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1 /*
2  * omap-pm-noop.c - OMAP power management interface - dummy version
3  *
4  * This code implements the OMAP power management interface to
5  * drivers, CPUIdle, CPUFreq, and DSP Bridge.  It is strictly for
6  * debug/demonstration use, as it does nothing but printk() whenever a
7  * function is called (when DEBUG is defined, below)
8  *
9  * Copyright (C) 2008-2009 Texas Instruments, Inc.
10  * Copyright (C) 2008-2009 Nokia Corporation
11  * Paul Walmsley
12  *
13  * Interface developed by (in alphabetical order):
14  * Karthik Dasu, Tony Lindgren, Rajendra Nayak, Sakari Poussa, Veeramanikandan
15  * Raju, Anand Sawant, Igor Stoppa, Paul Walmsley, Richard Woodruff
16  */
17 
18 #undef DEBUG
19 
20 #include <linux/init.h>
21 #include <linux/cpufreq.h>
22 #include <linux/device.h>
23 #include <linux/platform_device.h>
24 
25 #include "omap_device.h"
26 #include "omap-pm.h"
27 
28 static bool off_mode_enabled;
29 static int dummy_context_loss_counter;
30 
31 /*
32  * Device-driver-originated constraints (via board-*.c files)
33  */
34 
omap_pm_set_max_mpu_wakeup_lat(struct device * dev,long t)35 int omap_pm_set_max_mpu_wakeup_lat(struct device *dev, long t)
36 {
37 	if (!dev || t < -1) {
38 		WARN(1, "OMAP PM: %s: invalid parameter(s)", __func__);
39 		return -EINVAL;
40 	}
41 
42 	if (t == -1)
43 		pr_debug("OMAP PM: remove max MPU wakeup latency constraint: dev %s\n",
44 			 dev_name(dev));
45 	else
46 		pr_debug("OMAP PM: add max MPU wakeup latency constraint: dev %s, t = %ld usec\n",
47 			 dev_name(dev), t);
48 
49 	/*
50 	 * For current Linux, this needs to map the MPU to a
51 	 * powerdomain, then go through the list of current max lat
52 	 * constraints on the MPU and find the smallest.  If
53 	 * the latency constraint has changed, the code should
54 	 * recompute the state to enter for the next powerdomain
55 	 * state.
56 	 *
57 	 * TI CDP code can call constraint_set here.
58 	 */
59 
60 	return 0;
61 }
62 
omap_pm_set_min_bus_tput(struct device * dev,u8 agent_id,unsigned long r)63 int omap_pm_set_min_bus_tput(struct device *dev, u8 agent_id, unsigned long r)
64 {
65 	if (!dev || (agent_id != OCP_INITIATOR_AGENT &&
66 	    agent_id != OCP_TARGET_AGENT)) {
67 		WARN(1, "OMAP PM: %s: invalid parameter(s)", __func__);
68 		return -EINVAL;
69 	}
70 
71 	if (r == 0)
72 		pr_debug("OMAP PM: remove min bus tput constraint: dev %s for agent_id %d\n",
73 			 dev_name(dev), agent_id);
74 	else
75 		pr_debug("OMAP PM: add min bus tput constraint: dev %s for agent_id %d: rate %ld KiB\n",
76 			 dev_name(dev), agent_id, r);
77 
78 	/*
79 	 * This code should model the interconnect and compute the
80 	 * required clock frequency, convert that to a VDD2 OPP ID, then
81 	 * set the VDD2 OPP appropriately.
82 	 *
83 	 * TI CDP code can call constraint_set here on the VDD2 OPP.
84 	 */
85 
86 	return 0;
87 }
88 
omap_pm_set_max_dev_wakeup_lat(struct device * req_dev,struct device * dev,long t)89 int omap_pm_set_max_dev_wakeup_lat(struct device *req_dev, struct device *dev,
90 				   long t)
91 {
92 	if (!req_dev || !dev || t < -1) {
93 		WARN(1, "OMAP PM: %s: invalid parameter(s)", __func__);
94 		return -EINVAL;
95 	}
96 
97 	if (t == -1)
98 		pr_debug("OMAP PM: remove max device latency constraint: dev %s\n",
99 			 dev_name(dev));
100 	else
101 		pr_debug("OMAP PM: add max device latency constraint: dev %s, t = %ld usec\n",
102 			 dev_name(dev), t);
103 
104 	/*
105 	 * For current Linux, this needs to map the device to a
106 	 * powerdomain, then go through the list of current max lat
107 	 * constraints on that powerdomain and find the smallest.  If
108 	 * the latency constraint has changed, the code should
109 	 * recompute the state to enter for the next powerdomain
110 	 * state.  Conceivably, this code should also determine
111 	 * whether to actually disable the device clocks or not,
112 	 * depending on how long it takes to re-enable the clocks.
