xref: /linux/arch/mips/alchemy/common/power.c (revision 55fa518867978e1f5fd8353098f80d125ac734d7)
1 /*
2  * BRIEF MODULE DESCRIPTION
3  *	Au1xx0 Power Management routines.
4  *
5  * Copyright 2001, 2008 MontaVista Software Inc.
6  * Author: MontaVista Software, Inc. <source@mvista.com>
7  *
8  *  Some of the routines are right out of init/main.c, whose
9  *  copyrights apply here.
10  *
11  *  This program is free software; you can redistribute	 it and/or modify it
12  *  under  the terms of	 the GNU General  Public License as published by the
13  *  Free Software Foundation;  either version 2 of the	License, or (at your
14  *  option) any later version.
15  *
16  *  THIS  SOFTWARE  IS PROVIDED	  ``AS	IS'' AND   ANY	EXPRESS OR IMPLIED
17  *  WARRANTIES,	  INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
18  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
19  *  NO	EVENT  SHALL   THE AUTHOR  BE	 LIABLE FOR ANY	  DIRECT, INDIRECT,
20  *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  *  NOT LIMITED	  TO, PROCUREMENT OF  SUBSTITUTE GOODS	OR SERVICES; LOSS OF
22  *  USE, DATA,	OR PROFITS; OR	BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
23  *  ANY THEORY OF LIABILITY, WHETHER IN	 CONTRACT, STRICT LIABILITY, OR TORT
24  *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  *
27  *  You should have received a copy of the  GNU General Public License along
28  *  with this program; if not, write  to the Free Software Foundation, Inc.,
29  *  675 Mass Ave, Cambridge, MA 02139, USA.
30  */
31 
32 #include <linux/init.h>
33 #include <linux/pm.h>
34 #include <linux/sysctl.h>
35 #include <linux/jiffies.h>
36 
37 #include <asm/uaccess.h>
38 #include <asm/cacheflush.h>
39 #include <asm/mach-au1x00/au1000.h>
40 
41 #ifdef CONFIG_PM
42 
43 #define DEBUG 1
44 #ifdef	DEBUG
45 #define DPRINTK(fmt, args...)	printk(KERN_DEBUG "%s: " fmt, __func__, ## args)
46 #else
47 #define DPRINTK(fmt, args...)
48 #endif
49 
50 static void au1000_calibrate_delay(void);
51 
52 extern unsigned long save_local_and_disable(int controller);
53 extern void restore_local_and_enable(int controller, unsigned long mask);
54 extern void local_enable_irq(unsigned int irq_nr);
55 
56 static DEFINE_SPINLOCK(pm_lock);
57 
58 /*
59  * We need to save/restore a bunch of core registers that are
60  * either volatile or reset to some state across a processor sleep.
61  * If reading a register doesn't provide a proper result for a
62  * later restore, we have to provide a function for loading that
63  * register and save a copy.
64  *
65  * We only have to save/restore registers that aren't otherwise
66  * done as part of a driver pm_* function.
67  */
68 static unsigned int	sleep_aux_pll_cntrl;
69 static unsigned int	sleep_cpu_pll_cntrl;
70 static unsigned int	sleep_pin_function;
71 static unsigned int	sleep_uart0_inten;
72 static unsigned int	sleep_uart0_fifoctl;
73 static unsigned int	sleep_uart0_linectl;
74 static unsigned int	sleep_uart0_clkdiv;
75 static unsigned int	sleep_uart0_enable;
76 static unsigned int	sleep_usbhost_enable;
77 static unsigned int	sleep_usbdev_enable;
78 static unsigned int	sleep_static_memctlr[4][3];
79 
80 /*
81  * Define this to cause the value you write to /proc/sys/pm/sleep to
82  * set the TOY timer for the amount of time you want to sleep.
83  * This is done mainly for testing, but may be useful in other cases.
84  * The value is number of 32KHz ticks to sleep.
