stm32f1: Basic implementation of spi_acquire(), spi_release()
stm32f1: Basic implementation of spi_acquire(), spi_release()

Signed-off-by: Joakim Gebart <d097f2c6c8fee73e3ea75e1d62412e3886346faa@eistec.se>

zhuoshuguo/RIOT,rajma996/RIOT,arvindpdmn/RIOT,khhhh/RIOT,kaleb-himes/RIOT,tdautc19841202/RIOT,abp719/RIOT,benoit-canet/RIOT,TobiasFredersdorf/RIOT,latsku/RIOT,alignan/RIOT,x3ro/RIOT,gbarnett/RIOT,Ell-i/RIOT,sumanpanchal/RIOT,roberthartung/RIOT,Lexandro92/RIOT-CoAP,hamilton-mote/RIOT-OS,arvindpdmn/RIOT,lebrush/RIOT,FrancescoErmini/RIOT,rfuentess/RIOT,robixnai/RIOT,Yonezawa-T2/RIOT,katezilla/RIOT,Yonezawa-T2/RIOT,mfrey/RIOT,centurysys/RIOT,jremmert-phytec-iot/RIOT,RBartz/RIOT,jbeyerstedt/RIOT-OTA-update,rajma996/RIOT,Josar/RIOT,plushvoxel/RIOT,alex1818/RIOT,thiagohd/RIOT,herrfz/RIOT,adjih/RIOT,jremmert-phytec-iot/RIOT,gautric/RIOT,jasonatran/RIOT,dkm/RIOT,alignan/RIOT,jhollister/RIOT,koenning/RIOT,yogo1212/RIOT,jbeyerstedt/RIOT-OTA-update,FrancescoErmini/RIOT,rakendrathapa/RIOT,adrianghc/RIOT,ant9000/RIOT,Hyungsin/RIOT-OS,josephnoir/RIOT,backenklee/RIOT,chris-wood/RIOT,abp719/RIOT,openkosmosorg/RIOT,ximus/RIOT,ntrtrung/RIOT,herrfz/RIOT-old,yogo1212/RIOT,JensErdmann/RIOT,zhuoshuguo/RIOT,miri64/RIOT,DipSwitch/RIOT,immesys/RiSyn,neiljay/RIOT,rousselk/RIOT,brettswann/RIOT,jfischer-phytec-iot/RIOT,ntrtrung/RIOT,neumodisch/RIOT,BytesGalore/RIOT,d00616/RIOT,biboc/RIOT,tdautc19841202/RIOT,malosek/RIOT,marcosalm/RIOT,Josar/RIOT,tfar/RIOT,toonst/RIOT,Josar/RIOT,Osblouf/RIOT,benoit-canet/RIOT,backenklee/RIOT,malosek/RIOT,khhhh/RIOT,ThanhVic/RIOT,kerneltask/RIOT,lebrush/RIOT,Darredevil/RIOT,OlegHahm/RIOT,jferreir/RIOT,dailab/RIOT,kbumsik/RIOT,zhuoshuguo/RIOT,syin2/RIOT,Osblouf/RIOT,mfrey/RIOT,Yonezawa-T2/RIOT,herrfz/RIOT,ThanhVic/RIOT,jasonatran/RIOT,RIOT-OS/RIOT,avmelnikoff/RIOT,ant9000/RIOT,l3nko/RIOT,RBartz/RIOT,ximus/RIOT,Hyungsin/RIOT-OS,lebrush/RIOT,robixnai/RIOT,MonsterCode8000/RIOT,alex1818/RIOT,plushvoxel/RIOT,rousselk/RIOT,DipSwitch/RIOT,LudwigKnuepfer/RIOT,rfswarm2/RIOT,adjih/RIOT,daniel-k/RIOT,dhruvvyas90/RIOT,OTAkeys/RIOT,watr-li/RIOT,stevenj/RIOT,jfischer-phytec-iot/RIOT,latsku/RIOT,katezilla/RIOT,herrfz/RIOT,x3ro/RIOT,JensErdmann/RIOT,JensErdmann/RIOT,kaleb-himes/RIOT,tfar/RIOT,kaspar030/RIOT,gebart/RIOT,phiros/RIOT,smlng/RIOT,chris-wood/RIOT,binarylemon/RIOT,EmuxEvans/RIOT,altairpearl/RIOT,cladmi/RIOT,gbarnett/RIOT,Darredevil/RIOT,RIOT-OS/RIOT,tfar/RIOT,ThanhVic/RIOT,jasonatran/RIOT,mziegert/RIOT,haoyangyu/RIOT,d00616/RIOT,herrfz/RIOT-old,msolters/RIOT,Darredevil/RIOT,jasonatran/RIOT,LudwigKnuepfer/RIOT,stevenj/RIOT,rfuentess/RIOT,msolters/RIOT,chris-wood/RIOT,toonst/RIOT,rfuentess/RIOT,gautric/RIOT,wentaoshang/RIOT,DipSwitch/RIOT,josephnoir/RIOT,FrancescoErmini/RIOT,gbarnett/RIOT,dhruvvyas90/RIOT,latsku/RIOT,ks156/RIOT,attdona/RIOT,aeneby/RIOT,koenning/RIOT,mtausig/RIOT,MohmadAyman/RIOT,abkam07/RIOT,kaspar030/RIOT,arvindpdmn/RIOT,neiljay/RIOT,BytesGalore/RIOT,ks156/RIOT,Lexandro92/RIOT-CoAP,immesys/RiSyn,yogo1212/RIOT,neiljay/RIOT,wentaoshang/RIOT,MarkXYang/RIOT,malosek/RIOT,MarkXYang/RIOT,changbiao/RIOT,ntrtrung/RIOT,jremmert-phytec-iot/RIOT,roberthartung/RIOT,asanka-code/RIOT,basilfx/RIOT,ximus/RIOT,foss-for-synopsys-dwc-arc-processors/RIOT,thiagohd/RIOT,Ell-i/RIOT,LudwigOrtmann/RIOT,DipSwitch/RIOT,herrfz/RIOT-old,A-Paul/RIOT,d00616/RIOT,dkm/RIOT,jfischer-phytec-iot/RIOT,koenning/RIOT,rousselk/RIOT,abp719/RIOT,TobiasFredersdorf/RIOT,biboc/RIOT,authmillenon/RIOT,aeneby/RIOT,MonsterCode8000/RIOT,OTAkeys/RIOT,jhollister/RIOT,adrianghc/RIOT,avmelnikoff/RIOT,sgso/RIOT,attdona/RIOT,bartfaizoltan/RIOT,FrancescoErmini/RIOT,Hyungsin/RIOT-OS,Josar/RIOT,foss-for-synopsys-dwc-arc-processors/RIOT,BytesGalore/RIOT,thomaseichinger/RIOT,shady33/RIOT,MarkXYang/RIOT,adrianghc/RIOT,fnack/RIOT,adjih/RIOT,MohmadAyman/RIOT,tdautc19841202/RIOT,neumodisch/RIOT,malosek/RIOT,sgso/RIOT,asanka-code/RIOT,shady33/RIOT,aeneby/RIOT,kushalsingh007/RIOT,khhhh/RIOT,patkan/RIOT,RubikonAlpha/RIOT,asanka-code/RIOT,rfswarm2/RIOT,TobiasFredersdorf/RIOT,herrfz/RIOT-old,dailab/RIOT,kb2ma/RIOT,OlegHahm/RIOT,rfswarm/RIOT,malosek/RIOT,fnack/RIOT,kbumsik/RIOT,mtausig/RIOT,foss-for-synopsys-dwc-arc-processors/RIOT,lazytech-org/RIOT,khhhh/RIOT,lebrush/RIOT,sgso/RIOT,openkosmosorg/RIOT,kerneltask/RIOT,ks156/RIOT,MarkXYang/RIOT,luciotorre/RIOT,EmuxEvans/RIOT,jferreir/RIOT,yogo1212/RIOT,rfswarm/RIOT,RIOT-OS/RIOT,jhollister/RIOT,koenning/RIOT,MonsterCode8000/RIOT,chris-wood/RIOT,robixnai/RIOT,abkam07/RIOT,lebrush/RIOT,kaleb-himes/RIOT,bartfaizoltan/RIOT,l3nko/RIOT,marcosalm/RIOT,alex1818/RIOT,kushalsingh007/RIOT,abp719/RIOT,beurdouche/RIOT,biboc/RIOT,A-Paul/RIOT,phiros/RIOT,miri64/RIOT,shady33/RIOT,sgso/RIOT,gautric/RIOT,rakendrathapa/RIOT,centurysys/RIOT,automote/RIOT,phiros/RIOT,wentaoshang/RIOT,PSHIVANI/Riot-Code,hamilton-mote/RIOT-OS,abkam07/RIOT,altairpearl/RIOT,luciotorre/RIOT,syin2/RIOT,PSHIVANI/Riot-Code,dailab/RIOT,plushvoxel/RIOT,LudwigOrtmann/RIOT,kbumsik/RIOT,thiagohd/RIOT,jremmert-phytec-iot/RIOT,thiagohd/RIOT,mtausig/RIOT,brettswann/RIOT,authmillenon/RIOT,RubikonAlpha/RIOT,backenklee