Re: [PATCH v5 3/9] remoteproc: qcom: pas: add support for TMD thermal cooling devices

[Gaurav Kohli <gaurav.kohli@oss.qualcomm.com>]

On 7/22/2026 4:37 AM, Dmitry Baryshkov wrote:
> On Tue, Jul 21, 2026 at 11:59:00AM +0530, Gaurav Kohli wrote:
>> Register Thermal Mitigation Devices (TMDs) for PAS-managed remote
>> processors to enable thermal throttling through QMI.
>>
>> This allows the thermal framework to request mitigation when remote
>> subsystems such as modem and CDSP contribute to thermal pressure.
>>
>> Signed-off-by: Gaurav Kohli <gaurav.kohli@oss.qualcomm.com>
>> ---
>>   drivers/remoteproc/Kconfig         |  1 +
>>   drivers/remoteproc/qcom_q6v5_pas.c | 90 +++++++++++++++++++++++++++++++++++++-
>>   2 files changed, 90 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig
>> index 65befdbfa5f7..f7c02edf395f 100644
>> --- a/drivers/remoteproc/Kconfig
>> +++ b/drivers/remoteproc/Kconfig
>> @@ -229,6 +229,7 @@ config QCOM_Q6V5_PAS
>>   	select QCOM_PIL_INFO
>>   	select QCOM_MDT_LOADER
>>   	select QCOM_Q6V5_COMMON
>> +	select QCOM_QMI_TMD
> 
> Sashiko warned here about the missing NET dependencies.

thanks for review, will fix this.
> 
>>   	select QCOM_RPROC_COMMON
>>   	select QCOM_SCM
>>   	select QCOM_PAS
>> diff --git a/drivers/remoteproc/qcom_q6v5_pas.c b/drivers/remoteproc/qcom_q6v5_pas.c
>> index 25599d728208..dc5be2c030cf 100644
>> --- a/drivers/remoteproc/qcom_q6v5_pas.c
>> +++ b/drivers/remoteproc/qcom_q6v5_pas.c
>> @@ -5,6 +5,7 @@
>>    * Copyright (C) 2016 Linaro Ltd
>>    * Copyright (C) 2014 Sony Mobile Communications AB
>>    * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
>> + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
>>    */
>>   
>>   #include <linux/clk.h>
>> @@ -26,8 +27,10 @@
>>   #include <linux/regulator/consumer.h>
>>   #include <linux/remoteproc.h>
>>   #include <linux/soc/qcom/mdt_loader.h>
>> +#include <linux/soc/qcom/qmi_tmd.h>
>>   #include <linux/soc/qcom/smem.h>
>>   #include <linux/soc/qcom/smem_state.h>
>> +#include <dt-bindings/thermal/qcom,qmi-tmd.h>
>>   
>>   #include "qcom_common.h"
>>   #include "qcom_pil_info.h"
>> @@ -38,6 +41,16 @@
>>   
>>   #define MAX_ASSIGN_COUNT 3
>>   
>> +/**
>> + * struct tmd_name - TMD device name to cooling-device index mapping
>> + * @name: TMD device name
>> + * @id: Cooling-device index used as #cooling-cells cell 0 in DT
>> + */
>> +struct tmd_name {
>> +	const char *name;
>> +	int id;
>> +};
>> +
>>   struct qcom_pas_data {
>>   	int crash_reason_smem;
>>   	const char *firmware_name;
>> @@ -58,6 +71,10 @@ struct qcom_pas_data {
>>   	int ssctl_id;
>>   	unsigned int smem_host_id;
>>   
>> +	unsigned int tmd_instance_id;
>> +	const struct tmd_name *tmd_name;
>> +	int num_tmd;
>> +
>>   	int region_assign_idx;
>>   	int region_assign_count;
>>   	bool region_assign_shared;
>> @@ -122,6 +139,8 @@ struct qcom_pas {
>>   
>>   	struct qcom_pas_context *pas_ctx;
>>   	struct qcom_pas_context *dtb_pas_ctx;
>> +
>> +	struct qmi_tmd_client *tmd_inst;
>>   };
>>   
>>   static void qcom_pas_segment_dump(struct rproc *rproc,
>> @@ -798,6 +817,64 @@ static void qcom_pas_unassign_memory_region(struct qcom_pas *pas)
>>   	}
>>   }
>>   
>> +static int qcom_pas_setup_tmd(struct qcom_pas *pas, const struct qcom_pas_data *desc)
>> +{
>> +	struct qmi_tmd_client *tmd_inst;
>> +	const struct tmd_name *tmd;
>> +	const char **tmd_names;
>> +	int i, ret;
>> +
>> +	if (!device_property_present(pas->dev, "#cooling-cells"))
>> +		return 0;
>> +
>> +	if (!desc->tmd_name || desc->num_tmd == 0)
>> +		return 0;
>> +
>> +	tmd_names = devm_kcalloc(pas->dev, desc->num_tmd,
>> +				 sizeof(*tmd_names), GFP_KERNEL);
>> +	if (!tmd_names)
>> +		return -ENOMEM;
>> +
>> +	for (i = 0; i < desc->num_tmd; i++) {
>> +		tmd = &desc->tmd_name[i];
>> +
>> +		if (tmd->id < 0 || tmd->id >= desc->num_tmd) {
> 
> The < 0 check is totally redundant.

