[PATCH v2] mhi: host: Add standard ELF header image download functionality

[Qiang Yu]

From: Mayank Rana <quic_mrana@xxxxxxxxxxx>

Some devices (e.g. WLAN chips) are unable to handle the non-standard ELF
format of the FBC image and thus need special handling of the FBC image.

Add standard_elf_image flag which makes decision in terms of how FBC image
based AMSS image is being downloaded with connected endpoint.
FBC image is having two image combine: SBL image + AMSS image.
1. FBC image download using legacy single ELF header image format:
- SBL image: 512KB of FBC image is downloaded using BHI.
- AMSS image: full FBC image is downloaded using BHIe.
2. FBC image download using separate ELF header image format:
- SBL image: 512 KB of FBC image is downloaded using BHI.
- AMSS image: 512 KB onward FBC image is downloaded using BHIe.
There is no change for SBL image download. Although AMSS image start
address is end address of SBL image while using separate ELF header format.

Signed-off-by: Mayank Rana <quic_mrana@xxxxxxxxxxx>
[quic_qianyu@xxxxxxxxxxx: Update commit message, minor updates]
Signed-off-by: Qiang Yu <quic_qianyu@xxxxxxxxxxx>
---
v1->v2: modify commit message
	correct author
	rebase on latest mhi-next branch, resolve conflicts

 drivers/bus/mhi/host/boot.c | 7 +++++++
 include/linux/mhi.h         | 2 ++
 2 files changed, 9 insertions(+)

diff --git a/drivers/bus/mhi/host/boot.c b/drivers/bus/mhi/host/boot.c
index edc0ec5..586d551 100644
--- a/drivers/bus/mhi/host/boot.c
+++ b/drivers/bus/mhi/host/boot.c
@@ -495,6 +495,13 @@ void mhi_fw_load_handler(struct mhi_controller *mhi_cntrl)
 	 * device transitioning into MHI READY state
 	 */
 	if (mhi_cntrl->fbc_download) {
+		dev_dbg(dev, "standard_elf_image: %s\n",
+				(mhi_cntrl->standard_elf_image ? "True" : "False"));
+		if (mhi_cntrl->standard_elf_image) {
+			fw_data = firmware->data + mhi_cntrl->sbl_size;
+			fw_sz = fw_sz - mhi_cntrl->sbl_size;
+		}
+
 		ret = mhi_alloc_bhie_table(mhi_cntrl, &mhi_cntrl->fbc_image, fw_sz);
 		if (ret) {
 			release_firmware(firmware);
diff --git a/include/linux/mhi.h b/include/linux/mhi.h
index 039943e..e065101 100644
--- a/include/linux/mhi.h
+++ b/include/linux/mhi.h
@@ -310,6 +310,7 @@ struct mhi_controller_config {
  * @reg_len: Length of the MHI MMIO region (required)
  * @fbc_image: Points to firmware image buffer
  * @rddm_image: Points to RAM dump buffer
+ * @standard_elf_image: Flag to make decision about firmware download start address (optional)
  * @mhi_chan: Points to the channel configuration table
  * @lpm_chans: List of channels that require LPM notifications
  * @irq: base irq # to request (required)
@@ -456,6 +457,7 @@ struct mhi_controller {
 	bool bounce_buf;
 	bool fbc_download;
 	bool wake_set;
+	bool standard_elf_image;
 	unsigned long irq_flags;
 	u32 mru;
 };
-- 
2.7.4