xref: /openbmc/u-boot/drivers/gpio/gpio-uniphier.c (revision baefb63a)
1 /*
2  * Copyright (C) 2016-2017 Socionext Inc.
3  *   Author: Masahiro Yamada <yamada.masahiro@socionext.com>
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6  */
7 
8 #include <common.h>
9 #include <dm.h>
10 #include <linux/bitops.h>
11 #include <linux/io.h>
12 #include <linux/sizes.h>
13 #include <linux/errno.h>
14 #include <asm/global_data.h>
15 #include <asm/gpio.h>
16 #include <dt-bindings/gpio/uniphier-gpio.h>
17 
18 #define UNIPHIER_GPIO_PORT_DATA		0x0	/* data */
19 #define UNIPHIER_GPIO_PORT_DIR		0x4	/* direction (1:in, 0:out) */
20 #define UNIPHIER_GPIO_IRQ_EN		0x90	/* irq enable */
21 
22 struct uniphier_gpio_priv {
23 	void __iomem *regs;
24 };
25 
26 static unsigned int uniphier_gpio_bank_to_reg(unsigned int bank)
27 {
28 	unsigned int reg;
29 
30 	reg = (bank + 1) * 8;
31 
32 	/*
33 	 * Unfortunately, the GPIO port registers are not contiguous because
34 	 * offset 0x90-0x9f is used for IRQ.  Add 0x10 when crossing the region.
35 	 */
36 	if (reg >= UNIPHIER_GPIO_IRQ_EN)
37 		reg += 0x10;
38 
39 	return reg;
40 }
41 
42 static void uniphier_gpio_get_bank_and_mask(unsigned int offset,
43 					    unsigned int *bank, u32 *mask)
44 {
45 	*bank = offset / UNIPHIER_GPIO_LINES_PER_BANK;
46 	*mask = BIT(offset % UNIPHIER_GPIO_LINES_PER_BANK);
47 }
48 
49 static void uniphier_gpio_reg_update(struct uniphier_gpio_priv *priv,
50 				     unsigned int reg, u32 mask, u32 val)
51 {
52 	u32 tmp;
53 
54 	tmp = readl(priv->regs + reg);
55 	tmp &= ~mask;
56 	tmp |= mask & val;
57 	writel(tmp, priv->regs + reg);
58 }
59 
60 static void uniphier_gpio_bank_write(struct udevice *dev, unsigned int bank,
61 				     unsigned int reg, u32 mask, u32 val)
62 {
63 	struct uniphier_gpio_priv *priv = dev_get_priv(dev);
64 
65 	if (!mask)
66 		return;
67 
68 	uniphier_gpio_reg_update(priv, uniphier_gpio_bank_to_reg(bank) + reg,
69 				 mask, val);
70 }
71 
72 static void uniphier_gpio_offset_write(struct udevice *dev, unsigned int offset,
73 				       unsigned int reg, int val)
74 {
75 	unsigned int bank;
76 	u32 mask;
77 
78 	uniphier_gpio_get_bank_and_mask(offset, &bank, &mask);
79 
80 	uniphier_gpio_bank_write(dev, bank, reg, mask, val ? mask : 0);
81 }
82 
83 static int uniphier_gpio_offset_read(struct udevice *dev,
84 				     unsigned int offset, unsigned int reg)
85 {
86 	struct uniphier_gpio_priv *priv = dev_get_priv(dev);
87 	unsigned int bank, reg_offset;
88 	u32 mask;
89 
90 	uniphier_gpio_get_bank_and_mask(offset, &bank, &mask);
91 	reg_offset = uniphier_gpio_bank_to_reg(bank) + reg;
92 
93 	return !!(readl(priv->regs + reg_offset) & mask);
94 }
95 
96 static int uniphier_gpio_get_function(struct udevice *dev, unsigned int offset)
97 {
98 	return uniphier_gpio_offset_read(dev, offset, UNIPHIER_GPIO_PORT_DIR) ?
99 						GPIOF_INPUT : GPIOF_OUTPUT;
100 }
101 
102 static int uniphier_gpio_direction_input(struct udevice *dev,
103 					 unsigned int offset)
104 {
105 	uniphier_gpio_offset_write(dev, offset, UNIPHIER_GPIO_PORT_DIR, 1);
106 
107 	return 0;
108 }
109 
110 static int uniphier_gpio_direction_output(struct udevice *dev,
111 					  unsigned int offset, int value)
112 {
113 	uniphier_gpio_offset_write(dev, offset, UNIPHIER_GPIO_PORT_DATA, value);
114 	uniphier_gpio_offset_write(dev, offset, UNIPHIER_GPIO_PORT_DIR, 0);
115 
116 	return 0;
117 }
118 
119 static int uniphier_gpio_get_value(struct udevice *dev, unsigned int offset)
120 {
121 	return uniphier_gpio_offset_read(dev, offset, UNIPHIER_GPIO_PORT_DATA);
122 }
123 
124 static int uniphier_gpio_set_value(struct udevice *dev,
125 				   unsigned int offset, int value)
126 {
127 	uniphier_gpio_offset_write(dev, offset, UNIPHIER_GPIO_PORT_DATA, value);
128 
129 	return 0;
130 }
131 
132 static const struct dm_gpio_ops uniphier_gpio_ops = {
133 	.direction_input	= uniphier_gpio_direction_input,
134 	.direction_output	= uniphier_gpio_direction_output,
135 	.get_value		= uniphier_gpio_get_value,
136 	.set_value		= uniphier_gpio_set_value,
137 	.get_function		= uniphier_gpio_get_function,
138 };
139 
140 static int uniphier_gpio_probe(struct udevice *dev)
141 {
142 	struct uniphier_gpio_priv *priv = dev_get_priv(dev);
143 	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
144 	fdt_addr_t addr;
145 
146 	addr = devfdt_get_addr(dev);
147 	if (addr == FDT_ADDR_T_NONE)
148 		return -EINVAL;
149 
150 	priv->regs = devm_ioremap(dev, addr, SZ_512);
151 	if (!priv->regs)
152 		return -ENOMEM;
153 
154 	uc_priv->gpio_count = fdtdec_get_uint(gd->fdt_blob, dev_of_offset(dev),
155 					      "ngpios", 0);
156 
157 	return 0;
158 }
159 
160 static const struct udevice_id uniphier_gpio_match[] = {
161 	{ .compatible = "socionext,uniphier-gpio" },
162 	{ /* sentinel */ }
163 };
164 
165 U_BOOT_DRIVER(uniphier_gpio) = {
166 	.name	= "uniphier-gpio",
167 	.id	= UCLASS_GPIO,
168 	.of_match = uniphier_gpio_match,
169 	.probe	= uniphier_gpio_probe,
170 	.priv_auto_alloc_size = sizeof(struct uniphier_gpio_priv),
171 	.ops	= &uniphier_gpio_ops,
172 };
173