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00977a59b9
linux/drivers/sbus/char/bpp.c
Arjan van de Ven 00977a59b9 [PATCH] mark struct file_operations const 6 
Many struct file_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-12 09:48:45 -08:00

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/*
* drivers/sbus/char/bpp.c
*
* Copyright (c) 1995 Picture Elements
* Stephen Williams (steve@icarus.com)
* Gus Baldauf (gbaldauf@ix.netcom.com)
*
* Linux/SPARC port by Peter Zaitcev.
* Integration into SPARC tree by Tom Dyas.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/smp_lock.h>
#include <linux/spinlock.h>
#include <linux/timer.h>
#include <linux/ioport.h>
#include <linux/major.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#if defined(__i386__)
# include <asm/system.h>
#endif
#if defined(__sparc__)
# include <linux/init.h>
# include <linux/delay.h> /* udelay() */
# include <asm/oplib.h> /* OpenProm Library */
# include <asm/sbus.h>
#endif
#include <asm/bpp.h>
#define BPP_PROBE_CODE 0x55
#define BPP_DELAY 100
static const unsigned BPP_MAJOR = LP_MAJOR;
static const char* dev_name = "bpp";
/* When switching from compatibility to a mode where I can read, try
the following mode first. */
/* const unsigned char DEFAULT_ECP = 0x10; */
static const unsigned char DEFAULT_ECP = 0x30;
static const unsigned char DEFAULT_NIBBLE = 0x00;
/*
* These are 1284 time constraints, in units of jiffies.
*/
static const unsigned long TIME_PSetup = 1;
static const unsigned long TIME_PResponse = 6;
static const unsigned long TIME_IDLE_LIMIT = 2000;
/*
* One instance per supported subdevice...
*/
# define BPP_NO 3
enum IEEE_Mode { COMPATIBILITY, NIBBLE, ECP, ECP_RLE, EPP };
struct inst {
unsigned present : 1; /* True if the hardware exists */
unsigned enhanced : 1; /* True if the hardware in "enhanced" */
unsigned opened : 1; /* True if the device is opened already */
unsigned run_flag : 1; /* True if waiting for a repeate byte */
unsigned char direction; /* 0 --> out, 0x20 --> IN */
unsigned char pp_state; /* State of host controlled pins. */
enum IEEE_Mode mode;
unsigned char run_length;
unsigned char repeat_byte;
};
static struct inst instances[BPP_NO];
#if defined(__i386__)
static const unsigned short base_addrs[BPP_NO] = { 0x278, 0x378, 0x3bc };
/*
* These are for data access.
* Control lines accesses are hidden in set_bits() and get_bits().
* The exception is the probe procedure, which is system-dependent.
*/
#define bpp_outb_p(data, base) outb_p((data), (base))
#define bpp_inb(base) inb(base)
#define bpp_inb_p(base) inb_p(base)
/*
* This method takes the pin values mask and sets the hardware pins to
* the requested value: 1 == high voltage, 0 == low voltage. This
* burries the annoying PC bit inversion and preserves the direction
* flag.
