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gerrit.devboardsforandroid.linaro.org / platform / external / u-boot / d9a5fad80857005703d46b6ea27217baa17eb142 / . / drivers / gpio / sifive-gpio.c
blob: 76d5a1d34eef134331052df92e9df9e20c6c6547 [file] [log] [blame]
Sagar Shrikant Kadamd26b4042019-10-01 10:00:46 -0700[diff] [blame]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
15static int sifive_gpio_probe(struct udevice *dev)
16{
17 struct sifive_gpio_platdata *plat = dev_get_platdata(dev);
18 struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
19 char name[18], *str;
20
21 sprintf(name, "gpio@%4lx_", (uintptr_t)plat->base);
22 str = strdup(name);
23 if (!str)
24 return -ENOMEM;
25 uc_priv->bank_name = str;
26
27 /*
28 * Use the gpio count mentioned in device tree,
29 * if not specified in dt, set NR_GPIOS as default
30 */
31 uc_priv->gpio_count = dev_read_u32_default(dev, "ngpios", NR_GPIOS);
32
33 return 0;
34}
35
36static void sifive_update_gpio_reg(void *bptr, u32 offset, bool value)
37{
38 void __iomem *ptr = (void __iomem *)bptr;
39
40 u32 bit = BIT(offset);
41 u32 old = readl(ptr);
42
43 if (value)
44 writel(old | bit, ptr);
45 else
46 writel(old & ~bit, ptr);
47}
48
49static int sifive_gpio_direction_input(struct udevice *dev, u32 offset)
50{
51 struct sifive_gpio_platdata *plat = dev_get_platdata(dev);
52 struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
53
54 if (offset > uc_priv->gpio_count)
55 return -EINVAL;
56
57 /* Configure gpio direction as input */
58 sifive_update_gpio_reg(plat->base + GPIO_INPUT_EN, offset, true);
59 sifive_update_gpio_reg(plat->base + GPIO_OUTPUT_EN, offset, false);
60
61 return 0;
62}
63
64static int sifive_gpio_direction_output(struct udevice *dev, u32 offset,
65 int value)
66{
67 struct sifive_gpio_platdata *plat = dev_get_platdata(dev);
68 struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
69
70 if (offset > uc_priv->gpio_count)
71 return -EINVAL;
72
73 /* Configure gpio direction as output */
74 sifive_update_gpio_reg(plat->base + GPIO_OUTPUT_EN, offset, true);
75 sifive_update_gpio_reg(plat->base + GPIO_INPUT_EN, offset, false);
76
77 /* Set the output state of the pin */
78 sifive_update_gpio_reg(plat->base + GPIO_OUTPUT_VAL, offset, value);
79
80 return 0;
81}
82
83static int sifive_gpio_get_value(struct udevice *dev, u32 offset)
84{
85 struct sifive_gpio_platdata *plat = dev_get_platdata(dev);
86 struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
87 int val;
88 int dir;
89
90 if (offset > uc_priv->gpio_count)
91 return -EINVAL;
92
93 /* Get direction of the pin */
94 dir = !(readl(plat->base + GPIO_OUTPUT_EN) & BIT(offset));
95
96 if (dir)
97 val = readl(plat->base + GPIO_INPUT_VAL) & BIT(offset);
98 else
99 val = readl(plat->base + GPIO_OUTPUT_VAL) & BIT(offset);
100
101 return val ? HIGH : LOW;
102}
103
104static int sifive_gpio_set_value(struct udevice *dev, u32 offset, int value)
105{
106 struct sifive_gpio_platdata *plat = dev_get_platdata(dev);
107 struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
108
109 if (offset > uc_priv->gpio_count)
110 return -EINVAL;
111
112 sifive_update_gpio_reg(plat->base + GPIO_OUTPUT_VAL, offset, value);
113
114 return 0;
115}
116
117static int sifive_gpio_get_function(struct udevice *dev, unsigned int offset)
118{
119 struct sifive_gpio_platdata *plat = dev_get_platdata(dev);
120 u32 outdir, indir, val;
121 struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
122
123 if (offset > uc_priv->gpio_count)
124 return -1;
125
126 /* Get direction of the pin */
127 outdir = readl(plat->base + GPIO_OUTPUT_EN) & BIT(offset);
128 indir = readl(plat->base + GPIO_INPUT_EN) & BIT(offset);
129
130 if (outdir)
131 /* Pin at specified offset is configured as output */
132 val = GPIOF_OUTPUT;
133 else if (indir)
134 /* Pin at specified offset is configured as input */
135 val = GPIOF_INPUT;
136 else
137 /*The requested GPIO is not set as input or output */
138 val = GPIOF_UNUSED;
139
140 return val;
141}
142
143static const struct udevice_id sifive_gpio_match[] = {
144 { .compatible = "sifive,gpio0" },
145 { }
146};
147
148static const struct dm_gpio_ops sifive_gpio_ops = {
149 .direction_input = sifive_gpio_direction_input,
150 .direction_output = sifive_gpio_direction_output,
151 .get_value = sifive_gpio_get_value,
152 .set_value = sifive_gpio_set_value,
153 .get_function = sifive_gpio_get_function,
154};
155
156static int sifive_gpio_ofdata_to_platdata(struct udevice *dev)
157{
158 struct sifive_gpio_platdata *plat = dev_get_platdata(dev);
159 fdt_addr_t addr;
160
161 addr = devfdt_get_addr(dev);
162 if (addr == FDT_ADDR_T_NONE)
163 return -EINVAL;
164
165 plat->base = (void *)addr;
166 return 0;
167}
168
169U_BOOT_DRIVER(gpio_sifive) = {
170 .name = "gpio_sifive",
171 .id = UCLASS_GPIO,
172 .of_match = sifive_gpio_match,
173 .ofdata_to_platdata = of_match_ptr(sifive_gpio_ofdata_to_platdata),
174 .platdata_auto_alloc_size = sizeof(struct sifive_gpio_platdata),
175 .ops = &sifive_gpio_ops,
176 .probe = sifive_gpio_probe,
177};