diff options
Diffstat (limited to 'drivers/gpio/gpio-gpio-mm.c')
| -rw-r--r-- | drivers/gpio/gpio-gpio-mm.c | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-gpio-mm.c b/drivers/gpio/gpio-gpio-mm.c new file mode 100644 index 000000000..2689671b6 --- /dev/null +++ b/drivers/gpio/gpio-gpio-mm.c @@ -0,0 +1,195 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * GPIO driver for the Diamond Systems GPIO-MM + * Copyright (C) 2016 William Breathitt Gray + * + * This driver supports the following Diamond Systems devices: GPIO-MM and + * GPIO-MM-12. + */ +#include <linux/device.h> +#include <linux/errno.h> +#include <linux/gpio/driver.h> +#include <linux/io.h> +#include <linux/ioport.h> +#include <linux/isa.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/moduleparam.h> + +#include "gpio-i8255.h" + +MODULE_IMPORT_NS(I8255); + +#define GPIOMM_EXTENT 8 +#define MAX_NUM_GPIOMM max_num_isa_dev(GPIOMM_EXTENT) + +static unsigned int base[MAX_NUM_GPIOMM]; +static unsigned int num_gpiomm; +module_param_hw_array(base, uint, ioport, &num_gpiomm, 0); +MODULE_PARM_DESC(base, "Diamond Systems GPIO-MM base addresses"); + +#define GPIOMM_NUM_PPI 2 + +/** + * struct gpiomm_gpio - GPIO device private data structure + * @chip: instance of the gpio_chip + * @ppi_state: Programmable Peripheral Interface group states + * @ppi: Programmable Peripheral Interface groups + */ +struct gpiomm_gpio { + struct gpio_chip chip; + struct i8255_state ppi_state[GPIOMM_NUM_PPI]; + struct i8255 __iomem *ppi; +}; + +static int gpiomm_gpio_get_direction(struct gpio_chip *chip, + unsigned int offset) +{ + struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip); + + if (i8255_get_direction(gpiommgpio->ppi_state, offset)) + return GPIO_LINE_DIRECTION_IN; + + return GPIO_LINE_DIRECTION_OUT; +} + +static int gpiomm_gpio_direction_input(struct gpio_chip *chip, + unsigned int offset) +{ + struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip); + + i8255_direction_input(gpiommgpio->ppi, gpiommgpio->ppi_state, offset); + + return 0; +} + +static int gpiomm_gpio_direction_output(struct gpio_chip *chip, + unsigned int offset, int value) +{ + struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip); + + i8255_direction_output(gpiommgpio->ppi, gpiommgpio->ppi_state, offset, + value); + + return 0; +} + +static int gpiomm_gpio_get(struct gpio_chip *chip, unsigned int offset) +{ + struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip); + + return i8255_get(gpiommgpio->ppi, offset); +} + +static int gpiomm_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask, + unsigned long *bits) +{ + struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip); + + i8255_get_multiple(gpiommgpio->ppi, mask, bits, chip->ngpio); + + return 0; +} + +static void gpiomm_gpio_set(struct gpio_chip *chip, unsigned int offset, + int value) +{ + struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip); + + i8255_set(gpiommgpio->ppi, gpiommgpio->ppi_state, offset, value); +} + +static void gpiomm_gpio_set_multiple(struct gpio_chip *chip, + unsigned long *mask, unsigned long *bits) +{ + struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip); + + i8255_set_multiple(gpiommgpio->ppi, gpiommgpio->ppi_state, mask, bits, + chip->ngpio); +} + +#define GPIOMM_NGPIO 48 +static const char *gpiomm_names[GPIOMM_NGPIO] = { + "Port 1A0", "Port 1A1", "Port 1A2", "Port 1A3", "Port 1A4", "Port 1A5", + "Port 1A6", "Port 1A7", "Port 1B0", "Port 1B1", "Port 1B2", "Port 1B3", + "Port 1B4", "Port 1B5", "Port 1B6", "Port 1B7", "Port 1C0", "Port 1C1", + "Port 1C2", "Port 1C3", "Port 1C4", "Port 1C5", "Port 1C6", "Port 1C7", + "Port 2A0", "Port 2A1", "Port 2A2", "Port 2A3", "Port 2A4", "Port 2A5", + "Port 2A6", "Port 2A7", "Port 2B0", "Port 2B1", "Port 2B2", "Port 2B3", + "Port 2B4", "Port 2B5", "Port 2B6", "Port 2B7", "Port 2C0", "Port 2C1", + "Port 2C2", "Port 2C3", "Port 2C4", "Port 2C5", "Port 2C6", "Port 2C7", +}; + +static void gpiomm_init_dio(struct i8255 __iomem *const ppi, + struct i8255_state *const ppi_state) +{ + const unsigned long ngpio = 24; + const unsigned long mask = GENMASK(ngpio - 1, 0); + const unsigned long bits = 0; + unsigned long i; + + /* Initialize all GPIO to output 0 */ + for (i = 0; i < GPIOMM_NUM_PPI; i++) { + i8255_mode0_output(&ppi[i]); + i8255_set_multiple(&ppi[i], &ppi_state[i], &mask, &bits, ngpio); + } +} + +static int gpiomm_probe(struct device *dev, unsigned int id) +{ + struct gpiomm_gpio *gpiommgpio; + const char *const name = dev_name(dev); + int err; + + gpiommgpio = devm_kzalloc(dev, sizeof(*gpiommgpio), GFP_KERNEL); + if (!gpiommgpio) + return -ENOMEM; + + if (!devm_request_region(dev, base[id], GPIOMM_EXTENT, name)) { + dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n", + base[id], base[id] + GPIOMM_EXTENT); + return -EBUSY; + } + + gpiommgpio->ppi = devm_ioport_map(dev, base[id], GPIOMM_EXTENT); + if (!gpiommgpio->ppi) + return -ENOMEM; + + gpiommgpio->chip.label = name; + gpiommgpio->chip.parent = dev; + gpiommgpio->chip.owner = THIS_MODULE; + gpiommgpio->chip.base = -1; + gpiommgpio->chip.ngpio = GPIOMM_NGPIO; + gpiommgpio->chip.names = gpiomm_names; + gpiommgpio->chip.get_direction = gpiomm_gpio_get_direction; + gpiommgpio->chip.direction_input = gpiomm_gpio_direction_input; + gpiommgpio->chip.direction_output = gpiomm_gpio_direction_output; + gpiommgpio->chip.get = gpiomm_gpio_get; + gpiommgpio->chip.get_multiple = gpiomm_gpio_get_multiple; + gpiommgpio->chip.set = gpiomm_gpio_set; + gpiommgpio->chip.set_multiple = gpiomm_gpio_set_multiple; + + i8255_state_init(gpiommgpio->ppi_state, GPIOMM_NUM_PPI); + gpiomm_init_dio(gpiommgpio->ppi, gpiommgpio->ppi_state); + + err = devm_gpiochip_add_data(dev, &gpiommgpio->chip, gpiommgpio); + if (err) { + dev_err(dev, "GPIO registering failed (%d)\n", err); + return err; + } + + return 0; +} + +static struct isa_driver gpiomm_driver = { + .probe = gpiomm_probe, + .driver = { + .name = "gpio-mm" + }, +}; + +module_isa_driver(gpiomm_driver, num_gpiomm); + +MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>"); +MODULE_DESCRIPTION("Diamond Systems GPIO-MM GPIO driver"); +MODULE_LICENSE("GPL v2"); |