/* * 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(1024, GFP_KERNEL); if (deviceid) { if (parport_device_id(numdevs - 1, deviceid, 1024) > 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 * * 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) { 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, NULL, NULL, NULL, 0, NULL); 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 != 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); } /* 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); s = parport_read_status(port); parport_frob_control(port, PARPORT_CONTROL_STROBE, 0); udelay(1); 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; 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); s = parport_read_status(port); for (daisy = 0; (s & (PARPORT_STATUS_PAPEROUT|PARPORT_STATUS_SELECT)) == (PARPORT_STATUS_PAPEROUT|PARPORT_STATUS_SELECT) && 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); add_dev(numdevs++, port, daisy); /* See if this device thought it was the last in the * chain. */ if (!(s & PARPORT_STATUS_BUSY)) break; /* We are seeing pass through status now. We see last_dev from next device or if last_dev does not work status lines from some non-daisy chain device. */ s = parport_read_status(port); } 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(1024, GFP_KERNEL); if (!deviceid) return 0; for (daisy = 0; thisdev < numdevs; thisdev++, daisy++) parport_device_id(thisdev, deviceid, 1024); kfree(deviceid); return detected; }