1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Utility to set the DAVINCI MUX register from a table in mux.h
4  *
5  * Author: Vladimir Barinov, MontaVista Software, Inc. <source@mvista.com>
6  *
7  * Based on linux/arch/arm/plat-omap/mux.c:
8  * Copyright (C) 2003 - 2005 Nokia Corporation
9  *
10  * Written by Tony Lindgren
11  *
12  * 2007 (c) MontaVista Software, Inc.
13  *
14  * Copyright (C) 2008 Texas Instruments.
15  */
16 
17 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18 
19 #include <linux/io.h>
20 #include <linux/module.h>
21 #include <linux/spinlock.h>
22 
23 #include "mux.h"
24 #include "common.h"
25 
26 static void __iomem *pinmux_base;
27 
28 /*
29  * Sets the DAVINCI MUX register based on the table
30  */
davinci_cfg_reg(const unsigned long index)31 int davinci_cfg_reg(const unsigned long index)
32 {
33 	static DEFINE_SPINLOCK(mux_spin_lock);
34 	struct davinci_soc_info *soc_info = &davinci_soc_info;
35 	unsigned long flags;
36 	const struct mux_config *cfg;
37 	unsigned int reg_orig = 0, reg = 0;
38 	unsigned int mask, warn = 0;
39 
40 	if (WARN_ON(!soc_info->pinmux_pins))
41 		return -ENODEV;
42 
43 	if (!pinmux_base) {
44 		pinmux_base = ioremap(soc_info->pinmux_base, SZ_4K);
45 		if (WARN_ON(!pinmux_base))
46 			return -ENOMEM;
47 	}
48 
49 	if (index >= soc_info->pinmux_pins_num) {
50 		pr_err("Invalid pin mux index: %lu (%lu)\n",
51 		       index, soc_info->pinmux_pins_num);
52 		dump_stack();
53 		return -ENODEV;
54 	}
55 
56 	cfg = &soc_info->pinmux_pins[index];
57 
58 	if (cfg->name == NULL) {
59 		pr_err("No entry for the specified index\n");
60 		return -ENODEV;
61 	}
62 
63 	/* Update the mux register in question */
64 	if (cfg->mask) {
65 		unsigned	tmp1, tmp2;
66 
67 		spin_lock_irqsave(&mux_spin_lock, flags);
68 		reg_orig = __raw_readl(pinmux_base + cfg->mux_reg);
69 
70 		mask = (cfg->mask << cfg->mask_offset);
71 		tmp1 = reg_orig & mask;
72 		reg = reg_orig & ~mask;
73 
74 		tmp2 = (cfg->mode << cfg->mask_offset);
75 		reg |= tmp2;
76 
77 		if (tmp1 != tmp2)
78 			warn = 1;
79 
80 		__raw_writel(reg, pinmux_base + cfg->mux_reg);
81 		spin_unlock_irqrestore(&mux_spin_lock, flags);
82 	}
83 
84 	if (warn) {
85 #ifdef CONFIG_DAVINCI_MUX_WARNINGS
86 		pr_warn("initialized %s\n", cfg->name);
87 #endif
88 	}
89 
90 #ifdef CONFIG_DAVINCI_MUX_DEBUG
91 	if (cfg->debug || warn) {
92 		pr_warn("Setting register %s\n", cfg->name);
93 		pr_warn("   %s (0x%08x) = 0x%08x -> 0x%08x\n",
94 			cfg->mux_reg_name, cfg->mux_reg, reg_orig, reg);
95 	}
96 #endif
97 
98 	return 0;
99 }
100