coresight: cti: Add connection information to sysfs

Dynamically adds sysfs attributes for all connections defined in the CTI.

Each connection has a triggers<N> sub-directory with name, in_signals,
in_types, out_signals and out_types as read-only parameters in the
directory. in_ or out_ parameters may be omitted if there are no in or
out signals for the connection.

Additionally each device has a nr_cons in the connections sub-directory.

This allows clients to explore the connection and trigger signal details
without needing to refer to device tree or specification of the device.

Standardised type information is provided for certain common functions -
e.g. snk_full for a trigger from a sink indicating full. Otherwise type
defaults to genio.
Signed-off-by: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20200320165303.13681-10-mathieu.poirier@linaro.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/hwtracing/coresight/coresight-cti-sysfs.c

@@ -8,6 +8,67 @@
 
 #include "coresight-cti.h"
 
+/*
+ * Declare the number of static declared attribute groups
+ * Value includes groups + NULL value at end of table.
+ */
+#define CORESIGHT_CTI_STATIC_GROUPS_MAX 5
+
+/*
+ * List of trigger signal type names. Match the constants declared in
+ * include\dt-bindings\arm\coresight-cti-dt.h
+ */
+static const char * const sig_type_names[] = {
+	"genio",	/* GEN_IO */
+	"intreq",	/* GEN_INTREQ */
+	"intack",	/* GEN_INTACK */
+	"haltreq",	/* GEN_HALTREQ */
+	"restartreq",	/* GEN_RESTARTREQ */
+	"pe_edbgreq",	/* PE_EDBGREQ */
+	"pe_dbgrestart",/* PE_DBGRESTART */
+	"pe_ctiirq",	/* PE_CTIIRQ */
+	"pe_pmuirq",	/* PE_PMUIRQ */
+	"pe_dbgtrigger",/* PE_DBGTRIGGER */
+	"etm_extout",	/* ETM_EXTOUT */
+	"etm_extin",	/* ETM_EXTIN */
+	"snk_full",	/* SNK_FULL */
+	"snk_acqcomp",	/* SNK_ACQCOMP */
+	"snk_flushcomp",/* SNK_FLUSHCOMP */
+	"snk_flushin",	/* SNK_FLUSHIN */
+	"snk_trigin",	/* SNK_TRIGIN */
+	"stm_asyncout",	/* STM_ASYNCOUT */
+	"stm_tout_spte",/* STM_TOUT_SPTE */
+	"stm_tout_sw",	/* STM_TOUT_SW */
+	"stm_tout_hete",/* STM_TOUT_HETE */
+	"stm_hwevent",	/* STM_HWEVENT */
+	"ela_tstart",	/* ELA_TSTART */
+	"ela_tstop",	/* ELA_TSTOP */
+	"ela_dbgreq",	/* ELA_DBGREQ */
+};
+
+/* Show function pointer used in the connections dynamic declared attributes*/
+typedef ssize_t (*p_show_fn)(struct device *dev, struct device_attribute *attr,
+			     char *buf);
+
+/* Connection attribute types */
+enum cti_conn_attr_type {
+	CTI_CON_ATTR_NAME,
+	CTI_CON_ATTR_TRIGIN_SIG,
+	CTI_CON_ATTR_TRIGOUT_SIG,
+	CTI_CON_ATTR_TRIGIN_TYPES,
+	CTI_CON_ATTR_TRIGOUT_TYPES,
+	CTI_CON_ATTR_MAX,
+};
+
+/* Names for the connection attributes */
+static const char * const con_attr_names[CTI_CON_ATTR_MAX] = {
+	"name",
+	"in_signals",
+	"out_signals",
+	"in_types",
+	"out_types",
+};
+
 /* basic attributes */
 static ssize_t enable_show(struct device *dev,
 			   struct device_attribute *attr,
@@ -75,11 +136,22 @@ static ssize_t ctmid_show(struct device *dev,
 }
 static DEVICE_ATTR_RO(ctmid);
 
+static ssize_t nr_trigger_cons_show(struct device *dev,
+				    struct device_attribute *attr,
+				    char *buf)
+{
+	struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
+
+	return sprintf(buf, "%d\n", drvdata->ctidev.nr_trig_con);
+}
+static DEVICE_ATTR_RO(nr_trigger_cons);
+
 /* attribute and group sysfs tables. */
 static struct attribute *coresight_cti_attrs[] = {
 	&dev_attr_enable.attr,
 	&dev_attr_powered.attr,
 	&dev_attr_ctmid.attr,
+	&dev_attr_nr_trigger_cons.attr,
 	NULL,
 };
 