*/
static void set_pins(unsigned short pins, unsigned minor)
{
unsigned char bits = instances[minor].direction; /* == 0x20 */
if (! (pins & BPP_PP_nStrobe)) bits |= 1;
if (! (pins & BPP_PP_nAutoFd)) bits |= 2;
if ( pins & BPP_PP_nInit) bits |= 4;
if (! (pins & BPP_PP_nSelectIn)) bits |= 8;
instances[minor].pp_state = bits;
outb_p(bits, base_addrs[minor]+2);
}
static unsigned short get_pins(unsigned minor)
{
unsigned short bits = 0;
unsigned value = instances[minor].pp_state;
if (! (value & 0x01)) bits |= BPP_PP_nStrobe;
if (! (value & 0x02)) bits |= BPP_PP_nAutoFd;
if (value & 0x04) bits |= BPP_PP_nInit;
if (! (value & 0x08)) bits |= BPP_PP_nSelectIn;
value = inb_p(base_addrs[minor]+1);
if (value & 0x08) bits |= BPP_GP_nFault;
if (value & 0x10) bits |= BPP_GP_Select;
if (value & 0x20) bits |= BPP_GP_PError;
if (value & 0x40) bits |= BPP_GP_nAck;
if (! (value & 0x80)) bits |= BPP_GP_Busy;
return bits;
}
#endif /* __i386__ */
#if defined(__sparc__)
/*
* Register block
*/
/* DMA registers */
#define BPP_CSR 0x00
#define BPP_ADDR 0x04
#define BPP_BCNT 0x08
#define BPP_TST_CSR 0x0C
/* Parallel Port registers */
#define BPP_HCR 0x10
#define BPP_OCR 0x12
#define BPP_DR 0x14
#define BPP_TCR 0x15
#define BPP_OR 0x16
#define BPP_IR 0x17
#define BPP_ICR 0x18
#define BPP_SIZE 0x1A
/* BPP_CSR. Bits of type RW1 are cleared with writting '1'. */
#define P_DEV_ID_MASK 0xf0000000 /* R */
#define P_DEV_ID_ZEBRA 0x40000000
#define P_DEV_ID_L64854 0xa0000000 /* == NCR 89C100+89C105. Pity. */
#define P_NA_LOADED 0x08000000 /* R NA wirtten but was not used */
#define P_A_LOADED 0x04000000 /* R */
#define P_DMA_ON 0x02000000 /* R DMA is not disabled */
#define P_EN_NEXT 0x01000000 /* RW */
#define P_TCI_DIS 0x00800000 /* RW TCI forbidden from interrupts */
#define P_DIAG 0x00100000 /* RW Disables draining and resetting
of P-FIFO on loading of P_ADDR*/
#define P_BURST_SIZE 0x000c0000 /* RW SBus burst size */
#define P_BURST_8 0x00000000
#define P_BURST_4 0x00040000
#define P_BURST_1 0x00080000 /* "No burst" write */
#define P_TC 0x00004000 /* RW1 Term Count, can be cleared when
P_EN_NEXT=1 */
#define P_EN_CNT 0x00002000 /* RW */
#define P_EN_DMA 0x00000200 /* RW */
#define P_WRITE 0x00000100 /* R DMA dir, 1=to ram, 0=to port */
#define P_RESET 0x00000080 /* RW */
#define P_SLAVE_ERR 0x00000040 /* RW1 Access size error */
#define P_INVALIDATE 0x00000020 /* W Drop P-FIFO */
#define P_INT_EN 0x00000010 /* RW OK to P_INT_PEND||P_ERR_PEND */
#define P_DRAINING 0x0000000c /* R P-FIFO is draining to memory */
#define P_ERR_PEND 0x00000002 /* R */
#define P_INT_PEND 0x00000001 /* R */
/* BPP_HCR. Time is in increments of SBus clock. */
#define P_HCR_TEST 0x8000 /* Allows buried counters to be read */
#define P_HCR_DSW 0x7f00 /* Data strobe width (in ticks) */
#define P_HCR_DDS 0x007f /* Data setup before strobe (in ticks) */
/* BPP_OCR. */
#define P_OCR_MEM_CLR 0x8000
#define P_OCR_DATA_SRC 0x4000 /* ) */
#define P_OCR_DS_DSEL 0x2000 /* ) Bidirectional */
#define P_OCR_BUSY_DSEL 0x1000 /* ) selects */
#define P_OCR_ACK_DSEL 0x0800 /* ) */
#define P_OCR_EN_DIAG 0x0400
#define P_OCR_BUSY_OP 0x0200 /* Busy operation */
#define P_OCR_ACK_OP 0x0100 /* Ack operation */
#define P_OCR_SRST 0x0080 /* Reset state machines. Not selfcleaning. */
#define P_OCR_IDLE 0x0008 /* PP data transfer state machine is idle */
