1 /* 2 * Dove thermal sensor driver 3 * 4 * Copyright (C) 2013 Andrew Lunn <andrew@lunn.ch> 5 * 6 * This software is licensed under the terms of the GNU General Public 7 * License version 2, as published by the Free Software Foundation, and 8 * may be copied, distributed, and modified under those terms. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 */ 16 #include <linux/device.h> 17 #include <linux/err.h> 18 #include <linux/io.h> 19 #include <linux/kernel.h> 20 #include <linux/of.h> 21 #include <linux/module.h> 22 #include <linux/platform_device.h> 23 #include <linux/thermal.h> 24 25 #define DOVE_THERMAL_TEMP_OFFSET 1 26 #define DOVE_THERMAL_TEMP_MASK 0x1FF 27 28 /* Dove Thermal Manager Control and Status Register */ 29 #define PMU_TM_DISABLE_OFFS 0 30 #define PMU_TM_DISABLE_MASK (0x1 << PMU_TM_DISABLE_OFFS) 31 32 /* Dove Theraml Diode Control 0 Register */ 33 #define PMU_TDC0_SW_RST_MASK (0x1 << 1) 34 #define PMU_TDC0_SEL_VCAL_OFFS 5 35 #define PMU_TDC0_SEL_VCAL_MASK (0x3 << PMU_TDC0_SEL_VCAL_OFFS) 36 #define PMU_TDC0_REF_CAL_CNT_OFFS 11 37 #define PMU_TDC0_REF_CAL_CNT_MASK (0x1FF << PMU_TDC0_REF_CAL_CNT_OFFS) 38 #define PMU_TDC0_AVG_NUM_OFFS 25 39 #define PMU_TDC0_AVG_NUM_MASK (0x7 << PMU_TDC0_AVG_NUM_OFFS) 40 41 /* Dove Thermal Diode Control 1 Register */ 42 #define PMU_TEMP_DIOD_CTRL1_REG 0x04 43 #define PMU_TDC1_TEMP_VALID_MASK (0x1 << 10) 44 45 /* Dove Thermal Sensor Dev Structure */ 46 struct dove_thermal_priv { 47 void __iomem *sensor; 48 void __iomem *control; 49 }; 50 51 static int dove_init_sensor(const struct dove_thermal_priv *priv) 52 { 53 u32 reg; 54 u32 i; 55 56 /* Configure the Diode Control Register #0 */ 57 reg = readl_relaxed(priv->control); 58 59 /* Use average of 2 */ 60 reg &= ~PMU_TDC0_AVG_NUM_MASK; 61 reg |= (0x1 << PMU_TDC0_AVG_NUM_OFFS); 62 63 /* Reference calibration value */ 64 reg &= ~PMU_TDC0_REF_CAL_CNT_MASK; 65 reg |= (0x0F1 << PMU_TDC0_REF_CAL_CNT_OFFS); 66 67 /* Set the high level reference for calibration */ 68 reg &= ~PMU_TDC0_SEL_VCAL_MASK; 69 reg |= (0x2 << PMU_TDC0_SEL_VCAL_OFFS); 70 writel(reg, priv->control); 71 72 /* Reset the sensor */ 73 reg = readl_relaxed(priv->control); 74 writel((reg | PMU_TDC0_SW_RST_MASK), priv->control); 75 writel(reg, priv->control); 76 77 /* Enable the sensor */ 78 reg = readl_relaxed(priv->sensor); 79 reg &= ~PMU_TM_DISABLE_MASK; 80 writel(reg, priv->sensor); 81 82 /* Poll the sensor for the first reading */ 83 for (i = 0; i < 1000000; i++) { 84 reg = readl_relaxed(priv->sensor); 85 if (reg & DOVE_THERMAL_TEMP_MASK) 86 break; 87 } 88 89 if (i == 1000000) 90 return -EIO; 91 92 return 0; 93 } 94 95 static int dove_get_temp(struct thermal_zone_device *thermal, 96 unsigned long *temp) 97 { 98 unsigned long reg; 99 struct dove_thermal_priv *priv = thermal->devdata; 100 101 /* Valid check */ 102 reg = readl_relaxed(priv->control + PMU_TEMP_DIOD_CTRL1_REG); 103 if ((reg & PMU_TDC1_TEMP_VALID_MASK) == 0x0) { 104 dev_err(&thermal->device, 105 "Temperature sensor reading not valid\n"); 106 return -EIO; 107 } 108 109 /* 110 * Calculate temperature. According to Marvell internal 111 * documentation the formula for this is: 112 * Celsius = (322-reg)/1.3625 113 */ 114 reg = readl_relaxed(priv->sensor); 115 reg = (reg >> DOVE_THERMAL_TEMP_OFFSET) & DOVE_THERMAL_TEMP_MASK; 116 *temp = ((3220000000UL - (10000000UL * reg)) / 13625); 117 118 return 0; 119 } 120 121 static struct thermal_zone_device_ops ops = { 122 .get_temp = dove_get_temp, 123 }; 124 125 static const struct of_device_id dove_thermal_id_table[] = { 126 { .compatible = "marvell,dove-thermal" }, 127 {} 128 }; 129 130 static int dove_thermal_probe(struct platform_device *pdev) 131 { 132 struct thermal_zone_device *thermal = NULL; 133 struct dove_thermal_priv *priv; 134 struct resource *res; 135 int ret; 136 137 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); 138 if (!priv) 139 return -ENOMEM; 140 141 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 142 priv->sensor = devm_ioremap_resource(&pdev->dev, res); 143 if (IS_ERR(priv->sensor)) 144 return PTR_ERR(priv->sensor); 145 146 res = platform_get_resource(pdev, IORESOURCE_MEM, 1); 147 priv->control = devm_ioremap_resource(&pdev->dev, res); 148 if (IS_ERR(priv->control)) 149 return PTR_ERR(priv->control); 150 151 ret = dove_init_sensor(priv); 152 if (ret) { 153 dev_err(&pdev->dev, "Failed to initialize sensor\n"); 154 return ret; 155 } 156 157 thermal = thermal_zone_device_register("dove_thermal", 0, 0, 158 priv, &ops, NULL, 0, 0); 159 if (IS_ERR(thermal)) { 160 dev_err(&pdev->dev, 161 "Failed to register thermal zone device\n"); 162 return PTR_ERR(thermal); 163 } 164 165 platform_set_drvdata(pdev, thermal); 166 167 return 0; 168 } 169 170 static int dove_thermal_exit(struct platform_device *pdev) 171 { 172 struct thermal_zone_device *dove_thermal = 173 platform_get_drvdata(pdev); 174 175 thermal_zone_device_unregister(dove_thermal); 176 177 return 0; 178 } 179 180 MODULE_DEVICE_TABLE(of, dove_thermal_id_table); 181 182 static struct platform_driver dove_thermal_driver = { 183 .probe = dove_thermal_probe, 184 .remove = dove_thermal_exit, 185 .driver = { 186 .name = "dove_thermal", 187 .of_match_table = dove_thermal_id_table, 188 }, 189 }; 190 191 module_platform_driver(dove_thermal_driver); 192 193 MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>"); 194 MODULE_DESCRIPTION("Dove thermal driver"); 195 MODULE_LICENSE("GPL"); 196