xref: /openbmc/linux/drivers/mmc/host/Kconfig (revision 089a49b6)
1#
2# MMC/SD host controller drivers
3#
4
5comment "MMC/SD/SDIO Host Controller Drivers"
6
7config MMC_ARMMMCI
8	tristate "ARM AMBA Multimedia Card Interface support"
9	depends on ARM_AMBA
10	help
11	  This selects the ARM(R) AMBA(R) PrimeCell Multimedia Card
12	  Interface (PL180 and PL181) support.  If you have an ARM(R)
13	  platform with a Multimedia Card slot, say Y or M here.
14
15	  If unsure, say N.
16
17config MMC_PXA
18	tristate "Intel PXA25x/26x/27x Multimedia Card Interface support"
19	depends on ARCH_PXA
20	help
21	  This selects the Intel(R) PXA(R) Multimedia card Interface.
22	  If you have a PXA(R) platform with a Multimedia Card slot,
23	  say Y or M here.
24
25	  If unsure, say N.
26
27config MMC_SDHCI
28	tristate "Secure Digital Host Controller Interface support"
29	depends on HAS_DMA
30	help
31	  This selects the generic Secure Digital Host Controller Interface.
32	  It is used by manufacturers such as Texas Instruments(R), Ricoh(R)
33	  and Toshiba(R). Most controllers found in laptops are of this type.
34
35	  If you have a controller with this interface, say Y or M here. You
36	  also need to enable an appropriate bus interface.
37
38	  If unsure, say N.
39
40config MMC_SDHCI_IO_ACCESSORS
41	bool
42	depends on MMC_SDHCI
43	help
44	  This is silent Kconfig symbol that is selected by the drivers that
45	  need to overwrite SDHCI IO memory accessors.
46
47config MMC_SDHCI_BIG_ENDIAN_32BIT_BYTE_SWAPPER
48	bool
49	select MMC_SDHCI_IO_ACCESSORS
50	help
51	  This option is selected by drivers running on big endian hosts
52	  and performing I/O to a SDHCI controller through a bus that
53	  implements a hardware byte swapper using a 32-bit datum.
54	  This endian mapping mode is called "data invariance" and
55	  has the effect of scrambling the addresses and formats of data
56	  accessed in sizes other than the datum size.
57
58	  This is the case for the Freescale eSDHC and Nintendo Wii SDHCI.
59
60config MMC_SDHCI_PCI
61	tristate "SDHCI support on PCI bus"
62	depends on MMC_SDHCI && PCI
63	help
64	  This selects the PCI Secure Digital Host Controller Interface.
65	  Most controllers found today are PCI devices.
66
67	  If you have a controller with this interface, say Y or M here.
68
69	  If unsure, say N.
70
71config MMC_RICOH_MMC
72	bool "Ricoh MMC Controller Disabler"
73	depends on MMC_SDHCI_PCI
74	help
75	  This adds a pci quirk to disable Ricoh MMC Controller. This
76	  proprietary controller is unnecessary because the SDHCI driver
77	  supports MMC cards on the SD controller, but if it is not
78	  disabled, it will steal the MMC cards away - rendering them
79	  useless. It is safe to select this even if you don't
80	  have a Ricoh based card reader.
81
82	  If unsure, say Y.
83
84config MMC_SDHCI_ACPI
85	tristate "SDHCI support for ACPI enumerated SDHCI controllers"
86	depends on MMC_SDHCI && ACPI
87	help
88	  This selects support for ACPI enumerated SDHCI controllers,
89	  identified by ACPI Compatibility ID PNP0D40 or specific
90	  ACPI Hardware IDs.
91
92	  If you have a controller with this interface, say Y or M here.
93
94	  If unsure, say N.
95
96config MMC_SDHCI_PLTFM
97	tristate "SDHCI platform and OF driver helper"
98	depends on MMC_SDHCI
99	help
100	  This selects the common helper functions support for Secure Digital
101	  Host Controller Interface based platform and OF drivers.
102
103	  If you have a controller with this interface, say Y or M here.
104
105	  If unsure, say N.
106
107config MMC_SDHCI_OF_ESDHC
108	tristate "SDHCI OF support for the Freescale eSDHC controller"
