Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754289Ab1BCH4u (ORCPT ); Thu, 3 Feb 2011 02:56:50 -0500 Received: from www.wytron.com.tw ([211.75.82.101]:48095 "EHLO www.wytron.com.tw" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753704Ab1BCH4t (ORCPT ); Thu, 3 Feb 2011 02:56:49 -0500 From: Thomas Chou To: Andrew Morton Cc: linux-kernel@vger.kernel.org, nios2-dev@sopc.et.ntust.edu.tw, Grant Likely , devicetree-discuss@lists.ozlabs.org, Thomas Chou Subject: [PATCH v2] gpio: add new Altera PIO driver Date: Thu, 3 Feb 2011 15:56:57 +0800 Message-Id: <1296719817-3007-1-git-send-email-thomas@wytron.com.tw> X-Mailer: git-send-email 1.7.3.5 In-Reply-To: <201101262237.p0QMb95f008734@imap1.linux-foundation.org> References: <201101262237.p0QMb95f008734@imap1.linux-foundation.org> X-SA-Exim-Connect-IP: 192.168.1.250 X-SA-Exim-Mail-From: thomas@wytron.com.tw X-SA-Exim-Scanned: No (on www.wytron.com.tw); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 9884 Lines: 304 This driver supports the Altera PIO core. Signed-off-by: Thomas Chou --- v2 change compatible vendor to uppercase, ALTR. add dts binding doc. .../devicetree/bindings/gpio/altera_gpio.txt | 7 + drivers/gpio/Kconfig | 6 + drivers/gpio/Makefile | 1 + drivers/gpio/altera_gpio.c | 233 ++++++++++++++++++++ 4 files changed, 247 insertions(+), 0 deletions(-) create mode 100644 Documentation/devicetree/bindings/gpio/altera_gpio.txt create mode 100644 drivers/gpio/altera_gpio.c diff --git a/Documentation/devicetree/bindings/gpio/altera_gpio.txt b/Documentation/devicetree/bindings/gpio/altera_gpio.txt new file mode 100644 index 0000000..5ab751a --- /dev/null +++ b/Documentation/devicetree/bindings/gpio/altera_gpio.txt @@ -0,0 +1,7 @@ +Altera GPIO + +Required properties: +- compatible : should be "ALTR,pio-1.0". +Optional properties: +- resetvalue : the reset value of the output port. +- width : the width of the port in number of bits. diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index 664660e..40271f0 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -70,6 +70,12 @@ config GPIO_MAX730X comment "Memory mapped GPIO expanders:" +config GPIO_ALTERA + bool "Altera GPIO" + depends on OF + help + Say yes here to support the Altera PIO device + config GPIO_BASIC_MMIO tristate "Basic memory-mapped GPIO controllers support" help diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index 3351cf8..ed11932 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -8,6 +8,7 @@ ccflags-$(CONFIG_DEBUG_GPIO) += -DDEBUG obj-$(CONFIG_GPIOLIB) += gpiolib.o +obj-$(CONFIG_GPIO_ALTERA) += altera_gpio.o obj-$(CONFIG_GPIO_ADP5520) += adp5520-gpio.o obj-$(CONFIG_GPIO_ADP5588) += adp5588-gpio.o obj-$(CONFIG_GPIO_BASIC_MMIO) += basic_mmio_gpio.o diff --git a/drivers/gpio/altera_gpio.c b/drivers/gpio/altera_gpio.c new file mode 100644 index 0000000..a173eb3 --- /dev/null +++ b/drivers/gpio/altera_gpio.c @@ -0,0 +1,233 @@ +/* + * Altera GPIO driver + * + * Copyright (C) 2011 Thomas Chou + * + * Based on Xilinx gpio driver, which is + * Copyright 2008 Xilinx, Inc. + * + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#define DRV_NAME "altera_gpio" + +/* Register Offset Definitions */ +#define ALTERA_GPIO_DATA_OFFSET 0x0 /* Data register */ +#define ALTERA_GPIO_DIR_OFFSET 0x4 /* I/O direction register */ + +struct altera_gpio_instance { + struct of_mm_gpio_chip mmchip; + u32 gpio_state; /* GPIO state shadow register */ + u32 gpio_dir; /* GPIO direction shadow register */ + spinlock_t gpio_lock; /* Lock used for synchronization */ +}; + +/* + * altera_gpio_get - Read the specified signal of the GPIO device. + * @gc: Pointer to gpio_chip device structure. + * @gpio: GPIO signal number. + * + * This function reads the specified signal of the GPIO device. It returns 0 if + * the signal clear, 1 if signal is set or negative value on error. + */ +static int altera_gpio_get(struct gpio_chip *gc, unsigned int gpio) +{ + struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc); + + return (readl(mm_gc->regs + ALTERA_GPIO_DATA_OFFSET) >> gpio) & 1; +} + +/* + * altera_gpio_set - Write the specified signal of the GPIO device. + * @gc: Pointer to gpio_chip device structure. + * @gpio: GPIO signal number. + * @val: Value to be written to specified signal. + * + * This function writes the specified value in to the specified signal of the + * GPIO device. + */ +static void altera_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val) +{ + unsigned long flags; + struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc); + struct altera_gpio_instance *chip = + container_of(mm_gc, struct altera_gpio_instance, mmchip); + + spin_lock_irqsave(&chip->gpio_lock, flags); + + /* Write to shadow register and output */ + if (val) + chip->gpio_state |= 1 << gpio; + else + chip->gpio_state &= ~(1 << gpio); + writel(chip->gpio_state, mm_gc->regs + ALTERA_GPIO_DATA_OFFSET); + + spin_unlock_irqrestore(&chip->gpio_lock, flags); +} + +/* + * altera_gpio_dir_in - Set the direction of the specified GPIO signal as input. + * @gc: Pointer to gpio_chip device structure. + * @gpio: GPIO signal number. + * + * This function sets the direction of specified GPIO signal as input. + * It returns 0 if direction of GPIO signals is set as input otherwise it + * returns negative error value. + */ +static int altera_gpio_dir_in(struct gpio_chip *gc, unsigned int gpio) +{ + unsigned long flags; + struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc); + struct altera_gpio_instance *chip = + container_of(mm_gc, struct altera_gpio_instance, mmchip); + + spin_lock_irqsave(&chip->gpio_lock, flags); + + /* Clear the GPIO bit in shadow register and set direction as input */ + chip->gpio_dir &= ~(1 << gpio); + writel(chip->gpio_dir, mm_gc->regs + ALTERA_GPIO_DIR_OFFSET); + + spin_unlock_irqrestore(&chip->gpio_lock, flags); + + return 0; +} + +/* + * altera_gpio_dir_out - Set the direction of the specified GPIO as output. + * @gc: Pointer to gpio_chip device structure. + * @gpio: GPIO signal number. + * @val: Value to be written to specified signal. + * + * This function sets the direction of specified GPIO signal as output. If all + * GPIO signals of GPIO chip is configured as input then it returns + * error otherwise it returns 0. + */ +static int altera_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val) +{ + unsigned long flags; + struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc); + struct altera_gpio_instance *chip = + container_of(mm_gc, struct altera_gpio_instance, mmchip); + + spin_lock_irqsave(&chip->gpio_lock, flags); + + /* Write state of GPIO signal */ + if (val) + chip->gpio_state |= 1 << gpio; + else + chip->gpio_state &= ~(1 << gpio); + writel(chip->gpio_state, mm_gc->regs + ALTERA_GPIO_DATA_OFFSET); + + /* Set the GPIO bit in shadow register and set direction as output */ + chip->gpio_dir |= (1 << gpio); + writel(chip->gpio_dir, mm_gc->regs + ALTERA_GPIO_DIR_OFFSET); + + spin_unlock_irqrestore(&chip->gpio_lock, flags); + + return 0; +} + +/* + * altera_gpio_save_regs - Set initial values of GPIO pins + * @mm_gc: pointer to memory mapped GPIO chip structure + */ +static void altera_gpio_save_regs(struct of_mm_gpio_chip *mm_gc) +{ + struct altera_gpio_instance *chip = + container_of(mm_gc, struct altera_gpio_instance, mmchip); + + writel(chip->gpio_state, mm_gc->regs + ALTERA_GPIO_DATA_OFFSET); + writel(chip->gpio_dir, mm_gc->regs + ALTERA_GPIO_DIR_OFFSET); +} + +/* + * altera_gpio_of_probe - Probe method for the GPIO device. + * @np: pointer to device tree node + * + * This function probes the GPIO device in the device tree. It initializes the + * driver data structure. It returns 0, if the driver is bound to the GPIO + * device, or a negative value if there is an error. + */ +static int __devinit altera_gpio_of_probe(struct device_node *np) +{ + struct altera_gpio_instance *chip; + int status = 0; + const u32 *tree_info; + + chip = kzalloc(sizeof(*chip), GFP_KERNEL); + if (!chip) + return -ENOMEM; + + /* Update GPIO state shadow register with default value */ + tree_info = of_get_property(np, "resetvalue", NULL); + if (tree_info) + chip->gpio_state = be32_to_cpup(tree_info); + + /* Update GPIO direction shadow register with default value */ + chip->gpio_dir = 0; /* By default, all pins are inputs */ + + /* Check device node for device width */ + chip->mmchip.gc.ngpio = 32; /* By default assume full GPIO controller */ + tree_info = of_get_property(np, "width", NULL); + if (tree_info) + chip->mmchip.gc.ngpio = be32_to_cpup(tree_info); + + spin_lock_init(&chip->gpio_lock); + + chip->mmchip.gc.direction_input = altera_gpio_dir_in; + chip->mmchip.gc.direction_output = altera_gpio_dir_out; + chip->mmchip.gc.get = altera_gpio_get; + chip->mmchip.gc.set = altera_gpio_set; + + chip->mmchip.save_regs = altera_gpio_save_regs; + + /* Call the OF gpio helper to setup and register the GPIO device */ + status = of_mm_gpiochip_add(np, &chip->mmchip); + if (status) { + kfree(chip); + pr_err("%s: error in probe function with status %d\n", + np->full_name, status); + return status; + } + pr_info(DRV_NAME ": %s: registered\n", np->full_name); + return 0; +} + +static struct of_device_id altera_gpio_of_match[] __devinitdata = { + { .compatible = "ALTR,pio-1.0", }, + {}, +}; + +static int __init altera_gpio_init(void) +{ + struct device_node *np; + + for_each_matching_node(np, altera_gpio_of_match) + altera_gpio_of_probe(np); + + return 0; +} + +/* Make sure we get initialized before anyone else tries to use us */ +subsys_initcall(altera_gpio_init); +/* No exit call at the moment as we cannot unregister of GPIO chips */ + +MODULE_DESCRIPTION("Altera GPIO driver"); +MODULE_AUTHOR("Thomas Chou "); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:" DRV_NAME); -- 1.7.3.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/