cregit-Linux how code gets into the kernel

Release 4.14 drivers/parport/parport_gsc.c

Directory: drivers/parport
/*
 *      Low-level parallel-support for PC-style hardware integrated in the 
 *      LASI-Controller (on GSC-Bus) for HP-PARISC Workstations
 *
 *      This program is free software; you can redistribute it and/or modify
 *      it under the terms of the GNU General Public License as published by
 *      the Free Software Foundation; either version 2 of the License, or
 *      (at your option) any later version.
 *
 *      (C) 1999-2001 by Helge Deller <deller@gmx.de>
 *
 * 
 * based on parport_pc.c by 
 *          Grant Guenther <grant@torque.net>
 *          Phil Blundell <philb@gnu.org>
 *          Tim Waugh <tim@cyberelk.demon.co.uk>
 *          Jose Renau <renau@acm.org>
 *          David Campbell
 *          Andrea Arcangeli
 */


#undef DEBUG	
/* undef for production */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include <linux/sysctl.h>

#include <asm/io.h>
#include <asm/dma.h>
#include <linux/uaccess.h>
#include <asm/superio.h>

#include <linux/parport.h>
#include <asm/pdc.h>
#include <asm/parisc-device.h>
#include <asm/hardware.h>
#include "parport_gsc.h"


MODULE_AUTHOR("Helge Deller <deller@gmx.de>");
MODULE_DESCRIPTION("HP-PARISC PC-style parallel port driver");
MODULE_SUPPORTED_DEVICE("integrated PC-style parallel port");
MODULE_LICENSE("GPL");


/*
 * Clear TIMEOUT BIT in EPP MODE
 *
 * This is also used in SPP detection.
 */

static int clear_epp_timeout(struct parport *pb) { unsigned char r; if (!(parport_gsc_read_status(pb) & 0x01)) return 1; /* To clear timeout some chips require double read */ parport_gsc_read_status(pb); r = parport_gsc_read_status(pb); parport_writeb (r | 0x01, STATUS (pb)); /* Some reset by writing 1 */ parport_writeb (r & 0xfe, STATUS (pb)); /* Others by writing 0 */ r = parport_gsc_read_status(pb); return !(r & 0x01); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)84100.00%1100.00%
Total84100.00%1100.00%

/* * Access functions. * * Most of these aren't static because they may be used by the * parport_xxx_yyy macros. extern __inline__ versions of several * of these are in parport_gsc.h. */
void parport_gsc_init_state(struct pardevice *dev, struct parport_state *s) { s->u.pc.ctr = 0xc | (dev->irq_func ? 0x10 : 0x0); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)35100.00%1100.00%
Total35100.00%1100.00%


void parport_gsc_save_state(struct parport *p, struct parport_state *s) { s->u.pc.ctr = parport_readb (CONTROL (p)); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)31100.00%1100.00%
Total31100.00%1100.00%


void parport_gsc_restore_state(struct parport *p, struct parport_state *s) { parport_writeb (s->u.pc.ctr, CONTROL (p)); }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)31100.00%1100.00%
Total31100.00%1100.00%

struct parport_operations parport_gsc_ops = { .write_data = parport_gsc_write_data, .read_data = parport_gsc_read_data, .write_control = parport_gsc_write_control, .read_control = parport_gsc_read_control, .frob_control = parport_gsc_frob_control, .read_status = parport_gsc_read_status, .enable_irq = parport_gsc_enable_irq, .disable_irq = parport_gsc_disable_irq, .data_forward = parport_gsc_data_forward, .data_reverse = parport_gsc_data_reverse, .init_state = parport_gsc_init_state, .save_state = parport_gsc_save_state, .restore_state = parport_gsc_restore_state, .epp_write_data = parport_ieee1284_epp_write_data, .epp_read_data = parport_ieee1284_epp_read_data, .epp_write_addr = parport_ieee1284_epp_write_addr, .epp_read_addr = parport_ieee1284_epp_read_addr, .ecp_write_data = parport_ieee1284_ecp_write_data, .ecp_read_data = parport_ieee1284_ecp_read_data, .ecp_write_addr = parport_ieee1284_ecp_write_addr, .compat_write_data = parport_ieee1284_write_compat, .nibble_read_data = parport_ieee1284_read_nibble, .byte_read_data = parport_ieee1284_read_byte, .owner = THIS_MODULE, }; /* --- Mode detection ------------------------------------- */ /* * Checks for port existence, all ports support SPP MODE */
static int parport_SPP_supported(struct parport *pb) { unsigned char r, w; /* * first clear an eventually pending EPP timeout * I (sailer@ife.ee.ethz.ch) have an SMSC chipset * that does not even respond to SPP cycles if an EPP * timeout is pending */ clear_epp_timeout(pb); /* Do a simple read-write test to make sure the port exists. */ w = 0xc; parport_writeb (w, CONTROL (pb)); /* Is there a control register that we can read from? Some * ports don't allow reads, so read_control just returns a * software copy. Some ports _do_ allow reads, so bypass the * software copy here. In addition, some bits aren't * writable. */ r = parport_readb (CONTROL (pb)); if ((r & 0xf) == w) { w = 0xe; parport_writeb (w, CONTROL (pb)); r = parport_readb (CONTROL (pb)); parport_writeb (0xc, CONTROL (pb)); if ((r & 0xf) == w) return PARPORT_MODE_PCSPP; } /* Try the data register. The data lines aren't tri-stated at * this stage, so we expect back what we wrote. */ w = 0xaa; parport_gsc_write_data (pb, w); r = parport_gsc_read_data (pb); if (r == w) { w = 0x55; parport_gsc_write_data (pb, w); r = parport_gsc_read_data (pb); if (r == w) return PARPORT_MODE_PCSPP; } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)165100.00%1100.00%
Total165100.00%1100.00%

