[Skiboot] [PATCH v2 05/13] fsp-sensor: rework device tree for sensors

Cédric Le Goater clg at fr.ibm.com
Sat Feb 21 01:27:28 AEDT 2015


The current code in OPAL exposing the FSP sensors in the device tree
is very SPCN-centric which makes it difficult to add new sensors fitting
with the associated Linux driver. This patch proposes a new layout 
for the device tree to address these issues.

The logic behind the node creation is preserved. The DMA sensor buffer
is parsed, looping on the PRS command modifiers and entries while
nodes are being created under the "ibm,opal/sensors" path. The
code now splits the creation under separate routines, one for each
modifier, and use this new pattern for names :

	<resource class name>@<resource identifier>/

instead of :

	<resource class name>#<index>-attribute/

Currently, we handle the resource classes we know about, that is
"power-supply", "cooling-fan" and "amb-temp". More exist in the specs
but they have not showed up on the Tuleta I used. Each resource node
is compatible with "ibm,opal-sensor".

The way the sensor attributes are exposed also changes. They now all
live together under the resource they are attached to. For example  :

	cooling-fan at 2100/
	   ├── name             "cooling-fan"
	   ├── compatible       "ibm,opal-sensor"
	   ├── ibm,loc-code     "A1"
	   ├── sensor-threshold 01052100 (17113344)
	   ├── sensor-data      02052100 (33890560)
	   ├── phandle          10000016 (268435478)
	   └── linux,phandle    10000016 (268435478)

Each new attribute gets a device node property. Some are constant,
like the location code reported by the SENSOR_PARAM command, others
expose a unique 'sensor handler' which is to be used as an argument
to the OPAL_SENSOR_DATA call to capture the sensor data.

The patch proposes a "data" and a "threshold" attributes for the
supported resource classes. More will be added in subsequent patches.
There is some mapping to be done between the attributes of a same
resource and the PRS command used to collect them. This adds some
complexity in the code when creating the node and when building a
request for the FSP.

Another significant change is that the power consumption is now
reported for each power supply and not as a whole like before. A Tuleta
can have up to four distinct power supplies so it seems an interesting
resource to report independently.

Signed-off-by: Cédric Le Goater <clg at fr.ibm.com>
---
 hw/fsp/fsp-sensor.c |  364 +++++++++++++++++++++++++++++++--------------------
 1 file changed, 224 insertions(+), 140 deletions(-)

diff --git a/hw/fsp/fsp-sensor.c b/hw/fsp/fsp-sensor.c
index 1435e671a3c2..3dab8803dc75 100644
--- a/hw/fsp/fsp-sensor.c
+++ b/hw/fsp/fsp-sensor.c
@@ -230,14 +230,42 @@ static void queue_msg_for_delivery(int rc, struct opal_sensor_data *attr);
  * --------------------------------------------------------------------------
  */
 
+
+/*
+ * When coming from a SENSOR_POWER modifier command, the resource id
+ * of a power supply is on one byte and misses a "subclass" byte
+ * (0x10). This routine adds it to be consistent with the PRS_STATUS
+ * modifier command.
+ */
+#define normalize_power_rid(rid) (0x1000|(rid))
+
+static uint32_t sensor_power_process_data(uint16_t rid,
+					struct sensor_power *power)
+{
+	int i;
+
+	if (!sensor_power_is_valid(power)) {
+		prlog(PR_TRACE, "Power Sensor data not valid\n");
+		return INVALID_DATA;
+	}
+
+	for (i = 0; i < sensor_power_count(power); i++) {
+		prlog(PR_TRACE, "Power[%d]: %d mW\n", i,
+		      power->supplies[i].milliwatts);
+		if (rid == normalize_power_rid(power->supplies[i].rid))
+			return power->supplies[i].milliwatts / 1000;
+	}
+
+	return 0;
+}
+
+
 static void fsp_sensor_process_data(struct opal_sensor_data *attr)
 {
 	uint8_t *sensor_buf_ptr = (uint8_t *)sensor_buffer;
 	uint32_t sensor_data = INVALID_DATA;
 	uint16_t sensor_mod_data[8];
-	int count, i;
-	uint8_t valid, nr_power;
-	uint32_t power;
+	int count;
 
 	for (count = 0; count < spcn_mod_data[attr->mod_index].entry_count;
 			count++) {
@@ -247,19 +275,9 @@ static void fsp_sensor_process_data(struct opal_sensor_data *attr)
 			/* TODO Support this modifier '0x14', if required */
 
