diff options
Diffstat (limited to 'drivers/parport/daisy.c')
| -rw-r--r-- | drivers/parport/daisy.c | 512 |
1 files changed, 512 insertions, 0 deletions
diff --git a/drivers/parport/daisy.c b/drivers/parport/daisy.c new file mode 100644 index 0000000..075c7eb --- /dev/null +++ b/drivers/parport/daisy.c @@ -0,0 +1,512 @@ +/* + * IEEE 1284.3 Parallel port daisy chain and multiplexor code + * + * Copyright (C) 1999, 2000 Tim Waugh <tim@cyberelk.demon.co.uk> + * + * 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. + * + * ??-12-1998: Initial implementation. + * 31-01-1999: Make port-cloning transparent. + * 13-02-1999: Move DeviceID technique from parport_probe. + * 13-03-1999: Get DeviceID from non-IEEE 1284.3 devices too. + * 22-02-2000: Count devices that are actually detected. + * + * Any part of this program may be used in documents licensed under + * the GNU Free Documentation License, Version 1.1 or any later version + * published by the Free Software Foundation. + */ + +#include <linux/module.h> +#include <linux/parport.h> +#include <linux/delay.h> +#include <linux/sched.h> + +#include <asm/current.h> +#include <asm/uaccess.h> + +#undef DEBUG + +#ifdef DEBUG +#define DPRINTK(stuff...) printk (stuff) +#else +#define DPRINTK(stuff...) +#endif + +static struct daisydev { + struct daisydev *next; + struct parport *port; + int daisy; + int devnum; +} *topology = NULL; +static DEFINE_SPINLOCK(topology_lock); + +static int numdevs = 0; + +/* Forward-declaration of lower-level functions. */ +static int mux_present (struct parport *port); +static int num_mux_ports (struct parport *port); +static int select_port (struct parport *port); +static int assign_addrs (struct parport *port); + +/* Add a device to the discovered topology. */ +static void add_dev (int devnum, struct parport *port, int daisy) +{ + struct daisydev *newdev, **p; + newdev = kmalloc (sizeof (struct daisydev), GFP_KERNEL); + if (newdev) { + newdev->port = port; + newdev->daisy = daisy; + newdev->devnum = devnum; + spin_lock(&topology_lock); + for (p = &topology; *p && (*p)->devnum<devnum; p = &(*p)->next) + ; + newdev->next = *p; + *p = newdev; + spin_unlock(&topology_lock); + } +} + +/* Clone a parport (actually, make an alias). */ +static struct parport *clone_parport (struct parport *real, int muxport) +{ + struct parport *extra = parport_register_port (real->base, + real->irq, + real->dma, + real->ops); + if (extra) { + extra->portnum = real->portnum; + extra->physport = real; + extra->muxport = muxport; + real->slaves[muxport-1] = extra; + } + + return extra; +} + +/* Discover the IEEE1284.3 topology on a port -- muxes and daisy chains. + * Return value is number of devices actually detected. */ +int parport_daisy_init (struct parport *port) +{ + int detected = 0; + char *deviceid; + static const char *th[] = { /*0*/"th", "st", "nd", "rd", "th" }; + int num_ports; + int i; + int last_try = 0; + +again: + /* Because this is called before any other devices exist, + * we don't have to claim exclusive access. */ + + /* If mux present on normal port, need to create new + * parports for each extra port. */ + if (port->muxport < 0 && mux_present (port) && + /* don't be fooled: a mux must have 2 or 4 ports. */ + ((num_ports = num_mux_ports (port)) == 2 || num_ports == 4)) { + /* Leave original as port zero. */ + port->muxport = 0; + printk (KERN_INFO + "%s: 1st (default) port