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
 21MODULE_IMPORT_NS(I8255);
 22
 23#define GPIOMM_EXTENT 8
 24#define MAX_NUM_GPIOMM max_num_isa_dev(GPIOMM_EXTENT)
 25
 26static unsigned int base[MAX_NUM_GPIOMM];
 27static unsigned int num_gpiomm;
 28module_param_hw_array(base, uint, ioport, &num_gpiomm, 0);
 29MODULE_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 */
 39struct gpiomm_gpio {
 40	struct gpio_chip chip;
 41	struct i8255_state ppi_state[GPIOMM_NUM_PPI];
 42	struct i8255 __iomem *ppi;
 43};
 44
 45static 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
 56static 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
 66static 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
 77static 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
 84static 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
 94static 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
102static 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
112static 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
123static 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
138static 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
184static struct isa_driver gpiomm_driver = {
185	.probe = gpiomm_probe,
186	.driver = {
187		.name = "gpio-mm"
188	},
189};
190
191module_isa_driver(gpiomm_driver, num_gpiomm);
192
193MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>");
194MODULE_DESCRIPTION("Diamond Systems GPIO-MM GPIO driver");
195MODULE_LICENSE("GPL v2");