1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * GPIO driver for the Diamond Systems GPIO-MM
4 * Copyright (C) 2016 William Breathitt Gray
5 *
6 * This driver supports the following Diamond Systems devices: GPIO-MM and
7 * GPIO-MM-12.
8 */
9 #include <linux/device.h>
10 #include <linux/errno.h>
11 #include <linux/gpio/driver.h>
12 #include <linux/io.h>
13 #include <linux/ioport.h>
14 #include <linux/isa.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/moduleparam.h>
18
19 #include "gpio-i8255.h"
20
21 MODULE_IMPORT_NS(I8255);
22
23 #define GPIOMM_EXTENT 8
24 #define MAX_NUM_GPIOMM max_num_isa_dev(GPIOMM_EXTENT)
25
26 static unsigned int base[MAX_NUM_GPIOMM];
27 static unsigned int num_gpiomm;
28 module_param_hw_array(base, uint, ioport, &num_gpiomm, 0);
29 MODULE_PARM_DESC(base, "Diamond Systems GPIO-MM base addresses");
30
31 #define GPIOMM_NUM_PPI 2
32
33 /**
34 * struct gpiomm_gpio - GPIO device private data structure
35 * @chip: instance of the gpio_chip
36 * @ppi_state: Programmable Peripheral Interface group states
37 * @ppi: Programmable Peripheral Interface groups
38 */
39 struct gpiomm_gpio {
40 struct gpio_chip chip;
41 struct i8255_state ppi_state[GPIOMM_NUM_PPI];
42 struct i8255 __iomem *ppi;
43 };
44
gpiomm_gpio_get_direction(struct gpio_chip * chip,unsigned int offset)45 static int gpiomm_gpio_get_direction(struct gpio_chip *chip,
46 unsigned int offset)
47 {
48 struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip);
49
50 if (i8255_get_direction(gpiommgpio->ppi_state, offset))
51 return GPIO_LINE_DIRECTION_IN;
52
53 return GPIO_LINE_DIRECTION_OUT;
54 }
55
gpiomm_gpio_direction_input(struct gpio_chip * chip,unsigned int offset)56 static int gpiomm_gpio_direction_input(struct gpio_chip *chip,
57 unsigned int offset)
58 {
59 struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip);
60
61 i8255_direction_input(gpiommgpio->ppi, gpiommgpio->ppi_state, offset);
62
63 return 0;
64 }
65
gpiomm_gpio_direction_output(struct gpio_chip * chip,unsigned int offset,int value)66 static int gpiomm_gpio_direction_output(struct gpio_chip *chip,
67 unsigned int offset, int value)
68 {
69 struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip);
70
71 i8255_direction_output(gpiommgpio->ppi, gpiommgpio->ppi_state, offset,
72 value);
73
74 return 0;
75 }
76
gpiomm_gpio_get(struct gpio_chip * chip,unsigned int offset)77 static int gpiomm_gpio_get(struct gpio_chip *chip, unsigned int offset)
78 {
79 struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip);
80
81 return i8255_get(gpiommgpio->ppi, offset);
82 }
83
gpiomm_gpio_get_multiple(struct gpio_chip * chip,unsigned long * mask,unsigned long * bits)84 static int gpiomm_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask,
85 unsigned long *bits)
86 {
87 struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip);
88
89 i8255_get_multiple(gpiommgpio->ppi, mask, bits, chip->ngpio);
90
91 return 0;
92 }
93
gpiomm_gpio_set(struct gpio_chip * chip,unsigned int offset,int value)94 static void gpiomm_gpio_set(struct gpio_chip *chip, unsigned int offset,
95 int value)
96 {
97 struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip);
98
99 i8255_set(gpiommgpio->ppi, gpiommgpio->ppi_state, offset, value);
100 }
101
gpiomm_gpio_set_multiple(struct gpio_chip * chip,unsigned long * mask,unsigned long * bits)102 static void gpiomm_gpio_set_multiple(struct gpio_chip *chip,
