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
26static void __iomem *pinmux_base;
27
28/*
29 * Sets the DAVINCI MUX register based on the table
30 */
31int 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