mmc: debugfs: Add debug fs error state entry for mmc driver

Add debug fs entry error state to query eMMC and SD card errors statistics.
If any errors occurred in eMMC and SD card driver level then
err_state value will be set to 1.
Signed-off-by: Liangliang Lu <quic_luliang@quicinc.com>
Signed-off-by: Sayali Lokhande <quic_sayalil@quicinc.com>
Signed-off-by: Bao D. Nguyen <quic_nguyenb@quicinc.com>
Signed-off-by: Shaik Sajida Bhanu <quic_c_sbhanu@quicinc.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/1653674036-21829-5-git-send-email-quic_c_sbhanu@quicinc.comSigned-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/core/debugfs.c

@@ -223,6 +223,27 @@ static int mmc_clock_opt_set(void *data, u64 val)
 DEFINE_DEBUGFS_ATTRIBUTE(mmc_clock_fops, mmc_clock_opt_get, mmc_clock_opt_set,
 	"%llu\n");
 
+static int mmc_err_state_get(void *data, u64 *val)
+{
+	struct mmc_host *host = data;
+	int i;
+
+	if (!host)
+		return -EINVAL;
+
+	*val = 0;
+	for (i = 0; i < MMC_ERR_MAX; i++) {
+		if (host->err_stats[i]) {
+			*val = 1;
+			break;
+		}
+	}
+
+	return 0;
+}
+
+DEFINE_DEBUGFS_ATTRIBUTE(mmc_err_state, mmc_err_state_get, NULL, "%llu\n");
+
 static int mmc_err_stats_show(struct seq_file *file, void *data)
 {
 	struct mmc_host *host = (struct mmc_host *)file->private;
@@ -289,6 +310,8 @@ void mmc_add_host_debugfs(struct mmc_host *host)
 	debugfs_create_file_unsafe("clock", S_IRUSR | S_IWUSR, root, host,
 				   &mmc_clock_fops);
 
+	debugfs_create_file_unsafe("err_state", 0600, root, host,
+			    &mmc_err_state);
 	debugfs_create_file("err_stats", 0600, root, host,
 			    &mmc_err_stats_fops);