1 files changed, 387 insertions, 0 deletions
diff --git a/drivers/thermal/broadcom/brcmstb_thermal.c b/drivers/thermal/broadcom/brcmstb_thermal.c
new file mode 100644
index 000000000000..1919f91fa756
--- /dev/null
+++ b/drivers/thermal/broadcom/brcmstb_thermal.c
@@ -0,0 +1,387 @@
+/*
+ * Broadcom STB AVS TMON thermal sensor driver
+ *
+ * Copyright (c) 2015-2017 Broadcom
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#define DRV_NAME	"brcmstb_thermal"
+
+#define pr_fmt(fmt)	DRV_NAME ": " fmt
+
+#include <linux/bitops.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/irqreturn.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/of_device.h>
+#include <linux/thermal.h>
+
+#define AVS_TMON_STATUS			0x00
+ #define AVS_TMON_STATUS_valid_msk	BIT(11)
+ #define AVS_TMON_STATUS_data_msk	GENMASK(10, 1)
+ #define AVS_TMON_STATUS_data_shift	1
+
+#define AVS_TMON_EN_OVERTEMP_RESET	0x04
+ #define AVS_TMON_EN_OVERTEMP_RESET_msk	BIT(0)
+
+#define AVS_TMON_RESET_THRESH		0x08
+ #define AVS_TMON_RESET_THRESH_msk	GENMASK(10, 1)
+ #define AVS_TMON_RESET_THRESH_shift	1
+
+#define AVS_TMON_INT_IDLE_TIME		0x10
+
+#define AVS_TMON_EN_TEMP_INT_SRCS	0x14
+ #define AVS_TMON_EN_TEMP_INT_SRCS_high	BIT(1)
+ #define AVS_TMON_EN_TEMP_INT_SRCS_low	BIT(0)
+
+#define AVS_TMON_INT_THRESH		0x18
+ #define AVS_TMON_INT_THRESH_high_msk	GENMASK(26, 17)
+ #define AVS_TMON_INT_THRESH_high_shift	17
+ #define AVS_TMON_INT_THRESH_low_msk	GENMASK(10, 1)
+ #define AVS_TMON_INT_THRESH_low_shift	1
+
+#define AVS_TMON_TEMP_INT_CODE		0x1c
+#define AVS_TMON_TP_TEST_ENABLE		0x20
+
+/* Default coefficients */
+#define AVS_TMON_TEMP_SLOPE		-487
+#define AVS_TMON_TEMP_OFFSET		410040
+
+/* HW related temperature constants */
+#define AVS_TMON_TEMP_MAX		0x3ff
+#define AVS_TMON_TEMP_MIN		-88161
+#define AVS_TMON_TEMP_MASK		AVS_TMON_TEMP_MAX
+
+enum avs_tmon_trip_type {
+	TMON_TRIP_TYPE_LOW = 0,
+	TMON_TRIP_TYPE_HIGH,
+	TMON_TRIP_TYPE_RESET,
+	TMON_TRIP_TYPE_MAX,
+};
+
+struct avs_tmon_trip {
+	/* HW bit to enable the trip */
+	u32 enable_offs;
+	u32 enable_mask;
+
+	/* HW field to read the trip temperature */
+	u32 reg_offs;
+	u32 reg_msk;
+	int reg_shift;
+};
+
+static struct avs_tmon_trip avs_tmon_trips[] = {
+	/* Trips when temperature is below threshold */
+	[TMON_TRIP_TYPE_LOW] = {
+		.enable_offs	= AVS_TMON_EN_TEMP_INT_SRCS,
+		.enable_mask	= AVS_TMON_EN_TEMP_INT_SRCS_low,
+		.reg_offs	= AVS_TMON_INT_THRESH,
+		.reg_msk	= AVS_TMON_INT_THRESH_low_msk,
+		.reg_shift	= AVS_TMON_INT_THRESH_low_shift,
+	},
+	/* Trips when temperature is above threshold */
+	[TMON_TRIP_TYPE_HIGH] = {
+		.enable_offs	= AVS_TMON_EN_TEMP_INT_SRCS,
+		.enable_mask	= AVS_TMON_EN_TEMP_INT_SRCS_high,
+		.reg_offs	= AVS_TMON_INT_THRESH,
+		.reg_msk	= AVS_TMON_INT_THRESH_high_msk,
+		.reg_shift	= AVS_TMON_INT_THRESH_high_shift,
+	},
+	/* Automatically resets chip when above threshold */
+	[TMON_TRIP_TYPE_RESET] = {
+		.enable_offs	= AVS_TMON_EN_OVERTEMP_RESET,
+		.enable_mask	= AVS_TMON_EN_OVERTEMP_RESET_msk,
+		.reg_offs	= AVS_TMON_RESET_THRESH,
+		.reg_msk	= AVS_TMON_RESET_THRESH_msk,
+		.reg_shift	= AVS_TMON_RESET_THRESH_shift,
+	},
+};
+
+struct brcmstb_thermal_priv {
+	void __iomem *tmon_base;
+	struct device *dev;
+	struct thermal_zone_device *thermal;
+};
+
+static void avs_tmon_get_coeffs(struct thermal_zone_device *tz, int *slope,
+				int *offset)
+{
+	*slope = thermal_zone_get_slope(tz);
+	*offset = thermal_zone_get_offset(tz);
+}
+
