FreeBSD/Linux Kernel Cross Reference
sys/i386/isa/pnp.c

     /*
      * Copyright (c) 1996, Sujal M. Patel
      * All rights reserved.
      *
      * Redistribution and use in source and binary forms, with or without
      * modification, are permitted provided that the following conditions
      * are met:
      * 1. Redistributions of source code must retain the above copyright
      *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     *
     * $FreeBSD$
     */
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/linker_set.h>
    #include <sys/malloc.h>
    #include <sys/interrupt.h>
    #include <machine/clock.h>
    #include <machine/md_var.h>
    
    #include <i386/isa/icu.h>
    #include <i386/isa/isa_device.h>
    #include <i386/isa/pnp.h>
    
    typedef struct _pnp_id {
            u_long vendor_id;
            u_long serial;
            u_char checksum;
            u_long comp_id;
    } pnp_id;
    
    static int num_pnp_cards = 0;
    pnp_id pnp_devices[MAX_PNP_CARDS];
    struct pnp_dlist_node *pnp_device_list;
    static struct pnp_dlist_node **pnp_device_list_last_ptr;
    
    /*
     * these entries are initialized using the autoconfig menu
     * The struct is invalid (and must be initialized) if the first
     * CSN is zero. The init code fills invalid entries with CSN 255
     * which is not a supported value.
     */
    
    struct pnp_cinfo pnp_ldn_overrides[MAX_PNP_LDN] = { { 0 } };
    
    /*
     * the following is a flag which tells if the data is valid.
     */
    static int doing_pnp_probe = 0 ;
    static int current_csn ;
    static int current_pnp_id ;
    static int current_pnp_serial ;
    
    /*
     * the following block is an example on what is needed for
     * a PnP device driver.
     */
    static  char*   nullpnp_probe(u_long csn, u_long vendor_id);
    static  void    nullpnp_attach(u_long csn, u_long vendor_id, char *name,
        struct isa_device *dev);
    static  u_long  nullpnp_count = 0 ;
    
    static struct pnp_device nullpnp_device = {
        "goodpnp",
        nullpnp_probe,
        nullpnp_attach,
        &nullpnp_count,
        NULL /* imask */
    };
    
    DATA_SET (pnpdevice_set, nullpnp_device);
    
    static char*
    nullpnp_probe(u_long tag, u_long type)
    {
        if (bootverbose)
                printf("Called nullpnp_probe with tag 0x%08lx, type 0x%08lx\n",
                        tag, type);
        return NULL;
    }
    
    static void
    nullpnp_attach(u_long csn, u_long vend_id, char *name,
           struct isa_device *dev)
   {
       printf("nullpnp_attach: csn %ld, vend_id 0x%08lx name %s unit %d\n",
               csn, vend_id, name, dev->id_unit);
       return;
   }
   
   /* The READ_DATA port that we are using currently */
   static int pnp_rd_port;
   
   static void   pnp_send_Initiation_LFSR (void);
   static int    pnp_get_serial (pnp_id *p);
   static void   config_pnp_device (pnp_id *p, int csn);
   static int    pnp_isolation_protocol (void);
   
   void
   pnp_write(int d, u_char r)
   {
       outb (_PNP_ADDRESS, d);
       outb (_PNP_WRITE_DATA, r);
   }
   
   u_char
   pnp_read(int d)
   {
       outb (_PNP_ADDRESS, d);
       return (inb(3 | (pnp_rd_port <<2)));
   }
   
   /*
    * Send Initiation LFSR as described in "Plug and Play ISA Specification",
    * Intel May 94.
    */
   static void
   pnp_send_Initiation_LFSR()
   {
       int cur, i;
   
       /* Reset the LSFR */
       outb(_PNP_ADDRESS, 0);
       outb(_PNP_ADDRESS, 0); /* yes, we do need it twice! */
   
       cur = 0x6a;
       outb(_PNP_ADDRESS, cur);
   
       for (i = 1; i < 32; i++) {
           cur = (cur >> 1) | (((cur ^ (cur >> 1)) << 7) & 0xff);
           outb(_PNP_ADDRESS, cur);
       }
   }
   