85  */
86 #define SLEEP_TEST_TIMEOUT 1
87 #ifdef	SLEEP_TEST_TIMEOUT
88 static int sleep_ticks;
89 void wakeup_counter0_set(int ticks);
90 #endif
91 
92 static void save_core_regs(void)
93 {
94 	extern void save_au1xxx_intctl(void);
95 	extern void pm_eth0_shutdown(void);
96 
97 	/*
98 	 * Do the serial ports.....these really should be a pm_*
99 	 * registered function by the driver......but of course the
100 	 * standard serial driver doesn't understand our Au1xxx
101 	 * unique registers.
102 	 */
103 	sleep_uart0_inten = au_readl(UART0_ADDR + UART_IER);
104 	sleep_uart0_fifoctl = au_readl(UART0_ADDR + UART_FCR);
105 	sleep_uart0_linectl = au_readl(UART0_ADDR + UART_LCR);
106 	sleep_uart0_clkdiv = au_readl(UART0_ADDR + UART_CLK);
107 	sleep_uart0_enable = au_readl(UART0_ADDR + UART_MOD_CNTRL);
108 
109 	/* Shutdown USB host/device. */
110 	sleep_usbhost_enable = au_readl(USB_HOST_CONFIG);
111 
112 	/* There appears to be some undocumented reset register.... */
113 	au_writel(0, 0xb0100004); au_sync();
114 	au_writel(0, USB_HOST_CONFIG); au_sync();
115 
116 	sleep_usbdev_enable = au_readl(USBD_ENABLE);
117 	au_writel(0, USBD_ENABLE); au_sync();
118 
119 	/* Save interrupt controller state. */
120 	save_au1xxx_intctl();
121 
122 	/* Clocks and PLLs. */
123 	sleep_aux_pll_cntrl = au_readl(SYS_AUXPLL);
124 
125 	/*
126 	 * We don't really need to do this one, but unless we
127 	 * write it again it won't have a valid value if we
128 	 * happen to read it.
129 	 */
130 	sleep_cpu_pll_cntrl = au_readl(SYS_CPUPLL);
131 
132 	sleep_pin_function = au_readl(SYS_PINFUNC);
133 
134 	/* Save the static memory controller configuration. */
135 	sleep_static_memctlr[0][0] = au_readl(MEM_STCFG0);
136 	sleep_static_memctlr[0][1] = au_readl(MEM_STTIME0);
137 	sleep_static_memctlr[0][2] = au_readl(MEM_STADDR0);
138 	sleep_static_memctlr[1][0] = au_readl(MEM_STCFG1);
139 	sleep_static_memctlr[1][1] = au_readl(MEM_STTIME1);
140 	sleep_static_memctlr[1][2] = au_readl(MEM_STADDR1);
141 	sleep_static_memctlr[2][0] = au_readl(MEM_STCFG2);
142 	sleep_static_memctlr[2][1] = au_readl(MEM_STTIME2);
143 	sleep_static_memctlr[2][2] = au_readl(MEM_STADDR2);
144 	sleep_static_memctlr[3][0] = au_readl(MEM_STCFG3);
145 	sleep_static_memctlr[3][1] = au_readl(MEM_STTIME3);
146 	sleep_static_memctlr[3][2] = au_readl(MEM_STADDR3);
147 }
148 
149 static void restore_core_regs(void)
150 {
151 	extern void restore_au1xxx_intctl(void);
152 	extern void wakeup_counter0_adjust(void);
153 
154 	au_writel(sleep_aux_pll_cntrl, SYS_AUXPLL); au_sync();
155 	au_writel(sleep_cpu_pll_cntrl, SYS_CPUPLL); au_sync();
156 	au_writel(sleep_pin_function, SYS_PINFUNC); au_sync();
157 
158 	/* Restore the static memory controller configuration. */
159 	au_writel(sleep_static_memctlr[0][0], MEM_STCFG0);
160 	au_writel(sleep_static_memctlr[0][1], MEM_STTIME0);
161 	au_writel(sleep_static_memctlr[0][2], MEM_STADDR0);
162 	au_writel(sleep_static_memctlr[1][0], MEM_STCFG1);
163 	au_writel(sleep_static_memctlr[1][1], MEM_STTIME1);
164 	au_writel(sleep_static_memctlr[1][2], MEM_STADDR1);
165 	au_writel(sleep_static_memctlr[2][0], MEM_STCFG2);
166 	au_writel(sleep_static_memctlr[2][1], MEM_STTIME2);
167 	au_writel(sleep_static_memctlr[2][2], MEM_STADDR2);
168 	au_writel(sleep_static_memctlr[3][0], MEM_STCFG3);
169 	au_writel(sleep_static_memctlr[3][1], MEM_STTIME3);
170 	au_writel(sleep_static_memctlr[3][2], MEM_STADDR3);
171 
172 	/*
173 	 * Enable the UART if it was enabled before sleep.