#define P_OCR_V_ILCK 0x0002 /* Versatec faded. Zebra only. */
#define P_OCR_EN_VER 0x0001 /* Enable Versatec (0 - enable). Zebra only. */
/* BPP_TCR */
#define P_TCR_DIR 0x08
#define P_TCR_BUSY 0x04
#define P_TCR_ACK 0x02
#define P_TCR_DS 0x01 /* Strobe */
/* BPP_OR */
#define P_OR_V3 0x20 /* ) */
#define P_OR_V2 0x10 /* ) on Zebra only */
#define P_OR_V1 0x08 /* ) */
#define P_OR_INIT 0x04
#define P_OR_AFXN 0x02 /* Auto Feed */
#define P_OR_SLCT_IN 0x01
/* BPP_IR */
#define P_IR_PE 0x04
#define P_IR_SLCT 0x02
#define P_IR_ERR 0x01
/* BPP_ICR */
#define P_DS_IRQ 0x8000 /* RW1 */
#define P_ACK_IRQ 0x4000 /* RW1 */
#define P_BUSY_IRQ 0x2000 /* RW1 */
#define P_PE_IRQ 0x1000 /* RW1 */
#define P_SLCT_IRQ 0x0800 /* RW1 */
#define P_ERR_IRQ 0x0400 /* RW1 */
#define P_DS_IRQ_EN 0x0200 /* RW Always on rising edge */
#define P_ACK_IRQ_EN 0x0100 /* RW Always on rising edge */
#define P_BUSY_IRP 0x0080 /* RW 1= rising edge */
#define P_BUSY_IRQ_EN 0x0040 /* RW */
#define P_PE_IRP 0x0020 /* RW 1= rising edge */
#define P_PE_IRQ_EN 0x0010 /* RW */
#define P_SLCT_IRP 0x0008 /* RW 1= rising edge */
#define P_SLCT_IRQ_EN 0x0004 /* RW */
#define P_ERR_IRP 0x0002 /* RW1 1= rising edge */
#define P_ERR_IRQ_EN 0x0001 /* RW */
static void __iomem *base_addrs[BPP_NO];
#define bpp_outb_p(data, base) sbus_writeb(data, (base) + BPP_DR)
#define bpp_inb_p(base) sbus_readb((base) + BPP_DR)
#define bpp_inb(base) sbus_readb((base) + BPP_DR)
static void set_pins(unsigned short pins, unsigned minor)
{
void __iomem *base = base_addrs[minor];
unsigned char bits_tcr = 0, bits_or = 0;
if (instances[minor].direction & 0x20) bits_tcr |= P_TCR_DIR;
if ( pins & BPP_PP_nStrobe) bits_tcr |= P_TCR_DS;
if ( pins & BPP_PP_nAutoFd) bits_or |= P_OR_AFXN;
if (! (pins & BPP_PP_nInit)) bits_or |= P_OR_INIT;
if (! (pins & BPP_PP_nSelectIn)) bits_or |= P_OR_SLCT_IN;
sbus_writeb(bits_or, base + BPP_OR);
sbus_writeb(bits_tcr, base + BPP_TCR);
}
/*
* i386 people read output pins from a software image.
* We may get them back from hardware.
* Again, inversion of pins must he buried here.
*/
static unsigned short get_pins(unsigned minor)
{
void __iomem *base = base_addrs[minor];
unsigned short bits = 0;
unsigned value_tcr = sbus_readb(base + BPP_TCR);
unsigned value_ir = sbus_readb(base + BPP_IR);
unsigned value_or = sbus_readb(base + BPP_OR);
if (value_tcr & P_TCR_DS) bits |= BPP_PP_nStrobe;
if (value_or & P_OR_AFXN) bits |= BPP_PP_nAutoFd;
if (! (value_or & P_OR_INIT)) bits |= BPP_PP_nInit;
if (! (value_or & P_OR_SLCT_IN)) bits |= BPP_PP_nSelectIn;
if (value_ir & P_IR_ERR) bits |= BPP_GP_nFault;
if (! (value_ir & P_IR_SLCT)) bits |= BPP_GP_Select;
if (! (value_ir & P_IR_PE)) bits |= BPP_GP_PError;
if (! (value_tcr & P_TCR_ACK)) bits |= BPP_GP_nAck;
if (value_tcr & P_TCR_BUSY) bits |= BPP_GP_Busy;
return bits;
}
#endif /* __sparc__ */
static void snooze(unsigned long snooze_time, unsigned minor)
{
schedule_timeout_uninterruptible(snooze_time + 1);
}
static int wait_for(unsigned short set, unsigned short clr,
unsigned long delay, unsigned minor)
{
unsigned short pins = get_pins(minor);
unsigned long extime = 0;
/*
* Try a real fast scan for the first jiffy, in case the device
* responds real good. The first while loop guesses an expire
* time accounting for possible wraparound of jiffies.
