xref: /openbmc/u-boot/drivers/gpio/bcm2835_gpio.c (revision e8f80a5a)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2012 Vikram Narayananan
4  * <vikram186@gmail.com>
5  */
6 
7 #include <common.h>
8 #include <dm.h>
9 #include <dm/pinctrl.h>
10 #include <errno.h>
11 #include <asm/gpio.h>
12 #include <asm/io.h>
13 #include <fdtdec.h>
14 
15 struct bcm2835_gpios {
16 	struct bcm2835_gpio_regs *reg;
17 	struct udevice *pinctrl;
18 };
19 
bcm2835_gpio_direction_input(struct udevice * dev,unsigned gpio)20 static int bcm2835_gpio_direction_input(struct udevice *dev, unsigned gpio)
21 {
22 	struct bcm2835_gpios *gpios = dev_get_priv(dev);
23 	unsigned val;
24 
25 	val = readl(&gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
26 	val &= ~(BCM2835_GPIO_FSEL_MASK << BCM2835_GPIO_FSEL_SHIFT(gpio));
27 	val |= (BCM2835_GPIO_INPUT << BCM2835_GPIO_FSEL_SHIFT(gpio));
28 	writel(val, &gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
29 
30 	return 0;
31 }
32 
bcm2835_gpio_direction_output(struct udevice * dev,unsigned int gpio,int value)33 static int bcm2835_gpio_direction_output(struct udevice *dev, unsigned int gpio,
34 					 int value)
35 {
36 	struct bcm2835_gpios *gpios = dev_get_priv(dev);
37 	unsigned val;
38 
39 	gpio_set_value(gpio, value);
40 
41 	val = readl(&gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
42 	val &= ~(BCM2835_GPIO_FSEL_MASK << BCM2835_GPIO_FSEL_SHIFT(gpio));
43 	val |= (BCM2835_GPIO_OUTPUT << BCM2835_GPIO_FSEL_SHIFT(gpio));
44 	writel(val, &gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
45 
46 	return 0;
47 }
48 
bcm2835_get_value(const struct bcm2835_gpios * gpios,unsigned gpio)49 static int bcm2835_get_value(const struct bcm2835_gpios *gpios, unsigned gpio)
50 {
51 	unsigned val;
52 
53 	val = readl(&gpios->reg->gplev[BCM2835_GPIO_COMMON_BANK(gpio)]);
54 
55 	return (val >> BCM2835_GPIO_COMMON_SHIFT(gpio)) & 0x1;
56 }
57 
bcm2835_gpio_get_value(struct udevice * dev,unsigned gpio)58 static int bcm2835_gpio_get_value(struct udevice *dev, unsigned gpio)
59 {
60 	const struct bcm2835_gpios *gpios = dev_get_priv(dev);
61 
62 	return bcm2835_get_value(gpios, gpio);
63 }
64 
bcm2835_gpio_set_value(struct udevice * dev,unsigned gpio,int value)65 static int bcm2835_gpio_set_value(struct udevice *dev, unsigned gpio,
66 				  int value)
67 {
68 	struct bcm2835_gpios *gpios = dev_get_priv(dev);
69 	u32 *output_reg = value ? gpios->reg->gpset : gpios->reg->gpclr;
70 
71 	writel(1 << BCM2835_GPIO_COMMON_SHIFT(gpio),
72 				&output_reg[BCM2835_GPIO_COMMON_BANK(gpio)]);
73 
74 	return 0;
75 }
76 
bcm2835_gpio_get_function(struct udevice * dev,unsigned offset)77 static int bcm2835_gpio_get_function(struct udevice *dev, unsigned offset)
78 {
79 	struct bcm2835_gpios *priv = dev_get_priv(dev);
80 	int funcid;
81 
82 	funcid = pinctrl_get_gpio_mux(priv->pinctrl, 0, offset);
83 
84 	switch (funcid) {
85 	case BCM2835_GPIO_OUTPUT:
86 		return GPIOF_OUTPUT;
87 	case BCM2835_GPIO_INPUT:
88 		return GPIOF_INPUT;
89 	default:
90 		return GPIOF_FUNC;
91 	}
92 }
93 
94 static const struct dm_gpio_ops gpio_bcm2835_ops = {
95 	.direction_input	= bcm2835_gpio_direction_input,
96 	.direction_output	= bcm2835_gpio_direction_output,
97 	.get_value		= bcm2835_gpio_get_value,
98 	.set_value		= bcm2835_gpio_set_value,
99 	.get_function		= bcm2835_gpio_get_function,
100 };
101 
bcm2835_gpio_probe(struct udevice * dev)102 static int bcm2835_gpio_probe(struct udevice *dev)
103 {
104 	struct bcm2835_gpios *gpios = dev_get_priv(dev);
105 	struct bcm2835_gpio_platdata *plat = dev_get_platdata(dev);
106 	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
107 
108 	uc_priv->bank_name = "GPIO";
109 	uc_priv->gpio_count = BCM2835_GPIO_COUNT;
110 	gpios->reg = (struct bcm2835_gpio_regs *)plat->base;
111 
112 	/* We know we're spawned by the pinctrl driver */
113 	gpios->pinctrl = dev->parent;
114 
115 	return 0;
116 }
117 
118 #if CONFIG_IS_ENABLED(OF_CONTROL)
bcm2835_gpio_ofdata_to_platdata(struct udevice * dev)119 static int bcm2835_gpio_ofdata_to_platdata(struct udevice *dev)
120 {
121 	struct bcm2835_gpio_platdata *plat = dev_get_platdata(dev);
122 	fdt_addr_t addr;
123 
124 	addr = devfdt_get_addr(dev);
125 	if (addr == FDT_ADDR_T_NONE)
126 		return -EINVAL;
127 
128 	plat->base = addr;
129 	return 0;
130 }
131 #endif
132 
133 U_BOOT_DRIVER(gpio_bcm2835) = {
134 	.name	= "gpio_bcm2835",
135 	.id	= UCLASS_GPIO,
136 	.ofdata_to_platdata = of_match_ptr(bcm2835_gpio_ofdata_to_platdata),
137 	.platdata_auto_alloc_size = sizeof(struct bcm2835_gpio_platdata),
138 	.ops	= &gpio_bcm2835_ops,
139 	.probe	= bcm2835_gpio_probe,
140 	.flags	= DM_FLAG_PRE_RELOC,
141 	.priv_auto_alloc_size = sizeof(struct bcm2835_gpios),
142 };
143