xref: /openbmc/linux/arch/mips/alchemy/common/power.c (revision 842ed298)
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/pm.h>
33 #include <linux/sysctl.h>
34 #include <linux/jiffies.h>
35 
36 #include <linux/uaccess.h>
37 #include <asm/mach-au1x00/au1000.h>
38 
39 /*
40  * We need to save/restore a bunch of core registers that are
41  * either volatile or reset to some state across a processor sleep.
42  * If reading a register doesn't provide a proper result for a
43  * later restore, we have to provide a function for loading that
44  * register and save a copy.
45  *
46  * We only have to save/restore registers that aren't otherwise
47  * done as part of a driver pm_* function.
48  */
49 static unsigned int sleep_sys_clocks[5];
50 static unsigned int sleep_sys_pinfunc;
51 static unsigned int sleep_static_memctlr[4][3];
52 
53 
54 static void save_core_regs(void)
55 {
56 	/* Clocks and PLLs. */
57 	sleep_sys_clocks[0] = alchemy_rdsys(AU1000_SYS_FREQCTRL0);
58 	sleep_sys_clocks[1] = alchemy_rdsys(AU1000_SYS_FREQCTRL1);
59 	sleep_sys_clocks[2] = alchemy_rdsys(AU1000_SYS_CLKSRC);
60 	sleep_sys_clocks[3] = alchemy_rdsys(AU1000_SYS_CPUPLL);
61 	sleep_sys_clocks[4] = alchemy_rdsys(AU1000_SYS_AUXPLL);
62 
63 	/* pin mux config */
64 	sleep_sys_pinfunc = alchemy_rdsys(AU1000_SYS_PINFUNC);
65 
66 	/* Save the static memory controller configuration. */
67 	sleep_static_memctlr[0][0] = alchemy_rdsmem(AU1000_MEM_STCFG0);
68 	sleep_static_memctlr[0][1] = alchemy_rdsmem(AU1000_MEM_STTIME0);
69 	sleep_static_memctlr[0][2] = alchemy_rdsmem(AU1000_MEM_STADDR0);
70 	sleep_static_memctlr[1][0] = alchemy_rdsmem(AU1000_MEM_STCFG1);
71 	sleep_static_memctlr[1][1] = alchemy_rdsmem(AU1000_MEM_STTIME1);
72 	sleep_static_memctlr[1][2] = alchemy_rdsmem(AU1000_MEM_STADDR1);
73 	sleep_static_memctlr[2][0] = alchemy_rdsmem(AU1000_MEM_STCFG2);
74 	sleep_static_memctlr[2][1] = alchemy_rdsmem(AU1000_MEM_STTIME2);
75 	sleep_static_memctlr[2][2] = alchemy_rdsmem(AU1000_MEM_STADDR2);
76 	sleep_static_memctlr[3][0] = alchemy_rdsmem(AU1000_MEM_STCFG3);
77 	sleep_static_memctlr[3][1] = alchemy_rdsmem(AU1000_MEM_STTIME3);
78 	sleep_static_memctlr[3][2] = alchemy_rdsmem(AU1000_MEM_STADDR3);
79 }
80 
81 static void restore_core_regs(void)
82 {
83 	/* restore clock configuration.  Writing CPUPLL last will
84 	 * stall a bit and stabilize other clocks (unless this is
85 	 * one of those Au1000 with a write-only PLL, where we dont
86 	 * have a valid value)
87 	 */
88 	alchemy_wrsys(sleep_sys_clocks[0], AU1000_SYS_FREQCTRL0);
89 	alchemy_wrsys(sleep_sys_clocks[1], AU1000_SYS_FREQCTRL1);
90 	alchemy_wrsys(sleep_sys_clocks[2], AU1000_SYS_CLKSRC);
91 	alchemy_wrsys(sleep_sys_clocks[4], AU1000_SYS_AUXPLL);
92 	if (!au1xxx_cpu_has_pll_wo())
93 		alchemy_wrsys(sleep_sys_clocks[3], AU1000_SYS_CPUPLL);
94 
95 	alchemy_wrsys(sleep_sys_pinfunc, AU1000_SYS_PINFUNC);
96 
97 	/* Restore the static memory controller configuration. */
98 	alchemy_wrsmem(sleep_static_memctlr[0][0], AU1000_MEM_STCFG0);
99 	alchemy_wrsmem(sleep_static_memctlr[0][1], AU1000_MEM_STTIME0);
100 	alchemy_wrsmem(sleep_static_memctlr[0][2], AU1000_MEM_STADDR0);
101 	alchemy_wrsmem(sleep_static_memctlr[1][0], AU1000_MEM_STCFG1);
102 	alchemy_wrsmem(sleep_static_memctlr[1][1], AU1000_MEM_STTIME1);
103 	alchemy_wrsmem(sleep_static_memctlr[1][2], AU1000_MEM_STADDR1);
104 	alchemy_wrsmem(sleep_static_memctlr[2][0], AU1000_MEM_STCFG2);
105 	alchemy_wrsmem(sleep_static_memctlr[2][1], AU1000_MEM_STTIME2);
106 	alchemy_wrsmem(sleep_static_memctlr[2][2], AU1000_MEM_STADDR2);
107 	alchemy_wrsmem(sleep_static_memctlr[3][0], AU1000_MEM_STCFG3);
108 	alchemy_wrsmem(sleep_static_memctlr[3][1], AU1000_MEM_STTIME3);
109 	alchemy_wrsmem(sleep_static_memctlr[3][2], AU1000_MEM_STADDR3);
110 }
111 
112 void au_sleep(void)
113 {
114 	save_core_regs();
115 
116 	switch (alchemy_get_cputype()) {
117 	case ALCHEMY_CPU_AU1000:
118 	case ALCHEMY_CPU_AU1500:
119 	case ALCHEMY_CPU_AU1100:
120 		alchemy_sleep_au1000();
121 		break;
122 	case ALCHEMY_CPU_AU1550:
123 	case ALCHEMY_CPU_AU1200:
124 		alchemy_sleep_au1550();
125 		break;
126 	case ALCHEMY_CPU_AU1300:
127 		alchemy_sleep_au1300();
128 		break;
129 	}
130 
131 	restore_core_regs();
132 }
133