   
   /*
    * Get the device's serial number.  Returns 1 if the serial is valid.
    */
   static int
   pnp_get_serial(pnp_id *p)
   {
       int i, bit, valid = 0, sum = 0x6a;
       u_char *data = (u_char *)p;
   
       bzero(data, sizeof(char) * 9);
       outb(_PNP_ADDRESS, SERIAL_ISOLATION);
       for (i = 0; i < 72; i++) {
           bit = inb((pnp_rd_port << 2) | 0x3) == 0x55;
           DELAY(250);     /* Delay 250 usec */
   
           /* Can't Short Circuit the next evaluation, so 'and' is last */
           bit = (inb((pnp_rd_port << 2) | 0x3) == 0xaa) && bit;
           DELAY(250);     /* Delay 250 usec */
   
           valid = valid || bit;
   
           if (i < 64)
               sum = (sum >> 1) |
                   (((sum ^ (sum >> 1) ^ bit) << 7) & 0xff);
   
           data[i / 8] = (data[i / 8] >> 1) | (bit ? 0x80 : 0);
       }
   
       valid = valid && (data[8] == sum);
   
       return valid;
   }
   
   /*
    * Fill's the buffer with resource info from the device.
    * Returns 0 if the device fails to report
    */
   static int
   pnp_get_resource_info(u_char *buffer, int len)
   {
       int i, j;
       u_char temp;
   
       for (i = 0; i < len; i++) {
           outb(_PNP_ADDRESS, STATUS);
           for (j = 0; j < 100; j++) {
               if ((inb((pnp_rd_port << 2) | 0x3)) & 0x1)
                   break;
               DELAY(1);
           }
           if (j == 100) {
               printf("PnP device failed to report resource data\n");
               return 0;
           }
           outb(_PNP_ADDRESS, RESOURCE_DATA);
           temp = inb((pnp_rd_port << 2) | 0x3);
           if (buffer != NULL)
               buffer[i] = temp;
       }
       return 1;
   }
   
   /*
    * read_pnp_parms loads pnp parameters from the currently selected
    * device into the struct pnp_cinfo parameter passed.
    * The second argument specifies the Logical Device to use.
    */
   int
   read_pnp_parms(struct pnp_cinfo *d, int ldn)
   {
       int i ;
   
       if (doing_pnp_probe == 0 || d == NULL)
           return 0 ;      /* fail */
   
       bzero(d, sizeof(struct pnp_cinfo));
       d->vendor_id = current_pnp_id ;
       d->serial = current_pnp_serial ;
   
       d->csn = current_csn ;
       d->ldn = ldn ;      /* XXX this should be different ... */
       pnp_write (SET_LDN, ldn );
       i = pnp_read(SET_LDN) ;
       if (i != ldn) {
           printf("Warning: LDN %d does not exist\n", ldn);
       }
       for (i = 0; i < 8; i++) {
           d->port[i] = pnp_read(IO_CONFIG_BASE + i * 2) << 8 ;
           d->port[i] |= pnp_read(IO_CONFIG_BASE + i * 2 + 1);
   
           if (i < 4) {
               d->mem[i].base = pnp_read (MEM_CONFIG + i*8) << 16 ;
               d->mem[i].base |= pnp_read (MEM_CONFIG + i*8 + 1) << 8 ;
               d->mem[i].control = pnp_read (MEM_CONFIG + i*8 + 2) ;
               d->mem[i].range = pnp_read (MEM_CONFIG + i*8 + 3) << 16 ;
               d->mem[i].range |= pnp_read (MEM_CONFIG + i*8 + 4) << 8 ;
           }
           if (i < 2) {
               d->irq[i] = pnp_read(IRQ_CONFIG + i * 2);
               d->irq_type[i] = pnp_read(IRQ_CONFIG + 1 + i * 2);
               d->drq[i] = pnp_read(DRQ_CONFIG + i);
           }
       }
       d->enable = pnp_read(ACTIVATE);
       for (i = 0 ; i < MAX_PNP_LDN; i++) {
           if (pnp_ldn_overrides[i].csn == d->csn &&
                   pnp_ldn_overrides[i].ldn == ldn) {
               d->flags = pnp_ldn_overrides[i].flags ;
               d->override = pnp_ldn_overrides[i].override ;
               break ;
           }
       }
       if (bootverbose)
           printf("port 0x%04x 0x%04x 0x%04x 0x%04x irq %d:%d drq %d:%d en %d\n",
               d->port[0], d->port[1], d->port[2], d->port[3],
               d->irq[0], d->irq[1],
               d->drq[0], d->drq[1],
               d->enable);
       return 1 ; /* success */
   }
   
