/* * ZTE's zx2967 family thermal sensor driver * * Copyright (C) 2017 ZTE Ltd. * * Author: Baoyou Xie * * License terms: GNU General Public License (GPL) version 2 */ #include #include #include #include #include #include #include /* 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 "); MODULE_DESCRIPTION("ZTE zx2967 thermal driver"); MODULE_LICENSE("GPL v2");