thermal/broadcom/bcm2711_thermal.c

0001 // SPDX-License-Identifier: GPL-2.0+
0002 /*
0003  * Broadcom AVS RO thermal sensor driver
0004  *
0005  * based on brcmstb_thermal
0006  *
0007  * Copyright (C) 2020 Stefan Wahren
0008  */
0009
0010 #include <linux/bitops.h>
0011 #include <linux/clk.h>
0012 #include <linux/device.h>
0013 #include <linux/err.h>
0014 #include <linux/io.h>
0015 #include <linux/kernel.h>
0016 #include <linux/mfd/syscon.h>
0017 #include <linux/module.h>
0018 #include <linux/platform_device.h>
0019 #include <linux/of_device.h>
0020 #include <linux/regmap.h>
0021 #include <linux/thermal.h>
0022
0023 #include "../thermal_hwmon.h"
0024
0025 #define AVS_RO_TEMP_STATUS      0x200
0026 #define AVS_RO_TEMP_STATUS_VALID_MSK    (BIT(16) | BIT(10))
0027 #define AVS_RO_TEMP_STATUS_DATA_MSK GENMASK(9, 0)
0028
0029 struct bcm2711_thermal_priv {
0030     struct regmap *regmap;
0031     struct thermal_zone_device *thermal;
0032 };
0033
0034 static int bcm2711_get_temp(void *data, int *temp)
0035 {
0036     struct bcm2711_thermal_priv *priv = data;
0037     int slope = thermal_zone_get_slope(priv->thermal);
0038     int offset = thermal_zone_get_offset(priv->thermal);
0039     u32 val;
0040     int ret;
0041
0042     ret = regmap_read(priv->regmap, AVS_RO_TEMP_STATUS, &val);
0043     if (ret)
0044         return ret;
0045
0046     if (!(val & AVS_RO_TEMP_STATUS_VALID_MSK))
0047         return -EIO;
0048
0049     val &= AVS_RO_TEMP_STATUS_DATA_MSK;
0050
0051     /* Convert a HW code to a temperature reading (millidegree celsius) */
0052     *temp = slope * val + offset;
0053
0054     return 0;
0055 }
0056
0057 static const struct thermal_zone_of_device_ops bcm2711_thermal_of_ops = {
0058     .get_temp   = bcm2711_get_temp,
0059 };
0060
0061 static const struct of_device_id bcm2711_thermal_id_table[] = {
0062     { .compatible = "brcm,bcm2711-thermal" },
0063     {},
0064 };
0065 MODULE_DEVICE_TABLE(of, bcm2711_thermal_id_table);
0066
0067 static int bcm2711_thermal_probe(struct platform_device *pdev)
0068 {
0069     struct thermal_zone_device *thermal;
0070     struct bcm2711_thermal_priv *priv;
0071     struct device *dev = &pdev->dev;
0072     struct device_node *parent;
0073     struct regmap *regmap;
0074     int ret;
0075
0076     priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
0077     if (!priv)
0078         return -ENOMEM;
0079
0080     /* get regmap from syscon node */
0081     parent = of_get_parent(dev->of_node); /* parent should be syscon node */
0082     regmap = syscon_node_to_regmap(parent);
0083     of_node_put(parent);
0084     if (IS_ERR(regmap)) {
0085         ret = PTR_ERR(regmap);
0086         dev_err(dev, "failed to get regmap: %d\n", ret);
0087         return ret;
0088     }
0089     priv->regmap = regmap;
0090
0091     thermal = devm_thermal_zone_of_sensor_register(dev, 0, priv,
0092                                &bcm2711_thermal_of_ops);
0093     if (IS_ERR(thermal)) {
0094         ret = PTR_ERR(thermal);
0095         dev_err(dev, "could not register sensor: %d\n", ret);
0096         return ret;
0097     }
0098
0099     priv->thermal = thermal;
0100
0101     thermal->tzp->no_hwmon = false;
0102     return thermal_add_hwmon_sysfs(thermal);
0103 }
0104
0105 static struct platform_driver bcm2711_thermal_driver = {
0106     .probe = bcm2711_thermal_probe,
0107     .driver = {
0108         .name = "bcm2711_thermal",
0109         .of_match_table = bcm2711_thermal_id_table,
0110     },
0111 };
0112 module_platform_driver(bcm2711_thermal_driver);
0113
0114 MODULE_LICENSE("GPL");
0115 MODULE_AUTHOR("Stefan Wahren");
0116 MODULE_DESCRIPTION("Broadcom AVS RO thermal sensor driver");