diff options
Diffstat (limited to 'drivers/thermal/da9062-thermal.c')
| -rw-r--r-- | drivers/thermal/da9062-thermal.c | 315 |
1 files changed, 315 insertions, 0 deletions
diff --git a/drivers/thermal/da9062-thermal.c b/drivers/thermal/da9062-thermal.c new file mode 100644 index 000000000000..dd8dd947b7f0 --- /dev/null +++ b/drivers/thermal/da9062-thermal.c @@ -0,0 +1,315 @@ +/* + * Thermal device driver for DA9062 and DA9061 + * Copyright (C) 2017 Dialog Semiconductor + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +/* When over-temperature is reached, an interrupt from the device will be + * triggered. Following this event the interrupt will be disabled and + * periodic transmission of uevents (HOT trip point) should define the + * first level of temperature supervision. It is expected that any final + * implementation of the thermal driver will include a .notify() function + * to implement these uevents to userspace. + * + * These uevents are intended to indicate non-invasive temperature control + * of the system, where the necessary measures for cooling are the + * responsibility of the host software. Once the temperature falls again, + * the IRQ is re-enabled so the start of a new over-temperature event can + * be detected without constant software monitoring. + */ + +#include <linux/errno.h> +#include <linux/interrupt.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> +#include <linux/thermal.h> +#include <linux/workqueue.h> + +#include <linux/mfd/da9062/core.h> +#include <linux/mfd/da9062/registers.h> + +/* Minimum, maximum and default polling millisecond periods are provided + * here as an example. It is expected that any final implementation to also + * include a modification of these settings to match the required + * application. + */ +#define DA9062_DEFAULT_POLLING_MS_PERIOD 3000 +#define DA9062_MAX_POLLING_MS_PERIOD 10000 +#define DA9062_MIN_POLLING_MS_PERIOD 1000 + +#define DA9062_MILLI_CELSIUS(t) ((t) * 1000) + +struct da9062_thermal_config { + const char *name; +}; + +struct da9062_thermal { + struct da9062 *hw; + struct delayed_work work; + struct thermal_zone_device *zone; + enum thermal_device_mode mode; + struct mutex lock; /* protection for da9062_thermal temperature */ + int temperature; + int irq; + const struct da9062_thermal_config *config; + struct device *dev; +}; + +static void da9062_thermal_poll_on(struct work_struct *work) +{ + struct da9062_thermal *thermal = container_of(work, + struct da9062_thermal, + work.work); + unsigned long delay; + unsigned int val; + int ret; + + /* clear E_TEMP */ + ret = regmap_write(thermal->hw->regmap, + DA9062AA_EVENT_B, + DA9062AA_E_TEMP_MASK); + if (ret < 0) { + dev_err(thermal->dev, + "Cannot clear the TJUNC temperature status\n"); + goto err_enable_irq; + } + + /* Now read E_TEMP again: it is acting like a status bit. + * If over-temperature, then this status will be true. + * If not over-temperature, this status will be false. + */ + ret = regmap_read(thermal->hw->regmap, + DA9062AA_EVENT_B, + &val); + if (ret < 0) { + dev_err(thermal->dev, + "Cannot check the TJUNC temperature status\n"); + goto err_enable_irq; + } + + if (val & DA9062AA_E_TEMP_MASK) { + mutex_lock(&thermal->lock); + thermal->temperature = DA9062_MILLI_CELSIUS(125); + mutex_unlock(&thermal->lock); + thermal_zone_device_update(thermal->zone, + THERMAL_EVENT_UNSPECIFIED); + + delay = msecs_to_jiffies(thermal->zone->passive_delay); + schedule_delayed_work(&thermal->work, delay); + return; + } + + mutex_lock(&thermal->lock); + thermal->temperature = DA9062_MILLI_CELSIUS(0); + mutex_unlock(&thermal->lock); + thermal_zone_device_update(thermal->zone, + THERMAL_EVENT_UNSPECIFIED); + +err_enable_irq: + enable_irq(thermal->irq); +} + +static irqreturn_t da9062_thermal_irq_handler(int irq, void *data) +{ + struct da9062_thermal *thermal = data; + + disable_irq_nosync(thermal->irq); + schedule_delayed_work(&thermal->work, 0); + + return IRQ_HANDLED; +} + +static int da9062_thermal_get_mode(struct thermal_zone_device *z, + enum thermal_device_mode *mode) +{ + struct da9062_thermal *thermal = z->devdata; + *mode = thermal->mode; + return 0; +} + +static int da9062_thermal_get_trip_type(struct