nouveau: off by one in nv50_gpio_location()

[net-next-2.6.git] / drivers / gpu / drm / nouveau / nv50_gpio.c

/*
 * Copyright 2010 Red Hat Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 *
 * Authors: Ben Skeggs
 */

#include "drmP.h"
#include "nouveau_drv.h"
#include "nouveau_hw.h"

static int
nv50_gpio_location(struct dcb_gpio_entry *gpio, uint32_t *reg, uint32_t *shift)
{
	const uint32_t nv50_gpio_reg[4] = { 0xe104, 0xe108, 0xe280, 0xe284 };

	if (gpio->line >= 32)
		return -EINVAL;

	*reg = nv50_gpio_reg[gpio->line >> 3];
	*shift = (gpio->line & 7) << 2;
	return 0;
}

int
nv50_gpio_get(struct drm_device *dev, enum dcb_gpio_tag tag)
{
	struct dcb_gpio_entry *gpio;
	uint32_t r, s, v;

	gpio = nouveau_bios_gpio_entry(dev, tag);
	if (!gpio)
		return -ENOENT;

	if (nv50_gpio_location(gpio, &r, &s))
		return -EINVAL;

	v = nv_rd32(dev, r) >> (s + 2);
	return ((v & 1) == (gpio->state[1] & 1));
}

int
nv50_gpio_set(struct drm_device *dev, enum dcb_gpio_tag tag, int state)
{
	struct dcb_gpio_entry *gpio;
	uint32_t r, s, v;

	gpio = nouveau_bios_gpio_entry(dev, tag);
	if (!gpio)
		return -ENOENT;

	if (nv50_gpio_location(gpio, &r, &s))
		return -EINVAL;

	v  = nv_rd32(dev, r) & ~(0x3 << s);
	v |= (gpio->state[state] ^ 2) << s;
	nv_wr32(dev, r, v);
	return 0;
}