1 /* 2 * OMAP thermal driver interface 3 * 4 * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/ 5 * Contact: 6 * Eduardo Valentin <eduardo.valentin@ti.com> 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License 10 * version 2 as published by the Free Software Foundation. 11 * 12 * This program is distributed in the hope that it will be useful, but 13 * WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 20 * 02110-1301 USA 21 * 22 */ 23 24 #include <linux/device.h> 25 #include <linux/err.h> 26 #include <linux/mutex.h> 27 #include <linux/gfp.h> 28 #include <linux/kernel.h> 29 #include <linux/workqueue.h> 30 #include <linux/thermal.h> 31 #include <linux/cpumask.h> 32 #include <linux/cpu_cooling.h> 33 #include <linux/of.h> 34 35 #include "ti-thermal.h" 36 #include "ti-bandgap.h" 37 38 /* common data structures */ 39 struct ti_thermal_data { 40 struct thermal_zone_device *ti_thermal; 41 struct thermal_zone_device *pcb_tz; 42 struct thermal_cooling_device *cool_dev; 43 struct ti_bandgap *bgp; 44 enum thermal_device_mode mode; 45 struct work_struct thermal_wq; 46 int sensor_id; 47 bool our_zone; 48 }; 49 50 static void ti_thermal_work(struct work_struct *work) 51 { 52 struct ti_thermal_data *data = container_of(work, 53 struct ti_thermal_data, thermal_wq); 54 55 thermal_zone_device_update(data->ti_thermal, THERMAL_EVENT_UNSPECIFIED); 56 57 dev_dbg(&data->ti_thermal->device, "updated thermal zone %s\n", 58 data->ti_thermal->type); 59 } 60 61 /** 62 * ti_thermal_hotspot_temperature - returns sensor extrapolated temperature 63 * @t: omap sensor temperature 64 * @s: omap sensor slope value 65 * @c: omap sensor const value 66 */ 67 static inline int ti_thermal_hotspot_temperature(int t, int s, int c) 68 { 69 int delta = t * s / 1000 + c; 70 71 if (delta < 0) 72 delta = 0; 73 74 return t + delta; 75 } 76 77 /* thermal zone ops */ 78 /* Get temperature callback function for thermal zone */ 79 static inline int __ti_thermal_get_temp(void *devdata, int *temp) 80 { 81 struct thermal_zone_device *pcb_tz = NULL; 82 struct ti_thermal_data *data = devdata; 83 struct ti_bandgap *bgp; 84 const struct ti_temp_sensor *s; 85 int ret, tmp, slope, constant; 86 int pcb_temp; 87 88 if (!data) 89 return 0; 90 91 bgp = data->bgp; 92 s = &bgp->conf->sensors[data->sensor_id]; 93 94 ret = ti_bandgap_read_temperature(bgp, data->sensor_id, &tmp); 95 if (ret) 96 return ret; 97 98 /* Default constants */ 99 slope = thermal_zone_get_slope(data->ti_thermal); 100 constant = thermal_zone_get_offset(data->ti_thermal); 101 102 pcb_tz = data->pcb_tz; 103 /* In case pcb zone is available, use the extrapolation rule with it */ 104 if (!IS_ERR(pcb_tz)) { 105 ret = thermal_zone_get_temp(pcb_tz, &pcb_temp); 106 if (!ret) { 107 tmp -= pcb_temp; /* got a valid PCB temp */ 108 slope = s->slope_pcb; 109 constant = s->constant_pcb; 110 } else { 111 dev_err(bgp->dev, 112 "Failed to read PCB state. Using defaults\n"); 113 ret = 0; 114 } 115 } 116 *temp = ti_thermal_hotspot_temperature(tmp, slope, constant); 117 118 return ret; 119 } 120 121 static inline int ti_thermal_get_temp(struct thermal_zone_device *thermal, 122 int *temp) 123 { 124 struct ti_thermal_data *data = thermal->devdata; 125 126 return __ti_thermal_get_temp(data, temp); 127 } 128 129 static int __ti_thermal_get_trend(void *p, int trip, enum thermal_trend *trend) 130 { 131 struct ti_thermal_data *data = p; 132 struct ti_bandgap *bgp; 133 int id, tr, ret = 0; 134 135 bgp = data->bgp; 136 id = data->sensor_id; 137 138 ret = ti_bandgap_get_trend(bgp, id, &tr); 139 if (ret) 140 return ret; 141 142 if (tr > 0) 143 *trend = THERMAL_TREND_RAISING; 144 else if (tr < 0) 145 *trend = THERMAL_TREND_DROPPING; 146 else 147 *trend = THERMAL_TREND_STABLE; 148 149 return 0; 150 } 151 152 static const struct thermal_zone_of_device_ops ti_of_thermal_ops = { 153 .get_temp = __ti_thermal_get_temp, 154 .get_trend = __ti_thermal_get_trend, 155 }; 156 157 static struct ti_thermal_data 158 *ti_thermal_build_data(struct ti_bandgap *bgp, int id) 159 { 160 struct ti_thermal_data *data; 161 162 data = devm_kzalloc(bgp->dev, sizeof(*data), GFP_KERNEL); 163 if (!data) { 164 dev_err(bgp->dev, "kzalloc fail\n"); 165 return NULL; 166 } 167 data->sensor_id = id; 168 data->bgp = bgp; 169 data->mode = THERMAL_DEVICE_ENABLED; 170 /* pcb_tz will be either valid or PTR_ERR() */ 171 data->pcb_tz = thermal_zone_get_zone_by_name("pcb"); 172 INIT_WORK(&data->thermal_wq, ti_thermal_work); 173 174 return data; 175 } 176 177 int ti_thermal_expose_sensor(struct ti_bandgap *bgp, int id, 178 char *domain) 179 { 180 struct ti_thermal_data *data; 181 182 data = ti_bandgap_get_sensor_data(bgp, id); 183 184 if (!data || IS_ERR(data)) 185 data = ti_thermal_build_data(bgp, id); 186 187 if (!data) 188 return -EINVAL; 189 190 /* in case this is specified by DT */ 191 data->ti_thermal = devm_thermal_zone_of_sensor_register(bgp->dev, id, 192 data, &ti_of_thermal_ops); 193 if (IS_ERR(data->ti_thermal)) { 194 dev_err(bgp->dev, "thermal zone device is NULL\n"); 195 return PTR_ERR(data->ti_thermal); 196 } 197 198 ti_bandgap_set_sensor_data(bgp, id, data); 199 ti_bandgap_write_update_interval(bgp, data->sensor_id, 200 data->ti_thermal->polling_delay); 201 202 return 0; 203 } 204 205 int ti_thermal_remove_sensor(struct ti_bandgap *bgp, int id) 206 { 207 struct ti_thermal_data *data; 208 209 data = ti_bandgap_get_sensor_data(bgp, id); 210 211 if (data && data->ti_thermal) { 212 if (data->our_zone) 213 thermal_zone_device_unregister(data->ti_thermal); 214 } 215 216 return 0; 217 } 218 219 int ti_thermal_report_sensor_temperature(struct ti_bandgap *bgp, int id) 220 { 221 struct ti_thermal_data *data; 222 223 data = ti_bandgap_get_sensor_data(bgp, id); 224 225 schedule_work(&data->thermal_wq); 226 227 return 0; 228 } 229 230 int ti_thermal_register_cpu_cooling(struct ti_bandgap *bgp, int id) 231 { 232 struct ti_thermal_data *data; 233 struct device_node *np = bgp->dev->of_node; 234 235 /* 236 * We are assuming here that if one deploys the zone 237 * using DT, then it must be aware that the cooling device 238 * loading has to happen via cpufreq driver. 239 */ 240 if (of_find_property(np, "#thermal-sensor-cells", NULL)) 241 return 0; 242 243 data = ti_bandgap_get_sensor_data(bgp, id); 244 if (!data || IS_ERR(data)) 245 data = ti_thermal_build_data(bgp, id); 246 247 if (!data) 248 return -EINVAL; 249 250 /* Register cooling device */ 251 data->cool_dev = cpufreq_cooling_register(cpu_present_mask); 252 if (IS_ERR(data->cool_dev)) { 253 int ret = PTR_ERR(data->cool_dev); 254 255 if (ret != -EPROBE_DEFER) 256 dev_err(bgp->dev, 257 "Failed to register cpu cooling device %d\n", 258 ret); 259 260 return ret; 261 } 262 ti_bandgap_set_sensor_data(bgp, id, data); 263 264 return 0; 265 } 266 267 int ti_thermal_unregister_cpu_cooling(struct ti_bandgap *bgp, int id) 268 { 269 struct ti_thermal_data *data; 270 271 data = ti_bandgap_get_sensor_data(bgp, id); 272 273 if (data) 274 cpufreq_cooling_unregister(data->cool_dev); 275 276 return 0; 277 } 278