diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
commit | 76cb841cb886eef6b3bee341a2266c76578724ad (patch) | |
tree | f5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /drivers/gpio/gpio-gpio-mm.c | |
parent | Initial commit. (diff) | |
download | linux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip |
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/gpio/gpio-gpio-mm.c')
-rw-r--r-- | drivers/gpio/gpio-gpio-mm.c | 354 |
1 files changed, 354 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..b56ff2efb --- /dev/null +++ b/drivers/gpio/gpio-gpio-mm.c @@ -0,0 +1,354 @@ +/* + * GPIO driver for the Diamond Systems GPIO-MM + * Copyright (C) 2016 William Breathitt Gray + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License, version 2, as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * This driver supports the following Diamond Systems devices: GPIO-MM and + * GPIO-MM-12. + */ +#include <linux/bitmap.h> +#include <linux/bitops.h> +#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 <linux/spinlock.h> + +#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"); + +/** + * struct gpiomm_gpio - GPIO device private data structure + * @chip: instance of the gpio_chip + * @io_state: bit I/O state (whether bit is set to input or output) + * @out_state: output bits state + * @control: Control registers state + * @lock: synchronization lock to prevent I/O race conditions + * @base: base port address of the GPIO device + */ +struct gpiomm_gpio { + struct gpio_chip chip; + unsigned char io_state[6]; + unsigned char out_state[6]; + unsigned char control[2]; + spinlock_t lock; + unsigned int base; +}; + +static int gpiomm_gpio_get_direction(struct gpio_chip *chip, + unsigned int offset) +{ + struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip); + const unsigned int port = offset / 8; + const unsigned int mask = BIT(offset % 8); + + return !!(gpiommgpio->io_state[port] & mask); +} + +static int gpiomm_gpio_direction_input(struct gpio_chip *chip, + unsigned int offset) +{ + struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip); + const unsigned int io_port = offset / 8; + const unsigned int control_port = io_port / 3; + const unsigned int control_addr = gpiommgpio->base + 3 + control_port*4; + unsigned long flags; + unsigned int control; + + spin_lock_irqsave(&gpiommgpio->lock, flags); + + /* Check if configuring Port C */ + if (io_port == 2 || io_port == 5) { + /* Port C can be configured by nibble */ + if (offset % 8 > 3) { + gpiommgpio->io_state[io_port] |= 0xF0; + gpiommgpio->control[control_port] |= BIT(3); + } else { + gpiommgpio->io_state[io_port] |= 0x0F; + gpiommgpio->control[control_port] |= BIT(0); + } + } else { + gpiommgpio->io_state[io_port] |= 0xFF; + if (io_port == 0 || io_port == 3) + gpiommgpio->control[control_port] |= BIT(4); + else + gpiommgpio->control[control_port] |= BIT(1); + } + + control = BIT(7) | gpiommgpio->control[control_port]; + outb(control, control_addr); + + spin_unlock_irqrestore(&gpiommgpio->lock, flags); + + 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); + const unsigned int io_port = offset / 8; + const unsigned int control_port = io_port / 3; + const unsigned int mask = BIT(offset % 8); + const unsigned int control_addr = gpiommgpio->base + 3 + control_port*4; + const unsigned int out_port = (io_port > 2) ? io_port + 1 : io_port; + unsigned long flags; + unsigned int control; + + spin_lock_irqsave(&gpiommgpio->lock, flags); + + /* Check if configuring Port C */ + if (io_port == 2 || io_port == 5) { + /* Port C can be configured by nibble */ + if (offset % 8 > 3) { + gpiommgpio->io_state[io_port] &= 0x0F; + gpiommgpio->control[control_port] &= ~BIT(3); + } else { + gpiommgpio->io_state[io_port] &= 0xF0; + gpiommgpio->control[control_port] &= ~BIT(0); + } + } else { + gpiommgpio->io_state[io_port] &= 0x00; + if (io_port == 0 || io_port == 3) + gpiommgpio->control[control_port] &= ~BIT(4); + else + gpiommgpio->control[control_port] &= ~BIT(1); + } + + if (value) + gpiommgpio->out_state[io_port] |= mask; + else + gpiommgpio->out_state[io_port] &= ~mask; + + control = BIT(7) | gpiommgpio->control[control_port]; + outb(control, control_addr); + + outb(gpiommgpio->out_state[io_port], gpiommgpio->base + out_port); + + spin_unlock_irqrestore(&gpiommgpio->lock, flags); + + return 0; +} + +static int gpiomm_gpio_get(struct gpio_chip *chip, unsigned int offset) +{ + struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip); + const unsigned int port = offset / 8; + const unsigned int mask = BIT(offset % 8); + const unsigned int in_port = (port > 2) ? port + 1 : port; + unsigned long flags; + unsigned int port_state; + + spin_lock_irqsave(&gpiommgpio->lock, flags); + + /* ensure that GPIO is set for input */ + if (!