Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756739AbYJXVLy (ORCPT ); Fri, 24 Oct 2008 17:11:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754201AbYJXVLq (ORCPT ); Fri, 24 Oct 2008 17:11:46 -0400 Received: from outbound-wa4.frontbridge.com ([216.32.181.16]:14773 "EHLO WA4EHSOBE006.bigfish.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751985AbYJXVLp (ORCPT ); Fri, 24 Oct 2008 17:11:45 -0400 X-BigFish: VPS16(zz541L18c1Kc8kzzzzz2dh87il64h) X-Spam-TCS-SCL: 3:0 X-FB-DOMAIN-IP-MATCH: fail From: John Linn To: linux-kernel@vger.kernel.org CC: John Linn , Kiran Sutariya Subject: [PATCH] [powerpc] GPIO: Adding new Xilinx driver Date: Fri, 24 Oct 2008 14:11:38 -0700 X-Mailer: git-send-email 1.5.2.1 Message-ID: <20081024211138.38D477F0068@mail95-wa4.bigfish.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 9864 Lines: 300 This driver supports the Xilinx XPS GPIO IP core which has the typical GPIO features. Signed-off-by: Kiran Sutariya Signed-off-by: John Linn --- drivers/gpio/Kconfig | 8 ++ drivers/gpio/Makefile | 1 + drivers/gpio/xilinx_gpio.c | 240 ++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 249 insertions(+), 0 deletions(-) create mode 100644 drivers/gpio/xilinx_gpio.c diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index 7f2ee27..f6b0da8 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -65,6 +65,14 @@ config GPIO_SYSFS # put expanders in the right section, in alphabetical order +comment "Memory mapped GPIO expanders:" + +config GPIO_XILINX + bool "Xilinx GPIO support" + depends on OF + help + Say yes here to support the Xilinx FPGA GPIO device + comment "I2C GPIO expanders:" config GPIO_MAX732X diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index 6aafdeb..49ac64e 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -10,4 +10,5 @@ obj-$(CONFIG_GPIO_MCP23S08) += mcp23s08.o obj-$(CONFIG_GPIO_PCA953X) += pca953x.o obj-$(CONFIG_GPIO_PCF857X) += pcf857x.o obj-$(CONFIG_GPIO_TWL4030) += twl4030-gpio.o +obj-$(CONFIG_GPIO_XILINX) += xilinx_gpio.o obj-$(CONFIG_GPIO_BT8XX) += bt8xxgpio.o diff --git a/drivers/gpio/xilinx_gpio.c b/drivers/gpio/xilinx_gpio.c new file mode 100644 index 0000000..224d0d5 --- /dev/null +++ b/drivers/gpio/xilinx_gpio.c @@ -0,0 +1,240 @@ +/* + * Xilinx gpio driver + * + * 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 + +/* Register Offset Definitions */ +#define XGPIO_DATA_OFFSET (0x0) /* Data register */ +#define XGPIO_TRI_OFFSET (0x4) /* I/O direction register */ + +struct xgpio_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 */ +}; + +/** + * xgpio_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 xgpio_get(struct gpio_chip *gc, unsigned int gpio) +{ + struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc); + + return (in_be32(mm_gc->regs + XGPIO_DATA_OFFSET) >> gpio) & 1; +} + +/** + * xgpio_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 xgpio_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 xgpio_instance *chip = + container_of(mm_gc, struct xgpio_instance, mmchip); + + spin_lock_irqsave(&chip->gpio_lock, flags); + + /* Write to GPIO signal and set its direction to output */ + if (val) + chip->gpio_state |= 1 << gpio; + else + chip->gpio_state &= ~(1 << gpio); + out_be32(mm_gc->regs + XGPIO_DATA_OFFSET, chip->gpio_state); + + spin_unlock_irqrestore(&chip->gpio_lock, flags); +} + +/** + * xgpio_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 xgpio_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 xgpio_instance *chip = + container_of(mm_gc, struct xgpio_instance, mmchip); + + spin_lock_irqsave(&chip->gpio_lock, flags); + + /* Set the GPIO bit in shadow register and set direction as input */ + chip->gpio_dir |= (1 << gpio); + out_be32(mm_gc->regs + XGPIO_TRI_OFFSET, chip->gpio_dir); + + spin_unlock_irqrestore(&chip->gpio_lock, flags); + + return 0; +} + +/** + * xgpio_dir_out - Set the direction of the specified GPIO