@@ -850,7 +922,261 @@ static struct attribute *coresight_cti_channel_attrs[] = {
 	NULL,
 };
 
-/* sysfs groups */
+/* Create the connections trigger groups and attrs dynamically */
+/*
+ * Each connection has dynamic group triggers<N> + name, trigin/out sigs/types
+ * attributes, + each device has static nr_trigger_cons giving the number
+ * of groups. e.g. in sysfs:-
+ * /cti_<name>/triggers0
+ * /cti_<name>/triggers1
+ * /cti_<name>/nr_trigger_cons
+ * where nr_trigger_cons = 2
+ */
+static ssize_t con_name_show(struct device *dev,
+			     struct device_attribute *attr,
+			     char *buf)
+{
+	struct dev_ext_attribute *ext_attr =
+		container_of(attr, struct dev_ext_attribute, attr);
+	struct cti_trig_con *con = (struct cti_trig_con *)ext_attr->var;
+
+	return sprintf(buf, "%s\n", con->con_dev_name);
+}
+
+static ssize_t trigin_sig_show(struct device *dev,
+			       struct device_attribute *attr,
+			       char *buf)
+{
+	struct dev_ext_attribute *ext_attr =
+		container_of(attr, struct dev_ext_attribute, attr);
+	struct cti_trig_con *con = (struct cti_trig_con *)ext_attr->var;
+	struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	struct cti_config *cfg = &drvdata->config;
+	unsigned long mask = con->con_in->used_mask;
+
+	return bitmap_print_to_pagebuf(true, buf, &mask, cfg->nr_trig_max);
+}
+
+static ssize_t trigout_sig_show(struct device *dev,
+				struct device_attribute *attr,
+				char *buf)
+{
+	struct dev_ext_attribute *ext_attr =
+		container_of(attr, struct dev_ext_attribute, attr);
+	struct cti_trig_con *con = (struct cti_trig_con *)ext_attr->var;
+	struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	struct cti_config *cfg = &drvdata->config;
+	unsigned long mask = con->con_out->used_mask;
+
+	return bitmap_print_to_pagebuf(true, buf, &mask, cfg->nr_trig_max);
+}
+
+/* convert a sig type id to a name */
+static const char *
+cti_sig_type_name(struct cti_trig_con *con, int used_count, bool in)
+{
+	int idx = 0;
+	struct cti_trig_grp *grp = in ? con->con_in : con->con_out;
+
+	if (used_count < grp->nr_sigs)
+		idx = grp->sig_types[used_count];
+	return sig_type_names[idx];
+}
+
+static ssize_t trigin_type_show(struct device *dev,
+				struct device_attribute *attr,
+				char *buf)
+{
+	struct dev_ext_attribute *ext_attr =
+		container_of(attr, struct dev_ext_attribute, attr);
+	struct cti_trig_con *con = (struct cti_trig_con *)ext_attr->var;
+	int sig_idx, used = 0;
+	const char *name;
+
+	for (sig_idx = 0; sig_idx < con->con_in->nr_sigs; sig_idx++) {
+		name = cti_sig_type_name(con, sig_idx, true);
+		used += sprintf(buf + used, "%s ", name);
+	}
+	used += sprintf(buf + used, "\n");
+	return used;
+}
+
+static ssize_t trigout_type_show(struct device *dev,
+				 struct device_attribute *attr,
+				 char *buf)
+{
+	struct dev_ext_attribute *ext_attr =
+		container_of(attr, struct dev_ext_attribute, attr);
+	struct cti_trig_con *con = (struct cti_trig_con *)ext_attr->var;
+	int sig_idx, used = 0;
+	const char *name;
+
+	for (sig_idx = 0; sig_idx < con->con_out->nr_sigs; sig_idx++) {
+		name = cti_sig_type_name(con, sig_idx, false);
+		used += sprintf(buf + used, "%s ", name);
+	}
+	used += sprintf(buf + used, "\n");
+	return used;
+}
+
+/*
+ * Array of show function names declared above to allow selection
+ * for the connection attributes
+ */
+static p_show_fn show_fns[CTI_CON_ATTR_MAX] = {
+	con_name_show,
+	trigin_sig_show,
+	trigout_sig_show,
+	trigin_type_show,
+	trigout_type_show,
+};
+
+static int cti_create_con_sysfs_attr(struct device *dev,
+				     struct cti_trig_con *con,
+				     enum cti_conn_attr_type attr_type,
+				     int attr_idx)
+{
+	struct dev_ext_attribute *eattr = 0;
+	char *name = 0;
+
+	eattr = devm_kzalloc(dev, sizeof(struct dev_ext_attribute),
+				    GFP_KERNEL);