174 	 * I guess I should define module control bits........
175 	 */
176 	if (sleep_uart0_enable & 0x02) {
177 		au_writel(0, UART0_ADDR + UART_MOD_CNTRL); au_sync();
178 		au_writel(1, UART0_ADDR + UART_MOD_CNTRL); au_sync();
179 		au_writel(3, UART0_ADDR + UART_MOD_CNTRL); au_sync();
180 		au_writel(sleep_uart0_inten, UART0_ADDR + UART_IER); au_sync();
181 		au_writel(sleep_uart0_fifoctl, UART0_ADDR + UART_FCR); au_sync();
182 		au_writel(sleep_uart0_linectl, UART0_ADDR + UART_LCR); au_sync();
183 		au_writel(sleep_uart0_clkdiv, UART0_ADDR + UART_CLK); au_sync();
184 	}
185 
186 	restore_au1xxx_intctl();
187 	wakeup_counter0_adjust();
188 }
189 
190 unsigned long suspend_mode;
191 
192 void wakeup_from_suspend(void)
193 {
194 	suspend_mode = 0;
195 }
196 
197 int au_sleep(void)
198 {
199 	unsigned long wakeup, flags;
200 	extern void save_and_sleep(void);
201 
202 	spin_lock_irqsave(&pm_lock, flags);
203 
204 	save_core_regs();
205 
206 	flush_cache_all();
207 
208 	/**
209 	 ** The code below is all system dependent and we should probably
210 	 ** have a function call out of here to set this up.  You need
211 	 ** to configure the GPIO or timer interrupts that will bring
212 	 ** you out of sleep.
213 	 ** For testing, the TOY counter wakeup is useful.
214 	 **/
215 #if 0
216 	au_writel(au_readl(SYS_PINSTATERD) & ~(1 << 11), SYS_PINSTATERD);
217 
218 	/* GPIO 6 can cause a wake up event */
219 	wakeup = au_readl(SYS_WAKEMSK);
220 	wakeup &= ~(1 << 8);	/* turn off match20 wakeup */
221 	wakeup |= 1 << 6;	/* turn on  GPIO  6 wakeup */
222 #else
223 	/* For testing, allow match20 to wake us up. */
224 #ifdef SLEEP_TEST_TIMEOUT
225 	wakeup_counter0_set(sleep_ticks);
226 #endif
227 	wakeup = 1 << 8;	/* turn on match20 wakeup   */
228 	wakeup = 0;
229 #endif
230 	au_writel(1, SYS_WAKESRC);	/* clear cause */
231 	au_sync();
232 	au_writel(wakeup, SYS_WAKEMSK);
233 	au_sync();
234 
235 	save_and_sleep();
236 
237 	/*
238 	 * After a wakeup, the cpu vectors back to 0x1fc00000, so
239 	 * it's up to the boot code to get us back here.
