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