103 unsigned long *mask, unsigned long *bits)
104 {
105 struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip);
106
107 i8255_set_multiple(gpiommgpio->ppi, gpiommgpio->ppi_state, mask, bits,
108 chip->ngpio);
109 }
110
111 #define GPIOMM_NGPIO 48
112 static const char *gpiomm_names[GPIOMM_NGPIO] = {
113 "Port 1A0", "Port 1A1", "Port 1A2", "Port 1A3", "Port 1A4", "Port 1A5",
114 "Port 1A6", "Port 1A7", "Port 1B0", "Port 1B1", "Port 1B2", "Port 1B3",
115 "Port 1B4", "Port 1B5", "Port 1B6", "Port 1B7", "Port 1C0", "Port 1C1",
116 "Port 1C2", "Port 1C3", "Port 1C4", "Port 1C5", "Port 1C6", "Port 1C7",
117 "Port 2A0", "Port 2A1", "Port 2A2", "Port 2A3", "Port 2A4", "Port 2A5",
118 "Port 2A6", "Port 2A7", "Port 2B0", "Port 2B1", "Port 2B2", "Port 2B3",
119 "Port 2B4", "Port 2B5", "Port 2B6", "Port 2B7", "Port 2C0", "Port 2C1",
120 "Port 2C2", "Port 2C3", "Port 2C4", "Port 2C5", "Port 2C6", "Port 2C7",
121 };
122
gpiomm_init_dio(struct i8255 __iomem * const ppi,struct i8255_state * const ppi_state)123 static void gpiomm_init_dio(struct i8255 __iomem *const ppi,
124 struct i8255_state *const ppi_state)
125 {
126 const unsigned long ngpio = 24;
127 const unsigned long mask = GENMASK(ngpio - 1, 0);
128 const unsigned long bits = 0;
129 unsigned long i;
130
131 /* Initialize all GPIO to output 0 */
132 for (i = 0; i < GPIOMM_NUM_PPI; i++) {
133 i8255_mode0_output(&ppi[i]);
134 i8255_set_multiple(&ppi[i], &ppi_state[i], &mask, &bits, ngpio);
135 }
136 }
137
gpiomm_probe(struct device * dev,unsigned int id)138 static int gpiomm_probe(struct device *dev, unsigned int id)
139 {
140 struct gpiomm_gpio *gpiommgpio;
141 const char *const name = dev_name(dev);
142 int err;
143
144 gpiommgpio = devm_kzalloc(dev, sizeof(*gpiommgpio), GFP_KERNEL);
145 if (!gpiommgpio)
146 return -ENOMEM;
147
148 if (!devm_request_region(dev, base[id], GPIOMM_EXTENT, name)) {
149 dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n",
150 base[id], base[id] + GPIOMM_EXTENT);
151 return -EBUSY;
152 }
153
154 gpiommgpio->ppi = devm_ioport_map(dev, base[id], GPIOMM_EXTENT);
155 if (!gpiommgpio->ppi)
156 return -ENOMEM;
157
158 gpiommgpio->chip.label = name;
159 gpiommgpio->chip.parent = dev;
160 gpiommgpio->chip.owner = THIS_MODULE;
161 gpiommgpio->chip.base = -1;
162 gpiommgpio->chip.ngpio = GPIOMM_NGPIO;
163 gpiommgpio->chip.names = gpiomm_names;
164 gpiommgpio->chip.get_direction = gpiomm_gpio_get_direction;
165 gpiommgpio->chip.direction_input = gpiomm_gpio_direction_input;
166 gpiommgpio->chip.direction_output = gpiomm_gpio_direction_output;
167 gpiommgpio->chip.get = gpiomm_gpio_get;
168 gpiommgpio->chip.get_multiple = gpiomm_gpio_get_multiple;
169 gpiommgpio->chip.set = gpiomm_gpio_set;
170 gpiommgpio->chip.set_multiple = gpiomm_gpio_set_multiple;
171
172 i8255_state_init(gpiommgpio->ppi_state, GPIOMM_NUM_PPI);
173 gpiomm_init_dio(gpiommgpio->ppi, gpiommgpio->ppi_state);
174
175 err = devm_gpiochip_add_data(dev, &gpiommgpio->chip, gpiommgpio);
176 if (err) {
177 dev_err(dev, "GPIO registering failed (%d)\n", err);
178 return err;
179 }
180
181 return 0;
182 }
183
184 static struct isa_driver gpiomm_driver = {
185 .probe = gpiomm_probe,
186 .driver = {
187 .name = "gpio-mm"
188 },
189 };
190
191 module_isa_driver(gpiomm_driver, num_gpiomm);
192
193 MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>");
194 MODULE_DESCRIPTION("Diamond Systems GPIO-MM GPIO driver");
195 MODULE_LICENSE("GPL v2");
196