of %d-way multiplexor\n", + port->name, num_ports); + for (i = 1; i < num_ports; i++) { + /* Clone the port. */ + struct parport *extra = clone_parport (port, i); + if (!extra) { + if (signal_pending (current)) + break; + + schedule (); + continue; + } + + printk (KERN_INFO + "%s: %d%s port of %d-way multiplexor on %s\n", + extra->name, i + 1, th[i + 1], num_ports, + port->name); + + /* Analyse that port too. We won't recurse + forever because of the 'port->muxport < 0' + test above. */ + parport_daisy_init(extra); + } + } + + if (port->muxport >= 0) + select_port (port); + + parport_daisy_deselect_all (port); + detected += assign_addrs (port); + + /* Count the potential legacy device at the end. */ + add_dev (numdevs++, port, -1); + + /* Find out the legacy device's IEEE 1284 device ID. */ + deviceid = kmalloc (1000, GFP_KERNEL); + if (deviceid) { + if (parport_device_id (numdevs - 1, deviceid, 1000) > 2) + detected++; + + kfree (deviceid); + } + + if (!detected && !last_try) { + /* No devices were detected. Perhaps they are in some + funny state; let's try to reset them and see if + they wake up. */ + parport_daisy_fini (port); + parport_write_control (port, PARPORT_CONTROL_SELECT); + udelay (50); + parport_write_control (port, + PARPORT_CONTROL_SELECT | + PARPORT_CONTROL_INIT); + udelay (50); + last_try = 1; + goto again; + } + + return detected; +} + +/* Forget about devices on a physical port. */ +void parport_daisy_fini (struct parport *port) +{ + struct daisydev **p; + + spin_lock(&topology_lock); + p = &topology; + while (*p) { + struct daisydev *dev = *p; + if (dev->port != port) { + p = &dev->next; + continue; + } + *p = dev->next; + kfree(dev); + } + + /* Gaps in the numbering could be handled better. How should + someone enumerate through all IEEE1284.3 devices in the + topology?. */ + if (!topology) numdevs = 0; + spin_unlock(&topology_lock); + return; +} + +/** + * parport_open - find a device by canonical device number + * @devnum: canonical device number + * @name: name to associate with the device + * @pf: preemption callback + * @kf: kick callback + * @irqf: interrupt handler + * @flags: registration flags + * @handle: driver data + * + * This function is similar to parport_register_device(), except + * that it locates a device by its number rather than by the port + * it is attached to. + * + * All parameters except for @devnum are the same as for + * parport_register_device(). The return value is the same as + * for parport_register_device(). + **/ + +struct pardevice *parport_open (int devnum, const char *name, + int (*pf) (void *), void (*kf) (void *), + void (*irqf) (int, void *, struct pt_regs *), + int flags, void *handle) +{ + struct daisydev *p = topology; + struct parport *port; + struct pardevice *dev; + int daisy; + + spin_lock(&topology_lock); + while (p && p->devnum != devnum) + p = p->next; + + if (!p) { + spin_unlock(&topology_lock); + return NULL; + } + + daisy = p->daisy; + port = parport_get_port(p->port); + spin_unlock(&topology_lock); + + dev = parport_register_device (port, name, pf, kf, + irqf, flags, handle); + parport_put_port(port); + if (!dev) + return NULL; + + dev->daisy = daisy; + + /* Check that there really is a device to select. */ + if (daisy >= 0) { + int selected; + parport_claim_or_block (dev); + selected = port->daisy; + parport_release (dev); + + if (selected != port->daisy) { + /* No