| /* |
| * 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 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"); |