diff options
Diffstat (limited to 'drivers/thermal/db8500_thermal.c')
| -rw-r--r-- | drivers/thermal/db8500_thermal.c | 240 |
1 files changed, 240 insertions, 0 deletions
diff --git a/drivers/thermal/db8500_thermal.c b/drivers/thermal/db8500_thermal.c new file mode 100644 index 000000000..cb10e2806 --- /dev/null +++ b/drivers/thermal/db8500_thermal.c @@ -0,0 +1,240 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * db8500_thermal.c - DB8500 Thermal Management Implementation + * + * Copyright (C) 2012 ST-Ericsson + * Copyright (C) 2012-2019 Linaro Ltd. + * + * Authors: Hongbo Zhang, Linus Walleij + */ + +#include <linux/cpu_cooling.h> +#include <linux/interrupt.h> +#include <linux/mfd/dbx500-prcmu.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/thermal.h> + +#define PRCMU_DEFAULT_MEASURE_TIME 0xFFF +#define PRCMU_DEFAULT_LOW_TEMP 0 + +/** + * db8500_thermal_points - the interpolation points that trigger + * interrupts + */ +static const unsigned long db8500_thermal_points[] = { + 15000, + 20000, + 25000, + 30000, + 35000, + 40000, + 45000, + 50000, + 55000, + 60000, + 65000, + 70000, + 75000, + 80000, + /* + * This is where things start to get really bad for the + * SoC and the thermal zones should be set up to trigger + * critical temperature at 85000 mC so we don't get above + * this point. + */ + 85000, + 90000, + 95000, + 100000, +}; + +struct db8500_thermal_zone { + struct thermal_zone_device *tz; + unsigned long interpolated_temp; + unsigned int cur_index; +}; + +/* Callback to get current temperature */ +static int db8500_thermal_get_temp(struct thermal_zone_device *tz, int *temp) +{ + struct db8500_thermal_zone *th = tz->devdata; + + /* + * TODO: There is no PRCMU interface to get temperature data currently, + * so a pseudo temperature is returned , it works for thermal framework + * and this will be fixed when the PRCMU interface is available. + */ + *temp = th->interpolated_temp; + + return 0; +} + +static const struct thermal_zone_device_ops thdev_ops = { + .get_temp = db8500_thermal_get_temp, +}; + +static void db8500_thermal_update_config(struct db8500_thermal_zone *th, + unsigned int idx, + unsigned long next_low, + unsigned long next_high) +{ + prcmu_stop_temp_sense(); + + th->cur_index = idx; + th->interpolated_temp = (next_low + next_high)/2; + + /* + * The PRCMU accept absolute temperatures in celsius so divide + * down the millicelsius with 1000 + */ + prcmu_config_hotmon((u8)(next_low/1000), (u8)(next_high/1000)); + prcmu_start_temp_sense(PRCMU_DEFAULT_MEASURE_TIME); +} + +static irqreturn_t prcmu_low_irq_handler(int irq, void *irq_data) +{ + struct db8500_thermal_zone *th = irq_data; + unsigned int idx = th->cur_index; + unsigned long next_low, next_high; + + if (idx == 0) + /* Meaningless for thermal management, ignoring it */ + return IRQ_HANDLED; + + if (idx == 1) { + next_high = db8500_thermal_points[0]; + next_low = PRCMU_DEFAULT_LOW_TEMP; + } else { + next_high = db8500_thermal_points[idx - 1]; + next_low = db8500_thermal_points[idx - 2]; + } + idx -= 1; + + db8500_thermal_update_config(th, idx, next_low, next_high); + dev_dbg(&th->tz->device, + "PRCMU set max %ld, min %ld\n", next_high, next_low); + + thermal_zone_device_update(th->tz, THERMAL_EVENT_UNSPECIFIED); + + return