Re: [PATCH 3/5] hwmon: (socfpga) Add hardware monitoring support on SoCFPGA platforms
From: Dinh Nguyen
Date: Mon Apr 17 2023 - 17:00:39 EST
On 4/10/2023 9:44 PM, Guenter Roeck wrote:
On 4/10/23 08:33, dinh.nguyen@xxxxxxxxxxxxxxx wrote:
From: Dinh Nguyen <dinh.nguyen@xxxxxxxxxxxxxxx>
The driver supports 64-bit SoCFPGA platforms for temperature and voltage
reading using the platform's SDM(Secure Device Manager). The driver
also uses the Stratix10 Service layer driver.
This driver only supports OF SoCFPGA 64-bit platforms.
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Signed-off-by: Dinh Nguyen <dinh.nguyen@xxxxxxxxxxxxxxx>
---
Documentation/hwmon/index.rst | 1 +
Documentation/hwmon/socfpga-hwmon.rst | 30 ++
drivers/firmware/stratix10-svc.c | 18 +-
Changes outside the hwmon subsystem need to be in a separate patch.
will separate...
drivers/hwmon/Kconfig | 11 +
drivers/hwmon/Makefile | 1 +
drivers/hwmon/socfpga-hwmon.c | 406 ++++++++++++++++++
include/linux/firmware/intel/stratix10-smc.h | 34 ++
.../firmware/intel/stratix10-svc-client.h | 6 +
8 files changed, 506 insertions(+), 1 deletion(-)
create mode 100644 Documentation/hwmon/socfpga-hwmon.rst
create mode 100644 drivers/hwmon/socfpga-hwmon.c
...
+
+enum hwmon_type_op {
+ SOCFPGA_HWMON_TYPE_TEMP,
+ SOCFPGA_HWMON_TYPE_VOLT,
+ SOCFPGA_HWMON_TYPE_MAX
Unused define
Removed.
+};
+
+static const char *const hwmon_types_str[] = { "temperature",
"voltage" };
+
+static umode_t socfpga_is_visible(const void *dev,
+ enum hwmon_sensor_types type,
+ u32 attr, int chan)
+{
+ switch (type) {
+ case hwmon_temp:
+ case hwmon_in:
+ return 0444;
+ default:
+ return 0;
+ }
+}
+
+static void socfpga_smc_callback(struct stratix10_svc_client *client,
+ struct stratix10_svc_cb_data *data)
+{
+ struct socfpga_hwmon_priv *priv = client->priv;
+ struct arm_smccc_res *res = data->kaddr1;
+
+ if (data->status == BIT(SVC_STATUS_OK)) {
+ if (priv->msg.command == COMMAND_HWMON_READTEMP)
+ priv->temperature.value = res->a0;
+ else
+ priv->voltage.value = res->a0;
+ } else
+ dev_err(client->dev, "%s returned 0x%lX\n", __func__, res->a0);
+
Missing { } in else branch. Please run checkpatch --strict and fix
continuation line alignment issues as well as unbalanced if/else
reports.
Will do.
+ complete(&priv->completion);
+}
+
+static int socfpga_hwmon_send(struct socfpga_hwmon_priv *priv)
+{
+ int ret;
+
+ priv->client.receive_cb = socfpga_smc_callback;
+
+ ret = stratix10_svc_send(priv->chan, &priv->msg);
+ if (ret < 0)
+ return ret;
+
+ if (!wait_for_completion_timeout(&priv->completion,
HWMON_TIMEOUT)) {
+ dev_err(priv->client.dev, "SMC call timeout!\n");
+ return -ETIMEDOUT;
+ }
+
+ return 0;
+}
+
+static int socfpga_hwmon_err_to_errno(struct socfpga_hwmon_priv *priv)
+{
+ int value = priv->temperature.value;
+
+ if (!(value & ETEMP_ERROR))
+ return 0;
+
This is odd. int is normally 32 bit, this function is called from
socfpga_read() for temperatures, which presumably are defined
as "signed 32-bit fixed point binary". That means that negative
temperatures would be treated as errors. Please verify.
That's correct, if bit 31 is set, then it indicates an error.
+ dev_err(priv->client.dev, "temperature sensor code 0x%08x\n",
value);
+
Please don't clog the log with such messages.
Removed.
