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1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* | |
3 | * TI Bandgap temperature sensor driver for K3 SoC Family | |
4 | * | |
5 | * Copyright (C) 2020 Texas Instruments Incorporated - http://www.ti.com/ | |
6 | */ | |
7 | ||
8 | #include <linux/err.h> | |
9 | #include <linux/init.h> | |
10 | #include <linux/io.h> | |
11 | #include <linux/kernel.h> | |
12 | #include <linux/module.h> | |
13 | #include <linux/of.h> | |
14 | #include <linux/of_platform.h> | |
15 | #include <linux/pm_runtime.h> | |
16 | #include <linux/thermal.h> | |
17 | #include <linux/types.h> | |
18 | ||
19 | #define K3_VTM_DEVINFO_PWR0_OFFSET 0x4 | |
20 | #define K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK 0xf0 | |
21 | #define K3_VTM_TMPSENS0_CTRL_OFFSET 0x80 | |
22 | #define K3_VTM_REGS_PER_TS 0x10 | |
23 | #define K3_VTM_TS_STAT_DTEMP_MASK 0x3ff | |
24 | #define K3_VTM_TMPSENS_CTRL_CBIASSEL BIT(0) | |
25 | #define K3_VTM_TMPSENS_CTRL_SOC BIT(5) | |
26 | #define K3_VTM_TMPSENS_CTRL_CLRZ BIT(6) | |
27 | #define K3_VTM_TMPSENS_CTRL_CLKON_REQ BIT(7) | |
28 | ||
29 | #define K3_VTM_ADC_BEGIN_VAL 540 | |
30 | #define K3_VTM_ADC_END_VAL 944 | |
31 | ||
32 | static const int k3_adc_to_temp[] = { | |
33 | -40000, -40000, -40000, -40000, -39800, -39400, -39000, -38600, -38200, | |
34 | -37800, -37400, -37000, -36600, -36200, -35800, -35300, -34700, -34200, | |
35 | -33800, -33400, -33000, -32600, -32200, -31800, -31400, -31000, -30600, | |
36 | -30200, -29800, -29400, -29000, -28600, -28200, -27700, -27100, -26600, | |
37 | -26200, -25800, -25400, -25000, -24600, -24200, -23800, -23400, -23000, | |
38 | -22600, -22200, -21800, -21400, -21000, -20500, -19900, -19400, -19000, | |
39 | -18600, -18200, -17800, -17400, -17000, -16600, -16200, -15800, -15400, | |
40 | -15000, -14600, -14200, -13800, -13400, -13000, -12500, -11900, -11400, | |
41 | -11000, -10600, -10200, -9800, -9400, -9000, -8600, -8200, -7800, -7400, | |
42 | -7000, -6600, -6200, -5800, -5400, -5000, -4500, -3900, -3400, -3000, | |
43 | -2600, -2200, -1800, -1400, -1000, -600, -200, 200, 600, 1000, 1400, | |
44 | 1800, 2200, 2600, 3000, 3400, 3900, 4500, 5000, 5400, 5800, 6200, 6600, | |
45 | 7000, 7400, 7800, 8200, 8600, 9000, 9400, 9800, 10200, 10600, 11000, | |
46 | 11400, 11800, 12200, 12700, 13300, 13800, 14200, 14600, 15000, 15400, | |
47 | 15800, 16200, 16600, 17000, 17400, 17800, 18200, 18600, 19000, 19400, | |
48 | 19800, 20200, 20600, 21000, 21400, 21900, 22500, 23000, 23400, 23800, | |
49 | 24200, 24600, 25000, 25400, 25800, 26200, 26600, 27000, 27400, 27800, | |
50 | 28200, 28600, 29000, 29400, 29800, 30200, 30600, 31000, 31400, 31900, | |
51 | 32500, 33000, 33400, 33800, 34200, 34600, 35000, 35400, 35800, 36200, | |
52 | 36600, 37000, 37400, 37800, 38200, 38600, 39000, 39400, 39800, 40200, | |
53 | 40600, 41000, 41400, 41800, 42200, 42600, 43100, 43700, 44200, 44600, | |
54 | 45000, 45400, 45800, 46200, 46600, 47000, 47400, 47800, 48200, 48600, | |
55 | 49000, 49400, 49800, 50200, 50600, 51000, 51400, 51800, 52200, 52600, | |
56 | 53000, 53400, 53800, 54200, 54600, 55000, 55400, 55900, 56500, 57000, | |
57 | 57400, 57800, 58200, 58600, 59000, 59400, 59800, 60200, 60600, 61000, | |
58 | 61400, 61800, 62200, 62600, 63000, 63400, 63800, 64200, 64600, 65000, | |
59 | 65400, 65800, 66200, 66600, 67000, 67400, 67800, 68200, 68600, 69000, | |
60 | 69400, 69800, 70200, 70600, 71000, 71500, 72100, 72600, 73000, 73400, | |
61 | 73800, 74200, 74600, 75000, 75400, 75800, 76200, 76600, 77000, 77400, | |
