diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-03-17 21:05:32 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-03-17 21:05:32 -0700 |
commit | 1a46712aa99594eabe1e9aeedf115dfff0db1dfd (patch) | |
tree | 61240865e6b55e2f2b2c174b333c2a097bd4f31e /drivers/gpio/gpio-ws16c48.c | |
parent | 82b666eee71618b7ca812ee529af116582617dec (diff) | |
parent | ccbd805aa934dd1b863ef115a9c55f119b2388cf (diff) | |
download | kernel_replicant_linux-1a46712aa99594eabe1e9aeedf115dfff0db1dfd.tar.gz kernel_replicant_linux-1a46712aa99594eabe1e9aeedf115dfff0db1dfd.tar.bz2 kernel_replicant_linux-1a46712aa99594eabe1e9aeedf115dfff0db1dfd.zip |
Merge tag 'gpio-v4.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio
Pull GPIO updates from Linus Walleij:
"This is the bulk of GPIO changes for kernel v4.6. There is quite a
lot of interesting stuff going on.
The patches to other subsystems and arch-wide are ACKed as far as
possible, though I consider things like per-arch <asm/gpio.h> as
essentially a part of the GPIO subsystem so it should not be needed.
Core changes:
- The gpio_chip is now a *real device*. Until now the gpio chips
were just piggybacking the parent device or (gasp) floating in
space outside of the device model.
We now finally make GPIO chips devices. The gpio_chip will create
a gpio_device which contains a struct device, and this gpio_device
struct is kept private. Anything that needs to be kept private
from the rest of the kernel will gradually be moved over to the
gpio_device.
- As a result of making the gpio_device a real device, we have added
resource management, so devm_gpiochip_add_data() will cut down on
overhead and reduce code lines. A huge slew of patches convert
almost all drivers in the subsystem to use this.
- Building on making the GPIO a real device, we add the first step of
a new userspace ABI: the GPIO character device. We take small
steps here, so we first add a pure *information* ABI and the tool
"lsgpio" that will list all GPIO devices on the system and all
lines on these devices.
We can now discover GPIOs properly from userspace. We still have
not come up with a way to actually *use* GPIOs from userspace.
- To encourage people to use the character device for the future, we
have it always-enabled when using GPIO. The old sysfs ABI is still
opt-in (and can be used in parallel), but is marked as deprecated.
We will keep it around for the foreseeable future, but it will not
be extended to cover ever more use cases.
Cleanup:
- Bjorn Helgaas removed a whole slew of per-architecture <asm/gpio.h>
includes.
This dates back to when GPIO was an opt-in feature and no shared
library even existed: just a header file with proper prototypes was
provided and all semantics were up to the arch to implement. These
patches make the GPIO chip even more a proper device and cleans out
leftovers of the old in-kernel API here and there.
Still some cruft is left but it's very little now.
- There is still some clamping of return values for .get() going on,
but we now return sane values in the vast majority of drivers and
the errorpath is sanitized. Some patches for powerpc, blackfin and
unicore still drop in.
- We continue to switch the ARM, MIPS, blackfin, m68k local GPIO
implementations to use gpiochip_add_data() and cut down on code
lines.
- MPC8xxx is converted to use the generic GPIO helpers.
- ATH79 is converted to use the generic GPIO helpers.
New drivers:
- WinSystems WS16C48
- Acces 104-DIO-48E
- F81866 (a F7188x variant)
- Qoric (a MPC8xxx variant)
- TS-4800
- SPI serializers (pisosr): simple 74xx shift registers connected to
SPI to obtain a dirt-cheap output-only GPIO expander.
- Texas Instruments TPIC2810
- Texas Instruments TPS65218
- Texas Instruments TPS65912
- X-Gene (ARM64) standby GPIO controller"
* tag 'gpio-v4.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (194 commits)
Revert "Share upstreaming patches"
gpio: mcp23s08: Fix clearing of interrupt.
gpiolib: Fix comment referring to gpio_*() in gpiod_*()
gpio: pca953x: Fix pca953x_gpio_set_multiple() on 64-bit
gpio: xgene: Fix kconfig for standby GIPO contoller
gpio: Add generic serializer DT binding
gpio: uapi: use 0xB4 as ioctl() major
gpio: tps65912: fix bad merge
Revert "gpio: lp3943: Drop pin_used and lp3943_gpio_request/lp3943_gpio_free"
gpio: omap: drop dev field from gpio_bank structure
gpio: mpc8xxx: Slightly update the code for better readability
gpio: mpc8xxx: Remove *read_reg and *write_reg from struct mpc8xxx_gpio_chip
gpio: mpc8xxx: Fixup setting gpio direction output
gpio: mcp23s08: Add support for mcp23s18
dt-bindings: gpio: altera: Fix altr,interrupt-type property
gpio: add driver for MEN 16Z127 GPIO controller
gpio: lp3943: Drop pin_used and lp3943_gpio_request/lp3943_gpio_free
gpio: timberdale: Switch to devm_ioremap_resource()
gpio: ts4800: Add IMX51 dependency
gpiolib: rewrite gpiodev_add_to_list
...
