DATAX step: %zd\n", step);
+		return false;
+	}
+
+	/*
+	 * Write FW data to "DATAX".
+	 * "LSB is left" => force little endian
+	 */
+	err = pci_write_config_dword(pdev, data0_or_data1 ?
+				     RENESAS_DATA1 : RENESAS_DATA0,
+				     (__force u32)cpu_to_le32(fw[step]));
+	if (err) {
+		dev_err(&pdev->dev, "Write to DATAX failed: %d\n",
+			pcibios_err_to_errno(err));
+		return false;
+	}
+
+	udelay(100);
+
+	/* Set "Set DATAX". */
+	err = pci_write_config_byte(pdev, RENESAS_ROM_STATUS_MSB,
+				    BIT(data0_or_data1));
+	if (err) {
+		dev_err(&pdev->dev, "Write config for DATAX failed: %d\n",
+			pcibios_err_to_errno(err));
+		return false;
+	}
+
+	return true;
+}
+
+static bool renesas_setup_rom(struct pci_dev *pdev, const struct firmware *fw)
+{
+	const u32 *fw_data = (const u32 *)fw->data;
+	int err, i;
+	u8 status;
+
+	/* 2. Write magic word to Data0 */
+	err = pci_write_config_dword(pdev, RENESAS_DATA0,
+				     RENESAS_ROM_WRITE_MAGIC);
+	if (err)
+		return false;
+
+	/* 3. Set External ROM access */
+	err = pci_write_config_byte(pdev, RENESAS_ROM_STATUS,
+				    RENESAS_ROM_STATUS_ACCESS);
+	if (err)
+		goto remove_bypass;
+
+	/* 4. Check the result */
+	err = pci_read_config_byte(pdev, RENESAS_ROM_STATUS, &status);
+	if (err)
+		goto remove_bypass;
+	status &= GENMASK(6, 4);
+	if (status) {
+		dev_err(&pdev->dev,
+			"setting external rom failed: %x\n", status);
+		goto remove_bypass;
+	}
+
+	/* 5 to 16 Write FW to DATA0/1 while checking SetData0/1 */
+	for (i = 0; i < fw->size / 4; i++) {
+		err = renesas_download_rom(pdev, fw_data, i);
+		if (!err) {
+			dev_err(&pdev->dev,
+				"ROM Download Step %d failed at position %d bytes\n",
+				 i, i * 4);
+			goto remove_bypass;
+		}
+	}
+
+	/*
+	 * wait till DATA0/1 is cleared
+	 */
+	for (i = 0; i < RENESAS_RETRY; i++) {
+		err = pci_read_config_byte(pdev, RENESAS_ROM_STATUS_MSB,
+					   &status);
+		if (err)
+			goto remove_bypass;
+		if (!(status & (BIT(0) | BIT(1))))
+			break;
+
+		udelay(RENESAS_DELAY);
+	}
+	if (i == RENESAS_RETRY) {
+		dev_err(&pdev->dev, "Final Firmware ROM Download step timed out\n");
+		goto remove_bypass;
+	}
+
+	/* 17. Remove bypass */
+	err = pci_write_config_byte(pdev, RENESAS_ROM_STATUS, 0);
+	if (err)
+		return false;
+
+	udelay(10);
+
+	/* 18. check result */
+	for (i = 0; i < RENESAS_RETRY; i++) {
+		err = pci_read_config_byte(pdev, RENESAS_ROM_STATUS, &status);
+		if (err) {
+			dev_err(&pdev->dev, "Read ROM status failed:%d\n",
+				pcibios_err_to_errno(err));
+			return false;
+		}
+		status &= RENESAS_ROM_STATUS_RESULT;
+		if (status ==  RENESAS_ROM_STATUS_SUCCESS) {
+			dev_dbg(&pdev->dev, "Download ROM success\n");
+			break;
+		}
+		udelay(RENESAS_DELAY);
+	}
+	if (i == RENESAS_RETRY) { /* Timed out */
+		dev_err(&pdev->dev,
+			"Download to external ROM TO: %x\n", status);
+		return false;
+	}
+
+	dev_dbg(&pdev->dev, "Download to external ROM succeeded\n");
+
+	/* Last step set Reload */
+	err = pci_write_config_byte(pdev, RENESAS_ROM_STATUS,
+				    RENESAS_ROM_STATUS_RELOAD);
+	if (err) {
+		dev_err(&pdev->dev, "Set ROM execute failed: %d\n",
+			pcibios_err_to_errno(err));
+		return false;
+	}
+
+	/*
+	 * wait till Reload is cleared
+	 */
+	for (i = 0; i < RENESAS_RETRY; i++) {
+		err = pci_read_config_byte(pdev, RENESAS_ROM_STATUS, &status);
+		if (err)
+			return false;
+		if (!(status & RENESAS_ROM_STATUS_RELOAD))
+			break;
+
+		udelay(RENESAS_DELAY);
+	}
+	if (i == RENESAS_RETRY) {
+		dev_err(&pdev->dev, "ROM Exec timed out: %x\n", status);
+		return false;
+	}
+
+	return true;
+
+remove_bypass:
+	pci_write_config_byte(pdev, RENESAS_ROM_STATUS, 0);
+	return false;
+}
+
 static int renesas_load_fw(struct pci_dev *pdev, const struct firmware *fw)
 {
 	int err = 0;
+	bool rom;
+
+	/* Check if the device has external ROM */
+	rom = renesas_check_rom(pdev);
+	if (rom) {
+		/* perform chip erase first */
+		renesas_rom_erase(pdev);
+
+		/* lets try loading fw on ROM first */
+		rom = renesas_setup_rom(pdev, fw);
+		if (!rom) {
+			dev_dbg(&pdev->dev,
+				"ROM load failed, falling back on FW load\n");
+		} else {
+			dev_dbg(&pdev->dev,
+				"ROM load success\n");
+			goto exit;
+		}
+	}
 
 	err = renesas_fw_download(pdev, fw);
+
+exit:
 	if (err)
 		dev_err(&pdev->dev, "firmware failed to download (%d).", err);
 	return err;