Ack, this is redundant only.
> 
> For the second check, currently the driver will set num_tmd to
> ARRAY_SIZE(desc->tmds), which makes second part either redundant or
> invalid. I assume that here you want to compare to some maximum TMD
> number to be supported rather than a fixed ARRAY_SIZE().

This is just a defensive check to prevent mistakes in the static mapping
table. The current mappings use dense IDs starting from 0, so
desc->num_tmd matches the valid ID range today.

> 
>> +			dev_err(pas->dev, "Invalid TMD id %d for '%s'\n",
>> +				tmd->id, tmd->name);
>> +			return -EINVAL;
>> +		}
>> +
>> +		if (tmd_names[tmd->id]) {
>> +			dev_err(pas->dev, "Duplicate TMD id %d for '%s'\n",
>> +				tmd->id, tmd->name);
>> +			return -EINVAL;
>> +		}
>> +
>> +		tmd_names[tmd->id] = tmd->name;
>> +	}
>> +
>> +	for (i = 0; i < desc->num_tmd; i++) {
>> +		if (!tmd_names[i]) {
>> +			dev_err(pas->dev, "Missing TMD mapping for id %d\n", i);
>> +			return -EINVAL;
>> +		}
>> +	}
>> +
>> +	tmd_inst = qmi_tmd_init(pas->dev, desc->tmd_instance_id, tmd_names,
>> +				desc->num_tmd);
> 
> And this makes it even more strange. Can there be holes in the
> tmd_names? Can platform omit some of the TMDs? Assumingly yes, this
> is not correct (nor is devm_kcalloc).

thanks for review.
For example, if the static table contains:

   tmd1 -> id 0
   tmd2 -> id 1
   tmd3 -> id 2

but firmware reports only tmd1 and tmd3, then cooling devices are
registered only for IDs 0 and 2. No cooling device is registered for
tmd2, so the corresponding DT cooling-device binding will not happen.

The devm_kcalloc() is still needed because qmi_tmd_init() expects an
indexed name array matching the DT cooling-device IDs. The current 
static mapping assumes those IDs are dense, so there are no holes in the 
mapping array itself.

> 
>> +	if (IS_ERR(tmd_inst)) {
>> +		ret = PTR_ERR(tmd_inst);
>> +		if (ret == -ENODEV)
>> +			return 0;
>> +
>> +		return ret;
>> +	}
>> +
>> +	pas->tmd_inst = tmd_inst;
>> +
>> +	return 0;
>> +}
>> +
>>   static int qcom_pas_probe(struct platform_device *pdev)
>>   {
>>   	const struct qcom_pas_data *desc;
>> @@ -925,16 +1002,24 @@ static int qcom_pas_probe(struct platform_device *pdev)
>>   	if (desc->early_boot)
>>   		pas->rproc->state = RPROC_DETACHED;
>>   
>> -	ret = rproc_add(rproc);
>> +	ret = qcom_pas_setup_tmd(pas, desc);
>>   	if (ret)
>>   		goto remove_ssr_sysmon;
>>   
>> +	ret = rproc_add(rproc);
>> +	if (ret)
>> +		goto remove_setup_tmd;
>> +
>>   	node = of_get_compatible_child(pdev->dev.of_node, "qcom,bam-dmux");
>>   	pas->bam_dmux = of_platform_device_create(node, NULL, &pdev->dev);
>>   	of_node_put(node);
>>   
>>   	return 0;
>>   
>> +remove_setup_tmd:
>> +	if (pas->tmd_inst)
>> +		qmi_tmd_exit(pas->tmd_inst);
>> +
>>   remove_ssr_sysmon:
>>   	qcom_remove_ssr_subdev(rproc, &pas->ssr_subdev);
>>   	qcom_remove_sysmon_subdev(pas->sysmon);
>> @@ -960,6 +1045,9 @@ static void qcom_pas_remove(struct platform_device *pdev)
>>   	if (pas->bam_dmux)
>>   		of_platform_device_destroy(&pas->bam_dmux->dev, NULL);
>>   
>> +	if (pas->tmd_inst)
>> +		qmi_tmd_exit(pas->tmd_inst);
>> +
>>   	rproc_del(pas->rproc);
>>   
>>   	qcom_q6v5_deinit(&pas->q6v5);
>>
>> -- 
>> 2.34.1
>>
>