[PATCH v13 4/5] usb: renesas-xhci: Add ROM loader for uPD720201

[Vinod Koul <vkoul@kernel.org>]

uPD720201 supports ROM and allows software to program the ROM and boot
from it. Add support for detecting if ROM is present, if so load the ROM
if not programmed earlier.

Signed-off-by: Vinod Koul <vkoul@kernel.org>
---
 drivers/usb/host/xhci-pci-renesas.c | 294 +++++++++++++++++++++++++++-
 1 file changed, 287 insertions(+), 7 deletions(-)

diff --git a/drivers/usb/host/xhci-pci-renesas.c b/drivers/usb/host/xhci-pci-renesas.c
index 88341d79b651..f7d2445d30ec 100644
--- a/drivers/usb/host/xhci-pci-renesas.c
+++ b/drivers/usb/host/xhci-pci-renesas.c
@@ -50,13 +50,33 @@
 #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;
+	}
+	dev_err(&pdev->dev, "FW has invalid version :%d\n", version);
+	return -EINVAL;
+}
+
 static int renesas_fw_download_image(struct pci_dev *dev,
-				     const u32 *fw, size_t step)
+				     const u32 *fw, size_t step, bool rom)
 {
 	size_t i;
 	int err;
 	u8 fw_status;
 	bool data0_or_data1;
+	u32 status_reg;
+
+	if (rom)
+		status_reg = RENESAS_ROM_STATUS_MSB;
+	else
+		status_reg = RENESAS_FW_STATUS_MSB;
 
 	/*
 	 * The hardware does alternate between two 32-bit pages.
@@ -68,8 +88,7 @@ static int renesas_fw_download_image(struct pci_dev *dev,
 
 	/* step+1. Read "Set DATAX" and confirm it is cleared. */
 	for (i = 0; i < RENESAS_RETRY; i++) {
-		err = pci_read_config_byte(dev, RENESAS_FW_STATUS_MSB,
-					   &fw_status);
+		err = pci_read_config_byte(dev, status_reg, &fw_status);
 		if (err) {
 			dev_err(&dev->dev, "Read Status failed: %d\n",
 				pcibios_err_to_errno(err));
@@ -101,8 +120,7 @@ static int renesas_fw_download_image(struct pci_dev *dev,
 	udelay(100);
 
 	/* step+3. Set "Set DATAX". */
-	err = pci_write_config_byte(dev, RENESAS_FW_STATUS_MSB,
-				    BIT(data0_or_data1));
+	err = pci_write_config_byte(dev, status_reg, BIT(data0_or_data1));
 	if (err) {
 		dev_err(&dev->dev, "Write config for DATAX failed: %d\n",
 			pcibios_err_to_errno(err));
@@ -152,10 +170,84 @@ 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
@@ -243,7 +335,7 @@ static int renesas_fw_download(struct pci_dev *pdev,
 
 	/* 1 - 10 follow one step after the other. */
 	for (i = 0; i < fw->size / 4; i++) {
-		err = renesas_fw_download_image(pdev, fw_data, i);
+		err = renesas_fw_download_image(pdev, fw_data, i, false);
 		if (err) {
 			dev_err(&pdev->dev,
 				"Firmware Download Step %zd failed at position %zd bytes with (%d).",
@@ -311,11 +403,199 @@ 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_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_fw_download_image(pdev, fw_data, i, true);
+		if (err) {
+			dev_err(&pdev->dev,
+				"ROM Download Step %d failed at position %d bytes with (%d)\n",
+				 i, i * 4, err);
+			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;
-- 
2.25.4