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