Commit | Line | Data |
---|---|---|
7f2958e8 ERB |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* | |
3 | * Copyright (C) 2021 Emil Renner Berthing <kernel@esmil.dk> | |
4 | * Copyright (C) 2021 Samin Guo <samin.guo@starfivetech.com> | |
5 | */ | |
6 | ||
7 | #include <linux/bits.h> | |
8 | #include <linux/clk.h> | |
9 | #include <linux/delay.h> | |
10 | #include <linux/hwmon.h> | |
11 | #include <linux/io.h> | |
12 | #include <linux/module.h> | |
13 | #include <linux/mutex.h> | |
14 | #include <linux/of.h> | |
15 | #include <linux/platform_device.h> | |
16 | #include <linux/reset.h> | |
17 | ||
18 | /* | |
19 | * TempSensor reset. The RSTN can be de-asserted once the analog core has | |
20 | * powered up. Trst(min 100ns) | |
21 | * 0:reset 1:de-assert | |
22 | */ | |
23 | #define SFCTEMP_RSTN BIT(0) | |
24 | ||
25 | /* | |
26 | * TempSensor analog core power down. The analog core will be powered up | |
27 | * Tpu(min 50us) after PD is de-asserted. RSTN should be held low until the | |
28 | * analog core is powered up. | |
29 | * 0:power up 1:power down | |
30 | */ | |
31 | #define SFCTEMP_PD BIT(1) | |
32 | ||
33 | /* | |
34 | * TempSensor start conversion enable. | |
35 | * 0:disable 1:enable | |
36 | */ | |
37 | #define SFCTEMP_RUN BIT(2) | |
38 | ||
39 | /* | |
40 | * TempSensor conversion value output. | |
41 | * Temp(C)=DOUT*Y/4094 - K | |
42 | */ | |
43 | #define SFCTEMP_DOUT_POS 16 | |
44 | #define SFCTEMP_DOUT_MSK GENMASK(27, 16) | |
45 | ||
46 | /* DOUT to Celcius conversion constants */ | |
47 | #define SFCTEMP_Y1000 237500L | |
48 | #define SFCTEMP_Z 4094L | |
49 | #define SFCTEMP_K1000 81100L | |
50 | ||
51 | struct sfctemp { | |
52 | /* serialize access to hardware register and enabled below */ | |
53 | struct mutex lock; | |
54 | void __iomem *regs; | |
55 | struct clk *clk_sense; | |
56 | struct clk *clk_bus; | |
57 | struct reset_control *rst_sense; | |
58 | struct reset_control *rst_bus; | |
59 | bool enabled; | |
60 | }; | |
61 | ||
62 | static void sfctemp_power_up(struct sfctemp *sfctemp) | |
63 | { | |
64 | /* make sure we're powered down first */ | |
65 | writel(SFCTEMP_PD, sfctemp->regs); | |
66 | udelay(1); | |
67 | ||
68 | writel(0, sfctemp->regs); | |
69 | /* wait t_pu(50us) + t_rst(100ns) */ | |
70 | usleep_range(60, 200); | |
71 | ||
72 | /* de-assert reset */ | |
73 | writel(SFCTEMP_RSTN, sfctemp->regs); | |
74 | udelay(1); /* wait t_su(500ps) */ | |
75 | } | |
76 | ||
77 | static void sfctemp_power_down(struct sfctemp *sfctemp) | |
78 | { | |
79 | writel(SFCTEMP_PD, sfctemp->regs); | |
80 | } | |
81 | ||
82 | static void sfctemp_run(struct sfctemp *sfctemp) | |
83 | { | |
84 | writel(SFCTEMP_RSTN | SFCTEMP_RUN, sfctemp->regs); | |
85 | udelay(1); | |
86 | } | |
87 | ||
88 | static void sfctemp_stop(struct sfctemp *sfctemp) | |
89 | { | |
90 | writel(SFCTEMP_RSTN, sfctemp->regs); | |
91 | } | |
92 | ||
93 | static int sfctemp_enable(struct sfctemp *sfctemp) | |
94 | { | |
95 | int ret = 0; | |
96 | ||
97 | mutex_lock(&sfctemp->lock); | |
98 | if (sfctemp->enabled) | |
99 | goto done; | |
100 | ||
101 | ret = clk_prepare_enable(sfctemp->clk_bus); | |
102 | if (ret) | |
103 | goto err; | |
104 | ret = reset_control_deassert(sfctemp->rst_bus); | |
105 | if (ret) | |
106 | goto err_disable_bus; | |
107 | ||
108 | ret = clk_prepare_enable(sfctemp->clk_sense); | |
109 | if (ret) | |
110 | goto err_assert_bus; | |
111 | ret = reset_control_deassert(sfctemp->rst_sense); | |
112 | if (ret) | |
113 | goto err_disable_sense; | |
