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6417f03132
MODULE_SUPPORTED_DEVICE was added in pre-git era and never was implemented. We can safely remove it, because the kernel has grown to have many more reliable mechanisms to determine if device is supported or not. Signed-off-by: Leon Romanovsky <leonro@nvidia.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
270 lines
6.1 KiB
C
270 lines
6.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/* display7seg.c - Driver implementation for the 7-segment display
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* present on Sun Microsystems CP1400 and CP1500
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*
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* Copyright (c) 2000 Eric Brower (ebrower@usa.net)
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*/
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#include <linux/device.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/fs.h>
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#include <linux/errno.h>
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#include <linux/major.h>
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#include <linux/miscdevice.h>
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#include <linux/ioport.h> /* request_region */
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#include <linux/slab.h>
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#include <linux/mutex.h>
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#include <linux/of.h>
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#include <linux/of_device.h>
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#include <linux/atomic.h>
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#include <linux/uaccess.h> /* put_/get_user */
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#include <asm/io.h>
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#include <asm/display7seg.h>
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#define DRIVER_NAME "d7s"
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#define PFX DRIVER_NAME ": "
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static DEFINE_MUTEX(d7s_mutex);
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static int sol_compat = 0; /* Solaris compatibility mode */
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/* Solaris compatibility flag -
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* The Solaris implementation omits support for several
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* documented driver features (ref Sun doc 806-0180-03).
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* By default, this module supports the documented driver
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* abilities, rather than the Solaris implementation:
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*
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* 1) Device ALWAYS reverts to OBP-specified FLIPPED mode
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* upon closure of device or module unload.
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* 2) Device ioctls D7SIOCRD/D7SIOCWR honor toggling of
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* FLIP bit
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*
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* If you wish the device to operate as under Solaris,
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* omitting above features, set this parameter to non-zero.
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*/
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module_param(sol_compat, int, 0);
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MODULE_PARM_DESC(sol_compat,
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"Disables documented functionality omitted from Solaris driver");
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MODULE_AUTHOR("Eric Brower <ebrower@usa.net>");
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MODULE_DESCRIPTION("7-Segment Display driver for Sun Microsystems CP1400/1500");
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MODULE_LICENSE("GPL");
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struct d7s {
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void __iomem *regs;
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bool flipped;
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};
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struct d7s *d7s_device;
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/*
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* Register block address- see header for details
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* -----------------------------------------
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* | DP | ALARM | FLIP | 4 | 3 | 2 | 1 | 0 |
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* -----------------------------------------
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*
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* DP - Toggles decimal point on/off
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* ALARM - Toggles "Alarm" LED green/red
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* FLIP - Inverts display for upside-down mounted board
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* bits 0-4 - 7-segment display contents
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*/
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static atomic_t d7s_users = ATOMIC_INIT(0);
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static int d7s_open(struct inode *inode, struct file *f)
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{
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if (D7S_MINOR != iminor(inode))
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return -ENODEV;
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atomic_inc(&d7s_users);
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return 0;
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}
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static int d7s_release(struct inode *inode, struct file *f)
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{
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/* Reset flipped state to OBP default only if
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* no other users have the device open and we
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* are not operating in solaris-compat mode
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*/
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if (atomic_dec_and_test(&d7s_users) && !sol_compat) {
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struct d7s *p = d7s_device;
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u8 regval = 0;
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regval = readb(p->regs);
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if (p->flipped)
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regval |= D7S_FLIP;
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else
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regval &= ~D7S_FLIP;
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writeb(regval, p->regs);
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}
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return 0;
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}
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static long d7s_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
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{
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struct d7s *p = d7s_device;
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u8 regs = readb(p->regs);
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int error = 0;
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u8 ireg = 0;
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if (D7S_MINOR != iminor(file_inode(file)))
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return -ENODEV;
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mutex_lock(&d7s_mutex);
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switch (cmd) {
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case D7SIOCWR:
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/* assign device register values we mask-out D7S_FLIP
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* if in sol_compat mode
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*/
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if (get_user(ireg, (int __user *) arg)) {
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error = -EFAULT;
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break;
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}
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if (sol_compat) {
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if (regs & D7S_FLIP)
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ireg |= D7S_FLIP;
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else
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ireg &= ~D7S_FLIP;
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}
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writeb(ireg, p->regs);
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break;
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case D7SIOCRD:
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/* retrieve device register values
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* NOTE: Solaris implementation returns D7S_FLIP bit
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* as toggled by user, even though it does not honor it.