Diffstat (limited to 'drivers/gpio/gpio-ws16c48.c')
-rw-r--r-- | drivers/gpio/gpio-ws16c48.c | 427 |
1 files changed, 427 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-ws16c48.c b/drivers/gpio/gpio-ws16c48.c new file mode 100644 index 000000000000..51f41e8fd21e --- /dev/null +++ b/drivers/gpio/gpio-ws16c48.c @@ -0,0 +1,427 @@ +/* + * GPIO driver for the WinSystems WS16C48 + * 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. + */ +#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/interrupt.h> +#include <linux/irqdesc.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/platform_device.h> +#include <linux/spinlock.h> + +static unsigned ws16c48_base; +module_param(ws16c48_base, uint, 0); +MODULE_PARM_DESC(ws16c48_base, "WinSystems WS16C48 base address"); +static unsigned ws16c48_irq; +module_param(ws16c48_irq, uint, 0); +MODULE_PARM_DESC(ws16c48_irq, "WinSystems WS16C48 interrupt line number"); + +/** + * struct ws16c48_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 + * @lock: synchronization lock to prevent I/O race conditions + * @irq_mask: I/O bits affected by interrupts + * @flow_mask: IRQ flow type mask for the respective I/O bits + * @base: base port address of the GPIO device + * @irq: Interrupt line number + */ +struct ws16c48_gpio { + struct gpio_chip chip; + unsigned char io_state[6]; + unsigned char out_state[6]; + spinlock_t lock; + unsigned long irq_mask; + unsigned long flow_mask; + unsigned base; + unsigned irq; +}; + +static int ws16c48_gpio_get_direction(struct gpio_chip *chip, unsigned offset) +{ + struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip); + const unsigned port = offset / 8; + const unsigned mask = BIT(offset % 8); + + return !!(ws16c48gpio->io_state[port] & mask); +} + +static int ws16c48_gpio_direction_input(struct gpio_chip *chip, unsigned offset) +{ + struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip); + const unsigned port = offset / 8; + const unsigned mask = BIT(offset % 8); + unsigned long flags; + + spin_lock_irqsave(&ws16c48gpio->lock, flags); + + ws16c48gpio->io_state[port] |= mask; + ws16c48gpio->out_state[port] &= ~mask; + outb(ws16c48gpio->out_state[port], ws16c48gpio->base + port); + + spin_unlock_irqrestore(&ws16c48gpio->lock, flags); + + return 0; +} + +static int ws16c48_gpio_direction_output(struct gpio_chip *chip, + unsigned offset, int value) +{ + struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip); + const unsigned port = offset / 8; + const unsigned mask = BIT(offset % 8); + unsigned long flags; + + spin_lock_irqsave(&ws16c48gpio->lock, flags); + + ws16c48gpio->io_state[port] &= ~mask; + if (value) + ws16c48gpio->out_state[port] |= mask; + else + ws16c48gpio->out_state[port] &= ~mask; + outb(ws16c48gpio->out_state[port], ws16c48gpio->base + port); + + spin_unlock_irqrestore(&ws16c48gpio->lock, flags); + + return 0; +} + +static int ws16c48_gpio_get(struct gpio_chip *chip, unsigned offset) +{ + struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip); + const unsigned port = offset / 8; + const unsigned mask = BIT(offset % 8); + unsigned long flags; + unsigned port_state; + + spin_lock_irqsave(&ws16c48gpio->lock, flags); + + /* ensure that GPIO is set for input */ + if (!(ws16c48gpio->io_state[port] & mask)) { + spin_unlock_irqrestore(&ws16c48gpio->lock, flags); + return -EINVAL; + } + + port_state = inb(ws16c48gpio->base + port); + + spin_unlock_irqrestore(&ws16c48gpio->lock, flags); + + return !!