1 // SPDX-License-Identifier: GPL-2.0+
2 /* Copyright (C) 2019 Stephan Gerhold */
3
4 #include <common.h>
5 #include <dm.h>
6 #include <asm/gpio.h>
7 #include <asm/io.h>
8
9 struct nmk_gpio_regs {
10 u32 dat; /* data */
11 u32 dats; /* data set */
12 u32 datc; /* data clear */
13 u32 pdis; /* pull disable */
14 u32 dir; /* direction */
15 u32 dirs; /* direction set */
16 u32 dirc; /* direction clear */
17 u32 slpm; /* sleep mode */
18 u32 afsla; /* alternate function select A */
19 u32 afslb; /* alternate function select B */
20 u32 lowemi; /* low EMI mode */
21 };
22
23 struct nmk_gpio {
24 struct nmk_gpio_regs *regs;
25 };
26
nmk_gpio_get_value(struct udevice * dev,unsigned offset)27 static int nmk_gpio_get_value(struct udevice *dev, unsigned offset)
28 {
29 struct nmk_gpio *priv = dev_get_priv(dev);
30
31 return !!(readl(&priv->regs->dat) & BIT(offset));
32 }
33
nmk_gpio_set_value(struct udevice * dev,unsigned offset,int value)34 static int nmk_gpio_set_value(struct udevice *dev, unsigned offset, int value)
35 {
36 struct nmk_gpio *priv = dev_get_priv(dev);
37
38 if (value)
39 writel(BIT(offset), &priv->regs->dats);
40 else
41 writel(BIT(offset), &priv->regs->datc);
42
43 return 0;
44 }
45
nmk_gpio_get_function(struct udevice * dev,unsigned offset)46 static int nmk_gpio_get_function(struct udevice *dev, unsigned offset)
47 {
48 struct nmk_gpio *priv = dev_get_priv(dev);
49
50 if (readl(&priv->regs->afsla) & BIT(offset) ||
51 readl(&priv->regs->afslb) & BIT(offset))
52 return GPIOF_FUNC;
53
54 if (readl(&priv->regs->dir) & BIT(offset))
55 return GPIOF_OUTPUT;
56 else
57 return GPIOF_INPUT;
58 }
59
nmk_gpio_direction_input(struct udevice * dev,unsigned offset)60 static int nmk_gpio_direction_input(struct udevice *dev, unsigned offset)
61 {
62 struct nmk_gpio *priv = dev_get_priv(dev);
63
64 writel(BIT(offset), &priv->regs->dirc);
65 return 0;
66 }
67
nmk_gpio_direction_output(struct udevice * dev,unsigned offset,int value)68 static int nmk_gpio_direction_output(struct udevice *dev, unsigned offset,
69 int value)
70 {
71 struct nmk_gpio *priv = dev_get_priv(dev);
72
73 writel(BIT(offset), &priv->regs->dirs);
74 return nmk_gpio_set_value(dev, offset, value);
75 }
76
77 static const struct dm_gpio_ops nmk_gpio_ops = {
78 .get_value = nmk_gpio_get_value,
79 .set_value = nmk_gpio_set_value,
80 .get_function = nmk_gpio_get_function,
81 .direction_input = nmk_gpio_direction_input,
82 .direction_output = nmk_gpio_direction_output,
83 };
84
nmk_gpio_probe(struct udevice * dev)85 static int nmk_gpio_probe(struct udevice *dev)
86 {
87 struct nmk_gpio *priv = dev_get_priv(dev);
88 struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
89 char buf[20];
90 u32 bank;
91 int ret;
92
93 priv->regs = dev_read_addr_ptr(dev);
94 if (!priv->regs)
95 return -EINVAL;
96
97 ret = dev_read_u32(dev, "gpio-bank", &bank);
98 if (ret < 0) {
99 printf("nmk_gpio(%s): Failed to read gpio-bank\n", dev->name);
100 return ret;
101 }
102
103 sprintf(buf, "nmk%u-gpio", bank);
104 uc_priv->bank_name = strdup(buf);
105 if (!uc_priv->bank_name)
106 return -ENOMEM;
107
108 uc_priv->gpio_count = sizeof(priv->regs->dat) * BITS_PER_BYTE;
109
110 return 0;
111 }
112
113 static const struct udevice_id nmk_gpio_ids[] = {
114 { .compatible = "st,nomadik-gpio" },
115 { }
116 };
117
118 U_BOOT_DRIVER(gpio_nmk) = {
119 .name = "nmk_gpio",
120 .id = UCLASS_GPIO,
121 .of_match = nmk_gpio_ids,
122 .probe = nmk_gpio_probe,
123 .ops = &nmk_gpio_ops,
124 .priv_auto = sizeof(struct nmk_gpio),
125 };
126