+	if (eattr) {
+		name = devm_kstrdup(dev, con_attr_names[attr_type],
+				    GFP_KERNEL);
+		if (name) {
+			/* fill out the underlying attribute struct */
+			eattr->attr.attr.name = name;
+			eattr->attr.attr.mode = 0444;
+
+			/* now the device_attribute struct */
+			eattr->attr.show = show_fns[attr_type];
+		} else {
+			return -ENOMEM;
+		}
+	} else {
+		return -ENOMEM;
+	}
+	eattr->var = con;
+	con->con_attrs[attr_idx] = &eattr->attr.attr;
+	return 0;
+}
+
+static struct attribute_group *
+cti_create_con_sysfs_group(struct device *dev, struct cti_device *ctidev,
+			   int con_idx, struct cti_trig_con *tc)
+{
+	struct attribute_group *group = NULL;
+	int grp_idx;
+
+	group = devm_kzalloc(dev, sizeof(struct attribute_group), GFP_KERNEL);
+	if (!group)
+		return NULL;
+
+	group->name = devm_kasprintf(dev, GFP_KERNEL, "triggers%d", con_idx);
+	if (!group->name)
+		return NULL;
+
+	grp_idx = con_idx + CORESIGHT_CTI_STATIC_GROUPS_MAX - 1;
+	ctidev->con_groups[grp_idx] = group;
+	tc->attr_group = group;
+	return group;
+}
+
+/* create a triggers connection group and the attributes for that group */
+static int cti_create_con_attr_set(struct device *dev, int con_idx,
+				   struct cti_device *ctidev,
+				   struct cti_trig_con *tc)
+{
+	struct attribute_group *attr_group = NULL;
+	int attr_idx = 0;
+	int err = -ENOMEM;
+
+	attr_group = cti_create_con_sysfs_group(dev, ctidev, con_idx, tc);
+	if (!attr_group)
+		return -ENOMEM;
+
+	/* allocate NULL terminated array of attributes */
+	tc->con_attrs = devm_kcalloc(dev, CTI_CON_ATTR_MAX + 1,
+				     sizeof(struct attribute *), GFP_KERNEL);
+	if (!tc->con_attrs)
+		return -ENOMEM;
+
+	err = cti_create_con_sysfs_attr(dev, tc, CTI_CON_ATTR_NAME,
+					attr_idx++);
+	if (err)
+		return err;
+
+	if (tc->con_in->nr_sigs > 0) {
+		err = cti_create_con_sysfs_attr(dev, tc,
+						CTI_CON_ATTR_TRIGIN_SIG,
+						attr_idx++);
+		if (err)
+			return err;
+
+		err = cti_create_con_sysfs_attr(dev, tc,
+						CTI_CON_ATTR_TRIGIN_TYPES,
+						attr_idx++);
+		if (err)
+			return err;
+	}
+
+	if (tc->con_out->nr_sigs > 0) {
+		err = cti_create_con_sysfs_attr(dev, tc,
+						CTI_CON_ATTR_TRIGOUT_SIG,
+						attr_idx++);
+		if (err)
+			return err;
+
+		err = cti_create_con_sysfs_attr(dev, tc,
+						CTI_CON_ATTR_TRIGOUT_TYPES,
+						attr_idx++);
+		if (err)
+			return err;
+	}
+	attr_group->attrs = tc->con_attrs;
+	return 0;
+}
+
+/* create the array of group pointers for the CTI sysfs groups */
+int cti_create_cons_groups(struct device *dev, struct cti_device *ctidev)
+{
+	int nr_groups;
+
+	/* nr groups = dynamic + static + NULL terminator */
+	nr_groups = ctidev->nr_trig_con + CORESIGHT_CTI_STATIC_GROUPS_MAX;
+	ctidev->con_groups = devm_kcalloc(dev, nr_groups,
+					  sizeof(struct attribute_group *),
+					  GFP_KERNEL);
+	if (!ctidev->con_groups)
+		return -ENOMEM;
+	return 0;
+}
+
+int cti_create_cons_sysfs(struct device *dev, struct cti_drvdata *drvdata)
+{
+	struct cti_device *ctidev = &drvdata->ctidev;
+	int err = 0, con_idx = 0, i;
+	struct cti_trig_con *tc = NULL;
+
+	err = cti_create_cons_groups(dev, ctidev);
+	if (err)
+		return err;
+
+	/* populate first locations with the static set of groups */
+	for (i = 0; i < (CORESIGHT_CTI_STATIC_GROUPS_MAX - 1); i++)
+		ctidev->con_groups[i] = coresight_cti_groups[i];
+
+	/* add dynamic set for each connection */
+	list_for_each_entry(tc, &ctidev->trig_cons, node) {
+		err = cti_create_con_attr_set(dev, con_idx++, ctidev, tc);
+		if (err)
+			break;
+	}
+	return err;
+}
+
+/* attribute and group sysfs tables. */
 static const struct attribute_group coresight_cti_group = {
 	.attrs = coresight_cti_attrs,
 };
@@ -870,7 +1196,8 @@ static const struct attribute_group coresight_cti_channels_group = {
 	.name = "channels",
 };
 