/* Detect PS/2 support. * * Bit 5 (0x20) sets the PS/2 data direction; setting this high * allows us to read data from the data lines. In theory we would get back * 0xff but any peripheral attached to the port may drag some or all of the * lines down to zero. So if we get back anything that isn't the contents * of the data register we deem PS/2 support to be present. * * Some SPP ports have "half PS/2" ability - you can't turn off the line * drivers, but an external peripheral with sufficiently beefy drivers of * its own can overpower them and assert its own levels onto the bus, from * where they can then be read back as normal. Ports with this property * and the right type of device attached are likely to fail the SPP test, * (as they will appear to have stuck bits) and so the fact that they might * be misdetected here is rather academic. */
static int parport_PS2_supported(struct parport *pb) { int ok = 0; clear_epp_timeout(pb); /* try to tri-state the buffer */ parport_gsc_data_reverse (pb); parport_gsc_write_data(pb, 0x55); if (parport_gsc_read_data(pb) != 0x55) ok++; parport_gsc_write_data(pb, 0xaa); if (parport_gsc_read_data(pb) != 0xaa) ok++; /* cancel input mode */ parport_gsc_data_forward (pb); if (ok) { pb->modes |= PARPORT_MODE_TRISTATE; } else { struct parport_gsc_private *priv = pb->private_data; priv->ctr_writable &= ~0x20; } return ok; }

Contributors

PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)105100.00%1100.00%
Total105100.00%1100.00%

/* --- Initialisation code -------------------------------- */
struct parport *parport_gsc_probe_port(unsigned long base, unsigned long base_hi, int irq, int dma, struct parisc_device *padev) { struct parport_gsc_private *priv; struct parport_operations *ops; struct parport tmp; struct parport *p = &tmp; priv = kzalloc (sizeof (struct parport_gsc_private), GFP_KERNEL); if (!priv) { printk (KERN_DEBUG "parport (0x%lx): no memory!\n", base); return NULL; } ops = kmemdup(&parport_gsc_ops, sizeof(struct parport_operations), GFP_KERNEL); if (!ops) { printk (KERN_DEBUG "parport (0x%lx): no memory for ops!\n", base); kfree (priv); return NULL; } priv->ctr = 0xc; priv->ctr_writable = 0xff; priv->dma_buf = 0; priv->dma_handle = 0; p->base = base; p->base_hi = base_hi; p->irq = irq; p->dma = dma; p->modes = PARPORT_MODE_PCSPP | PARPORT_MODE_SAFEININT; p->ops = ops; p->private_data = priv; p->physport = p; if (!parport_SPP_supported (p)) { /* No port. */ kfree (priv); kfree(ops); return NULL; } parport_PS2_supported (p); if (!(p = parport_register_port(base, PARPORT_IRQ_NONE, PARPORT_DMA_NONE, ops))) { kfree (priv); kfree (ops); return NULL; } p->dev = &padev->dev; p->base_hi = base_hi; p->modes = tmp.modes; p->size = (p->modes & PARPORT_MODE_EPP)?8:3; p->private_data = priv; printk(KERN_INFO "%s: PC-style at 0x%lx", p->name, p->base); p->irq = irq; if (p->irq == PARPORT_IRQ_AUTO) { p->irq = PARPORT_IRQ_NONE; } if (p->irq != PARPORT_IRQ_NONE) { pr_cont(", irq %d", p->irq); if (p->dma == PARPORT_DMA_AUTO) { p->dma = PARPORT_DMA_NONE; } } if (p->dma == PARPORT_DMA_AUTO) /* To use DMA, giving the irq is mandatory (see above) */ p->dma = PARPORT_DMA_NONE; pr_cont(" ["); #define printmode(x) {if(p->modes&PARPORT_MODE_##x){pr_cont("%s%s",f?",":"",#x);f++;}} { int f = 0; printmode(PCSPP); printmode(TRISTATE); printmode(COMPAT) printmode(EPP); // printmode(ECP); // printmode(DMA); } #undef printmode pr_cont("]\n"); if (p->irq != PARPORT_IRQ_NONE) { if (request_irq (