1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Renesas RZ/G2L TSU Thermal Sensor Driver
4 *
5 * Copyright (C) 2021 Renesas Electronics Corporation
6 */
7#include <linux/delay.h>
8#include <linux/err.h>
9#include <linux/io.h>
10#include <linux/iopoll.h>
11#include <linux/math.h>
12#include <linux/mod_devicetable.h>
13#include <linux/module.h>
14#include <linux/platform_device.h>
15#include <linux/pm_runtime.h>
16#include <linux/reset.h>
17#include <linux/thermal.h>
18#include <linux/units.h>
19
20#include "thermal_hwmon.h"
21
22#define CTEMP_MASK 0xFFF
23
24/* default calibration values, if FUSE values are missing */
25#define SW_CALIB0_VAL 3148
26#define SW_CALIB1_VAL 503
27
28/* Register offsets */
29#define TSU_SM 0x00
30#define TSU_ST 0x04
31#define TSU_SAD 0x0C
32#define TSU_SS 0x10
33
34#define OTPTSUTRIM_REG(n) (0x18 + ((n) * 0x4))
35#define OTPTSUTRIM_EN_MASK BIT(31)
36#define OTPTSUTRIM_MASK GENMASK(11, 0)
37
38/* Sensor Mode Register(TSU_SM) */
39#define TSU_SM_EN_TS BIT(0)
40#define TSU_SM_ADC_EN_TS BIT(1)
41#define TSU_SM_NORMAL_MODE (TSU_SM_EN_TS | TSU_SM_ADC_EN_TS)
42
43/* TSU_ST bits */
44#define TSU_ST_START BIT(0)
45
46#define TSU_SS_CONV_RUNNING BIT(0)
47
48#define TS_CODE_AVE_SCALE(x) ((x) * 1000000)
49#define MCELSIUS(temp) ((temp) * MILLIDEGREE_PER_DEGREE)
50#define TS_CODE_CAP_TIMES 8 /* Total number of ADC data samples */
51
52#define RZG2L_THERMAL_GRAN 500 /* milli Celsius */
53#define RZG2L_TSU_SS_TIMEOUT_US 1000
54
55#define CURVATURE_CORRECTION_CONST 13
56
57struct rzg2l_thermal_priv {
58 struct device *dev;
59 void __iomem *base;
60 struct thermal_zone_device *zone;
61 struct reset_control *rstc;
62 u32 calib0, calib1;
63};
64
65static inline u32 rzg2l_thermal_read(struct rzg2l_thermal_priv *priv, u32 reg)
66{
67 return ioread32(priv->base + reg);
68}
69
70static inline void rzg2l_thermal_write(struct rzg2l_thermal_priv *priv, u32 reg,
71 u32 data)
72{
73 iowrite32(data, priv->base + reg);
74}
75
76static int rzg2l_thermal_get_temp(struct thermal_zone_device *tz, int *temp)
77{
78 struct rzg2l_thermal_priv *priv = thermal_zone_device_priv(tzd: tz);
79 u32 result = 0, dsensor, ts_code_ave;
80 int val, i;
81
82 for (i = 0; i < TS_CODE_CAP_TIMES ; i++) {
83 /*
84 * TSU repeats measurement at 20 microseconds intervals and
85 * automatically updates the results of measurement. As per
86 * the HW manual for measuring temperature we need to read 8
87 * values consecutively and then take the average.
88 * ts_code_ave = (ts_code[0] + ⋯ + ts_code[7]) / 8
89 */
90 result += rzg2l_thermal_read(priv, TSU_SAD) & CTEMP_MASK;
91 usleep_range(min: 20, max: 30);
92 }
93
94 ts_code_ave = result / TS_CODE_CAP_TIMES;
95
96 /*
97 * Calculate actual sensor value by applying curvature correction formula
98 * dsensor = ts_code_ave / (1 + ts_code_ave * 0.000013). Here we are doing
99 * integer calculation by scaling all the values by 1000000.
100 */
101 dsensor = TS_CODE_AVE_SCALE(ts_code_ave) /
102 (TS_CODE_AVE_SCALE(1) + (ts_code_ave * CURVATURE_CORRECTION_CONST));
103
104 /*
105 * The temperature Tj is calculated by the formula
106 * Tj = (dsensor − calib1) * 165/ (calib0 − calib1) − 40
107 * where calib0 and calib1 are the calibration values.
108 */
109 val = ((dsensor - priv->calib1) * (MCELSIUS(165) /
110 (priv->calib0 - priv->calib1))) - MCELSIUS(40);
111
112 *temp = roundup(val, RZG2L_THERMAL_GRAN);
113
114 return 0;
115}
116
117static const struct thermal_zone_device_ops rzg2l_tz_of_ops = {
118 .get_temp = rzg2l_thermal_get_temp,
119};
120
121static int rzg2l_thermal_init(struct rzg2l_thermal_priv *priv)
122{
123 u32 reg_val;
124
125 rzg2l_thermal_write(priv, TSU_SM, TSU_SM_NORMAL_MODE);
126 rzg2l_thermal_write(priv, TSU_ST, data: 0);
127
128 /*
129 * Before setting the START bit, TSU should be in normal operating
130 * mode. As per the HW manual, it will take 60 µs to place the TSU
131 * into normal operating mode.
