linux-kernel - Re: [PATCH 2/3] thermal: qoriq_thermal: only enable supported sensors

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Message-ID: <3e397cf5-0ca3-fa10-b5d8-bbc7b1038a37@linaro.org>
Date:   Thu, 15 Jun 2023 13:48:49 +0200
From:   Daniel Lezcano <daniel.lezcano@...aro.org>
To:     Peng Fan <peng.fan@....nxp.com>,
        Sebastian Krzyszkowiak <sebastian.krzyszkowiak@...i.sm>,
        Peng Fan <peng.fan@....com>,
        "rafael@...nel.org" <rafael@...nel.org>,
        "shawnguo@...nel.org" <shawnguo@...nel.org>,
        "s.hauer@...gutronix.de" <s.hauer@...gutronix.de>
Cc:     "amitk@...nel.org" <amitk@...nel.org>,
        "rui.zhang@...el.com" <rui.zhang@...el.com>,
        "andrew.smirnov@...il.com" <andrew.smirnov@...il.com>,
        "linux-pm@...r.kernel.org" <linux-pm@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "kernel@...gutronix.de" <kernel@...gutronix.de>,
        "festevam@...il.com" <festevam@...il.com>,
        dl-linux-imx <linux-imx@....com>,
        "linux-arm-kernel@...ts.infradead.org" 
        <linux-arm-kernel@...ts.infradead.org>,
        Alice Guo <alice.guo@....com>
Subject: Re: [PATCH 2/3] thermal: qoriq_thermal: only enable supported sensors

On 15/06/2023 06:04, Peng Fan wrote:
> 
> 
> On 6/15/2023 10:53 AM, Sebastian Krzyszkowiak wrote:
>> Caution: This is an external email. Please take care when clicking 
>> links or opening attachments. When in doubt, report the message using 
>> the 'Report this email' button
>>
>>
>> On czwartek, 15 czerwca 2023 04:29:01 CEST Peng Fan wrote:
>>> On 6/8/2023 3:10 AM, Daniel Lezcano wrote:
>>>>
>>>> [...]
>>>>
>>>> Ok, I misunderstood. I thought that was for failing registered thermal
>>>> zone.
>>>>
>>>> Would enabling the site in ops->change_mode do the trick ?
>>>
>>> No. ops->change_mode not able to do the trick.
>>>
>>> devm_thermal_of_zone_register->thermal_zone_device_enable
>>> ->thermal_zone_device_set_mode->__thermal_zone_device_update.part.0
>>> ->__thermal_zone_get_temp
>>>
>>> The thermal_zone_device_set_mode will call change_mode, if return
>>> fail here, the thermal zone will fail to be registered.
>>>
>>> Thanks,
>>> Peng.
>>
>> I think the idea is not to return a failure in ops->change_mode, but 
>> to move
>> enabling the site in REGS_TMR/REGS_V2_TMSR register from
>> qoriq_tmu_register_tmu_zone to ops->change_mode. 
> 
> But qoriq_tmu_register_tmu_zone will finally call ops->change_mode.
> 
> And it is per zone, so we not able to enable TMR_ME here.
> 
> This way the site will be
>> enabled only for actually existing thermal zones, since those not 
>> described in
>> the device tree won't reach thermal_zone_device_enable.
> 
> No. The TMR_ME is the gate for all sites.

What about the following change on top of your series:

diff --git a/drivers/thermal/qoriq_thermal.c 
b/drivers/thermal/qoriq_thermal.c
index c710449b0c50..ecf88bf13762 100644
--- a/drivers/thermal/qoriq_thermal.c
+++ b/drivers/thermal/qoriq_thermal.c
@@ -107,8 +107,6 @@ static int tmu_get_temp(struct thermal_zone_device 
*tz, int *temp)
  	 */

  	regmap_read(qdata->regmap, REGS_TMR, &val);
-	if (!(val & TMR_ME))
-		return -EAGAIN;

  	if (regmap_read_poll_timeout(qdata->regmap,
  				     REGS_TRITSR(qsensor->id),
@@ -131,14 +129,40 @@ static int tmu_get_temp(struct thermal_zone_device 
*tz, int *temp)
  	return 0;
  }

+static int qoriq_tmu_change_mode(struct thermal_zone_device *tz,
+				 enum thermal_device_mode mode)
+{
+	struct qoriq_sensor *qsensor = thermal_zone_device_priv(tz);
+	struct qoriq_tmu_data *qdata = qoriq_sensor_to_data(qsensor);
+	unsigned int site;
+	unsigned int value;
+	unsigned int mask;
+
+	if (qdata->ver == TMU_VER1) {
+		site = BIT(15 - qsensor->id);
+		mask = TMR_ME | TMR_ALPF | site;
+		value = mode == THERMAL_DEVICE_ENABLED ? mask : mask & ~site;
+		regmap_update_bits(qdata->regmap, REGS_TMR, mask, value);
+	} else {
+		site = BIT(qsensor->id);
+		mask = TMR_ME | TMR_ALPF_V2 | site;
+		value = mode == THERMAL_DEVICE_ENABLED ? mask : mask & ~site;
+		regmap_update_bits(qdata->regmap, REGS_V2_TMSR, mask, value);
+		regmap_write(qdata->regmap, REGS_TMR, TMR_ME | TMR_ALPF_V2);
+	}
+
+	return 0;
+}
+
  static const struct thermal_zone_device_ops tmu_tz_ops = {
  	.get_temp = tmu_get_temp,
+	.change_mode = qoriq_tmu_change_mode,
  };

  static int qoriq_tmu_register_tmu_zone(struct device *dev,
  				       struct qoriq_tmu_data *qdata)
  {
-	int id, sites = 0;
+	int id;

  	for (id = 0; id < SITES_MAX; id++) {
  		struct thermal_zone_device *tzd;
@@ -158,25 +182,11 @@ static int qoriq_tmu_register_tmu_zone(struct 
device *dev,
  			return ret;
  		}

-		if (qdata->ver == TMU_VER1)
-			sites |= 0x1 << (15 - id);
-		else
-			sites |= 0x1 << id;
-
  		if (devm_thermal_add_hwmon_sysfs(dev, tzd))
  			dev_warn(dev,
  				 "Failed to add hwmon sysfs attributes\n");
  	}

-	if (sites) {
-		if (qdata->ver == TMU_VER1) {
-			regmap_write(qdata->regmap, REGS_TMR, TMR_ME | TMR_ALPF | sites);
-		} else {
-			regmap_write(qdata->regmap, REGS_V2_TMSR, sites);
-			regmap_write(qdata->regmap, REGS_TMR, TMR_ME | TMR_ALPF_V2);
-		}
-	}
-
  	return 0;
  }


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