+/* Convert a HW code to a temperature reading (millidegree celsius) */
+static inline int avs_tmon_code_to_temp(struct thermal_zone_device *tz,
+					u32 code)
+{
+	const int val = code & AVS_TMON_TEMP_MASK;
+	int slope, offset;
+
+	avs_tmon_get_coeffs(tz, &slope, &offset);
+
+	return slope * val + offset;
+}
+
+/*
+ * Convert a temperature value (millidegree celsius) to a HW code
+ *
+ * @temp: temperature to convert
+ * @low: if true, round toward the low side
+ */
+static inline u32 avs_tmon_temp_to_code(struct thermal_zone_device *tz,
+					int temp, bool low)
+{
+	int slope, offset;
+
+	if (temp < AVS_TMON_TEMP_MIN)
+		return AVS_TMON_TEMP_MAX; /* Maximum code value */
+
+	avs_tmon_get_coeffs(tz, &slope, &offset);
+
+	if (temp >= offset)
+		return 0;	/* Minimum code value */
+
+	if (low)
+		return (u32)(DIV_ROUND_UP(offset - temp, abs(slope)));
+	else
+		return (u32)((offset - temp) / abs(slope));
+}
+
+static int brcmstb_get_temp(void *data, int *temp)
+{
+	struct brcmstb_thermal_priv *priv = data;
+	u32 val;
+	long t;
+
+	val = __raw_readl(priv->tmon_base + AVS_TMON_STATUS);
+
+	if (!(val & AVS_TMON_STATUS_valid_msk)) {
+		dev_err(priv->dev, "reading not valid\n");
+		return -EIO;
+	}
+
+	val = (val & AVS_TMON_STATUS_data_msk) >> AVS_TMON_STATUS_data_shift;
+
+	t = avs_tmon_code_to_temp(priv->thermal, val);
+	if (t < 0)
+		*temp = 0;
+	else
+		*temp = t;
+
+	return 0;
+}
+
+static void avs_tmon_trip_enable(struct brcmstb_thermal_priv *priv,
+				 enum avs_tmon_trip_type type, int en)
+{
+	struct avs_tmon_trip *trip = &avs_tmon_trips[type];
+	u32 val = __raw_readl(priv->tmon_base + trip->enable_offs);
+
+	dev_dbg(priv->dev, "%sable trip, type %d\n", en ? "en" : "dis", type);
+
+	if (en)
+		val |= trip->enable_mask;
+	else
+		val &= ~trip->enable_mask;
+
+	__raw_writel(val, priv->tmon_base + trip->enable_offs);
+}
+
+static int avs_tmon_get_trip_temp(struct brcmstb_thermal_priv *priv,
+				  enum avs_tmon_trip_type type)
+{
+	struct avs_tmon_trip *trip = &avs_tmon_trips[type];
+	u32 val = __raw_readl(priv->tmon_base + trip->reg_offs);
+
+	val &= trip->reg_msk;
+	val >>= trip->reg_shift;
+
+	return avs_tmon_code_to_temp(priv->thermal, val);
+}
+
+static void avs_tmon_set_trip_temp(struct brcmstb_thermal_priv *priv,
+				   enum avs_tmon_trip_type type,
+				   int temp)
+{
+	struct avs_tmon_trip *trip = &avs_tmon_trips[type];
+	u32 val, orig;
+
+	dev_dbg(priv->dev, "set temp %d to %d\n", type, temp);
+
+	/* round toward low temp for the low interrupt */
+	val = avs_tmon_temp_to_code(priv->thermal, temp,
+				    type == TMON_TRIP_TYPE_LOW);
+
+	val <<= trip->reg_shift;
+	val &= trip->reg_msk;
+
+	orig = __raw_readl(priv->tmon_base + trip->reg_offs);
+	orig &= ~trip->reg_msk;
+	orig |= val;
+	__raw_writel(orig, priv->tmon_base + trip->reg_offs);
+}
+
+static int avs_tmon_get_intr_temp(struct brcmstb_thermal_priv *priv)
+{
+	u32 val;
+
+	val = __raw_readl(priv->tmon_base + AVS_TMON_TEMP_INT_CODE);
+	return avs_tmon_code_to_temp(priv->thermal, val);
+}
+
+static irqreturn_t brcmstb_tmon_irq_thread(int irq, void *data)
+{
+	struct brcmstb_thermal_priv *priv = data;
+	int low, high, intr;
+
+	low = avs_tmon_get_trip_temp(priv, TMON_TRIP_TYPE_LOW);
+	high = avs_tmon_get_trip_temp(priv, TMON_TRIP_TYPE_HIGH);
+	intr = avs_tmon_get_intr_temp(priv);
+
+	dev_dbg(priv->dev, "low/intr/high: %d/%d/%d\n",
+			low, intr, high);
+
+	/* Disable high-temp until next threshold shift */