   /*
    * write_pnp_parms initializes a logical device with the parms
    * in d, and then activates the board if the last parameter is 1.
    */
   
   int
   write_pnp_parms(struct pnp_cinfo *d, int ldn)
   {
       int i, empty = -1 ;
   
       /*
        * some safety checks first.
        */
       if (doing_pnp_probe == 0 || d==NULL || d->vendor_id != current_pnp_id)
           return 0 ;      /* fail */
   
       pnp_write (SET_LDN, ldn );
       i = pnp_read(SET_LDN) ;
       if (i != ldn) {
           printf("Warning: LDN %d does not exist\n", ldn);
       }
       for (i = 0; i < 8; i++) {
           pnp_write(IO_CONFIG_BASE + i * 2, d->port[i] >> 8 );
           pnp_write(IO_CONFIG_BASE + i * 2 + 1, d->port[i] & 0xff );
       }
       for (i = 0; i < 4; i++) {
           pnp_write(MEM_CONFIG + i*8, (d->mem[i].base >> 16) & 0xff );
           pnp_write(MEM_CONFIG + i*8+1, (d->mem[i].base >> 8) & 0xff );
           pnp_write(MEM_CONFIG + i*8+2, d->mem[i].control & 0xff );
           pnp_write(MEM_CONFIG + i*8+3, (d->mem[i].range >> 16) & 0xff );
           pnp_write(MEM_CONFIG + i*8+4, (d->mem[i].range >> 8) & 0xff );
       }
       for (i = 0; i < 2; i++) {
           pnp_write(IRQ_CONFIG + i*2    , d->irq[i] );
           pnp_write(IRQ_CONFIG + i*2 + 1, d->irq_type[i] );
           pnp_write(DRQ_CONFIG + i, d->drq[i] );
       }
       /*
        * store parameters read into the current kernel
        * so manual editing next time is easier
        */
       for (i = 0 ; i < MAX_PNP_LDN; i++) {
           if (pnp_ldn_overrides[i].csn == d->csn &&
                   pnp_ldn_overrides[i].ldn == ldn) {
               d->flags = pnp_ldn_overrides[i].flags ;
               pnp_ldn_overrides[i] = *d ;
               break ;
           } else if (pnp_ldn_overrides[i].csn < 1 ||
                   pnp_ldn_overrides[i].csn == 255)
               empty = i ;
       }
       if (i== MAX_PNP_LDN && empty != -1)
           pnp_ldn_overrides[empty] = *d;
   
       /*
        * Here should really perform the range check, and
        * return a failure if not successful.
        */
       pnp_write (IO_RANGE_CHECK, 0);
       DELAY(1000); /* XXX is it really necessary ? */
       pnp_write (ACTIVATE, d->enable ? 1 : 0);
       DELAY(1000); /* XXX is it really necessary ? */
       return 1 ;
   }
   
   /*
    * To finalize a card's initialization, and before accessing its
    * registers, we need to bring the card in WaitForKey. To this purpose,
    * we need to issue a WaitForKey command, which brings _all_ cards
    * in that state. So, before configuring the next board, we must also
    * sent the Init-Key to bring cards to the SLEEP state again.
    *
    * In fact, one could hope that cards respond to normal I/O accesses
    * even in the SLEEP state, which could be done by issuing a WAKE[0].
    * This seems to work on the CS4236, but not on the CS4232 on my Zappa
    * motherboard .
    */
   int
   enable_pnp_card()
   {
       /* the next wake should bring the card in WaitForKey ? */
       pnp_write (WAKE, 0);
       pnp_write(CONFIG_CONTROL, 0x02);    /* All cards in WaitForKey */
       DELAY(1000); /* XXX is it really necessary ? */
       return 1 ; /* success */
   }
   