109	depends on MMC_SDHCI_PLTFM
110	depends on PPC_OF
111	select MMC_SDHCI_BIG_ENDIAN_32BIT_BYTE_SWAPPER
112	help
113	  This selects the Freescale eSDHC controller support.
114
115	  If you have a controller with this interface, say Y or M here.
116
117	  If unsure, say N.
118
119config MMC_SDHCI_OF_HLWD
120	tristate "SDHCI OF support for the Nintendo Wii SDHCI controllers"
121	depends on MMC_SDHCI_PLTFM
122	depends on PPC_OF
123	select MMC_SDHCI_BIG_ENDIAN_32BIT_BYTE_SWAPPER
124	help
125	  This selects the Secure Digital Host Controller Interface (SDHCI)
126	  found in the "Hollywood" chipset of the Nintendo Wii video game
127	  console.
128
129	  If you have a controller with this interface, say Y or M here.
130
131	  If unsure, say N.
132
133config MMC_SDHCI_CNS3XXX
134	tristate "SDHCI support on the Cavium Networks CNS3xxx SoC"
135	depends on ARCH_CNS3XXX
136	depends on MMC_SDHCI_PLTFM
137	help
138	  This selects the SDHCI support for CNS3xxx System-on-Chip devices.
139
140	  If you have a controller with this interface, say Y or M here.
141
142	  If unsure, say N.
143
144config MMC_SDHCI_ESDHC_IMX
145	tristate "SDHCI support for the Freescale eSDHC/uSDHC i.MX controller"
146	depends on ARCH_MXC
147	depends on MMC_SDHCI_PLTFM
148	select MMC_SDHCI_IO_ACCESSORS
149	help
150	  This selects the Freescale eSDHC/uSDHC controller support
151	  found on i.MX25, i.MX35 i.MX5x and i.MX6x.
152
153	  If you have a controller with this interface, say Y or M here.
154
155	  If unsure, say N.
156
157config MMC_SDHCI_DOVE
158	tristate "SDHCI support on Marvell's Dove SoC"
159	depends on ARCH_DOVE
160	depends on MMC_SDHCI_PLTFM
161	select MMC_SDHCI_IO_ACCESSORS
162	help
163	  This selects the Secure Digital Host Controller Interface in
164	  Marvell's Dove SoC.
165
166	  If you have a controller with this interface, say Y or M here.
167
168	  If unsure, say N.
169
170config MMC_SDHCI_TEGRA
171	tristate "SDHCI platform support for the Tegra SD/MMC Controller"
172	depends on ARCH_TEGRA
173	depends on MMC_SDHCI_PLTFM
174	select MMC_SDHCI_IO_ACCESSORS
175	help
176	  This selects the Tegra SD/MMC controller. If you have a Tegra
177	  platform with SD or MMC devices, say Y or M here.
178
179	  If unsure, say N.
180
181config MMC_SDHCI_S3C
182	tristate "SDHCI support on Samsung S3C SoC"
183	depends on MMC_SDHCI && PLAT_SAMSUNG
184	help
185	  This selects the Secure Digital Host Controller Interface (SDHCI)
186	  often referrered to as the HSMMC block in some of the Samsung S3C
187	  range of SoC.
188
189	  If you have a controller with this interface, say Y or M here.
190
191	  If unsure, say N.
192
193config MMC_SDHCI_SIRF
194	tristate "SDHCI support on CSR SiRFprimaII and SiRFmarco SoCs"
195	depends on ARCH_SIRF
196	depends on MMC_SDHCI_PLTFM
197	help
198	  This selects the SDHCI support for SiRF System-on-Chip devices.
199
200	  If you have a controller with this interface, say Y or M here.
201
202	  If unsure, say N.
203
204config MMC_SDHCI_PXAV3
205	tristate "Marvell MMP2 SD Host Controller support (PXAV3)"
206	depends on CLKDEV_LOOKUP
207	select MMC_SDHCI
208	select MMC_SDHCI_PLTFM
209	default CPU_MMP2
210	help
211	  This selects the Marvell(R) PXAV3 SD Host Controller.
212	  If you have a MMP2 platform with SD Host Controller
213	  and a card slot, say Y or M here.
