On 19/02/20 1:20 pm, Randy Dunlap wrote:

On 2/18/20 11:43 PM, Keerthy wrote:

quoted

The bandgap provides current and voltage reference for its internal
circuits and other analog IP blocks. The analog-to-digital
converter (ADC) produces an output value that is proportional
to the silicon temperature.

Currently reading temperatures and trend computing is supported
as there are no active/passive cooling agent supported.

Signed-off-by: Keerthy <j-keerthy@ti.com>
---
  drivers/thermal/Kconfig      |  12 ++
  drivers/thermal/Makefile     |   1 +
  drivers/thermal/k3_bandgap.c | 342 +++++++++++++++++++++++++++++++++++
  3 files changed, 355 insertions(+)
  create mode 100644 drivers/thermal/k3_bandgap.c

diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index 5a05db5438d6..fa598eddc7ac 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig

@@ -251,6 +251,18 @@ config IMX_THERMAL
  	  cpufreq is used as the cooling device to throttle CPUs when the
  	  passive trip is crossed.
  
+config K3_THERMAL
+	bool "Texas Instruments K3 thermal support"

Hi,
Why is this bool and not tristate?

Definitely can work as tristate. I will fix it next version.

quoted

+	depends on THERMAL
+	depends on ARCH_K3 || COMPILE_TEST
+	help
+	  If you say yes here you get thermal support for the Texas Instruments
+	  K3 SoC family. The current chip supported is:
+	   - AM654
+
+	  This includes temperature reading functionality and also trend
+	  computation.
+
  config MAX77620_THERMAL
  	tristate "Temperature sensor driver for Maxim MAX77620 PMIC"
  	depends on MFD_MAX77620

quoted

diff --git a/drivers/thermal/k3_bandgap.c b/drivers/thermal/k3_bandgap.c
new file mode 100644
index 000000000000..35d904eb9857
--- /dev/null
+++ b/drivers/thermal/k3_bandgap.c

@@ -0,0 +1,342 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * TI Bandgap temperature sensor driver for K3 SoC Family
+ *
+ * Copyright (C) 2020 Texas Instruments Incorporated - http://www.ti.com/
+ */

quoted

+static int k3_bgp_read_temp(struct k3_thermal_data *devdata,
+			    int *temp)
+{
+	struct k3_bandgap *bgp;
+	unsigned int dtemp, s0, s1, s2;
+
+	bgp = devdata->bgp;
+	/**

"/**" is used to indicate kernel-doc notation in the Linux kernel source files,
but this comment is not kernel-doc notation, so please just use "/*".

Okay

quoted

+	 * Errata is applicable for am654 pg 1.0 silicon. There
+	 * is a variation of the order for 8-10 degree centigrade.
+	 * Work around that by getting the average of two closest
+	 * readings out of three readings everytime we want to
+	 * report temperatures.
+	 *
+	 * Errata workaround.
+	 */

thanks.

Thanks for the review.

- Keerthy

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