arch/arm/mach-tegra/flowctrl.c

   1 /*
   2  * arch/arm/mach-tegra/flowctrl.c
   3  *
   4  * functions and macros to control the flowcontroller
   5  *
   6  * Copyright (c) 2010-2012, NVIDIA Corporation. All rights reserved.
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms and conditions of the GNU General Public License,
  10  * version 2, as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful, but WITHOUT
  13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  15  * more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include <linux/init.h>
  22 #include <linux/kernel.h>
  23 #include <linux/io.h>
  24 #include <linux/cpumask.h>
  25
  26 #include "flowctrl.h"
  27 #include "iomap.h"
  28 #include "fuse.h"
  29
  30 static u8 flowctrl_offset_halt_cpu[] = {
  31         FLOW_CTRL_HALT_CPU0_EVENTS,
  32         FLOW_CTRL_HALT_CPU1_EVENTS,
  33         FLOW_CTRL_HALT_CPU1_EVENTS + 8,
  34         FLOW_CTRL_HALT_CPU1_EVENTS + 16,
  35 };
  36
  37 static u8 flowctrl_offset_cpu_csr[] = {
  38         FLOW_CTRL_CPU0_CSR,
  39         FLOW_CTRL_CPU1_CSR,
  40         FLOW_CTRL_CPU1_CSR + 8,
  41         FLOW_CTRL_CPU1_CSR + 16,
  42 };
  43
  44 static void flowctrl_update(u8 offset, u32 value)
  45 {
  46         void __iomem *addr = IO_ADDRESS(TEGRA_FLOW_CTRL_BASE) + offset;
  47
  48         writel(value, addr);
  49
  50         /* ensure the update has reached the flow controller */
  51         wmb();
  52         readl_relaxed(addr);
  53 }
  54
  55 u32 flowctrl_read_cpu_csr(unsigned int cpuid)
  56 {
  57         u8 offset = flowctrl_offset_cpu_csr[cpuid];
  58         void __iomem *addr = IO_ADDRESS(TEGRA_FLOW_CTRL_BASE) + offset;
  59
  60         return readl(addr);
  61 }
  62
  63 void flowctrl_write_cpu_csr(unsigned int cpuid, u32 value)
  64 {
  65         return flowctrl_update(flowctrl_offset_cpu_csr[cpuid], value);
  66 }
  67
  68 void flowctrl_write_cpu_halt(unsigned int cpuid, u32 value)
  69 {
  70         return flowctrl_update(flowctrl_offset_halt_cpu[cpuid], value);
  71 }
  72
  73 void flowctrl_cpu_suspend_enter(unsigned int cpuid)
  74 {
  75         unsigned int reg;
  76         int i;
  77
  78         reg = flowctrl_read_cpu_csr(cpuid);
  79         switch (tegra_chip_id) {
  80         case TEGRA20:
  81                 /* clear wfe bitmap */
  82                 reg &= ~TEGRA20_FLOW_CTRL_CSR_WFE_BITMAP;
  83                 /* clear wfi bitmap */
  84                 reg &= ~TEGRA20_FLOW_CTRL_CSR_WFI_BITMAP;
  85                 /* pwr gating on wfe */
  86                 reg |= TEGRA20_FLOW_CTRL_CSR_WFE_CPU0 << cpuid;
  87                 break;
  88         case TEGRA30:
  89                 /* clear wfe bitmap */
  90                 reg &= ~TEGRA30_FLOW_CTRL_CSR_WFE_BITMAP;
  91                 /* clear wfi bitmap */
  92                 reg &= ~TEGRA30_FLOW_CTRL_CSR_WFI_BITMAP;
  93                 /* pwr gating on wfi */
  94                 reg |= TEGRA30_FLOW_CTRL_CSR_WFI_CPU0 << cpuid;
  95                 break;
  96         }
  97         reg |= FLOW_CTRL_CSR_INTR_FLAG;                 /* clear intr flag */
  98         reg |= FLOW_CTRL_CSR_EVENT_FLAG;                /* clear event flag */
  99         reg |= FLOW_CTRL_CSR_ENABLE;                    /* pwr gating */
 100         flowctrl_write_cpu_csr(cpuid, reg);
 101
 102         for (i = 0; i < num_possible_cpus(); i++) {
 103                 if (i == cpuid)
 104                         continue;
 105                 reg = flowctrl_read_cpu_csr(i);
 106                 reg |= FLOW_CTRL_CSR_EVENT_FLAG;
 107                 reg |= FLOW_CTRL_CSR_INTR_FLAG;
 108                 flowctrl_write_cpu_csr(i, reg);
 109         }
 110 }
 111
 112 void flowctrl_cpu_suspend_exit(unsigned int cpuid)
 113 {
 114         unsigned int reg;
 115
 116         /* Disable powergating via flow controller for CPU0 */
 117         reg = flowctrl_read_cpu_csr(cpuid);
 118         switch (tegra_chip_id) {
 119         case TEGRA20:
 120                 /* clear wfe bitmap */
 121                 reg &= ~TEGRA20_FLOW_CTRL_CSR_WFE_BITMAP;
 122                 /* clear wfi bitmap */
 123                 reg &= ~TEGRA20_FLOW_CTRL_CSR_WFI_BITMAP;
 124                 break;
 125         case TEGRA30:
 126                 /* clear wfe bitmap */
 127                 reg &= ~TEGRA30_FLOW_CTRL_CSR_WFE_BITMAP;
 128                 /* clear wfi bitmap */
 129                 reg &= ~TEGRA30_FLOW_CTRL_CSR_WFI_BITMAP;
 130                 break;
 131         }
 132         reg &= ~FLOW_CTRL_CSR_ENABLE;                   /* clear enable */
 133         reg |= FLOW_CTRL_CSR_INTR_FLAG;                 /* clear intr */
 134         reg |= FLOW_CTRL_CSR_EVENT_FLAG;                /* clear event */
 135         flowctrl_write_cpu_csr(cpuid, reg);
 136 }