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1 | /* |
2 | * R-Car THS/TSC thermal sensor driver | |
3 | * | |
4 | * Copyright (C) 2012 Renesas Solutions Corp. | |
5 | * Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License as published by | |
9 | * the Free Software Foundation; version 2 of the License. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, but | |
12 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | * General Public License for more details. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public License along | |
17 | * with this program; if not, write to the Free Software Foundation, Inc., | |
18 | * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. | |
19 | */ | |
20 | #include <linux/delay.h> | |
21 | #include <linux/err.h> | |
22 | #include <linux/io.h> | |
23 | #include <linux/module.h> | |
24 | #include <linux/platform_device.h> | |
25 | #include <linux/slab.h> | |
26 | #include <linux/spinlock.h> | |
27 | #include <linux/thermal.h> | |
28 | ||
29 | #define THSCR 0x2c | |
30 | #define THSSR 0x30 | |
31 | ||
32 | /* THSCR */ | |
33 | #define CPTAP 0xf | |
34 | ||
35 | /* THSSR */ | |
36 | #define CTEMP 0x3f | |
37 | ||
38 | ||
39 | struct rcar_thermal_priv { | |
40 | void __iomem *base; | |
41 | struct device *dev; | |
42 | spinlock_t lock; | |
43 | u32 comp; | |
44 | }; | |
45 | ||
46 | /* | |
47 | * basic functions | |
48 | */ | |
49 | static u32 rcar_thermal_read(struct rcar_thermal_priv *priv, u32 reg) | |
50 | { | |
51 | unsigned long flags; | |
52 | u32 ret; | |
53 | ||
54 | spin_lock_irqsave(&priv->lock, flags); | |
55 | ||
56 | ret = ioread32(priv->base + reg); | |
57 | ||
58 | spin_unlock_irqrestore(&priv->lock, flags); | |
59 | ||
60 | return ret; | |
61 | } | |
62 | ||
63 | #if 0 /* no user at this point */ | |
64 | static void rcar_thermal_write(struct rcar_thermal_priv *priv, | |
65 | u32 reg, u32 data) | |
66 | { | |
67 | unsigned long flags; | |
68 | ||
69 | spin_lock_irqsave(&priv->lock, flags); | |
70 | ||
71 | iowrite32(data, priv->base + reg); | |
72 | ||
73 | spin_unlock_irqrestore(&priv->lock, flags); | |
74 | } | |
75 | #endif | |
76 | ||
77 | static void rcar_thermal_bset(struct rcar_thermal_priv *priv, u32 reg, | |
78 | u32 mask, u32 data) | |
79 | { | |
80 | unsigned long flags; | |
81 | u32 val; | |
82 | ||
83 | spin_lock_irqsave(&priv->lock, flags); | |
84 | ||
85 | val = ioread32(priv->base + reg); | |
86 | val &= ~mask; | |
87 | val |= (data & mask); | |
88 | iowrite32(val, priv->base + reg); | |
89 | ||
90 | spin_unlock_irqrestore(&priv->lock, flags); | |
91 | } | |
92 | ||
93 | /* | |
94 | * zone device functions | |
95 | */ | |
96 | static int rcar_thermal_get_temp(struct thermal_zone_device *zone, | |
97 | unsigned long *temp) | |
98 | { | |
99 | struct rcar_thermal_priv *priv = zone->devdata; | |
100 | int val, min, max, tmp; | |
101 | ||
102 | tmp = -200; /* default */ | |
103 | while (1) { | |
104 | if (priv->comp < 1 || priv->comp > 12) { | |
105 | dev_err(priv->dev, | |
106 | "THSSR invalid data (%d)\n", priv->comp); | |
107 | priv->comp = 4; /* for next thermal */ | |
108 | return -EINVAL; | |
109 | } | |
110 | ||
111 | /* | |
112 | * THS comparator offset and the reference temperature | |
113 | * | |
114 | * Comparator | reference | Temperature field | |
115 | * offset | temperature | measurement | |
116 | * | (degrees C) | (degrees C) | |
117 | * -------------+---------------+------------------- | |
118 | * 1 | -45 | -45 to -30 | |
119 | * 2 | -30 | -30 to -15 | |
120 | * 3 | -15 | -15 to 0 | |
121 | * 4 | 0 | 0 to +15 | |
122 | * 5 | +15 | +15 to +30 | |
123 | * 6 | +30 | +30 to +45 | |
124 | * 7 | +45 | +45 to +60 | |
125 | * 8 | +60 | +60 to +75 | |
126 | * 9 | +75 | +75 to +90 | |
127 | * 10 | +90 | +90 to +105 | |
128 | * 11 | +105 | +105 to +120 | |
129 | * 12 | +120 | +120 to +135 | |
130 | */ | |
131 | ||
132 | /* calculate thermal limitation */ | |
133 | min = (priv->comp * 15) - 60; | |
