forked from Minki/linux
gpio: Kontron PLD gpio driver
Add gpio support for the on-board PLD found on some Kontron embedded modules. Originally-from: Michael Brunner <michael.brunner@kontron.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Kevin Strasser <kevin.strasser@linux.intel.com> Acked-by: Darren Hart <dvhart@linux.intel.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Guenter Roeck
Linus Walleij
parent
a3d88c92a1
commit
d22fcde0b5
@ -691,6 +691,18 @@ config GPIO_UCB1400
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This enables support for the Philips UCB1400 GPIO pins.
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The UCB1400 is an AC97 audio codec.
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comment "LPC GPIO expanders:"
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config GPIO_KEMPLD
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tristate "Kontron ETX / COMexpress GPIO"
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depends on MFD_KEMPLD
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help
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This enables support for the PLD GPIO interface on some Kontron ETX
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and COMexpress (ETXexpress) modules.
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This driver can also be built as a module. If so, the module will be
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called gpio-kempld.
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comment "MODULbus GPIO expanders:"
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config GPIO_JANZ_TTL
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@ -29,6 +29,7 @@ obj-$(CONFIG_GPIO_GRGPIO) += gpio-grgpio.o
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obj-$(CONFIG_GPIO_ICH) += gpio-ich.o
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obj-$(CONFIG_GPIO_IT8761E) += gpio-it8761e.o
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obj-$(CONFIG_GPIO_JANZ_TTL) += gpio-janz-ttl.o
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obj-$(CONFIG_GPIO_KEMPLD) += gpio-kempld.o
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obj-$(CONFIG_ARCH_KS8695) += gpio-ks8695.o
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obj-$(CONFIG_GPIO_LANGWELL) += gpio-langwell.o
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obj-$(CONFIG_ARCH_LPC32XX) += gpio-lpc32xx.o
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225
drivers/gpio/gpio-kempld.c
Normal file
225
drivers/gpio/gpio-kempld.c
Normal file
@ -0,0 +1,225 @@
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/*
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* Kontron PLD GPIO driver
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*
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* Copyright (c) 2010-2013 Kontron Europe GmbH
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* Author: Michael Brunner <michael.brunner@kontron.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License 2 as published
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* by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/bitops.h>
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#include <linux/errno.h>
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#include <linux/platform_device.h>
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#include <linux/gpio.h>
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#include <linux/mfd/kempld.h>
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#define KEMPLD_GPIO_MAX_NUM 16
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#define KEMPLD_GPIO_MASK(x) (1 << ((x) % 8))
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#define KEMPLD_GPIO_DIR_NUM(x) (0x40 + (x) / 8)
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#define KEMPLD_GPIO_LVL_NUM(x) (0x42 + (x) / 8)
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#define KEMPLD_GPIO_EVT_LVL_EDGE 0x46
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#define KEMPLD_GPIO_IEN 0x4A
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struct kempld_gpio_data {
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struct gpio_chip chip;
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struct kempld_device_data *pld;
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};
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/*
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* Set or clear GPIO bit
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* kempld_get_mutex must be called prior to calling this function.
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*/
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static void kempld_gpio_bitop(struct kempld_device_data *pld,
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u8 reg, u8 bit, u8 val)
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{
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u8 status;
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status = kempld_read8(pld, reg);
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if (val)
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status |= (1 << bit);
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else
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status &= ~(1 << bit);
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kempld_write8(pld, reg, status);
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}
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static int kempld_gpio_get_bit(struct kempld_device_data *pld, u8 reg, u8 bit)
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{
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u8 status;
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kempld_get_mutex(pld);
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status = kempld_read8(pld, reg);
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kempld_release_mutex(pld);
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return !!(status & (1 << bit));
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}
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static int kempld_gpio_get(struct gpio_chip *chip, unsigned offset)
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{
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struct kempld_gpio_data *gpio
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= container_of(chip, struct kempld_gpio_data, chip);
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struct kempld_device_data *pld = gpio->pld;
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return kempld_gpio_get_bit(pld, KEMPLD_GPIO_LVL_NUM(offset),
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KEMPLD_GPIO_MASK(offset));
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}
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static void kempld_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
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{
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struct kempld_gpio_data *gpio
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= container_of(chip, struct kempld_gpio_data, chip);
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struct kempld_device_data *pld = gpio->pld;
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kempld_get_mutex(pld);
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kempld_gpio_bitop(pld, KEMPLD_GPIO_LVL_NUM(offset),
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KEMPLD_GPIO_MASK(offset), value);
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kempld_release_mutex(pld);
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}
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static int kempld_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
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{
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struct kempld_gpio_data *gpio
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= container_of(chip, struct kempld_gpio_data, chip);
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struct kempld_device_data *pld = gpio->pld;
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kempld_get_mutex(pld);
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kempld_gpio_bitop(pld, KEMPLD_GPIO_DIR_NUM(offset),
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KEMPLD_GPIO_MASK(offset), 0);
