1 files changed, 300 insertions, 0 deletions
diff --git a/drivers/thermal/da9062-thermal.c b/drivers/thermal/da9062-thermal.c
new file mode 100644
index 000000000..4d74994f1
--- /dev/null
+++ b/drivers/thermal/da9062-thermal.c
@@ -0,0 +1,300 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Thermal device driver for DA9062 and DA9061
+ * Copyright (C) 2017  Dialog Semiconductor
+ */
+
+/* When over-temperature is reached, an interrupt from the device will be
+ * triggered. Following this event the interrupt will be disabled and
+ * periodic transmission of uevents (HOT trip point) should define the
+ * first level of temperature supervision. It is expected that any final
+ * implementation of the thermal driver will include a .notify() function
+ * to implement these uevents to userspace.
+ *
+ * These uevents are intended to indicate non-invasive temperature control
+ * of the system, where the necessary measures for cooling are the
+ * responsibility of the host software. Once the temperature falls again,
+ * the IRQ is re-enabled so the start of a new over-temperature event can
+ * be detected without constant software monitoring.
+ */
+
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/thermal.h>
+#include <linux/workqueue.h>
+
+#include <linux/mfd/da9062/core.h>
+#include <linux/mfd/da9062/registers.h>
+
+/* Minimum, maximum and default polling millisecond periods are provided
+ * here as an example. It is expected that any final implementation to also
+ * include a modification of these settings to match the required
+ * application.
+ */
+#define DA9062_DEFAULT_POLLING_MS_PERIOD	3000
+#define DA9062_MAX_POLLING_MS_PERIOD		10000
+#define DA9062_MIN_POLLING_MS_PERIOD		1000
+
+#define DA9062_MILLI_CELSIUS(t)			((t) * 1000)
+
+struct da9062_thermal_config {
+	const char *name;
+};
+
+struct da9062_thermal {
+	struct da9062 *hw;
+	struct delayed_work work;
+	struct thermal_zone_device *zone;
+	struct mutex lock; /* protection for da9062_thermal temperature */
+	int temperature;
+	int irq;
+	const struct da9062_thermal_config *config;
+	struct device *dev;
+};
+
+static void da9062_thermal_poll_on(struct work_struct *work)
+{
+	struct da9062_thermal *thermal = container_of(work,
+						struct da9062_thermal,
+						work.work);
+	unsigned long delay;
+	unsigned int val;
+	int ret;
+
+	/* clear E_TEMP */
+	ret = regmap_write(thermal->hw->regmap,
+			   DA9062AA_EVENT_B,
+			   DA9062AA_E_TEMP_MASK);
+	if (ret < 0) {
+		dev_err(thermal->dev,
+			"Cannot clear the TJUNC temperature status\n");
+		goto err_enable_irq;
+	}
+
+	/* Now read E_TEMP again: it is acting like a status bit.
+	 * If over-temperature, then this status will be true.
+	 * If not over-temperature, this status will be false.
+	 */
+	ret = regmap_read(thermal->hw->regmap,
+			  DA9062AA_EVENT_B,
+			  &val);
+	if (ret < 0) {
+		dev_err(thermal->dev,
+			"Cannot check the TJUNC temperature status\n");
+		goto err_enable_irq;
+	}
+
+	if (val & DA9062AA_E_TEMP_MASK) {
+		mutex_lock(&thermal->lock);
+		thermal->temperature = DA9062_MILLI_CELSIUS(125);
+		mutex_unlock(&thermal->lock);
+		thermal_zone_device_update(thermal->zone,
+					   THERMAL_EVENT_UNSPECIFIED);
+
+		delay = msecs_to_jiffies(thermal->zone->passive_delay);
+		queue_delayed_work(system_freezable_wq, &thermal->work, delay);
+		return;
+	}
+
+	mutex_lock(&thermal->lock);
+	thermal->temperature = DA9062_MILLI_CELSIUS(0);
+	mutex_unlock(&thermal->lock);
+	thermal_zone_device_update(thermal->zone,
+				   THERMAL_EVENT_UNSPECIFIED);
+
+err_enable_irq:
+	enable_irq(thermal->irq);
+}
+
+static irqreturn_t da9062_thermal_irq_handler(int irq, void *data)
+{
+	struct da9062_thermal *thermal = data;
+
+	disable_irq_nosync(thermal->irq);
+	queue_delayed_work(system_freezable_wq, &thermal->work, 0);
+
+	return IRQ_HANDLED;
+}
+
+static int da9062_thermal_get_trip_type(struct thermal_zone_device *z,
+					int trip,
+					enum thermal_trip_type *type)
+{
+	struct da9062_thermal *thermal = z->devdata;
+
+	switch (trip) {
+	case 0:
+		*type = THERMAL_TRIP_HOT;
+		break;
+	default:
+		dev_err(thermal->dev,
