xref: /linux/arch/arm/mach-davinci/mux.c (revision e190bfe56841551b1ad5abb42ebd0c4798cc8c01)
1 /*
2  * Utility to set the DAVINCI MUX register from a table in mux.h
3  *
4  * Author: Vladimir Barinov, MontaVista Software, Inc. <source@mvista.com>
5  *
6  * Based on linux/arch/arm/plat-omap/mux.c:
7  * Copyright (C) 2003 - 2005 Nokia Corporation
8  *
9  * Written by Tony Lindgren
10  *
11  * 2007 (c) MontaVista Software, Inc. This file is licensed under
12  * the terms of the GNU General Public License version 2. This program
13  * is licensed "as is" without any warranty of any kind, whether express
14  * or implied.
15  *
16  * Copyright (C) 2008 Texas Instruments.
17  */
18 #include <linux/io.h>
19 #include <linux/module.h>
20 #include <linux/spinlock.h>
21 
22 #include <mach/mux.h>
23 #include <mach/common.h>
24 
25 static void __iomem *pinmux_base;
26 
27 /*
28  * Sets the DAVINCI MUX register based on the table
29  */
30 int __init_or_module davinci_cfg_reg(const unsigned long index)
31 {
32 	static DEFINE_SPINLOCK(mux_spin_lock);
33 	struct davinci_soc_info *soc_info = &davinci_soc_info;
34 	unsigned long flags;
35 	const struct mux_config *cfg;
36 	unsigned int reg_orig = 0, reg = 0;
37 	unsigned int mask, warn = 0;
38 
39 	if (WARN_ON(!soc_info->pinmux_pins))
40 		return -ENODEV;
41 
42 	if (!pinmux_base) {
43 		pinmux_base = ioremap(soc_info->pinmux_base, SZ_4K);
44 		if (WARN_ON(!pinmux_base))
45 			return -ENOMEM;
46 	}
47 
48 	if (index >= soc_info->pinmux_pins_num) {
49 		printk(KERN_ERR "Invalid pin mux index: %lu (%lu)\n",
50 		       index, soc_info->pinmux_pins_num);
51 		dump_stack();
52 		return -ENODEV;
53 	}
54 
55 	cfg = &soc_info->pinmux_pins[index];
56 
57 	if (cfg->name == NULL) {
58 		printk(KERN_ERR "No entry for the specified index\n");
59 		return -ENODEV;
60 	}
61 
62 	/* Update the mux register in question */
63 	if (cfg->mask) {
64 		unsigned	tmp1, tmp2;
65 
66 		spin_lock_irqsave(&mux_spin_lock, flags);
67 		reg_orig = __raw_readl(pinmux_base + cfg->mux_reg);
68 
69 		mask = (cfg->mask << cfg->mask_offset);
70 		tmp1 = reg_orig & mask;
71 		reg = reg_orig & ~mask;
72 
73 		tmp2 = (cfg->mode << cfg->mask_offset);
74 		reg |= tmp2;
75 
76 		if (tmp1 != tmp2)
77 			warn = 1;
78 
79 		__raw_writel(reg, pinmux_base + cfg->mux_reg);
80 		spin_unlock_irqrestore(&mux_spin_lock, flags);
81 	}
82 
83 	if (warn) {
84 #ifdef CONFIG_DAVINCI_MUX_WARNINGS
85 		printk(KERN_WARNING "MUX: initialized %s\n", cfg->name);
86 #endif
87 	}
88 
89 #ifdef CONFIG_DAVINCI_MUX_DEBUG
90 	if (cfg->debug || warn) {
91 		printk(KERN_WARNING "MUX: Setting register %s\n", cfg->name);
92 		printk(KERN_WARNING "	   %s (0x%08x) = 0x%08x -> 0x%08x\n",
93 		       cfg->mux_reg_name, cfg->mux_reg, reg_orig, reg);
94 	}
95 #endif
96 
97 	return 0;
98 }
99 EXPORT_SYMBOL(davinci_cfg_reg);
100 
101 int __init_or_module davinci_cfg_reg_list(const short pins[])
102 {
103 	int i, error = -EINVAL;
104 
105 	if (pins)
106 		for (i = 0; pins[i] >= 0; i++) {
107 			error = davinci_cfg_reg(pins[i]);
108 			if (error)
109 				break;
110 		}
111 
112 	return error;
113 }
114