Re: [v4 10/11] drivers/hwmon: Add PECI dimmtemp driver

From: Guenter Roeck
Date: Mon May 21 2018 - 15:45:04 EST


On Mon, May 21, 2018 at 01:00:02PM -0700, Jae Hyun Yoo wrote:
> This commit adds PECI dimmtemp hwmon driver.
>
> Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@xxxxxxxxxxxxxxx>
> Reviewed-by: Haiyue Wang <haiyue.wang@xxxxxxxxxxxxxxx>
> Reviewed-by: James Feist <james.feist@xxxxxxxxxxxxxxx>
> Reviewed-by: Vernon Mauery <vernon.mauery@xxxxxxxxxxxxxxx>
> Cc: Alan Cox <alan@xxxxxxxxxxxxxxx>
> Cc: Andrew Jeffery <andrew@xxxxxxxx>
> Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> Cc: Arnd Bergmann <arnd@xxxxxxxx>
> Cc: Jason M Biils <jason.m.bills@xxxxxxxxxxxxxxx>
> Cc: Joel Stanley <joel@xxxxxxxxx>
> Cc: Miguel Ojeda <miguel.ojeda.sandonis@xxxxxxxxx>
> Cc: Andrew Lunn <andrew@xxxxxxx>
> Cc: Stef van Os <stef.van.os@xxxxxxxxxxxxxxxxxxxxxxxxx>
> ---
> drivers/hwmon/Kconfig | 14 ++
> drivers/hwmon/Makefile | 1 +
> drivers/hwmon/peci-dimmtemp.c | 300 ++++++++++++++++++++++++++++++++++
> 3 files changed, 315 insertions(+)
> create mode 100644 drivers/hwmon/peci-dimmtemp.c
>
> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
> index 8492586bb1e4..6ce5c03ec544 100644
> --- a/drivers/hwmon/Kconfig
> +++ b/drivers/hwmon/Kconfig
> @@ -1270,6 +1270,20 @@ config SENSORS_PECI_CPUTEMP
> This driver can also be built as a module. If so, the module
> will be called peci-cputemp.
>
> +config SENSORS_PECI_DIMMTEMP
> + tristate "PECI DIMM temperature monitoring support"
> + depends on OF
> + depends on PECI
> + help
> + If you say yes here you get support for the generic Intel PECI hwmon
> + driver which provides Digital Thermal Sensor (DTS) thermal readings of
> + DIMM components that are accessible using the PECI Client Command
> + Suite via the processor PECI client.
> + Check Documentation/hwmon/peci-dimmtemp for details.
> +
> + This driver can also be built as a module. If so, the module
> + will be called peci-dimmtemp.
> +
> config SENSORS_NSA320
> tristate "ZyXEL NSA320 and compatible fan speed and temperature sensors"
> depends on GPIOLIB && OF
> diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
> index d18b374a9000..1662bbe08ea9 100644
> --- a/drivers/hwmon/Makefile
> +++ b/drivers/hwmon/Makefile
> @@ -137,6 +137,7 @@ obj-$(CONFIG_SENSORS_NCT7904) += nct7904.o
> obj-$(CONFIG_SENSORS_NSA320) += nsa320-hwmon.o
> obj-$(CONFIG_SENSORS_NTC_THERMISTOR) += ntc_thermistor.o
