--- /dev/null
+/*
+ * 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");
projects / platform / kernel / linux-rpi.git / commitdiff