214
215	  If unsure, say N.
216
217config MMC_SDHCI_PXAV2
218	tristate "Marvell PXA9XX SD Host Controller support (PXAV2)"
219	depends on CLKDEV_LOOKUP
220	select MMC_SDHCI
221	select MMC_SDHCI_PLTFM
222	default CPU_PXA910
223	help
224	  This selects the Marvell(R) PXAV2 SD Host Controller.
225	  If you have a PXA9XX platform with SD Host Controller
226	  and a card slot, say Y or M here.
227
228	  If unsure, say N.
229
230config MMC_SDHCI_SPEAR
231	tristate "SDHCI support on ST SPEAr platform"
232	depends on MMC_SDHCI && PLAT_SPEAR
233	help
234	  This selects the Secure Digital Host Controller Interface (SDHCI)
235	  often referrered to as the HSMMC block in some of the ST SPEAR range
236	  of SoC
237
238	  If you have a controller with this interface, say Y or M here.
239
240	  If unsure, say N.
241
242config MMC_SDHCI_S3C_DMA
243	bool "DMA support on S3C SDHCI"
244	depends on MMC_SDHCI_S3C
245	help
246	  Enable DMA support on the Samsung S3C SDHCI glue. The DMA
247	  has proved to be problematic if the controller encounters
248	  certain errors, and thus should be treated with care.
249
250	  YMMV.
251
252config MMC_SDHCI_BCM_KONA
253	tristate "SDHCI support on Broadcom KONA platform"
254	depends on ARCH_BCM
255	select MMC_SDHCI_PLTFM
256	help
257	  This selects the Broadcom Kona Secure Digital Host Controller
258	  Interface(SDHCI) support.
259	  This is used in Broadcom mobile SoCs.
260
261	  If you have a controller with this interface, say Y or M here.
262
263config MMC_SDHCI_BCM2835
264	tristate "SDHCI platform support for the BCM2835 SD/MMC Controller"
265	depends on ARCH_BCM2835
266	depends on MMC_SDHCI_PLTFM
267	select MMC_SDHCI_IO_ACCESSORS
268	help
269	  This selects the BCM2835 SD/MMC controller. If you have a BCM2835
270	  platform with SD or MMC devices, say Y or M here.
271
272	  If unsure, say N.
273
274config MMC_OMAP
275	tristate "TI OMAP Multimedia Card Interface support"
276	depends on ARCH_OMAP
277	select TPS65010 if MACH_OMAP_H2
278	help
279	  This selects the TI OMAP Multimedia card Interface.
280	  If you have an OMAP board with a Multimedia Card slot,
281	  say Y or M here.
282
283	  If unsure, say N.
284
285config MMC_OMAP_HS
286	tristate "TI OMAP High Speed Multimedia Card Interface support"
287	depends on ARCH_OMAP2PLUS || COMPILE_TEST
288	help
289	  This selects the TI OMAP High Speed Multimedia card Interface.
290	  If you have an omap2plus board with a Multimedia Card slot,
291	  say Y or M here.
292
293	  If unsure, say N.
294
295config MMC_WBSD
296	tristate "Winbond W83L51xD SD/MMC Card Interface support"
297	depends on ISA_DMA_API
298	help
299	  This selects the Winbond(R) W83L51xD Secure digital and
300          Multimedia card Interface.
301	  If you have a machine with a integrated W83L518D or W83L519D
302	  SD/MMC card reader, say Y or M here.
303
304	  If unsure, say N.
305
306config MMC_AU1X
307	tristate "Alchemy AU1XX0 MMC Card Interface support"
308	depends on MIPS_ALCHEMY
309	help
310	  This selects the AMD Alchemy(R) Multimedia card interface.
311	  If you have a Alchemy platform with a MMC slot, say Y or M here.
312
313	  If unsure, say N.
314
315config MMC_ATMELMCI
316	tristate "Atmel SD/MMC Driver (Multimedia Card Interface)"
317	depends on AVR32 || ARCH_AT91
318	help
319	  This selects the Atmel Multimedia Card Interface driver. If
320	  you have an AT32 (AVR32) or AT91 platform with a Multimedia
321	  Card slot, say Y or M here.
322
323	  If unsure, say N.
324
325config MMC_MSM
326	tristate "Qualcomm SDCC Controller Support"
327	depends on MMC && ARCH_MSM
328	help
329	  This provides support for the SD/MMC cell found in the
330	  MSM and QSD SOCs from Qualcomm. The controller also has
331	  support for SDIO devices.