114 | ||
115 | sfctemp_power_up(sfctemp); | |
116 | sfctemp_run(sfctemp); | |
117 | sfctemp->enabled = true; | |
118 | done: | |
119 | mutex_unlock(&sfctemp->lock); | |
120 | return ret; | |
121 | ||
122 | err_disable_sense: | |
123 | clk_disable_unprepare(sfctemp->clk_sense); | |
124 | err_assert_bus: | |
125 | reset_control_assert(sfctemp->rst_bus); | |
126 | err_disable_bus: | |
127 | clk_disable_unprepare(sfctemp->clk_bus); | |
128 | err: | |
129 | mutex_unlock(&sfctemp->lock); | |
130 | return ret; | |
131 | } | |
132 | ||
133 | static int sfctemp_disable(struct sfctemp *sfctemp) | |
134 | { | |
135 | mutex_lock(&sfctemp->lock); | |
136 | if (!sfctemp->enabled) | |
137 | goto done; | |
138 | ||
139 | sfctemp_stop(sfctemp); | |
140 | sfctemp_power_down(sfctemp); | |
141 | reset_control_assert(sfctemp->rst_sense); | |
142 | clk_disable_unprepare(sfctemp->clk_sense); | |
143 | reset_control_assert(sfctemp->rst_bus); | |
144 | clk_disable_unprepare(sfctemp->clk_bus); | |
145 | sfctemp->enabled = false; | |
146 | done: | |
147 | mutex_unlock(&sfctemp->lock); | |
148 | return 0; | |
149 | } | |
150 | ||
151 | static void sfctemp_disable_action(void *data) | |
152 | { | |
153 | sfctemp_disable(data); | |
154 | } | |
155 | ||
156 | static int sfctemp_convert(struct sfctemp *sfctemp, long *val) | |
157 | { | |
158 | int ret; | |
159 | ||
160 | mutex_lock(&sfctemp->lock); | |
161 | if (!sfctemp->enabled) { | |
162 | ret = -ENODATA; | |
163 | goto out; | |
164 | } | |
165 | ||
166 | /* calculate temperature in milli Celcius */ | |
167 | *val = (long)((readl(sfctemp->regs) & SFCTEMP_DOUT_MSK) >> SFCTEMP_DOUT_POS) | |
168 | * SFCTEMP_Y1000 / SFCTEMP_Z - SFCTEMP_K1000; | |
169 | ||
170 | ret = 0; | |
171 | out: | |
172 | mutex_unlock(&sfctemp->lock); | |
173 | return ret; | |
174 | } | |
175 | ||
176 | static umode_t sfctemp_is_visible(const void *data, enum hwmon_sensor_types type, | |
177 | u32 attr, int channel) | |
178 | { | |
179 | switch (type) { | |
180 | case hwmon_temp: | |
181 | switch (attr) { | |
182 | case hwmon_temp_enable: | |
183 | return 0644; | |
184 | case hwmon_temp_input: | |
185 | return 0444; | |
186 | default: | |
187 | return 0; | |
188 | } | |
189 | default: | |
190 | return 0; | |
191 | } | |
192 | } | |
193 | ||
194 | static int sfctemp_read(struct device *dev, enum hwmon_sensor_types type, | |
195 | u32 attr, int channel, long *val) | |
196 | { | |
197 | struct sfctemp *sfctemp = dev_get_drvdata(dev); | |
198 | ||
199 | switch (type) { | |
200 | case hwmon_temp: | |
201 | switch (attr) { | |
202 | case hwmon_temp_enable: | |
203 | *val = sfctemp->enabled; | |
204 | return 0; | |
205 | case hwmon_temp_input: | |
206 | return sfctemp_convert(sfctemp, val); | |
207 | default: | |
208 | return -EINVAL; | |
209 | } | |
210 | default: | |
211 | return -EINVAL; | |
212 | } | |
213 | } | |
214 | ||
215 | static int sfctemp_write(struct device *dev, enum hwmon_sensor_types type, | |
216 | u32 attr, int channel, long val) | |
217 | { | |
218 | struct sfctemp *sfctemp = dev_get_drvdata(dev); | |
219 | ||
220 | switch (type) { | |
221 | case hwmon_temp: | |
222 | switch (attr) { | |
223 | case hwmon_temp_enable: | |
224 | if (val == 0) | |
225 | return sfctemp_disable(sfctemp); | |
226 | if (val == 1) | |
227 | return sfctemp_enable(sfctemp); | |
228 | return -EINVAL; | |
229 | default: | |
230 | return -EINVAL; | |
231 | } | |
232 | default: | |
233 | return -EINVAL; | |
234 | } | |
235 | } | |
236 | ||
237 | static const struct hwmon_channel_info *sfctemp_info[] = { | |
