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8#include <linux/clk.h>
9#include <linux/debugfs.h>
10#include <linux/device.h>
11#include <linux/err.h>
12#include <linux/io.h>
13#include <linux/kernel.h>
14#include <linux/module.h>
15#include <linux/of.h>
16#include <linux/of_address.h>
17#include <linux/of_device.h>
18#include <linux/platform_device.h>
19#include <linux/thermal.h>
20
21#include "../thermal_hwmon.h"
22
23#define BCM2835_TS_TSENSCTL 0x00
24#define BCM2835_TS_TSENSSTAT 0x04
25
26#define BCM2835_TS_TSENSCTL_PRWDW BIT(0)
27#define BCM2835_TS_TSENSCTL_RSTB BIT(1)
28
29
30
31
32
33#define BCM2835_TS_TSENSCTL_CTRL_BITS 3
34#define BCM2835_TS_TSENSCTL_CTRL_SHIFT 2
35#define BCM2835_TS_TSENSCTL_CTRL_MASK \
36 GENMASK(BCM2835_TS_TSENSCTL_CTRL_BITS + \
37 BCM2835_TS_TSENSCTL_CTRL_SHIFT - 1, \
38 BCM2835_TS_TSENSCTL_CTRL_SHIFT)
39#define BCM2835_TS_TSENSCTL_CTRL_DEFAULT 1
40#define BCM2835_TS_TSENSCTL_EN_INT BIT(5)
41#define BCM2835_TS_TSENSCTL_DIRECT BIT(6)
42#define BCM2835_TS_TSENSCTL_CLR_INT BIT(7)
43#define BCM2835_TS_TSENSCTL_THOLD_SHIFT 8
44#define BCM2835_TS_TSENSCTL_THOLD_BITS 10
45#define BCM2835_TS_TSENSCTL_THOLD_MASK \
46 GENMASK(BCM2835_TS_TSENSCTL_THOLD_BITS + \
47 BCM2835_TS_TSENSCTL_THOLD_SHIFT - 1, \
48 BCM2835_TS_TSENSCTL_THOLD_SHIFT)
49
50
51
52
53#define BCM2835_TS_TSENSCTL_RSTDELAY_SHIFT 18
54#define BCM2835_TS_TSENSCTL_RSTDELAY_BITS 8
55#define BCM2835_TS_TSENSCTL_REGULEN BIT(26)
56
57#define BCM2835_TS_TSENSSTAT_DATA_BITS 10
58#define BCM2835_TS_TSENSSTAT_DATA_SHIFT 0
59#define BCM2835_TS_TSENSSTAT_DATA_MASK \
60 GENMASK(BCM2835_TS_TSENSSTAT_DATA_BITS + \
61 BCM2835_TS_TSENSSTAT_DATA_SHIFT - 1, \
62 BCM2835_TS_TSENSSTAT_DATA_SHIFT)
63#define BCM2835_TS_TSENSSTAT_VALID BIT(10)
64#define BCM2835_TS_TSENSSTAT_INTERRUPT BIT(11)
65
66struct bcm2835_thermal_data {
67 struct thermal_zone_device *tz;
68 void __iomem *regs;
69 struct clk *clk;
70 struct dentry *debugfsdir;
71};
72
73static int bcm2835_thermal_adc2temp(u32 adc, int offset, int slope)
74{
75 return offset + slope * adc;
76}
77
78static int bcm2835_thermal_temp2adc(int temp, int offset, int slope)
79{
80 temp -= offset;
81 temp /= slope;
82
83 if (temp < 0)
84 temp = 0;
85 if (temp >= BIT(BCM2835_TS_TSENSSTAT_DATA_BITS))
86 temp = BIT(BCM2835_TS_TSENSSTAT_DATA_BITS) - 1;
87
88 return temp;
89}
90
91static int bcm2835_thermal_get_temp(void *d, int *temp)
92{
93 struct bcm2835_thermal_data *data = d;
94 u32 val = readl(data->regs + BCM2835_TS_TSENSSTAT);
95
96 if (!(val & BCM2835_TS_TSENSSTAT_VALID))
97 return -EIO;
98
99 val &= BCM2835_TS_TSENSSTAT_DATA_MASK;
100
101 *temp = bcm2835_thermal_adc2temp(
102 val,
103 thermal_zone_get_offset(data->tz),
104 thermal_zone_get_slope(data->tz));
105
106 return 0;
107}
108
109static const struct debugfs_reg32 bcm2835_thermal_regs[] = {
110 {
111 .name = "ctl",
112 .offset = 0
113 },
114 {
115 .name = "stat",
116 .offset = 4
117 }
118};
119
120static void bcm2835_thermal_debugfs(struct platform_device *pdev)
121{
122 struct bcm2835_thermal_data *data = platform_get_drvdata(pdev);
123 struct debugfs_regset32 *regset;
124
125 data->debugfsdir = debugfs_create_dir("bcm2835_thermal", NULL);
126
127 regset = devm_kzalloc(&pdev->dev, sizeof(*regset), GFP_KERNEL);
128 if (!regset)
129 return;
130
131 regset->regs = bcm2835_thermal_regs;
132 regset->nregs = ARRAY_SIZE(bcm2835_thermal_regs);
133 regset->base = data->regs;
134
135 debugfs_create_regset32("regset", 0444, data->debugfsdir, regset);
136}
137
138static const struct thermal_zone_of_device_ops bcm2835_thermal_ops = {
139 .get_temp = bcm2835_thermal_get_temp,
140};
141
142
143
144
145
146
147
148
149
150static const struct of_device_id bcm2835_thermal_of_match_table[] = {
151 {
152 .compatible = "brcm,bcm2835-thermal",