(gpiommgpio->io_state[port] & mask)) { + spin_unlock_irqrestore(&gpiommgpio->lock, flags); + return -EINVAL; + } + + port_state = inb(gpiommgpio->base + in_port); + + spin_unlock_irqrestore(&gpiommgpio->lock, flags); + + return !!(port_state & mask); +} + +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); + size_t i; + static const size_t ports[] = { 0, 1, 2, 4, 5, 6 }; + const unsigned int gpio_reg_size = 8; + unsigned int bits_offset; + size_t word_index; + unsigned int word_offset; + unsigned long word_mask; + const unsigned long port_mask = GENMASK(gpio_reg_size - 1, 0); + unsigned long port_state; + + /* clear bits array to a clean slate */ + bitmap_zero(bits, chip->ngpio); + + /* get bits are evaluated a gpio port register at a time */ + for (i = 0; i < ARRAY_SIZE(ports); i++) { + /* gpio offset in bits array */ + bits_offset = i * gpio_reg_size; + + /* word index for bits array */ + word_index = BIT_WORD(bits_offset); + + /* gpio offset within current word of bits array */ + word_offset = bits_offset % BITS_PER_LONG; + + /* mask of get bits for current gpio within current word */ + word_mask = mask[word_index] & (port_mask << word_offset); + if (!word_mask) { + /* no get bits in this port so skip to next one */ + continue; + } + + /* read bits from current gpio port */ + port_state = inb(gpiommgpio->base + ports[i]); + + /* store acquired bits at respective bits array offset */ + bits[word_index] |= port_state << word_offset; + } + + 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); + const unsigned int port = offset / 8; + const unsigned int mask = BIT(offset % 8); + const unsigned int out_port = (port > 2) ? port + 1 : port; + unsigned long flags; + + spin_lock_irqsave(&gpiommgpio->lock, flags); + + if (value) + gpiommgpio->out_state[port] |= mask; + else + gpiommgpio->out_state[port] &= ~mask; + + outb(gpiommgpio->out_state[port], gpiommgpio->base + out_port); + + spin_unlock_irqrestore(&gpiommgpio->lock, flags); +} + +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); + unsigned int i; + const unsigned int gpio_reg_size = 8; + unsigned int port; + unsigned int out_port; + unsigned int bitmask; + unsigned long flags; + + /* set bits are evaluated a gpio register size at a time */ + for (i = 0; i < chip->ngpio; i += gpio_reg_size) { + /* no more set bits in this mask word; skip to the next word */ + if (!mask[BIT_WORD(i)]) { + i = (BIT_WORD(i) + 1) * BITS_PER_LONG - gpio_reg_size; + continue; + } + + port = i / gpio_reg_size; + out_port = (port > 2) ? port + 1 : port; + bitmask = mask[BIT_WORD(i)] & bits[BIT_WORD(i)]; + + spin_lock_irqsave(&gpiommgpio->lock, flags); + + /* update output state data and set device gpio register */ + gpiommgpio->out_state[port] &= ~mask[BIT_WORD(i)]; + gpiommgpio->out_state[port] |= bitmask; + outb(gpiommgpio->out_state[port], gpiommgpio->base + out_port); + + spin_unlock_irqrestore(&gpiommgpio->lock, flags); + + /* prepare for next gpio register set */ + mask[BIT_WORD(i)] >>= gpio_reg_size; + bits[BIT_WORD(i)] >>= gpio_reg_size; + } +} + +#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 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->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; + gpiommgpio->base = base[id]; + + spin_lock_init(&gpiommgpio->lock); + + err = devm_gpiochip_add_data(dev, &gpiommgpio->chip, gpiommgpio); + if (err) { + dev_err(dev, "GPIO registering failed (%d)\n", err); + return err; + } + + /* initialize all GPIO as output */ + outb(0x80, base[id] + 3); + outb(0x00, base[id]); + outb(0x00, base[id] + 1); + outb(0x00, base[id] + 2); + outb(0x80, base[id] + 7); + outb(0x00, base[id] + 4); + outb(0x00, base[id] + 5); + outb(0x00, base[id] + 6); + + 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"); |