*/
while (time_after_eq(jiffies, extime)) extime = jiffies + 1;
while ( (time_before(jiffies, extime))
&& (((pins & set) != set) || ((pins & clr) != 0)) ) {
pins = get_pins(minor);
}
delay -= 1;
/*
* If my delay expired or the pins are still not where I want
* them, then resort to using the timer and greatly reduce my
* sample rate. If the peripheral is going to be slow, this will
* give the CPU up to some more worthy process.
*/
while ( delay && (((pins & set) != set) || ((pins & clr) != 0)) ) {
snooze(1, minor);
pins = get_pins(minor);
delay -= 1;
}
if (delay == 0) return -1;
else return pins;
}
/*
* Return ZERO(0) If the negotiation succeeds, an errno otherwise. An
* errno means something broke, and I do not yet know how to fix it.
*/
static int negotiate(unsigned char mode, unsigned minor)
{
int rc;
unsigned short pins = get_pins(minor);
if (pins & BPP_PP_nSelectIn) return -EIO;
/* Event 0: Write the mode to the data lines */
bpp_outb_p(mode, base_addrs[minor]);
snooze(TIME_PSetup, minor);
/* Event 1: Strobe the mode code into the peripheral */
set_pins(BPP_PP_nSelectIn|BPP_PP_nStrobe|BPP_PP_nInit, minor);
/* Wait for Event 2: Peripheral responds as a 1284 device. */
rc = wait_for(BPP_GP_PError|BPP_GP_Select|BPP_GP_nFault,
BPP_GP_nAck,
TIME_PResponse,
minor);
if (rc == -1) return -ETIMEDOUT;
/* Event 3: latch extensibility request */
set_pins(BPP_PP_nSelectIn|BPP_PP_nInit, minor);
/* ... quick nap while peripheral ponders the byte i'm sending...*/
snooze(1, minor);
/* Event 4: restore strobe, to ACK peripheral's response. */
set_pins(BPP_PP_nSelectIn|BPP_PP_nAutoFd|BPP_PP_nStrobe|BPP_PP_nInit, minor);
/* Wait for Event 6: Peripheral latches response bits */
rc = wait_for(BPP_GP_nAck, 0, TIME_PSetup+TIME_PResponse, minor);
if (rc == -1) return -EIO;
/* A 1284 device cannot refuse nibble mode */
if (mode == DEFAULT_NIBBLE) return 0;
if (pins & BPP_GP_Select) return 0;
return -EPROTONOSUPPORT;
}
static int terminate(unsigned minor)
{
int rc;
/* Event 22: Request termination of 1284 mode */
set_pins(BPP_PP_nAutoFd|BPP_PP_nStrobe|BPP_PP_nInit, minor);
/* Wait for Events 23 and 24: ACK termination request. */
rc = wait_for(BPP_GP_Busy|BPP_GP_nFault,
BPP_GP_nAck,
TIME_PSetup+TIME_PResponse,
minor);
instances[minor].direction = 0;
instances[minor].mode = COMPATIBILITY;
if (rc == -1) {
return -EIO;
}
/* Event 25: Handshake by lowering nAutoFd */
set_pins(BPP_PP_nStrobe|BPP_PP_nInit, minor);
/* Event 26: Peripheral wiggles lines... */
/* Event 27: Peripheral sets nAck HIGH to ack handshake */
rc = wait_for(BPP_GP_nAck, 0, TIME_PResponse, minor);
if (rc == -1) {
set_pins(BPP_PP_nAutoFd|BPP_PP_nStrobe|BPP_PP_nInit, minor);
return -EIO;
}
/* Event 28: Finish phase by raising nAutoFd */
set_pins(BPP_PP_nAutoFd|BPP_PP_nStrobe|BPP_PP_nInit, minor);
return 0;
}
static DEFINE_SPINLOCK(bpp_open_lock);
/*
* Allow only one process to open the device at a time.
*/
static int bpp_open(struct inode *inode, struct file *f)
{
unsigned minor = iminor(inode);
int ret;
spin_lock(&bpp_open_lock);
ret = 0;
if (minor >= BPP_NO) {
ret = -ENODEV;
} else {
if (! instances[minor].present) {
ret = -ENODEV;
} else {
if (instances[minor].opened)
ret = -EBUSY;
else
instances[minor].opened = 1;
}
}
spin_unlock(&bpp_open_lock);
return ret;
}
/*
* When the process closes the device, this method is called to clean
* up and reset the hardware. Always leave the device in compatibility
* mode as this is a reasonable place to clean up from messes made by
* ioctls, or other mayhem.
