[U-Boot] [PATCH 21/23] dm: mmc: sandbox: Add an SD-card emulation

[Simon Glass]

Add an emulation of an SD card to sandbox, allowing MMC to be used in tests.
The emulation is very simple, supporting only card detection and reading
test data.

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

 drivers/mmc/Kconfig       |  11 +++-
 drivers/mmc/sandbox_mmc.c | 134 +++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 143 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
index 4d3df11..c80efc3 100644
--- a/drivers/mmc/Kconfig
+++ b/drivers/mmc/Kconfig
@@ -2,7 +2,7 @@ menu "MMC Host controller Support"
 
 config MMC
 	bool "Enable MMC support"
-	depends on ARCH_SUNXI
+	depends on ARCH_SUNXI || SANDBOX
 	help
 	  TODO: Move all architectures to use this option
 
@@ -58,4 +58,13 @@ config MMC_UNIPHIER
 	help
 	  This selects support for the SD/MMC Host Controller on UniPhier SoCs.
 
+config SANDBOX_MMC
+	bool "Sandbox MMC support"
+	depends on MMC && SANDBOX
+	help
+	  This select a dummy sandbox MMC driver. At present this does nothing
+	  other than allow sandbox to be build with MMC support. This
+	  improves build coverage for sandbox and makes it easier to detect
+	  MMC build errors with sandbox.
+
 endmenu
diff --git a/drivers/mmc/sandbox_mmc.c b/drivers/mmc/sandbox_mmc.c
index f4646a8..7da059c 100644
--- a/drivers/mmc/sandbox_mmc.c
+++ b/drivers/mmc/sandbox_mmc.c
@@ -8,18 +8,150 @@
 #include <common.h>
 #include <dm.h>
 #include <errno.h>
+#include <fdtdec.h>
 #include <mmc.h>
 #include <asm/test.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
+struct sandbox_mmc_plat {
+	struct mmc_config cfg;
+	struct mmc mmc;
+};
+
+/**
+ * sandbox_mmc_send_cmd() - Emulate SD commands
+ *
+ * This emulate an SD card version 2. Single-block reads result in zero data.
+ * Multiple-block reads return a test string.
+ */
+static int sandbox_mmc_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd,
+				struct mmc_data *data)
+{
+	switch (cmd->cmdidx) {
+	case MMC_CMD_ALL_SEND_CID:
+		break;
+	case SD_CMD_SEND_RELATIVE_ADDR:
+		cmd->response[0] = 0 << 16; /* mmc->rca */
+	case MMC_CMD_GO_IDLE_STATE:
+		break;
+	case SD_CMD_SEND_IF_COND:
+		cmd->response[0] = 0xaa;
+		break;
+	case MMC_CMD_SEND_STATUS:
+		cmd->response[0] = MMC_STATUS_RDY_FOR_DATA;
+		break;
+	case MMC_CMD_SELECT_CARD:
+		break;
+	case MMC_CMD_SEND_CSD:
+		cmd->response[0] = 0;
+		cmd->response[1] = 10 << 16;	/* 1 << block_len */
+		break;
+	case SD_CMD_SWITCH_FUNC: {
+		u32 *resp = (u32 *)data->dest;
+
+		resp[7] = cpu_to_be32(SD_HIGHSPEED_BUSY);
+		break;
+	}
+	case MMC_CMD_READ_SINGLE_BLOCK:
+		memset(data->dest, '\0', data->blocksize);
+		break;
+	case MMC_CMD_READ_MULTIPLE_BLOCK:
+		strcpy(data->dest, "this is a test");
+		break;
+	case MMC_CMD_STOP_TRANSMISSION:
+		break;
+	case SD_CMD_APP_SEND_OP_COND:
+		cmd->response[0] = OCR_BUSY | OCR_HCS;
+		cmd->response[1] = 0;
+		cmd->response[2] = 0;
+		break;
+	case MMC_CMD_APP_CMD:
+		break;
+	case MMC_CMD_SET_BLOCKLEN:
+		debug("block len %d\n", cmd->cmdarg);
+		break;
+	case SD_CMD_APP_SEND_SCR: {
+		u32 *scr = (u32 *)data->dest;
+
+		scr[0] = cpu_to_be32(2 << 24 | 1 << 15);  /* SD version 3 */
+		break;
+	}
+	default:
+		debug("%s: Unknown command %d\n", __func__, cmd->cmdidx);
+		break;
+	}
+
+	return 0;
+}
+
+static void sandbox_mmc_set_ios(struct mmc *mmc)
+{
+}
+
+static int sandbox_mmc_init(struct mmc *mmc)
+{
+	return 0;
+}
+
+static int sandbox_mmc_getcd(struct mmc *mmc)
+{
+	return 1;
+}
+
+static const struct mmc_ops sandbox_mmc_ops = {
+	.send_cmd = sandbox_mmc_send_cmd,
+	.set_ios = sandbox_mmc_set_ios,
+	.init = sandbox_mmc_init,
+	.getcd = sandbox_mmc_getcd,
+};
+
+int sandbox_mmc_probe(struct udevice *dev)
+{
+	struct sandbox_mmc_plat *plat = dev_get_platdata(dev);
+
+	return mmc_init(&plat->mmc);
+}
+
+int sandbox_mmc_bind(struct udevice *dev)
+{
+	struct sandbox_mmc_plat *plat = dev_get_platdata(dev);
+	struct mmc_config *cfg = &plat->cfg;
+	int ret;
+
+	cfg->name = dev->name;
+	cfg->ops = &sandbox_mmc_ops;
+	cfg->host_caps = MMC_MODE_HS_52MHz | MMC_MODE_HS | MMC_MODE_8BIT;
+	cfg->voltages = MMC_VDD_165_195 | MMC_VDD_32_33 | MMC_VDD_33_34;
+	cfg->f_min = 1000000;
+	cfg->f_max = 52000000;
+	cfg->b_max = U32_MAX;
+
+	ret = mmc_bind(dev, &plat->mmc, cfg);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+int sandbox_mmc_unbind(struct udevice *dev)
+{
+	mmc_unbind(dev);
+
+	return 0;
+}
+
 static const struct udevice_id sandbox_mmc_ids[] = {
 	{ .compatible = "sandbox,mmc" },
 	{ }
 };
 
-U_BOOT_DRIVER(warm_mmc_sandbox) = {
+U_BOOT_DRIVER(mmc_sandbox) = {
 	.name		= "mmc_sandbox",
 	.id		= UCLASS_MMC,
 	.of_match	= sandbox_mmc_ids,
+	.bind		= sandbox_mmc_bind,
+	.unbind		= sandbox_mmc_unbind,
+	.probe		= sandbox_mmc_probe,
+	.platdata_auto_alloc_size = sizeof(struct sandbox_mmc_plat),
 };
-- 
2.8.0.rc3.226.g39d4020