   /*
    * Configure PnP devices. pnp_id is made of:
    *      4 bytes: board id (which can be printed as an ascii string);
    *      4 bytes: board serial number (often 0 or -1 ?)
    */
   
   static void
   config_pnp_device(pnp_id *p, int csn)
   {
       static struct pnp_dlist_node *nod = NULL;
       int i;
       u_char *data = (u_char *)p;
       u_char *comp = (u_char *)&p->comp_id;
   
       /* these are for autoconfigure a-la pci */
       struct pnp_device *dvp, **dvpp;
       char *name = NULL;
   
       printf("CSN %d Vendor ID: %c%c%c%02x%02x [0x%08lx] Serial 0x%08lx Comp ID: %c%c%c%02x%02x [0x%08lx]\n",
           csn,
           ((data[0] & 0x7c) >> 2) + '@',
           (((data[0] & 0x03) << 3) | ((data[1] & 0xe0) >> 5)) + '@',
           (data[1] & 0x1f) + '@', data[2], data[3],
           p->vendor_id, p->serial,
           ((comp[0] & 0x7c) >> 2) + '@',
           (((comp[0] & 0x03) << 3) | ((comp[1] & 0xe0) >> 5)) + '@',
           (comp[1] & 0x1f) + '@', comp[2], comp[3],
           p->comp_id);
   
       doing_pnp_probe = 1 ;
       current_csn = csn ;
       current_pnp_id = p->vendor_id ;
       current_pnp_serial = p->serial ;
   
       /*
        * use kernel table to override possible devices
        */
       for (i = 0 ; i < MAX_PNP_LDN; i++) {
           if (pnp_ldn_overrides[i].csn == csn &&
                   pnp_ldn_overrides[i].override == 1) {
               struct pnp_cinfo d;
               if (bootverbose)
                   printf("PnP: override config for CSN %d LDN %d "
                       "vend_id 0x%08x\n", csn, pnp_ldn_overrides[i].ldn,
                       current_pnp_id);
               /* next assignement is done otherwise read fails */
               d.vendor_id = current_pnp_id ;
               read_pnp_parms(&d, pnp_ldn_overrides[i].ldn);
               if (pnp_ldn_overrides[i].enable == 0) {
                   /* just disable ... */
                   d.enable = 0;
                   write_pnp_parms(&d, pnp_ldn_overrides[i].ldn);
               } else {
                   /* set all parameters */
                   /* next assignement is done otherwise write fails */
                   pnp_ldn_overrides[i].vendor_id = current_pnp_id ;
                   write_pnp_parms(&pnp_ldn_overrides[i],
                       pnp_ldn_overrides[i].ldn);
               }
           }
       }
   
       /* lookup device in ioconfiguration */
       dvpp = (struct pnp_device **)pnpdevice_set.ls_items;
       while ((dvp = *dvpp++)) {
           if (dvp->pd_probe) {
               if ( ((name = (*dvp->pd_probe)(csn, p->vendor_id)) && *name) ||
                   (p->comp_id &&
                       (name = (*dvp->pd_probe)(csn, p->comp_id))))
                   break;
           }
       }
       if (dvp && name && *name && dvp->pd_count) { /* found a matching device */
           int unit ;
   
           /* pnpcb->pnpcb_seen |= ( 1ul << csn ) ; */
   
           /* get and increment the unit */
           unit = (*dvp->pd_count)++;
   