+	if (intr >= high)
+		avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_HIGH, 0);
+	/* Disable low-temp until next threshold shift */
+	if (intr <= low)
+		avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_LOW, 0);
+
+	/*
+	 * Notify using the interrupt temperature, in case the temperature
+	 * changes before it can next be read out
+	 */
+	thermal_zone_device_update(priv->thermal, intr);
+
+	return IRQ_HANDLED;
+}
+
+static int brcmstb_set_trips(void *data, int low, int high)
+{
+	struct brcmstb_thermal_priv *priv = data;
+
+	dev_dbg(priv->dev, "set trips %d <--> %d\n", low, high);
+
+	/*
+	 * Disable low-temp if "low" is too small. As per thermal framework
+	 * API, we use -INT_MAX rather than INT_MIN.
+	 */
+	if (low <= -INT_MAX) {
+		avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_LOW, 0);
+	} else {
+		avs_tmon_set_trip_temp(priv, TMON_TRIP_TYPE_LOW, low);
+		avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_LOW, 1);
+	}
+
+	/* Disable high-temp if "high" is too big. */
+	if (high == INT_MAX) {
+		avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_HIGH, 0);
+	} else {
+		avs_tmon_set_trip_temp(priv, TMON_TRIP_TYPE_HIGH, high);
+		avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_HIGH, 1);
+	}
+
+	return 0;
+}
+
+static struct thermal_zone_of_device_ops of_ops = {
+	.get_temp	= brcmstb_get_temp,
+	.set_trips	= brcmstb_set_trips,
+};
+
+static const struct of_device_id brcmstb_thermal_id_table[] = {
+	{ .compatible = "brcm,avs-tmon" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, brcmstb_thermal_id_table);
+
+static int brcmstb_thermal_probe(struct platform_device *pdev)
+{
+	struct thermal_zone_device *thermal;
+	struct brcmstb_thermal_priv *priv;
+	struct resource *res;
+	int irq, ret;
+
+	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	priv->tmon_base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(priv->tmon_base))
+		return PTR_ERR(priv->tmon_base);
+
+	priv->dev = &pdev->dev;
+	platform_set_drvdata(pdev, priv);
+
+	thermal = thermal_zone_of_sensor_register(&pdev->dev, 0, priv, &of_ops);
+	if (IS_ERR(thermal)) {
+		ret = PTR_ERR(thermal);
+		dev_err(&pdev->dev, "could not register sensor: %d\n", ret);
+		return ret;
+	}
+
+	priv->thermal = thermal;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(&pdev->dev, "could not get IRQ\n");
+		ret = irq;
+		goto err;
+	}
+	ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
+					brcmstb_tmon_irq_thread, IRQF_ONESHOT,
+					DRV_NAME, priv);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "could not request IRQ: %d\n", ret);
+		goto err;
+	}
+
+	dev_info(&pdev->dev, "registered AVS TMON of-sensor driver\n");
+
+	return 0;
+
+err:
+	thermal_zone_of_sensor_unregister(&pdev->dev, thermal);
+	return ret;
+}
+
+static int brcmstb_thermal_exit(struct platform_device *pdev)
+{
+	struct brcmstb_thermal_priv *priv = platform_get_drvdata(pdev);
+	struct thermal_zone_device *thermal = priv->thermal;
+
+	if (thermal)
+		thermal_zone_of_sensor_unregister(&pdev->dev, priv->thermal);
+
+	return 0;
+}
+
+static struct platform_driver brcmstb_thermal_driver = {
+	.probe = brcmstb_thermal_probe,
+	.remove = brcmstb_thermal_exit,
+	.driver = {
+		.name = DRV_NAME,
+		.of_match_table = brcmstb_thermal_id_table,
+	},
+};
+module_platform_driver(brcmstb_thermal_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Brian Norris");
+MODULE_DESCRIPTION("Broadcom STB AVS TMON thermal driver");