[PATCH 1/3] [01/03] mmc: solve DMA boundary limitation of CQHCI driver

[Jyan Chou]

Due to synopsys data book's description, it had a limitation
while using DMA that buffer size and start address must not
exceed 128 MB.

We add an option setup_tran_desc to make tran_desc setting flexible.

Signed-off-by: Jyan Chou <jyanchou@xxxxxxxxxxx>

---
v0 to v1 change:
1. Separate different patch supports into single patch.
---
 drivers/mmc/host/cqhci-core.c | 5 +++++
 drivers/mmc/host/cqhci.h      | 2 ++
 2 files changed, 7 insertions(+)

diff --git a/drivers/mmc/host/cqhci-core.c b/drivers/mmc/host/cqhci-core.c
index b3d7d6d8d654..4d6fb228a21e 100644
--- a/drivers/mmc/host/cqhci-core.c
+++ b/drivers/mmc/host/cqhci-core.c
@@ -516,6 +516,11 @@ static int cqhci_prep_tran_desc(struct mmc_request *mrq,
 
 	desc = get_trans_desc(cq_host, tag);
 
+	if (cq_host->ops->setup_tran_desc) {
+		cq_host->ops->setup_tran_desc(data, cq_host, desc, sg_count);
+		return 0;
+	}
+
 	for_each_sg(data->sg, sg, sg_count, i) {
 		addr = sg_dma_address(sg);
 		len = sg_dma_len(sg);
diff --git a/drivers/mmc/host/cqhci.h b/drivers/mmc/host/cqhci.h
index 1a12e40a02e6..cb3dfb161c54 100644
--- a/drivers/mmc/host/cqhci.h
+++ b/drivers/mmc/host/cqhci.h
@@ -289,6 +289,8 @@ struct cqhci_host_ops {
 				 u64 *data);
 	void (*pre_enable)(struct mmc_host *mmc);
 	void (*post_disable)(struct mmc_host *mmc);
+	void (*setup_tran_desc)(struct mmc_data *data,
+		struct cqhci_host *cq_host, u8 *desc, int sg_count);
 #ifdef CONFIG_MMC_CRYPTO
 	int (*program_key)(struct cqhci_host *cq_host,
 			   const union cqhci_crypto_cfg_entry *cfg, int slot);
-- 
2.42.0