[RFC PATCH v5 7/9] media: chips-media: wave6: Add Wave6 thermal cooling device

[Nas Chung <nas.chung@chipsnmedia.com>]

Add a thermal cooling device for the Wave6 VPU.
The device operates within the Linux thermal framework,
adjusting the VPU performance state based on thermal conditions.

Signed-off-by: Nas Chung <nas.chung@chipsnmedia.com>
Tested-by: Ming Qian <ming.qian@oss.nxp.com>
Tested-by: Marek Vasut <marek.vasut@mailbox.org>
---
 .../chips-media/wave6/wave6-vpu-thermal.c     | 141 ++++++++++++++++++
 .../chips-media/wave6/wave6-vpu-thermal.h     |  26 ++++
 2 files changed, 167 insertions(+)
 create mode 100644 drivers/media/platform/chips-media/wave6/wave6-vpu-thermal.c
 create mode 100644 drivers/media/platform/chips-media/wave6/wave6-vpu-thermal.h

diff --git a/drivers/media/platform/chips-media/wave6/wave6-vpu-thermal.c b/drivers/media/platform/chips-media/wave6/wave6-vpu-thermal.c
new file mode 100644
index 000000000000..df8161fd4998
--- /dev/null
+++ b/drivers/media/platform/chips-media/wave6/wave6-vpu-thermal.c
@@ -0,0 +1,141 @@
+// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+/*
+ * Wave6 series multi-standard codec IP - wave6 thermal cooling interface
+ *
+ * Copyright (C) 2025 CHIPS&MEDIA INC
+ *
+ */
+
+#include <linux/pm_domain.h>
+#include <linux/pm_opp.h>
+#include <linux/units.h>
+#include <linux/slab.h>
+#include "wave6-vpu-thermal.h"
+
+static int wave6_vpu_thermal_cooling_update(struct vpu_thermal_cooling *thermal,
+					    int state)
+{
+	unsigned long new_clock_rate;
+	int ret;
+
+	if (state > thermal->thermal_max || !thermal->cooling)
+		return 0;
+
+	new_clock_rate = DIV_ROUND_UP(thermal->freq_table[state], HZ_PER_KHZ);
+	dev_dbg(thermal->dev, "receive cooling state: %d, new clock rate %ld\n",
+		state, new_clock_rate);
+
+	ret = dev_pm_genpd_set_performance_state(thermal->dev, new_clock_rate);
+	if (ret && !((ret == -ENODEV) || (ret == -EOPNOTSUPP))) {
+		dev_err(thermal->dev, "failed to set perf to %lu, ret = %d\n",
+			new_clock_rate, ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int wave6_vpu_cooling_get_max_state(struct thermal_cooling_device *cdev,
+					   unsigned long *state)
+{
+	struct vpu_thermal_cooling *thermal = cdev->devdata;
+
+	*state = thermal->thermal_max;
+
+	return 0;
+}
+
+static int wave6_vpu_cooling_get_cur_state(struct thermal_cooling_device *cdev,
+					   unsigned long *state)
+{
+	struct vpu_thermal_cooling *thermal = cdev->devdata;
+
+	*state = thermal->thermal_event;
+
+	return 0;
+}
+
+static int wave6_vpu_cooling_set_cur_state(struct thermal_cooling_device *cdev,
+					   unsigned long state)
+{
+	struct vpu_thermal_cooling *thermal = cdev->devdata;
+
+	thermal->thermal_event = state;
+	wave6_vpu_thermal_cooling_update(thermal, state);
+
+	return 0;
+}
+
+static struct thermal_cooling_device_ops wave6_cooling_ops = {
+	.get_max_state = wave6_vpu_cooling_get_max_state,
+	.get_cur_state = wave6_vpu_cooling_get_cur_state,
+	.set_cur_state = wave6_vpu_cooling_set_cur_state,
+};
+
+int wave6_vpu_cooling_init(struct vpu_thermal_cooling *thermal)
+{
+	int i;
+	int num_opps;
+	unsigned long freq;
+
+	if (WARN_ON(!thermal || !thermal->dev))
+		return -EINVAL;
+
+	num_opps = dev_pm_opp_get_opp_count(thermal->dev);
+	if (num_opps < 0) {
+		dev_err(thermal->dev, "fail to get pm opp count, ret = %d\n", num_opps);
+		return num_opps;
+	}
+	if (num_opps == 0) {
+		dev_err(thermal->dev, "no OPP entries found\n");
+		return -ENODEV;
+	}
+
+	thermal->freq_table = kcalloc(num_opps, sizeof(*thermal->freq_table), GFP_KERNEL);
+	if (!thermal->freq_table)
+		goto error;
+
+	for (i = 0, freq = ULONG_MAX; i < num_opps; i++, freq--) {
+		struct dev_pm_opp *opp;
+
+		opp = dev_pm_opp_find_freq_floor(thermal->dev, &freq);
+		if (IS_ERR(opp))
+			break;
+
+		dev_pm_opp_put(opp);
+
+		dev_dbg(thermal->dev, "[%d] = %lu\n", i, freq);
+		if (freq < 100 * HZ_PER_MHZ)
+			break;
+
+		thermal->freq_table[i] = freq;
+		thermal->thermal_max = i;
+	}
+
+	if (!thermal->thermal_max)
+		goto error;
+
+	thermal->thermal_event = 0;
+	thermal->cooling = thermal_of_cooling_device_register(thermal->dev->of_node,
+							      dev_name(thermal->dev),
+							      thermal,
+							      &wave6_cooling_ops);
+	if (IS_ERR(thermal->cooling)) {
+		dev_err(thermal->dev, "register cooling device failed\n");
+		goto error;
+	}
+
+	return 0;
+
+error:
+	wave6_vpu_cooling_remove(thermal);
+
+	return -EINVAL;
+}
+
+void wave6_vpu_cooling_remove(struct vpu_thermal_cooling *thermal)
+{
+	thermal_cooling_device_unregister(thermal->cooling);
+	kfree(thermal->freq_table);
+	thermal->freq_table = NULL;
+}
diff --git a/drivers/media/platform/chips-media/wave6/wave6-vpu-thermal.h b/drivers/media/platform/chips-media/wave6/wave6-vpu-thermal.h
new file mode 100644
index 000000000000..16e86e99540a
--- /dev/null
+++ b/drivers/media/platform/chips-media/wave6/wave6-vpu-thermal.h
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) */
+/*
+ * Wave6 series multi-standard codec IP - wave6 thermal cooling interface
+ *
+ * Copyright (C) 2025 CHIPS&MEDIA INC
+ *
+ */
+
+#ifndef __WAVE6_VPU_THERMAL_H__
+#define __WAVE6_VPU_THERMAL_H__
+
+#include <linux/thermal.h>
+
+struct vpu_thermal_cooling {
+	struct device *dev;
+	struct device_node *of_node;
+	int thermal_event;
+	int thermal_max;
+	struct thermal_cooling_device *cooling;
+	unsigned long *freq_table;
+};
+
+int wave6_vpu_cooling_init(struct vpu_thermal_cooling *thermal);
+void wave6_vpu_cooling_remove(struct vpu_thermal_cooling *thermal);
+
+#endif /* __WAVE6_VPU_THERMAL_H__ */
-- 
2.31.1