corresponding device. */ + parport_unregister_device (dev); + return NULL; + } + } + + return dev; +} + +/** + * parport_close - close a device opened with parport_open() + * @dev: device to close + * + * This is to parport_open() as parport_unregister_device() is to + * parport_register_device(). + **/ + +void parport_close (struct pardevice *dev) +{ + parport_unregister_device (dev); +} + +/** + * parport_device_num - convert device coordinates + * @parport: parallel port number + * @mux: multiplexor port number (-1 for no multiplexor) + * @daisy: daisy chain address (-1 for no daisy chain address) + * + * This tries to locate a device on the given parallel port, + * multiplexor port and daisy chain address, and returns its + * device number or -NXIO if no device with those coordinates + * exists. + **/ + +int parport_device_num (int parport, int mux, int daisy) +{ + int res = -ENXIO; + struct daisydev *dev; + + spin_lock(&topology_lock); + dev = topology; + while (dev && dev->port->portnum != parport && + dev->port->muxport != mux && dev->daisy != daisy) + dev = dev->next; + if (dev) + res = dev->devnum; + spin_unlock(&topology_lock); + + return res; +} + +/* Send a daisy-chain-style CPP command packet. */ +static int cpp_daisy (struct parport *port, int cmd) +{ + unsigned char s; + + parport_data_forward (port); + parport_write_data (port, 0xaa); udelay (2); + parport_write_data (port, 0x55); udelay (2); + parport_write_data (port, 0x00); udelay (2); + parport_write_data (port, 0xff); udelay (2); + s = parport_read_status (port) & (PARPORT_STATUS_BUSY + | PARPORT_STATUS_PAPEROUT + | PARPORT_STATUS_SELECT + | PARPORT_STATUS_ERROR); + if (s != (PARPORT_STATUS_BUSY + | PARPORT_STATUS_PAPEROUT + | PARPORT_STATUS_SELECT + | PARPORT_STATUS_ERROR)) { + DPRINTK (KERN_DEBUG "%s: cpp_daisy: aa5500ff(%02x)\n", + port->name, s); + return -ENXIO; + } + + parport_write_data (port, 0x87); udelay (2); + s = parport_read_status (port) & (PARPORT_STATUS_BUSY + | PARPORT_STATUS_PAPEROUT + | PARPORT_STATUS_SELECT + | PARPORT_STATUS_ERROR); + if (s != (PARPORT_STATUS_SELECT | PARPORT_STATUS_ERROR)) { + DPRINTK (KERN_DEBUG "%s: cpp_daisy: aa5500ff87(%02x)\n", + port->name, s); + return -ENXIO; + } + + parport_write_data (port, 0x78); udelay (2); + parport_write_data (port, cmd); udelay (2); + parport_frob_control (port, + PARPORT_CONTROL_STROBE, + PARPORT_CONTROL_STROBE); + udelay (1); + parport_frob_control (port, PARPORT_CONTROL_STROBE, 0); + udelay (1); + s = parport_read_status (port); + parport_write_data (port, 0xff); udelay (2); + + return s; +} + +/* Send a mux-style CPP command packet. */ +static int cpp_mux (struct parport *port, int cmd) +{ + unsigned char s; + int rc; + + parport_data_forward (port); + parport_write_data (port, 0xaa); udelay (2); + parport_write_data (port, 0x55); udelay (2); + parport_write_data (port, 0xf0); udelay (2); + parport_write_data (port, 0x0f); udelay (2); + parport_write_data (port, 0x52); udelay (2); + parport_write_data (port, 0xad); udelay (2); + parport_write_data (port, cmd); udelay (2); + + s = parport_read_status (port); + if (!(s & PARPORT_STATUS_ACK)) { + DPRINTK (KERN_DEBUG "%s: cpp_mux: aa55f00f52ad%02x(%02x)\n", + port->name, cmd, s); + return -EIO; + } + + rc = (((s & PARPORT_STATUS_SELECT ? 1 : 0) << 0) | + ((s & PARPORT_STATUS_PAPEROUT ? 1 : 0) << 1) | + ((s & PARPORT_STATUS_BUSY ? 