62 | 77800, 78200, 78600, 79000, 79400, 79800, 80200, 80600, 81000, 81400, | |
63 | 81800, 82200, 82600, 83000, 83400, 83800, 84200, 84600, 85000, 85400, | |
64 | 85800, 86200, 86600, 87000, 87400, 87800, 88200, 88600, 89000, 89400, | |
65 | 89800, 90200, 90600, 91000, 91400, 91800, 92200, 92600, 93000, 93400, | |
66 | 93800, 94200, 94600, 95000, 95400, 95800, 96200, 96600, 97000, 97500, | |
67 | 98100, 98600, 99000, 99400, 99800, 100200, 100600, 101000, 101400, | |
68 | 101800, 102200, 102600, 103000, 103400, 103800, 104200, 104600, 105000, | |
69 | 105400, 105800, 106200, 106600, 107000, 107400, 107800, 108200, 108600, | |
70 | 109000, 109400, 109800, 110200, 110600, 111000, 111400, 111800, 112200, | |
71 | 112600, 113000, 113400, 113800, 114200, 114600, 115000, 115400, 115800, | |
72 | 116200, 116600, 117000, 117400, 117800, 118200, 118600, 119000, 119400, | |
73 | 119800, 120200, 120600, 121000, 121400, 121800, 122200, 122600, 123000, | |
74 | 123400, 123800, 124200, 124600, 124900, 125000, | |
75 | }; | |
76 | ||
77 | struct k3_bandgap { | |
78 | void __iomem *base; | |
79 | const struct k3_bandgap_data *conf; | |
80 | }; | |
81 | ||
82 | /* common data structures */ | |
83 | struct k3_thermal_data { | |
84 | struct thermal_zone_device *tzd; | |
85 | struct k3_bandgap *bgp; | |
86 | int sensor_id; | |
87 | u32 ctrl_offset; | |
88 | u32 stat_offset; | |
89 | }; | |
90 | ||
91 | static unsigned int vtm_get_best_value(unsigned int s0, unsigned int s1, | |
92 | unsigned int s2) | |
93 | { | |
94 | int d01 = abs(s0 - s1); | |
95 | int d02 = abs(s0 - s2); | |
96 | int d12 = abs(s1 - s2); | |
97 | ||
98 | if (d01 <= d02 && d01 <= d12) | |
99 | return (s0 + s1) / 2; | |
100 | ||
101 | if (d02 <= d01 && d02 <= d12) | |
102 | return (s0 + s2) / 2; | |
103 | ||
104 | return (s1 + s2) / 2; | |
105 | } | |
106 | ||
107 | static int k3_bgp_read_temp(struct k3_thermal_data *devdata, | |
108 | int *temp) | |
109 | { | |
110 | struct k3_bandgap *bgp; | |
111 | unsigned int dtemp, s0, s1, s2; | |
112 | ||
113 | bgp = devdata->bgp; | |
114 | ||
115 | /* | |
116 | * Errata is applicable for am654 pg 1.0 silicon. There | |
117 | * is a variation of the order for 8-10 degree centigrade. | |
118 | * Work around that by getting the average of two closest | |
119 | * readings out of three readings everytime we want to | |
120 | * report temperatures. | |
121 | * | |
122 | * Errata workaround. | |
123 | */ | |
124 | s0 = readl(bgp->base + devdata->stat_offset) & | |
125 | K3_VTM_TS_STAT_DTEMP_MASK; | |
126 | s1 = readl(bgp->base + devdata->stat_offset) & | |
127 | K3_VTM_TS_STAT_DTEMP_MASK; | |
128 | s2 = readl(bgp->base + devdata->stat_offset) & | |
129 | K3_VTM_TS_STAT_DTEMP_MASK; | |
130 | dtemp = vtm_get_best_value(s0, s1, s2); | |
131 | ||
132 | if (dtemp < K3_VTM_ADC_BEGIN_VAL || dtemp > K3_VTM_ADC_END_VAL) | |
133 | return -EINVAL; | |
134 | ||
135 | *temp = k3_adc_to_temp[dtemp - K3_VTM_ADC_BEGIN_VAL]; | |
136 | ||
137 | return 0; | |
138 | } | |
139 | ||
140 | static int k3_thermal_get_temp(void *devdata, int *temp) | |
141 | { | |
142 | struct k3_thermal_data *data = devdata; | |
143 | int ret = 0; | |
144 | ||
145 | ret = k3_bgp_read_temp(data, temp); | |
146 | if (ret) | |
147 | return ret; | |
148 | ||
149 | return ret; | |
150 | } | |
151 | ||
152 | static const struct thermal_zone_of_device_ops k3_of_thermal_ops = { | |
153 | .get_temp = k3_thermal_get_temp, | |
154 | }; | |
155 | ||
156 | static const struct of_device_id of_k3_bandgap_match[]; | |
157 | ||