113 	 *
114 	 * TI CDP code can call constraint_set here.
115 	 */
116 
117 	return 0;
118 }
119 
omap_pm_set_max_sdma_lat(struct device * dev,long t)120 int omap_pm_set_max_sdma_lat(struct device *dev, long t)
121 {
122 	if (!dev || t < -1) {
123 		WARN(1, "OMAP PM: %s: invalid parameter(s)", __func__);
124 		return -EINVAL;
125 	}
126 
127 	if (t == -1)
128 		pr_debug("OMAP PM: remove max DMA latency constraint: dev %s\n",
129 			 dev_name(dev));
130 	else
131 		pr_debug("OMAP PM: add max DMA latency constraint: dev %s, t = %ld usec\n",
132 			 dev_name(dev), t);
133 
134 	/*
135 	 * For current Linux PM QOS params, this code should scan the
136 	 * list of maximum CPU and DMA latencies and select the
137 	 * smallest, then set cpu_dma_latency pm_qos_param
138 	 * accordingly.
139 	 *
140 	 * For future Linux PM QOS params, with separate CPU and DMA
141 	 * latency params, this code should just set the dma_latency param.
142 	 *
143 	 * TI CDP code can call constraint_set here.
144 	 */
145 
146 	return 0;
147 }
148 
omap_pm_set_min_clk_rate(struct device * dev,struct clk * c,long r)149 int omap_pm_set_min_clk_rate(struct device *dev, struct clk *c, long r)
150 {
151 	if (!dev || !c || r < 0) {
152 		WARN(1, "OMAP PM: %s: invalid parameter(s)", __func__);
153 		return -EINVAL;
154 	}
155 
156 	if (r == 0)
157 		pr_debug("OMAP PM: remove min clk rate constraint: dev %s\n",
158 			 dev_name(dev));
159 	else
160 		pr_debug("OMAP PM: add min clk rate constraint: dev %s, rate = %ld Hz\n",
161 			 dev_name(dev), r);
162 
163 	/*
164 	 * Code in a real implementation should keep track of these
165 	 * constraints on the clock, and determine the highest minimum
166 	 * clock rate.  It should iterate over each OPP and determine
167 	 * whether the OPP will result in a clock rate that would
168 	 * satisfy this constraint (and any other PM constraint in effect
169 	 * at that time).  Once it finds the lowest-voltage OPP that
170 	 * meets those conditions, it should switch to it, or return
171 	 * an error if the code is not capable of doing so.
172 	 */
173 
174 	return 0;
175 }
176 
177 /*
178  * DSP Bridge-specific constraints
179  */
180 
omap_pm_dsp_get_opp_table(void)181 const struct omap_opp *omap_pm_dsp_get_opp_table(void)
182 {
183 	pr_debug("OMAP PM: DSP request for OPP table\n");
184 
185 	/*
186 	 * Return DSP frequency table here:  The final item in the
187 	 * array should have .rate = .opp_id = 0.
188 	 */
189 
190 	return NULL;
191 }
192 
omap_pm_dsp_set_min_opp(u8 opp_id)193 void omap_pm_dsp_set_min_opp(u8 opp_id)
194 {
195 	if (opp_id == 0) {
196 		WARN_ON(1);
197 		return;
198 	}
199 
200 	pr_debug("OMAP PM: DSP requests minimum VDD1 OPP to be %d\n", opp_id);
201 
202 	/*
203 	 *
204 	 * For l-o dev tree, our VDD1 clk is keyed on OPP ID, so we
205 	 * can just test to see which is higher, the CPU's desired OPP
206 	 * ID or the DSP's desired OPP ID, and use whichever is
207 	 * highest.
208 	 *
209 	 * In CDP12.14+, the VDD1 OPP custom clock that controls the DSP
210 	 * rate is keyed on MPU speed, not the OPP ID.  So we need to
211 	 * map the OPP ID to the MPU speed for use with clk_set_rate()
212 	 * if it is higher than the current OPP clock rate.
213 	 *
214 	 */
215 }
216 
217 
omap_pm_dsp_get_opp(void)218 u8 omap_pm_dsp_get_opp(void)
219 {
220 	pr_debug("OMAP PM: DSP requests current DSP OPP ID\n");
221 
222 	/*
223 	 * For l-o dev tree, call clk_get_rate() on VDD1 OPP clock
224 	 *
225 	 * CDP12.14+:
226 	 * Call clk_get_rate() on the OPP custom clock, map that to an
227 	 * OPP ID using the tables defined in board-*.c/chip-*.c files.