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kempld_release_mutex(pld);
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return 0;
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}
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static int kempld_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
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int value)
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{
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struct kempld_gpio_data *gpio
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= container_of(chip, struct kempld_gpio_data, chip);
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struct kempld_device_data *pld = gpio->pld;
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kempld_get_mutex(pld);
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kempld_gpio_bitop(pld, KEMPLD_GPIO_LVL_NUM(offset),
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KEMPLD_GPIO_MASK(offset), value);
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kempld_gpio_bitop(pld, KEMPLD_GPIO_DIR_NUM(offset),
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KEMPLD_GPIO_MASK(offset), 1);
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kempld_release_mutex(pld);
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return 0;
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}
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static int kempld_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
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{
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struct kempld_gpio_data *gpio
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= container_of(chip, struct kempld_gpio_data, chip);
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struct kempld_device_data *pld = gpio->pld;
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return kempld_gpio_get_bit(pld, KEMPLD_GPIO_DIR_NUM(offset),
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KEMPLD_GPIO_MASK(offset));
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}
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static int kempld_gpio_pincount(struct kempld_device_data *pld)
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{
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u16 evt, evt_back;
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kempld_get_mutex(pld);
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/* Backup event register as it might be already initialized */
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evt_back = kempld_read16(pld, KEMPLD_GPIO_EVT_LVL_EDGE);
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/* Clear event register */
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kempld_write16(pld, KEMPLD_GPIO_EVT_LVL_EDGE, 0x0000);
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/* Read back event register */
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evt = kempld_read16(pld, KEMPLD_GPIO_EVT_LVL_EDGE);
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/* Restore event register */
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kempld_write16(pld, KEMPLD_GPIO_EVT_LVL_EDGE, evt_back);
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kempld_release_mutex(pld);
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return evt ? __ffs(evt) : 16;
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}
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static int kempld_gpio_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct kempld_device_data *pld = dev_get_drvdata(dev->parent);
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struct kempld_platform_data *pdata = pld->dev->platform_data;
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struct kempld_gpio_data *gpio;
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struct gpio_chip *chip;
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int ret;
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if (pld->info.spec_major < 2) {
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dev_err(dev,
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"Driver only supports GPIO devices compatible to PLD spec. rev. 2.0 or higher\n");
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return -ENODEV;
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}
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gpio = devm_kzalloc(dev, sizeof(*gpio), GFP_KERNEL);
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if (gpio == NULL)
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return -ENOMEM;
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gpio->pld = pld;
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platform_set_drvdata(pdev, gpio);
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chip = &gpio->chip;
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chip->label = "gpio-kempld";
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chip->owner = THIS_MODULE;
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chip->dev = dev;
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chip->can_sleep = 1;
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if (pdata && pdata->gpio_base)
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chip->base = pdata->gpio_base;
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else
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chip->base = -1;
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chip->direction_input = kempld_gpio_direction_input;
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chip->direction_output = kempld_gpio_direction_output;
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chip->get_direction = kempld_gpio_get_direction;
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chip->get = kempld_gpio_get;
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chip->set = kempld_gpio_set;
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chip->ngpio = kempld_gpio_pincount(pld);
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if (chip->ngpio == 0) {
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dev_err(dev, "No GPIO pins detected\n");
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return -ENODEV;
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}
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ret = gpiochip_add(chip);
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if (ret) {
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dev_err(dev, "Could not register GPIO chip\n");
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return ret;
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}
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dev_info(dev, "GPIO functionality initialized with %d pins\n",
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chip->ngpio);
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return 0;
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}
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static int kempld_gpio_remove(struct platform_device *pdev)
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{
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struct kempld_gpio_data *gpio = platform_get_drvdata(pdev);
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return gpiochip_remove(&gpio->chip);
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}
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static struct platform_driver kempld_gpio_driver = {
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.driver = {
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.name = "gpio-kempld",
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.owner = THIS_MODULE,
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},
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.probe = kempld_gpio_probe,
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.remove = kempld_gpio_remove,
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};
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module_platform_driver(kempld_gpio_driver);
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MODULE_DESCRIPTION("KEM PLD GPIO Driver");
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MODULE_AUTHOR("Michael Brunner <michael.brunner@kontron.com>");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:gpio-kempld");
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