*/
static int bpp_release(struct inode *inode, struct file *f)
{
unsigned minor = iminor(inode);
spin_lock(&bpp_open_lock);
instances[minor].opened = 0;
if (instances[minor].mode != COMPATIBILITY)
terminate(minor);
spin_unlock(&bpp_open_lock);
return 0;
}
static long read_nibble(unsigned minor, char __user *c, unsigned long cnt)
{
unsigned long remaining = cnt;
long rc;
while (remaining > 0) {
unsigned char byte = 0;
int pins;
/* Event 7: request nibble */
set_pins(BPP_PP_nSelectIn|BPP_PP_nStrobe, minor);
/* Wait for event 9: Peripher strobes first nibble */
pins = wait_for(0, BPP_GP_nAck, TIME_IDLE_LIMIT, minor);
if (pins == -1) return -ETIMEDOUT;
/* Event 10: I handshake nibble */
set_pins(BPP_PP_nSelectIn|BPP_PP_nStrobe|BPP_PP_nAutoFd, minor);
if (pins & BPP_GP_nFault) byte |= 0x01;
if (pins & BPP_GP_Select) byte |= 0x02;
if (pins & BPP_GP_PError) byte |= 0x04;
if (pins & BPP_GP_Busy) byte |= 0x08;
/* Wait for event 11: Peripheral handshakes nibble */
rc = wait_for(BPP_GP_nAck, 0, TIME_PResponse, minor);
/* Event 7: request nibble */
set_pins(BPP_PP_nSelectIn|BPP_PP_nStrobe, minor);
/* Wait for event 9: Peripher strobes first nibble */
pins = wait_for(0, BPP_GP_nAck, TIME_PResponse, minor);
if (rc == -1) return -ETIMEDOUT;
/* Event 10: I handshake nibble */
set_pins(BPP_PP_nSelectIn|BPP_PP_nStrobe|BPP_PP_nAutoFd, minor);
if (pins & BPP_GP_nFault) byte |= 0x10;
if (pins & BPP_GP_Select) byte |= 0x20;
if (pins & BPP_GP_PError) byte |= 0x40;
if (pins & BPP_GP_Busy) byte |= 0x80;
if (put_user(byte, c))
return -EFAULT;
c += 1;
remaining -= 1;
/* Wait for event 11: Peripheral handshakes nibble */
rc = wait_for(BPP_GP_nAck, 0, TIME_PResponse, minor);
if (rc == -1) return -EIO;
}
return cnt - remaining;
}
static long read_ecp(unsigned minor, char __user *c, unsigned long cnt)
{
unsigned long remaining;
long rc;
/* Turn ECP mode from forward to reverse if needed. */
if (! instances[minor].direction) {
unsigned short pins = get_pins(minor);
/* Event 38: Turn the bus around */
instances[minor].direction = 0x20;
pins &= ~BPP_PP_nAutoFd;
set_pins(pins, minor);
/* Event 39: Set pins for reverse mode. */
snooze(TIME_PSetup, minor);
set_pins(BPP_PP_nStrobe|BPP_PP_nSelectIn, minor);
/* Wait for event 40: Peripheral ready to be strobed */
rc = wait_for(0, BPP_GP_PError, TIME_PResponse, minor);
if (rc == -1) return -ETIMEDOUT;
}
remaining = cnt;
while (remaining > 0) {
/* If there is a run length for a repeated byte, repeat */
/* that byte a few times. */
if (instances[minor].run_length && !instances[minor].run_flag) {
char buffer[128];
unsigned idx;
unsigned repeat = remaining < instances[minor].run_length
? remaining
: instances[minor].run_length;
for (idx = 0 ; idx < repeat ; idx += 1)
buffer[idx] = instances[minor].repeat_byte;
if (copy_to_user(c, buffer, repeat))
return -EFAULT;
remaining -= repeat;
c += repeat;
instances[minor].run_length -= repeat;
}
if (remaining == 0) break;