(port_state & mask); +} + +static void ws16c48_gpio_set(struct gpio_chip *chip, unsigned offset, int value) +{ + struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip); + const unsigned port = offset / 8; + const unsigned mask = BIT(offset % 8); + unsigned long flags; + + spin_lock_irqsave(&ws16c48gpio->lock, flags); + + /* ensure that GPIO is set for output */ + if (ws16c48gpio->io_state[port] & mask) { + spin_unlock_irqrestore(&ws16c48gpio->lock, flags); + return; + } + + if (value) + ws16c48gpio->out_state[port] |= mask; + else + ws16c48gpio->out_state[port] &= ~mask; + outb(ws16c48gpio->out_state[port], ws16c48gpio->base + port); + + spin_unlock_irqrestore(&ws16c48gpio->lock, flags); +} + +static void ws16c48_irq_ack(struct irq_data *data) +{ + struct gpio_chip *chip = irq_data_get_irq_chip_data(data); + struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip); + const unsigned long offset = irqd_to_hwirq(data); + const unsigned port = offset / 8; + const unsigned mask = BIT(offset % 8); + unsigned long flags; + unsigned port_state; + + /* only the first 3 ports support interrupts */ + if (port > 2) + return; + + spin_lock_irqsave(&ws16c48gpio->lock, flags); + + port_state = ws16c48gpio->irq_mask >> (8*port); + + outb(0x80, ws16c48gpio->base + 7); + outb(port_state & ~mask, ws16c48gpio->base + 8 + port); + outb(port_state | mask, ws16c48gpio->base + 8 + port); + outb(0xC0, ws16c48gpio->base + 7); + + spin_unlock_irqrestore(&ws16c48gpio->lock, flags); +} + +static void ws16c48_irq_mask(struct irq_data *data) +{ + struct gpio_chip *chip = irq_data_get_irq_chip_data(data); + struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip); + const unsigned long offset = irqd_to_hwirq(data); + const unsigned long mask = BIT(offset); + const unsigned port = offset / 8; + unsigned long flags; + + /* only the first 3 ports support interrupts */ + if (port > 2) + return; + + spin_lock_irqsave(&ws16c48gpio->lock, flags); + + ws16c48gpio->irq_mask &= ~mask; + + outb(0x80, ws16c48gpio->base + 7); + outb(ws16c48gpio->irq_mask >> (8*port), ws16c48gpio->base + 8 + port); + outb(0xC0, ws16c48gpio->base + 7); + + spin_unlock_irqrestore(&ws16c48gpio->lock, flags); +} + +static void ws16c48_irq_unmask(struct irq_data *data) +{ + struct gpio_chip *chip = irq_data_get_irq_chip_data(data); + struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip); + const unsigned long offset = irqd_to_hwirq(data); + const unsigned long mask = BIT(offset); + const unsigned port = offset / 8; + unsigned long flags; + + /* only the first 3 ports support interrupts */ + if (port > 2) + return; + + spin_lock_irqsave(&ws16c48gpio->lock, flags); + + ws16c48gpio->irq_mask |= mask; + + outb(0x80, ws16c48gpio->base + 7); + outb(ws16c48gpio->irq_mask >> (8*port), ws16c48gpio->base + 8 + port); + outb(0xC0, ws16c48gpio->base + 7); + + spin_unlock_irqrestore(&ws16c48gpio->lock, flags); +} + +static int ws16c48_irq_set_type(struct irq_data *data, unsigned flow_type) +{ + struct gpio_chip *chip = irq_data_get_irq_chip_data(data); + struct ws16c48_gpio *const ws16c48gpio = gpiochip_get_data(chip); + const unsigned long offset = irqd_to_hwirq(data); + const unsigned long mask = BIT(offset); + const unsigned port = offset / 8; + unsigned long flags; + + /* only the first 3 ports support interrupts */ + if (port > 2) + return -EINVAL; + + spin_lock_irqsave(&ws16c48gpio->lock, flags); + + switch (flow_type) { + case IRQ_TYPE_NONE: + break; + case IRQ_TYPE_EDGE_RISING: + ws16c48gpio->flow_mask |= mask; + break; + case IRQ_TYPE_EDGE_FALLING: + ws16c48gpio->flow_mask &= ~mask; + break; + default: + spin_unlock_irqrestore(&ws16c48gpio->lock, flags); + return -EINVAL; + } + + outb(0x40, ws16c48gpio->base + 7); + outb(ws16c48gpio->flow_mask >> (8*port), ws16c48gpio->base + 8 + port); + outb(0xC0, ws16c48gpio->base + 7); + + spin_unlock_irqrestore(&ws16c48gpio->lock, flags); + + return 0; +} + +static struct irq_chip ws16c48_irqchip = { + .name = "ws16c48", + .irq_ack = ws16c48_irq_ack, + .irq_mask = ws16c48_irq_mask, + .irq_unmask = ws16c48_irq_unmask, + .irq_set_type = ws16c48_irq_set_type +}; + +static irqreturn_t ws16c48_irq_handler(int irq, void *dev_id) +{ + struct