[PATCH 6/9] hwmon: Add support for Photonicat PMU board temperature sensor

[Junhao Xie <bigfoot@classfun.cn>]

Photonicat PMU MCU will send status reports regularly,
including board temperature.

Signed-off-by: Junhao Xie <bigfoot@classfun.cn>
---
 drivers/hwmon/Kconfig            |  10 +++
 drivers/hwmon/Makefile           |   1 +
 drivers/hwmon/photonicat-hwmon.c | 129 +++++++++++++++++++++++++++++++
 3 files changed, 140 insertions(+)
 create mode 100644 drivers/hwmon/photonicat-hwmon.c

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index b60fe2e58ad6..b345e4856bcf 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1781,6 +1781,16 @@ config SENSORS_PT5161L
 	  This driver can also be built as a module. If so, the module
 	  will be called pt5161l.
 
+config SENSORS_PHOTONICAT_PMU_HWMON
+	tristate "Photonicat PMU temperature sensor"
+	depends on MFD_PHOTONICAT_PMU
+	help
+	  If you say yes here you get support for temperature sensor on the
+	  Photonicat PMU.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called photonicat-hwmon.
+
 config SENSORS_PWM_FAN
 	tristate "PWM fan"
 	depends on PWM || COMPILE_TEST
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index b1c7056c37db..a30658acb093 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -183,6 +183,7 @@ obj-$(CONFIG_SENSORS_OXP) += oxp-sensors.o
 obj-$(CONFIG_SENSORS_PC87360)	+= pc87360.o
 obj-$(CONFIG_SENSORS_PC87427)	+= pc87427.o
 obj-$(CONFIG_SENSORS_PCF8591)	+= pcf8591.o
+obj-$(CONFIG_SENSORS_PHOTONICAT_PMU_HWMON)	+= photonicat-hwmon.o
 obj-$(CONFIG_SENSORS_POWERZ)	+= powerz.o
 obj-$(CONFIG_SENSORS_POWR1220)  += powr1220.o
 obj-$(CONFIG_SENSORS_PT5161L)	+= pt5161l.o
diff --git a/drivers/hwmon/photonicat-hwmon.c b/drivers/hwmon/photonicat-hwmon.c
new file mode 100644
index 000000000000..f1e3ee5f5781
--- /dev/null
+++ b/drivers/hwmon/photonicat-hwmon.c
@@ -0,0 +1,129 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2024 Junhao Xie <bigfoot@classfun.cn>
+ */
+
+#include <linux/completion.h>
+#include <linux/hwmon.h>
+#include <linux/mfd/photonicat-pmu.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+
+struct pcat_hwmon {
+	struct device *dev;
+	struct pcat_pmu *pmu;
+	struct notifier_block nb;
+	struct device *hwmon;
+	int temperature;
+	struct completion initial_report;
+};
+
+static ssize_t temp1_input_show(struct device *dev,
+				struct device_attribute *devattr, char *buf)
+{
+	struct pcat_hwmon *hwmon = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%d\n", hwmon->temperature * 1000);
+}
+
+static DEVICE_ATTR_RO(temp1_input);
+
+static struct attribute *pcat_pmu_temp_attrs[] = {
+	&dev_attr_temp1_input.attr,
+	NULL
+};
+
+ATTRIBUTE_GROUPS(pcat_pmu_temp);
+
+static int pcat_hwmon_notify(struct notifier_block *nb, unsigned long action,
+			     void *data)
+{
+	struct pcat_hwmon *hwmon = container_of(nb, struct pcat_hwmon, nb);
+	struct pcat_data_cmd_status *status = pcat_data_get_data(data);
+
+	if (action != PCAT_CMD_STATUS_REPORT)
+		return NOTIFY_DONE;
+
+	hwmon->temperature = status->temp - 40;
+	complete(&hwmon->initial_report);
+
+	return NOTIFY_DONE;
+}
+
+static int pcat_hwmon_probe(struct platform_device *pdev)
+{
+	int ret;
+	struct device *dev = &pdev->dev;
+	struct pcat_hwmon *hwmon;
+	const char *label;
+
+	hwmon = devm_kzalloc(dev, sizeof(*hwmon), GFP_KERNEL);
+	if (!hwmon)
+		return -ENOMEM;
+
+	hwmon->dev = dev;
+	hwmon->pmu = dev_get_drvdata(dev->parent);
+	hwmon->nb.notifier_call = pcat_hwmon_notify;
+	init_completion(&hwmon->initial_report);
+	platform_set_drvdata(pdev, hwmon);
+
+	ret = of_property_read_string(dev->of_node, "label", &label);
+	if (ret)
+		return dev_err_probe(dev, ret, "No label property\n");
+
+	ret = pcat_pmu_register_notify(hwmon->pmu, &hwmon->nb);
+	if (ret)
+		return ret;
+
+	if (!wait_for_completion_timeout(&hwmon->initial_report,
+					 msecs_to_jiffies(3000))) {
+		ret = dev_err_probe(dev, -ETIMEDOUT,
+				    "timeout waiting for initial report\n");
+		goto error;
+	}
+
+	dev_info(dev, "Board Temprature: %d degress C\n", hwmon->temperature);
+
+	hwmon->hwmon = devm_hwmon_device_register_with_groups(
+		dev, label, hwmon, pcat_pmu_temp_groups);
+
+	if (IS_ERR(hwmon->hwmon)) {
+		ret = PTR_ERR(hwmon->hwmon);
+		dev_err_probe(&pdev->dev, ret,
+			      "Failed to register hwmon device\n");
+		goto error;
+	}
+
+	return 0;
+error:
+	pcat_pmu_unregister_notify(hwmon->pmu, &hwmon->nb);
+	return ret;
+}
+
+static void pcat_hwmon_remove(struct platform_device *pdev)
+{
+	struct pcat_hwmon *hwmon = platform_get_drvdata(pdev);
+
+	pcat_pmu_unregister_notify(hwmon->pmu, &hwmon->nb);
+}
+
+static const struct of_device_id pcat_hwmon_dt_ids[] = {
+	{ .compatible = "ariaboard,photonicat-pmu-hwmon", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, pcat_hwmon_dt_ids);
+
+static struct platform_driver pcat_hwmon_driver = {
+	.driver = {
+		.name = "photonicat-hwmon",
+		.of_match_table = pcat_hwmon_dt_ids,
+	},
+	.probe = pcat_hwmon_probe,
+	.remove = pcat_hwmon_remove,
+};
+module_platform_driver(pcat_hwmon_driver);
+
+MODULE_AUTHOR("Junhao Xie <bigfoot@classfun.cn>");
+MODULE_DESCRIPTION("Photonicat PMU Hardware Monitor");
+MODULE_LICENSE("GPL");
-- 
2.46.0