-const struct attribute_group *coresight_cti_groups[] = {
+const struct attribute_group *
+coresight_cti_groups[CORESIGHT_CTI_STATIC_GROUPS_MAX] = {
 	&coresight_cti_group,
 	&coresight_cti_mgmt_group,
 	&coresight_cti_regs_group,

drivers/hwtracing/coresight/coresight-cti.c

@@ -673,12 +673,20 @@ static int cti_probe(struct amba_device *adev, const struct amba_id *id)
 		goto err_out;
 	}
 
+	/* create dynamic attributes for connections */
+	ret = cti_create_cons_sysfs(dev, drvdata);
+	if (ret) {
+		dev_err(dev, "%s: create dynamic sysfs entries failed\n",
+			cti_desc.name);
+		goto err_out;
+	}
+
 	/* set up coresight component description */
 	cti_desc.pdata = pdata;
 	cti_desc.type = CORESIGHT_DEV_TYPE_ECT;
 	cti_desc.subtype.ect_subtype = CORESIGHT_DEV_SUBTYPE_ECT_CTI;
 	cti_desc.ops = &cti_ops;
-	cti_desc.groups = coresight_cti_groups;
+	cti_desc.groups = drvdata->ctidev.con_groups;
 	cti_desc.dev = dev;
 	drvdata->csdev = coresight_register(&cti_desc);
 	if (IS_ERR(drvdata->csdev)) {

drivers/hwtracing/coresight/coresight-cti.h

@@ -74,6 +74,8 @@ struct cti_trig_grp {
  * @con_dev: coresight device connected to the CTI, NULL if not CS device
  * @con_dev_name: name of connected device (CS or CPU)
  * @node: entry node in list of connections.
+ * @con_attrs: Dynamic sysfs attributes specific to this connection.
+ * @attr_group: Dynamic attribute group created for this connection.
  */
 struct cti_trig_con {
 	struct cti_trig_grp *con_in;
@@ -81,6 +83,8 @@ struct cti_trig_con {
 	struct coresight_device *con_dev;
 	const char *con_dev_name;
 	struct list_head node;
+	struct attribute **con_attrs;
+	struct attribute_group *attr_group;
 };
 
 /**
@@ -91,12 +95,15 @@ struct cti_trig_con {
  *          assumed there is a single CTM per SoC, ID 0).
  * @trig_cons: list of connections to this device.
  * @cpu: CPU ID if associated with CPU, -1 otherwise.
+ * @con_groups: combined static and dynamic sysfs groups for trigger
+ *		connections.
  */
 struct cti_device {
 	int nr_trig_con;
 	u32 ctm_id;
 	struct list_head trig_cons;
 	int cpu;
+	const struct attribute_group **con_groups;
 };
 
 /**
@@ -214,6 +221,7 @@ int cti_channel_gate_op(struct device *dev, enum cti_chan_gate_op op,
 			u32 channel_idx);
 int cti_channel_setop(struct device *dev, enum cti_chan_set_op op,
 		      u32 channel_idx);
+int cti_create_cons_sysfs(struct device *dev, struct cti_drvdata *drvdata);
 struct coresight_platform_data *
 coresight_cti_get_platform_data(struct device *dev);
 const char *cti_plat_get_node_name(struct fwnode_handle *fwnode);