diff options
| -rw-r--r-- | drivers/gpio/Kconfig | 12 | ||||
| -rw-r--r-- | drivers/gpio/Makefile | 1 | ||||
| -rw-r--r-- | drivers/gpio/gpio-kempld.c | 225 |
3 files changed, 238 insertions, 0 deletions
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index 02db4eafa9df..4b7ba53e96db 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -691,6 +691,18 @@ config GPIO_UCB1400 This enables support for the Philips UCB1400 GPIO pins. The UCB1400 is an AC97 audio codec. +comment "LPC GPIO expanders:" + +config GPIO_KEMPLD + tristate "Kontron ETX / COMexpress GPIO" + depends on MFD_KEMPLD + help + This enables support for the PLD GPIO interface on some Kontron ETX + and COMexpress (ETXexpress) modules. + + This driver can also be built as a module. If so, the module will be + called gpio-kempld. + comment "MODULbus GPIO expanders:" config GPIO_JANZ_TTL diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index fa97bf8698ed..156fd283945c 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -29,6 +29,7 @@ obj-$(CONFIG_GPIO_GRGPIO) += gpio-grgpio.o obj-$(CONFIG_GPIO_ICH) += gpio-ich.o obj-$(CONFIG_GPIO_IT8761E) += gpio-it8761e.o obj-$(CONFIG_GPIO_JANZ_TTL) += gpio-janz-ttl.o +obj-$(CONFIG_GPIO_KEMPLD) += gpio-kempld.o obj-$(CONFIG_ARCH_KS8695) += gpio-ks8695.o obj-$(CONFIG_GPIO_LANGWELL) += gpio-langwell.o obj-$(CONFIG_ARCH_LPC32XX) += gpio-lpc32xx.o diff --git a/drivers/gpio/gpio-kempld.c b/drivers/gpio/gpio-kempld.c new file mode 100644 index 000000000000..1bdc3a2e40dc --- /dev/null +++ b/drivers/gpio/gpio-kempld.c @@ -0,0 +1,225 @@ +/* + * Kontron PLD GPIO driver + * + * Copyright (c) 2010-2013 Kontron Europe GmbH + * Author: Michael Brunner <michael.brunner@kontron.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License 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/init.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/bitops.h> +#include <linux/errno.h> +#include <linux/platform_device.h> +#include <linux/gpio.h> +#include <linux/mfd/kempld.h> + +#define KEMPLD_GPIO_MAX_NUM 16 +#define KEMPLD_GPIO_MASK(x) (1 << ((x) % 8)) +#define KEMPLD_GPIO_DIR_NUM(x) (0x40 + (x) / 8) +#define KEMPLD_GPIO_LVL_NUM(x) (0x42 + (x) / 8) +#define KEMPLD_GPIO_EVT_LVL_EDGE 0x46 +#define KEMPLD_GPIO_IEN 0x4A + +struct kempld_gpio_data { + struct gpio_chip chip; + struct kempld_device_data *pld; +}; + +/* + * Set or clear GPIO bit + * kempld_get_mutex must be called prior to calling this function. + */ +static void kempld_gpio_bitop(struct kempld_device_data *pld, + u8 reg, u8 bit, u8 val) +{ + u8 status; + + status = kempld_read8(pld, reg); + if (val) + status |= (1 << bit); + else + status &= ~(1 << bit); + kempld_write8(pld, reg, status); +} + +static int kempld_gpio_get_bit(struct kempld_device_data *pld, u8 reg, u8 bit) +{ + u8 status; + + kempld_get_mutex(pld); + status = kempld_read8(pld, reg); + kempld_release_mutex(pld); + + return !!(status & (1 << bit)); +} + +static int kempld_gpio_get(struct gpio_chip *chip, unsigned offset) +{ + struct kempld_gpio_data *gpio + = container_of(chip, struct kempld_gpio_data, chip); + struct kempld_device_data *pld = gpio->pld; + + return kempld_gpio_get_bit(pld, KEMPLD_GPIO_LVL_NUM(offset), + KEMPLD_GPIO_MASK(offset)); +} + +static void kempld_gpio_set(struct gpio_chip *chip, unsigned offset, int value) +{ + struct kempld_gpio_data *gpio + = container_of(chip, struct kempld_gpio_data, chip); + struct kempld_device_data *pld = gpio->pld; + + kempld_get_mutex(pld); + kempld_gpio_bitop(pld, KEMPLD_GPIO_LVL_NUM(offset), + KEMPLD_GPIO_MASK(offset), value); + kempld_release_mutex(pld); +} + +static int kempld_gpio_direction_input(struct gpio_chip *chip, unsigned offset) +{ + struct kempld_gpio_data *gpio + = container_of(chip, struct kempld_gpio_data, chip); + struct kempld_device_data *pld = gpio->pld; + + kempld_get_mutex(pld); + kempld_gpio_bitop(pld, KEMPLD_GPIO_DIR_NUM(offset), + KEMPLD_GPIO_MASK(offset), 0); + kempld_release_mutex(pld); + + return 0; +} + +static int kempld_gpio_direction_output(struct gpio_chip *chip, unsigned offset, + int value) +{ + struct kempld_gpio_data *gpio + = container_of(chip, struct kempld_gpio_data, chip); + struct kempld_device_data *pld = gpio->pld; + + kempld_get_mutex(pld); + kempld_gpio_bitop(pld, KEMPLD_GPIO_LVL_NUM(offset), + KEMPLD_GPIO_MASK(offset), value); + kempld_gpio_bitop(pld, KEMPLD_GPIO_DIR_NUM(offset), + KEMPLD_GPIO_MASK(offset), 1); + kempld_release_mutex(pld); + + return 0; +} + +static int kempld_gpio_get_direction(struct gpio_chip *chip, unsigned offset) +{ + struct kempld_gpio_data *gpio + = container_of(chip, struct kempld_gpio_data, chip); + struct kempld_device_data *pld = gpio->pld; + + return kempld_gpio_get_bit(pld, KEMPLD_GPIO_DIR_NUM(offset), + KEMPLD_GPIO_MASK(offset)); +} + +static int kempld_gpio_pincount(struct kempld_device_data *pld) +{ + u16 evt, evt_back; + + kempld_get_mutex(pld); + + /* Backup event register as it might be already initialized */ + evt_back = kempld_read16(pld, KEMPLD_GPIO_EVT_LVL_EDGE); + /* Clear event register */ + kempld_write16(pld, KEMPLD_GPIO_EVT_LVL_EDGE, 0x0000); + /* Read back event register */ + evt = kempld_read16(pld, KEMPLD_GPIO_EVT_LVL_EDGE); + /* Restore event register */ + kempld_write16(pld, KEMPLD_GPIO_EVT_LVL_EDGE, evt_back); + + kempld_release_mutex(pld); + + return evt ? __ffs(evt) : 16; +} + +static int kempld_gpio_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct kempld_device_data *pld = dev_get_drvdata(dev->parent); + struct kempld_platform_data *pdata = pld->dev->platform_data; + struct kempld_gpio_data *gpio; + struct gpio_chip *chip; + int ret; + + if (pld->info.spec_major < 2) { + dev_err(dev, + "Driver only supports GPIO devices compatible to PLD spec. rev. 2.0 or higher\n"); + return -ENODEV; + } + + gpio = devm_kzalloc(dev, sizeof(*gpio), GFP_KERNEL); + if (gpio == NULL) + return -ENOMEM; + + gpio->pld = pld; + + platform_set_drvdata(pdev, gpio); + + chip = &gpio->chip; + chip->label = "gpio-kempld"; + chip->owner = THIS_MODULE; + chip->dev = dev; + chip->can_sleep = 1; + if (pdata && pdata->gpio_base) + chip->base = pdata->gpio_base; + else + chip->base = -1; + chip->direction_input = kempld_gpio_direction_input; + chip->direction_output = kempld_gpio_direction_output; + chip->get_direction = kempld_gpio_get_direction; + chip->get = kempld_gpio_get; + chip->set = kempld_gpio_set; + chip->ngpio = kempld_gpio_pincount(pld); + if (chip->ngpio == 0) { + dev_err(dev, "No GPIO pins detected\n"); + return -ENODEV; + } + + ret = gpiochip_add(chip); + if (ret) { + dev_err(dev, "Could not register GPIO chip\n"); + return ret; + } + + dev_info(dev, "GPIO functionality initialized with %d pins\n", + chip->ngpio); + + return 0; +} + +static int kempld_gpio_remove(struct platform_device *pdev) +{ + struct kempld_gpio_data *gpio = platform_get_drvdata(pdev); + + return gpiochip_remove(&gpio->chip); +} + +static struct platform_driver kempld_gpio_driver = { + .driver = { + .name = "gpio-kempld", + .owner = THIS_MODULE, + }, + .probe = kempld_gpio_probe, + .remove = kempld_gpio_remove, +}; + +module_platform_driver(kempld_gpio_driver); + +MODULE_DESCRIPTION("KEM PLD GPIO Driver"); +MODULE_AUTHOR("Michael Brunner <michael.brunner@kontron.com>"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:gpio-kempld"); |