diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2014-04-03 16:44:15 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-04-03 16:44:15 -0700 |
commit | 154d6f18a48e00dec2dc84a96914fe1a24669577 (patch) | |
tree | 7b92ac64a00eb173af396752f3bfc72c9eba615c /drivers/gpio/gpio-zevio.c | |
parent | 76ca7d1cca761bb9712dfcad9a27d70b520874ae (diff) | |
parent | b22978fc33dec72e5f8e17f90eb63ea9137aafd5 (diff) |
Merge tag 'gpio-v3.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio
Pull bulk of gpio updates from Linus Walleij:
"A pretty big chunk of changes this time, but it has all been on
rotation in linux-next and had some testing. Of course there will be
some amount of fixes on top...
- Merged in a branch of irqchip changes from Thomas Gleixner: we need
to have new callbacks from the irqchip to determine if the GPIO
line will be eligible for IRQs, and this callback must be able to
say "no". After some thinking I got the branch from tglx and have
switched all current users over to use this.
- Based on tglx patches, we have added some generic irqchip helpers
in the gpiolib core. These will help centralize code when GPIO
drivers have simple chained/cascaded IRQs. Drivers will still
define their irqchip vtables, but the gpiolib core will take care
of irqdomain set-up, mapping from local offsets to Linux irqs, and
reserve resources by marking the GPIO lines for IRQs.
- Initially the PL061 and Nomadik GPIO/pin control drivers have been
switched over to use the new gpiochip-to-irqchip infrastructure
with more drivers expected for the next kernel cycle. The
factoring of just two drivers still makes it worth it so it is
already a win.
- A new driver for the Synopsys DesignWare APB GPIO block.
- Modify the DaVinci GPIO driver to be reusable also for the new TI
Keystone architecture.
- A new driver for the LSI ZEVIO SoCs.
- Delete the obsolte tnetv107x driver.
- Some incremental work on GPIO descriptors: have
gpiod_direction_output() use a logical level, respecting assertion
polarity through ACTIVE_LOW flags, adding gpiod_direction_output_raw()
for the case where you want to set that very value. Add
gpiochip_get_desc() to fetch a GPIO descriptor from a specific
offset on a certain chip inside driver code.
- Switch ACPI GPIO code over to using gpiochip_get_desc() and get rid
of gpio_to_desc().
- The ACPI GPIO event handling code has been reworked after
encountering an actual real life implementation.
- Support for ACPI GPIO operation regions.
- Generic GPIO chips can now be assigned labels/names from platform
data.
- We now clamp values returned from GPIO drivers to the boolean [0,1]
range.
- Some improved documentation on how to use the polarity flag was
added.
- a large slew of incremental driver updates and non-critical fixes.
Some targeted for stable"
* tag 'gpio-v3.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (80 commits)
gpio: rcar: Add helper variable dev = &pdev->dev
gpio-lynxpoint: force gpio_get() to return "1" and "0" only
gpio: unmap gpio irqs properly
pch_gpio: set value before enabling output direction
gpio: moxart: Actually set output state in moxart_gpio_direction_output()
gpio: moxart: Avoid forward declaration
gpio: mxs: Allow for recursive enable_irq_wake() call
gpio: samsung: Add missing "break" statement
gpio: twl4030: Remove redundant assignment
gpio: dwapb: correct gpio-cells in binding document
gpio: iop: fix devm_ioremap_resource() return value checking
pinctrl: coh901: convert driver to use gpiolib irqchip
pinctrl: nomadik: convert driver to use gpiolib irqchip
gpio: pl061: convert driver to use gpiolib irqchip
gpio: add IRQ chip helpers in gpiolib
pinctrl: nomadik: factor in platform data container
pinctrl: nomadik: rename secondary to latent
gpio: Driver for SYSCON-based GPIOs
gpio: generic: Use platform_device_id->driver_data field for driver flags
pinctrl: coh901: move irq line locking to resource callbacks
...
