diff options
Diffstat (limited to 'drivers/thermal/dove_thermal.c')
| -rw-r--r-- | drivers/thermal/dove_thermal.c | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/drivers/thermal/dove_thermal.c b/drivers/thermal/dove_thermal.c new file mode 100644 index 000000000..73182eb94 --- /dev/null +++ b/drivers/thermal/dove_thermal.c @@ -0,0 +1,192 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Dove thermal sensor driver + * + * Copyright (C) 2013 Andrew Lunn <andrew@lunn.ch> + */ +#include <linux/device.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/of.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/thermal.h> + +#define DOVE_THERMAL_TEMP_OFFSET 1 +#define DOVE_THERMAL_TEMP_MASK 0x1FF + +/* Dove Thermal Manager Control and Status Register */ +#define PMU_TM_DISABLE_OFFS 0 +#define PMU_TM_DISABLE_MASK (0x1 << PMU_TM_DISABLE_OFFS) + +/* Dove Theraml Diode Control 0 Register */ +#define PMU_TDC0_SW_RST_MASK (0x1 << 1) +#define PMU_TDC0_SEL_VCAL_OFFS 5 +#define PMU_TDC0_SEL_VCAL_MASK (0x3 << PMU_TDC0_SEL_VCAL_OFFS) +#define PMU_TDC0_REF_CAL_CNT_OFFS 11 +#define PMU_TDC0_REF_CAL_CNT_MASK (0x1FF << PMU_TDC0_REF_CAL_CNT_OFFS) +#define PMU_TDC0_AVG_NUM_OFFS 25 +#define PMU_TDC0_AVG_NUM_MASK (0x7 << PMU_TDC0_AVG_NUM_OFFS) + +/* Dove Thermal Diode Control 1 Register */ +#define PMU_TEMP_DIOD_CTRL1_REG 0x04 +#define PMU_TDC1_TEMP_VALID_MASK (0x1 << 10) + +/* Dove Thermal Sensor Dev Structure */ +struct dove_thermal_priv { + void __iomem *sensor; + void __iomem *control; +}; + +static int dove_init_sensor(const struct dove_thermal_priv *priv) +{ + u32 reg; + u32 i; + + /* Configure the Diode Control Register #0 */ + reg = readl_relaxed(priv->control); + + /* Use average of 2 */ + reg &= ~PMU_TDC0_AVG_NUM_MASK; + reg |= (0x1 << PMU_TDC0_AVG_NUM_OFFS); + + /* Reference calibration value */ + reg &= ~PMU_TDC0_REF_CAL_CNT_MASK; + reg |= (0x0F1 << PMU_TDC0_REF_CAL_CNT_OFFS); + + /* Set the high level reference for calibration */ + reg &= ~PMU_TDC0_SEL_VCAL_MASK; + reg |= (0x2 << PMU_TDC0_SEL_VCAL_OFFS); + writel(reg, priv->control); + + /* Reset the sensor */ + reg = readl_relaxed(priv->control); + writel((reg | PMU_TDC0_SW_RST_MASK), priv->control); + writel(reg, priv->control); + + /* Enable the sensor */ + reg = readl_relaxed(priv->sensor); + reg &= ~PMU_TM_DISABLE_MASK; + writel(reg, priv->sensor); + + /* Poll the sensor for the first reading */ + for (i = 0; i < 1000000; i++) { + reg = readl_relaxed(priv->sensor); + if (reg & DOVE_THERMAL_TEMP_MASK) + break; + } + + if (i == 1000000) + return -EIO; + + return 0; +} + +static int dove_get_temp(struct thermal_zone_device *thermal, + int *temp) +{ + unsigned long reg; + struct dove_thermal_priv *priv = thermal->devdata; + + /* Valid check */ + reg = readl_relaxed(priv->control + PMU_TEMP_DIOD_CTRL1_REG); + if ((reg & PMU_TDC1_TEMP_VALID_MASK) == 0x0) { + dev_err(&thermal->device, + "Temperature sensor reading not valid\n"); + return -EIO; + } + + /* + * Calculate temperature. According to Marvell internal + * documentation the formula for this is: + * Celsius = (322-reg)/1.3625 + */ + reg = readl_relaxed(priv->sensor); + reg = (reg >> DOVE_THERMAL_TEMP_OFFSET) & DOVE_THERMAL_TEMP_MASK; + *temp = ((3220000000UL - (10000000UL * reg)) / 13625); + + return 0; +} + +static struct thermal_zone_device_ops ops = { + .get_temp = dove_get_temp, +}; + +static const struct of_device_id dove_thermal_id_table[] = { + { .compatible = "marvell,dove-thermal" }, + {} +}; + +static int dove_thermal_probe(struct platform_device *pdev) +{ + struct thermal_zone_device *thermal = NULL; + struct dove_thermal_priv *priv; + struct resource *res; + int ret; + + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + priv->sensor = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(priv->sensor)) + return PTR_ERR(priv->sensor); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 1); + priv->control = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(priv->control)) + return PTR_ERR(priv->control); + + ret = dove_init_sensor(priv); + if (ret) { + dev_err(&pdev->dev, "Failed to initialize sensor\n"); + return ret; + } + + thermal = thermal_zone_device_register("dove_thermal", 0, 0, + priv, &ops, NULL, 0, 0); + if (IS_ERR(thermal)) { + dev_err(&pdev->dev, + "Failed to register thermal zone device\n"); + return PTR_ERR(thermal); + } + + ret = thermal_zone_device_enable(thermal); + if (ret) { + thermal_zone_device_unregister(thermal); + return ret; + } + + platform_set_drvdata(pdev, thermal); + + return 0; +} + +static int dove_thermal_exit(struct platform_device *pdev) +{ + struct thermal_zone_device *dove_thermal = + platform_get_drvdata(pdev); + + thermal_zone_device_unregister(dove_thermal); + + return 0; +} + +MODULE_DEVICE_TABLE(of, dove_thermal_id_table); + +static struct platform_driver dove_thermal_driver = { + .probe = dove_thermal_probe, + .remove = dove_thermal_exit, + .driver = { + .name = "dove_thermal", + .of_match_table = dove_thermal_id_table, + }, +}; + +module_platform_driver(dove_thermal_driver); + +MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>"); +MODULE_DESCRIPTION("Dove thermal driver"); +MODULE_LICENSE("GPL"); |