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
57 struct 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
rzg2l_thermal_read(struct rzg2l_thermal_priv * priv,u32 reg)65 static inline u32 rzg2l_thermal_read(struct rzg2l_thermal_priv *priv, u32 reg)
66 {
67 return ioread32(priv->base + reg);
68 }
69
rzg2l_thermal_write(struct rzg2l_thermal_priv * priv,u32 reg,u32 data)70 static inline void rzg2l_thermal_write(struct rzg2l_thermal_priv *priv, u32 reg,
71 u32 data)
72 {
73 iowrite32(data, priv->base + reg);
74 }
75
rzg2l_thermal_get_temp(struct thermal_zone_device * tz,int * temp)76 static int rzg2l_thermal_get_temp(struct thermal_zone_device *tz, int *temp)
77 {
78 struct rzg2l_thermal_priv *priv = thermal_zone_device_priv(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(20, 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
117 static const struct thermal_zone_device_ops rzg2l_tz_of_ops = {
118 .get_temp = rzg2l_thermal_get_temp,
119 };
120
rzg2l_thermal_init(struct rzg2l_thermal_priv * priv)121 static 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, 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(60, 80);
134
135 reg_val = rzg2l_thermal_read(priv, TSU_ST);
136 reg_val |= TSU_ST_START;
137 rzg2l_thermal_write(priv, TSU_ST, 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
rzg2l_thermal_reset_assert_pm_disable_put(struct platform_device * pdev)144 static void rzg2l_thermal_reset_assert_pm_disable_put(struct platform_device *pdev)
145 {
146 struct rzg2l_thermal_priv *priv = dev_get_drvdata(&pdev->dev);
147
148 pm_runtime_put(&pdev->dev);
149 pm_runtime_disable(&pdev->dev);
150 reset_control_assert(priv->rstc);
151 }
152
rzg2l_thermal_remove(struct platform_device * pdev)153 static int rzg2l_thermal_remove(struct platform_device *pdev)
154 {
155 struct rzg2l_thermal_priv *priv = dev_get_drvdata(&pdev->dev);
156
157 thermal_remove_hwmon_sysfs(priv->zone);
158 rzg2l_thermal_reset_assert_pm_disable_put(pdev);
159
160 return 0;
161 }
162
rzg2l_thermal_probe(struct platform_device * pdev)163 static int rzg2l_thermal_probe(struct platform_device *pdev)
164 {
165 struct thermal_zone_device *zone;
166 struct rzg2l_thermal_priv *priv;
167 struct device *dev = &pdev->dev;
168 int ret;
169
170 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
171 if (!priv)
172 return -ENOMEM;
173
174 priv->base = devm_platform_ioremap_resource(pdev, 0);
175 if (IS_ERR(priv->base))
176 return PTR_ERR(priv->base);
177
178 priv->dev = dev;
179 priv->rstc = devm_reset_control_get_exclusive(dev, NULL);
180 if (IS_ERR(priv->rstc))
181 return dev_err_probe(dev, PTR_ERR(priv->rstc),
182 "failed to get cpg reset");
183
184 ret = reset_control_deassert(priv->rstc);
185 if (ret)
186 return dev_err_probe(dev, ret, "failed to deassert");
187
188 pm_runtime_enable(dev);
189 pm_runtime_get_sync(dev);
190
191 priv->calib0 = rzg2l_thermal_read(priv, OTPTSUTRIM_REG(0));
192 if (priv->calib0 & OTPTSUTRIM_EN_MASK)
193 priv->calib0 &= OTPTSUTRIM_MASK;
194 else
195 priv->calib0 = SW_CALIB0_VAL;
196
197 priv->calib1 = rzg2l_thermal_read(priv, OTPTSUTRIM_REG(1));
198 if (priv->calib1 & OTPTSUTRIM_EN_MASK)
199 priv->calib1 &= OTPTSUTRIM_MASK;
200 else
201 priv->calib1 = SW_CALIB1_VAL;
202
203 platform_set_drvdata(pdev, priv);
204 ret = rzg2l_thermal_init(priv);
205 if (ret) {
206 dev_err(dev, "Failed to start TSU");
207 goto err;
208 }
209
210 zone = devm_thermal_of_zone_register(dev, 0, priv,
211 &rzg2l_tz_of_ops);
212 if (IS_ERR(zone)) {
213 dev_err(dev, "Can't register thermal zone");
214 ret = PTR_ERR(zone);
215 goto err;
216 }
217
218 priv->zone = zone;
219 ret = thermal_add_hwmon_sysfs(priv->zone);
220 if (ret)
221 goto err;
222
223 dev_dbg(dev, "TSU probed with %s calibration values",
224 rzg2l_thermal_read(priv, OTPTSUTRIM_REG(0)) ? "hw" : "sw");
225
226 return 0;
227
228 err:
229 rzg2l_thermal_reset_assert_pm_disable_put(pdev);
230 return ret;
231 }
232
233 static const struct of_device_id rzg2l_thermal_dt_ids[] = {
234 { .compatible = "renesas,rzg2l-tsu", },
235 { /* sentinel */ }
236 };
237 MODULE_DEVICE_TABLE(of, rzg2l_thermal_dt_ids);
238
239 static struct platform_driver rzg2l_thermal_driver = {
240 .driver = {
241 .name = "rzg2l_thermal",
242 .of_match_table = rzg2l_thermal_dt_ids,
243 },
244 .probe = rzg2l_thermal_probe,
245 .remove = rzg2l_thermal_remove,
246 };
247 module_platform_driver(rzg2l_thermal_driver);
248
249 MODULE_DESCRIPTION("Renesas RZ/G2L TSU Thermal Sensor Driver");
250 MODULE_AUTHOR("Biju Das <biju.das.jz@bp.renesas.com>");
251 MODULE_LICENSE("GPL v2");
252