Linux Kernel  3.7.1
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pmc.c
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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 <mach/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 
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 }