xref: /openbmc/linux/drivers/macintosh/windfarm_smu_controls.c (revision df2634f43f5106947f3735a0b61a6527a4b278cd)
1 /*
2  * Windfarm PowerMac thermal control. SMU based controls
3  *
4  * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
5  *                    <benh@kernel.crashing.org>
6  *
7  * Released under the term of the GNU GPL v2.
8  */
9 
10 #include <linux/types.h>
11 #include <linux/errno.h>
12 #include <linux/kernel.h>
13 #include <linux/delay.h>
14 #include <linux/slab.h>
15 #include <linux/init.h>
16 #include <linux/wait.h>
17 #include <linux/completion.h>
18 #include <asm/prom.h>
19 #include <asm/machdep.h>
20 #include <asm/io.h>
21 #include <asm/system.h>
22 #include <asm/sections.h>
23 #include <asm/smu.h>
24 
25 #include "windfarm.h"
26 
27 #define VERSION "0.4"
28 
29 #undef DEBUG
30 
31 #ifdef DEBUG
32 #define DBG(args...)	printk(args)
33 #else
34 #define DBG(args...)	do { } while(0)
35 #endif
36 
37 static int smu_supports_new_fans_ops = 1;
38 
39 /*
40  * SMU fans control object
41  */
42 
43 static LIST_HEAD(smu_fans);
44 
45 struct smu_fan_control {
46 	struct list_head	link;
47 	int    			fan_type;	/* 0 = rpm, 1 = pwm */
48 	u32			reg;		/* index in SMU */
49 	s32			value;		/* current value */
50 	s32			min, max;	/* min/max values */
51 	struct wf_control	ctrl;
52 };
53 #define to_smu_fan(c) container_of(c, struct smu_fan_control, ctrl)
54 
55 static int smu_set_fan(int pwm, u8 id, u16 value)
56 {
57 	struct smu_cmd cmd;
58 	u8 buffer[16];
59 	DECLARE_COMPLETION_ONSTACK(comp);
60 	int rc;
61 
62 	/* Fill SMU command structure */
63 	cmd.cmd = SMU_CMD_FAN_COMMAND;
64 
65 	/* The SMU has an "old" and a "new" way of setting the fan speed
66 	 * Unfortunately, I found no reliable way to know which one works
67 	 * on a given machine model. After some investigations it appears
68 	 * that MacOS X just tries the new one, and if it fails fallbacks
69 	 * to the old ones ... Ugh.
70 	 */
71  retry:
72 	if (smu_supports_new_fans_ops) {
73 		buffer[0] = 0x30;
74 		buffer[1] = id;
75 		*((u16 *)(&buffer[2])) = value;
76 		cmd.data_len = 4;
77 	} else {
78 		if (id > 7)
79 			return -EINVAL;
80 		/* Fill argument buffer */
81 		memset(buffer, 0, 16);
82 		buffer[0] = pwm ? 0x10 : 0x00;
83 		buffer[1] = 0x01 << id;
84 		*((u16 *)&buffer[2 + id * 2]) = value;
85 		cmd.data_len = 14;
86 	}
87 
88 	cmd.reply_len = 16;
89 	cmd.data_buf = cmd.reply_buf = buffer;
90 	cmd.status = 0;
91 	cmd.done = smu_done_complete;
92 	cmd.misc = &comp;
93 
94 	rc = smu_queue_cmd(&cmd);
95 	if (rc)
96 		return rc;
97 	wait_for_completion(&comp);
98 
99 	/* Handle fallback (see coment above) */
100 	if (cmd.status != 0 && smu_supports_new_fans_ops) {
101 		printk(KERN_WARNING "windfarm: SMU failed new fan command "
102 		       "falling back to old method\n");
103 		smu_supports_new_fans_ops = 0;
104 		goto retry;
105 	}
106 
107 	return cmd.status;
108 }
109 
110 static void smu_fan_release(struct wf_control *ct)
111 {
112 	struct smu_fan_control *fct = to_smu_fan(ct);
113 
114 	kfree(fct);
115 }
116 
117 static int smu_fan_set(struct wf_control *ct, s32 value)
118 {
119 	struct smu_fan_control *fct = to_smu_fan(ct);
120 
121 	if (value < fct->min)
