xref: /openbmc/u-boot/arch/arm/mach-davinci/pinmux.c (revision 1d2c0506)
1 /*
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  * SPDX-License-Identifier:	GPL-2.0+
10  */
11 
12 #include <common.h>
13 #include <asm/arch/hardware.h>
14 #include <asm/io.h>
15 #include <asm/arch/davinci_misc.h>
16 
17 /*
18  * Change the setting of a pin multiplexer field.
19  *
20  * Takes an array of pinmux settings similar to:
21  *
22  * struct pinmux_config uart_pins[] = {
23  *	{ &davinci_syscfg_regs->pinmux[8], 2, 7 },
24  *	{ &davinci_syscfg_regs->pinmux[9], 2, 0 }
25  * };
26  *
27  * Stepping through the array, each pinmux[n] register has the given value
28  * set in the pin mux field specified.
29  *
30  * The number of pins in the array must be passed (ARRAY_SIZE can provide
31  * this value conveniently).
32  *
33  * Returns 0 if all field numbers and values are in the correct range,
34  * else returns -1.
35  */
36 int davinci_configure_pin_mux(const struct pinmux_config *pins,
37 			      const int n_pins)
38 {
39 	int i;
40 
41 	/* check for invalid pinmux values */
42 	for (i = 0; i < n_pins; i++) {
43 		if (pins[i].field >= PIN_MUX_NUM_FIELDS ||
44 		    (pins[i].value & ~PIN_MUX_FIELD_MASK) != 0)
45 			return -1;
46 	}
47 
48 	/* configure the pinmuxes */
49 	for (i = 0; i < n_pins; i++) {
50 		const int offset = pins[i].field * PIN_MUX_FIELD_SIZE;
51 		const unsigned int value = pins[i].value << offset;
52 		const unsigned int mask = PIN_MUX_FIELD_MASK << offset;
53 		const dv_reg *mux = pins[i].mux;
54 
55 		writel(value | (readl(mux) & (~mask)), mux);
56 	}
57 
58 	return 0;
59 }
60 
61 /*
62  * Configure multiple pinmux resources.
63  *
64  * Takes an pinmux_resource array of pinmux_config and pin counts:
65  *
66  * const struct pinmux_resource pinmuxes[] = {
67  *	PINMUX_ITEM(uart_pins),
68  *	PINMUX_ITEM(i2c_pins),
69  * };
70  *
71  * The number of items in the array must be passed (ARRAY_SIZE can provide
72  * this value conveniently).
73  *
74  * Each item entry is configured in the defined order. If configuration
75  * of any item fails, -1 is returned and none of the following items are
76  * configured. On success, 0 is returned.
77  */
78 int davinci_configure_pin_mux_items(const struct pinmux_resource *item,
79 				    const int n_items)
80 {
81 	int i;
82 
83 	for (i = 0; i < n_items; i++) {
84 		if (davinci_configure_pin_mux(item[i].pins,
85 					      item[i].n_pins) != 0)
86 			return -1;
87 	}
88 
89 	return 0;
90 }
91