           /*
            * now call the attach routine. The board has not been
            * configured yet, so better not access isa registers in
            * the attach routine until enable_pnp_card() has been done.
            */
           
           if (nod == NULL)
                   nod = malloc(sizeof(struct pnp_dlist_node), M_DEVBUF, M_NOWAIT);
           if (nod == NULL)
                   panic("malloc failed for PnP resource use");
           bzero(nod, sizeof(*nod));
           nod->pnp = dvp;
           nod->dev.id_unit = unit ;
           if (dvp->pd_attach)
               (*dvp->pd_attach) (csn, p->vendor_id, name, &(nod->dev));
           printf("%s%d (%s <%s> sn 0x%08lx)", nod->dev.id_driver &&
               nod->dev.id_driver->name ? nod->dev.id_driver->name : "unknown",
               unit, dvp->pd_name, name, p->serial);
           if (nod->dev.id_alive) {
               if (nod->dev.id_irq != 0 && nod->dev.id_intr != NULL) {
                   /* the board uses interrupts. Register it. */
                   if (dvp->imask)
                       INTRMASK( *(dvp->imask), nod->dev.id_irq );
                   register_intr(ffs(nod->dev.id_irq) - 1, nod->dev.id_id,
                       nod->dev.id_ri_flags, nod->dev.id_intr,
                       dvp->imask, nod->dev.id_unit);
                   INTREN(nod->dev.id_irq);
               }
               if (nod->dev.id_alive != 0) {
                   if (nod->dev.id_iobase == -1) 
                       printf(" at ?");
                   else {
                       printf(" at 0x%x", nod->dev.id_iobase);
                       if ((nod->dev.id_iobase + nod->dev.id_alive -1) !=
                           nod->dev.id_iobase) {
                           printf("-0x%x", nod->dev.id_iobase + nod->dev.id_alive
                               - 1);
                       }
                   }
               }
               if (nod->dev.id_irq)
                   printf(" irq %d", ffs(nod->dev.id_irq) - 1);
               if (nod->dev.id_drq != -1)
                   printf(" drq %d", nod->dev.id_drq);
               if (nod->dev.id_maddr)
                   printf(" maddr 0x%lx", kvtop(nod->dev.id_maddr));
               if (nod->dev.id_msize)
                   printf(" msize %d", nod->dev.id_msize);
               if (nod->dev.id_flags)
                   printf(" flags 0x%x", nod->dev.id_flags);
   #ifdef PC98
               printf (" on isa");
   #else
               if (nod->dev.id_iobase && !(nod->dev.id_iobase & 0xf300)) {
                   printf(" on motherboard");
                   printf(" id %d", nod->dev.id_id);
               } else if (nod->dev.id_iobase >= 0x1000 &&
                   !(nod->dev.id_iobase & 0x300)) {
                   printf (" on eisa slot %d",
                       nod->dev.id_iobase >> 12);
               } else {
                   printf (" on isa");
               }
   #endif
               printf("\n");
               if (pnp_device_list_last_ptr == NULL)
                   pnp_device_list = nod;
               else
                   *pnp_device_list_last_ptr = nod;
               pnp_device_list_last_ptr = &(nod->next);
               nod = NULL;
           } else
               printf(" failed to attach\n");
       }
       doing_pnp_probe = 0 ;
   }
   
   /*
    * Scan Resource Data for Compatible Device ID.
    *
    * This function exits as soon as it gets a Compatible Device ID, an error
    * reading *ANY* Resource Data or ir reaches the end of Resource Data.
    * In the first case the return value will be TRUE, FALSE otherwise.
    */
   static int
   pnp_scan_resdata(pnp_id *p, int csn)
   {
       u_char tag, resinfo[8];
       int large_len, scanning = 1024, retval = FALSE;
   