332
333config MMC_MXC
334	tristate "Freescale i.MX21/27/31 or MPC512x Multimedia Card support"
335	depends on ARCH_MXC || PPC_MPC512x
336	help
337	  This selects the Freescale i.MX21, i.MX27, i.MX31 or MPC512x
338	  Multimedia Card Interface. If you have an i.MX or MPC512x platform
339	  with a Multimedia Card slot, say Y or M here.
340
341	  If unsure, say N.
342
343config MMC_MXS
344	tristate "Freescale MXS Multimedia Card Interface support"
345	depends on ARCH_MXS && MXS_DMA
346	help
347	  This selects the Freescale SSP MMC controller found on MXS based
348	  platforms like mx23/28.
349
350	  If unsure, say N.
351
352config MMC_TIFM_SD
353	tristate "TI Flash Media MMC/SD Interface support"
354	depends on PCI
355	select TIFM_CORE
356	help
357	  Say Y here if you want to be able to access MMC/SD cards with
358	  the Texas Instruments(R) Flash Media card reader, found in many
359	  laptops.
360	  This option 'selects' (turns on, enables) 'TIFM_CORE', but you
361	  probably also need appropriate card reader host adapter, such as
362	  'Misc devices: TI Flash Media PCI74xx/PCI76xx host adapter support
363	  (TIFM_7XX1)'.
364
365          To compile this driver as a module, choose M here: the
366	  module will be called tifm_sd.
367
368config MMC_MVSDIO
369	tristate "Marvell MMC/SD/SDIO host driver"
370	depends on PLAT_ORION
371	---help---
372	  This selects the Marvell SDIO host driver.
373	  SDIO may currently be found on the Kirkwood 88F6281 and 88F6192
374	  SoC controllers.
375
376	  To compile this driver as a module, choose M here: the
377	  module will be called mvsdio.
378
379config MMC_DAVINCI
380        tristate "TI DAVINCI Multimedia Card Interface support"
381        depends on ARCH_DAVINCI
382        help
383          This selects the TI DAVINCI Multimedia card Interface.
384          If you have an DAVINCI board with a Multimedia Card slot,
385          say Y or M here.  If unsure, say N.
386
387config MMC_GOLDFISH
388	tristate "goldfish qemu Multimedia Card Interface support"
389	depends on GOLDFISH
390	help
391	  This selects the Goldfish Multimedia card Interface emulation
392	  found on the Goldfish Android virtual device emulation.
393
394config MMC_SPI
395	tristate "MMC/SD/SDIO over SPI"
396	depends on SPI_MASTER && !HIGHMEM && HAS_DMA
397	select CRC7
398	select CRC_ITU_T
399	help
400	  Some systems access MMC/SD/SDIO cards using a SPI controller
401	  instead of using a "native" MMC/SD/SDIO controller.  This has a
402	  disadvantage of being relatively high overhead, but a compensating
403	  advantage of working on many systems without dedicated MMC/SD/SDIO
404	  controllers.
405
406	  If unsure, or if your system has no SPI master driver, say N.
407
408config MMC_S3C
409	tristate "Samsung S3C SD/MMC Card Interface support"
410	depends on ARCH_S3C24XX
411	help
412	  This selects a driver for the MCI interface found in
413          Samsung's S3C2410, S3C2412, S3C2440, S3C2442 CPUs.
414	  If you have a board based on one of those and a MMC/SD
415	  slot, say Y or M here.
416
417	  If unsure, say N.
418
419config MMC_S3C_HW_SDIO_IRQ
420       bool "Hardware support for SDIO IRQ"
421       depends on MMC_S3C
422       help
423         Enable the hardware support for SDIO interrupts instead of using
424	 the generic polling code.
425
426choice
427	prompt "Samsung S3C SD/MMC transfer code"
428	depends on MMC_S3C
429
430config MMC_S3C_PIO
431	bool "Use PIO transfers only"
432	help
433	  Use PIO to transfer data between memory and the hardware.
434
435	  PIO is slower than DMA as it requires CPU instructions to
436	  move the data. This has been the traditional default for
437	  the S3C MCI driver.
438
439config MMC_S3C_DMA
440	bool "Use DMA transfers only"
441	help
442	  Use DMA to transfer data between memory and the hardare.
443
444	  Currently, the DMA support in this driver seems to not be
445	  working properly and needs to be debugged before this
446	  option is useful.