122 		value = fct->min;
123 	if (value > fct->max)
124 		value = fct->max;
125 	fct->value = value;
126 
127 	return smu_set_fan(fct->fan_type, fct->reg, value);
128 }
129 
130 static int smu_fan_get(struct wf_control *ct, s32 *value)
131 {
132 	struct smu_fan_control *fct = to_smu_fan(ct);
133 	*value = fct->value; /* todo: read from SMU */
134 	return 0;
135 }
136 
137 static s32 smu_fan_min(struct wf_control *ct)
138 {
139 	struct smu_fan_control *fct = to_smu_fan(ct);
140 	return fct->min;
141 }
142 
143 static s32 smu_fan_max(struct wf_control *ct)
144 {
145 	struct smu_fan_control *fct = to_smu_fan(ct);
146 	return fct->max;
147 }
148 
149 static struct wf_control_ops smu_fan_ops = {
150 	.set_value	= smu_fan_set,
151 	.get_value	= smu_fan_get,
152 	.get_min	= smu_fan_min,
153 	.get_max	= smu_fan_max,
154 	.release	= smu_fan_release,
155 	.owner		= THIS_MODULE,
156 };
157 
158 static struct smu_fan_control *smu_fan_create(struct device_node *node,
159 					      int pwm_fan)
160 {
161 	struct smu_fan_control *fct;
162 	const s32 *v;
163 	const u32 *reg;
164 	const char *l;
165 
166 	fct = kmalloc(sizeof(struct smu_fan_control), GFP_KERNEL);
167 	if (fct == NULL)
168 		return NULL;
169 	fct->ctrl.ops = &smu_fan_ops;
170 	l = of_get_property(node, "location", NULL);
171 	if (l == NULL)
172 		goto fail;
173 
174 	fct->fan_type = pwm_fan;
175 	fct->ctrl.type = pwm_fan ? WF_CONTROL_PWM_FAN : WF_CONTROL_RPM_FAN;
176 	sysfs_attr_init(&fct->ctrl.attr.attr);
177 
178 	/* We use the name & location here the same way we do for SMU sensors,
179 	 * see the comment in windfarm_smu_sensors.c. The locations are a bit
180 	 * less consistent here between the iMac and the desktop models, but
181 	 * that is good enough for our needs for now at least.
182 	 *
183 	 * One problem though is that Apple seem to be inconsistent with case
184 	 * and the kernel doesn't have strcasecmp =P
185 	 */
186 
187 	fct->ctrl.name = NULL;
188 
189 	/* Names used on desktop models */
190 	if (!strcmp(l, "Rear Fan 0") || !strcmp(l, "Rear Fan") ||
191 	    !strcmp(l, "Rear fan 0") || !strcmp(l, "Rear fan") ||
192 	    !strcmp(l, "CPU A EXHAUST"))
193 		fct->ctrl.name = "cpu-rear-fan-0";
194 	else if (!strcmp(l, "Rear Fan 1") || !strcmp(l, "Rear fan 1") ||
195 		 !strcmp(l, "CPU B EXHAUST"))
196 		fct->ctrl.name = "cpu-rear-fan-1";
197 	else if (!strcmp(l, "Front Fan 0") || !strcmp(l, "Front Fan") ||
198 		 !strcmp(l, "Front fan 0") || !strcmp(l, "Front fan") ||
199 		 !strcmp(l, "CPU A INTAKE"))
200 		fct->ctrl.name = "cpu-front-fan-0";
201 	else if (!strcmp(l, "Front Fan 1") || !strcmp(l, "Front fan 1") ||
202 		 !strcmp(l, "CPU B INTAKE"))
203 		fct->ctrl.name = "cpu-front-fan-1";
204 	else if (!strcmp(l, "CPU A PUMP"))
205 		fct->ctrl.name = "cpu-pump-0";
206 	else if (!strcmp(l, "CPU B PUMP"))
207 		fct->ctrl.name = "cpu-pump-1";
208 	else if (!strcmp(l, "Slots Fan") || !strcmp(l, "Slots fan") ||
209 		 !strcmp(l, "EXPANSION SLOTS INTAKE"))
210 		fct->ctrl.name = "slots-fan";
211 	else if (!strcmp(l, "Drive Bay") || !strcmp(l, "Drive bay") ||
212 		 !strcmp(l, "DRIVE BAY A INTAKE"))
213 		fct->ctrl.name = "drive-bay-fan";
214 	else if (!strcmp(l, "BACKSIDE"))
