diff options
Diffstat (limited to 'drivers/thermal/zx2967_thermal.c')
| -rw-r--r-- | drivers/thermal/zx2967_thermal.c | 258 |
1 files changed, 258 insertions, 0 deletions
diff --git a/drivers/thermal/zx2967_thermal.c b/drivers/thermal/zx2967_thermal.c new file mode 100644 index 000000000..6acce0bce --- /dev/null +++ b/drivers/thermal/zx2967_thermal.c @@ -0,0 +1,258 @@ +/* + * ZTE's zx2967 family thermal sensor driver + * + * Copyright (C) 2017 ZTE Ltd. + * + * Author: Baoyou Xie <baoyou.xie@linaro.org> + * + * License terms: GNU General Public License (GPL) version 2 + */ + +#include <linux/clk.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/iopoll.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/thermal.h> + +/* Power Mode: 0->low 1->high */ +#define ZX2967_THERMAL_POWER_MODE 0 +#define ZX2967_POWER_MODE_LOW 0 +#define ZX2967_POWER_MODE_HIGH 1 + +/* DCF Control Register */ +#define ZX2967_THERMAL_DCF 0x4 +#define ZX2967_DCF_EN BIT(1) +#define ZX2967_DCF_FREEZE BIT(0) + +/* Selection Register */ +#define ZX2967_THERMAL_SEL 0x8 + +/* Control Register */ +#define ZX2967_THERMAL_CTRL 0x10 + +#define ZX2967_THERMAL_READY BIT(12) +#define ZX2967_THERMAL_TEMP_MASK GENMASK(11, 0) +#define ZX2967_THERMAL_ID_MASK 0x18 +#define ZX2967_THERMAL_ID 0x10 + +#define ZX2967_GET_TEMP_TIMEOUT_US (100 * 1024) + +/** + * struct zx2967_thermal_priv - zx2967 thermal sensor private structure + * @tzd: struct thermal_zone_device where the sensor is registered + * @lock: prevents read sensor in parallel + * @clk_topcrm: topcrm clk structure + * @clk_apb: apb clk structure + * @regs: pointer to base address of the thermal sensor + */ + +struct zx2967_thermal_priv { + struct thermal_zone_device *tzd; + struct mutex lock; + struct clk *clk_topcrm; + struct clk *clk_apb; + void __iomem *regs; + struct device *dev; +}; + +static int zx2967_thermal_get_temp(void *data, int *temp) +{ + void __iomem *regs; + struct zx2967_thermal_priv *priv = data; + u32 val; + int ret; + + if (!priv->tzd) + return -EAGAIN; + + regs = priv->regs; + mutex_lock(&priv->lock); + writel_relaxed(ZX2967_POWER_MODE_LOW, + regs + ZX2967_THERMAL_POWER_MODE); + writel_relaxed(ZX2967_DCF_EN, regs + ZX2967_THERMAL_DCF); + + val = readl_relaxed(regs + ZX2967_THERMAL_SEL); + val &= ~ZX2967_THERMAL_ID_MASK; + val |= ZX2967_THERMAL_ID; + writel_relaxed(val, regs + ZX2967_THERMAL_SEL); + + /* + * Must wait for a while, surely it's a bit odd. + * otherwise temperature value we got has a few deviation, even if + * the THERMAL_READY bit is set. + */ + usleep_range(100, 300); + ret = readx_poll_timeout(readl, regs + ZX2967_THERMAL_CTRL, + val, val & ZX2967_THERMAL_READY, 300, + ZX2967_GET_TEMP_TIMEOUT_US); + if (ret) { + dev_err(priv->dev, "Thermal sensor data timeout\n"); + goto unlock; + } + + writel_relaxed(ZX2967_DCF_FREEZE | ZX2967_DCF_EN, + regs + ZX2967_THERMAL_DCF); + val = readl_relaxed(regs + ZX2967_THERMAL_CTRL) + & ZX2967_THERMAL_TEMP_MASK; + writel_relaxed(ZX2967_POWER_MODE_HIGH, + regs + ZX2967_THERMAL_POWER_MODE); + + /* + * Calculate temperature + * In dts, slope is multiplied by 1000. + */ + *temp = DIV_ROUND_CLOSEST(((s32)val + priv->tzd->tzp->offset) * 1000, + priv->tzd->tzp->slope); + +unlock: + mutex_unlock(&priv->lock); + return ret; +} + +static const struct thermal_zone_of_device_ops zx2967_of_thermal_ops = { + .get_temp = zx2967_thermal_get_temp, +}; + +static