On 31/07/2025 19:19, John Madieu wrote:
Hi Daniel,
Thanks for your review.
-----Original Message-----
From: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
Sent: Wednesday, July 16, 2025 11:11 PM
To: John Madieu <john.madieu.xa@xxxxxxxxxxxxxx>
Subject: Re: [PATCH v6 3/5] thermal: renesas: rzg3e: Add thermal driver
for the Renesas RZ/G3E SoC
On Thu, May 22, 2025 at 08:22:46PM +0200, John Madieu wrote:
The RZ/G3E SoC integrates a Temperature Sensor Unit (TSU) block
designed to monitor the chip's junction temperature. This sensor is
connected to channel 1 of the APB port clock/reset and provides
temperature measurements.
It also requires calibration values stored in the system controller
registers for accurate temperature measurement. Add a driver for the
Renesas RZ/G3E TSU.
Signed-off-by: John Madieu <john.madieu.xa@xxxxxxxxxxxxxx>
---
[ ... ]
+static int rzg3e_thermal_get_temp(struct thermal_zone_device *zone,
+int *temp) {
+ struct rzg3e_thermal_priv *priv = thermal_zone_device_priv(zone);
+ u32 val;
+ int ret;
+
+ if (priv->mode == THERMAL_DEVICE_DISABLED)
+ return -EBUSY;
[ ... ]
+ reinit_completion(&priv->conv_complete);
+
+ /* Enable ADC interrupt */
+ writel(TSU_SIER_ADIE, priv->base + TSU_SIER);
Why enable irq here ?
I did it this way because, in 'set_trips' callback, the
driver does trigger conversion to check whether the current
temperature is part of the window or not, and triggers the
comparison interrupt accordingly. Because of that, I did not
want the conversion-complete interrupt to also be triggered.
That's the reason why I enable conversion-complete interrupt
in 'get_temp', to make sure its interrupt is being triggered
only when the thermal core calls it.
Should I do it another way ?
I don't ATM, the approach is very unusual so I'm still trying to figure
out what is this completion approach and readl_poll_timeout_atomic. At
the first glance I would say it is wrong.
+ /* Verify no ongoing conversion */
+ ret = readl_poll_timeout_atomic(priv->base + TSU_SSR, val,
+ !(val & TSU_SSR_CONV_RUNNING),
+ TSU_POLL_DELAY_US, TSU_TIMEOUT_US);
+ if (ret) {
+ dev_err(priv->dev, "ADC conversion timed out\n");
+ return ret;
+ }
+
+ /* Start conversion */
+ writel(TSU_STRGR_ADST, priv->base + TSU_STRGR);
+
+ if (!wait_for_completion_timeout(&priv->conv_complete,
+ msecs_to_jiffies(100))) {
+ dev_err(priv->dev, "ADC conversion completion timeout\n");
+ return -ETIMEDOUT;
+ }
Can you explain what is happening here ?
I might not get what you are asking, but since I compute the
temperature in the hard IRQ handler, I just wait for it to complete
and notify the completion so I can grab the processed value to notify
the thermal core.
Please let me know if this does not answer your question.
Can you describe how the sensor works ? And perhaps if you have a
pointer to some documentation ?
[ ... ]
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