diff options
Diffstat (limited to 'drivers/parport/daisy.c')
| -rw-r--r-- | drivers/parport/daisy.c | 507 |
1 files changed, 507 insertions, 0 deletions
diff --git a/drivers/parport/daisy.c b/drivers/parport/daisy.c new file mode 100644 index 0000000000..6d78ec3a76 --- /dev/null +++ b/drivers/parport/daisy.c @@ -0,0 +1,507 @@ +/* + * 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/slab.h> +#include <linux/sched/signal.h> + +#include <asm/current.h> +#include <linux/uaccess.h> + +#undef DEBUG + +static struct daisydev { + struct daisydev *next; + struct parport *port; + int daisy; + int devnum; +} *topology = NULL; +static DEFINE_SPINLOCK(topology_lock); + +static int numdevs; +static bool daisy_init_done; + +/* 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; +} + +static int daisy_drv_probe(struct pardevice *par_dev) +{ + struct device_driver *drv = par_dev->dev.driver; + + if (strcmp(drv->name, "daisy_drv")) + return -ENODEV; + if (strcmp(par_dev->name, daisy_dev_name)) + return -ENODEV; + + return 0; +} + +static struct parport_driver daisy_driver = { + .name = "daisy_drv", + .probe = daisy_drv_probe, + .devmodel = true, +}; + +/* 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; + + if (!daisy_init_done) { + /* + * flag should be marked true first as + * parport_register_driver() might try to load the low + * level driver which will lead to announcing new ports + * and which will again come back here at + * parport_daisy_init() + */ + daisy_init_done = true; + i = parport_register_driver(&daisy_driver); + if (i) { + pr_err("daisy registration failed\n"); + daisy_init_done = false; + return i; + } + } + +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; + pr_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; + } + + pr_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 pardev_cb par_cb; + struct parport *port; + struct pardevice *dev; + int daisy; + + memset(&par_cb, 0, sizeof(par_cb)); + 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_dev_model(port, name, &par_cb, devnum); + 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)) { + pr_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)) { + pr_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)) { + pr_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)) { + pr_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)) { + pr_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; + pr_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; +} |