447
448config MMC_S3C_PIODMA
449	bool "Support for both PIO and DMA"
450	help
451	  Compile both the PIO and DMA transfer routines into the
452	  driver and let the platform select at run-time which one
453	  is best.
454
455	  See notes for the DMA option.
456
457endchoice
458
459config MMC_SDRICOH_CS
460	tristate "MMC/SD driver for Ricoh Bay1Controllers"
461	depends on PCI && PCMCIA
462	help
463	  Say Y here if your Notebook reports a Ricoh Bay1Controller PCMCIA
464	  card whenever you insert a MMC or SD card into the card slot.
465
466	  To compile this driver as a module, choose M here: the
467	  module will be called sdricoh_cs.
468
469config MMC_TMIO_CORE
470	tristate
471
472config MMC_TMIO
473	tristate "Toshiba Mobile IO Controller (TMIO) MMC/SD function support"
474	depends on MFD_TMIO || MFD_ASIC3
475	select MMC_TMIO_CORE
476	help
477	  This provides support for the SD/MMC cell found in TC6393XB,
478	  T7L66XB and also HTC ASIC3
479
480config MMC_SDHI
481	tristate "SH-Mobile SDHI SD/SDIO controller support"
482	depends on SUPERH || ARCH_SHMOBILE
483	select MMC_TMIO_CORE
484	help
485	  This provides support for the SDHI SD/SDIO controller found in
486	  SuperH and ARM SH-Mobile SoCs
487
488config MMC_CB710
489	tristate "ENE CB710 MMC/SD Interface support"
490	depends on PCI
491	select CB710_CORE
492	help
493	  This option enables support for MMC/SD part of ENE CB710/720 Flash
494	  memory card reader found in some laptops (ie. some versions of
495	  HP Compaq nx9500).
496
497	  This driver can also be built as a module. If so, the module
498	  will be called cb710-mmc.
499
500config MMC_VIA_SDMMC
501	tristate "VIA SD/MMC Card Reader Driver"
502	depends on PCI
503	help
504	  This selects the VIA SD/MMC Card Reader driver, say Y or M here.
505	  VIA provides one multi-functional card reader which integrated into
506	  some motherboards manufactured by VIA. This card reader supports
507	  SD/MMC/SDHC.
508	  If you have a controller with this interface, say Y or M here.
509
510	  If unsure, say N.
511
512config SDH_BFIN
513	tristate "Blackfin Secure Digital Host support"
514	depends on (BF54x && !BF544) || (BF51x && !BF512)
515	help
516	  If you say yes here you will get support for the Blackfin on-chip
517	  Secure Digital Host interface.  This includes support for MMC and
518	  SD cards.
519
520	  To compile this driver as a module, choose M here: the
521	  module will be called bfin_sdh.
522
523	  If unsure, say N.
524
525config SDH_BFIN_MISSING_CMD_PULLUP_WORKAROUND
526	bool "Blackfin EZkit Missing SDH_CMD Pull Up Resistor Workaround"
527	depends on SDH_BFIN
528	help
529	  If you say yes here SD-Cards may work on the EZkit.
530
531config MMC_DW
532	tristate "Synopsys DesignWare Memory Card Interface"
533	depends on ARC || ARM
534	help
535	  This selects support for the Synopsys DesignWare Mobile Storage IP
536	  block, this provides host support for SD and MMC interfaces, in both
537	  PIO and external DMA modes.
538
539config MMC_DW_IDMAC
540	bool "Internal DMAC interface"
541	depends on MMC_DW
542	help
543	  This selects support for the internal DMAC block within the Synopsys
544	  Designware Mobile Storage IP block. This disables the external DMA
545	  interface.
546
547config MMC_DW_PLTFM
548	tristate "Synopsys Designware MCI Support as platform device"
549	depends on MMC_DW
550	default y
551	help
552	  This selects the common helper functions support for Host Controller
553	  Interface based platform driver. Please select this option if the IP
554	  is present as a platform device. This is the common interface for the
555	  Synopsys Designware IP.
556
557	  If you have a controller with this interface, say Y or M here.
558
559	  If unsure, say Y.
560
561config MMC_DW_EXYNOS
562	tristate "Exynos specific extensions for Synopsys DW Memory Card Interface"
563	depends on MMC_DW
564	select MMC_DW_PLTFM
565	help
566	  This selects support for Samsung Exynos SoC specific extensions to the
567	  Synopsys DesignWare Memory Card Interface driver. Select this option
568	  for platforms based on Exynos4 and Exynos5 SoC's.
