drivers: thermal: tsens: Add debugfs support

Dump some basic version info and sensor details into debugfs. Example
from qcs404 below:

--(/sys/kernel/debug) $ ls tsens/
4a9000.thermal-sensor  version
--(/sys/kernel/debug) $ cat tsens/version
1.4.0
--(/sys/kernel/debug) $ cat tsens/4a9000.thermal-sensor/sensors
max: 11
num: 10

      id    slope   offset
------------------------
       0     3200   404000
       1     3200   404000
       2     3200   404000
       3     3200   404000
       4     3200   404000
       5     3200   404000
       6     3200   404000
       7     3200   404000
       8     3200   404000
       9     3200   404000

Signed-off-by: Amit Kucheria <amit.kucheria@linaro.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/16e39c1bbfc18b5cf6274620cd72cc63205f53a5.1572526427.git.amit.kucheria@linaro.org

drivers/thermal/qcom/tsens-common.c

@@ -3,6 +3,7 @@
  * Copyright (c) 2015, The Linux Foundation. All rights reserved.
  */
 
+#include <linux/debugfs.h>
 #include <linux/err.h>
 #include <linux/io.h>
 #include <linux/nvmem-consumer.h>
@@ -139,6 +140,77 @@ int get_temp_common(struct tsens_sensor *s, int *temp)
 	return 0;
 }
 
+#ifdef CONFIG_DEBUG_FS
+static int dbg_sensors_show(struct seq_file *s, void *data)
+{
+	struct platform_device *pdev = s->private;
+	struct tsens_priv *priv = platform_get_drvdata(pdev);
+	int i;
+
+	seq_printf(s, "max: %2d\nnum: %2d\n\n",
+		   priv->feat->max_sensors, priv->num_sensors);
+
+	seq_puts(s, "      id    slope   offset\n--------------------------\n");
+	for (i = 0;  i < priv->num_sensors; i++) {
+		seq_printf(s, "%8d %8d %8d\n", priv->sensor[i].hw_id,
+			   priv->sensor[i].slope, priv->sensor[i].offset);
+	}
+
+	return 0;
+}
+
+static int dbg_version_show(struct seq_file *s, void *data)
+{
+	struct platform_device *pdev = s->private;
+	struct tsens_priv *priv = platform_get_drvdata(pdev);
+	u32 maj_ver, min_ver, step_ver;
+	int ret;
+
+	if (tsens_ver(priv) > VER_0_1) {
+		ret = regmap_field_read(priv->rf[VER_MAJOR], &maj_ver);
+		if (ret)
+			return ret;
+		ret = regmap_field_read(priv->rf[VER_MINOR], &min_ver);
+		if (ret)
+			return ret;
+		ret = regmap_field_read(priv->rf[VER_STEP], &step_ver);
+		if (ret)
+			return ret;
+		seq_printf(s, "%d.%d.%d\n", maj_ver, min_ver, step_ver);
+	} else {
+		seq_puts(s, "0.1.0\n");
+	}
+
+	return 0;
+}
+
+DEFINE_SHOW_ATTRIBUTE(dbg_version);
+DEFINE_SHOW_ATTRIBUTE(dbg_sensors);
+
+static void tsens_debug_init(struct platform_device *pdev)
+{
+	struct tsens_priv *priv = platform_get_drvdata(pdev);
+	struct dentry *root, *file;
+
+	root = debugfs_lookup("tsens", NULL);
+	if (!root)
+		priv->debug_root = debugfs_create_dir("tsens", NULL);
+	else
+		priv->debug_root = root;
+
+	file = debugfs_lookup("version", priv->debug_root);
+	if (!file)
+		debugfs_create_file("version", 0444, priv->debug_root,
+				    pdev, &dbg_version_fops);
+
+	/* A directory for each instance of the TSENS IP */
+	priv->debug = debugfs_create_dir(dev_name(&pdev->dev), priv->debug_root);
+	debugfs_create_file("sensors", 0444, priv->debug, pdev, &dbg_sensors_fops);
+}
+#else
+static inline void tsens_debug_init(struct platform_device *pdev) {}
+#endif
+
 static const struct regmap_config tsens_config = {
 	.name		= "tm",
 	.reg_bits	= 32,
@@ -199,6 +271,15 @@ int __init init_common(struct tsens_priv *priv)
 		goto err_put_device;
 	}
 
+	if (tsens_ver(priv) > VER_0_1) {
+		for (i = VER_MAJOR; i <= VER_STEP; i++) {
+			priv->rf[i] = devm_regmap_field_alloc(dev, priv->srot_map,
+							      priv->fields[i]);
+			if (IS_ERR(priv->rf[i]))
+				return PTR_ERR(priv->rf[i]);
+		}
+	}
+
 	priv->rf[TSENS_EN] = devm_regmap_field_alloc(dev, priv->srot_map,
 						     priv->fields[TSENS_EN]);
 	if (IS_ERR(priv->rf[TSENS_EN])) {
@@ -238,6 +319,8 @@ int __init init_common(struct tsens_priv *priv)
 		}
 	}
 
+	tsens_debug_init(op);
+
 	return 0;
 
 err_put_device:

drivers/thermal/qcom/tsens.c

@@ -3,6 +3,7 @@
  * Copyright (c) 2015, The Linux Foundation. All rights reserved.
  */
 
+#include <linux/debugfs.h>
 #include <linux/err.h>
 #include <linux/module.h>
 #include <linux/of.h>
@@ -176,6 +177,7 @@ static int tsens_remove(struct platform_device *pdev)
 {
 	struct tsens_priv *priv = platform_get_drvdata(pdev);
 
+	debugfs_remove_recursive(priv->debug_root);
 	if (priv->ops->disable)
 		priv->ops->disable(priv);
 

drivers/thermal/qcom/tsens.h

@@ -293,6 +293,8 @@ struct tsens_context {
  * @feat: features of the IP
  * @fields: bitfield locations
  * @ops: pointer to list of callbacks supported by this device
+ * @debug_root: pointer to debugfs dentry for all tsens
+ * @debug: pointer to debugfs dentry for tsens controller
  * @sensor: list of sensors attached to this device
  */
 struct tsens_priv {
@@ -306,6 +308,10 @@ struct tsens_priv {
 	const struct tsens_features	*feat;
 	const struct reg_field		*fields;
 	const struct tsens_ops		*ops;
+
+	struct dentry			*debug_root;
+	struct dentry			*debug;
+
 	struct tsens_sensor		sensor[0];
 };