1 /*
2 * Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
3 *
4 * SPDX-License-Identifier: BSD-3-Clause
5 *
6 * ARM PL061 GPIO Driver.
7 * Reference to ARM DDI 0190B document.
8 *
9 */
10
11 #include <assert.h>
12 #include <errno.h>
13
14 #include <common/debug.h>
15 #include <drivers/arm/pl061_gpio.h>
16 #include <drivers/gpio.h>
17 #include <lib/cassert.h>
18 #include <lib/mmio.h>
19 #include <lib/utils.h>
20
21 #if !PLAT_PL061_MAX_GPIOS
22 # define PLAT_PL061_MAX_GPIOS 32
23 #endif /* PLAT_PL061_MAX_GPIOS */
24
25 CASSERT(PLAT_PL061_MAX_GPIOS > 0, assert_plat_pl061_max_gpios);
26
27 #define MAX_GPIO_DEVICES ((PLAT_PL061_MAX_GPIOS + \
28 (GPIOS_PER_PL061 - 1)) / GPIOS_PER_PL061)
29
30 #define PL061_GPIO_DIR 0x400
31
32 #define GPIOS_PER_PL061 8
33
34 static int pl061_get_direction(int gpio);
35 static void pl061_set_direction(int gpio, int direction);
36 static int pl061_get_value(int gpio);
37 static void pl061_set_value(int gpio, int value);
38
39 static uintptr_t pl061_reg_base[MAX_GPIO_DEVICES];
40
41 static const gpio_ops_t pl061_gpio_ops = {
42 .get_direction = pl061_get_direction,
43 .set_direction = pl061_set_direction,
44 .get_value = pl061_get_value,
45 .set_value = pl061_set_value,
46 };
47
pl061_get_direction(int gpio)48 static int pl061_get_direction(int gpio)
49 {
50 uintptr_t base_addr;
51 unsigned int data, offset;
52
53 assert((gpio >= 0) && (gpio < PLAT_PL061_MAX_GPIOS));
54
55 base_addr = pl061_reg_base[gpio / GPIOS_PER_PL061];
56 offset = gpio % GPIOS_PER_PL061;
57 data = mmio_read_8(base_addr + PL061_GPIO_DIR);
58 if (data & BIT(offset))
59 return GPIO_DIR_OUT;
60 return GPIO_DIR_IN;
61 }
62
pl061_set_direction(int gpio,int direction)63 static void pl061_set_direction(int gpio, int direction)
64 {
65 uintptr_t base_addr;
66 unsigned int data, offset;
67
68 assert((gpio >= 0) && (gpio < PLAT_PL061_MAX_GPIOS));
69
70 base_addr = pl061_reg_base[gpio / GPIOS_PER_PL061];
71 offset = gpio % GPIOS_PER_PL061;
72 if (direction == GPIO_DIR_OUT) {
73 data = mmio_read_8(base_addr + PL061_GPIO_DIR) | BIT(offset);
74 mmio_write_8(base_addr + PL061_GPIO_DIR, data);
75 } else {
76 data = mmio_read_8(base_addr + PL061_GPIO_DIR) & ~BIT(offset);
77 mmio_write_8(base_addr + PL061_GPIO_DIR, data);
78 }
79 }
80
81 /*
82 * The offset of GPIODATA register is 0.
83 * The values read from GPIODATA are determined for each bit, by the mask bit
84 * derived from the address used to access the data register, PADDR[9:2].
85 * Bits that are 1 in the address mask cause the corresponding bits in GPIODATA
86 * to be read, and bits that are 0 in the address mask cause the corresponding
87 * bits in GPIODATA to be read as 0, regardless of their value.
88 */
pl061_get_value(int gpio)89 static int pl061_get_value(int gpio)
90 {
91 uintptr_t base_addr;
92 unsigned int offset;
93
94 assert((gpio >= 0) && (gpio < PLAT_PL061_MAX_GPIOS));
95
96 base_addr = pl061_reg_base[gpio / GPIOS_PER_PL061];
97 offset = gpio % GPIOS_PER_PL061;
98 if (mmio_read_8(base_addr + BIT(offset + 2)))
99 return GPIO_LEVEL_HIGH;
100 return GPIO_LEVEL_LOW;
101 }
102
103 /*
104 * In order to write GPIODATA, the corresponding bits in the mask, resulting
105 * from the address bus, PADDR[9:2], must be HIGH. Otherwise the bit values
106 * remain unchanged by the write.
107 */
pl061_set_value(int gpio,int value)108 static void pl061_set_value(int gpio, int value)
109 {
110 uintptr_t base_addr;
111 int offset;
112
113 assert((gpio >= 0) && (gpio < PLAT_PL061_MAX_GPIOS));
114
115 base_addr = pl061_reg_base[gpio / GPIOS_PER_PL061];
116 offset = gpio % GPIOS_PER_PL061;
117 if (value == GPIO_LEVEL_HIGH)
118 mmio_write_8(base_addr + BIT(offset + 2), BIT(offset));
119 else
120 mmio_write_8(base_addr + BIT(offset + 2), 0);
121 }
122
123
124 /*
125 * Register the PL061 GPIO controller with a base address and the offset
126 * of start pin in this GPIO controller.
127 * This function is called after pl061_gpio_ops_init().
128 */
pl061_gpio_register(uintptr_t base_addr,int gpio_dev)129 void pl061_gpio_register(uintptr_t base_addr, int gpio_dev)
130 {
131 assert((gpio_dev >= 0) && (gpio_dev < MAX_GPIO_DEVICES));
132
133 pl061_reg_base[gpio_dev] = base_addr;
134 }
135
136 /*
137 * Initialize PL061 GPIO controller with the total GPIO numbers in SoC.
138 */
pl061_gpio_init(void)139 void pl061_gpio_init(void)
140 {
141 gpio_init(&pl061_gpio_ops);
142 }
143