+ value &= ~ETEMP_ERROR;
+ switch (value) {
+ case ETEMP_NOT_PRESENT:
+ return -ENOENT;
+ case ETEMP_CORRUPT:
+ case ETEMP_NOT_INITIALIZED:
+ return -ENODATA;
+ case ETEMP_BUSY:
+ return -EBUSY;
+ case ETEMP_INACTIVE:
+ case ETEMP_TIMEOUT:
+ case ETEMP_TOO_OLD:
+ return -EAGAIN;
+ default:
+ /* Unknown error */
+ return -EINVAL;
Should be -EIO.
Replaced.
+ }
+}
+
+static int socfpga_read(struct device *dev, enum hwmon_sensor_types
type,
+ u32 attr, int chan, long *val)
+{
+ struct socfpga_hwmon_priv *priv = dev_get_drvdata(dev);
+ int ret;
+
+ mutex_lock(&priv->lock);
+ reinit_completion(&priv->completion);
+
+ switch (type) {
+ case hwmon_temp:
+ priv->msg.arg[0] = BIT_ULL(priv->temperature.chan[chan]);
+ priv->msg.command = COMMAND_HWMON_READTEMP;
+ if (socfpga_hwmon_send(priv))
+ goto status_done;
+
+ ret = socfpga_hwmon_err_to_errno(priv);
+ if (ret)
+ break;
+ /*
+ * The Temperature Sensor IP core returns the Celsius
+ * temperature value in signed 32-bit fixed point binary
+ * format, with eight bits below binary point.
+ */
+ *val = (priv->temperature.value * MILLIDEGREE_PER_DEGREE) /
256;
+ break;
+ case hwmon_in: /* Read voltage */
Pointless comment
Removed.
+ priv->msg.arg[0] = BIT_ULL(priv->voltage.chan[chan]);
+ priv->msg.command = COMMAND_HWMON_READVOLT;
+ if (socfpga_hwmon_send(priv))
+ goto status_done;
+
No error check for voltage sensors ?
Also, unless I am missing something, the error bailout leaves ret
undefined.
There are no error readings for the voltage sensors specified in the
spec. Will update
the ret value.
+ /*
+ * The Voltage Sensor IP core returns the sampled voltage
+ * in unsigned 32-bit fixed point binary format, with 16 bits
+ * below binary point.
+ */
+ *val = (priv->voltage.value * MILLIVOLT_PER_VOLT) / 65536;
+ break;
+ default:
+ ret = -EOPNOTSUPP;
+ break;
+ }
+
+status_done:
+ stratix10_svc_done(priv->chan);
+ mutex_unlock(&priv->lock);
+ return ret;
+}
+
+static int socfpga_read_string(struct device *dev,
+ enum hwmon_sensor_types type, u32 attr,
+ int chan, const char **str)
+{
+ struct socfpga_hwmon_priv *priv = dev_get_drvdata(dev);
+
+ switch (type) {
+ case hwmon_in:
+ *str = priv->voltage.names[chan];
+ return 0;
+ case hwmon_temp:
+ *str = priv->temperature.names[chan];
+ return 0;
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static const struct hwmon_ops socfpga_ops = {
+ .is_visible = socfpga_is_visible,
+ .read = socfpga_read,
+ .read_string = socfpga_read_string,
+};
+
+static const struct hwmon_channel_info *socfpga_info[] = {
+ HWMON_CHANNEL_INFO(temp,
+ HWMON_T_INPUT | HWMON_T_LABEL, HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL, HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL, HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL, HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL, HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL, HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL, HWMON_T_INPUT | HWMON_T_LABEL,
+ HWMON_T_INPUT | HWMON_T_LABEL, HWMON_T_INPUT | HWMON_T_LABEL),
+ HWMON_CHANNEL_INFO(in,
+ HWMON_I_INPUT | HWMON_I_LABEL, HWMON_I_INPUT | HWMON_I_LABEL,
+ HWMON_I_INPUT | HWMON_I_LABEL, HWMON_I_INPUT | HWMON_I_LABEL,
+ HWMON_I_INPUT | HWMON_I_LABEL, HWMON_I_INPUT | HWMON_I_LABEL,
+ HWMON_I_INPUT | HWMON_I_LABEL, HWMON_I_INPUT | HWMON_I_LABEL,
+ HWMON_I_INPUT | HWMON_I_LABEL, HWMON_I_INPUT | HWMON_I_LABEL,
+ HWMON_I_INPUT | HWMON_I_LABEL, HWMON_I_INPUT | HWMON_I_LABEL,
