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4fc390a198
"devc" can't be NULL here so there is no need to check. Also I removed the "devc = NULL" assignment because devc is stored on stack so it's a no-op. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
478 lines
10 KiB
C
478 lines
10 KiB
C
/*
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* sound/oss/uart401.c
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*
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* MPU-401 UART driver (formerly uart401_midi.c)
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*
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*
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* Copyright (C) by Hannu Savolainen 1993-1997
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*
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* OSS/Free for Linux is distributed under the GNU GENERAL PUBLIC LICENSE (GPL)
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* Version 2 (June 1991). See the "COPYING" file distributed with this software
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* for more info.
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*
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* Changes:
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* Alan Cox Reformatted, removed sound_mem usage, use normal Linux
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* interrupt allocation. Protect against bogus unload
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* Fixed to allow IRQ > 15
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* Christoph Hellwig Adapted to module_init/module_exit
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* Arnaldo C. de Melo got rid of check_region
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*
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* Status:
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* Untested
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*/
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/spinlock.h>
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#include "sound_config.h"
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#include "mpu401.h"
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struct uart401_devc
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{
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int base;
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int irq;
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int *osp;
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void (*midi_input_intr) (int dev, unsigned char data);
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int opened, disabled;
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volatile unsigned char input_byte;
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int my_dev;
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int share_irq;
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spinlock_t lock;
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};
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#define DATAPORT (devc->base)
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#define COMDPORT (devc->base+1)
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#define STATPORT (devc->base+1)
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static int uart401_status(struct uart401_devc *devc)
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{
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return inb(STATPORT);
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}
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#define input_avail(devc) (!(uart401_status(devc)&INPUT_AVAIL))
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#define output_ready(devc) (!(uart401_status(devc)&OUTPUT_READY))
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static void uart401_cmd(struct uart401_devc *devc, unsigned char cmd)
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{
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outb((cmd), COMDPORT);
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}
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static int uart401_read(struct uart401_devc *devc)
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{
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return inb(DATAPORT);
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}
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static void uart401_write(struct uart401_devc *devc, unsigned char byte)
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{
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outb((byte), DATAPORT);
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}
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#define OUTPUT_READY 0x40
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#define INPUT_AVAIL 0x80
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#define MPU_ACK 0xFE
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#define MPU_RESET 0xFF
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#define UART_MODE_ON 0x3F
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static int reset_uart401(struct uart401_devc *devc);
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static void enter_uart_mode(struct uart401_devc *devc);
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static void uart401_input_loop(struct uart401_devc *devc)
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{
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int work_limit=30000;
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while (input_avail(devc) && --work_limit)
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{
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unsigned char c = uart401_read(devc);
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if (c == MPU_ACK)
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devc->input_byte = c;
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else if (devc->opened & OPEN_READ && devc->midi_input_intr)
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devc->midi_input_intr(devc->my_dev, c);
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}
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if(work_limit==0)
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printk(KERN_WARNING "Too much work in interrupt on uart401 (0x%X). UART jabbering ??\n", devc->base);
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}
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irqreturn_t uart401intr(int irq, void *dev_id)
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{
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struct uart401_devc *devc = dev_id;
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if (devc == NULL)
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{
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printk(KERN_ERR "uart401: bad devc\n");
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return IRQ_NONE;
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}
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if (input_avail(devc))
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uart401_input_loop(devc);
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return IRQ_HANDLED;
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}
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static int
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uart401_open(int dev, int mode,
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void (*input) (int dev, unsigned char data),
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void (*output) (int dev)
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)
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{
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struct uart401_devc *devc = (struct uart401_devc *)
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midi_devs[dev]->devc;
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if (devc->opened)
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return -EBUSY;
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/* Flush the UART */
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while (input_avail(devc))
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uart401_read(devc);
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devc->midi_input_intr = input;
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devc->opened = mode;
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enter_uart_mode(devc);
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devc->disabled = 0;
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return 0;
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}
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static void uart401_close(int dev)
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{
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struct uart401_devc *devc = (struct uart401_devc *)
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midi_devs[dev]->devc;
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reset_uart401(devc);
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devc->opened = 0;
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}
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static int uart401_out(int dev, unsigned char midi_byte)
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{
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int timeout;
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unsigned long flags;
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struct uart401_devc *devc = (struct uart401_devc *)
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midi_devs[dev]->devc;
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if (devc->disabled)
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return 1;
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/*
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* Test for input since pending input seems to block the output.
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*/
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spin_lock_irqsave(&devc->lock,flags);
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if (input_avail(devc))
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uart401_input_loop(devc);
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spin_unlock_irqrestore(&devc->lock,flags);
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/*
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* Sometimes it takes about 13000 loops before the output becomes ready
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* (After reset). Normally it takes just about 10 loops.