 		} else if (spcn_mod_data[attr->mod_index].mod == SPCN_MOD_SENSOR_POWER) {
-			valid = sensor_buf_ptr[0];
-			if (valid & 0x80) {
-				nr_power = valid & 0x0f;
-				sensor_data = 0;
-				for (i=0; i < nr_power; i++) {
-					power = *(uint32_t *) &sensor_buf_ptr[2 + i * 5];
-					prlog(PR_TRACE, "Power[%d]: %d mW\n",
-					      i, power);
-					sensor_data += power/1000;
-				}
-			} else {
-				prlog(PR_TRACE, "Power Sensor data not valid\n");
-			}
+			sensor_data = sensor_power_process_data(attr->rid,
+					(struct sensor_power *) sensor_buf_ptr);
+			break;
 		} else if (sensor_mod_data[0] == attr->frc &&
 				sensor_mod_data[1] == attr->rid) {
 			switch (attr->spcn_attr) {
@@ -413,7 +431,7 @@ static int64_t fsp_sensor_send_read_request(struct opal_sensor_data *attr)
 	uint32_t align;
 	uint32_t cmd_header;
 
-	prlog(PR_INSANE, "Get the data for modifier [%d]\n",
+	prlog(PR_INSANE, "Get the data for modifier [%x]\n",
 	      spcn_mod_data[attr->mod_index].mod);
 
 	if (spcn_mod_data[attr->mod_index].mod == SPCN_MOD_PROC_JUNC_TEMP) {
@@ -459,24 +477,66 @@ static int64_t fsp_sensor_send_read_request(struct opal_sensor_data *attr)
 	return OPAL_ASYNC_COMPLETION;
 }
 
-static int64_t parse_sensor_id(uint32_t id, struct opal_sensor_data *attr)
+/*
+ * These are the resources we know about and for which we provide a
+ * mapping in the device tree to capture data from the OS. Just
+ * discard the other ones for the moment.
+ */
+static inline bool sensor_frc_is_valid(uint16_t frc)
+{
+	switch (frc) {
+	case SENSOR_FRC_POWER_SUPPLY:
+	case SENSOR_FRC_COOLING_FAN:
+	case SENSOR_FRC_AMB_TEMP:
+		return true;
+	default:
+		return false;
+	}
+}
+
+/*
+ * Each attribute of a resource needs a request to the FSP to capture
+ * its data. The routine below provides the mapping between the
+ * attribute and the PRS command modifier to use.
+ *
+ *	resource        | data   |  thrs  |
+ *	----------------+--------+--------+
+ *	power_supply    | POWER  |        |
+ *	----------------+--------+--------+
+ *	amb-temp        | DATA   |        |
+ *	                |        | PARAM  |
+ *	----------------+--------+--------+
+ *	fan             | DATA   |        |
+ *	                |        | PARAM  |
+ *	                |        |        |
+ */
+static int64_t parse_sensor_id(uint32_t handler, struct opal_sensor_data *attr)
 {
 	uint32_t mod, index;
 
-	attr->spcn_attr = id >> 24;
-	if (attr->spcn_attr >= SENSOR_MAX)
+	attr->frc = sensor_get_frc(handler);
+	attr->rid = sensor_get_rid(handler);
+	attr->spcn_attr = sensor_get_attr(handler);
+
+	if (!sensor_frc_is_valid(attr->frc))
 		return OPAL_PARAMETER;
 
