Implement support for SR_CONF_PROBE_FACTOR setting in BayLibre ACME
driver. Given the channel-group parameter this allows to set the
shunt resistance for each probe.
Signed-off-by: Bartosz Golaszewski <bgolaszew...@baylibre.com>
---
src/hardware/baylibre-acme/api.c | 18 ++++--
src/hardware/baylibre-acme/protocol.c | 108 ++++++++++++++++++++++++++++++++++
src/hardware/baylibre-acme/protocol.h | 5 ++
3 files changed, 127 insertions(+), 4 deletions(-)
diff --git a/src/hardware/baylibre-acme/api.c b/src/hardware/baylibre-acme/api.c
index 89d8b09..201f934 100644
--- a/src/hardware/baylibre-acme/api.c
+++ b/src/hardware/baylibre-acme/api.c
@@ -27,6 +27,7 @@ static const uint32_t devopts[] = {
SR_CONF_LIMIT_SAMPLES | SR_CONF_GET | SR_CONF_SET,
SR_CONF_LIMIT_MSEC | SR_CONF_GET | SR_CONF_SET,
SR_CONF_SAMPLERATE | SR_CONF_GET | SR_CONF_SET | SR_CONF_LIST,
+ SR_CONF_PROBE_FACTOR | SR_CONF_GET | SR_CONF_SET,
};
#define MAX_SAMPLE_RATE 500 /* In Hz */
@@ -168,8 +169,7 @@ static int config_get(uint32_t key, GVariant **data,
{
struct dev_context *devc;
int ret;
-
- (void)cg;
+ uint64_t shunt;
devc = sdi->priv;
@@ -184,6 +184,13 @@ static int config_get(uint32_t key, GVariant **data,
case SR_CONF_SAMPLERATE:
*data = g_variant_new_uint64(devc->samplerate);
break;
+ case SR_CONF_PROBE_FACTOR:
+ if (!cg)
+ return SR_ERR_CHANNEL_GROUP;
+ ret = bl_acme_get_shunt(cg, &shunt);
+ if (ret == SR_OK)
+ *data = g_variant_new_uint64(shunt);
+ break;
default:
return SR_ERR_NA;
}
@@ -199,8 +206,6 @@ static int config_set(uint32_t key, GVariant *data,
uint64_t samplerate;
int ret;
- (void)cg;
-
if (sdi->status != SR_ST_ACTIVE)
return SR_ERR_DEV_CLOSED;
@@ -229,6 +234,11 @@ static int config_set(uint32_t key, GVariant *data,
devc->samplerate = samplerate;
sr_dbg("Setting samplerate to %" PRIu64, devc->samplerate);
break;
+ case SR_CONF_PROBE_FACTOR:
+ if (!cg)
+ return SR_ERR_CHANNEL_GROUP;
+ ret = bl_acme_set_shunt(cg, g_variant_get_uint64(data));
+ break;
default:
ret = SR_ERR_NA;
}
diff --git a/src/hardware/baylibre-acme/protocol.c
b/src/hardware/baylibre-acme/protocol.c
index 272a4ff..22af9f9 100644
--- a/src/hardware/baylibre-acme/protocol.c
+++ b/src/hardware/baylibre-acme/protocol.c
@@ -21,10 +21,12 @@
#include <stdlib.h> /* strtol() */
#include <errno.h>
#include <fcntl.h> /* open(), etc... */
+#include <glib/gstdio.h>
#include "protocol.h"
struct channel_group_priv {
int hwmon_num;
+ int probe_type;
};
struct channel_priv {
@@ -40,6 +42,9 @@ static const uint8_t temp_i2c_addrs[] = {
0x0, 0x0, 0x0, 0x0, 0x4c, 0x49, 0x4f, 0x4b,
};
+#define MOHM_TO_UOHM(x) ((x) * 1000)
+#define UOHM_TO_MOHM(x) ((x) / 1000)
+
SR_PRIV uint8_t bl_acme_get_enrg_addr(int index)
{
return enrg_i2c_addrs[index];
@@ -212,6 +217,7 @@ SR_PRIV gboolean bl_acme_register_probe(struct sr_dev_inst
*sdi, int type,
cg = g_malloc0(sizeof(struct sr_channel_group));
cgp = g_malloc0(sizeof(struct channel_group_priv));
cgp->hwmon_num = hwmon;
+ cgp->probe_type = type;
cg->name = g_strdup_printf("Probe_%d", prb_num);
cg->priv = cgp;
@@ -231,6 +237,108 @@ SR_PRIV gboolean bl_acme_register_probe(struct
sr_dev_inst *sdi, int type,
return TRUE;
}
+/*
+ * Sets path to the hwmon attribute if this channel group
+ * supports shunt resistance setting. The caller has to supply
+ * a valid GString.
