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-rw-r--r--drivers/parport/probe.c279
1 files changed, 279 insertions, 0 deletions
diff --git a/drivers/parport/probe.c b/drivers/parport/probe.c
new file mode 100644
index 000000000..7e6d713fa
--- /dev/null
+++ b/drivers/parport/probe.c
@@ -0,0 +1,279 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Parallel port device probing code
+ *
+ * Authors: Carsten Gross, carsten@sol.wohnheim.uni-ulm.de
+ * Philip Blundell <philb@gnu.org>
+ */
+
+#include <linux/module.h>
+#include <linux/parport.h>
+#include <linux/ctype.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+
+static const struct {
+ const char *token;
+ const char *descr;
+} classes[] = {
+ { "", "Legacy device" },
+ { "PRINTER", "Printer" },
+ { "MODEM", "Modem" },
+ { "NET", "Network device" },
+ { "HDC", "Hard disk" },
+ { "PCMCIA", "PCMCIA" },
+ { "MEDIA", "Multimedia device" },
+ { "FDC", "Floppy disk" },
+ { "PORTS", "Ports" },
+ { "SCANNER", "Scanner" },
+ { "DIGICAM", "Digital camera" },
+ { "", "Unknown device" },
+ { "", "Unspecified" },
+ { "SCSIADAPTER", "SCSI adapter" },
+ { NULL, NULL }
+};
+
+static void pretty_print(struct parport *port, int device)
+{
+ struct parport_device_info *info = &port->probe_info[device + 1];
+
+ pr_info("%s", port->name);
+
+ if (device >= 0)
+ pr_cont(" (addr %d)", device);
+
+ pr_cont(": %s", classes[info->class].descr);
+ if (info->class)
+ pr_cont(", %s %s", info->mfr, info->model);
+
+ pr_cont("\n");
+}
+
+static void parse_data(struct parport *port, int device, char *str)
+{
+ char *txt = kmalloc(strlen(str)+1, GFP_KERNEL);
+ char *p = txt, *q;
+ int guessed_class = PARPORT_CLASS_UNSPEC;
+ struct parport_device_info *info = &port->probe_info[device + 1];
+
+ if (!txt) {
+ pr_warn("%s probe: memory squeeze\n", port->name);
+ return;
+ }
+ strcpy(txt, str);
+ while (p) {
+ char *sep;
+ q = strchr(p, ';');
+ if (q) *q = 0;
+ sep = strchr(p, ':');
+ if (sep) {
+ char *u;
+ *(sep++) = 0;
+ /* Get rid of trailing blanks */
+ u = sep + strlen (sep) - 1;
+ while (u >= p && *u == ' ')
+ *u-- = '\0';
+ u = p;
+ while (*u) {
+ *u = toupper(*u);
+ u++;
+ }
+ if (!strcmp(p, "MFG") || !strcmp(p, "MANUFACTURER")) {
+ kfree(info->mfr);
+ info->mfr = kstrdup(sep, GFP_KERNEL);
+ } else if (!strcmp(p, "MDL") || !strcmp(p, "MODEL")) {
+ kfree(info->model);
+ info->model = kstrdup(sep, GFP_KERNEL);
+ } else if (!strcmp(p, "CLS") || !strcmp(p, "CLASS")) {
+ int i;
+
+ kfree(info->class_name);
+ info->class_name = kstrdup(sep, GFP_KERNEL);
+ for (u = sep; *u; u++)
+ *u = toupper(*u);
+ for (i = 0; classes[i].token; i++) {
+ if (!strcmp(classes[i].token, sep)) {
+ info->class = i;
+ goto rock_on;
+ }
+ }
+ pr_warn("%s probe: warning, class '%s' not understood\n",
+ port->name, sep);
+ info->class = PARPORT_CLASS_OTHER;
+ } else if (!strcmp(p, "CMD") ||
+ !strcmp(p, "COMMAND SET")) {
+ kfree(info->cmdset);
+ info->cmdset = kstrdup(sep, GFP_KERNEL);
+ /* if it speaks printer language, it's
+ probably a printer */
+ if (strstr(sep, "PJL") || strstr(sep, "PCL"))
+ guessed_class = PARPORT_CLASS_PRINTER;
+ } else if (!strcmp(p, "DES") || !strcmp(p, "DESCRIPTION")) {
+ kfree(info->description);
+ info->description = kstrdup(sep, GFP_KERNEL);
+ }
+ }
+ rock_on:
+ if (q)
+ p = q + 1;
+ else
+ p = NULL;
+ }
+
+ /* If the device didn't tell us its class, maybe we have managed to
+ guess one from the things it did say. */
+ if (info->class == PARPORT_CLASS_UNSPEC)
+ info->class = guessed_class;
+
+ pretty_print (port, device);
+
+ kfree(txt);
+}
+
+/* Read up to count-1 bytes of device id. Terminate buffer with
+ * '\0'. Buffer begins with two Device ID length bytes as given by
+ * device. */
+static ssize_t parport_read_device_id (struct parport *port, char *buffer,
+ size_t count)
+{
+ unsigned char length[2];
+ unsigned lelen, belen;
+ size_t idlens[4];
+ unsigned numidlens;
