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