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
37static int smu_supports_new_fans_ops = 1;
38
39/*
40 * SMU fans control object
41 */
42
43static LIST_HEAD(smu_fans);
44
45struct 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
55static 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
110static 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
117static 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
130static 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
137static 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
143static 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
149static 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
158static 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
177	/* We use the name & location here the same way we do for SMU sensors,
178	 * see the comment in windfarm_smu_sensors.c. The locations are a bit
179	 * less consistent here between the iMac and the desktop models, but
180	 * that is good enough for our needs for now at least.
181	 *
182	 * One problem though is that Apple seem to be inconsistent with case
183	 * and the kernel doesn't have strcasecmp =P
184	 */
185
186	fct->ctrl.name = NULL;
187
188	/* Names used on desktop models */
189	if (!strcmp(l, "Rear Fan 0") || !strcmp(l, "Rear Fan") ||
190	    !strcmp(l, "Rear fan 0") || !strcmp(l, "Rear fan") ||
191	    !strcmp(l, "CPU A EXHAUST"))
192		fct->ctrl.name = "cpu-rear-fan-0";
193	else if (!strcmp(l, "Rear Fan 1") || !strcmp(l, "Rear fan 1") ||
194		 !strcmp(l, "CPU B EXHAUST"))
195		fct->ctrl.name = "cpu-rear-fan-1";
196	else if (!strcmp(l, "Front Fan 0") || !strcmp(l, "Front Fan") ||
197		 !strcmp(l, "Front fan 0") || !strcmp(l, "Front fan") ||
198		 !strcmp(l, "CPU A INTAKE"))
199		fct->ctrl.name = "cpu-front-fan-0";
200	else if (!strcmp(l, "Front Fan 1") || !strcmp(l, "Front fan 1") ||
201		 !strcmp(l, "CPU B INTAKE"))
202		fct->ctrl.name = "cpu-front-fan-1";
203	else if (!strcmp(l, "CPU A PUMP"))
204		fct->ctrl.name = "cpu-pump-0";
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
222	/* Unrecognized fan, bail out */
223	if (fct->ctrl.name == NULL)
224		goto fail;
225
226	/* Get min & max values*/
227	v = of_get_property(node, "min-value", NULL);
228	if (v == NULL)
229		goto fail;
230	fct->min = *v;
231	v = of_get_property(node, "max-value", NULL);
232	if (v == NULL)
233		goto fail;
234	fct->max = *v;
235
236	/* Get "reg" value */
237	reg = of_get_property(node, "reg", NULL);
238	if (reg == NULL)
239		goto fail;
240	fct->reg = *reg;
241
242	if (wf_register_control(&fct->ctrl))
243		goto fail;
244
245	return fct;
246 fail:
247	kfree(fct);
248	return NULL;
249}
250
251
252static int __init smu_controls_init(void)
253{
254	struct device_node *smu, *fans, *fan;
255
256	if (!smu_present())
257		return -ENODEV;
258
259	smu = of_find_node_by_type(NULL, "smu");
260	if (smu == NULL)
261		return -ENODEV;
262
263	/* Look for RPM fans */
264	for (fans = NULL; (fans = of_get_next_child(smu, fans)) != NULL;)
265		if (!strcmp(fans->name, "rpm-fans") ||
266		    of_device_is_compatible(fans, "smu-rpm-fans"))
267			break;
268	for (fan = NULL;
269	     fans && (fan = of_get_next_child(fans, fan)) != NULL;) {
270		struct smu_fan_control *fct;
271
272		fct = smu_fan_create(fan, 0);
273		if (fct == NULL) {
274			printk(KERN_WARNING "windfarm: Failed to create SMU "
275			       "RPM fan %s\n", fan->name);
276			continue;
277		}
278		list_add(&fct->link, &smu_fans);
279	}
280	of_node_put(fans);
281
282
283	/* Look for PWM fans */
284	for (fans = NULL; (fans = of_get_next_child(smu, fans)) != NULL;)
285		if (!strcmp(fans->name, "pwm-fans"))
286			break;
287	for (fan = NULL;
288	     fans && (fan = of_get_next_child(fans, fan)) != NULL;) {
289		struct smu_fan_control *fct;
290
291		fct = smu_fan_create(fan, 1);
292		if (fct == NULL) {
293			printk(KERN_WARNING "windfarm: Failed to create SMU "
294			       "PWM fan %s\n", fan->name);
295			continue;
296		}
297		list_add(&fct->link, &smu_fans);
298	}
299	of_node_put(fans);
300	of_node_put(smu);
301
302	return 0;
303}
304
305static void __exit smu_controls_exit(void)
306{
307	struct smu_fan_control *fct;
308
309	while (!list_empty(&smu_fans)) {
310		fct = list_entry(smu_fans.next, struct smu_fan_control, link);
311		list_del(&fct->link);
312		wf_unregister_control(&fct->ctrl);
313	}
314}
315
316
317module_init(smu_controls_init);
318module_exit(smu_controls_exit);
319
320MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
321MODULE_DESCRIPTION("SMU control objects for PowerMacs thermal control");
322MODULE_LICENSE("GPL");
323