signal 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 xgpio_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 xgpio_instance *chip = + container_of(mm_gc, struct xgpio_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); + out_be32(mm_gc->regs + XGPIO_DATA_OFFSET, chip->gpio_state); + + /* Clear the GPIO bit in shadow register and set direction as output */ + chip->gpio_dir &= (~(1 << gpio)); + out_be32(mm_gc->regs + XGPIO_TRI_OFFSET, chip->gpio_dir); + + spin_unlock_irqrestore(&chip->gpio_lock, flags); + + return 0; +} + +/** + * xgpio_of_probe - Probe method for the GPIO device. + * @of_dev: pointer to OF device structure. + * @match: pointer to the structure used for matching a device. + * + * 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 xgpio_of_probe(struct of_device *ofdev, + const struct of_device_id *match) +{ + struct xgpio_instance *chip; + struct of_gpio_chip *ofchip; + int status = 0; + const u32 *tree_info; + + chip = kzalloc(sizeof(*chip), GFP_KERNEL); + if (!chip) + return -ENOMEM; + ofchip = &chip->mmchip.of_gc; + + /* Update GPIO state shadow register with default value */ + tree_info = of_get_property(ofdev->node, "xlnx,dout-default", NULL); + if (tree_info) + chip->gpio_state = *tree_info; + + /* Update GPIO direction shadow register with default value */ + chip->gpio_dir = 0xFFFFFFFF; /* By default, all pins are inputs */ + tree_info = of_get_property(ofdev->node, "xlnx,tri-default", NULL); + if (tree_info) + chip->gpio_dir = *tree_info; + + /* Check device node and parent device node for device width */ + ofchip->gc.ngpio = 32; /* By default assume full GPIO controller */ + tree_info = of_get_property(ofdev->node, "xlnx,gpio-width", NULL); + if (!tree_info) + tree_info = of_get_property(ofdev->node->parent, + "xlnx,gpio-width", NULL); + if (tree_info) + ofchip->gc.ngpio = *tree_info; + + spin_lock_init(&chip->gpio_lock); + + ofchip->gpio_cells = 2; + ofchip->gc.direction_input = xgpio_dir_in; + ofchip->gc.direction_output = xgpio_dir_out; + ofchip->gc.get = xgpio_get; + ofchip->gc.set = xgpio_set; + + /* Call the OF gpio helper to setup and register the GPIO device */ + status = of_mm_gpiochip_add(ofdev->node, &chip->mmchip); + if (status) { + kfree(chip); + dev_err(&ofdev->dev, "Error in probe function error value %d\n", + status); + return status; + } + + /* Finally, write the initial state to the device */ + out_be32(chip->mmchip.regs + XGPIO_DATA_OFFSET, chip->gpio_state); + out_be32(chip->mmchip.regs + XGPIO_TRI_OFFSET, chip->gpio_dir); + + dev_info(&ofdev->dev, "registered Xilinx GPIO controller\n"); + return 0; +} + +/** + * xgpio_of_remove - Remove method for the GPIO device. + * @of_dev: pointer to OF device structure. + * + * This function returns a negative error as we cannot unregister GPIO chips. + */ +static int __devexit xgpio_of_remove(struct of_device *ofdev) +{ + return -EBUSY; +} + +static struct of_device_id xgpio_of_match[] __devinitdata = { + { .compatible = "xlnx,xps-gpio-1.00.a", }, + { /* end of list */ }, +}; + +MODULE_DEVICE_TABLE(of, xgpio_of_match); + +static struct of_platform_driver xgpio_of_driver = { + .name = "xilinx_gpio", + .match_table = xgpio_of_match, + .probe = xgpio_of_probe, + .remove = __devexit_p(xgpio_of_remove), +}; + +static int __init xgpio_init(void) +{ + return of_register_platform_driver(&xgpio_of_driver); +} + +/* Make sure we get initialized before anyone else tries to use us */ +subsys_initcall(xgpio_init); +/* No exit call at the moment as we cannot unregister of GPIO chips */ + +MODULE_AUTHOR("Xilinx, Inc."); +MODULE_DESCRIPTION("Xilinx GPIO driver"); +MODULE_LICENSE("GPL"); -- 1.5.2.1 This email and any attachments are intended for the sole use of the named recipient(s) and contain(s) confidential information that may be proprietary, privileged or copyrighted under applicable law. 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