0 : 1) << 2) | + ((s & PARPORT_STATUS_ERROR ? 0 : 1) << 3)); + + return rc; +} + +void parport_daisy_deselect_all (struct parport *port) +{ + cpp_daisy (port, 0x30); +} + +int parport_daisy_select (struct parport *port, int daisy, int mode) +{ + switch (mode) + { + // For these modes we should switch to EPP mode: + case IEEE1284_MODE_EPP: + case IEEE1284_MODE_EPPSL: + case IEEE1284_MODE_EPPSWE: + return (cpp_daisy (port, 0x20 + daisy) & + PARPORT_STATUS_ERROR); + + // For these modes we should switch to ECP mode: + case IEEE1284_MODE_ECP: + case IEEE1284_MODE_ECPRLE: + case IEEE1284_MODE_ECPSWE: + return (cpp_daisy (port, 0xd0 + daisy) & + PARPORT_STATUS_ERROR); + + // Nothing was told for BECP in Daisy chain specification. + // May be it's wise to use ECP? + case IEEE1284_MODE_BECP: + // Others use compat mode + case IEEE1284_MODE_NIBBLE: + case IEEE1284_MODE_BYTE: + case IEEE1284_MODE_COMPAT: + default: + return (cpp_daisy (port, 0xe0 + daisy) & + PARPORT_STATUS_ERROR); + } +} + +static int mux_present (struct parport *port) +{ + return cpp_mux (port, 0x51) == 3; +} + +static int num_mux_ports (struct parport *port) +{ + return cpp_mux (port, 0x58); +} + +static int select_port (struct parport *port) +{ + int muxport = port->muxport; + return cpp_mux (port, 0x60 + muxport) == muxport; +} + +static int assign_addrs (struct parport *port) +{ + unsigned char s, last_dev; + unsigned char daisy; + int thisdev = numdevs; + int detected; + char *deviceid; + + parport_data_forward (port); + parport_write_data (port, 0xaa); udelay (2); + parport_write_data (port, 0x55); udelay (2); + parport_write_data (port, 0x00); udelay (2); + parport_write_data (port, 0xff); udelay (2); + s = parport_read_status (port) & (PARPORT_STATUS_BUSY + | PARPORT_STATUS_PAPEROUT + | PARPORT_STATUS_SELECT + | PARPORT_STATUS_ERROR); + if (s != (PARPORT_STATUS_BUSY + | PARPORT_STATUS_PAPEROUT + | PARPORT_STATUS_SELECT + | PARPORT_STATUS_ERROR)) { + DPRINTK (KERN_DEBUG "%s: assign_addrs: aa5500ff(%02x)\n", + port->name, s); + return 0; + } + + parport_write_data (port, 0x87); udelay (2); + s = parport_read_status (port) & (PARPORT_STATUS_BUSY + | PARPORT_STATUS_PAPEROUT + | PARPORT_STATUS_SELECT + | PARPORT_STATUS_ERROR); + if (s != (PARPORT_STATUS_SELECT | PARPORT_STATUS_ERROR)) { + DPRINTK (KERN_DEBUG "%s: assign_addrs: aa5500ff87(%02x)\n", + port->name, s); + return 0; + } + + parport_write_data (port, 0x78); udelay (2); + last_dev = 0; /* We've just been speaking to a device, so we + know there must be at least _one_ out there. */ + + for (daisy = 0; daisy < 4; daisy++) { + parport_write_data (port, daisy); + udelay (2); + parport_frob_control (port, + PARPORT_CONTROL_STROBE, + PARPORT_CONTROL_STROBE); + udelay (1); + parport_frob_control (port, PARPORT_CONTROL_STROBE, 0); + udelay (1); + + if (last_dev) + /* No more devices. */ + break; + + last_dev = !(parport_read_status (port) + & PARPORT_STATUS_BUSY); + + add_dev (numdevs++, port, daisy); + } + + parport_write_data (port, 0xff); udelay (2); + detected = numdevs - thisdev; + DPRINTK (KERN_DEBUG "%s: Found %d daisy-chained devices\n", port->name, + detected); + + /* Ask the new devices to introduce themselves. */ + deviceid = kmalloc (1000, GFP_KERNEL); + if (!deviceid) return 0; + + for (daisy = 0; thisdev < numdevs; thisdev++, daisy++) + parport_device_id (thisdev, deviceid, 1000); + + kfree (deviceid); + return detected; +} |