+ unsigned current_idlen;
+ ssize_t retval;
+ size_t len;
+
+ /* First two bytes are MSB,LSB of inclusive length. */
+ retval = parport_read (port, length, 2);
+
+ if (retval < 0)
+ return retval;
+ if (retval != 2)
+ return -EIO;
+
+ if (count < 2)
+ return 0;
+ memcpy(buffer, length, 2);
+ len = 2;
+
+ /* Some devices wrongly send LE length, and some send it two
+ * bytes short. Construct a sorted array of lengths to try. */
+ belen = (length[0] << 8) + length[1];
+ lelen = (length[1] << 8) + length[0];
+ idlens[0] = min(belen, lelen);
+ idlens[1] = idlens[0]+2;
+ if (belen != lelen) {
+ int off = 2;
+ /* Don't try lengths of 0x100 and 0x200 as 1 and 2 */
+ if (idlens[0] <= 2)
+ off = 0;
+ idlens[off] = max(belen, lelen);
+ idlens[off+1] = idlens[off]+2;
+ numidlens = off+2;
+ }
+ else {
+ /* Some devices don't truly implement Device ID, but
+ * just return constant nibble forever. This catches
+ * also those cases. */
+ if (idlens[0] == 0 || idlens[0] > 0xFFF) {
+ printk(KERN_DEBUG "%s: reported broken Device ID length of %#zX bytes\n",
+ port->name, idlens[0]);
+ return -EIO;
+ }
+ numidlens = 2;
+ }
+
+ /* Try to respect the given ID length despite all the bugs in
+ * the ID length. Read according to shortest possible ID
+ * first. */
+ for (current_idlen = 0; current_idlen < numidlens; ++current_idlen) {
+ size_t idlen = idlens[current_idlen];
+ if (idlen+1 >= count)
+ break;
+
+ retval = parport_read (port, buffer+len, idlen-len);
+
+ if (retval < 0)
+ return retval;
+ len += retval;
+
+ if (port->physport->ieee1284.phase != IEEE1284_PH_HBUSY_DAVAIL) {
+ if (belen != len) {
+ printk(KERN_DEBUG "%s: Device ID was %zd bytes while device told it would be %d bytes\n",
+ port->name, len, belen);
+ }
+ goto done;
+ }
+
+ /* This might end reading the Device ID too
+ * soon. Hopefully the needed fields were already in
+ * the first 256 bytes or so that we must have read so
+ * far. */
+ if (buffer[len-1] == ';') {
+ printk(KERN_DEBUG "%s: Device ID reading stopped before device told data not available. Current idlen %u of %u, len bytes %02X %02X\n",
+ port->name, current_idlen, numidlens,
+ length[0], length[1]);
+ goto done;
+ }
+ }
+ if (current_idlen < numidlens) {
+ /* Buffer not large enough, read to end of buffer. */
+ size_t idlen, len2;
+ if (len+1 < count) {
+ retval = parport_read (port, buffer+len, count-len-1);
+ if (retval < 0)
+ return retval;
+ len += retval;
+ }
+ /* Read the whole ID since some devices would not
+ * otherwise give back the Device ID from beginning
+ * next time when asked. */
+ idlen = idlens[current_idlen];
+ len2 = len;
+ while(len2 < idlen && retval > 0) {
+ char tmp[4];
+ retval = parport_read (port, tmp,
+ min(sizeof tmp, idlen-len2));
+ if (retval < 0)
+ return retval;
+ len2 += retval;
+ }
+ }
+ /* In addition, there are broken devices out there that don't
+ even finish off with a semi-colon. We do not need to care
+ about those at this time. */
+ done:
+ buffer[len] = '\0';
+ return len;
+}
+
+/* Get Std 1284 Device ID. */
+ssize_t parport_device_id (int devnum, char *buffer, size_t count)
+{
+ ssize_t retval = -ENXIO;
+ struct pardevice *dev = parport_open(devnum, daisy_dev_name);
+ if (!dev)
+ return -ENXIO;
+
+ parport_claim_or_block (dev);
+
+ /* Negotiate to compatibility mode, and then to device ID
+ * mode. (This so that we start form beginning of device ID if
+ * already in device ID mode.) */
+ parport_negotiate (dev->port, IEEE1284_MODE_COMPAT);
+ retval = parport_negotiate (dev->port,
+ IEEE1284_MODE_NIBBLE | IEEE1284_DEVICEID);
+
+ if (!retval) {
+ retval = parport_read_device_id (dev->port, buffer, count);
+ parport_negotiate (dev->port, IEEE1284_MODE_COMPAT);
+ if (retval > 2)
+ parse_data (dev->port, dev->daisy, buffer+2);
+ }
+
+ parport_release (dev);
+ parport_close (dev);
+ return retval;
+}
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