238 | HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ), | |
239 | HWMON_CHANNEL_INFO(temp, HWMON_T_ENABLE | HWMON_T_INPUT), | |
240 | NULL | |
241 | }; | |
242 | ||
243 | static const struct hwmon_ops sfctemp_hwmon_ops = { | |
244 | .is_visible = sfctemp_is_visible, | |
245 | .read = sfctemp_read, | |
246 | .write = sfctemp_write, | |
247 | }; | |
248 | ||
249 | static const struct hwmon_chip_info sfctemp_chip_info = { | |
250 | .ops = &sfctemp_hwmon_ops, | |
251 | .info = sfctemp_info, | |
252 | }; | |
253 | ||
254 | static int sfctemp_probe(struct platform_device *pdev) | |
255 | { | |
256 | struct device *dev = &pdev->dev; | |
257 | struct device *hwmon_dev; | |
258 | struct sfctemp *sfctemp; | |
259 | int ret; | |
260 | ||
261 | sfctemp = devm_kzalloc(dev, sizeof(*sfctemp), GFP_KERNEL); | |
262 | if (!sfctemp) | |
263 | return -ENOMEM; | |
264 | ||
265 | dev_set_drvdata(dev, sfctemp); | |
266 | mutex_init(&sfctemp->lock); | |
267 | ||
268 | sfctemp->regs = devm_platform_ioremap_resource(pdev, 0); | |
269 | if (IS_ERR(sfctemp->regs)) | |
270 | return PTR_ERR(sfctemp->regs); | |
271 | ||
272 | sfctemp->clk_sense = devm_clk_get(dev, "sense"); | |
273 | if (IS_ERR(sfctemp->clk_sense)) | |
274 | return dev_err_probe(dev, PTR_ERR(sfctemp->clk_sense), | |
275 | "error getting sense clock\n"); | |
276 | ||
277 | sfctemp->clk_bus = devm_clk_get(dev, "bus"); | |
278 | if (IS_ERR(sfctemp->clk_bus)) | |
279 | return dev_err_probe(dev, PTR_ERR(sfctemp->clk_bus), | |
280 | "error getting bus clock\n"); | |
281 | ||
282 | sfctemp->rst_sense = devm_reset_control_get_exclusive(dev, "sense"); | |
283 | if (IS_ERR(sfctemp->rst_sense)) | |
284 | return dev_err_probe(dev, PTR_ERR(sfctemp->rst_sense), | |
285 | "error getting sense reset\n"); | |
286 | ||
287 | sfctemp->rst_bus = devm_reset_control_get_exclusive(dev, "bus"); | |
288 | if (IS_ERR(sfctemp->rst_bus)) | |
289 | return dev_err_probe(dev, PTR_ERR(sfctemp->rst_bus), | |
290 | "error getting busreset\n"); | |
291 | ||
292 | ret = reset_control_assert(sfctemp->rst_sense); | |
293 | if (ret) | |
294 | return dev_err_probe(dev, ret, "error asserting sense reset\n"); | |
295 | ||
296 | ret = reset_control_assert(sfctemp->rst_bus); | |
297 | if (ret) | |
298 | return dev_err_probe(dev, ret, "error asserting bus reset\n"); | |
299 | ||
300 | ret = devm_add_action(dev, sfctemp_disable_action, sfctemp); | |
301 | if (ret) | |
302 | return ret; | |
303 | ||
304 | ret = sfctemp_enable(sfctemp); | |
305 | if (ret) | |
fb23f230 | 306 | return dev_err_probe(dev, ret, "error enabling temperature sensor\n"); |
7f2958e8 ERB |
307 | |
308 | hwmon_dev = devm_hwmon_device_register_with_info(dev, "sfctemp", sfctemp, | |
309 | &sfctemp_chip_info, NULL); | |
310 | return PTR_ERR_OR_ZERO(hwmon_dev); | |
311 | } | |
312 | ||
313 | static const struct of_device_id sfctemp_of_match[] = { | |
314 | { .compatible = "starfive,jh7100-temp" }, | |
315 | { .compatible = "starfive,jh7110-temp" }, | |
316 | { /* sentinel */ } | |
317 | }; | |
318 | MODULE_DEVICE_TABLE(of, sfctemp_of_match); | |
319 | ||
320 | static struct platform_driver sfctemp_driver = { | |
321 | .probe = sfctemp_probe, | |
322 | .driver = { | |
323 | .name = "sfctemp", | |
324 | .of_match_table = sfctemp_of_match, | |
325 | }, | |
326 | }; | |
327 | module_platform_driver(sfctemp_driver); | |
328 | ||
329 | MODULE_AUTHOR("Emil Renner Berthing"); | |
330 | MODULE_DESCRIPTION("StarFive JH71x0 temperature sensor driver"); | |
331 | MODULE_LICENSE("GPL"); |