1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2018 Alexander Graf <agraf@suse.de>
4  *
5  * Based on drivers/pinctrl/mvebu/pinctrl-mvebu.c and
6  *          drivers/gpio/bcm2835_gpio.c
7  *
8  * This driver gets instantiated by the GPIO driver, because both devices
9  * share the same device node.
10  * https://spdx.org/licenses
11  */
12 
13 #include <common.h>
14 #include <config.h>
15 #include <errno.h>
16 #include <dm.h>
17 #include <dm/pinctrl.h>
18 #include <dm/root.h>
19 #include <dm/device-internal.h>
20 #include <dm/lists.h>
21 #include <asm/system.h>
22 #include <asm/io.h>
23 #include <asm/gpio.h>
24 
25 struct bcm283x_pinctrl_priv {
26 	u32 *base_reg;
27 };
28 
29 #define MAX_PINS_PER_BANK 16
30 
bcm2835_gpio_set_func_id(struct udevice * dev,unsigned int gpio,int func)31 static void bcm2835_gpio_set_func_id(struct udevice *dev, unsigned int gpio,
32 				     int func)
33 {
34 	struct bcm283x_pinctrl_priv *priv = dev_get_priv(dev);
35 	int reg_offset;
36 	int field_offset;
37 
38 	reg_offset = BCM2835_GPIO_FSEL_BANK(gpio);
39 	field_offset = BCM2835_GPIO_FSEL_SHIFT(gpio);
40 
41 	clrsetbits_le32(&priv->base_reg[reg_offset],
42 			BCM2835_GPIO_FSEL_MASK << field_offset,
43 			(func & BCM2835_GPIO_FSEL_MASK) << field_offset);
44 }
45 
bcm2835_gpio_get_func_id(struct udevice * dev,unsigned int gpio)46 static int bcm2835_gpio_get_func_id(struct udevice *dev, unsigned int gpio)
47 {
48 	struct bcm283x_pinctrl_priv *priv = dev_get_priv(dev);
49 	u32 val;
50 
51 	val = readl(&priv->base_reg[BCM2835_GPIO_FSEL_BANK(gpio)]);
52 
53 	return (val >> BCM2835_GPIO_FSEL_SHIFT(gpio) & BCM2835_GPIO_FSEL_MASK);
54 }
55 
56 /*
57  * bcm283x_pinctrl_set_state: configure pin functions.
58  * @dev: the pinctrl device to be configured.
59  * @config: the state to be configured.
60  * @return: 0 in success
61  */
bcm283x_pinctrl_set_state(struct udevice * dev,struct udevice * config)62 int bcm283x_pinctrl_set_state(struct udevice *dev, struct udevice *config)
63 {
64 	u32 pin_arr[MAX_PINS_PER_BANK];
65 	u32 function;
66 	int i, len, pin_count = 0;
67 
68 	if (!dev_read_prop(config, "brcm,pins", &len) || !len ||
69 	    len & 0x3 || dev_read_u32_array(config, "brcm,pins", pin_arr,
70 						  len / sizeof(u32))) {
71 		debug("Failed reading pins array for pinconfig %s (%d)\n",
72 		      config->name, len);
73 		return -EINVAL;
74 	}
75 
76 	pin_count = len / sizeof(u32);
77 
78 	function = dev_read_u32_default(config, "brcm,function", -1);
79 	if (function < 0) {
80 		debug("Failed reading function for pinconfig %s (%d)\n",
81 		      config->name, function);
82 		return -EINVAL;
83 	}
84 
85 	for (i = 0; i < pin_count; i++)
86 		bcm2835_gpio_set_func_id(dev, pin_arr[i], function);
87 
88 	return 0;
89 }
90 
bcm283x_pinctrl_get_gpio_mux(struct udevice * dev,int banknum,int index)91 static int bcm283x_pinctrl_get_gpio_mux(struct udevice *dev, int banknum,
92 					int index)
93 {
94 	if (banknum != 0)
95 		return -EINVAL;
96 
97 	return bcm2835_gpio_get_func_id(dev, index);
98 }
99 
100 static const struct udevice_id bcm2835_pinctrl_id[] = {
101 	{.compatible = "brcm,bcm2835-gpio"},
102 	{}
103 };
104 
bcm283x_pinctl_probe(struct udevice * dev)105 int bcm283x_pinctl_probe(struct udevice *dev)
106 {
107 	struct bcm283x_pinctrl_priv *priv;
108 	int ret;
109 	struct udevice *pdev;
110 
111 	priv = dev_get_priv(dev);
112 	if (!priv) {
113 		debug("%s: Failed to get private\n", __func__);
114 		return -EINVAL;
115 	}
116 
117 	priv->base_reg = dev_read_addr_ptr(dev);
118 	if (priv->base_reg == (void *)FDT_ADDR_T_NONE) {
119 		debug("%s: Failed to get base address\n", __func__);
120 		return -EINVAL;
121 	}
122 
123 	/* Create GPIO device as well */
124 	ret = device_bind(dev, lists_driver_lookup_name("gpio_bcm2835"),
125 			  "gpio_bcm2835", NULL, dev_of_offset(dev), &pdev);
126 	if (ret) {
127 		/*
128 		 * While we really want the pinctrl driver to work to make
129 		 * devices go where they should go, the GPIO controller is
130 		 * not quite as crucial as it's only rarely used, so don't
131 		 * fail here.
132 		 */
133 		printf("Failed to bind GPIO driver\n");
134 	}
135 
136 	return 0;
137 }
138 
139 static struct pinctrl_ops bcm283x_pinctrl_ops = {
140 	.set_state	= bcm283x_pinctrl_set_state,
141 	.get_gpio_mux	= bcm283x_pinctrl_get_gpio_mux,
142 };
143 
144 U_BOOT_DRIVER(pinctrl_bcm283x) = {
145 	.name		= "bcm283x_pinctrl",
146 	.id		= UCLASS_PINCTRL,
147 	.of_match	= of_match_ptr(bcm2835_pinctrl_id),
148 	.priv_auto_alloc_size = sizeof(struct bcm283x_pinctrl_priv),
149 	.ops		= &bcm283x_pinctrl_ops,
150 	.probe		= bcm283x_pinctl_probe,
151 #if !CONFIG_IS_ENABLED(OF_CONTROL)
152 	.flags		= DM_FLAG_PRE_RELOC,
153 #endif
154 };
155