ws16c48_gpio *const ws16c48gpio = dev_id; + struct gpio_chip *const chip = &ws16c48gpio->chip; + unsigned long int_pending; + unsigned long port; + unsigned long int_id; + unsigned long gpio; + + int_pending = inb(ws16c48gpio->base + 6) & 0x7; + if (!int_pending) + return IRQ_NONE; + + /* loop until all pending interrupts are handled */ + do { + for_each_set_bit(port, &int_pending, 3) { + int_id = inb(ws16c48gpio->base + 8 + port); + for_each_set_bit(gpio, &int_id, 8) + generic_handle_irq(irq_find_mapping( + chip->irqdomain, gpio + 8*port)); + } + + int_pending = inb(ws16c48gpio->base + 6) & 0x7; + } while (int_pending); + + return IRQ_HANDLED; +} + +static int __init ws16c48_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct ws16c48_gpio *ws16c48gpio; + const unsigned base = ws16c48_base; + const unsigned extent = 16; + const char *const name = dev_name(dev); + int err; + const unsigned irq = ws16c48_irq; + + ws16c48gpio = devm_kzalloc(dev, sizeof(*ws16c48gpio), GFP_KERNEL); + if (!ws16c48gpio) + return -ENOMEM; + + if (!devm_request_region(dev, base, extent, name)) { + dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n", + base, base + extent); + return -EBUSY; + } + + ws16c48gpio->chip.label = name; + ws16c48gpio->chip.parent = dev; + ws16c48gpio->chip.owner = THIS_MODULE; + ws16c48gpio->chip.base = -1; + ws16c48gpio->chip.ngpio = 48; + ws16c48gpio->chip.get_direction = ws16c48_gpio_get_direction; + ws16c48gpio->chip.direction_input = ws16c48_gpio_direction_input; + ws16c48gpio->chip.direction_output = ws16c48_gpio_direction_output; + ws16c48gpio->chip.get = ws16c48_gpio_get; + ws16c48gpio->chip.set = ws16c48_gpio_set; + ws16c48gpio->base = base; + ws16c48gpio->irq = irq; + + spin_lock_init(&ws16c48gpio->lock); + + dev_set_drvdata(dev, ws16c48gpio); + + err = gpiochip_add_data(&ws16c48gpio->chip, ws16c48gpio); + if (err) { + dev_err(dev, "GPIO registering failed (%d)\n", err); + return err; + } + + /* Disable IRQ by default */ + outb(0x80, base + 7); + outb(0, base + 8); + outb(0, base + 9); + outb(0, base + 10); + outb(0xC0, base + 7); + + err = gpiochip_irqchip_add(&ws16c48gpio->chip, &ws16c48_irqchip, 0, + handle_edge_irq, IRQ_TYPE_NONE); + if (err) { + dev_err(dev, "Could not add irqchip (%d)\n", err); + goto err_gpiochip_remove; + } + + err = request_irq(irq, ws16c48_irq_handler, IRQF_SHARED, name, + ws16c48gpio); + if (err) { + dev_err(dev, "IRQ handler registering failed (%d)\n", err); + goto err_gpiochip_remove; + } + + return 0; + +err_gpiochip_remove: + gpiochip_remove(&ws16c48gpio->chip); + return err; +} + +static int ws16c48_remove(struct platform_device *pdev) +{ + struct ws16c48_gpio *const ws16c48gpio = platform_get_drvdata(pdev); + + free_irq(ws16c48gpio->irq, ws16c48gpio); + gpiochip_remove(&ws16c48gpio->chip); + + return 0; +} + +static struct platform_device *ws16c48_device; + +static struct platform_driver ws16c48_driver = { + .driver = { + .name = "ws16c48" + }, + .remove = ws16c48_remove +}; + +static void __exit ws16c48_exit(void) +{ + platform_device_unregister(ws16c48_device); + platform_driver_unregister(&ws16c48_driver); +} + +static int __init ws16c48_init(void) +{ + int err; + + ws16c48_device = platform_device_alloc(ws16c48_driver.driver.name, -1); + if (!ws16c48_device) + return -ENOMEM; + + err = platform_device_add(ws16c48_device); + if (err) + goto err_platform_device; + + err = platform_driver_probe(&ws16c48_driver, ws16c48_probe); + if (err) + goto err_platform_driver; + + return 0; + +err_platform_driver: + platform_device_del(ws16c48_device); +err_platform_device: + platform_device_put(ws16c48_device); + return err; +} + +module_init(ws16c48_init); +module_exit(ws16c48_exit); + +MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>"); +MODULE_DESCRIPTION("WinSystems WS16C48 GPIO driver"); +MODULE_LICENSE("GPL v2"); |