> obj-$(CONFIG_SENSORS_PECI_CPUTEMP) += peci-cputemp.o peci-hwmon.o
> +obj-$(CONFIG_SENSORS_PECI_DIMMTEMP) += peci-dimmtemp.o peci-hwmon.o
> obj-$(CONFIG_SENSORS_PC87360) += pc87360.o
> obj-$(CONFIG_SENSORS_PC87427) += pc87427.o
> obj-$(CONFIG_SENSORS_PCF8591) += pcf8591.o
> diff --git a/drivers/hwmon/peci-dimmtemp.c b/drivers/hwmon/peci-dimmtemp.c
> new file mode 100644
> index 000000000000..898de1c38e55
> --- /dev/null
> +++ b/drivers/hwmon/peci-dimmtemp.c
> @@ -0,0 +1,300 @@
> +// SPDX-License-Identifier: GPL-2.0
> +// Copyright (c) 2018 Intel Corporation
> +
> +#include <linux/hwmon.h>
> +#include <linux/jiffies.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/workqueue.h>
> +
> +#include "peci-hwmon.h"
> +
> +#define DIMM_MASK_CHECK_DELAY_JIFFIES msecs_to_jiffies(5000)
> +#define DIMM_MASK_CHECK_RETRY_MAX 60 /* 60 x 5 secs = 5 minutes */
> +
> +struct peci_dimmtemp {
> + struct peci_client *client;
> + struct device *dev;
> + struct workqueue_struct *work_queue;
> + struct delayed_work work_handler;
> + char name[PECI_NAME_SIZE];
> + struct temp_data temp[DIMM_NUMS_MAX];
> + u8 addr;
> + uint cpu_no;
> + const struct cpu_gen_info *gen_info;
> + u32 dimm_mask;
> + int retry_count;
> + u32 temp_config[DIMM_NUMS_MAX + 1];
> + struct hwmon_channel_info temp_info;
> + const struct hwmon_channel_info *info[2];
> + struct hwmon_chip_info chip;
> +};
> +
> +static const char *dimmtemp_label[CHAN_RANK_MAX][DIMM_IDX_MAX] = {
> + { "DIMM A0", "DIMM A1", "DIMM A2" },
> + { "DIMM B0", "DIMM B1", "DIMM B2" },
> + { "DIMM C0", "DIMM C1", "DIMM C2" },
> + { "DIMM D0", "DIMM D1", "DIMM D2" },
> + { "DIMM E0", "DIMM E1", "DIMM E2" },
> + { "DIMM F0", "DIMM F1", "DIMM F2" },
> + { "DIMM G0", "DIMM G1", "DIMM G2" },
> + { "DIMM H0", "DIMM H1", "DIMM H2" },
> +};
> +
> +static int get_dimm_temp(struct peci_dimmtemp *priv, int dimm_no)
> +{
> + int dimm_order = dimm_no % priv->gen_info->dimm_idx_max;
> + int chan_rank = dimm_no / priv->gen_info->dimm_idx_max;
> + u8 cfg_data[4];
> + int rc;
> +
> + if (!peci_hwmon_need_update(&priv->temp[dimm_no]))
> + return 0;

Quick feedback:

This function is defined in peci-hwmon.c, which is built only if
SENSORS_PECI_CPUTEMP is enabled (though as a separate module).
I would suggest to add a separate auto-selected configuration
flag such as SENSORS_PECI_HWMON for peci-hwmon.c and select it
from both SENSORS_PECI_CPUTEMP and SENSORS_PECI_DIMMTEMP.