/* Wait for Event 43: Data active on the bus. */
rc = wait_for(0, BPP_GP_nAck, TIME_IDLE_LIMIT, minor);
if (rc == -1) break;
if (rc & BPP_GP_Busy) {
/* OK, this is data. read it in. */
unsigned char byte = bpp_inb(base_addrs[minor]);
if (put_user(byte, c))
return -EFAULT;
c += 1;
remaining -= 1;
if (instances[minor].run_flag) {
instances[minor].repeat_byte = byte;
instances[minor].run_flag = 0;
}
} else {
unsigned char byte = bpp_inb(base_addrs[minor]);
if (byte & 0x80) {
printk("bpp%d: "
"Ignoring ECP channel %u from device.\n",
minor, byte & 0x7f);
} else {
instances[minor].run_length = byte;
instances[minor].run_flag = 1;
}
}
/* Event 44: I got it. */
set_pins(BPP_PP_nStrobe|BPP_PP_nAutoFd|BPP_PP_nSelectIn, minor);
/* Wait for event 45: peripheral handshake */
rc = wait_for(BPP_GP_nAck, 0, TIME_PResponse, minor);
if (rc == -1) return -ETIMEDOUT;
/* Event 46: Finish handshake */
set_pins(BPP_PP_nStrobe|BPP_PP_nSelectIn, minor);
}
return cnt - remaining;
}
static ssize_t bpp_read(struct file *f, char __user *c, size_t cnt, loff_t * ppos)
{
long rc;
unsigned minor = iminor(f->f_path.dentry->d_inode);
if (minor >= BPP_NO) return -ENODEV;
if (!instances[minor].present) return -ENODEV;
switch (instances[minor].mode) {
default:
if (instances[minor].mode != COMPATIBILITY)
terminate(minor);
if (instances[minor].enhanced) {
/* For now, do all reads with ECP-RLE mode */
unsigned short pins;
rc = negotiate(DEFAULT_ECP, minor);
if (rc < 0) break;
instances[minor].mode = ECP_RLE;
/* Event 30: set nAutoFd low to setup for ECP mode */
pins = get_pins(minor);
pins &= ~BPP_PP_nAutoFd;
set_pins(pins, minor);
/* Wait for Event 31: peripheral ready */
rc = wait_for(BPP_GP_PError, 0, TIME_PResponse, minor);
if (rc == -1) return -ETIMEDOUT;
rc = read_ecp(minor, c, cnt);
} else {
rc = negotiate(DEFAULT_NIBBLE, minor);
if (rc < 0) break;
instances[minor].mode = NIBBLE;
rc = read_nibble(minor, c, cnt);
}
break;
case NIBBLE:
rc = read_nibble(minor, c, cnt);
break;
case ECP:
case ECP_RLE:
rc = read_ecp(minor, c, cnt);
break;
}
return rc;
}
/*
* Compatibility mode handshaking is a matter of writing data,
* strobing it, and waiting for the printer to stop being busy.
*/
static long write_compat(unsigned minor, const char __user *c, unsigned long cnt)
{
long rc;
unsigned short pins = get_pins(minor);
unsigned long remaining = cnt;
while (remaining > 0) {
unsigned char byte;
if (get_user(byte, c))
return -EFAULT;
c += 1;
rc = wait_for(BPP_GP_nAck, BPP_GP_Busy, TIME_IDLE_LIMIT, minor);
if (rc == -1) return -ETIMEDOUT;
bpp_outb_p(byte, base_addrs[minor]);
remaining -= 1;
/* snooze(1, minor); */
pins &= ~BPP_PP_nStrobe;
set_pins(pins, minor);
rc = wait_for(BPP_GP_Busy, 0, TIME_PResponse, minor);
pins |= BPP_PP_nStrobe;
set_pins(pins, minor);
}
return cnt - remaining;
}
/*
* Write data using ECP mode. Watch out that the port may be set up
* for reading. If so, turn the port around.