+			"Driver does not support more than 1 trip-wire\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int da9062_thermal_get_trip_temp(struct thermal_zone_device *z,
+					int trip,
+					int *temp)
+{
+	struct da9062_thermal *thermal = z->devdata;
+
+	switch (trip) {
+	case 0:
+		*temp = DA9062_MILLI_CELSIUS(125);
+		break;
+	default:
+		dev_err(thermal->dev,
+			"Driver does not support more than 1 trip-wire\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int da9062_thermal_get_temp(struct thermal_zone_device *z,
+				   int *temp)
+{
+	struct da9062_thermal *thermal = z->devdata;
+
+	mutex_lock(&thermal->lock);
+	*temp = thermal->temperature;
+	mutex_unlock(&thermal->lock);
+
+	return 0;
+}
+
+static struct thermal_zone_device_ops da9062_thermal_ops = {
+	.get_temp	= da9062_thermal_get_temp,
+	.get_trip_type	= da9062_thermal_get_trip_type,
+	.get_trip_temp	= da9062_thermal_get_trip_temp,
+};
+
+static const struct da9062_thermal_config da9062_config = {
+	.name = "da9062-thermal",
+};
+
+static const struct of_device_id da9062_compatible_reg_id_table[] = {
+	{ .compatible = "dlg,da9062-thermal", .data = &da9062_config },
+	{ },
+};
+
+MODULE_DEVICE_TABLE(of, da9062_compatible_reg_id_table);
+
+static int da9062_thermal_probe(struct platform_device *pdev)
+{
+	struct da9062 *chip = dev_get_drvdata(pdev->dev.parent);
+	struct da9062_thermal *thermal;
+	unsigned int pp_tmp = DA9062_DEFAULT_POLLING_MS_PERIOD;
+	const struct of_device_id *match;
+	int ret = 0;
+
+	match = of_match_node(da9062_compatible_reg_id_table,
+			      pdev->dev.of_node);
+	if (!match)
+		return -ENXIO;
+
+	if (pdev->dev.of_node) {
+		if (!of_property_read_u32(pdev->dev.of_node,
+					  "polling-delay-passive",
+					  &pp_tmp)) {
+			if (pp_tmp < DA9062_MIN_POLLING_MS_PERIOD ||
+			    pp_tmp > DA9062_MAX_POLLING_MS_PERIOD) {
+				dev_warn(&pdev->dev,
+					 "Out-of-range polling period %d ms\n",
+					 pp_tmp);
+				pp_tmp = DA9062_DEFAULT_POLLING_MS_PERIOD;
+			}
+		}
+	}
+
+	thermal = devm_kzalloc(&pdev->dev, sizeof(struct da9062_thermal),
+			       GFP_KERNEL);
+	if (!thermal) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	thermal->config = match->data;
+	thermal->hw = chip;
+	thermal->dev = &pdev->dev;
+
+	INIT_DELAYED_WORK(&thermal->work, da9062_thermal_poll_on);
+	mutex_init(&thermal->lock);
+
+	thermal->zone = thermal_zone_device_register(thermal->config->name,
+					1, 0, thermal,
+					&da9062_thermal_ops, NULL, pp_tmp,
+					0);
+	if (IS_ERR(thermal->zone)) {
+		dev_err(&pdev->dev, "Cannot register thermal zone device\n");
+		ret = PTR_ERR(thermal->zone);
+		goto err;
+	}
+	ret = thermal_zone_device_enable(thermal->zone);
+	if (ret) {
+		dev_err(&pdev->dev, "Cannot enable thermal zone device\n");
+		goto err_zone;
+	}
+
+	dev_dbg(&pdev->dev,
+		"TJUNC temperature polling period set at %d ms\n",
+		thermal->zone->passive_delay);
+
+	ret = platform_get_irq_byname(pdev, "THERMAL");
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Failed to get platform IRQ.\n");
+		goto err_zone;
+	}
+	thermal->irq = ret;
+
+	ret = request_threaded_irq(thermal->irq, NULL,
+				   da9062_thermal_irq_handler,
+				   IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+				   "THERMAL", thermal);
+	if (ret) {
+		dev_err(&pdev->dev,
+			"Failed to request thermal device IRQ.\n");
+		goto err_zone;
+	}
+
+	platform_set_drvdata(pdev, thermal);
+	return 0;
+
+err_zone:
+	thermal_zone_device_unregister(thermal->zone);
+err:
+	return ret;
+}
+
+static int da9062_thermal_remove(struct platform_device *pdev)
+{
+	struct	da9062_thermal *thermal = platform_get_drvdata(pdev);
+
+	free_irq(thermal->irq, thermal);
+	cancel_delayed_work_sync(&thermal->work);
+	thermal_zone_device_unregister(thermal->zone);
+	return 0;
+}
+
+static struct platform_driver da9062_thermal_driver = {
+	.probe	= da9062_thermal_probe,
+	.remove	= da9062_thermal_remove,
+	.driver	= {
+		.name	= "da9062-thermal",
+		.of_match_table = da9062_compatible_reg_id_table,
+	},
+};
+
+module_platform_driver(da9062_thermal_driver);
+
+MODULE_AUTHOR("Steve Twiss");
+MODULE_DESCRIPTION("Thermal TJUNC device driver for Dialog DA9062 and DA9061");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:da9062-thermal");