+ HWMON_I_INPUT | HWMON_I_LABEL, HWMON_I_INPUT | HWMON_I_LABEL,
+ HWMON_I_INPUT | HWMON_I_LABEL, HWMON_I_INPUT | HWMON_I_LABEL),
+ NULL
+};
+
+static const struct hwmon_chip_info socfpga_chip_info = {
+ .ops = &socfpga_ops,
+ .info = socfpga_info,
+};
+
+static int socfpga_add_channel(struct device *dev, const char *type,
+ u32 val, const char *label,
+ struct socfpga_hwmon_priv *priv)
+{
+ int type_index;
+ struct socfpga_hwmon_chan *p;
+
+ type_index = match_string(hwmon_types_str,
ARRAY_SIZE(hwmon_types_str), type);
+ switch (type_index) {
+ case SOCFPGA_HWMON_TYPE_TEMP:
+ p = &priv->temperature;
+ break;
+ case SOCFPGA_HWMON_TYPE_VOLT:
+ p = &priv->voltage;
+ break;
+ default:
+ return -ENODATA;
+ }
+ if (p->n >= SOCFPGA_HWMON_MAXSENSORS)
+ return -ENOSPC;
+
+ p->names[p->n] = label;
+ p->chan[p->n] = val;
+ p->n++;
+
+ return 0;
+}
+
+static int socfpga_probe_child_from_dt(struct device *dev,
+ struct device_node *child,
+ struct socfpga_hwmon_priv *priv)
+{
+ struct device_node *grandchild;
+ const char *label;
+ const char *type;
+ u32 val;
+ int ret;
+
+ if (of_property_read_string(child, "name", &type))
+ return dev_err_probe(dev, -EINVAL, "No type for %pOF\n",
child);
+
+ for_each_child_of_node(child, grandchild) {
+ ret = of_property_read_u32(grandchild, "reg", &val);
+ if (ret)
+ return dev_err_probe(dev, ret, "missing reg property of
%pOF\n",
+ grandchild);
+
+ ret = of_property_read_string(grandchild, "label", &label);
+ if (ret)
+ return dev_err_probe(dev, ret, "missing label propoerty
of %pOF\n",
+ grandchild);
+ ret = socfpga_add_channel(dev, type, val, label, priv);
+ if (ret == -ENOSPC)
+ return dev_err_probe(dev, ret, "too many channels, only
%d supported\n",
+ SOCFPGA_HWMON_MAXSENSORS);
+ }
+ return 0;
+}
+
+static int socfpga_probe_from_dt(struct device *dev,
+ struct socfpga_hwmon_priv *priv)
+{
+ const struct device_node *np = dev->of_node;
+ struct device_node *child;
+ int ret = 0;
+
+ for_each_child_of_node(np, child) {
+ ret = socfpga_probe_child_from_dt(dev, child, priv);
+ if (ret)
+ break;
+ }
+ of_node_put(child);
+
+ return ret;
+}
+
+static int socfpga_hwmon_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device *hwmon_dev;
+ struct socfpga_hwmon_priv *priv;
+ int ret;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->client.dev = dev;
+ priv->client.priv = priv;
+
+ ret = socfpga_probe_from_dt(dev, priv);
+ if (ret)
+ return dev_err_probe(dev, ret, "Unable to probe from device
tree\n");
+
+ mutex_init(&priv->lock);
+ init_completion(&priv->completion);
+ hwmon_dev = devm_hwmon_device_register_with_info(dev,
"socfpgahwmon",
+ priv,
+ &socfpga_chip_info,
+ NULL);
+ if (IS_ERR(hwmon_dev))
+ return PTR_ERR(hwmon_dev);
+
+ priv->chan = stratix10_svc_request_channel_byname(&priv->client,
+ SVC_CLIENT_HWMON);
This is racy: hwmon attributes exist here, and priv->chan may be
accessed before
it is set.
Fixed in v2.
+ if (IS_ERR(priv->chan))
+ return dev_err_probe(dev, PTR_ERR(priv->chan),
+ "couldn't get service channel %s\n",
+ SVC_CLIENT_RSU);
+
+ platform_set_drvdata(pdev, priv);
+
+ return 0;
+}
+
+static int socfpga_hwmon_remove(struct platform_device *pdev)
+{
+ struct socfpga_hwmon_priv *priv = platform_get_drvdata(pdev);
+
+ stratix10_svc_free_channel(priv->chan);
This releases the channel before the hwmon device is released.
Another race condition.
fixed in V2.
Thanks for the review!
Dinh