[PATCH v8 11/12] hwmon: Add PECI dimmtemp driver

[Jae Hyun Yoo]

This commit adds PECI dimmtemp hwmon driver.

Cc: Jean Delvare <jdelvare@xxxxxxxx>
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>
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>
Acked-by: Guenter Roeck <linux@xxxxxxxxxxxx>
---
 drivers/hwmon/Kconfig         |  14 ++
 drivers/hwmon/Makefile        |   1 +
 drivers/hwmon/peci-dimmtemp.c | 286 ++++++++++++++++++++++++++++++++++
 3 files changed, 301 insertions(+)
 create mode 100644 drivers/hwmon/peci-dimmtemp.c

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index f08b4a670ac5..d2299d850508 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1320,6 +1320,20 @@ 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 PECI
+	select MFD_INTEL_PECI_CLIENT
+	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.
+
 source drivers/hwmon/pmbus/Kconfig
 
 config SENSORS_PWM_FAN
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 13ebde089ad5..b7cf35bcfbaf 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -142,6 +142,7 @@ obj-$(CONFIG_SENSORS_PC87360)	+= pc87360.o
 obj-$(CONFIG_SENSORS_PC87427)	+= pc87427.o
 obj-$(CONFIG_SENSORS_PCF8591)	+= pcf8591.o
 obj-$(CONFIG_SENSORS_PECI_CPUTEMP)	+= peci-cputemp.o
+obj-$(CONFIG_SENSORS_PECI_DIMMTEMP)	+= peci-dimmtemp.o
 obj-$(CONFIG_SENSORS_POWR1220)  += powr1220.o
 obj-$(CONFIG_SENSORS_PWM_FAN)	+= pwm-fan.o
 obj-$(CONFIG_SENSORS_RASPBERRYPI_HWMON)	+= raspberrypi-hwmon.o
diff --git a/drivers/hwmon/peci-dimmtemp.c b/drivers/hwmon/peci-dimmtemp.c
new file mode 100644
index 000000000000..0b0155fa627b
--- /dev/null
+++ b/drivers/hwmon/peci-dimmtemp.c
@@ -0,0 +1,286 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2018 Intel Corporation
+
+#include <linux/hwmon.h>
+#include <linux/jiffies.h>
+#include <linux/mfd/intel-peci-client.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/workqueue.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_mfd *mfd;
+	struct device *dev;
+	char name[PECI_NAME_SIZE];
+	u8 addr;
+	const struct cpu_gen_info *gen_info;
+	struct workqueue_struct *work_queue;
+	struct delayed_work work_handler;
+	struct temp_data temp[DIMM_NUMS_MAX];
+	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 A1", "DIMM A2", "DIMM A3" },
+	{ "DIMM B1", "DIMM B2", "DIMM B3" },
+	{ "DIMM C1", "DIMM C2", "DIMM C3" },
+	{ "DIMM D1", "DIMM D2", "DIMM D3" },
+	{ "DIMM E1", "DIMM E2", "DIMM E3" },
+	{ "DIMM F1", "DIMM F2", "DIMM F3" },
+	{ "DIMM G1", "DIMM G2", "DIMM G3" },
+	{ "DIMM H1", "DIMM H2", "DIMM H3" },
+};
+
+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_temp_need_update(&priv->temp[dimm_no]))
+		return 0;
+
+	rc = peci_client_rd_pkg_cfg_cmd(priv->mfd, MBX_INDEX_DDR_DIMM_TEMP,
+					chan_rank, cfg_data);
+	if (rc)
+		return rc;
+
+	priv->temp[dimm_no].value = cfg_data[dimm_order] * 1000;
+
+	peci_temp_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_client_rd_pkg_cfg_cmd(priv->mfd,
+						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 *
+						       dimm_idx_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 platform_device *pdev)
+{
+	struct peci_mfd *mfd = dev_get_drvdata(pdev->dev.parent);
+	struct device *dev = &pdev->dev;
+	struct peci_dimmtemp *priv;
+	int rc;
+
+	if ((mfd->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->mfd = mfd;
+	priv->dev = dev;
+	priv->addr = mfd->addr;
+	priv->gen_info = mfd->gen_info;
+
+	snprintf(priv->name, PECI_NAME_SIZE, "peci_dimmtemp.cpu%d",
+		 priv->mfd->cpu_no);
+
+	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 platform_device *pdev)
+{
+	struct peci_dimmtemp *priv = dev_get_drvdata(&pdev->dev);
+
+	cancel_delayed_work_sync(&priv->work_handler);
+	destroy_workqueue(priv->work_queue);
+
+	return 0;
+}
+
+static const struct platform_device_id peci_dimmtemp_ids[] = {
+	{ .name = "peci-dimmtemp", .driver_data = 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(platform, peci_dimmtemp_ids);
+
+static struct platform_driver peci_dimmtemp_driver = {
+	.probe    = peci_dimmtemp_probe,
+	.remove   = peci_dimmtemp_remove,
+	.id_table = peci_dimmtemp_ids,
+	.driver   = {
+			.name           = "peci-dimmtemp",
+	},
+};
+module_platform_driver(peci_dimmtemp_driver);
+
+MODULE_AUTHOR("Jae Hyun Yoo <jae.hyun.yoo@xxxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("PECI dimmtemp driver");
+MODULE_LICENSE("GPL v2");
-- 
2.18.0