xref: /openbmc/u-boot/arch/arm/mach-davinci/pinmux.c (revision dd1033e4)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * DaVinci pinmux functions.
4  *
5  * Copyright (C) 2009 Nick Thompson, GE Fanuc Ltd, <nick.thompson@gefanuc.com>
6  * Copyright (C) 2007 Sergey Kubushyn <ksi@koi8.net>
7  * Copyright (C) 2008 Lyrtech <www.lyrtech.com>
8  * Copyright (C) 2004 Texas Instruments.
9  */
10 
11 #include <common.h>
12 #include <asm/arch/hardware.h>
13 #include <asm/io.h>
14 #include <asm/arch/davinci_misc.h>
15 
16 /*
17  * Change the setting of a pin multiplexer field.
18  *
19  * Takes an array of pinmux settings similar to:
20  *
21  * struct pinmux_config uart_pins[] = {
22  *	{ &davinci_syscfg_regs->pinmux[8], 2, 7 },
23  *	{ &davinci_syscfg_regs->pinmux[9], 2, 0 }
24  * };
25  *
26  * Stepping through the array, each pinmux[n] register has the given value
27  * set in the pin mux field specified.
28  *
29  * The number of pins in the array must be passed (ARRAY_SIZE can provide
30  * this value conveniently).
31  *
32  * Returns 0 if all field numbers and values are in the correct range,
33  * else returns -1.
34  */
35 int davinci_configure_pin_mux(const struct pinmux_config *pins,
36 			      const int n_pins)
37 {
38 	int i;
39 
40 	/* check for invalid pinmux values */
41 	for (i = 0; i < n_pins; i++) {
42 		if (pins[i].field >= PIN_MUX_NUM_FIELDS ||
43 		    (pins[i].value & ~PIN_MUX_FIELD_MASK) != 0)
44 			return -1;
45 	}
46 
47 	/* configure the pinmuxes */
48 	for (i = 0; i < n_pins; i++) {
49 		const int offset = pins[i].field * PIN_MUX_FIELD_SIZE;
50 		const unsigned int value = pins[i].value << offset;
51 		const unsigned int mask = PIN_MUX_FIELD_MASK << offset;
52 		const dv_reg *mux = pins[i].mux;
53 
54 		writel(value | (readl(mux) & (~mask)), mux);
55 	}
56 
57 	return 0;
58 }
59 
60 /*
61  * Configure multiple pinmux resources.
62  *
63  * Takes an pinmux_resource array of pinmux_config and pin counts:
64  *
65  * const struct pinmux_resource pinmuxes[] = {
66  *	PINMUX_ITEM(uart_pins),
67  *	PINMUX_ITEM(i2c_pins),
68  * };
69  *
70  * The number of items in the array must be passed (ARRAY_SIZE can provide
71  * this value conveniently).
72  *
73  * Each item entry is configured in the defined order. If configuration
74  * of any item fails, -1 is returned and none of the following items are
75  * configured. On success, 0 is returned.
76  */
77 int davinci_configure_pin_mux_items(const struct pinmux_resource *item,
78 				    const int n_items)
79 {
80 	int i;
81 
82 	for (i = 0; i < n_items; i++) {
83 		if (davinci_configure_pin_mux(item[i].pins,
84 					      item[i].n_pins) != 0)
85 			return -1;
86 	}
87 
88 	return 0;
89 }
90