132 */
133 usleep_range(min: 60, max: 80);
134
135 reg_val = rzg2l_thermal_read(priv, TSU_ST);
136 reg_val |= TSU_ST_START;
137 rzg2l_thermal_write(priv, TSU_ST, data: reg_val);
138
139 return readl_poll_timeout(priv->base + TSU_SS, reg_val,
140 reg_val == TSU_SS_CONV_RUNNING, 50,
141 RZG2L_TSU_SS_TIMEOUT_US);
142}
143
144static void rzg2l_thermal_reset_assert_pm_disable_put(struct platform_device *pdev)
145{
146 struct rzg2l_thermal_priv *priv = dev_get_drvdata(dev: &pdev->dev);
147
148 pm_runtime_put(dev: &pdev->dev);
149 pm_runtime_disable(dev: &pdev->dev);
150 reset_control_assert(rstc: priv->rstc);
151}
152
153static void rzg2l_thermal_remove(struct platform_device *pdev)
154{
155 struct rzg2l_thermal_priv *priv = dev_get_drvdata(dev: &pdev->dev);
156
157 thermal_remove_hwmon_sysfs(tz: priv->zone);
158 rzg2l_thermal_reset_assert_pm_disable_put(pdev);
159}
160
161static int rzg2l_thermal_probe(struct platform_device *pdev)
162{
163 struct thermal_zone_device *zone;
164 struct rzg2l_thermal_priv *priv;
165 struct device *dev = &pdev->dev;
166 int ret;
167
168 priv = devm_kzalloc(dev, size: sizeof(*priv), GFP_KERNEL);
169 if (!priv)
170 return -ENOMEM;
171
172 priv->base = devm_platform_ioremap_resource(pdev, index: 0);
173 if (IS_ERR(ptr: priv->base))
174 return PTR_ERR(ptr: priv->base);
175
176 priv->dev = dev;
177 priv->rstc = devm_reset_control_get_exclusive(dev, NULL);
178 if (IS_ERR(ptr: priv->rstc))
179 return dev_err_probe(dev, err: PTR_ERR(ptr: priv->rstc),
180 fmt: "failed to get cpg reset");
181
182 ret = reset_control_deassert(rstc: priv->rstc);
183 if (ret)
184 return dev_err_probe(dev, err: ret, fmt: "failed to deassert");
185
186 pm_runtime_enable(dev);
187 pm_runtime_get_sync(dev);
188
189 priv->calib0 = rzg2l_thermal_read(priv, OTPTSUTRIM_REG(0));
190 if (priv->calib0 & OTPTSUTRIM_EN_MASK)
191 priv->calib0 &= OTPTSUTRIM_MASK;
192 else
193 priv->calib0 = SW_CALIB0_VAL;
194
195 priv->calib1 = rzg2l_thermal_read(priv, OTPTSUTRIM_REG(1));
196 if (priv->calib1 & OTPTSUTRIM_EN_MASK)
197 priv->calib1 &= OTPTSUTRIM_MASK;
198 else
199 priv->calib1 = SW_CALIB1_VAL;
200
201 platform_set_drvdata(pdev, data: priv);
202 ret = rzg2l_thermal_init(priv);
203 if (ret) {
204 dev_err(dev, "Failed to start TSU");
205 goto err;
206 }
207
208 zone = devm_thermal_of_zone_register(dev, id: 0, data: priv,
209 ops: &rzg2l_tz_of_ops);
210 if (IS_ERR(ptr: zone)) {
211 dev_err(dev, "Can't register thermal zone");
212 ret = PTR_ERR(ptr: zone);
213 goto err;
214 }
215
216 priv->zone = zone;
217 ret = thermal_add_hwmon_sysfs(tz: priv->zone);
218 if (ret)
219 goto err;
220
221 dev_dbg(dev, "TSU probed with %s calibration values",
222 rzg2l_thermal_read(priv, OTPTSUTRIM_REG(0)) ? "hw" : "sw");
223
224 return 0;
225
226err:
227 rzg2l_thermal_reset_assert_pm_disable_put(pdev);
228 return ret;
229}
230
231static const struct of_device_id rzg2l_thermal_dt_ids[] = {
232 { .compatible = "renesas,rzg2l-tsu", },
233 { /* sentinel */ }
234};
235MODULE_DEVICE_TABLE(of, rzg2l_thermal_dt_ids);
236
237static struct platform_driver rzg2l_thermal_driver = {
238 .driver = {
239 .name = "rzg2l_thermal",
240 .of_match_table = rzg2l_thermal_dt_ids,
241 },
242 .probe = rzg2l_thermal_probe,
243 .remove_new = rzg2l_thermal_remove,
244};
245module_platform_driver(rzg2l_thermal_driver);
246
247MODULE_DESCRIPTION("Renesas RZ/G2L TSU Thermal Sensor Driver");
248MODULE_AUTHOR("Biju Das <biju.das.jz@bp.renesas.com>");
249MODULE_LICENSE("GPL v2");
250

source code of linux/drivers/thermal/rzg2l_thermal.c