-	if (attr->spcn_attr <= SENSOR_ON_SUPPORTED)
-		mod = SPCN_MOD_PRS_STATUS_FIRST;
-	else if (attr->spcn_attr <= SENSOR_LOCATION)
+	/* now compute the PRS command modifier which will be used to
+	 * request a resource attribute from the FSP */
+	switch (attr->spcn_attr) {
+	case SENSOR_DATA:
+		if (attr->frc == SENSOR_FRC_POWER_SUPPLY)
+			mod = SPCN_MOD_SENSOR_POWER;
+		else
+			mod = SPCN_MOD_SENSOR_DATA_FIRST;
+		break;
+
+	case SENSOR_THRS:
 		mod = SPCN_MOD_SENSOR_PARAM_FIRST;
-	else if (attr->spcn_attr <= SENSOR_DATA)
-		mod = SPCN_MOD_SENSOR_DATA_FIRST;
-	else if (attr->spcn_attr <= SENSOR_POWER)
-		mod = SPCN_MOD_SENSOR_POWER;
-	else
+		break;
+	default:
 		return OPAL_PARAMETER;
+	}
 
 	for (index = 0; spcn_mod_data[index].mod != SPCN_MOD_LAST; index++) {
 		if (spcn_mod_data[index].mod == mod)
@@ -484,9 +544,6 @@ static int64_t parse_sensor_id(uint32_t id, struct opal_sensor_data *attr)
 	}
 
 	attr->mod_index = index;
-	attr->frc = (id >> 16) & 0xff;
-	attr->rid = id & 0xffff;
-
 	return 0;
 }
 
@@ -555,138 +612,165 @@ out:
 	return rc;
 }
 
-
-#define MAX_RIDS	64
 #define MAX_NAME	64
 
-static int get_index(uint16_t *prids, uint16_t rid)
+static struct dt_node *sensor_get_node(struct dt_node *sensors,
+				struct sensor_header *header)
 {
-	int index;
+	char name[MAX_NAME];
+	struct dt_node *node;
+
+	/*
+	 * Just use the resource class name and resource id. This
+	 * should be obvious enough for a node name.
+	 */
+	snprintf(name, sizeof(name), "%s@%x", frc_names[header->frc],
+		 header->rid);
+
+	/*
+	 * The same resources are reported by the different PRS
+	 * subcommands (PRS_STATUS, SENSOR_PARAM, SENSOR_DATA). So we
+	 * need to check that we did not already create the device
+	 * node.
+	 */
+	node = dt_find_by_path(sensors, name);
+	if (!node) {
+		prlog(PR_TRACE, "SENSOR: creating node %s\n", name);
+
+		node = dt_new(sensors, name);
+
+		dt_add_property_string(node, "compatible", "ibm,opal-sensor");
+	}
+	return node;
+}
+
+#define sensor_handler(header, attr_num) \
+	sensor_make_handler((header).frc, (header).rid, attr_num)
 
-	for (index = 0; prids[index] && index < MAX_RIDS; index++)
-		if (prids[index] == rid)
-			return index;
+static int add_sensor_prs(struct dt_node *sensors, struct sensor_prs *prs)
+{
+	struct dt_node *node;
 
-	if (index == MAX_RIDS)
+	node = sensor_get_node(sensors, &prs->header);
+	if (!node)
 		return -1;
 
