mmc: stm32_sdmmc2: correctly manage block size

DBLOCKSIZE should be filled such as the data size is 2^DBLOCKSIZE.
Hence it is calculated with __builtin_ctz.

Change-Id: Id6b5ff9b594afc4fc523a388011beed307e6abd1
Signed-off-by: Yann Gautier <yann.gautier@st.com>

drivers/st/mmc/stm32_sdmmc2.c

@@ -71,20 +71,14 @@
 #define SDMMC_DCTRLR_DTEN		BIT(0)
 #define SDMMC_DCTRLR_DTDIR		BIT(1)
 #define SDMMC_DCTRLR_DTMODE		GENMASK(3, 2)
-#define SDMMC_DCTRLR_DBLOCKSIZE_0	BIT(4)
-#define SDMMC_DCTRLR_DBLOCKSIZE_1	BIT(5)
-#define SDMMC_DCTRLR_DBLOCKSIZE_3	BIT(7)
 #define SDMMC_DCTRLR_DBLOCKSIZE		GENMASK(7, 4)
+#define SDMMC_DCTRLR_DBLOCKSIZE_SHIFT	4
 #define SDMMC_DCTRLR_FIFORST		BIT(13)
 
 #define SDMMC_DCTRLR_CLEAR_MASK		(SDMMC_DCTRLR_DTEN | \
 					 SDMMC_DCTRLR_DTDIR | \
 					 SDMMC_DCTRLR_DTMODE | \
 					 SDMMC_DCTRLR_DBLOCKSIZE)
-#define SDMMC_DBLOCKSIZE_8		(SDMMC_DCTRLR_DBLOCKSIZE_0 | \
-					 SDMMC_DCTRLR_DBLOCKSIZE_1)
-#define SDMMC_DBLOCKSIZE_512		(SDMMC_DCTRLR_DBLOCKSIZE_0 | \
-					 SDMMC_DCTRLR_DBLOCKSIZE_3)
 
 /* SDMMC status register */
 #define SDMMC_STAR_CCRCFAIL		BIT(0)
@@ -464,11 +458,14 @@ static int stm32_sdmmc2_prepare(int lba, uintptr_t buf, size_t size)
 	int ret;
 	uintptr_t base = sdmmc2_params.reg_base;
 	uint32_t data_ctrl = SDMMC_DCTRLR_DTDIR;
+	uint32_t arg_size;
 
-	if (size == 8U) {
-		data_ctrl |= SDMMC_DBLOCKSIZE_8;
+	assert(size != 0U);
+
+	if (size > MMC_BLOCK_SIZE) {
+		arg_size = MMC_BLOCK_SIZE;
 	} else {
-		data_ctrl |= SDMMC_DBLOCKSIZE_512;
+		arg_size = size;
 	}
 
 	sdmmc2_params.use_dma = plat_sdmmc2_use_dma(base, buf);
@@ -487,12 +484,7 @@ static int stm32_sdmmc2_prepare(int lba, uintptr_t buf, size_t size)
 	zeromem(&cmd, sizeof(struct mmc_cmd));
 
 	cmd.cmd_idx = MMC_CMD(16);
-	if (size > MMC_BLOCK_SIZE) {
-		cmd.cmd_arg = MMC_BLOCK_SIZE;
-	} else {
-		cmd.cmd_arg = size;
-	}
-
+	cmd.cmd_arg = arg_size;
 	cmd.resp_type = MMC_RESPONSE_R1;
 
 	ret = stm32_sdmmc2_send_cmd(&cmd);
@@ -514,6 +506,8 @@ static int stm32_sdmmc2_prepare(int lba, uintptr_t buf, size_t size)
 		flush_dcache_range(buf, size);
 	}
 
+	data_ctrl |= __builtin_ctz(arg_size) << SDMMC_DCTRLR_DBLOCKSIZE_SHIFT;
+
 	mmio_clrsetbits_32(base + SDMMC_DCTRLR,
 			   SDMMC_DCTRLR_CLEAR_MASK,
 			   data_ctrl);