| 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
| 2 | /* |
| 3 | * db8500_thermal.c - DB8500 Thermal Management Implementation |
| 4 | * |
| 5 | * Copyright (C) 2012 ST-Ericsson |
| 6 | * Copyright (C) 2012-2019 Linaro Ltd. |
| 7 | * |
| 8 | * Authors: Hongbo Zhang, Linus Walleij |
| 9 | */ |
| 10 | |
| 11 | #include <linux/cpu_cooling.h> |
| 12 | #include <linux/interrupt.h> |
| 13 | #include <linux/mfd/dbx500-prcmu.h> |
| 14 | #include <linux/module.h> |
| 15 | #include <linux/of.h> |
| 16 | #include <linux/platform_device.h> |
| 17 | #include <linux/slab.h> |
| 18 | #include <linux/thermal.h> |
| 19 | |
| 20 | #define PRCMU_DEFAULT_MEASURE_TIME 0xFFF |
| 21 | #define PRCMU_DEFAULT_LOW_TEMP 0 |
| 22 | |
| 23 | /** |
| 24 | * db8500_thermal_points - the interpolation points that trigger |
| 25 | * interrupts |
| 26 | */ |
| 27 | static const unsigned long db8500_thermal_points[] = { |
| 28 | 15000, |
| 29 | 20000, |
| 30 | 25000, |
| 31 | 30000, |
| 32 | 35000, |
| 33 | 40000, |
| 34 | 45000, |
| 35 | 50000, |
| 36 | 55000, |
| 37 | 60000, |
| 38 | 65000, |
| 39 | 70000, |
| 40 | 75000, |
| 41 | 80000, |
| 42 | /* |
| 43 | * This is where things start to get really bad for the |
| 44 | * SoC and the thermal zones should be set up to trigger |
| 45 | * critical temperature at 85000 mC so we don't get above |
| 46 | * this point. |
| 47 | */ |
| 48 | 85000, |
| 49 | 90000, |
| 50 | 95000, |
| 51 | 100000, |
| 52 | }; |
| 53 | |
| 54 | struct db8500_thermal_zone { |
| 55 | struct thermal_zone_device *tz; |
| 56 | struct device *dev; |
| 57 | unsigned long interpolated_temp; |
| 58 | unsigned int cur_index; |
| 59 | }; |
| 60 | |
| 61 | /* Callback to get current temperature */ |
| 62 | static int db8500_thermal_get_temp(struct thermal_zone_device *tz, int *temp) |
| 63 | { |
| 64 | struct db8500_thermal_zone *th = thermal_zone_device_priv(tz); |
| 65 | |
| 66 | /* |
| 67 | * TODO: There is no PRCMU interface to get temperature data currently, |
| 68 | * so a pseudo temperature is returned , it works for thermal framework |
| 69 | * and this will be fixed when the PRCMU interface is available. |
| 70 | */ |
| 71 | *temp = th->interpolated_temp; |
| 72 | |
| 73 | return 0; |
| 74 | } |
| 75 | |
| 76 | static const struct thermal_zone_device_ops thdev_ops = { |
| 77 | .get_temp = db8500_thermal_get_temp, |
| 78 | }; |
| 79 | |
| 80 | static void db8500_thermal_update_config(struct db8500_thermal_zone *th, |
| 81 | unsigned int idx, |
| 82 | unsigned long next_low, |
| 83 | unsigned long next_high) |
| 84 | { |
| 85 | prcmu_stop_temp_sense(); |
| 86 | |
| 87 | th->cur_index = idx; |
| 88 | th->interpolated_temp = (next_low + next_high)/2; |
| 89 | |
| 90 | /* |
| 91 | * The PRCMU accept absolute temperatures in celsius so divide |
| 92 | * down the millicelsius with 1000 |
| 93 | */ |
| 94 | prcmu_config_hotmon((u8)(next_low/1000), (u8)(next_high/1000)); |
| 95 | prcmu_start_temp_sense(PRCMU_DEFAULT_MEASURE_TIME); |
| 96 | } |
| 97 | |
| 98 | static irqreturn_t prcmu_low_irq_handler(int irq, void *irq_data) |
| 99 | { |
| 100 | struct db8500_thermal_zone *th = irq_data; |
| 101 | unsigned int idx = th->cur_index; |
| 102 | unsigned long next_low, next_high; |
| 103 | |
| 104 | if (idx == 0) |
| 105 | /* Meaningless for thermal management, ignoring it */ |
| 106 | return IRQ_HANDLED; |
| 107 | |
| 108 | if (idx == 1) { |
| 109 | next_high = db8500_thermal_points[0]; |
| 110 | next_low = PRCMU_DEFAULT_LOW_TEMP; |
| 111 | } else { |
| 112 | next_high = db8500_thermal_points[idx - 1]; |
| 113 | next_low = db8500_thermal_points[idx - 2]; |
| 114 | } |
| 115 | idx -= 1; |
| 116 | |
| 117 | db8500_thermal_update_config(th, idx, next_low, next_high); |
| 118 | dev_dbg(th->dev, |
| 119 | "PRCMU set max %ld, min %ld\n", next_high, next_low); |
| 120 | |
| 121 | thermal_zone_device_update(th->tz, THERMAL_EVENT_UNSPECIFIED); |
| 122 | |
| 123 | return IRQ_HANDLED; |
| 124 | } |
| 125 | |
| 126 | static irqreturn_t prcmu_high_irq_handler(int irq, void *irq_data) |
| 127 | { |