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*/
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for (timeout = 30000; timeout > 0 && !output_ready(devc); timeout--);
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if (!output_ready(devc))
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{
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printk(KERN_WARNING "uart401: Timeout - Device not responding\n");
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devc->disabled = 1;
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reset_uart401(devc);
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enter_uart_mode(devc);
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return 1;
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}
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uart401_write(devc, midi_byte);
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return 1;
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}
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static inline int uart401_start_read(int dev)
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{
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return 0;
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}
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static inline int uart401_end_read(int dev)
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{
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return 0;
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}
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static inline void uart401_kick(int dev)
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{
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}
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static inline int uart401_buffer_status(int dev)
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{
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return 0;
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}
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#define MIDI_SYNTH_NAME "MPU-401 UART"
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#define MIDI_SYNTH_CAPS SYNTH_CAP_INPUT
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#include "midi_synth.h"
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static const struct midi_operations uart401_operations =
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{
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.owner = THIS_MODULE,
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.info = {"MPU-401 (UART) MIDI", 0, 0, SNDCARD_MPU401},
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.converter = &std_midi_synth,
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.in_info = {0},
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.open = uart401_open,
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.close = uart401_close,
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.outputc = uart401_out,
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.start_read = uart401_start_read,
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.end_read = uart401_end_read,
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.kick = uart401_kick,
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.buffer_status = uart401_buffer_status,
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};
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static void enter_uart_mode(struct uart401_devc *devc)
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{
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int ok, timeout;
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unsigned long flags;
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spin_lock_irqsave(&devc->lock,flags);
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for (timeout = 30000; timeout > 0 && !output_ready(devc); timeout--);
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devc->input_byte = 0;
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uart401_cmd(devc, UART_MODE_ON);
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ok = 0;
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for (timeout = 50000; timeout > 0 && !ok; timeout--)
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if (devc->input_byte == MPU_ACK)
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ok = 1;
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else if (input_avail(devc))
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if (uart401_read(devc) == MPU_ACK)
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ok = 1;
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spin_unlock_irqrestore(&devc->lock,flags);
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}
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static int reset_uart401(struct uart401_devc *devc)
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{
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int ok, timeout, n;
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/*
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* Send the RESET command. Try again if no success at the first time.
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*/
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ok = 0;
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for (n = 0; n < 2 && !ok; n++)
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{
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for (timeout = 30000; timeout > 0 && !output_ready(devc); timeout--);
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devc->input_byte = 0;
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uart401_cmd(devc, MPU_RESET);
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/*
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* Wait at least 25 msec. This method is not accurate so let's make the
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* loop bit longer. Cannot sleep since this is called during boot.
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*/
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for (timeout = 50000; timeout > 0 && !ok; timeout--)
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{
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if (devc->input_byte == MPU_ACK) /* Interrupt */
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ok = 1;
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else if (input_avail(devc))
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{
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if (uart401_read(devc) == MPU_ACK)
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ok = 1;
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}
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}
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}
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/* Flush input before enabling interrupts */
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if (ok)
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uart401_input_loop(devc);
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else
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DDB(printk("Reset UART401 failed - No hardware detected.\n"));
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return ok;
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}
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int probe_uart401(struct address_info *hw_config, struct module *owner)
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{
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struct uart401_devc *devc;
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char *name = "MPU-401 (UART) MIDI";
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int ok = 0;
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unsigned long flags;
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DDB(printk("Entered probe_uart401()\n"));
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/* Default to "not found" */
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hw_config->slots[4] = -1;
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if (!request_region(hw_config->io_base, 4, "MPU-401 UART")) {
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printk(KERN_INFO "uart401: could not request_region(%d, 4)\n", hw_config->io_base);
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return 0;
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}
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devc = kmalloc(sizeof(struct uart401_devc), GFP_KERNEL);
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if (!devc) {
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printk(KERN_WARNING "uart401: Can't allocate memory\n");
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goto cleanup_region;
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}
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devc->base = hw_config->io_base;
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devc->irq = hw_config->irq;
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devc->osp = hw_config->osp;
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devc->midi_input_intr = NULL;
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devc->opened = 0;
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devc->input_byte = 0;
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devc->my_dev = 0;
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devc->share_irq = 0;
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spin_lock_init(&devc->lock);
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spin_lock_irqsave(&devc->lock,flags);
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ok = reset_uart401(devc);
