Support SEND_STATUS command

mmc status get </path/to/mmcblkX>
Signed-off-by: Ben Gardiner <bengardiner@nanometrics.ca>
Signed-off-by: Chris Ball <cjb@laptop.org>

mmc.c

@@ -70,6 +70,11 @@ static struct Command commands[] = {
 		"Set the eMMC data sector size to 4KB by disabling emulation on\n<device>.",
 	  NULL
 	},
+	{ do_status_get, -1,
+	  "status get", "<device>\n"
+	  "Print the response to STATUS_SEND (CMD13).",
+	  NULL
+	},
 	{ do_write_boot_en, -3,
 	  "bootpart enable", "<boot_partition> " "<send_ack> " "<device>\n"
 		"Enable the boot partition for the <device>.\nTo receive acknowledgment of boot from the card set <send_ack>\nto 1, else set it to 0.",

mmc.h

@@ -26,6 +26,8 @@
 /* From kernel linux/mmc/mmc.h */
 #define MMC_SWITCH		6	/* ac	[31:0] See below	R1b */
 #define MMC_SEND_EXT_CSD	8	/* adtc				R1  */
+#define MMC_SEND_STATUS		13	/* ac   [31:16] RCA        R1  */
+#define R1_SWITCH_ERROR   (1 << 7)  /* sx, c */
 #define MMC_SWITCH_MODE_WRITE_BYTE	0x03	/* Set target to value */
 
 /*

mmc_cmds.c

@@ -72,6 +72,25 @@ int write_extcsd_value(int fd, __u8 index, __u8 value)
 	return ret;
 }
 
+int send_status(int fd, __u32 *response)
+{
+	int ret = 0;
+	struct mmc_ioc_cmd idata;
+
+	memset(&idata, 0, sizeof(idata));
+	idata.opcode = MMC_SEND_STATUS;
+	idata.arg = (1 << 16);
+	idata.flags = MMC_RSP_R1 | MMC_CMD_AC;
+
+	ret = ioctl(fd, MMC_IOC_CMD, &idata);
+	if (ret)
+	perror("ioctl");
+
+	*response = idata.response[0];
+
+	return ret;
+}
+
 void print_writeprotect_status(__u8 *ext_csd)
 {
 	__u8 reg;
@@ -377,6 +396,34 @@ int do_write_bkops_en(int nargs, char **argv)
 	return ret;
 }
 
+int do_status_get(int nargs, char **argv)
+{
+	__u32 response;
+	int fd, ret;
+	char *device;
+
+	CHECK(nargs != 2, "Usage: mmc status get </path/to/mmcblkX>\n",
+		exit(1));
+
+	device = argv[1];
+
+	fd = open(device, O_RDWR);
+	if (fd < 0) {
+		perror("open");
+		exit(1);
+	}
+
+	ret = send_status(fd, &response);
+	if (ret) {
+		fprintf(stderr, "Could not read response to SEND_STATUS from %s\n", device);
+		exit(1);
+	}
+
+	printf("SEND_STATUS response: 0x%08x\n", response);
+
+	return ret;
+}
+
 int do_read_extcsd(int nargs, char **argv)
 {
 	__u8 ext_csd[512], ext_csd_rev, reg;

mmc_cmds.h

@@ -25,3 +25,4 @@ int do_write_bkops_en(int nargs, char **argv);
 int do_hwreset_en(int nargs, char **argv);
 int do_hwreset_dis(int nargs, char **argv);
 int do_sanitize(int nargs, char **argv);
+int do_status_get(int nargs, char **argv);