| 128 | struct db8500_thermal_zone *th = irq_data; |
| 129 | unsigned int idx = th->cur_index; |
| 130 | unsigned long next_low, next_high; |
| 131 | int num_points = ARRAY_SIZE(db8500_thermal_points); |
| 132 | |
| 133 | if (idx < num_points - 1) { |
| 134 | next_high = db8500_thermal_points[idx+1]; |
| 135 | next_low = db8500_thermal_points[idx]; |
| 136 | idx += 1; |
| 137 | |
| 138 | db8500_thermal_update_config(th, idx, next_low, next_high); |
| 139 | |
| 140 | dev_dbg(th->dev, |
| 141 | "PRCMU set max %ld, min %ld\n", next_high, next_low); |
| 142 | } else if (idx == num_points - 1) |
| 143 | /* So we roof out 1 degree over the max point */ |
| 144 | th->interpolated_temp = db8500_thermal_points[idx] + 1; |
| 145 | |
| 146 | thermal_zone_device_update(th->tz, THERMAL_EVENT_UNSPECIFIED); |
| 147 | |
| 148 | return IRQ_HANDLED; |
| 149 | } |
| 150 | |
| 151 | static int db8500_thermal_probe(struct platform_device *pdev) |
| 152 | { |
| 153 | struct db8500_thermal_zone *th = NULL; |
| 154 | struct device *dev = &pdev->dev; |
| 155 | int low_irq, high_irq, ret = 0; |
| 156 | |
| 157 | th = devm_kzalloc(dev, sizeof(*th), GFP_KERNEL); |
| 158 | if (!th) |
| 159 | return -ENOMEM; |
| 160 | |
| 161 | th->dev = dev; |
| 162 | |
| 163 | low_irq = platform_get_irq_byname(pdev, "IRQ_HOTMON_LOW"); |
| 164 | if (low_irq < 0) |
| 165 | return low_irq; |
| 166 | |
| 167 | ret = devm_request_threaded_irq(dev, low_irq, NULL, |
| 168 | prcmu_low_irq_handler, IRQF_NO_SUSPEND | IRQF_ONESHOT, |
| 169 | "dbx500_temp_low", th); |
| 170 | if (ret < 0) { |
| 171 | dev_err(dev, "failed to allocate temp low irq\n"); |
| 172 | return ret; |
| 173 | } |
| 174 | |
| 175 | high_irq = platform_get_irq_byname(pdev, "IRQ_HOTMON_HIGH"); |
| 176 | if (high_irq < 0) |
| 177 | return high_irq; |
| 178 | |
| 179 | ret = devm_request_threaded_irq(dev, high_irq, NULL, |
| 180 | prcmu_high_irq_handler, IRQF_NO_SUSPEND | IRQF_ONESHOT, |
| 181 | "dbx500_temp_high", th); |
| 182 | if (ret < 0) { |
| 183 | dev_err(dev, "failed to allocate temp high irq\n"); |
| 184 | return ret; |
| 185 | } |
| 186 | |
| 187 | /* register of thermal sensor and get info from DT */ |
| 188 | th->tz = devm_thermal_of_zone_register(dev, 0, th, &thdev_ops); |
| 189 | if (IS_ERR(th->tz)) { |
| 190 | dev_err(dev, "register thermal zone sensor failed\n"); |
| 191 | return PTR_ERR(th->tz); |
| 192 | } |
| 193 | dev_info(dev, "thermal zone sensor registered\n"); |
| 194 | |
| 195 | /* Start measuring at the lowest point */ |
| 196 | db8500_thermal_update_config(th, 0, PRCMU_DEFAULT_LOW_TEMP, |
| 197 | db8500_thermal_points[0]); |
| 198 | |
| 199 | platform_set_drvdata(pdev, th); |
| 200 | |
| 201 | return 0; |
| 202 | } |
| 203 | |
| 204 | static int db8500_thermal_suspend(struct platform_device *pdev, |
| 205 | pm_message_t state) |
| 206 | { |
| 207 | prcmu_stop_temp_sense(); |
| 208 | |
| 209 | return 0; |
| 210 | } |
| 211 | |
| 212 | static int db8500_thermal_resume(struct platform_device *pdev) |
| 213 | { |
| 214 | struct db8500_thermal_zone *th = platform_get_drvdata(pdev); |
| 215 | |
| 216 | /* Resume and start measuring at the lowest point */ |
| 217 | db8500_thermal_update_config(th, 0, PRCMU_DEFAULT_LOW_TEMP, |
| 218 | db8500_thermal_points[0]); |
| 219 | |
| 220 | return 0; |
| 221 | } |
| 222 | |
| 223 | static const struct of_device_id db8500_thermal_match[] = { |
| 224 | { .compatible = "stericsson,db8500-thermal" }, |
| 225 | {}, |
| 226 | }; |
| 227 | MODULE_DEVICE_TABLE(of, db8500_thermal_match); |
| 228 | |
| 229 | static struct platform_driver db8500_thermal_driver = { |
| 230 | .driver = { |
| 231 | .name = "db8500-thermal", |
| 232 | .of_match_table = db8500_thermal_match, |
| 233 | }, |
| 234 | .probe = db8500_thermal_probe, |
| 235 | .suspend = db8500_thermal_suspend, |
| 236 | .resume = db8500_thermal_resume, |
| 237 | }; |
| 238 | |
| 239 | module_platform_driver(db8500_thermal_driver); |
| 240 | |
| 241 | MODULE_AUTHOR("Hongbo Zhang <hongbo.zhang@stericsson.com>"); |
| 242 | MODULE_DESCRIPTION("DB8500 thermal driver"); |
| 243 | MODULE_LICENSE("GPL"); |