153 },
154 {
155 .compatible = "brcm,bcm2836-thermal",
156 },
157 {
158 .compatible = "brcm,bcm2837-thermal",
159 },
160 {},
161};
162MODULE_DEVICE_TABLE(of, bcm2835_thermal_of_match_table);
163
164static int bcm2835_thermal_probe(struct platform_device *pdev)
165{
166 const struct of_device_id *match;
167 struct thermal_zone_device *tz;
168 struct bcm2835_thermal_data *data;
169 struct resource *res;
170 int err = 0;
171 u32 val;
172 unsigned long rate;
173
174 data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
175 if (!data)
176 return -ENOMEM;
177
178 match = of_match_device(bcm2835_thermal_of_match_table,
179 &pdev->dev);
180 if (!match)
181 return -EINVAL;
182
183 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
184 data->regs = devm_ioremap_resource(&pdev->dev, res);
185 if (IS_ERR(data->regs)) {
186 err = PTR_ERR(data->regs);
187 dev_err(&pdev->dev, "Could not get registers: %d\n", err);
188 return err;
189 }
190
191 data->clk = devm_clk_get(&pdev->dev, NULL);
192 if (IS_ERR(data->clk)) {
193 err = PTR_ERR(data->clk);
194 if (err != -EPROBE_DEFER)
195 dev_err(&pdev->dev, "Could not get clk: %d\n", err);
196 return err;
197 }
198
199 err = clk_prepare_enable(data->clk);
200 if (err)
201 return err;
202
203 rate = clk_get_rate(data->clk);
204 if ((rate < 1920000) || (rate > 5000000))
205 dev_warn(&pdev->dev,
206 "Clock %pCn running at %lu Hz is outside of the recommended range: 1.92 to 5MHz\n",
207 data->clk, rate);
208
209
210 tz = thermal_zone_of_sensor_register(&pdev->dev, 0, data,
211 &bcm2835_thermal_ops);
212 if (IS_ERR(tz)) {
213 err = PTR_ERR(tz);
214 dev_err(&pdev->dev,
215 "Failed to register the thermal device: %d\n",
216 err);
217 goto err_clk;
218 }
219
220
221
222
223
224
225
226 val = readl(data->regs + BCM2835_TS_TSENSCTL);
227 if (!(val & BCM2835_TS_TSENSCTL_RSTB)) {
228 int trip_temp, offset, slope;
229
230 slope = thermal_zone_get_slope(tz);
231 offset = thermal_zone_get_offset(tz);
232
233
234
235
236 err = tz->ops->get_trip_temp(tz, 0, &trip_temp);
237 if (err < 0) {
238 dev_err(&pdev->dev,
239 "Not able to read trip_temp: %d\n",
240 err);
241 goto err_tz;
242 }
243
244
245 val = (BCM2835_TS_TSENSCTL_CTRL_DEFAULT <<
246 BCM2835_TS_TSENSCTL_CTRL_SHIFT) |
247 BCM2835_TS_TSENSCTL_REGULEN;
248
249
250 val |= (0xFE << BCM2835_TS_TSENSCTL_RSTDELAY_SHIFT);
251
252
253 val |= bcm2835_thermal_temp2adc(trip_temp,
254 offset,
255 slope)
256 << BCM2835_TS_TSENSCTL_THOLD_SHIFT;
257
258
259 writel(val, data->regs + BCM2835_TS_TSENSCTL);
260 val |= BCM2835_TS_TSENSCTL_RSTB;
261 writel(val, data->regs + BCM2835_TS_TSENSCTL);
262 }
263
264 data->tz = tz;
265
266 platform_set_drvdata(pdev, data);
267
268
269
270
271
272 tz->tzp->no_hwmon = false;
273 err = thermal_add_hwmon_sysfs(tz);
274 if (err)
275 goto err_tz;
276
277 bcm2835_thermal_debugfs(pdev);
278
279 return 0;
280err_tz:
281 thermal_zone_of_sensor_unregister(&pdev->dev, tz);
282err_clk:
283 clk_disable_unprepare(data->clk);
284
285 return err;
286}
287
288static int bcm2835_thermal_remove(struct platform_device *pdev)
289{
290 struct bcm2835_thermal_data *data = platform_get_drvdata(pdev);
291 struct thermal_zone_device *tz = data->tz;
292
293 debugfs_remove_recursive(data->debugfsdir);
294 thermal_zone_of_sensor_unregister(&pdev->dev, tz);
295 clk_disable_unprepare(data->clk);
296
297 return 0;
298}
299
300static struct platform_driver bcm2835_thermal_driver = {
301 .probe = bcm2835_thermal_probe,
302 .remove = bcm2835_thermal_remove,
303 .driver = {
304 .name = "bcm2835_thermal",
305 .of_match_table = bcm2835_thermal_of_match_table,
306 },
307};
308module_platform_driver(bcm2835_thermal_driver);
309
310MODULE_AUTHOR("Martin Sperl");
311MODULE_DESCRIPTION("Thermal driver for bcm2835 chip");
312MODULE_LICENSE("GPL");
313
