sandbox: mmc: Support a backing file

Provide a way for sandbox MMC to present data from a backing file. This
allows a filesystem to be created on the host and easily served via an
emulated mmc device.

Signed-off-by: Simon Glass <sjg@chromium.org>

diff --git a/doc/device-tree-bindings/mmc/sandbox,mmc.txt b/doc/device-tree-bindings/mmc/sandbox,mmc.txt
new file mode 100644 (file)
index 0000000..1170bcd
--- /dev/null
+++ b/doc/device-tree-bindings/mmc/sandbox,mmc.txt
@@ -0,0 +1,18 @@
+Sandbox MMC
+===========
+
+Required properties:
+- compatible : "sandbox,mmc"
+
+Optional properties:
+- filename : Name of backing file, if any. This is mapped into the MMC device
+    so can be used to provide a filesystem or other test data
+
+
+Example
+-------
+
+mmc2 {
+       compatible = "sandbox,mmc";
+       non-removable;
+};

diff --git a/drivers/mmc/sandbox_mmc.c b/drivers/mmc/sandbox_mmc.c
index 895fbff..451fe4a 100644 (file)
--- a/drivers/mmc/sandbox_mmc.c
+++ b/drivers/mmc/sandbox_mmc.c
@@ -9,23 +9,26 @@
 #include <errno.h>
 #include <fdtdec.h>
 #include <log.h>
+#include <malloc.h>
 #include <mmc.h>
+#include <os.h>
 #include <asm/test.h>
 
 struct sandbox_mmc_plat {
        struct mmc_config cfg;
        struct mmc mmc;
+       const char *fname;
 };
 
-#define MMC_CSIZE 0
-#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)
-#define MMC_CAPACITY (((MMC_CSIZE + 1) << (MMC_CMULT + 2)) \
-                     * MMC_BL_LEN) /* 1 MiB */
+#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)
+#define SIZE_MULTIPLE          ((1 << (MMC_CMULT + 2)) * MMC_BL_LEN)
 
 struct sandbox_mmc_priv {
-       u8 buf[MMC_CAPACITY];
+       char *buf;
+       int csize;      /* CSIZE value to report */
+       int size;
 };
 
 /**
@@ -60,8 +63,8 @@ static int sandbox_mmc_send_cmd(struct udevice *dev, struct mmc_cmd *cmd,
        case MMC_CMD_SEND_CSD:
                cmd->response[0] = 0;
                cmd->response[1] = (MMC_BL_LEN_SHIFT << 16) |
-                                  ((MMC_CSIZE >> 16) & 0x3f);
-               cmd->response[2] = (MMC_CSIZE & 0xffff) << 16;
+                                  ((priv->csize >> 16) & 0x3f);
+               cmd->response[2] = (priv->csize & 0xffff) << 16;
                cmd->response[3] = 0;
                break;
        case SD_CMD_SWITCH_FUNC: {
@@ -143,6 +146,8 @@ static int sandbox_mmc_of_to_plat(struct udevice *dev)
        struct blk_desc *blk;
        int ret;
 
+       plat->fname = dev_read_string(dev, "filename");
+
        ret = mmc_of_parse(dev, cfg);
        if (ret)
                return ret;
@@ -156,10 +161,46 @@ static int sandbox_mmc_of_to_plat(struct udevice *dev)
 static int sandbox_mmc_probe(struct udevice *dev)
 {
        struct sandbox_mmc_plat *plat = dev_get_plat(dev);
+       struct sandbox_mmc_priv *priv = dev_get_priv(dev);
+       int ret;
+
+       if (plat->fname) {
+               ret = os_map_file(plat->fname, OS_O_RDWR | OS_O_CREAT,
+                                 (void **)&priv->buf, &priv->size);
+               if (ret) {
+                       log_err("%s: Unable to map file '%s'\n", dev->name,
+                               plat->fname);
+                       return ret;
+               }
+               priv->csize = priv->size / SIZE_MULTIPLE - 1;
+       } else {
+               priv->csize = 0;
+               priv->size = (priv->csize + 1) * SIZE_MULTIPLE; /* 1 MiB */
+
+               priv->buf = malloc(priv->size);
+               if (!priv->buf) {
+                       log_err("%s: Not enough memory (%x bytes)\n",
+                               dev->name, priv->size);
+                       return -ENOMEM;
+               }
+       }
 
        return mmc_init(&plat->mmc);
 }
 
+static int sandbox_mmc_remove(struct udevice *dev)
+{
+       struct sandbox_mmc_plat *plat = dev_get_plat(dev);
+       struct sandbox_mmc_priv *priv = dev_get_priv(dev);
+
+       if (plat->fname)
+               os_unmap(priv->buf, priv->size);
+       else
+               free(priv->buf);
+
+       return 0;
+}
+
 static int sandbox_mmc_bind(struct udevice *dev)
 {
        struct sandbox_mmc_plat *plat = dev_get_plat(dev);
@@ -196,6 +237,7 @@ U_BOOT_DRIVER(mmc_sandbox) = {
        .unbind         = sandbox_mmc_unbind,
        .of_to_plat     = sandbox_mmc_of_to_plat,
        .probe          = sandbox_mmc_probe,
+       .remove         = sandbox_mmc_remove,
        .priv_auto = sizeof(struct sandbox_mmc_priv),
        .plat_auto = sizeof(struct sandbox_mmc_plat),
 };