158 | static int k3_bandgap_probe(struct platform_device *pdev) | |
159 | { | |
160 | int ret = 0, cnt, val, id; | |
161 | struct resource *res; | |
162 | struct device *dev = &pdev->dev; | |
163 | struct k3_bandgap *bgp; | |
164 | struct k3_thermal_data *data; | |
165 | ||
166 | if (ARRAY_SIZE(k3_adc_to_temp) != (K3_VTM_ADC_END_VAL + 1 - | |
167 | K3_VTM_ADC_BEGIN_VAL)) | |
168 | return -EINVAL; | |
169 | ||
170 | bgp = devm_kzalloc(&pdev->dev, sizeof(*bgp), GFP_KERNEL); | |
171 | if (!bgp) | |
172 | return -ENOMEM; | |
173 | ||
174 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
175 | bgp->base = devm_ioremap_resource(dev, res); | |
176 | if (IS_ERR(bgp->base)) | |
177 | return PTR_ERR(bgp->base); | |
178 | ||
179 | pm_runtime_enable(dev); | |
180 | ret = pm_runtime_get_sync(dev); | |
181 | if (ret < 0) { | |
182 | pm_runtime_put_noidle(dev); | |
183 | pm_runtime_disable(dev); | |
184 | return ret; | |
185 | } | |
186 | ||
187 | /* Get the sensor count in the VTM */ | |
188 | val = readl(bgp->base + K3_VTM_DEVINFO_PWR0_OFFSET); | |
189 | cnt = val & K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK; | |
190 | cnt >>= __ffs(K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK); | |
191 | ||
192 | data = devm_kcalloc(dev, cnt, sizeof(*data), GFP_KERNEL); | |
193 | if (!data) { | |
194 | ret = -ENOMEM; | |
195 | goto err_alloc; | |
196 | } | |
197 | ||
198 | /* Register the thermal sensors */ | |
199 | for (id = 0; id < cnt; id++) { | |
200 | data[id].sensor_id = id; | |
201 | data[id].bgp = bgp; | |
202 | data[id].ctrl_offset = K3_VTM_TMPSENS0_CTRL_OFFSET + | |
203 | id * K3_VTM_REGS_PER_TS; | |
204 | data[id].stat_offset = data[id].ctrl_offset + 0x8; | |
205 | ||
206 | val = readl(data[id].bgp->base + data[id].ctrl_offset); | |
207 | val |= (K3_VTM_TMPSENS_CTRL_SOC | | |
208 | K3_VTM_TMPSENS_CTRL_CLRZ | | |
209 | K3_VTM_TMPSENS_CTRL_CLKON_REQ); | |
210 | val &= ~K3_VTM_TMPSENS_CTRL_CBIASSEL; | |
211 | writel(val, data[id].bgp->base + data[id].ctrl_offset); | |
212 | ||
213 | data[id].tzd = | |
214 | devm_thermal_zone_of_sensor_register(dev, id, | |
215 | &data[id], | |
216 | &k3_of_thermal_ops); | |
217 | if (IS_ERR(data[id].tzd)) { | |
218 | dev_err(dev, "thermal zone device is NULL\n"); | |
219 | ret = PTR_ERR(data[id].tzd); | |
220 | goto err_alloc; | |
221 | } | |
222 | } | |
223 | ||
224 | platform_set_drvdata(pdev, bgp); | |
225 | ||
226 | return 0; | |
227 | ||
228 | err_alloc: | |
229 | pm_runtime_put_sync(dev); | |
230 | pm_runtime_disable(dev); | |
231 | ||
232 | return ret; | |
233 | } | |
234 | ||
235 | static int k3_bandgap_remove(struct platform_device *pdev) | |
236 | { | |
237 | pm_runtime_put_sync(&pdev->dev); | |
238 | pm_runtime_disable(&pdev->dev); | |
239 | ||
240 | return 0; | |
241 | } | |
242 | ||
243 | static const struct of_device_id of_k3_bandgap_match[] = { | |
244 | { | |
245 | .compatible = "ti,am654-vtm", | |
246 | }, | |
247 | { /* sentinel */ }, | |
248 | }; | |
249 | MODULE_DEVICE_TABLE(of, of_k3_bandgap_match); | |
250 | ||
251 | static struct platform_driver k3_bandgap_sensor_driver = { | |
252 | .probe = k3_bandgap_probe, | |
253 | .remove = k3_bandgap_remove, | |
254 | .driver = { | |
255 | .name = "k3-soc-thermal", | |
256 | .of_match_table = of_k3_bandgap_match, | |
257 | }, | |
258 | }; | |
259 | ||
260 | module_platform_driver(k3_bandgap_sensor_driver); | |
261 | ||
262 | MODULE_DESCRIPTION("K3 bandgap temperature sensor driver"); | |
263 | MODULE_LICENSE("GPL v2"); | |
264 | MODULE_AUTHOR("J Keerthy <j-keerthy@ti.com>"); |