*/
static long write_ecp(unsigned minor, const char __user *c, unsigned long cnt)
{
unsigned short pins = get_pins(minor);
unsigned long remaining = cnt;
if (instances[minor].direction) {
int rc;
/* Event 47 Request bus be turned around */
pins |= BPP_PP_nInit;
set_pins(pins, minor);
/* Wait for Event 49: Peripheral relinquished bus */
rc = wait_for(BPP_GP_PError, 0, TIME_PResponse, minor);
pins |= BPP_PP_nAutoFd;
instances[minor].direction = 0;
set_pins(pins, minor);
}
while (remaining > 0) {
unsigned char byte;
int rc;
if (get_user(byte, c))
return -EFAULT;
rc = wait_for(0, BPP_GP_Busy, TIME_PResponse, minor);
if (rc == -1) return -ETIMEDOUT;
c += 1;
bpp_outb_p(byte, base_addrs[minor]);
pins &= ~BPP_PP_nStrobe;
set_pins(pins, minor);
pins |= BPP_PP_nStrobe;
rc = wait_for(BPP_GP_Busy, 0, TIME_PResponse, minor);
if (rc == -1) return -EIO;
set_pins(pins, minor);
}
return cnt - remaining;
}
/*
* Write to the peripheral. Be sensitive of the current mode. If I'm
* in a mode that can be turned around (ECP) then just do
* that. Otherwise, terminate and do my writing in compat mode. This
* is the safest course as any device can handle it.
*/
static ssize_t bpp_write(struct file *f, const char __user *c, size_t cnt, loff_t * ppos)
{
long errno = 0;
unsigned minor = iminor(f->f_path.dentry->d_inode);
if (minor >= BPP_NO) return -ENODEV;
if (!instances[minor].present) return -ENODEV;
switch (instances[minor].mode) {
case ECP:
case ECP_RLE:
errno = write_ecp(minor, c, cnt);
break;
case COMPATIBILITY:
errno = write_compat(minor, c, cnt);
break;
default:
terminate(minor);
errno = write_compat(minor, c, cnt);
}
return errno;
}
static int bpp_ioctl(struct inode *inode, struct file *f, unsigned int cmd,
unsigned long arg)
{
int errno = 0;
unsigned minor = iminor(inode);
if (minor >= BPP_NO) return -ENODEV;
if (!instances[minor].present) return -ENODEV;
switch (cmd) {
case BPP_PUT_PINS:
set_pins(arg, minor);
break;
case BPP_GET_PINS:
errno = get_pins(minor);
break;
case BPP_PUT_DATA:
bpp_outb_p(arg, base_addrs[minor]);
break;
case BPP_GET_DATA:
errno = bpp_inb_p(base_addrs[minor]);
break;
case BPP_SET_INPUT:
if (arg)
if (instances[minor].enhanced) {
unsigned short bits = get_pins(minor);
instances[minor].direction = 0x20;
set_pins(bits, minor);
} else {
errno = -ENOTTY;
}
else {
unsigned short bits = get_pins(minor);
instances[minor].direction = 0x00;
set_pins(bits, minor);
}
break;
default:
errno = -EINVAL;
}
return errno;
}
static const struct file_operations bpp_fops = {
.owner = THIS_MODULE,
.read = bpp_read,
.write = bpp_write,
.ioctl = bpp_ioctl,
.open = bpp_open,
.release = bpp_release,
};
#if defined(__i386__)
#define collectLptPorts() {}
static void probeLptPort(unsigned idx)
{
unsigned int testvalue;
const unsigned short lpAddr = base_addrs[idx];
instances[idx].present = 0;
instances[idx].enhanced = 0;
instances[idx].direction = 0;
instances[idx].mode = COMPATIBILITY;
instances[idx].run_length = 0;
instances[idx].run_flag = 0;
if (!request_region(lpAddr,3, dev_name)) return;
/*
* First, make sure the instance exists. Do this by writing to
* the data latch and reading the value back. If the port *is*
* present, test to see if it supports extended-mode
* operation. This will be required for IEEE1284 reverse
* transfers.
*/
outb_p(BPP_PROBE_CODE, lpAddr);
for (testvalue=0; testvalue<BPP_DELAY; testvalue++)
;
testvalue = inb_p(lpAddr);
if (testvalue == BPP_PROBE_CODE) {
unsigned save;
instances[idx].present = 1;
save = inb_p(lpAddr+2);
for (testvalue=0; testvalue<BPP_DELAY; testvalue++)
;
outb_p(save|0x20, lpAddr+2);
for (testvalue=0; testvalue<BPP_DELAY; testvalue++)
;
outb_p(~BPP_PROBE_CODE, lpAddr);
for (testvalue=0; testvalue<BPP_DELAY; testvalue++)
;
testvalue = inb_p(lpAddr);
if ((testvalue&0xff) == (0xff&~BPP_PROBE_CODE))
instances[idx].enhanced = 0;
else
instances[idx].enhanced = 1;
outb_p(save, lpAddr+2);
}
else {
release_region(lpAddr,3);
}
/*
* Leave the port in compat idle mode.