215 		fct->ctrl.name = "backside-fan";
216 
217 	/* Names used on iMac models */
218 	if (!strcmp(l, "System Fan") || !strcmp(l, "System fan"))
219 		fct->ctrl.name = "system-fan";
220 	else if (!strcmp(l, "CPU Fan") || !strcmp(l, "CPU fan"))
221 		fct->ctrl.name = "cpu-fan";
222 	else if (!strcmp(l, "Hard Drive") || !strcmp(l, "Hard drive"))
223 		fct->ctrl.name = "drive-bay-fan";
224 	else if (!strcmp(l, "HDD Fan")) /* seen on iMac G5 iSight */
225 		fct->ctrl.name = "hard-drive-fan";
226 	else if (!strcmp(l, "ODD Fan")) /* same */
227 		fct->ctrl.name = "optical-drive-fan";
228 
229 	/* Unrecognized fan, bail out */
230 	if (fct->ctrl.name == NULL)
231 		goto fail;
232 
233 	/* Get min & max values*/
234 	v = of_get_property(node, "min-value", NULL);
235 	if (v == NULL)
236 		goto fail;
237 	fct->min = *v;
238 	v = of_get_property(node, "max-value", NULL);
239 	if (v == NULL)
240 		goto fail;
241 	fct->max = *v;
242 
243 	/* Get "reg" value */
244 	reg = of_get_property(node, "reg", NULL);
245 	if (reg == NULL)
246 		goto fail;
247 	fct->reg = *reg;
248 
249 	if (wf_register_control(&fct->ctrl))
250 		goto fail;
251 
252 	return fct;
253  fail:
254 	kfree(fct);
255 	return NULL;
256 }
257 
258 
259 static int __init smu_controls_init(void)
260 {
261 	struct device_node *smu, *fans, *fan;
262 
263 	if (!smu_present())
264 		return -ENODEV;
265 
266 	smu = of_find_node_by_type(NULL, "smu");
267 	if (smu == NULL)
268 		return -ENODEV;
269 
270 	/* Look for RPM fans */
271 	for (fans = NULL; (fans = of_get_next_child(smu, fans)) != NULL;)
272 		if (!strcmp(fans->name, "rpm-fans") ||
273 		    of_device_is_compatible(fans, "smu-rpm-fans"))
274 			break;
275 	for (fan = NULL;
276 	     fans && (fan = of_get_next_child(fans, fan)) != NULL;) {
277 		struct smu_fan_control *fct;
278 
279 		fct = smu_fan_create(fan, 0);
280 		if (fct == NULL) {
281 			printk(KERN_WARNING "windfarm: Failed to create SMU "
282 			       "RPM fan %s\n", fan->name);
283 			continue;
284 		}
285 		list_add(&fct->link, &smu_fans);
286 	}
287 	of_node_put(fans);
288 
289 
290 	/* Look for PWM fans */
291 	for (fans = NULL; (fans = of_get_next_child(smu, fans)) != NULL;)
292 		if (!strcmp(fans->name, "pwm-fans"))
293 			break;
294 	for (fan = NULL;
295 	     fans && (fan = of_get_next_child(fans, fan)) != NULL;) {
296 		struct smu_fan_control *fct;
297 
298 		fct = smu_fan_create(fan, 1);
299 		if (fct == NULL) {
300 			printk(KERN_WARNING "windfarm: Failed to create SMU "
301 			       "PWM fan %s\n", fan->name);
302 			continue;
303 		}
304 		list_add(&fct->link, &smu_fans);
305 	}
306 	of_node_put(fans);
307 	of_node_put(smu);
308 
309 	return 0;
310 }
311 
312 static void __exit smu_controls_exit(void)
313 {
314 	struct smu_fan_control *fct;
315 
316 	while (!list_empty(&smu_fans)) {
317 		fct = list_entry(smu_fans.next, struct smu_fan_control, link);
318 		list_del(&fct->link);
319 		wf_unregister_control(&fct->ctrl);
320 	}
321 }
322 
323 
324 module_init(smu_controls_init);
325 module_exit(smu_controls_exit);
326 
327 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
328 MODULE_DESCRIPTION("SMU control objects for PowerMacs thermal control");
329 MODULE_LICENSE("GPL");
330 
331