arch/arm/mach-tegra/pmc.c

   1 /*
   2  * Copyright (C) 2012 NVIDIA CORPORATION. All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms and conditions of the GNU General Public License,
   6  * version 2, as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  15  *
  16  */
  17
  18 #include <linux/kernel.h>
  19 #include <linux/io.h>
  20 #include <linux/of.h>
  21
  22 #include "iomap.h"
  23
  24 #define PMC_CTRL                0x0
  25 #define PMC_CTRL_INTR_LOW       (1 << 17)
  26
  27 static inline u32 tegra_pmc_readl(u32 reg)
  28 {
  29         return readl(IO_ADDRESS(TEGRA_PMC_BASE + reg));
  30 }
  31
  32 static inline void tegra_pmc_writel(u32 val, u32 reg)
  33 {
  34         writel(val, IO_ADDRESS(TEGRA_PMC_BASE + reg));
  35 }
  36
  37 #ifdef CONFIG_OF
  38 static const struct of_device_id matches[] __initconst = {
  39         { .compatible = "nvidia,tegra20-pmc" },
  40         { }
  41 };
  42 #endif
  43
  44 void __init tegra_pmc_init(void)
  45 {
  46         /*
  47          * For now, Harmony is the only board that uses the PMC, and it wants
  48          * the signal inverted. Seaboard would too if it used the PMC.
  49          * Hopefully by the time other boards want to use the PMC, everything
  50          * will be device-tree, or they also want it inverted.
  51          */
  52         bool invert_interrupt = true;
  53         u32 val;
  54
  55 #ifdef CONFIG_OF
  56         if (of_have_populated_dt()) {
  57                 struct device_node *np;
  58
  59                 invert_interrupt = false;
  60
  61                 np = of_find_matching_node(NULL, matches);
  62                 if (np) {
  63                         if (of_find_property(np, "nvidia,invert-interrupt",
  64                                                 NULL))
  65                                 invert_interrupt = true;
  66                 }
  67         }
  68 #endif
  69
  70         val = tegra_pmc_readl(PMC_CTRL);
  71         if (invert_interrupt)
  72                 val |= PMC_CTRL_INTR_LOW;
  73         else
  74                 val &= ~PMC_CTRL_INTR_LOW;
  75         tegra_pmc_writel(val, PMC_CTRL);
  76 }