Guenter

> +
> + rc = peci_hwmon_rd_pkg_cfg_cmd(priv->client->adapter, priv->addr,
> + MBX_INDEX_DDR_DIMM_TEMP,
> + chan_rank, cfg_data);
> + if (rc)
> + return rc;
> +
> + priv->temp[dimm_no].value = cfg_data[dimm_order] * 1000;
> +
> + peci_hwmon_mark_updated(&priv->temp[dimm_no]);
> +
> + return 0;
> +}
> +
> +static int dimmtemp_read_string(struct device *dev,
> + enum hwmon_sensor_types type,
> + u32 attr, int channel, const char **str)
> +{
> + struct peci_dimmtemp *priv = dev_get_drvdata(dev);
> + u32 dimm_idx_max = priv->gen_info->dimm_idx_max;
> + int chan_rank, dimm_idx;
> +
> + if (attr != hwmon_temp_label)
> + return -EOPNOTSUPP;
> +
> + chan_rank = channel / dimm_idx_max;
> + dimm_idx = channel % dimm_idx_max;
> + *str = dimmtemp_label[chan_rank][dimm_idx];
> + return 0;
> +}
> +
> +static int dimmtemp_read(struct device *dev, enum hwmon_sensor_types type,
> + u32 attr, int channel, long *val)
> +{
> + struct peci_dimmtemp *priv = dev_get_drvdata(dev);
> + int rc;
> +
> + if (attr != hwmon_temp_input)
> + return -EOPNOTSUPP;
> +
> + rc = get_dimm_temp(priv, channel);
> + if (rc)
> + return rc;
> +
> + *val = priv->temp[channel].value;
> + return 0;
> +}
> +
> +static umode_t dimmtemp_is_visible(const void *data,
> + enum hwmon_sensor_types type,
> + u32 attr, int channel)
> +{
> + const struct peci_dimmtemp *priv = data;
> +
> + if (priv->temp_config[channel] & BIT(attr) &&
> + priv->dimm_mask & BIT(channel))
> + return 0444;
> +
> + return 0;
> +}
> +
> +static const struct hwmon_ops dimmtemp_ops = {
> + .is_visible = dimmtemp_is_visible,
> + .read_string = dimmtemp_read_string,
> + .read = dimmtemp_read,
> +};
> +
> +static int check_populated_dimms(struct peci_dimmtemp *priv)
> +{
> + u32 chan_rank_max = priv->gen_info->chan_rank_max;
> + u32 dimm_idx_max = priv->gen_info->dimm_idx_max;
> + int chan_rank, dimm_idx, rc;
> + u8 cfg_data[4];
> +
> + for (chan_rank = 0; chan_rank < chan_rank_max; chan_rank++) {
> + rc = peci_hwmon_rd_pkg_cfg_cmd(priv->client->adapter,
> + priv->addr,
> + MBX_INDEX_DDR_DIMM_TEMP,
> + chan_rank, cfg_data);
> + if (rc) {
> + priv->dimm_mask = 0;
> + return rc;
> + }
> +
> + for (dimm_idx = 0; dimm_idx < dimm_idx_max; dimm_idx++)
> + if (cfg_data[dimm_idx])
> + priv->dimm_mask |= BIT(chan_rank *
> + chan_rank_max +
> + dimm_idx);
> + }
> +
> + if (!priv->dimm_mask)
> + return -EAGAIN;
> +
> + dev_dbg(priv->dev, "Scanned populated DIMMs: 0x%x\n", priv->dimm_mask);
> + return 0;
> +}
> +
> +static int create_dimm_temp_info(struct peci_dimmtemp *priv)
> +{
> + int rc, i, config_idx, channels;
> + struct device *hwmon_dev;
> +
> + rc = check_populated_dimms(priv);
> + if (rc) {
> + if (rc == -EAGAIN) {
> + if (priv->retry_count < DIMM_MASK_CHECK_RETRY_MAX) {
> + queue_delayed_work(priv->work_queue,
> + &priv->work_handler,
> + DIMM_MASK_CHECK_DELAY_JIFFIES);
> + priv->retry_count++;
> + dev_dbg(priv->dev,
> + "Deferred DIMM temp info creation\n");
> + } else {
> + dev_err(priv->dev,
> + "Timeout DIMM temp info creation\n");
> + rc = -ETIMEDOUT;
> + }
> + }
> +
> + return rc;
> + }
> +
> + channels = priv->gen_info->chan_rank_max *
> + priv->gen_info->dimm_idx_max;
> + for (i = 0, config_idx = 0; i < channels; i++)
> + if (priv->dimm_mask & BIT(i))
> + while (i >= config_idx)