+ */
+static int get_shunt_path(const struct sr_channel_group *cg, GString *path)
+{
+ struct channel_group_priv *cgp;
+ int ret = SR_OK, status;
+
+ cgp = cg->priv;
+
+ if (cgp->probe_type != PROBE_ENRG) {
+ sr_err("Probe doesn't support shunt resistance setting");
+ return SR_ERR_ARG;
+ }
+
+ g_string_append_printf(path,
+ "/sys/class/hwmon/hwmon%d/shunt_resistor",
+ cgp->hwmon_num);
+
+ /*
+ * The shunt_resistor sysfs attribute is available
+ * in the Linux kernel since version 3.20. We have
+ * to notify the user if this attribute is not
+ * present.
+ */
+ status = g_file_test(path->str, G_FILE_TEST_EXISTS);
+ if (!status) {
+ sr_err("shunt_resistance attribute not present please update "
+ "your kernel to version >=3.20");
+ return SR_ERR_NA;
+ }
+
+ return ret;
+}
+
+SR_PRIV int bl_acme_get_shunt(const struct sr_channel_group *cg,
+ uint64_t *shunt)
+{
+ GString *path = g_string_sized_new(64);
+ gchar *contents;
+ int status, ret = SR_OK;
+ GError *err = NULL;
+
+ status = get_shunt_path(cg, path);
+ if (status != SR_OK) {
+ ret = status;
+ goto out;
+ }
+
+ status = g_file_get_contents(path->str, &contents, NULL, &err);
+ if (!status) {
+ sr_err("Error reading shunt resistance: %s", err->message);
+ ret = SR_ERR_IO;
+ goto out;
+ }
+
+ *shunt = UOHM_TO_MOHM(strtol(contents, NULL, 10));
+
+out:
+ g_string_free(path, TRUE);
+ return ret;
+}
+
+SR_PRIV int bl_acme_set_shunt(const struct sr_channel_group *cg,
+ uint64_t shunt)
+{
+ GString *path = g_string_sized_new(64);;
+ int status, ret = SR_OK;
+ FILE *fd;
+
+ status = get_shunt_path(cg, path);
+ if (status != SR_OK) {
+ ret = status;
+ goto out;
+ }
+
+ /*
+ * Can't use g_file_set_contents() here, as it calls open() with
+ * O_EXEC flag in a sysfs directory thus failing with EACCES.
+ */
+ fd = g_fopen(path->str, "w");
+ if (!fd) {
+ sr_err("Error opening %s: %s", path->str, strerror(errno));
+ g_string_free(path, TRUE);
+ return SR_ERR_IO;
+ }
+
+ g_string_free(path, TRUE);
+ g_fprintf(fd, "%llu\n", MOHM_TO_UOHM(shunt));
+ /*
+ * XXX There's no g_fclose() in GLib. This seems to work,
+ * but is it safe?
+ */
+ fclose(fd);
+
+out:
+ g_string_free(path, TRUE);
+ return ret;
+}
+
static int channel_to_mq(struct sr_channel *ch)
{
struct channel_priv *chp;
diff --git a/src/hardware/baylibre-acme/protocol.h
b/src/hardware/baylibre-acme/protocol.h
index 5252118..b70182c 100644
--- a/src/hardware/baylibre-acme/protocol.h
+++ b/src/hardware/baylibre-acme/protocol.h
@@ -81,6 +81,11 @@ SR_PRIV gboolean bl_acme_detect_probe(unsigned int addr,
SR_PRIV gboolean bl_acme_register_probe(struct sr_dev_inst *sdi, int type,
unsigned int addr, int prb_num);
+SR_PRIV int bl_acme_get_shunt(const struct sr_channel_group *cg,
+ uint64_t *shunt);
+SR_PRIV int bl_acme_set_shunt(const struct sr_channel_group *cg,
+ uint64_t shunt);
+
SR_PRIV int bl_acme_receive_data(int fd, int revents, void *cb_data);
#endif
--
2.1.4
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