kernel/arch/mips/alchemy/common/power.c

   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 <asm/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 }