Revision 87b87a3fc0eec58d95e4216392f889a26439ad22 authored by Daniel Drake on 09 April 2012, 23:14:20 UTC, committed by Chris Ball on 21 April 2012, 00:44:25 UTC
Commit c79396c191bc19 ("mmc: sdhci: prevent card detection activity for non-removable cards") disables card detection where the cards are marked as non-removable. This makes sense, but the implementation detail of calling mmc_card_is_removable() causes some problems, because mmc_card_is_removable() is overloaded with CONFIG_MMC_UNSAFE_RESUME semantics. In the OLPC XO case, we need CONFIG_MMC_UNSAFE_RESUME because our root filesystem is stored on SD, but we also have external SD card slots where we want automatic card detection. Refine the check to only apply to hosts marked as MMC_CAP_NONREMOVABLE, which is defined to mean that the card is *really* nonremovable. This could be revisited in future if we find a way to improve CONFIG_MMC_UNSAFE_RESUME semantics. Signed-off-by: Daniel Drake <dsd@laptop.org> Acked-by: Chuanxiao Dong <chuanxiao.dong@intel.com> [stable@: please apply to 3.3-stable] Cc: stable <stable@vger.kernel.org> Signed-off-by: Chris Ball <cjb@laptop.org>
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gpio-xilinx.c
/*
* 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 <linux/init.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/of_platform.h>
#include <linux/of_gpio.h>
#include <linux/io.h>
#include <linux/gpio.h>
#include <linux/slab.h>
/* 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_save_regs - Set initial values of GPIO pins
* @mm_gc: pointer to memory mapped GPIO chip structure
*/
static void xgpio_save_regs(struct of_mm_gpio_chip *mm_gc)
{
struct xgpio_instance *chip =
container_of(mm_gc, struct xgpio_instance, mmchip);
out_be32(mm_gc->regs + XGPIO_DATA_OFFSET, chip->gpio_state);
out_be32(mm_gc->regs + XGPIO_TRI_OFFSET, chip->gpio_dir);
}
/**
* xgpio_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 xgpio_of_probe(struct device_node *np)
{
struct xgpio_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, "xlnx,dout-default", NULL);
if (tree_info)
chip->gpio_state = be32_to_cpup(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(np, "xlnx,tri-default", NULL);
if (tree_info)
chip->gpio_dir = be32_to_cpup(tree_info);
/* Check device node and parent device node for device width */
chip->mmchip.gc.ngpio = 32; /* By default assume full GPIO controller */
tree_info = of_get_property(np, "xlnx,gpio-width", NULL);
if (!tree_info)
tree_info = of_get_property(np->parent,
"xlnx,gpio-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 = xgpio_dir_in;
chip->mmchip.gc.direction_output = xgpio_dir_out;
chip->mmchip.gc.get = xgpio_get;
chip->mmchip.gc.set = xgpio_set;
chip->mmchip.save_regs = xgpio_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;
}
return 0;
}
static struct of_device_id xgpio_of_match[] __devinitdata = {
{ .compatible = "xlnx,xps-gpio-1.00.a", },
{ /* end of list */ },
};
static int __init xgpio_init(void)
{
struct device_node *np;
for_each_matching_node(np, xgpio_of_match)
xgpio_of_probe(np);
return 0;
}
/* 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");
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