new file mode 100644
@@ -0,0 +1,17 @@
+* Tango Thermal
+
+The SMP8758 SoC includes 3 instances of this temperature sensor
+(in the CPU, video decoder, and PCIe controller).
+
+Required properties:
+- #thermal-sensor-cells: Should be 0 (see thermal.txt)
+- compatible: "sigma,smp8758-thermal"
+- reg: Address range of the thermal registers
+
+Example:
+
+ cpu_temp: thermal@920100 {
+ #thermal-sensor-cells = <0>;
+ compatible = "sigma,smp8758-thermal";
+ reg = <0x920100 12>;
+ };
@@ -260,6 +260,15 @@ config ARMADA_THERMAL
Enable this option if you want to have support for thermal management
controller present in Armada 370 and Armada XP SoC.
+config TANGO_THERMAL
+ tristate "Tango thermal management"
+ depends on ARCH_TANGO || COMPILE_TEST
+ help
+ Enable the Tango thermal driver, which supports the primitive
+ temperature sensor embedded in Tango chips since the SMP8758.
+ This sensor only generates a 1-bit signal to indicate whether
+ the die temperature exceeds a programmable threshold.
+
config TEGRA_SOCTHERM
tristate "Tegra SOCTHERM thermal management"
depends on ARCH_TEGRA
@@ -35,6 +35,7 @@ obj-y += samsung/
obj-$(CONFIG_DOVE_THERMAL) += dove_thermal.o
obj-$(CONFIG_DB8500_THERMAL) += db8500_thermal.o
obj-$(CONFIG_ARMADA_THERMAL) += armada_thermal.o
+obj-$(CONFIG_TANGO_THERMAL) += tango_thermal.o
obj-$(CONFIG_IMX_THERMAL) += imx_thermal.o
obj-$(CONFIG_DB8500_CPUFREQ_COOLING) += db8500_cpufreq_cooling.o
obj-$(CONFIG_INTEL_POWERCLAMP) += intel_powerclamp.o
new file mode 100644
@@ -0,0 +1,125 @@
+#include <linux/io.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/thermal.h>
+#include <linux/platform_device.h>
+
+/*
+ * According to a data sheet draft, "this temperature sensor uses a bandgap
+ * type of circuit to compare a voltage which has a negative temperature
+ * coefficient with a voltage that is proportional to absolute temperature.
+ * A resistor bank allows 41 different temperature thresholds to be selected
+ * and the logic output will then indicate whether the actual die temperature
+ * lies above or below the selected threshold."
+ */
+
+#define TEMPSI_CMD 0
+#define TEMPSI_RES 4
+#define TEMPSI_CFG 8
+
+#define CMD_OFF 0
+#define CMD_ON 1
+#define CMD_READ 2
+
+#define IDX_MIN 15
+#define IDX_MAX 40
+#define CYCLE_COUNT 1000 /* Result sampled when timer expires */
+
+struct tango_thermal_priv {
+ struct thermal_zone_device *zone;
+ void __iomem *base;
+ int thresh_idx;
+};
+
+static bool temp_above_thresh(void __iomem *base, int thresh_idx)
+{
+ writel(CMD_READ | thresh_idx << 8, base + TEMPSI_CMD);
+ usleep_range(10, 20);
+ return readl(base + TEMPSI_RES);
+}
+
+static int tango_get_temp(void *arg, int *res)
+{
+ struct tango_thermal_priv *priv = arg;
+ void __iomem *base = priv->base;
+ int idx = priv->thresh_idx;
+
+ if (temp_above_thresh(base, idx)) {
+ /* Search upward by incrementing thresh_idx */
+ while (idx < IDX_MAX && temp_above_thresh(base, ++idx))
+ cpu_relax();
+ idx = idx - 1; /* always return lower bound */
+ } else {
+ /* Search downward by decrementing thresh_idx */
+ while (idx > IDX_MIN && !temp_above_thresh(base, --idx))
+ cpu_relax();
+ }
+
+ *res = (idx * 9 / 2 - 38) * 1000; /* millidegrees Celsius */
+ priv->thresh_idx = idx;
+
+ return 0;
+}
+
+static const struct thermal_zone_of_device_ops ops = {
+ .get_temp = tango_get_temp,
+};
+
+static int tango_thermal_probe(struct platform_device *pdev)
+{
+ struct resource *res;
+ struct tango_thermal_priv *priv;
+
+ priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ priv->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(priv->base))
+ return PTR_ERR(priv->base);
+
+ writel(CMD_ON, priv->base + TEMPSI_CMD);
+ writel(CYCLE_COUNT, priv->base + TEMPSI_CFG);
+
+ priv->zone = thermal_zone_of_sensor_register(&pdev->dev, 0, priv, &ops);
+ if (IS_ERR(priv->zone))
+ return PTR_ERR(priv->zone);
+
+ priv->thresh_idx = IDX_MIN;
+ platform_set_drvdata(pdev, priv);
+
+ return 0;
+}
+
+static int tango_thermal_remove(struct platform_device *pdev)
+{
+ struct tango_thermal_priv *priv = platform_get_drvdata(pdev);
+
+ thermal_zone_of_sensor_unregister(&pdev->dev, priv->zone);
+ writel(CMD_OFF, priv->base + TEMPSI_CMD);
+
+ return 0;
+}
+
+static const struct of_device_id tango_sensor_ids[] = {
+ {
+ .compatible = "sigma,smp8758-thermal",
+ },
+ { /* sentinel */ }
+};
+
+static struct platform_driver tango_thermal_driver = {
+ .probe = tango_thermal_probe,
+ .remove = tango_thermal_remove,
+ .driver = {
+ .name = "tango-thermal",
+ .of_match_table = tango_sensor_ids,
+ },
+};
+
+module_platform_driver(tango_thermal_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Sigma Designs");
+MODULE_DESCRIPTION("Tango temperature sensor");