dm: mmc: Allow sandbox emulator to build without writes

When MMC_WRITE is disabled this driver produced a build error. Fix this.

Also update a comment while we are here.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>

diff --git a/drivers/mmc/sandbox_mmc.c b/drivers/mmc/sandbox_mmc.c
index 451fe4a..ba79a55 100644 (file)
--- a/drivers/mmc/sandbox_mmc.c
+++ b/drivers/mmc/sandbox_mmc.c
@@ -23,6 +23,8 @@ struct sandbox_mmc_plat {
 #define MMC_CMULT              8 /* 8 because the card is high-capacity */
 #define MMC_BL_LEN_SHIFT       10
 #define MMC_BL_LEN             BIT(MMC_BL_LEN_SHIFT)
+
+/* Granularity of priv->csize - this is 1MB */
 #define SIZE_MULTIPLE          ((1 << (MMC_CMULT + 2)) * MMC_BL_LEN)
 
 struct sandbox_mmc_priv {
@@ -41,7 +43,6 @@ static int sandbox_mmc_send_cmd(struct udevice *dev, struct mmc_cmd *cmd,
                                struct mmc_data *data)
 {
        struct sandbox_mmc_priv *priv = dev_get_priv(dev);
-       struct mmc *mmc = mmc_get_mmc_dev(dev);
        static ulong erase_start, erase_end;
 
        switch (cmd->cmdidx) {
@@ -95,10 +96,15 @@ static int sandbox_mmc_send_cmd(struct udevice *dev, struct mmc_cmd *cmd,
        case SD_CMD_ERASE_WR_BLK_END:
                erase_end = cmd->cmdarg;
                break;
-       case MMC_CMD_ERASE:
+#if CONFIG_IS_ENABLED(MMC_WRITE)
+       case MMC_CMD_ERASE: {
+               struct mmc *mmc = mmc_get_mmc_dev(dev);
+
                memset(&priv->buf[erase_start * mmc->write_bl_len], '\0',
                       (erase_end - erase_start + 1) * mmc->write_bl_len);
                break;
+       }
+#endif
        case SD_CMD_APP_SEND_OP_COND:
                cmd->response[0] = OCR_BUSY | OCR_HCS;
                cmd->response[1] = 0;