-	prids[index] = rid;
-	return index;
+	return 0;
 }
 
-static void create_sensor_nodes(int index, uint16_t frc, uint16_t rid,
-		uint16_t *prids, struct dt_node *sensors)
+static int add_sensor_param(struct dt_node *sensors, struct sensor_param *param)
 {
-	char name[MAX_NAME];
-	struct dt_node *fs_node;
-	uint32_t value;
-	int rid_index;
-
-	switch (spcn_mod_data[index].mod) {
-	case SPCN_MOD_PRS_STATUS_FIRST:
-	case SPCN_MOD_PRS_STATUS_SUBS:
-		switch (frc) {
-		case SENSOR_FRC_POWER_SUPPLY:
-		case SENSOR_FRC_COOLING_FAN:
-			rid_index = get_index(prids, rid);
-			if (rid_index < 0)
-				break;
-			snprintf(name, MAX_NAME, "%s#%d-%s", frc_names[frc],
-					/* Start enumeration from 1 */
-					rid_index + 1,
-					spcn_mod_data[index].mod_attr[1].name);
-			fs_node = dt_new(sensors, name);
-			snprintf(name, MAX_NAME, "ibm,opal-sensor-%s",
-					frc_names[frc]);
-			dt_add_property_string(fs_node, "compatible", name);
-			value = spcn_mod_data[index].mod_attr[1].val << 24 |
-					(frc & 0xff) << 16 | rid;
-			dt_add_property_cells(fs_node, "sensor-id", value);
-			break;
-		default:
-			break;
-		}
-		break;
-	case SPCN_MOD_SENSOR_PARAM_FIRST:
-	case SPCN_MOD_SENSOR_PARAM_SUBS:
-	case SPCN_MOD_SENSOR_DATA_FIRST:
-	case SPCN_MOD_SENSOR_DATA_SUBS:
-		switch (frc) {
-		case SENSOR_FRC_POWER_SUPPLY:
-		case SENSOR_FRC_COOLING_FAN:
-		case SENSOR_FRC_AMB_TEMP:
-			rid_index = get_index(prids, rid);
-			if (rid_index < 0)
-				break;
-			snprintf(name, MAX_NAME, "%s#%d-%s", frc_names[frc],
-					/* Start enumeration from 1 */
-					rid_index + 1,
-					spcn_mod_data[index].mod_attr[0].name);
-			fs_node = dt_new(sensors, name);
-			snprintf(name, MAX_NAME, "ibm,opal-sensor-%s",
-					frc_names[frc]);
-			dt_add_property_string(fs_node, "compatible", name);
-			value = spcn_mod_data[index].mod_attr[0].val << 24 |
-					(frc & 0xff) << 16 | rid;
-			dt_add_property_cells(fs_node, "sensor-id", value);
-			break;
-		default:
-			break;
-		}
-		break;
+	struct dt_node *node;
 
-	case SPCN_MOD_SENSOR_POWER:
-		fs_node = dt_new(sensors, "power#1-data");
-		dt_add_property_string(fs_node, "compatible", "ibm,opal-sensor-power");
-		value = spcn_mod_data[index].mod_attr[0].val << 24;
-		dt_add_property_cells(fs_node, "sensor-id", value);
-		break;
+	node = sensor_get_node(sensors, &param->header);
+	if (!node)
+		return -1;
+
+	dt_add_property_string(node, "ibm,loc-code", param->location);
+	dt_add_property_cells(node, "sensor-threshold",
+			      sensor_handler(param->header, SENSOR_THRS));
+	return 0;
+}
+
+static int add_sensor_data(struct dt_node *sensors,
+				struct sensor_data *data)
+{
+	struct dt_node *node;
+
+	node = sensor_get_node(sensors, &data->header);
+	if (!node)
+		return -1;
+
+	dt_add_property_cells(node, "sensor-data",
+			      sensor_handler(data->header, SENSOR_DATA));
+	return 0;
+}
+
+static int add_sensor_power(struct dt_node *sensors, struct sensor_power *power)
+{
+	int i;
+	struct dt_node *node;
+
+	if (!sensor_power_is_valid(power))
+		return -1;
+
+	for (i = 0; i < sensor_power_count(power); i++) {
+		struct sensor_header header = {
+			SENSOR_FRC_POWER_SUPPLY,
+			normalize_power_rid(power->supplies[i].rid)
+		};
+
+		node = sensor_get_node(sensors, &header);
+
+		prlog(PR_TRACE, "SENSOR: Power[%d] : %d mW\n",
+		      power->supplies[i].rid,
+		      power->supplies[i].milliwatts);
+
+		dt_add_property_cells(node, "sensor-data",
+				      sensor_handler(header, SENSOR_DATA));
 	}
+	return 0;
 }
 