240 	 */
241 	restore_core_regs();
242 	spin_unlock_irqrestore(&pm_lock, flags);
243 	return 0;
244 }
245 
246 static int pm_do_sleep(ctl_table *ctl, int write, struct file *file,
247 		       void __user *buffer, size_t *len, loff_t *ppos)
248 {
249 #ifdef SLEEP_TEST_TIMEOUT
250 #define TMPBUFLEN2 16
251 	char buf[TMPBUFLEN2], *p;
252 #endif
253 
254 	if (!write)
255 		*len = 0;
256 	else {
257 #ifdef SLEEP_TEST_TIMEOUT
258 		if (*len > TMPBUFLEN2 - 1)
259 			return -EFAULT;
260 		if (copy_from_user(buf, buffer, *len))
261 			return -EFAULT;
262 		buf[*len] = 0;
263 		p = buf;
264 		sleep_ticks = simple_strtoul(p, &p, 0);
265 #endif
266 
267 		au_sleep();
268 	}
269 	return 0;
270 }
271 
272 static int pm_do_freq(ctl_table *ctl, int write, struct file *file,
273 		      void __user *buffer, size_t *len, loff_t *ppos)
274 {
275 	int retval = 0, i;
276 	unsigned long val, pll;
277 #define TMPBUFLEN 64
278 #define MAX_CPU_FREQ 396
279 	char buf[TMPBUFLEN], *p;
280 	unsigned long flags, intc0_mask, intc1_mask;
281 	unsigned long old_baud_base, old_cpu_freq, old_clk, old_refresh;
282 	unsigned long new_baud_base, new_cpu_freq, new_clk, new_refresh;
283 	unsigned long baud_rate;
284 
285 	spin_lock_irqsave(&pm_lock, flags);
286 	if (!write)
287 		*len = 0;
288 	else {
289 		/* Parse the new frequency */
290 		if (*len > TMPBUFLEN - 1) {
291 			spin_unlock_irqrestore(&pm_lock, flags);
292 			return -EFAULT;
293 		}
294 		if (copy_from_user(buf, buffer, *len)) {
295 			spin_unlock_irqrestore(&pm_lock, flags);
296 			return -EFAULT;
297 		}
298 		buf[*len] = 0;
299 		p = buf;
300 		val = simple_strtoul(p, &p, 0);
301 		if (val > MAX_CPU_FREQ) {
302 			spin_unlock_irqrestore(&pm_lock, flags);
303 			return -EFAULT;
304 		}
305 
306 		pll = val / 12;
307 		if ((pll > 33) || (pll < 7)) {	/* 396 MHz max, 84 MHz min */
308 			/* Revisit this for higher speed CPUs */
309 			spin_unlock_irqrestore(&pm_lock, flags);
310 			return -EFAULT;
311 		}
312 
313 		old_baud_base = get_au1x00_uart_baud_base();
314 		old_cpu_freq = get_au1x00_speed();
315 
316 		new_cpu_freq = pll * 12 * 1000000;
317 	        new_baud_base = (new_cpu_freq / (2 * ((int)(au_readl(SYS_POWERCTRL)
318 							    & 0x03) + 2) * 16));
319 		set_au1x00_speed(new_cpu_freq);
320 		set_au1x00_uart_baud_base(new_baud_base);
321 
322 		old_refresh = au_readl(MEM_SDREFCFG) & 0x1ffffff;
323 		new_refresh = ((old_refresh * new_cpu_freq) / old_cpu_freq) |
324 			      (au_readl(MEM_SDREFCFG) & ~0x1ffffff);
325 
326 		au_writel(pll, SYS_CPUPLL);
327 		au_sync_delay(1);
328 		au_writel(new_refresh, MEM_SDREFCFG);
329 		au_sync_delay(1);
330 
331 		for (i = 0; i < 4; i++)
332 			if (au_readl(UART_BASE + UART_MOD_CNTRL +
333 				     i * 0x00100000) == 3) {
334 				old_clk = au_readl(UART_BASE + UART_CLK +
335 						   i * 0x00100000);
336 				baud_rate = old_baud_base / old_clk;
337 				/*
338 				 * We won't get an exact baud rate and the error
339 				 * could be significant enough that our new
340 				 * calculation will result in a clock that will
341 				 * give us a baud rate that's too far off from
342 				 * what we really want.
