1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Broadcom AVS RO thermal sensor driver 4 * 5 * based on brcmstb_thermal 6 * 7 * Copyright (C) 2020 Stefan Wahren 8 */ 9 10 #include <linux/bitops.h> 11 #include <linux/clk.h> 12 #include <linux/device.h> 13 #include <linux/err.h> 14 #include <linux/io.h> 15 #include <linux/kernel.h> 16 #include <linux/mfd/syscon.h> 17 #include <linux/module.h> 18 #include <linux/platform_device.h> 19 #include <linux/of_device.h> 20 #include <linux/regmap.h> 21 #include <linux/thermal.h> 22 23 #include "../thermal_hwmon.h" 24 25 #define AVS_RO_TEMP_STATUS 0x200 26 #define AVS_RO_TEMP_STATUS_VALID_MSK (BIT(16) | BIT(10)) 27 #define AVS_RO_TEMP_STATUS_DATA_MSK GENMASK(9, 0) 28 29 struct bcm2711_thermal_priv { 30 struct regmap *regmap; 31 struct thermal_zone_device *thermal; 32 }; 33 34 static int bcm2711_get_temp(void *data, int *temp) 35 { 36 struct bcm2711_thermal_priv *priv = data; 37 int slope = thermal_zone_get_slope(priv->thermal); 38 int offset = thermal_zone_get_offset(priv->thermal); 39 u32 val; 40 int ret; 41 long t; 42 43 ret = regmap_read(priv->regmap, AVS_RO_TEMP_STATUS, &val); 44 if (ret) 45 return ret; 46 47 if (!(val & AVS_RO_TEMP_STATUS_VALID_MSK)) 48 return -EIO; 49 50 val &= AVS_RO_TEMP_STATUS_DATA_MSK; 51 52 /* Convert a HW code to a temperature reading (millidegree celsius) */ 53 t = slope * val + offset; 54 55 *temp = t < 0 ? 0 : t; 56 57 return 0; 58 } 59 60 static const struct thermal_zone_of_device_ops bcm2711_thermal_of_ops = { 61 .get_temp = bcm2711_get_temp, 62 }; 63 64 static const struct of_device_id bcm2711_thermal_id_table[] = { 65 { .compatible = "brcm,bcm2711-thermal" }, 66 {}, 67 }; 68 MODULE_DEVICE_TABLE(of, bcm2711_thermal_id_table); 69 70 static int bcm2711_thermal_probe(struct platform_device *pdev) 71 { 72 struct thermal_zone_device *thermal; 73 struct bcm2711_thermal_priv *priv; 74 struct device *dev = &pdev->dev; 75 struct device_node *parent; 76 struct regmap *regmap; 77 int ret; 78 79 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); 80 if (!priv) 81 return -ENOMEM; 82 83 /* get regmap from syscon node */ 84 parent = of_get_parent(dev->of_node); /* parent should be syscon node */ 85 regmap = syscon_node_to_regmap(parent); 86 of_node_put(parent); 87 if (IS_ERR(regmap)) { 88 ret = PTR_ERR(regmap); 89 dev_err(dev, "failed to get regmap: %d\n", ret); 90 return ret; 91 } 92 priv->regmap = regmap; 93 94 thermal = devm_thermal_zone_of_sensor_register(dev, 0, priv, 95 &bcm2711_thermal_of_ops); 96 if (IS_ERR(thermal)) { 97 ret = PTR_ERR(thermal); 98 dev_err(dev, "could not register sensor: %d\n", ret); 99 return ret; 100 } 101 102 priv->thermal = thermal; 103 104 thermal->tzp->no_hwmon = false; 105 return thermal_add_hwmon_sysfs(thermal); 106 } 107 108 static struct platform_driver bcm2711_thermal_driver = { 109 .probe = bcm2711_thermal_probe, 110 .driver = { 111 .name = "bcm2711_thermal", 112 .of_match_table = bcm2711_thermal_id_table, 113 }, 114 }; 115 module_platform_driver(bcm2711_thermal_driver); 116 117 MODULE_LICENSE("GPL"); 118 MODULE_AUTHOR("Stefan Wahren"); 119 MODULE_DESCRIPTION("Broadcom AVS RO thermal sensor driver"); 120