       while (scanning-- > 0 && pnp_get_resource_info(&tag, 1)) {
           if (PNP_RES_TYPE(tag) == 0) {
               /* Small resource */
               switch (PNP_SRES_NUM(tag)) {
                   case COMP_DEVICE_ID:
                       /* Got a compatible device id resource */
                       if (pnp_get_resource_info(resinfo, PNP_SRES_LEN(tag))) {
                           bcopy(resinfo, &p->comp_id, 4);
                           retval = TRUE;
                           if (bootverbose)
                               printf("PnP: CSN %d COMP_DEVICE_ID = 0x%08lx\n", csn, p->comp_id);
                       }
                       /*
                        * We found what we were looking for, or got an error from
                        * pnp_get_resource, => stop scanning (FALLTHROUGH)
                        */
                   case END_TAG:
                       scanning = 0;
                       break;
                   default:
                       /* Skip this resource */
                       if (pnp_get_resource_info(NULL, PNP_SRES_LEN(tag)) == 0)
                           scanning = 0;
                       break;
               }
           } else
               /* Large resource, skip it */
               if (!(pnp_get_resource_info((u_char *)&large_len, 2) && pnp_get_resource_info(NULL, large_len)))
                   scanning = 0;
       }
   
       return retval;
   }
   
   /*
    * Run the isolation protocol. Use pnp_rd_port as the READ_DATA port
    * value (caller should try multiple READ_DATA locations before giving
    * up). Upon exiting, all cards are aware that they should use
    * pnp_rd_port as the READ_DATA port.
    *
    * In the first pass, a csn is assigned to each board and pnp_id's
    * are saved to an array, pnp_devices. In the second pass, each
    * card is woken up and the device configuration is called.
    */
   static int
   pnp_isolation_protocol()
   {
       int csn;
   
       pnp_send_Initiation_LFSR();
   
       pnp_write(CONFIG_CONTROL, 0x04);    /* Reset CSN for All Cards */
   
       for (csn = 1; (csn < MAX_PNP_CARDS); csn++) {
           /* Wake up cards without a CSN */
           pnp_write(WAKE, 0);
           pnp_write(SET_RD_DATA, pnp_rd_port);
           outb(_PNP_ADDRESS, SERIAL_ISOLATION);
           DELAY(1000);    /* Delay 1 msec */
   
           if (pnp_get_serial( &(pnp_devices[csn-1]) ) ) {
               pnp_write(SET_CSN, csn);
               /* pnp_write(CONFIG_CONTROL, 2); */
               if (!pnp_scan_resdata(&(pnp_devices[csn-1]), csn))
                   pnp_devices[csn-1].comp_id = NULL;
           } else
               break;
       }
       num_pnp_cards = csn - 1;
       for (csn = 1; csn <= num_pnp_cards ; csn++) {
           /*
            * make sure cards are in SLEEP state
            */
           pnp_send_Initiation_LFSR();
           pnp_write(WAKE, csn);
           config_pnp_device( &(pnp_devices[csn-1]), csn);
           /*
            * Put all cards in WaitForKey, just in case the previous
            * attach routine forgot it.
            */
           pnp_write(CONFIG_CONTROL, 0x02);
           DELAY(1000); /* XXX is it really necessary ? */
       }
       return num_pnp_cards ;
   }
   
   
   /*
    * pnp_configure()
    *
    * autoconfiguration of pnp devices. This routine just runs the
    * isolation protocol over several ports, until one is successful.
    *
    * may be called more than once ?
    *
    */
   
   void
   pnp_configure()
   {
       int num_pnp_devs;
   
       if (pnp_ldn_overrides[0].csn == 0) {
           if (bootverbose)
               printf("Initializing PnP override table\n");
           bzero (pnp_ldn_overrides, sizeof(pnp_ldn_overrides));
           pnp_ldn_overrides[0].csn = 255 ;
       }
       printf("Probing for PnP devices:\n");
   
       /* Try various READ_DATA ports from 0x203-0x3ff */
       for (pnp_rd_port = 0x80; (pnp_rd_port < 0xff); pnp_rd_port += 0x10) {
           if (bootverbose)
               printf("Trying Read_Port at %x\n", (pnp_rd_port << 2) | 0x3);
   
           num_pnp_devs = pnp_isolation_protocol();
           if (num_pnp_devs)
               break;
       }
       if (!num_pnp_devs) {
           if (bootverbose)
               printf("No Plug-n-Play devices were found\n");
           return;
       }
   }

Cache object: 7b89c06af37147072b4e6f71faf348cc