343 				 */
344 				if (baud_rate > 100000)
345 					baud_rate = 115200;
346 				else if (baud_rate > 50000)
347 					baud_rate = 57600;
348 				else if (baud_rate > 30000)
349 					baud_rate = 38400;
350 				else if (baud_rate > 17000)
351 					baud_rate = 19200;
352 				else
353 					baud_rate = 9600;
354 				new_clk = new_baud_base / baud_rate;
355 				au_writel(new_clk, UART_BASE + UART_CLK +
356 					  i * 0x00100000);
357 				au_sync_delay(10);
358 			}
359 	}
360 
361 	/*
362 	 * We don't want _any_ interrupts other than match20. Otherwise our
363 	 * au1000_calibrate_delay() calculation will be off, potentially a lot.
364 	 */
365 	intc0_mask = save_local_and_disable(0);
366 	intc1_mask = save_local_and_disable(1);
367 	local_enable_irq(AU1000_TOY_MATCH2_INT);
368 	spin_unlock_irqrestore(&pm_lock, flags);
369 	au1000_calibrate_delay();
370 	restore_local_and_enable(0, intc0_mask);
371 	restore_local_and_enable(1, intc1_mask);
372 
373 	return retval;
374 }
375 
376 
377 static struct ctl_table pm_table[] = {
378 	{
379 		.ctl_name	= CTL_UNNUMBERED,
380 		.procname	= "sleep",
381 		.data		= NULL,
382 		.maxlen		= 0,
383 		.mode		= 0600,
384 		.proc_handler	= &pm_do_sleep
385 	},
386 	{
387 		.ctl_name	= CTL_UNNUMBERED,
388 		.procname	= "freq",
389 		.data		= NULL,
390 		.maxlen		= 0,
391 		.mode		= 0600,
392 		.proc_handler	= &pm_do_freq
393 	},
394 	{}
395 };
396 
397 static struct ctl_table pm_dir_table[] = {
398 	{
399 		.ctl_name	= CTL_UNNUMBERED,
400 		.procname	= "pm",
401 		.mode		= 0555,
402 		.child		= pm_table
403 	},
404 	{}
405 };
406 
407 /*
408  * Initialize power interface
409  */
410 static int __init pm_init(void)
411 {
412 	register_sysctl_table(pm_dir_table);
413 	return 0;
414 }
415 
416 __initcall(pm_init);
417 
418 /*
419  * This is right out of init/main.c
420  */
421 
422 /*
423  * This is the number of bits of precision for the loops_per_jiffy.
424  * Each bit takes on average 1.5/HZ seconds.  This (like the original)
425  * is a little better than 1%.
426  */
427 #define LPS_PREC 8
428 
429 static void au1000_calibrate_delay(void)
430 {
431 	unsigned long ticks, loopbit;
432 	int lps_precision = LPS_PREC;
433 
434 	loops_per_jiffy = 1 << 12;
435 
436 	while (loops_per_jiffy <<= 1) {
437 		/* Wait for "start of" clock tick */
438 		ticks = jiffies;
439 		while (ticks == jiffies)
440 			/* nothing */ ;
441 		/* Go ... */
442 		ticks = jiffies;
443 		__delay(loops_per_jiffy);
444 		ticks = jiffies - ticks;
445 		if (ticks)
446 			break;
447 	}
448 
449 	/*
450 	 * Do a binary approximation to get loops_per_jiffy set to be equal
451 	 * one clock (up to lps_precision bits)
452 	 */
453 	loops_per_jiffy >>= 1;
454 	loopbit = loops_per_jiffy;
455 	while (lps_precision-- && (loopbit >>= 1)) {
456 		loops_per_jiffy |= loopbit;
457 		ticks = jiffies;
458 		while (ticks == jiffies);
459 		ticks = jiffies;
460 		__delay(loops_per_jiffy);
461 		if (jiffies != ticks)	/* longer than 1 tick */
462 			loops_per_jiffy &= ~loopbit;
463 	}
464 }
465 #endif	/* CONFIG_PM */
466