1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2021 Emil Renner Berthing <kernel@esmil.dk>
4 * Copyright (C) 2021 Samin Guo <samin.guo@starfivetech.com>
7 #include <linux/bits.h>
9 #include <linux/delay.h>
10 #include <linux/hwmon.h>
12 #include <linux/module.h>
13 #include <linux/mutex.h>
15 #include <linux/platform_device.h>
16 #include <linux/reset.h>
19 * TempSensor reset. The RSTN can be de-asserted once the analog core has
20 * powered up. Trst(min 100ns)
23 #define SFCTEMP_RSTN BIT(0)
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
31 #define SFCTEMP_PD BIT(1)
34 * TempSensor start conversion enable.
37 #define SFCTEMP_RUN BIT(2)
40 * TempSensor conversion value output.
41 * Temp(C)=DOUT*Y/4094 - K
43 #define SFCTEMP_DOUT_POS 16
44 #define SFCTEMP_DOUT_MSK GENMASK(27, 16)
46 /* DOUT to Celcius conversion constants */
47 #define SFCTEMP_Y1000 237500L
48 #define SFCTEMP_Z 4094L
49 #define SFCTEMP_K1000 81100L
52 /* serialize access to hardware register and enabled below */
55 struct clk *clk_sense;
57 struct reset_control *rst_sense;
58 struct reset_control *rst_bus;
62 static void sfctemp_power_up(struct sfctemp *sfctemp)
64 /* make sure we're powered down first */
65 writel(SFCTEMP_PD, sfctemp->regs);
68 writel(0, sfctemp->regs);
69 /* wait t_pu(50us) + t_rst(100ns) */
70 usleep_range(60, 200);
73 writel(SFCTEMP_RSTN, sfctemp->regs);
74 udelay(1); /* wait t_su(500ps) */
77 static void sfctemp_power_down(struct sfctemp *sfctemp)
79 writel(SFCTEMP_PD, sfctemp->regs);
82 static void sfctemp_run(struct sfctemp *sfctemp)
84 writel(SFCTEMP_RSTN | SFCTEMP_RUN, sfctemp->regs);
88 static void sfctemp_stop(struct sfctemp *sfctemp)
90 writel(SFCTEMP_RSTN, sfctemp->regs);
93 static int sfctemp_enable(struct sfctemp *sfctemp)
97 mutex_lock(&sfctemp->lock);
101 ret = clk_prepare_enable(sfctemp->clk_bus);
104 ret = reset_control_deassert(sfctemp->rst_bus);
106 goto err_disable_bus;
108 ret = clk_prepare_enable(sfctemp->clk_sense);
111 ret = reset_control_deassert(sfctemp->rst_sense);
113 goto err_disable_sense;
115 sfctemp_power_up(sfctemp);
116 sfctemp_run(sfctemp);
117 sfctemp->enabled = true;
119 mutex_unlock(&sfctemp->lock);
123 clk_disable_unprepare(sfctemp->clk_sense);
125 reset_control_assert(sfctemp->rst_bus);
127 clk_disable_unprepare(sfctemp->clk_bus);
129 mutex_unlock(&sfctemp->lock);
133 static int sfctemp_disable(struct sfctemp *sfctemp)
135 mutex_lock(&sfctemp->lock);
136 if (!sfctemp->enabled)
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;
147 mutex_unlock(&sfctemp->lock);
151 static void sfctemp_disable_action(void *data)
153 sfctemp_disable(data);
156 static int sfctemp_convert(struct sfctemp *sfctemp, long *val)
160 mutex_lock(&sfctemp->lock);
161 if (!sfctemp->enabled) {
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;
172 mutex_unlock(&sfctemp->lock);
176 static umode_t sfctemp_is_visible(const void *data, enum hwmon_sensor_types type,
177 u32 attr, int channel)
182 case hwmon_temp_enable:
184 case hwmon_temp_input:
194 static int sfctemp_read(struct device *dev, enum hwmon_sensor_types type,
195 u32 attr, int channel, long *val)
197 struct sfctemp *sfctemp = dev_get_drvdata(dev);
202 case hwmon_temp_enable:
203 *val = sfctemp->enabled;
205 case hwmon_temp_input:
206 return sfctemp_convert(sfctemp, val);
215 static int sfctemp_write(struct device *dev, enum hwmon_sensor_types type,
216 u32 attr, int channel, long val)
218 struct sfctemp *sfctemp = dev_get_drvdata(dev);
223 case hwmon_temp_enable:
225 return sfctemp_disable(sfctemp);
227 return sfctemp_enable(sfctemp);
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),
243 static const struct hwmon_ops sfctemp_hwmon_ops = {
244 .is_visible = sfctemp_is_visible,
245 .read = sfctemp_read,
246 .write = sfctemp_write,
249 static const struct hwmon_chip_info sfctemp_chip_info = {
250 .ops = &sfctemp_hwmon_ops,
251 .info = sfctemp_info,
254 static int sfctemp_probe(struct platform_device *pdev)
256 struct device *dev = &pdev->dev;
257 struct device *hwmon_dev;
258 struct sfctemp *sfctemp;
261 sfctemp = devm_kzalloc(dev, sizeof(*sfctemp), GFP_KERNEL);
265 dev_set_drvdata(dev, sfctemp);
266 mutex_init(&sfctemp->lock);
268 sfctemp->regs = devm_platform_ioremap_resource(pdev, 0);
269 if (IS_ERR(sfctemp->regs))
270 return PTR_ERR(sfctemp->regs);
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");
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");
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");
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");
292 ret = reset_control_assert(sfctemp->rst_sense);
294 return dev_err_probe(dev, ret, "error asserting sense reset\n");
296 ret = reset_control_assert(sfctemp->rst_bus);
298 return dev_err_probe(dev, ret, "error asserting bus reset\n");
300 ret = devm_add_action(dev, sfctemp_disable_action, sfctemp);
304 ret = sfctemp_enable(sfctemp);
306 return dev_err_probe(dev, ret, "error enabling temperature sensor: %d\n", ret);
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);
313 static const struct of_device_id sfctemp_of_match[] = {
314 { .compatible = "starfive,jh7100-temp" },
315 { .compatible = "starfive,jh7110-temp" },
318 MODULE_DEVICE_TABLE(of, sfctemp_of_match);
320 static struct platform_driver sfctemp_driver = {
321 .probe = sfctemp_probe,
324 .of_match_table = sfctemp_of_match,
327 module_platform_driver(sfctemp_driver);
329 MODULE_AUTHOR("Emil Renner Berthing");
330 MODULE_DESCRIPTION("StarFive JH71x0 temperature sensor driver");
331 MODULE_LICENSE("GPL");