1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * ZTE's zx2967 family thermal sensor driver
  4 *
  5 * Copyright (C) 2017 ZTE Ltd.
  6 *
  7 * Author: Baoyou Xie <baoyou.xie@linaro.org>
  8 */
  9
 10#include <linux/clk.h>
 11#include <linux/device.h>
 12#include <linux/err.h>
 13#include <linux/iopoll.h>
 14#include <linux/module.h>
 15#include <linux/platform_device.h>
 16#include <linux/thermal.h>
 17
 18/* Power Mode: 0->low 1->high */
 19#define ZX2967_THERMAL_POWER_MODE	0
 20#define ZX2967_POWER_MODE_LOW		0
 21#define ZX2967_POWER_MODE_HIGH		1
 22
 23/* DCF Control Register */
 24#define ZX2967_THERMAL_DCF		0x4
 25#define ZX2967_DCF_EN			BIT(1)
 26#define ZX2967_DCF_FREEZE		BIT(0)
 27
 28/* Selection Register */
 29#define ZX2967_THERMAL_SEL		0x8
 30
 31/* Control Register */
 32#define ZX2967_THERMAL_CTRL		0x10
 33
 34#define ZX2967_THERMAL_READY		BIT(12)
 35#define ZX2967_THERMAL_TEMP_MASK	GENMASK(11, 0)
 36#define ZX2967_THERMAL_ID_MASK		0x18
 37#define ZX2967_THERMAL_ID		0x10
 38
 39#define ZX2967_GET_TEMP_TIMEOUT_US	(100 * 1024)
 40
 41/**
 42 * struct zx2967_thermal_priv - zx2967 thermal sensor private structure
 43 * @tzd: struct thermal_zone_device where the sensor is registered
 44 * @lock: prevents read sensor in parallel
 45 * @clk_topcrm: topcrm clk structure
 46 * @clk_apb: apb clk structure
 47 * @regs: pointer to base address of the thermal sensor
 48 * @dev: struct device pointer
 49 */
 50
 51struct zx2967_thermal_priv {
 52	struct thermal_zone_device	*tzd;
 53	struct mutex			lock;
 54	struct clk			*clk_topcrm;
 55	struct clk			*clk_apb;
 56	void __iomem			*regs;
 57	struct device			*dev;
 58};
 59
 60static int zx2967_thermal_get_temp(void *data, int *temp)
 61{
 62	void __iomem *regs;
 63	struct zx2967_thermal_priv *priv = data;
 64	u32 val;
 65	int ret;
 66
 67	if (!priv->tzd)
 68		return -EAGAIN;
 69
 70	regs = priv->regs;
 71	mutex_lock(&priv->lock);
 72	writel_relaxed(ZX2967_POWER_MODE_LOW,
 73		       regs + ZX2967_THERMAL_POWER_MODE);
 74	writel_relaxed(ZX2967_DCF_EN, regs + ZX2967_THERMAL_DCF);
 75
 76	val = readl_relaxed(regs + ZX2967_THERMAL_SEL);
 77	val &= ~ZX2967_THERMAL_ID_MASK;
 78	val |= ZX2967_THERMAL_ID;
 79	writel_relaxed(val, regs + ZX2967_THERMAL_SEL);
 80
 81	/*
 82	 * Must wait for a while, surely it's a bit odd.
 83	 * otherwise temperature value we got has a few deviation, even if
 84	 * the THERMAL_READY bit is set.
 85	 */
 86	usleep_range(100, 300);
 87	ret = readx_poll_timeout(readl, regs + ZX2967_THERMAL_CTRL,
 88				 val, val & ZX2967_THERMAL_READY, 300,
 89				 ZX2967_GET_TEMP_TIMEOUT_US);
 90	if (ret) {
 91		dev_err(priv->dev, "Thermal sensor data timeout\n");
 92		goto unlock;
 93	}
 94
 95	writel_relaxed(ZX2967_DCF_FREEZE | ZX2967_DCF_EN,
 96		       regs + ZX2967_THERMAL_DCF);
 97	val = readl_relaxed(regs + ZX2967_THERMAL_CTRL)
 98			 & ZX2967_THERMAL_TEMP_MASK;
 99	writel_relaxed(ZX2967_POWER_MODE_HIGH,
100		       regs + ZX2967_THERMAL_POWER_MODE);
101
102	/*
103	 * Calculate temperature
104	 * In dts, slope is multiplied by 1000.
