1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Dove thermal sensor driver 4 * 5 * Copyright (C) 2013 Andrew Lunn <andrew@lunn.ch> 6 */ 7 #include <linux/device.h> 8 #include <linux/err.h> 9 #include <linux/io.h> 10 #include <linux/kernel.h> 11 #include <linux/of.h> 12 #include <linux/module.h> 13 #include <linux/platform_device.h> 14 #include <linux/thermal.h> 15 16 #define DOVE_THERMAL_TEMP_OFFSET 1 17 #define DOVE_THERMAL_TEMP_MASK 0x1FF 18 19 /* Dove Thermal Manager Control and Status Register */ 20 #define PMU_TM_DISABLE_OFFS 0 21 #define PMU_TM_DISABLE_MASK (0x1 << PMU_TM_DISABLE_OFFS) 22 23 /* Dove Theraml Diode Control 0 Register */ 24 #define PMU_TDC0_SW_RST_MASK (0x1 << 1) 25 #define PMU_TDC0_SEL_VCAL_OFFS 5 26 #define PMU_TDC0_SEL_VCAL_MASK (0x3 << PMU_TDC0_SEL_VCAL_OFFS) 27 #define PMU_TDC0_REF_CAL_CNT_OFFS 11 28 #define PMU_TDC0_REF_CAL_CNT_MASK (0x1FF << PMU_TDC0_REF_CAL_CNT_OFFS) 29 #define PMU_TDC0_AVG_NUM_OFFS 25 30 #define PMU_TDC0_AVG_NUM_MASK (0x7 << PMU_TDC0_AVG_NUM_OFFS) 31 32 /* Dove Thermal Diode Control 1 Register */ 33 #define PMU_TEMP_DIOD_CTRL1_REG 0x04 34 #define PMU_TDC1_TEMP_VALID_MASK (0x1 << 10) 35 36 /* Dove Thermal Sensor Dev Structure */ 37 struct dove_thermal_priv { 38 void __iomem *sensor; 39 void __iomem *control; 40 }; 41 42 static int dove_init_sensor(const struct dove_thermal_priv *priv) 43 { 44 u32 reg; 45 u32 i; 46 47 /* Configure the Diode Control Register #0 */ 48 reg = readl_relaxed(priv->control); 49 50 /* Use average of 2 */ 51 reg &= ~PMU_TDC0_AVG_NUM_MASK; 52 reg |= (0x1 << PMU_TDC0_AVG_NUM_OFFS); 53 54 /* Reference calibration value */ 55 reg &= ~PMU_TDC0_REF_CAL_CNT_MASK; 56 reg |= (0x0F1 << PMU_TDC0_REF_CAL_CNT_OFFS); 57 58 /* Set the high level reference for calibration */ 59 reg &= ~PMU_TDC0_SEL_VCAL_MASK; 60 reg |= (0x2 << PMU_TDC0_SEL_VCAL_OFFS); 61 writel(reg, priv->control); 62 63 /* Reset the sensor */ 64 reg = readl_relaxed(priv->control); 65 writel((reg | PMU_TDC0_SW_RST_MASK), priv->control); 66 writel(reg, priv->control); 67 68 /* Enable the sensor */ 69 reg = readl_relaxed(priv->sensor); 70 reg &= ~PMU_TM_DISABLE_MASK; 71 writel(reg, priv->sensor); 72 73 /* Poll the sensor for the first reading */ 74 for (i = 0; i < 1000000; i++) { 75 reg = readl_relaxed(priv->sensor); 76 if (reg & DOVE_THERMAL_TEMP_MASK) 77 break; 78 } 79 80 if (i == 1000000) 81 return -EIO; 82 83 return 0; 84 } 85 86 static int dove_get_temp(struct thermal_zone_device *thermal, 87 int *temp) 88 { 89 unsigned long reg; 90 struct dove_thermal_priv *priv = thermal->devdata; 91 92 /* Valid check */ 93 reg = readl_relaxed(priv->control + PMU_TEMP_DIOD_CTRL1_REG); 94 if ((reg & PMU_TDC1_TEMP_VALID_MASK) == 0x0) { 95 dev_err(&thermal->device, 96 "Temperature sensor reading not valid\n"); 97 return -EIO; 98 } 99 100 /* 101 * Calculate temperature. According to Marvell internal 102 * documentation the formula for this is: 103 * Celsius = (322-reg)/1.3625 104 */ 105 reg = readl_relaxed(priv->sensor); 106 reg = (reg >> DOVE_THERMAL_TEMP_OFFSET) & DOVE_THERMAL_TEMP_MASK; 107 *temp = ((3220000000UL - (10000000UL * reg)) / 13625); 108 109 return 0; 110 } 111 112 static struct thermal_zone_device_ops ops = { 113 .get_temp = dove_get_temp, 114 }; 115 116 static const struct of_device_id dove_thermal_id_table[] = { 117 { .compatible = "marvell,dove-thermal" }, 118 {} 119 }; 120 121 static int dove_thermal_probe(struct platform_device *pdev) 122 { 123 struct thermal_zone_device *thermal = NULL; 124 struct dove_thermal_priv *priv; 125 int ret; 126 127 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); 128 if (!priv) 129 return -ENOMEM; 130 131 priv->sensor = devm_platform_get_and_ioremap_resource(pdev, 0, NULL); 132 if (IS_ERR(priv->sensor)) 133 return PTR_ERR(priv->sensor); 134 135 priv->control = devm_platform_get_and_ioremap_resource(pdev, 1, NULL); 136 if (IS_ERR(priv->control)) 137 return PTR_ERR(priv->control); 138 139 ret = dove_init_sensor(priv); 140 if (ret) { 141 dev_err(&pdev->dev, "Failed to initialize sensor\n"); 142 return ret; 143 } 144 145 thermal = thermal_zone_device_register("dove_thermal", 0, 0, 146 priv, &ops, NULL, 0, 0); 147 if (IS_ERR(thermal)) { 148 dev_err(&pdev->dev, 149 "Failed to register thermal zone device\n"); 150 return PTR_ERR(thermal); 151 } 152 153 ret = thermal_zone_device_enable(thermal); 154 if (ret) { 155 thermal_zone_device_unregister(thermal); 156 return ret; 157 } 158 159 platform_set_drvdata(pdev, thermal); 160 161 return 0; 162 } 163 164 static int dove_thermal_exit(struct platform_device *pdev) 165 { 166 struct thermal_zone_device *dove_thermal = 167 platform_get_drvdata(pdev); 168 169 thermal_zone_device_unregister(dove_thermal); 170 171 return 0; 172 } 173 174 MODULE_DEVICE_TABLE(of, dove_thermal_id_table); 175 176 static struct platform_driver dove_thermal_driver = { 177 .probe = dove_thermal_probe, 178 .remove = dove_thermal_exit, 179 .driver = { 180 .name = "dove_thermal", 181 .of_match_table = dove_thermal_id_table, 182 }, 183 }; 184 185 module_platform_driver(dove_thermal_driver); 186 187 MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>"); 188 MODULE_DESCRIPTION("Dove thermal driver"); 189 MODULE_LICENSE("GPL"); 190