thermal_zone_device *z, + int trip, + enum thermal_trip_type *type) +{ + struct da9062_thermal *thermal = z->devdata; + + switch (trip) { + case 0: + *type = THERMAL_TRIP_HOT; + break; + default: + dev_err(thermal->dev, + "Driver does not support more than 1 trip-wire\n"); + return -EINVAL; + } + + return 0; +} + +static int da9062_thermal_get_trip_temp(struct thermal_zone_device *z, + int trip, + int *temp) +{ + struct da9062_thermal *thermal = z->devdata; + + switch (trip) { + case 0: + *temp = DA9062_MILLI_CELSIUS(125); + break; + default: + dev_err(thermal->dev, + "Driver does not support more than 1 trip-wire\n"); + return -EINVAL; + } + + return 0; +} + +static int da9062_thermal_get_temp(struct thermal_zone_device *z, + int *temp) +{ + struct da9062_thermal *thermal = z->devdata; + + mutex_lock(&thermal->lock); + *temp = thermal->temperature; + mutex_unlock(&thermal->lock); + + return 0; +} + +static struct thermal_zone_device_ops da9062_thermal_ops = { + .get_temp = da9062_thermal_get_temp, + .get_mode = da9062_thermal_get_mode, + .get_trip_type = da9062_thermal_get_trip_type, + .get_trip_temp = da9062_thermal_get_trip_temp, +}; + +static const struct da9062_thermal_config da9062_config = { + .name = "da9062-thermal", +}; + +static const struct of_device_id da9062_compatible_reg_id_table[] = { + { .compatible = "dlg,da9062-thermal", .data = &da9062_config }, + { }, +}; + +MODULE_DEVICE_TABLE(of, da9062_compatible_reg_id_table); + +static int da9062_thermal_probe(struct platform_device *pdev) +{ + struct da9062 *chip = dev_get_drvdata(pdev->dev.parent); + struct da9062_thermal *thermal; + unsigned int pp_tmp = DA9062_DEFAULT_POLLING_MS_PERIOD; + const struct of_device_id *match; + int ret = 0; + + match = of_match_node(da9062_compatible_reg_id_table, + pdev->dev.of_node); + if (!match) + return -ENXIO; + + if (pdev->dev.of_node) { + if (!of_property_read_u32(pdev->dev.of_node, + "polling-delay-passive", + &pp_tmp)) { + if (pp_tmp < DA9062_MIN_POLLING_MS_PERIOD || + pp_tmp > DA9062_MAX_POLLING_MS_PERIOD) { + dev_warn(&pdev->dev, + "Out-of-range polling period %d ms\n", + pp_tmp); + pp_tmp = DA9062_DEFAULT_POLLING_MS_PERIOD; + } + } + } + + thermal = devm_kzalloc(&pdev->dev, sizeof(struct da9062_thermal), + GFP_KERNEL); + if (!thermal) { + ret = -ENOMEM; + goto err; + } + + thermal->config = match->data; + thermal->hw = chip; + thermal->mode = THERMAL_DEVICE_ENABLED; + thermal->dev = &pdev->dev; + + INIT_DELAYED_WORK(&thermal->work, da9062_thermal_poll_on); + mutex_init(&thermal->lock); + + thermal->zone = thermal_zone_device_register(thermal->config->name, + 1, 0, thermal, + &da9062_thermal_ops, NULL, pp_tmp, + 0); + if (IS_ERR(thermal->zone)) { + dev_err(&pdev->dev, "Cannot register thermal zone device\n"); + ret = PTR_ERR(thermal->zone); + goto err; + } + + dev_dbg(&pdev->dev, + "TJUNC temperature polling period set at %d ms\n", + thermal->zone->passive_delay); + + ret = platform_get_irq_byname(pdev, "THERMAL"); + if (ret < 0) { + dev_err(&pdev->dev, "Failed to get platform IRQ.\n"); + goto err_zone; + } + thermal->irq = ret; + + ret = request_threaded_irq(thermal->irq, NULL, + da9062_thermal_irq_handler, + IRQF_TRIGGER_LOW | IRQF_ONESHOT, + "THERMAL", thermal); + if (ret) { + dev_err(&pdev->dev, + "Failed to request thermal device IRQ.\n"); + goto err_zone; + } + + platform_set_drvdata(pdev, thermal); + return 0; + +err_zone: + thermal_zone_device_unregister(thermal->zone); +err: + return ret; +} + +static int da9062_thermal_remove(struct platform_device *pdev) +{ + struct da9062_thermal *thermal = platform_get_drvdata(pdev); + + free_irq(thermal->irq, thermal); + cancel_delayed_work_sync(&thermal->work); + thermal_zone_device_unregister(thermal->zone); + return 0; +} + +static struct platform_driver da9062_thermal_driver = { + .probe = da9062_thermal_probe, + .remove = da9062_thermal_remove, + .driver = { + .name = "da9062-thermal", + .of_match_table = da9062_compatible_reg_id_table, + }, +}; + +module_platform_driver(da9062_thermal_driver); + +MODULE_AUTHOR("Steve Twiss"); +MODULE_DESCRIPTION("Thermal TJUNC device driver for Dialog DA9062 and DA9061"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:da9062-thermal"); |