xref: /openbmc/linux/arch/arm/mach-davinci/mux.c (revision 9cfc5c90)
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 
19 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
20 
21 #include <linux/io.h>
22 #include <linux/module.h>
23 #include <linux/spinlock.h>
24 
25 #include <mach/mux.h>
26 #include <mach/common.h>
27 
28 static void __iomem *pinmux_base;
29 
30 /*
31  * Sets the DAVINCI MUX register based on the table
32  */
33 int davinci_cfg_reg(const unsigned long index)
34 {
35 	static DEFINE_SPINLOCK(mux_spin_lock);
36 	struct davinci_soc_info *soc_info = &davinci_soc_info;
37 	unsigned long flags;
38 	const struct mux_config *cfg;
39 	unsigned int reg_orig = 0, reg = 0;
40 	unsigned int mask, warn = 0;
41 
42 	if (WARN_ON(!soc_info->pinmux_pins))
43 		return -ENODEV;
44 
45 	if (!pinmux_base) {
46 		pinmux_base = ioremap(soc_info->pinmux_base, SZ_4K);
47 		if (WARN_ON(!pinmux_base))
48 			return -ENOMEM;
49 	}
50 
51 	if (index >= soc_info->pinmux_pins_num) {
52 		pr_err("Invalid pin mux index: %lu (%lu)\n",
53 		       index, soc_info->pinmux_pins_num);
54 		dump_stack();
55 		return -ENODEV;
56 	}
57 
58 	cfg = &soc_info->pinmux_pins[index];
59 
60 	if (cfg->name == NULL) {
61 		pr_err("No entry for the specified index\n");
62 		return -ENODEV;
63 	}
64 
65 	/* Update the mux register in question */
66 	if (cfg->mask) {
67 		unsigned	tmp1, tmp2;
68 
69 		spin_lock_irqsave(&mux_spin_lock, flags);
70 		reg_orig = __raw_readl(pinmux_base + cfg->mux_reg);
71 
72 		mask = (cfg->mask << cfg->mask_offset);
73 		tmp1 = reg_orig & mask;
74 		reg = reg_orig & ~mask;
75 
76 		tmp2 = (cfg->mode << cfg->mask_offset);
77 		reg |= tmp2;
78 
79 		if (tmp1 != tmp2)
80 			warn = 1;
81 
82 		__raw_writel(reg, pinmux_base + cfg->mux_reg);
83 		spin_unlock_irqrestore(&mux_spin_lock, flags);
84 	}
85 
86 	if (warn) {
87 #ifdef CONFIG_DAVINCI_MUX_WARNINGS
88 		pr_warn("initialized %s\n", cfg->name);
89 #endif
90 	}
91 
92 #ifdef CONFIG_DAVINCI_MUX_DEBUG
93 	if (cfg->debug || warn) {
94 		pr_warn("Setting register %s\n", cfg->name);
95 		pr_warn("   %s (0x%08x) = 0x%08x -> 0x%08x\n",
96 			cfg->mux_reg_name, cfg->mux_reg, reg_orig, reg);
97 	}
98 #endif
99 
100 	return 0;
101 }
102 EXPORT_SYMBOL(davinci_cfg_reg);
103 
104 int davinci_cfg_reg_list(const short pins[])
105 {
106 	int i, error = -EINVAL;
107 
108 	if (pins)
109 		for (i = 0; pins[i] >= 0; i++) {
110 			error = davinci_cfg_reg(pins[i]);
111 			if (error)
112 				break;
113 		}
114 
115 	return error;
116 }
117