1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * SiFive GPIO driver
4 *
5 * Copyright (C) 2019 SiFive, Inc.
6 */
7
8 #include <common.h>
9 #include <dm.h>
10 #include <asm/arch/gpio.h>
11 #include <asm/io.h>
12 #include <errno.h>
13 #include <asm/gpio.h>
14 #include <linux/bitops.h>
15
sifive_gpio_probe(struct udevice * dev)16 static int sifive_gpio_probe(struct udevice *dev)
17 {
18 struct sifive_gpio_plat *plat = dev_get_plat(dev);
19 struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
20 char name[18], *str;
21
22 sprintf(name, "gpio@%4lx_", (uintptr_t)plat->base);
23 str = strdup(name);
24 if (!str)
25 return -ENOMEM;
26 uc_priv->bank_name = str;
27
28 /*
29 * Use the gpio count mentioned in device tree,
30 * if not specified in dt, set NR_GPIOS as default
31 */
32 uc_priv->gpio_count = dev_read_u32_default(dev, "ngpios", NR_GPIOS);
33
34 return 0;
35 }
36
sifive_update_gpio_reg(void * bptr,u32 offset,bool value)37 static void sifive_update_gpio_reg(void *bptr, u32 offset, bool value)
38 {
39 void __iomem *ptr = (void __iomem *)bptr;
40
41 u32 bit = BIT(offset);
42 u32 old = readl(ptr);
43
44 if (value)
45 writel(old | bit, ptr);
46 else
47 writel(old & ~bit, ptr);
48 }
49
sifive_gpio_direction_input(struct udevice * dev,u32 offset)50 static int sifive_gpio_direction_input(struct udevice *dev, u32 offset)
51 {
52 struct sifive_gpio_plat *plat = dev_get_plat(dev);
53 struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
54
55 if (offset > uc_priv->gpio_count)
56 return -EINVAL;
57
58 /* Configure gpio direction as input */
59 sifive_update_gpio_reg(plat->base + GPIO_INPUT_EN, offset, true);
60 sifive_update_gpio_reg(plat->base + GPIO_OUTPUT_EN, offset, false);
61
62 return 0;
63 }
64
sifive_gpio_direction_output(struct udevice * dev,u32 offset,int value)65 static int sifive_gpio_direction_output(struct udevice *dev, u32 offset,
66 int value)
67 {
68 struct sifive_gpio_plat *plat = dev_get_plat(dev);
69 struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
70
71 if (offset > uc_priv->gpio_count)
72 return -EINVAL;
73
74 /* Configure gpio direction as output */
75 sifive_update_gpio_reg(plat->base + GPIO_OUTPUT_EN, offset, true);
76 sifive_update_gpio_reg(plat->base + GPIO_INPUT_EN, offset, false);
77
78 /* Set the output state of the pin */
79 sifive_update_gpio_reg(plat->base + GPIO_OUTPUT_VAL, offset, value);
80
81 return 0;
82 }
83
sifive_gpio_get_value(struct udevice * dev,u32 offset)84 static int sifive_gpio_get_value(struct udevice *dev, u32 offset)
85 {
86 struct sifive_gpio_plat *plat = dev_get_plat(dev);
87 struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
88 int val;
89 int dir;
90
91 if (offset > uc_priv->gpio_count)
92 return -EINVAL;
93
94 /* Get direction of the pin */
95 dir = !(readl(plat->base + GPIO_OUTPUT_EN) & BIT(offset));
96
97 if (dir)
98 val = readl(plat->base + GPIO_INPUT_VAL) & BIT(offset);
99 else
100 val = readl(plat->base + GPIO_OUTPUT_VAL) & BIT(offset);
101
102 return val ? HIGH : LOW;
103 }
104
sifive_gpio_set_value(struct udevice * dev,u32 offset,int value)105 static int sifive_gpio_set_value(struct udevice *dev, u32 offset, int value)
106 {
107 struct sifive_gpio_plat *plat = dev_get_plat(dev);
108 struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
109
110 if (offset > uc_priv->gpio_count)
111 return -EINVAL;
112
113 sifive_update_gpio_reg(plat->base + GPIO_OUTPUT_VAL, offset, value);
114
115 return 0;
116 }
117
sifive_gpio_get_function(struct udevice * dev,unsigned int offset)118 static int sifive_gpio_get_function(struct udevice *dev, unsigned int offset)
119 {
120 struct sifive_gpio_plat *plat = dev_get_plat(dev);
121 u32 outdir, indir, val;
122 struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
123
124 if (offset > uc_priv->gpio_count)
125 return -1;
126
127 /* Get direction of the pin */
128 outdir = readl(plat->base + GPIO_OUTPUT_EN) & BIT(offset);
129 indir = readl(plat->base + GPIO_INPUT_EN) & BIT(offset);
130
131 if (outdir)
132 /* Pin at specified offset is configured as output */
133 val = GPIOF_OUTPUT;
134 else if (indir)
135 /* Pin at specified offset is configured as input */
136 val = GPIOF_INPUT;
137 else
138 /*The requested GPIO is not set as input or output */
139 val = GPIOF_UNUSED;
140
141 return val;
142 }
143
144 static const struct udevice_id sifive_gpio_match[] = {
145 { .compatible = "sifive,gpio0" },
146 { }
147 };
148
149 static const struct dm_gpio_ops sifive_gpio_ops = {
150 .direction_input = sifive_gpio_direction_input,
151 .direction_output = sifive_gpio_direction_output,
152 .get_value = sifive_gpio_get_value,
153 .set_value = sifive_gpio_set_value,
154 .get_function = sifive_gpio_get_function,
155 };
156
sifive_gpio_of_to_plat(struct udevice * dev)157 static int sifive_gpio_of_to_plat(struct udevice *dev)
158 {
159 struct sifive_gpio_plat *plat = dev_get_plat(dev);
160 fdt_addr_t addr;
161
162 addr = dev_read_addr(dev);
163 if (addr == FDT_ADDR_T_NONE)
164 return -EINVAL;
165
166 plat->base = (void *)addr;
167 return 0;
168 }
169
170 U_BOOT_DRIVER(gpio_sifive) = {
171 .name = "gpio_sifive",
172 .id = UCLASS_GPIO,
173 .of_match = sifive_gpio_match,
174 .of_to_plat = of_match_ptr(sifive_gpio_of_to_plat),
175 .plat_auto = sizeof(struct sifive_gpio_plat),
176 .ops = &sifive_gpio_ops,
177 .probe = sifive_gpio_probe,
178 };
179