1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Windfarm PowerMac thermal control. SMU based controls
4  *
5  * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
6  *                    <benh@kernel.crashing.org>
7  */
8 
9 #include <linux/types.h>
10 #include <linux/errno.h>
11 #include <linux/kernel.h>
12 #include <linux/delay.h>
13 #include <linux/slab.h>
14 #include <linux/init.h>
15 #include <linux/wait.h>
16 #include <linux/completion.h>
17 #include <asm/prom.h>
18 #include <asm/machdep.h>
19 #include <asm/io.h>
20 #include <asm/sections.h>
21 #include <asm/smu.h>
22 
23 #include "windfarm.h"
24 
25 #define VERSION "0.4"
26 
27 #undef DEBUG
28 
29 #ifdef DEBUG
30 #define DBG(args...)	printk(args)
31 #else
32 #define DBG(args...)	do { } while(0)
33 #endif
34 
35 static int smu_supports_new_fans_ops = 1;
36 
37 /*
38  * SMU fans control object
39  */
40 
41 static LIST_HEAD(smu_fans);
42 
43 struct smu_fan_control {
44 	struct list_head	link;
45 	int    			fan_type;	/* 0 = rpm, 1 = pwm */
46 	u32			reg;		/* index in SMU */
47 	s32			value;		/* current value */
48 	s32			min, max;	/* min/max values */
49 	struct wf_control	ctrl;
50 };
51 #define to_smu_fan(c) container_of(c, struct smu_fan_control, ctrl)
52 
smu_set_fan(int pwm,u8 id,u16 value)53 static int smu_set_fan(int pwm, u8 id, u16 value)
54 {
55 	struct smu_cmd cmd;
56 	u8 buffer[16];
57 	DECLARE_COMPLETION_ONSTACK(comp);
58 	int rc;
59 
60 	/* Fill SMU command structure */
61 	cmd.cmd = SMU_CMD_FAN_COMMAND;
62 
63 	/* The SMU has an "old" and a "new" way of setting the fan speed
64 	 * Unfortunately, I found no reliable way to know which one works
65 	 * on a given machine model. After some investigations it appears
66 	 * that MacOS X just tries the new one, and if it fails fallbacks
67 	 * to the old ones ... Ugh.
68 	 */
69  retry:
70 	if (smu_supports_new_fans_ops) {
71 		buffer[0] = 0x30;
72 		buffer[1] = id;
73 		*((u16 *)(&buffer[2])) = value;
74 		cmd.data_len = 4;
75 	} else {
76 		if (id > 7)
77 			return -EINVAL;
78 		/* Fill argument buffer */
79 		memset(buffer, 0, 16);
80 		buffer[0] = pwm ? 0x10 : 0x00;
81 		buffer[1] = 0x01 << id;
82 		*((u16 *)&buffer[2 + id * 2]) = value;
83 		cmd.data_len = 14;
84 	}
85 
86 	cmd.reply_len = 16;
87 	cmd.data_buf = cmd.reply_buf = buffer;
88 	cmd.status = 0;
89 	cmd.done = smu_done_complete;
90 	cmd.misc = &comp;
91 
92 	rc = smu_queue_cmd(&cmd);
93 	if (rc)
94 		return rc;
95 	wait_for_completion(&comp);
96 
97 	/* Handle fallback (see comment above) */
98 	if (cmd.status != 0 && smu_supports_new_fans_ops) {
99 		printk(KERN_WARNING "windfarm: SMU failed new fan command "
100 		       "falling back to old method\n");
101 		smu_supports_new_fans_ops = 0;
102 		goto retry;
103 	}
104 
105 	return cmd.status;
106 }
107 
smu_fan_release(struct wf_control * ct)108 static void smu_fan_release(struct wf_control *ct)
109 {
110 	struct smu_fan_control *fct = to_smu_fan(ct);
111 
112 	kfree(fct);
113 }
114 
smu_fan_set(struct wf_control * ct,s32 value)115 static int smu_fan_set(struct wf_control *ct, s32 value)
116 {
117 	struct smu_fan_control *fct = to_smu_fan(ct);
118 
119 	if (value < fct->min)
120 		value = fct->min;
121 	if (value > fct->max)
122 		value = fct->max;