> + priv->temp_config[config_idx++] =
> + HWMON_T_LABEL | HWMON_T_INPUT;
> +
> + priv->chip.ops = &dimmtemp_ops;
> + priv->chip.info = priv->info;
> +
> + priv->info[0] = &priv->temp_info;
> +
> + priv->temp_info.type = hwmon_temp;
> + priv->temp_info.config = priv->temp_config;
> +
> + hwmon_dev = devm_hwmon_device_register_with_info(priv->dev,
> + priv->name,
> + priv,
> + &priv->chip,
> + NULL);
> + rc = PTR_ERR_OR_ZERO(hwmon_dev);
> + if (!rc)
> + dev_dbg(priv->dev, "%s: sensor '%s'\n",
> + dev_name(hwmon_dev), priv->name);
> +
> + return rc;
> +}
> +
> +static void create_dimm_temp_info_delayed(struct work_struct *work)
> +{
> + struct delayed_work *dwork = to_delayed_work(work);
> + struct peci_dimmtemp *priv = container_of(dwork, struct peci_dimmtemp,
> + work_handler);
> + int rc;
> +
> + rc = create_dimm_temp_info(priv);
> + if (rc && rc != -EAGAIN)
> + dev_dbg(priv->dev, "Failed to create DIMM temp info\n");
> +}
> +
> +static int peci_dimmtemp_probe(struct peci_client *client)
> +{
> + struct device *dev = &client->dev;
> + struct peci_dimmtemp *priv;
> + int rc;
> +
> + if ((client->adapter->cmd_mask &
> + (BIT(PECI_CMD_GET_TEMP) | BIT(PECI_CMD_RD_PKG_CFG))) !=
> + (BIT(PECI_CMD_GET_TEMP) | BIT(PECI_CMD_RD_PKG_CFG)))
> + return -ENODEV;
> +
> + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> + if (!priv)
> + return -ENOMEM;
> +
> + dev_set_drvdata(dev, priv);
> + priv->client = client;
> + priv->dev = dev;
> + priv->addr = client->addr;
> + priv->cpu_no = priv->addr - PECI_BASE_ADDR;
> +
> + snprintf(priv->name, PECI_NAME_SIZE, "peci_dimmtemp.cpu%d",
> + priv->cpu_no);
> +
> + rc = peci_hwmon_get_cpu_gen_info(client->adapter, priv->addr,
> + &priv->gen_info);
> + if (rc)
> + return rc;
> +
> + priv->work_queue = alloc_ordered_workqueue(priv->name, 0);
> + if (!priv->work_queue)
> + return -ENOMEM;
> +
> + INIT_DELAYED_WORK(&priv->work_handler, create_dimm_temp_info_delayed);
> +
> + rc = create_dimm_temp_info(priv);
> + if (rc && rc != -EAGAIN) {
> + dev_err(dev, "Failed to create DIMM temp info\n");
> + goto err_free_wq;
> + }
> +
> + return 0;
> +
> +err_free_wq:
> + destroy_workqueue(priv->work_queue);
> + return rc;
> +}
> +
> +static int peci_dimmtemp_remove(struct peci_client *client)
> +{
> + struct peci_dimmtemp *priv = dev_get_drvdata(&client->dev);
> +
> + cancel_delayed_work_sync(&priv->work_handler);
> + destroy_workqueue(priv->work_queue);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id peci_dimmtemp_of_table[] = {
> + { .compatible = "intel,peci-dimmtemp" },
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, peci_dimmtemp_of_table);
> +
> +static const struct peci_device_id peci_dimmtemp_ids[] = {
> + { "peci-dimmtemp", 0, },
> + { }
> +};
> +MODULE_DEVICE_TABLE(peci, peci_dimmtemp_ids);
> +
> +static struct peci_driver peci_dimmtemp_driver = {
> + .probe = peci_dimmtemp_probe,
> + .remove = peci_dimmtemp_remove,
> + .id_table = peci_dimmtemp_ids,
> + .driver = {
> + .name = "peci-dimmtemp",
> + .of_match_table = of_match_ptr(peci_dimmtemp_of_table),
> + },
> +};
> +module_peci_driver(peci_dimmtemp_driver);
> +
> +MODULE_AUTHOR("Jae Hyun Yoo <jae.hyun.yoo@xxxxxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("PECI dimmtemp driver");
> +MODULE_LICENSE("GPL v2");
> --
> 2.17.0
>