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Sughosh Ganu48571ff2010-11-30 11:25:01 -05001/*
2 * DaVinci pinmux functions.
3 *
4 * Copyright (C) 2009 Nick Thompson, GE Fanuc Ltd, <nick.thompson@gefanuc.com>
5 * Copyright (C) 2007 Sergey Kubushyn <ksi@koi8.net>
6 * Copyright (C) 2008 Lyrtech <www.lyrtech.com>
7 * Copyright (C) 2004 Texas Instruments.
8 *
9 * See file CREDITS for list of people who contributed to this
10 * project.
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
16 *
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
21 *
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25 */
26
27#include <common.h>
28#include <asm/arch/hardware.h>
29#include <asm/io.h>
30#include <asm/arch/davinci_misc.h>
31
32/*
33 * Change the setting of a pin multiplexer field.
34 *
35 * Takes an array of pinmux settings similar to:
36 *
37 * struct pinmux_config uart_pins[] = {
38 * { &davinci_syscfg_regs->pinmux[8], 2, 7 },
39 * { &davinci_syscfg_regs->pinmux[9], 2, 0 }
40 * };
41 *
42 * Stepping through the array, each pinmux[n] register has the given value
43 * set in the pin mux field specified.
44 *
45 * The number of pins in the array must be passed (ARRAY_SIZE can provide
46 * this value conveniently).
47 *
48 * Returns 0 if all field numbers and values are in the correct range,
49 * else returns -1.
50 */
51int davinci_configure_pin_mux(const struct pinmux_config *pins,
52 const int n_pins)
53{
54 int i;
55
56 /* check for invalid pinmux values */
57 for (i = 0; i < n_pins; i++) {
58 if (pins[i].field >= PIN_MUX_NUM_FIELDS ||
59 (pins[i].value & ~PIN_MUX_FIELD_MASK) != 0)
60 return -1;
61 }
62
63 /* configure the pinmuxes */
64 for (i = 0; i < n_pins; i++) {
65 const int offset = pins[i].field * PIN_MUX_FIELD_SIZE;
66 const unsigned int value = pins[i].value << offset;
67 const unsigned int mask = PIN_MUX_FIELD_MASK << offset;
68 const dv_reg *mux = pins[i].mux;
69
70 writel(value | (readl(mux) & (~mask)), mux);
71 }
72
73 return 0;
74}
75
76/*
77 * Configure multiple pinmux resources.
78 *
79 * Takes an pinmux_resource array of pinmux_config and pin counts:
80 *
81 * const struct pinmux_resource pinmuxes[] = {
82 * PINMUX_ITEM(uart_pins),
83 * PINMUX_ITEM(i2c_pins),
84 * };
85 *
86 * The number of items in the array must be passed (ARRAY_SIZE can provide
87 * this value conveniently).
88 *
89 * Each item entry is configured in the defined order. If configuration
90 * of any item fails, -1 is returned and none of the following items are
91 * configured. On success, 0 is returned.
92 */
93int davinci_configure_pin_mux_items(const struct pinmux_resource *item,
94 const int n_items)
95{
96 int i;
97
98 for (i = 0; i < n_items; i++) {
99 if (davinci_configure_pin_mux(item[i].pins,
100 item[i].n_pins) != 0)
101 return -1;
102 }
103
104 return 0;
105}