xref: /openbmc/u-boot/drivers/gpio/pic32_gpio.c (revision e246b728)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (c) 2015 Microchip Technology Inc
4  * Purna Chandra Mandal <purna.mandal@microchip.com>
5  */
6 
7 #include <common.h>
8 #include <dm.h>
9 #include <errno.h>
10 #include <malloc.h>
11 #include <asm/io.h>
12 #include <asm/gpio.h>
13 #include <linux/compat.h>
14 #include <mach/pic32.h>
15 
16 DECLARE_GLOBAL_DATA_PTR;
17 
18 /* Peripheral Pin Control */
19 struct pic32_reg_port {
20 	struct pic32_reg_atomic ansel;
21 	struct pic32_reg_atomic tris;
22 	struct pic32_reg_atomic port;
23 	struct pic32_reg_atomic lat;
24 	struct pic32_reg_atomic open_drain;
25 	struct pic32_reg_atomic cnpu;
26 	struct pic32_reg_atomic cnpd;
27 	struct pic32_reg_atomic cncon;
28 };
29 
30 enum {
31 	MICROCHIP_GPIO_DIR_OUT,
32 	MICROCHIP_GPIO_DIR_IN,
33 	MICROCHIP_GPIOS_PER_BANK = 16,
34 };
35 
36 struct pic32_gpio_priv {
37 	struct pic32_reg_port *regs;
38 	char name[2];
39 };
40 
41 static int pic32_gpio_get_value(struct udevice *dev, unsigned offset)
42 {
43 	struct pic32_gpio_priv *priv = dev_get_priv(dev);
44 
45 	return !!(readl(&priv->regs->port.raw) & BIT(offset));
46 }
47 
48 static int pic32_gpio_set_value(struct udevice *dev, unsigned offset,
49 				int value)
50 {
51 	struct pic32_gpio_priv *priv = dev_get_priv(dev);
52 	int mask = BIT(offset);
53 
54 	if (value)
55 		writel(mask, &priv->regs->port.set);
56 	else
57 		writel(mask, &priv->regs->port.clr);
58 
59 	return 0;
60 }
61 
62 static int pic32_gpio_direction(struct udevice *dev, unsigned offset)
63 {
64 	struct pic32_gpio_priv *priv = dev_get_priv(dev);
65 
66 	/* pin in analog mode ? */
67 	if (readl(&priv->regs->ansel.raw) & BIT(offset))
68 		return -EPERM;
69 
70 	if (readl(&priv->regs->tris.raw) & BIT(offset))
71 		return MICROCHIP_GPIO_DIR_IN;
72 	else
73 		return MICROCHIP_GPIO_DIR_OUT;
74 }
75 
76 static int pic32_gpio_direction_input(struct udevice *dev, unsigned offset)
77 {
78 	struct pic32_gpio_priv *priv = dev_get_priv(dev);
79 	int mask = BIT(offset);
80 
81 	writel(mask, &priv->regs->ansel.clr);
82 	writel(mask, &priv->regs->tris.set);
83 
84 	return 0;
85 }
86 
87 static int pic32_gpio_direction_output(struct udevice *dev,
88 				       unsigned offset, int value)
89 {
90 	struct pic32_gpio_priv *priv = dev_get_priv(dev);
91 	int mask = BIT(offset);
92 
93 	writel(mask, &priv->regs->ansel.clr);
94 	writel(mask, &priv->regs->tris.clr);
95 
96 	pic32_gpio_set_value(dev, offset, value);
97 	return 0;
98 }
99 
100 static int pic32_gpio_get_function(struct udevice *dev, unsigned offset)
101 {
102 	int ret = GPIOF_UNUSED;
103 
104 	switch (pic32_gpio_direction(dev, offset)) {
105 	case MICROCHIP_GPIO_DIR_OUT:
106 		ret = GPIOF_OUTPUT;
107 		break;
108 	case MICROCHIP_GPIO_DIR_IN:
109 		ret = GPIOF_INPUT;
110 		break;
111 	default:
112 		ret = GPIOF_UNUSED;
113 		break;
114 	}
115 	return ret;
116 }
117 
118 static const struct dm_gpio_ops gpio_pic32_ops = {
119 	.direction_input	= pic32_gpio_direction_input,
120 	.direction_output	= pic32_gpio_direction_output,
121 	.get_value		= pic32_gpio_get_value,
122 	.set_value		= pic32_gpio_set_value,
123 	.get_function		= pic32_gpio_get_function,
124 };
125 
126 static int pic32_gpio_probe(struct udevice *dev)
127 {
128 	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
129 	struct pic32_gpio_priv *priv = dev_get_priv(dev);
130 	fdt_addr_t addr;
131 	fdt_size_t size;
132 	char *end;
133 	int bank;
134 
135 	addr = fdtdec_get_addr_size(gd->fdt_blob, dev_of_offset(dev), "reg",
136 				    &size);
137 	if (addr == FDT_ADDR_T_NONE)
138 		return -EINVAL;
139 
140 	priv->regs = ioremap(addr, size);
141 
142 	uc_priv->gpio_count = MICROCHIP_GPIOS_PER_BANK;
143 	/* extract bank name */
144 	end = strrchr(dev->name, '@');
145 	bank = trailing_strtoln(dev->name, end);
146 	priv->name[0] = 'A' + bank;
147 	uc_priv->bank_name = priv->name;
148 
149 	return 0;
150 }
151 
152 static const struct udevice_id pic32_gpio_ids[] = {
153 	{ .compatible = "microchip,pic32mzda-gpio" },
154 	{ }
155 };
156 
157 U_BOOT_DRIVER(gpio_pic32) = {
158 	.name		= "gpio_pic32",
159 	.id		= UCLASS_GPIO,
160 	.of_match	= pic32_gpio_ids,
161 	.ops		= &gpio_pic32_ops,
162 	.probe		= pic32_gpio_probe,
163 	.priv_auto_alloc_size	= sizeof(struct pic32_gpio_priv),
164 };
165