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* This driver will not misinform you about the state
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* of your hardware while in sol_compat mode
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*/
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if (put_user(regs, (int __user *) arg)) {
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error = -EFAULT;
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break;
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}
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break;
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case D7SIOCTM:
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/* toggle device mode-- flip display orientation */
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regs ^= D7S_FLIP;
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writeb(regs, p->regs);
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break;
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}
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mutex_unlock(&d7s_mutex);
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return error;
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}
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static const struct file_operations d7s_fops = {
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.owner = THIS_MODULE,
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.unlocked_ioctl = d7s_ioctl,
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.compat_ioctl = compat_ptr_ioctl,
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.open = d7s_open,
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.release = d7s_release,
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.llseek = noop_llseek,
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};
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static struct miscdevice d7s_miscdev = {
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.minor = D7S_MINOR,
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.name = DRIVER_NAME,
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.fops = &d7s_fops
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};
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static int d7s_probe(struct platform_device *op)
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{
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struct device_node *opts;
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int err = -EINVAL;
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struct d7s *p;
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u8 regs;
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if (d7s_device)
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goto out;
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p = devm_kzalloc(&op->dev, sizeof(*p), GFP_KERNEL);
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err = -ENOMEM;
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if (!p)
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goto out;
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p->regs = of_ioremap(&op->resource[0], 0, sizeof(u8), "d7s");
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if (!p->regs) {
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printk(KERN_ERR PFX "Cannot map chip registers\n");
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goto out;
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}
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err = misc_register(&d7s_miscdev);
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if (err) {
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printk(KERN_ERR PFX "Unable to acquire miscdevice minor %i\n",
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D7S_MINOR);
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goto out_iounmap;
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}
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/* OBP option "d7s-flipped?" is honored as default for the
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* device, and reset default when detached
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*/
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regs = readb(p->regs);
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opts = of_find_node_by_path("/options");
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if (opts &&
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of_get_property(opts, "d7s-flipped?", NULL))
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p->flipped = true;
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if (p->flipped)
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regs |= D7S_FLIP;
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else
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regs &= ~D7S_FLIP;
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writeb(regs, p->regs);
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printk(KERN_INFO PFX "7-Segment Display%pOF at [%s:0x%llx] %s\n",
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op->dev.of_node,
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(regs & D7S_FLIP) ? " (FLIPPED)" : "",
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op->resource[0].start,
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sol_compat ? "in sol_compat mode" : "");
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dev_set_drvdata(&op->dev, p);
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d7s_device = p;
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err = 0;
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of_node_put(opts);
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out:
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return err;
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out_iounmap:
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of_iounmap(&op->resource[0], p->regs, sizeof(u8));
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goto out;
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}
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static int d7s_remove(struct platform_device *op)
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{
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struct d7s *p = dev_get_drvdata(&op->dev);
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u8 regs = readb(p->regs);
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/* Honor OBP d7s-flipped? unless operating in solaris-compat mode */
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if (sol_compat) {
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if (p->flipped)
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regs |= D7S_FLIP;
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else
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regs &= ~D7S_FLIP;
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writeb(regs, p->regs);
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}
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misc_deregister(&d7s_miscdev);
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of_iounmap(&op->resource[0], p->regs, sizeof(u8));
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return 0;
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}
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static const struct of_device_id d7s_match[] = {
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{
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.name = "display7seg",
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},
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{},
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};
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MODULE_DEVICE_TABLE(of, d7s_match);
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static struct platform_driver d7s_driver = {
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.driver = {
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.name = DRIVER_NAME,
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.of_match_table = d7s_match,
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},
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.probe = d7s_probe,
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.remove = d7s_remove,
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};
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module_platform_driver(d7s_driver);
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