228 	 */
229 
230 	return 0;
231 }
232 
233 /*
234  * CPUFreq-originated constraint
235  *
236  * In the future, this should be handled by custom OPP clocktype
237  * functions.
238  */
239 
omap_pm_cpu_get_freq_table(void)240 struct cpufreq_frequency_table **omap_pm_cpu_get_freq_table(void)
241 {
242 	pr_debug("OMAP PM: CPUFreq request for frequency table\n");
243 
244 	/*
245 	 * Return CPUFreq frequency table here: loop over
246 	 * all VDD1 clkrates, pull out the mpu_ck frequencies, build
247 	 * table
248 	 */
249 
250 	return NULL;
251 }
252 
omap_pm_cpu_set_freq(unsigned long f)253 void omap_pm_cpu_set_freq(unsigned long f)
254 {
255 	if (f == 0) {
256 		WARN_ON(1);
257 		return;
258 	}
259 
260 	pr_debug("OMAP PM: CPUFreq requests CPU frequency to be set to %lu\n",
261 		 f);
262 
263 	/*
264 	 * For l-o dev tree, determine whether MPU freq or DSP OPP id
265 	 * freq is higher.  Find the OPP ID corresponding to the
266 	 * higher frequency.  Call clk_round_rate() and clk_set_rate()
267 	 * on the OPP custom clock.
268 	 *
269 	 * CDP should just be able to set the VDD1 OPP clock rate here.
270 	 */
271 }
272 
omap_pm_cpu_get_freq(void)273 unsigned long omap_pm_cpu_get_freq(void)
274 {
275 	pr_debug("OMAP PM: CPUFreq requests current CPU frequency\n");
276 
277 	/*
278 	 * Call clk_get_rate() on the mpu_ck.
279 	 */
280 
281 	return 0;
282 }
283 
284 /**
285  * omap_pm_enable_off_mode - notify OMAP PM that off-mode is enabled
286  *
287  * Intended for use only by OMAP PM core code to notify this layer
288  * that off mode has been enabled.
289  */
omap_pm_enable_off_mode(void)290 void omap_pm_enable_off_mode(void)
291 {
292 	off_mode_enabled = true;
293 }
294 
295 /**
296  * omap_pm_disable_off_mode - notify OMAP PM that off-mode is disabled
297  *
298  * Intended for use only by OMAP PM core code to notify this layer
299  * that off mode has been disabled.
300  */
omap_pm_disable_off_mode(void)301 void omap_pm_disable_off_mode(void)
302 {
303 	off_mode_enabled = false;
304 }
305 
306 /*
307  * Device context loss tracking
308  */
309 
310 #ifdef CONFIG_ARCH_OMAP2PLUS
311 
omap_pm_get_dev_context_loss_count(struct device * dev)312 int omap_pm_get_dev_context_loss_count(struct device *dev)
313 {
314 	struct platform_device *pdev = to_platform_device(dev);
315 	int count;
316 
317 	if (WARN_ON(!dev))
318 		return -ENODEV;
319 
320 	if (dev->pm_domain == &omap_device_pm_domain) {
321 		count = omap_device_get_context_loss_count(pdev);
322 	} else {
323 		WARN_ONCE(off_mode_enabled, "omap_pm: using dummy context loss counter; device %s should be converted to omap_device",
324 			  dev_name(dev));
325 
326 		count = dummy_context_loss_counter;
327 
328 		if (off_mode_enabled) {
329 			count++;
330 			/*
331 			 * Context loss count has to be a non-negative value.
332 			 * Clear the sign bit to get a value range from 0 to
333 			 * INT_MAX.
334 			 */
335 			count &= INT_MAX;
336 			dummy_context_loss_counter = count;
337 		}
338 	}
339 
340 	pr_debug("OMAP PM: context loss count for dev %s = %d\n",
341 		 dev_name(dev), count);
342 
343 	return count;
344 }
345 
346 #else
347 
omap_pm_get_dev_context_loss_count(struct device * dev)348 int omap_pm_get_dev_context_loss_count(struct device *dev)
349 {
350 	return dummy_context_loss_counter;
351 }
352 
353 #endif
354 
355 /* Should be called before clk framework init */
omap_pm_if_early_init(void)356 int __init omap_pm_if_early_init(void)
357 {
358 	return 0;
359 }
360 
361 /* Must be called after clock framework is initialized */
omap_pm_if_init(void)362 int __init omap_pm_if_init(void)
363 {
364 	return 0;
365 }
366 
omap_pm_if_exit(void)367 void omap_pm_if_exit(void)
368 {
369 	/* Deallocate CPUFreq frequency table here */
370 }
371 
372