134 | max = min + 15; | |
135 | ||
136 | /* | |
137 | * we need to wait 300us after changing comparator offset | |
138 | * to get stable temperature. | |
139 | * see "Usage Notes" on datasheet | |
140 | */ | |
141 | rcar_thermal_bset(priv, THSCR, CPTAP, priv->comp); | |
142 | udelay(300); | |
143 | ||
144 | /* calculate current temperature */ | |
145 | val = rcar_thermal_read(priv, THSSR) & CTEMP; | |
146 | val = (val * 5) - 65; | |
147 | ||
148 | dev_dbg(priv->dev, "comp/min/max/val = %d/%d/%d/%d\n", | |
149 | priv->comp, min, max, val); | |
150 | ||
151 | /* | |
152 | * If val is same as min/max, then, | |
153 | * it should try again on next comparator. | |
154 | * But the val might be correct temperature. | |
155 | * Keep it on "tmp" and compare with next val. | |
156 | */ | |
157 | if (tmp == val) | |
158 | break; | |
159 | ||
160 | if (val <= min) { | |
161 | tmp = min; | |
162 | priv->comp--; /* try again */ | |
163 | } else if (val >= max) { | |
164 | tmp = max; | |
165 | priv->comp++; /* try again */ | |
166 | } else { | |
167 | tmp = val; | |
168 | break; | |
169 | } | |
170 | } | |
171 | ||
172 | *temp = tmp; | |
173 | return 0; | |
174 | } | |
175 | ||
176 | static struct thermal_zone_device_ops rcar_thermal_zone_ops = { | |
177 | .get_temp = rcar_thermal_get_temp, | |
178 | }; | |
179 | ||
180 | /* | |
181 | * platform functions | |
182 | */ | |
183 | static int rcar_thermal_probe(struct platform_device *pdev) | |
184 | { | |
185 | struct thermal_zone_device *zone; | |
186 | struct rcar_thermal_priv *priv; | |
187 | struct resource *res; | |
188 | int ret; | |
189 | ||
190 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
191 | if (!res) { | |
192 | dev_err(&pdev->dev, "Could not get platform resource\n"); | |
193 | return -ENODEV; | |
194 | } | |
195 | ||
196 | priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); | |
197 | if (!priv) { | |
198 | dev_err(&pdev->dev, "Could not allocate priv\n"); | |
199 | return -ENOMEM; | |
200 | } | |
201 | ||
202 | priv->comp = 4; /* basic setup */ | |
203 | priv->dev = &pdev->dev; | |
204 | spin_lock_init(&priv->lock); | |
205 | priv->base = devm_ioremap_nocache(&pdev->dev, | |
206 | res->start, resource_size(res)); | |
207 | if (!priv->base) { | |
208 | dev_err(&pdev->dev, "Unable to ioremap thermal register\n"); | |
209 | ret = -ENOMEM; | |
210 | goto error_free_priv; | |
211 | } | |
212 | ||
213 | zone = thermal_zone_device_register("rcar_thermal", 0, priv, | |
214 | &rcar_thermal_zone_ops, 0, 0); | |
215 | if (IS_ERR(zone)) { | |
216 | dev_err(&pdev->dev, "thermal zone device is NULL\n"); | |
217 | ret = PTR_ERR(zone); | |
218 | goto error_iounmap; | |
219 | } | |
220 | ||
221 | platform_set_drvdata(pdev, zone); | |
222 | ||
223 | dev_info(&pdev->dev, "proved\n"); | |
224 | ||
225 | return 0; | |
226 | ||
227 | error_iounmap: | |
228 | devm_iounmap(&pdev->dev, priv->base); | |
229 | error_free_priv: | |
230 | devm_kfree(&pdev->dev, priv); | |
231 | ||
232 | return ret; | |
233 | } | |
234 | ||
235 | static int rcar_thermal_remove(struct platform_device *pdev) | |
236 | { | |
237 | struct thermal_zone_device *zone = platform_get_drvdata(pdev); | |
238 | struct rcar_thermal_priv *priv = zone->devdata; | |
239 | ||
240 | thermal_zone_device_unregister(zone); | |
241 | platform_set_drvdata(pdev, NULL); | |
242 | ||
243 | devm_iounmap(&pdev->dev, priv->base); | |
244 | devm_kfree(&pdev->dev, priv); | |
245 | ||
246 | return 0; | |
247 | } | |
248 | ||
249 | static struct platform_driver rcar_thermal_driver = { | |
250 | .driver = { | |
251 | .name = "rcar_thermal", | |
252 | }, | |
253 | .probe = rcar_thermal_probe, | |
254 | .remove = rcar_thermal_remove, | |
255 | }; | |
256 | module_platform_driver(rcar_thermal_driver); | |
257 | ||
258 | MODULE_LICENSE("GPL"); | |
259 | MODULE_DESCRIPTION("R-Car THS/TSC thermal sensor driver"); | |
260 | MODULE_AUTHOR("Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>"); |