xref: /openbmc/u-boot/drivers/gpio/pic32_gpio.c (revision baefb63a)
1 /*
2  * Copyright (c) 2015 Microchip Technology Inc
3  * Purna Chandra Mandal <purna.mandal@microchip.com>
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6  */
7 
8 #include <common.h>
9 #include <dm.h>
10 #include <errno.h>
11 #include <malloc.h>
12 #include <asm/io.h>
13 #include <asm/gpio.h>
14 #include <linux/compat.h>
15 #include <mach/pic32.h>
16 
17 DECLARE_GLOBAL_DATA_PTR;
18 
19 /* Peripheral Pin Control */
20 struct pic32_reg_port {
21 	struct pic32_reg_atomic ansel;
22 	struct pic32_reg_atomic tris;
23 	struct pic32_reg_atomic port;
24 	struct pic32_reg_atomic lat;
25 	struct pic32_reg_atomic open_drain;
26 	struct pic32_reg_atomic cnpu;
27 	struct pic32_reg_atomic cnpd;
28 	struct pic32_reg_atomic cncon;
29 };
30 
31 enum {
32 	MICROCHIP_GPIO_DIR_OUT,
33 	MICROCHIP_GPIO_DIR_IN,
34 	MICROCHIP_GPIOS_PER_BANK = 16,
35 };
36 
37 struct pic32_gpio_priv {
38 	struct pic32_reg_port *regs;
39 	char name[2];
40 };
41 
42 static int pic32_gpio_get_value(struct udevice *dev, unsigned offset)
43 {
44 	struct pic32_gpio_priv *priv = dev_get_priv(dev);
45 
46 	return !!(readl(&priv->regs->port.raw) & BIT(offset));
47 }
48 
49 static int pic32_gpio_set_value(struct udevice *dev, unsigned offset,
50 				int value)
51 {
52 	struct pic32_gpio_priv *priv = dev_get_priv(dev);
53 	int mask = BIT(offset);
54 
55 	if (value)
56 		writel(mask, &priv->regs->port.set);
57 	else
58 		writel(mask, &priv->regs->port.clr);
59 
60 	return 0;
61 }
62 
63 static int pic32_gpio_direction(struct udevice *dev, unsigned offset)
64 {
65 	struct pic32_gpio_priv *priv = dev_get_priv(dev);
66 
67 	/* pin in analog mode ? */
68 	if (readl(&priv->regs->ansel.raw) & BIT(offset))
69 		return -EPERM;
70 
71 	if (readl(&priv->regs->tris.raw) & BIT(offset))
72 		return MICROCHIP_GPIO_DIR_IN;
73 	else
74 		return MICROCHIP_GPIO_DIR_OUT;
75 }
76 
77 static int pic32_gpio_direction_input(struct udevice *dev, unsigned offset)
78 {
79 	struct pic32_gpio_priv *priv = dev_get_priv(dev);
80 	int mask = BIT(offset);
81 
82 	writel(mask, &priv->regs->ansel.clr);
83 	writel(mask, &priv->regs->tris.set);
84 
85 	return 0;
86 }
87 
88 static int pic32_gpio_direction_output(struct udevice *dev,
89 				       unsigned offset, int value)
90 {
91 	struct pic32_gpio_priv *priv = dev_get_priv(dev);
92 	int mask = BIT(offset);
93 
94 	writel(mask, &priv->regs->ansel.clr);
95 	writel(mask, &priv->regs->tris.clr);
96 
97 	pic32_gpio_set_value(dev, offset, value);
98 	return 0;
99 }
100 
101 static int pic32_gpio_get_function(struct udevice *dev, unsigned offset)
102 {
103 	int ret = GPIOF_UNUSED;
104 
105 	switch (pic32_gpio_direction(dev, offset)) {
106 	case MICROCHIP_GPIO_DIR_OUT:
107 		ret = GPIOF_OUTPUT;
108 		break;
109 	case MICROCHIP_GPIO_DIR_IN:
110 		ret = GPIOF_INPUT;
111 		break;
112 	default:
113 		ret = GPIOF_UNUSED;
114 		break;
115 	}
116 	return ret;
117 }
118 
119 static const struct dm_gpio_ops gpio_pic32_ops = {
120 	.direction_input	= pic32_gpio_direction_input,
121 	.direction_output	= pic32_gpio_direction_output,
122 	.get_value		= pic32_gpio_get_value,
123 	.set_value		= pic32_gpio_set_value,
124 	.get_function		= pic32_gpio_get_function,
125 };
126 
127 static int pic32_gpio_probe(struct udevice *dev)
128 {
129 	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
130 	struct pic32_gpio_priv *priv = dev_get_priv(dev);
131 	fdt_addr_t addr;
132 	fdt_size_t size;
133 	char *end;
134 	int bank;
135 
136 	addr = fdtdec_get_addr_size(gd->fdt_blob, dev_of_offset(dev), "reg",
137 				    &size);
138 	if (addr == FDT_ADDR_T_NONE)
139 		return -EINVAL;
140 
141 	priv->regs = ioremap(addr, size);
142 
143 	uc_priv->gpio_count = MICROCHIP_GPIOS_PER_BANK;
144 	/* extract bank name */
145 	end = strrchr(dev->name, '@');
146 	bank = trailing_strtoln(dev->name, end);
147 	priv->name[0] = 'A' + bank;
148 	uc_priv->bank_name = priv->name;
149 
150 	return 0;
151 }
152 
153 static const struct udevice_id pic32_gpio_ids[] = {
154 	{ .compatible = "microchip,pic32mzda-gpio" },
155 	{ }
156 };
157 
158 U_BOOT_DRIVER(gpio_pic32) = {
159 	.name		= "gpio_pic32",
160 	.id		= UCLASS_GPIO,
161 	.of_match	= pic32_gpio_ids,
162 	.ops		= &gpio_pic32_ops,
163 	.probe		= pic32_gpio_probe,
164 	.priv_auto_alloc_size	= sizeof(struct pic32_gpio_priv),
165 };
166