Diffstat (limited to 'drivers/gpio/gpio-zevio.c')
-rw-r--r-- | drivers/gpio/gpio-zevio.c | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-zevio.c b/drivers/gpio/gpio-zevio.c new file mode 100644 index 000000000000..9bf5034b6cdb --- /dev/null +++ b/drivers/gpio/gpio-zevio.c @@ -0,0 +1,220 @@ +/* + * GPIO controller in LSI ZEVIO SoCs. + * + * Author: Fabian Vogt <fabian@ritter-vogt.de> + * + * 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. + */ + +#include <linux/spinlock.h> +#include <linux/errno.h> +#include <linux/module.h> +#include <linux/bitops.h> +#include <linux/io.h> +#include <linux/of_device.h> +#include <linux/of_gpio.h> +#include <linux/slab.h> +#include <linux/gpio.h> + +/* + * Memory layout: + * This chip has four gpio sections, each controls 8 GPIOs. + * Bit 0 in section 0 is GPIO 0, bit 2 in section 1 is GPIO 10. + * Disclaimer: Reverse engineered! + * For more information refer to: + * http://hackspire.unsads.com/wiki/index.php/Memory-mapped_I/O_ports#90000000_-_General_Purpose_I.2FO_.28GPIO.29 + * + * 0x00-0x3F: Section 0 + * +0x00: Masked interrupt status (read-only) + * +0x04: R: Interrupt status W: Reset interrupt status + * +0x08: R: Interrupt mask W: Mask interrupt + * +0x0C: W: Unmask interrupt (write-only) + * +0x10: Direction: I/O=1/0 + * +0x14: Output + * +0x18: Input (read-only) + * +0x20: R: Level interrupt W: Set as level interrupt + * 0x40-0x7F: Section 1 + * 0x80-0xBF: Section 2 + * 0xC0-0xFF: Section 3 + */ + +#define ZEVIO_GPIO_SECTION_SIZE 0x40 + +/* Offsets to various registers */ +#define ZEVIO_GPIO_INT_MASKED_STATUS 0x00 +#define ZEVIO_GPIO_INT_STATUS 0x04 +#define ZEVIO_GPIO_INT_UNMASK 0x08 +#define ZEVIO_GPIO_INT_MASK 0x0C +#define ZEVIO_GPIO_DIRECTION 0x10 +#define ZEVIO_GPIO_OUTPUT 0x14 +#define ZEVIO_GPIO_INPUT 0x18 +#define ZEVIO_GPIO_INT_STICKY 0x20 + +#define to_zevio_gpio(chip) container_of(to_of_mm_gpio_chip(chip), \ + struct zevio_gpio, chip) + +/* Bit number of GPIO in its section */ +#define ZEVIO_GPIO_BIT(gpio) (gpio&7) + +struct zevio_gpio { + spinlock_t lock; + struct of_mm_gpio_chip chip; +}; + +static inline u32 zevio_gpio_port_get(struct zevio_gpio *c, unsigned pin, + unsigned port_offset) +{ + unsigned section_offset = ((pin >> 3) & 3)*ZEVIO_GPIO_SECTION_SIZE; + return readl(IOMEM(c->chip.regs + section_offset + port_offset)); +} + +static inline void zevio_gpio_port_set(struct zevio_gpio *c, unsigned pin, + unsigned port_offset, u32 val) +{ + unsigned section_offset = ((pin >> 3) & 3)*ZEVIO_GPIO_SECTION_SIZE; + writel(val, IOMEM(c->chip.regs + section_offset + port_offset)); +} + +/* Functions for struct gpio_chip */ +static int zevio_gpio_get(struct gpio_chip *chip, unsigned pin) +{ + struct zevio_gpio *controller = to_zevio_gpio(chip); + + /* Only reading allowed, so no spinlock needed */ + u32 val = zevio_gpio_port_get(controller, pin, ZEVIO_GPIO_INPUT); + + return (val >> ZEVIO_GPIO_BIT(pin)) & 0x1; +} + +static void zevio_gpio_set(struct gpio_chip *chip, unsigned pin, int value) +{ + struct zevio_gpio *controller = to_zevio_gpio(chip); + u32 val; + + spin_lock(&controller->lock); + val = zevio_gpio_port_get(controller, pin, ZEVIO_GPIO_OUTPUT); + if (value) + val |= BIT(ZEVIO_GPIO_BIT(pin)); + else + val &= ~BIT(ZEVIO_GPIO_BIT(pin)); + + zevio_gpio_port_set(controller, pin, ZEVIO_GPIO_OUTPUT, val); + spin_unlock(&controller->lock); +} + +static int zevio_gpio_direction_input(struct gpio_chip *chip, unsigned pin) +{ + struct zevio_gpio *controller = to_zevio_gpio(chip); + u32 val; + + spin_lock(&controller->lock); + + val = zevio_gpio_port_get(controller, pin, ZEVIO_GPIO_DIRECTION); + val |= BIT(ZEVIO_GPIO_BIT(pin)); + zevio_gpio_port_set(controller, pin, ZEVIO_GPIO_DIRECTION, val); + + spin_unlock(&controller->lock); + + return 0; +} + +static int zevio_gpio_direction_output(struct gpio_chip *chip, + unsigned pin, int value) +{ + struct zevio_gpio *controller = to_zevio_gpio(chip); + u32 val; + + spin_lock(&controller->lock); + val = zevio_gpio_port_get(controller, pin, ZEVIO_GPIO_OUTPUT); + if (value) + val |= BIT(ZEVIO_GPIO_BIT(pin)); + else + val &= ~BIT(ZEVIO_GPIO_BIT(pin)); + + zevio_gpio_port_set(controller, pin, ZEVIO_GPIO_OUTPUT, val); + val = zevio_gpio_port_get(controller, pin, ZEVIO_GPIO_DIRECTION); + val &= ~BIT(ZEVIO_GPIO_BIT(pin)); + zevio_gpio_port_set(controller, pin, ZEVIO_GPIO_DIRECTION, val); + + spin_unlock(&controller->lock); + + return 0; +} + +static int zevio_gpio_to_irq(struct gpio_chip *chip, unsigned pin) +{ + /* + * TODO: Implement IRQs. + * Not implemented yet due to weird lockups + */ + + return -ENXIO; +} + +static struct gpio_chip zevio_gpio_chip = { + .direction_input = zevio_gpio_direction_input, + .direction_output = zevio_gpio_direction_output, + .set = zevio_gpio_set, + .get = zevio_gpio_get, + .to_irq = zevio_gpio_to_irq, + .base = 0, + .owner = THIS_MODULE, + .ngpio = 32, + .of_gpio_n_cells = 2, +}; + +/* Initialization */ +static int zevio_gpio_probe(struct platform_device *pdev) +{ + struct zevio_gpio *controller; + int status, i; + + controller = devm_kzalloc(&pdev->dev, sizeof(*controller), GFP_KERNEL); + if (!controller) { + dev_err(&pdev->dev, "not enough free memory\n"); + return -ENOMEM; + } + + /* Copy our reference */ + controller->chip.gc = zevio_gpio_chip; + controller->chip.gc.dev = &pdev->dev; + + status = of_mm_gpiochip_add(pdev->dev.of_node, &(controller->chip)); + if (status) { + dev_err(&pdev->dev, "failed to add gpiochip: %d\n", status); + return status; + } + + spin_lock_init(&controller->lock); + + /* Disable interrupts, they only cause errors */ + for (i = 0; i < controller->chip.gc.ngpio; i += 8) + zevio_gpio_port_set(controller, i, ZEVIO_GPIO_INT_MASK, 0xFF); + + dev_dbg(controller->chip.gc.dev, "ZEVIO GPIO controller set up!\n"); + + return 0; +} + +static struct of_device_id zevio_gpio_of_match[] = { + { .compatible = "lsi,zevio-gpio", }, + { }, +}; + +MODULE_DEVICE_TABLE(of, zevio_gpio_of_match); + +static struct platform_driver zevio_gpio_driver = { + .driver = { + .name = "gpio-zevio", + .owner = THIS_MODULE, + .of_match_table = of_match_ptr(zevio_gpio_of_match), + }, + .probe = zevio_gpio_probe, +}; +module_platform_driver(zevio_gpio_driver); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Fabian Vogt <fabian@ritter-vogt.de>"); +MODULE_DESCRIPTION("LSI ZEVIO SoC GPIO driver"); |