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spin_unlock_irqrestore(&devc->lock,flags);
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if (!ok)
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goto cleanup_devc;
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if (hw_config->name)
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name = hw_config->name;
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if (devc->irq < 0) {
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devc->share_irq = 1;
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devc->irq *= -1;
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} else
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devc->share_irq = 0;
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if (!devc->share_irq)
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if (request_irq(devc->irq, uart401intr, 0, "MPU-401 UART", devc) < 0) {
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printk(KERN_WARNING "uart401: Failed to allocate IRQ%d\n", devc->irq);
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devc->share_irq = 1;
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}
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devc->my_dev = sound_alloc_mididev();
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enter_uart_mode(devc);
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if (devc->my_dev == -1) {
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printk(KERN_INFO "uart401: Too many midi devices detected\n");
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goto cleanup_irq;
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}
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conf_printf(name, hw_config);
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midi_devs[devc->my_dev] = kmemdup(&uart401_operations,
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sizeof(struct midi_operations),
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GFP_KERNEL);
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if (!midi_devs[devc->my_dev]) {
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printk(KERN_ERR "uart401: Failed to allocate memory\n");
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goto cleanup_unload_mididev;
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}
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if (owner)
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midi_devs[devc->my_dev]->owner = owner;
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midi_devs[devc->my_dev]->devc = devc;
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midi_devs[devc->my_dev]->converter = kmemdup(&std_midi_synth,
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sizeof(struct synth_operations),
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GFP_KERNEL);
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if (!midi_devs[devc->my_dev]->converter) {
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printk(KERN_WARNING "uart401: Failed to allocate memory\n");
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goto cleanup_midi_devs;
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}
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strcpy(midi_devs[devc->my_dev]->info.name, name);
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midi_devs[devc->my_dev]->converter->id = "UART401";
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midi_devs[devc->my_dev]->converter->midi_dev = devc->my_dev;
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if (owner)
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midi_devs[devc->my_dev]->converter->owner = owner;
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hw_config->slots[4] = devc->my_dev;
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sequencer_init();
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devc->opened = 0;
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return 1;
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cleanup_midi_devs:
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kfree(midi_devs[devc->my_dev]);
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cleanup_unload_mididev:
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sound_unload_mididev(devc->my_dev);
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cleanup_irq:
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if (!devc->share_irq)
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free_irq(devc->irq, devc);
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cleanup_devc:
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kfree(devc);
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cleanup_region:
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release_region(hw_config->io_base, 4);
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return 0;
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}
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void unload_uart401(struct address_info *hw_config)
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{
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struct uart401_devc *devc;
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int n=hw_config->slots[4];
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/* Not set up */
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if(n==-1 || midi_devs[n]==NULL)
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return;
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/* Not allocated (erm ??) */
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devc = midi_devs[hw_config->slots[4]]->devc;
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if (devc == NULL)
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return;
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reset_uart401(devc);
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release_region(hw_config->io_base, 4);
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if (!devc->share_irq)
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free_irq(devc->irq, devc);
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kfree(midi_devs[devc->my_dev]->converter);
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kfree(midi_devs[devc->my_dev]);
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kfree(devc);
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/* This kills midi_devs[x] */
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sound_unload_mididev(hw_config->slots[4]);
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}
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EXPORT_SYMBOL(probe_uart401);
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EXPORT_SYMBOL(unload_uart401);
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EXPORT_SYMBOL(uart401intr);
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static struct address_info cfg_mpu;
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static int io = -1;
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static int irq = -1;
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module_param(io, int, 0444);
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module_param(irq, int, 0444);
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static int __init init_uart401(void)
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{
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cfg_mpu.irq = irq;
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cfg_mpu.io_base = io;
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/* Can be loaded either for module use or to provide functions
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to others */
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if (cfg_mpu.io_base != -1 && cfg_mpu.irq != -1) {
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printk(KERN_INFO "MPU-401 UART driver Copyright (C) Hannu Savolainen 1993-1997");
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if (!probe_uart401(&cfg_mpu, THIS_MODULE))
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return -ENODEV;
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}
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return 0;
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}
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static void __exit cleanup_uart401(void)
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{
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if (cfg_mpu.io_base != -1 && cfg_mpu.irq != -1)
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unload_uart401(&cfg_mpu);
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}
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module_init(init_uart401);
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module_exit(cleanup_uart401);
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#ifndef MODULE
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static int __init setup_uart401(char *str)
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{
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/* io, irq */
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int ints[3];
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str = get_options(str, ARRAY_SIZE(ints), ints);
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io = ints[1];
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irq = ints[2];
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return 1;
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}
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__setup("uart401=", setup_uart401);
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#endif
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MODULE_LICENSE("GPL");
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