mmc: sh_mobile_sdhi: properly document R-Car versions

Replace hardcoded values with meaningful names and document what we
know.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/host/sh_mobile_sdhi.c b/drivers/mmc/host/sh_mobile_sdhi.c
index f750f94..c3b651b 100644 (file)
--- a/drivers/mmc/host/sh_mobile_sdhi.c
+++ b/drivers/mmc/host/sh_mobile_sdhi.c
@@ -39,6 +39,12 @@
 
 #define EXT_ACC           0xe4
 
+#define SDHI_VER_GEN2_SDR50    0x490c
+/* very old datasheets said 0x490c for SDR104, too. They are wrong! */
+#define SDHI_VER_GEN2_SDR104   0xcb0d
+#define SDHI_VER_GEN3_SD       0xcc10
+#define SDHI_VER_GEN3_SDMMC    0xcd10
+
 #define host_to_priv(host) container_of((host)->pdata, struct sh_mobile_sdhi, mmc_data)
 
 struct sh_mobile_sdhi_of_data {
@@ -109,14 +115,14 @@ static void sh_mobile_sdhi_sdbuf_width(struct tmio_mmc_host *host, int width)
         *      sh_mobile_sdhi_of_data :: dma_buswidth
         */
        switch (sd_ctrl_read16(host, CTL_VERSION)) {
-       case 0x490C:
+       case SDHI_VER_GEN2_SDR50:
                val = (width == 32) ? 0x0001 : 0x0000;
                break;
-       case 0xCB0D:
+       case SDHI_VER_GEN2_SDR104:
                val = (width == 32) ? 0x0000 : 0x0001;
                break;
-       case 0xCC10: /* Gen3, SD only */
-       case 0xCD10: /* Gen3, SD + MMC */
+       case SDHI_VER_GEN3_SD:
+       case SDHI_VER_GEN3_SDMMC:
                if (width == 64)
                        val = 0x0000;
                else if (width == 32)