123 	fct->value = value;
124 
125 	return smu_set_fan(fct->fan_type, fct->reg, value);
126 }
127 
smu_fan_get(struct wf_control * ct,s32 * value)128 static int smu_fan_get(struct wf_control *ct, s32 *value)
129 {
130 	struct smu_fan_control *fct = to_smu_fan(ct);
131 	*value = fct->value; /* todo: read from SMU */
132 	return 0;
133 }
134 
smu_fan_min(struct wf_control * ct)135 static s32 smu_fan_min(struct wf_control *ct)
136 {
137 	struct smu_fan_control *fct = to_smu_fan(ct);
138 	return fct->min;
139 }
140 
smu_fan_max(struct wf_control * ct)141 static s32 smu_fan_max(struct wf_control *ct)
142 {
143 	struct smu_fan_control *fct = to_smu_fan(ct);
144 	return fct->max;
145 }
146 
147 static const struct wf_control_ops smu_fan_ops = {
148 	.set_value	= smu_fan_set,
149 	.get_value	= smu_fan_get,
150 	.get_min	= smu_fan_min,
151 	.get_max	= smu_fan_max,
152 	.release	= smu_fan_release,
153 	.owner		= THIS_MODULE,
154 };
155 
smu_fan_create(struct device_node * node,int pwm_fan)156 static struct smu_fan_control *smu_fan_create(struct device_node *node,
157 					      int pwm_fan)
158 {
159 	struct smu_fan_control *fct;
160 	const s32 *v;
161 	const u32 *reg;
162 	const char *l;
163 
164 	fct = kmalloc(sizeof(struct smu_fan_control), GFP_KERNEL);
165 	if (fct == NULL)
166 		return NULL;
167 	fct->ctrl.ops = &smu_fan_ops;
168 	l = of_get_property(node, "location", NULL);
169 	if (l == NULL)
170 		goto fail;
171 
172 	fct->fan_type = pwm_fan;
173 	fct->ctrl.type = pwm_fan ? WF_CONTROL_PWM_FAN : WF_CONTROL_RPM_FAN;
174 
175 	/* We use the name & location here the same way we do for SMU sensors,
176 	 * see the comment in windfarm_smu_sensors.c. The locations are a bit
177 	 * less consistent here between the iMac and the desktop models, but
178 	 * that is good enough for our needs for now at least.
179 	 *
180 	 * One problem though is that Apple seem to be inconsistent with case
181 	 * and the kernel doesn't have strcasecmp =P
182 	 */
183 
184 	fct->ctrl.name = NULL;
185 
186 	/* Names used on desktop models */
187 	if (!strcmp(l, "Rear Fan 0") || !strcmp(l, "Rear Fan") ||
188 	    !strcmp(l, "Rear fan 0") || !strcmp(l, "Rear fan") ||
189 	    !strcmp(l, "CPU A EXHAUST"))
190 		fct->ctrl.name = "cpu-rear-fan-0";
191 	else if (!strcmp(l, "Rear Fan 1") || !strcmp(l, "Rear fan 1") ||
192 		 !strcmp(l, "CPU B EXHAUST"))
193 		fct->ctrl.name = "cpu-rear-fan-1";
194 	else if (!strcmp(l, "Front Fan 0") || !strcmp(l, "Front Fan") ||
195 		 !strcmp(l, "Front fan 0") || !strcmp(l, "Front fan") ||
196 		 !strcmp(l, "CPU A INTAKE"))
197 		fct->ctrl.name = "cpu-front-fan-0";
198 	else if (!strcmp(l, "Front Fan 1") || !strcmp(l, "Front fan 1") ||
199 		 !strcmp(l, "CPU B INTAKE"))
200 		fct->ctrl.name = "cpu-front-fan-1";
201 	else if (!strcmp(l, "CPU A PUMP"))
202 		fct->ctrl.name = "cpu-pump-0";
203 	else if (!strcmp(l, "CPU B PUMP"))
204 		fct->ctrl.name = "cpu-pump-1";
205 	else if (!strcmp(l, "Slots Fan") || !strcmp(l, "Slots fan") ||
206 		 !strcmp(l, "EXPANSION SLOTS INTAKE"))
207 		fct->ctrl.name = "slots-fan";
208 	else if (!strcmp(l, "Drive Bay") || !strcmp(l, "Drive bay") ||
209 		 !strcmp(l, "DRIVE BAY A INTAKE"))
210 		fct->ctrl.name = "drive-bay-fan";
211 	else if (!strcmp(l, "BACKSIDE"))
