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-rw-r--r--drivers/parport/daisy.c482
1 files changed, 482 insertions, 0 deletions
diff --git a/drivers/parport/daisy.c b/drivers/parport/daisy.c
new file mode 100644
index 000000000..5bed17f68
--- /dev/null
+++ b/drivers/parport/daisy.c
@@ -0,0 +1,482 @@
+/*
+ * 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.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;
+}
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