IRQ_HANDLED; +} + +static irqreturn_t prcmu_high_irq_handler(int irq, void *irq_data) +{ + struct db8500_thermal_zone *th = irq_data; + unsigned int idx = th->cur_index; + unsigned long next_low, next_high; + int num_points = ARRAY_SIZE(db8500_thermal_points); + + if (idx < num_points - 1) { + next_high = db8500_thermal_points[idx+1]; + next_low = db8500_thermal_points[idx]; + idx += 1; + + db8500_thermal_update_config(th, idx, next_low, next_high); + + dev_dbg(&th->tz->device, + "PRCMU set max %ld, min %ld\n", next_high, next_low); + } else if (idx == num_points - 1) + /* So we roof out 1 degree over the max point */ + th->interpolated_temp = db8500_thermal_points[idx] + 1; + + thermal_zone_device_update(th->tz, THERMAL_EVENT_UNSPECIFIED); + + return IRQ_HANDLED; +} + +static int db8500_thermal_probe(struct platform_device *pdev) +{ + struct db8500_thermal_zone *th = NULL; + struct device *dev = &pdev->dev; + int low_irq, high_irq, ret = 0; + + th = devm_kzalloc(dev, sizeof(*th), GFP_KERNEL); + if (!th) + return -ENOMEM; + + low_irq = platform_get_irq_byname(pdev, "IRQ_HOTMON_LOW"); + if (low_irq < 0) + return low_irq; + + ret = devm_request_threaded_irq(dev, low_irq, NULL, + prcmu_low_irq_handler, IRQF_NO_SUSPEND | IRQF_ONESHOT, + "dbx500_temp_low", th); + if (ret < 0) { + dev_err(dev, "failed to allocate temp low irq\n"); + return ret; + } + + high_irq = platform_get_irq_byname(pdev, "IRQ_HOTMON_HIGH"); + if (high_irq < 0) + return high_irq; + + ret = devm_request_threaded_irq(dev, high_irq, NULL, + prcmu_high_irq_handler, IRQF_NO_SUSPEND | IRQF_ONESHOT, + "dbx500_temp_high", th); + if (ret < 0) { + dev_err(dev, "failed to allocate temp high irq\n"); + return ret; + } + + /* register of thermal sensor and get info from DT */ + th->tz = devm_thermal_of_zone_register(dev, 0, th, &thdev_ops); + if (IS_ERR(th->tz)) { + dev_err(dev, "register thermal zone sensor failed\n"); + return PTR_ERR(th->tz); + } + dev_info(dev, "thermal zone sensor registered\n"); + + /* Start measuring at the lowest point */ + db8500_thermal_update_config(th, 0, PRCMU_DEFAULT_LOW_TEMP, + db8500_thermal_points[0]); + + platform_set_drvdata(pdev, th); + + return 0; +} + +static int db8500_thermal_suspend(struct platform_device *pdev, + pm_message_t state) +{ + prcmu_stop_temp_sense(); + + return 0; +} + +static int db8500_thermal_resume(struct platform_device *pdev) +{ + struct db8500_thermal_zone *th = platform_get_drvdata(pdev); + + /* Resume and start measuring at the lowest point */ + db8500_thermal_update_config(th, 0, PRCMU_DEFAULT_LOW_TEMP, + db8500_thermal_points[0]); + + return 0; +} + +static const struct of_device_id db8500_thermal_match[] = { + { .compatible = "stericsson,db8500-thermal" }, + {}, +}; +MODULE_DEVICE_TABLE(of, db8500_thermal_match); + +static struct platform_driver db8500_thermal_driver = { + .driver = { + .name = "db8500-thermal", + .of_match_table = of_match_ptr(db8500_thermal_match), + }, + .probe = db8500_thermal_probe, + .suspend = db8500_thermal_suspend, + .resume = db8500_thermal_resume, +}; + +module_platform_driver(db8500_thermal_driver); + +MODULE_AUTHOR("Hongbo Zhang <hongbo.zhang@stericsson.com>"); +MODULE_DESCRIPTION("DB8500 thermal driver"); +MODULE_LICENSE("GPL"); |