212 		fct->ctrl.name = "backside-fan";
213 
214 	/* Names used on iMac models */
215 	if (!strcmp(l, "System Fan") || !strcmp(l, "System fan"))
216 		fct->ctrl.name = "system-fan";
217 	else if (!strcmp(l, "CPU Fan") || !strcmp(l, "CPU fan"))
218 		fct->ctrl.name = "cpu-fan";
219 	else if (!strcmp(l, "Hard Drive") || !strcmp(l, "Hard drive"))
220 		fct->ctrl.name = "drive-bay-fan";
221 	else if (!strcmp(l, "HDD Fan")) /* seen on iMac G5 iSight */
222 		fct->ctrl.name = "hard-drive-fan";
223 	else if (!strcmp(l, "ODD Fan")) /* same */
224 		fct->ctrl.name = "optical-drive-fan";
225 
226 	/* Unrecognized fan, bail out */
227 	if (fct->ctrl.name == NULL)
228 		goto fail;
229 
230 	/* Get min & max values*/
231 	v = of_get_property(node, "min-value", NULL);
232 	if (v == NULL)
233 		goto fail;
234 	fct->min = *v;
235 	v = of_get_property(node, "max-value", NULL);
236 	if (v == NULL)
237 		goto fail;
238 	fct->max = *v;
239 
240 	/* Get "reg" value */
241 	reg = of_get_property(node, "reg", NULL);
242 	if (reg == NULL)
243 		goto fail;
244 	fct->reg = *reg;
245 
246 	if (wf_register_control(&fct->ctrl))
247 		goto fail;
248 
249 	return fct;
250  fail:
251 	kfree(fct);
252 	return NULL;
253 }
254 
255 
smu_controls_init(void)256 static int __init smu_controls_init(void)
257 {
258 	struct device_node *smu, *fans, *fan;
259 
260 	if (!smu_present())
261 		return -ENODEV;
262 
263 	smu = of_find_node_by_type(NULL, "smu");
264 	if (smu == NULL)
265 		return -ENODEV;
266 
267 	/* Look for RPM fans */
268 	for (fans = NULL; (fans = of_get_next_child(smu, fans)) != NULL;)
269 		if (of_node_name_eq(fans, "rpm-fans") ||
270 		    of_device_is_compatible(fans, "smu-rpm-fans"))
271 			break;
272 	for (fan = NULL;
273 	     fans && (fan = of_get_next_child(fans, fan)) != NULL;) {
274 		struct smu_fan_control *fct;
275 
276 		fct = smu_fan_create(fan, 0);
277 		if (fct == NULL) {
278 			printk(KERN_WARNING "windfarm: Failed to create SMU "
279 			       "RPM fan %pOFn\n", fan);
280 			continue;
281 		}
282 		list_add(&fct->link, &smu_fans);
283 	}
284 	of_node_put(fans);
285 
286 
287 	/* Look for PWM fans */
288 	for (fans = NULL; (fans = of_get_next_child(smu, fans)) != NULL;)
289 		if (of_node_name_eq(fans, "pwm-fans"))
290 			break;
291 	for (fan = NULL;
292 	     fans && (fan = of_get_next_child(fans, fan)) != NULL;) {
293 		struct smu_fan_control *fct;
294 
295 		fct = smu_fan_create(fan, 1);
296 		if (fct == NULL) {
297 			printk(KERN_WARNING "windfarm: Failed to create SMU "
298 			       "PWM fan %pOFn\n", fan);
299 			continue;
300 		}
301 		list_add(&fct->link, &smu_fans);
302 	}
303 	of_node_put(fans);
304 	of_node_put(smu);
305 
306 	return 0;
307 }
308 
smu_controls_exit(void)309 static void __exit smu_controls_exit(void)
310 {
311 	struct smu_fan_control *fct;
312 
313 	while (!list_empty(&smu_fans)) {
314 		fct = list_entry(smu_fans.next, struct smu_fan_control, link);
315 		list_del(&fct->link);
316 		wf_unregister_control(&fct->ctrl);
317 	}
318 }
319 
320 
321 module_init(smu_controls_init);
322 module_exit(smu_controls_exit);
323 
324 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
325 MODULE_DESCRIPTION("SMU control objects for PowerMacs thermal control");
326 MODULE_LICENSE("GPL");
327 
328