[PATCH V3 2/4] mmc: debugfs: Add debug fs entry for mmc driver

[Shaik Sajida Bhanu]

Add debug fs entry to query eMMC and SD card errors statistics

Signed-off-by: Shaik Sajida Bhanu <quic_c_sbhanu@xxxxxxxxxxx>
Signed-off-by: Liangliang Lu <luliang@xxxxxxxxxxxxxx>
Signed-off-by: Sayali Lokhande <sayalil@xxxxxxxxxxxxxx>
Signed-off-by: Bao D. Nguyen <nguyenb@xxxxxxxxxxxxxx>
---
 drivers/mmc/core/debugfs.c | 81 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 81 insertions(+)

diff --git a/drivers/mmc/core/debugfs.c b/drivers/mmc/core/debugfs.c
index 3fdbc80..f4cb594 100644
--- a/drivers/mmc/core/debugfs.c
+++ b/drivers/mmc/core/debugfs.c
@@ -223,6 +223,82 @@ 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;
+
+	if (!host)
+		return -EINVAL;
+
+	*val = host->err_state ? 1 : 0;
+
+	return 0;
+}
+
+DEFINE_SIMPLE_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;
+	const char *desc[MMC_ERR_MAX] = {
+		[MMC_ERR_CMD_TIMEOUT] = "Command Timeout Occurred",
+		[MMC_ERR_CMD_CRC] = "Command CRC Errors Occurred",
+		[MMC_ERR_DAT_TIMEOUT] = "Data Timeout Occurred",
+		[MMC_ERR_DAT_CRC] = "Data CRC Errors Occurred",
+		[MMC_ERR_AUTO_CMD] = "Auto-Cmd Error Occurred",
+		[MMC_ERR_ADMA] = "ADMA Error Occurred",
+		[MMC_ERR_TUNING] = "Tuning Error Occurred",
+		[MMC_ERR_CMDQ_RED] = "CMDQ RED Errors",
+		[MMC_ERR_CMDQ_GCE] = "CMDQ GCE Errors",
+		[MMC_ERR_CMDQ_ICCE] = "CMDQ ICCE Errors",
+		[MMC_ERR_REQ_TIMEOUT] = "Request Timedout",
+		[MMC_ERR_CMDQ_REQ_TIMEOUT] = "CMDQ Request Timedout",
+		[MMC_ERR_ICE_CFG] = "ICE Config Errors",
+	};
+	int i;
+
+	if (!host)
+		return -EINVAL;
+
+	if (!host->err_stats_enabled) {
+		seq_printf(file, "Not supported by driver\n");
+		return 0;
+	}
+
+	for (i = 0; i < MMC_ERR_MAX; i++) {
+		if (desc[i])
+			seq_printf(file, "# %s:\t %d\n",
+					desc[i], host->err_stats[i]);
+	}
+
+	return 0;
+}
+
+static int mmc_err_stats_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, mmc_err_stats_show, inode->i_private);
+}
+
+static ssize_t mmc_err_stats_write(struct file *filp, const char __user *ubuf,
+				   size_t cnt, loff_t *ppos)
+{
+	struct mmc_host *host = filp->f_mapping->host->i_private;
+
+	if (!host)
+		return -EINVAL;
+
+	pr_debug("%s: Resetting MMC error statistics\n", __func__);
+	memset(host->err_stats, 0, sizeof(host->err_stats));
+
+	return cnt;
+}
+
+static const struct file_operations mmc_err_stats_fops = {
+	.open	= mmc_err_stats_open,
+	.read	= seq_read,
+	.write	= mmc_err_stats_write,
+};
+
 void mmc_add_host_debugfs(struct mmc_host *host)
 {
 	struct dentry *root;
@@ -236,6 +312,11 @@ 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("err_state", 0600, root, host,
+		&mmc_err_state);
+	debugfs_create_file("err_stats", 0600, root, host,
+		&mmc_err_stats_fops);
+
 #ifdef CONFIG_FAIL_MMC_REQUEST
 	if (fail_request)
 		setup_fault_attr(&fail_default_attr, fail_request);
-- 
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