 static void add_sensor_ids(struct dt_node *sensors)
 {
-	uint32_t MAX_FRC_NAMES = sizeof(frc_names) / sizeof(*frc_names);
 	uint8_t *sensor_buf_ptr = (uint8_t *)sensor_buffer;
-	uint16_t *prids[MAX_FRC_NAMES];
-	uint16_t sensor_frc, power_rid;
-	uint16_t sensor_mod_data[8];
-	uint32_t index, count;
-
-	for (index = 0; index < MAX_FRC_NAMES; index++)
-		prids[index] = zalloc(MAX_RIDS * sizeof(**prids));
-
-	for (index = 0; spcn_mod_data[index].mod != SPCN_MOD_LAST; index++) {
-		if (spcn_mod_data[index].mod == SPCN_MOD_SENSOR_POWER) {
-			create_sensor_nodes(index, 0, 0, 0, sensors);
+	struct spcn_mod *smod;
+	int i;
+
+	for (smod = spcn_mod_data; smod->mod != SPCN_MOD_LAST; smod++) {
+		/*
+		 * SPCN_MOD_SENSOR_POWER (0x1C) has a different layout.
+		 */
+		if (smod->mod == SPCN_MOD_SENSOR_POWER) {
+			add_sensor_power(sensors,
+				      (struct sensor_power *) sensor_buf_ptr);
+
+			sensor_buf_ptr += smod->entry_size * smod->entry_count;
 			continue;
 		}
-		for (count = 0; count < spcn_mod_data[index].entry_count;
-				count++) {
-			if (spcn_mod_data[index].mod ==
-					SPCN_MOD_PROC_JUNC_TEMP) {
-				/* TODO Support this modifier '0x14', if
-				 * required */
-			} else {
-				memcpy((void *)sensor_mod_data, sensor_buf_ptr,
-						spcn_mod_data[index].entry_size);
-				sensor_frc = sensor_mod_data[0];
-				power_rid = sensor_mod_data[1];
-
-				if (sensor_frc < MAX_FRC_NAMES &&
-						frc_names[sensor_frc])
-					create_sensor_nodes(index, sensor_frc,
-							power_rid,
-							prids[sensor_frc],
-							sensors);
+
+		for (i = 0; i < smod->entry_count; i++) {
+			struct sensor_header *header =
+				(struct sensor_header *) sensor_buf_ptr;
+
+			if (!sensor_frc_is_valid(header->frc))
+				goto out_sensor;
+
+			switch (smod->mod) {
+			case SPCN_MOD_PROC_JUNC_TEMP:
+				/* TODO Support this modifier '0x14',
+				   if required */
+				break;
+
+			case SPCN_MOD_PRS_STATUS_FIRST:
+			case SPCN_MOD_PRS_STATUS_SUBS:
+				add_sensor_prs(sensors,
+					(struct sensor_prs *) header);
+				break;
+
+			case SPCN_MOD_SENSOR_PARAM_FIRST:
+			case SPCN_MOD_SENSOR_PARAM_SUBS:
+				add_sensor_param(sensors,
+					(struct sensor_param *) header);
+				break;
+
+			case SPCN_MOD_SENSOR_DATA_FIRST:
+			case SPCN_MOD_SENSOR_DATA_SUBS:
+				add_sensor_data(sensors,
+					(struct sensor_data *) header);
+
+				break;
+
+			default:
+				prerror("SENSOR: unknown modifier : %x\n",
+					smod->mod);
 			}
 
-			sensor_buf_ptr += spcn_mod_data[index].entry_size;
+out_sensor:
+			sensor_buf_ptr += smod->entry_size;
 		}
 	}
-
-	for (index = 0; index < MAX_FRC_NAMES; index++)
-		free(prids[index]);
 }
 
 static void add_opal_sensor_node(void)
-- 
1.7.10.4



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