[PATCH 4/8] thermal: amlogic: Add support for secure monitor calibration readout

[Ronald Claveau]

Some SoCs (e.g. T7) expose thermal calibration data through the secure
monitor rather than a directly accessible eFuse register. Add a use_sm
flag to amlogic_thermal_data to select this path, and retrieve the
firmware handle and tsensor_id from the "amlogic,secure-monitor" DT
phandle with one fixed argument.

Also introduce the amlogic,t7-thermal compatible using this new path.

Signed-off-by: Ronald Claveau <linux-kernel-dev at aliel.fr>
---
 drivers/thermal/amlogic_thermal.c | 58 +++++++++++++++++++++++++++++++++++----
 1 file changed, 53 insertions(+), 5 deletions(-)

diff --git a/drivers/thermal/amlogic_thermal.c b/drivers/thermal/amlogic_thermal.c
index 5448d772db12a..11e3948cc0669 100644
--- a/drivers/thermal/amlogic_thermal.c
+++ b/drivers/thermal/amlogic_thermal.c
@@ -25,6 +25,7 @@
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
 #include <linux/thermal.h>
+#include <linux/firmware/meson/meson_sm.h>
 
 #include "thermal_hwmon.h"
 
@@ -84,12 +85,14 @@ struct amlogic_thermal_soc_calib_data {
  * @u_efuse_off: register offset to read fused calibration value
  * @calibration_parameters: calibration parameters structure pointer
  * @regmap_config: regmap config for the device
+ * @use_sm: read data from secure monitor instead of efuse
  * This structure is required for configuration of amlogic thermal driver.
  */
 struct amlogic_thermal_data {
 	int u_efuse_off;
 	const struct amlogic_thermal_soc_calib_data *calibration_parameters;
 	const struct regmap_config *regmap_config;
+	bool use_sm;
 };
 
 struct amlogic_thermal {
@@ -100,6 +103,8 @@ struct amlogic_thermal {
 	struct clk *clk;
 	struct thermal_zone_device *tzd;
 	u32 trim_info;
+	struct meson_sm_firmware *sm_fw;
+	u32 tsensor_id;
 };
 
 /*
@@ -138,6 +143,12 @@ static int amlogic_thermal_initialize(struct amlogic_thermal *pdata)
 	int ret = 0;
 	int ver;
 
+	if (pdata->data->use_sm) {
+		return meson_sm_get_thermal_calib(pdata->sm_fw,
+						  &pdata->trim_info,
+						  pdata->tsensor_id);
+	}
+
 	regmap_read(pdata->sec_ao_map, pdata->data->u_efuse_off,
 		    &pdata->trim_info);
 
@@ -226,6 +237,12 @@ static const struct amlogic_thermal_data amlogic_thermal_a1_cpu_param = {
 	.regmap_config = &amlogic_thermal_regmap_config_g12a,
 };
 
+static const struct amlogic_thermal_data amlogic_thermal_t7_param = {
+	.use_sm			= true,
+	.calibration_parameters	= &amlogic_thermal_g12a,
+	.regmap_config		= &amlogic_thermal_regmap_config_g12a,
+};
+
 static const struct of_device_id of_amlogic_thermal_match[] = {
 	{
 		.compatible = "amlogic,g12a-ddr-thermal",
@@ -239,6 +256,10 @@ static const struct of_device_id of_amlogic_thermal_match[] = {
 		.compatible = "amlogic,a1-cpu-thermal",
 		.data = &amlogic_thermal_a1_cpu_param,
 	},
+	{
+		.compatible = "amlogic,t7-thermal",
+		.data = &amlogic_thermal_t7_param,
+	},
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, of_amlogic_thermal_match);
@@ -271,11 +292,38 @@ static int amlogic_thermal_probe(struct platform_device *pdev)
 	if (IS_ERR(pdata->clk))
 		return dev_err_probe(dev, PTR_ERR(pdata->clk), "failed to get clock\n");
 
-	pdata->sec_ao_map = syscon_regmap_lookup_by_phandle
-		(pdev->dev.of_node, "amlogic,ao-secure");
-	if (IS_ERR(pdata->sec_ao_map)) {
-		dev_err(dev, "syscon regmap lookup failed.\n");
-		return PTR_ERR(pdata->sec_ao_map);
+	if (pdata->data->use_sm) {
+		struct device_node *sm_np;
+		struct of_phandle_args ph_args;
+
+		ret = of_parse_phandle_with_fixed_args(pdev->dev.of_node,
+						       "amlogic,secure-monitor",
+						       1, 0, &ph_args);
+		if (ret)
+			return ret;
+
+		sm_np = ph_args.np;
+		if (!sm_np) {
+			dev_err(dev,
+				"Failed to parse secure monitor phandle\n");
+			return -ENODEV;
+		}
+
+		pdata->sm_fw = meson_sm_get(sm_np);
+		of_node_put(sm_np);
+		if (!pdata->sm_fw) {
+			dev_err(dev, "Failed to get secure monitor firmware\n");
+			return -EPROBE_DEFER;
+		}
+
+		pdata->tsensor_id = ph_args.args[0];
+	} else {
+		pdata->sec_ao_map = syscon_regmap_lookup_by_phandle
+			(pdev->dev.of_node, "amlogic,ao-secure");
+		if (IS_ERR(pdata->sec_ao_map)) {
+			dev_err(dev, "syscon regmap lookup failed.\n");
+			return PTR_ERR(pdata->sec_ao_map);
+		}
 	}
 
 	pdata->tzd = devm_thermal_of_zone_register(&pdev->dev,

-- 
2.49.0