int zx2967_thermal_probe(struct platform_device *pdev) +{ + struct zx2967_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->regs = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(priv->regs)) + return PTR_ERR(priv->regs); + + priv->clk_topcrm = devm_clk_get(&pdev->dev, "topcrm"); + if (IS_ERR(priv->clk_topcrm)) { + ret = PTR_ERR(priv->clk_topcrm); + dev_err(&pdev->dev, "failed to get topcrm clock: %d\n", ret); + return ret; + } + + ret = clk_prepare_enable(priv->clk_topcrm); + if (ret) { + dev_err(&pdev->dev, "failed to enable topcrm clock: %d\n", + ret); + return ret; + } + + priv->clk_apb = devm_clk_get(&pdev->dev, "apb"); + if (IS_ERR(priv->clk_apb)) { + ret = PTR_ERR(priv->clk_apb); + dev_err(&pdev->dev, "failed to get apb clock: %d\n", ret); + goto disable_clk_topcrm; + } + + ret = clk_prepare_enable(priv->clk_apb); + if (ret) { + dev_err(&pdev->dev, "failed to enable apb clock: %d\n", + ret); + goto disable_clk_topcrm; + } + + mutex_init(&priv->lock); + priv->tzd = thermal_zone_of_sensor_register(&pdev->dev, + 0, priv, &zx2967_of_thermal_ops); + + if (IS_ERR(priv->tzd)) { + ret = PTR_ERR(priv->tzd); + dev_err(&pdev->dev, "failed to register sensor: %d\n", ret); + goto disable_clk_all; + } + + if (priv->tzd->tzp->slope == 0) { + thermal_zone_of_sensor_unregister(&pdev->dev, priv->tzd); + dev_err(&pdev->dev, "coefficients of sensor is invalid\n"); + ret = -EINVAL; + goto disable_clk_all; + } + + priv->dev = &pdev->dev; + platform_set_drvdata(pdev, priv); + + return 0; + +disable_clk_all: + clk_disable_unprepare(priv->clk_apb); +disable_clk_topcrm: + clk_disable_unprepare(priv->clk_topcrm); + return ret; +} + +static int zx2967_thermal_exit(struct platform_device *pdev) +{ + struct zx2967_thermal_priv *priv = platform_get_drvdata(pdev); + + thermal_zone_of_sensor_unregister(&pdev->dev, priv->tzd); + clk_disable_unprepare(priv->clk_topcrm); + clk_disable_unprepare(priv->clk_apb); + + return 0; +} + +static const struct of_device_id zx2967_thermal_id_table[] = { + { .compatible = "zte,zx296718-thermal" }, + {} +}; +MODULE_DEVICE_TABLE(of, zx2967_thermal_id_table); + +#ifdef CONFIG_PM_SLEEP +static int zx2967_thermal_suspend(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct zx2967_thermal_priv *priv = platform_get_drvdata(pdev); + + if (priv && priv->clk_topcrm) + clk_disable_unprepare(priv->clk_topcrm); + + if (priv && priv->clk_apb) + clk_disable_unprepare(priv->clk_apb); + + return 0; +} + +static int zx2967_thermal_resume(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct zx2967_thermal_priv *priv = platform_get_drvdata(pdev); + int error; + + error = clk_prepare_enable(priv->clk_topcrm); + if (error) + return error; + + error = clk_prepare_enable(priv->clk_apb); + if (error) { + clk_disable_unprepare(priv->clk_topcrm); + return error; + } + + return 0; +} +#endif + +static SIMPLE_DEV_PM_OPS(zx2967_thermal_pm_ops, + zx2967_thermal_suspend, zx2967_thermal_resume); + +static struct platform_driver zx2967_thermal_driver = { + .probe = zx2967_thermal_probe, + .remove = zx2967_thermal_exit, + .driver = { + .name = "zx2967_thermal", + .of_match_table = zx2967_thermal_id_table, + .pm = &zx2967_thermal_pm_ops, + }, +}; +module_platform_driver(zx2967_thermal_driver); + +MODULE_AUTHOR("Baoyou Xie <baoyou.xie@linaro.org>"); +MODULE_DESCRIPTION("ZTE zx2967 thermal driver"); +MODULE_LICENSE("GPL v2"); |