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Message-ID: <a3e966f8-8e9d-7081-1665-9d2e87acb310@linux.intel.com>
Date: Mon, 17 Apr 2023 15:55:31 -0500
From: Dinh Nguyen <dinh.nguyen@...ux.intel.com>
To: Guenter Roeck <linux@...ck-us.net>, linux-hwmon@...r.kernel.org
Cc: dinguyen@...nel.org, devicetree@...r.kernel.org,
robh+dt@...nel.org, krzysztof.kozlowski+dt@...aro.org,
linux-kernel@...r.kernel.org, jdelvare@...e.com,
Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Subject: Re: [PATCH 3/5] hwmon: (socfpga) Add hardware monitoring support on
SoCFPGA platforms
On 4/10/2023 9:44 PM, Guenter Roeck wrote:
> On 4/10/23 08:33, dinh.nguyen@...ux.intel.com wrote:
>> From: Dinh Nguyen <dinh.nguyen@...ux.intel.com>
>>
>> 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@...ux.intel.com>
>> Signed-off-by: Dinh Nguyen <dinh.nguyen@...ux.intel.com>
>> ---
>> 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
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