569
570config MMC_DW_SOCFPGA
571	tristate "SOCFPGA specific extensions for Synopsys DW Memory Card Interface"
572	depends on MMC_DW && MFD_SYSCON
573	select MMC_DW_PLTFM
574	help
575	  This selects support for Altera SoCFPGA specific extensions to the
576	  Synopsys DesignWare Memory Card Interface driver.
577
578config MMC_DW_PCI
579	tristate "Synopsys Designware MCI support on PCI bus"
580	depends on MMC_DW && PCI
581	help
582	  This selects the PCI bus for the Synopsys Designware Mobile Storage IP.
583	  Select this option if the IP is present on PCI platform.
584
585	  If you have a controller with this interface, say Y or M here.
586
587	  If unsure, say N.
588
589config MMC_SH_MMCIF
590	tristate "SuperH Internal MMCIF support"
591	depends on MMC_BLOCK && (SUPERH || ARCH_SHMOBILE)
592	help
593	  This selects the MMC Host Interface controller (MMCIF).
594
595	  This driver supports MMCIF in sh7724/sh7757/sh7372.
596
597config MMC_JZ4740
598	tristate "JZ4740 SD/Multimedia Card Interface support"
599	depends on MACH_JZ4740
600	help
601	  This selects support for the SD/MMC controller on Ingenic JZ4740
602	  SoCs.
603	  If you have a board based on such a SoC and with a SD/MMC slot,
604	  say Y or M here.
605
606config MMC_VUB300
607	tristate "VUB300 USB to SDIO/SD/MMC Host Controller support"
608	depends on USB
609	help
610	  This selects support for Elan Digital Systems' VUB300 chip.
611
612	  The VUB300 is a USB-SDIO Host Controller Interface chip
613	  that enables the host computer to use SDIO/SD/MMC cards
614	  via a USB 2.0 or USB 1.1 host.
615
616	  The VUB300 chip will be found in both physically separate
617	  USB to SDIO/SD/MMC adapters and embedded on some motherboards.
618
619	  The VUB300 chip supports SD and MMC memory cards in addition
620	  to single and multifunction SDIO cards.
621
622	  Some SDIO cards will need a firmware file to be loaded and
623	  sent to VUB300 chip in order to achieve better data throughput.
624	  Download these "Offload Pseudocode" from Elan Digital Systems'
625	  web-site http://www.elandigitalsystems.com/support/downloads.php
626	  and put them in /lib/firmware. Note that without these additional
627	  firmware files the VUB300 chip will still function, but not at
628	  the best obtainable data rate.
629
630	  To compile this mmc host controller driver as a module,
631	  choose M here: the module will be called vub300.
632
633	  If you have a computer with an embedded VUB300 chip
634	  or if you intend connecting a USB adapter based on a
635	  VUB300 chip say Y or M here.
636
637config MMC_USHC
638	tristate "USB SD Host Controller (USHC) support"
639	depends on USB
640	help
641	  This selects support for USB SD Host Controllers based on
642	  the Cypress Astoria chip with firmware compliant with CSR's
643	  USB SD Host Controller specification (CS-118793-SP).
644
645	  CSR boards with this device include: USB<>SDIO (M1985v2),
646	  and Ultrasira.
647
648	  Note: These controllers only support SDIO cards and do not
649	  support MMC or SD memory cards.
650
651config MMC_WMT
652	tristate "Wondermedia SD/MMC Host Controller support"
653	depends on ARCH_VT8500
654	default y
655	help
656	  This selects support for the SD/MMC Host Controller on
657	  Wondermedia WM8505/WM8650 based SoCs.
658
659	  To compile this driver as a module, choose M here: the
660	  module will be called wmt-sdmmc.
661
662config MMC_REALTEK_PCI
663	tristate "Realtek PCI-E SD/MMC Card Interface Driver"
664	depends on MFD_RTSX_PCI
665	help
666	  Say Y here to include driver code to support SD/MMC card interface
667	  of Realtek PCI-E card reader
668