105	 */
106	*temp = DIV_ROUND_CLOSEST(((s32)val + priv->tzd->tzp->offset) * 1000,
107				  priv->tzd->tzp->slope);
108
109unlock:
110	mutex_unlock(&priv->lock);
111	return ret;
112}
113
114static const struct thermal_zone_of_device_ops zx2967_of_thermal_ops = {
115	.get_temp = zx2967_thermal_get_temp,
116};
117
118static int zx2967_thermal_probe(struct platform_device *pdev)
119{
120	struct zx2967_thermal_priv *priv;
121	struct resource *res;
122	int ret;
123
124	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
125	if (!priv)
126		return -ENOMEM;
127
128	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
129	priv->regs = devm_ioremap_resource(&pdev->dev, res);
130	if (IS_ERR(priv->regs))
131		return PTR_ERR(priv->regs);
132
133	priv->clk_topcrm = devm_clk_get(&pdev->dev, "topcrm");
134	if (IS_ERR(priv->clk_topcrm)) {
135		ret = PTR_ERR(priv->clk_topcrm);
136		dev_err(&pdev->dev, "failed to get topcrm clock: %d\n", ret);
137		return ret;
138	}
139
140	ret = clk_prepare_enable(priv->clk_topcrm);
141	if (ret) {
142		dev_err(&pdev->dev, "failed to enable topcrm clock: %d\n",
143			ret);
144		return ret;
145	}
146
147	priv->clk_apb = devm_clk_get(&pdev->dev, "apb");
148	if (IS_ERR(priv->clk_apb)) {
149		ret = PTR_ERR(priv->clk_apb);
150		dev_err(&pdev->dev, "failed to get apb clock: %d\n", ret);
151		goto disable_clk_topcrm;
152	}
153
154	ret = clk_prepare_enable(priv->clk_apb);
155	if (ret) {
156		dev_err(&pdev->dev, "failed to enable apb clock: %d\n",
157			ret);
158		goto disable_clk_topcrm;
159	}
160
161	mutex_init(&priv->lock);
162	priv->tzd = thermal_zone_of_sensor_register(&pdev->dev,
163					0, priv, &zx2967_of_thermal_ops);
164
165	if (IS_ERR(priv->tzd)) {
166		ret = PTR_ERR(priv->tzd);
167		dev_err(&pdev->dev, "failed to register sensor: %d\n", ret);
168		goto disable_clk_all;
169	}
170
171	if (priv->tzd->tzp->slope == 0) {
172		thermal_zone_of_sensor_unregister(&pdev->dev, priv->tzd);
173		dev_err(&pdev->dev, "coefficients of sensor is invalid\n");
174		ret = -EINVAL;
175		goto disable_clk_all;
176	}
177
178	priv->dev = &pdev->dev;
179	platform_set_drvdata(pdev, priv);
180
181	return 0;
182
183disable_clk_all:
184	clk_disable_unprepare(priv->clk_apb);
185disable_clk_topcrm:
186	clk_disable_unprepare(priv->clk_topcrm);
187	return ret;
188}
189
190static int zx2967_thermal_exit(struct platform_device *pdev)
191{
192	struct zx2967_thermal_priv *priv = platform_get_drvdata(pdev);
193
194	thermal_zone_of_sensor_unregister(&pdev->dev, priv->tzd);
195	clk_disable_unprepare(priv->clk_topcrm);
196	clk_disable_unprepare(priv->clk_apb);
197
198	return 0;
199}
200
201static const struct of_device_id zx2967_thermal_id_table[] = {
202	{ .compatible = "zte,zx296718-thermal" },
203	{}
204};
205MODULE_DEVICE_TABLE(of, zx2967_thermal_id_table);
206
207#ifdef CONFIG_PM_SLEEP
208static int zx2967_thermal_suspend(struct device *dev)
209{
210	struct zx2967_thermal_priv *priv = dev_get_drvdata(dev);
211
212	if (priv && priv->clk_topcrm)
213		clk_disable_unprepare(priv->clk_topcrm);
214
215	if (priv && priv->clk_apb)
216		clk_disable_unprepare(priv->clk_apb);
217
218	return 0;
219}
220
221static int zx2967_thermal_resume(struct device *dev)
222{
223	struct zx2967_thermal_priv *priv = dev_get_drvdata(dev);
224	int error;
225
226	error = clk_prepare_enable(priv->clk_topcrm);
227	if (error)
228		return error;
229
230	error = clk_prepare_enable(priv->clk_apb);
231	if (error) {
232		clk_disable_unprepare(priv->clk_topcrm);
233		return error;
234	}
235
236	return 0;
237}
238#endif
239
240static SIMPLE_DEV_PM_OPS(zx2967_thermal_pm_ops,
241			 zx2967_thermal_suspend, zx2967_thermal_resume);
242
243static struct platform_driver zx2967_thermal_driver = {
244	.probe = zx2967_thermal_probe,
245	.remove = zx2967_thermal_exit,
246	.driver = {
247		.name = "zx2967_thermal",
248		.of_match_table = zx2967_thermal_id_table,
249		.pm = &zx2967_thermal_pm_ops,
250	},
251};
252module_platform_driver(zx2967_thermal_driver);
253
254MODULE_AUTHOR("Baoyou Xie <baoyou.xie@linaro.org>");
255MODULE_DESCRIPTION("ZTE zx2967 thermal driver");
256MODULE_LICENSE("GPL v2");