*/
set_pins(BPP_PP_nAutoFd|BPP_PP_nStrobe|BPP_PP_nInit, idx);
printk("bpp%d: Port at 0x%03x: Enhanced mode %s\n", idx, base_addrs[idx],
instances[idx].enhanced? "SUPPORTED" : "UNAVAILABLE");
}
static inline void freeLptPort(int idx)
{
release_region(base_addrs[idx], 3);
}
#endif
#if defined(__sparc__)
static void __iomem *map_bpp(struct sbus_dev *dev, int idx)
{
return sbus_ioremap(&dev->resource[0], 0, BPP_SIZE, "bpp");
}
static int collectLptPorts(void)
{
struct sbus_bus *bus;
struct sbus_dev *dev;
int count;
count = 0;
for_all_sbusdev(dev, bus) {
if (strcmp(dev->prom_name, "SUNW,bpp") == 0) {
if (count >= BPP_NO) {
printk(KERN_NOTICE
"bpp: More than %d bpp ports,"
" rest is ignored\n", BPP_NO);
return count;
}
base_addrs[count] = map_bpp(dev, count);
count++;
}
}
return count;
}
static void probeLptPort(unsigned idx)
{
void __iomem *rp = base_addrs[idx];
__u32 csr;
char *brand;
instances[idx].present = 0;
instances[idx].enhanced = 0;
instances[idx].direction = 0;
instances[idx].mode = COMPATIBILITY;
instances[idx].run_length = 0;
instances[idx].run_flag = 0;
if (!rp) return;
instances[idx].present = 1;
instances[idx].enhanced = 1; /* Sure */
csr = sbus_readl(rp + BPP_CSR);
if ((csr & P_DRAINING) != 0 && (csr & P_ERR_PEND) == 0) {
udelay(20);
csr = sbus_readl(rp + BPP_CSR);
if ((csr & P_DRAINING) != 0 && (csr & P_ERR_PEND) == 0) {
printk("bpp%d: DRAINING still active (0x%08x)\n", idx, csr);
}
}
printk("bpp%d: reset with 0x%08x ..", idx, csr);
sbus_writel((csr | P_RESET) & ~P_INT_EN, rp + BPP_CSR);
udelay(500);
sbus_writel(sbus_readl(rp + BPP_CSR) & ~P_RESET, rp + BPP_CSR);
csr = sbus_readl(rp + BPP_CSR);
printk(" done with csr=0x%08x ocr=0x%04x\n",
csr, sbus_readw(rp + BPP_OCR));
switch (csr & P_DEV_ID_MASK) {
case P_DEV_ID_ZEBRA:
brand = "Zebra";
break;
case P_DEV_ID_L64854:
brand = "DMA2";
break;
default:
brand = "Unknown";
}
printk("bpp%d: %s at %p\n", idx, brand, rp);
/*
* Leave the port in compat idle mode.
*/
set_pins(BPP_PP_nAutoFd|BPP_PP_nStrobe|BPP_PP_nInit, idx);
return;
}
static inline void freeLptPort(int idx)
{
sbus_iounmap(base_addrs[idx], BPP_SIZE);
}
#endif
static int __init bpp_init(void)
{
int rc;
unsigned idx;
rc = collectLptPorts();
if (rc == 0)
return -ENODEV;
rc = register_chrdev(BPP_MAJOR, dev_name, &bpp_fops);
if (rc < 0)
return rc;
for (idx = 0; idx < BPP_NO; idx++) {
instances[idx].opened = 0;
probeLptPort(idx);
}
return 0;
}
static void __exit bpp_cleanup(void)
{
unsigned idx;
unregister_chrdev(BPP_MAJOR, dev_name);
for (idx = 0; idx < BPP_NO; idx++) {
if (instances[idx].present)
freeLptPort(idx);
}
}
module_init(bpp_init);
module_exit(bpp_cleanup);
MODULE_LICENSE("GPL");
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