/RIOT,rfswarm2/RIOT,kaspar030/RIOT,jferreir/RIOT,PSHIVANI/Riot-Code,kaleb-himes/RIOT,neiljay/RIOT,rajma996/RIOT,gautric/RIOT,A-Paul/RIOT,mziegert/RIOT,jremmert-phytec-iot/RIOT,patkan/RIOT,asanka-code/RIOT,malosek/RIOT,abkam07/RIOT,cladmi/RIOT,JensErdmann/RIOT,ximus/RIOT,arvindpdmn/RIOT,msolters/RIOT,brettswann/RIOT,smlng/RIOT,Osblouf/RIOT,wentaoshang/RIOT,latsku/RIOT,jremmert-phytec-iot/RIOT,haoyangyu/RIOT,kaspar030/RIOT,d00616/RIOT,zhuoshuguo/RIOT,RIOT-OS/RIOT,robixnai/RIOT,yogo1212/RIOT,EmuxEvans/RIOT,tdautc19841202/RIOT,miri64/RIOT,altairpearl/RIOT,DipSwitch/RIOT,RubikonAlpha/RIOT,binarylemon/RIOT,katezilla/RIOT,kYc0o/RIOT,brettswann/RIOT,daniel-k/RIOT,Yonezawa-T2/RIOT,rajma996/RIOT,backenklee/RIOT,ThanhVic/RIOT,cladmi/RIOT,marcosalm/RIOT,basilfx/RIOT,rfuentess/RIOT,thiagohd/RIOT,x3ro/RIOT,kerneltask/RIOT,dkm/RIOT,JensErdmann/RIOT,adrianghc/RIOT,sumanpanchal/RIOT,kbumsik/RIOT,koenning/RIOT,changbiao/RIOT,herrfz/RIOT,jhollister/RIOT,EmuxEvans/RIOT,luciotorre/RIOT,patkan/RIOT,dhruvvyas90/RIOT,Lexandro92/RIOT-CoAP,rousselk/RIOT,BytesGalore/RIOT,robixnai/RIOT,gautric/RIOT,MonsterCode8000/RIOT,katezilla/RIOT,arvindpdmn/RIOT,LudwigOrtmann/RIOT,msolters/RIOT,TobiasFredersdorf/RIOT,josephnoir/RIOT,brettswann/RIOT,ntrtrung/RIOT,avmelnikoff/RIOT,latsku/RIOT,tfar/RIOT,centurysys/RIOT,TobiasFredersdorf/RIOT,ximus/RIOT,kushalsingh007/RIOT,marcosalm/RIOT,katezilla/RIOT,shady33/RIOT,wentaoshang/RIOT,kushalsingh007/RIOT,RubikonAlpha/RIOT,ant9000/RIOT,rousselk/RIOT,rajma996/RIOT,changbiao/RIOT,smlng/RIOT,OTAkeys/RIOT,fnack/RIOT,dkm/RIOT,watr-li/RIOT,l3nko/RIOT,authmillenon/RIOT,LudwigKnuepfer/RIOT,cladmi/RIOT,LudwigOrtmann/RIOT,thomaseichinger/RIOT,adjih/RIOT,mziegert/RIOT,stevenj/RIOT,RubikonAlpha/RIOT,toonst/RIOT,rakendrathapa/RIOT,lebrush/RIOT,bartfaizoltan/RIOT,OTAkeys/RIOT,mfrey/RIOT,changbiao/RIOT,authmillenon/RIOT,patkan/RIOT,Josar/RIOT,plushvoxel/RIOT,kerneltask/RIOT,gebart/RIOT,kaspar030/RIOT,robixnai/RIOT,zhuoshuguo/RIOT,MonsterCode8000/RIOT,fnack/RIOT,kerneltask/RIOT,PSHIVANI/Riot-Code,patkan/RIOT,beurdouche/RIOT,DipSwitch/RIOT,shady33/RIOT,haoyangyu/RIOT,mziegert/RIOT,foss-for-synopsys-dwc-arc-processors/RIOT,l3nko/RIOT,MohmadAyman/RIOT,asanka-code/RIOT,Hyungsin/RIOT-OS,Hyungsin/RIOT-OS,patkan/RIOT,bartfaizoltan/RIOT,asanka-code/RIOT,avmelnikoff/RIOT,attdona/RIOT,dailab/RIOT,x3ro/RIOT,LudwigKnuepfer/RIOT,benoit-canet/RIOT,binarylemon/RIOT,jferreir/RIOT,immesys/RiSyn,mtausig/RIOT,jhollister/RIOT,josephnoir/RIOT,alex1818/RIOT,tdautc19841202/RIOT,roberthartung/RIOT,mfrey/RIOT,authmillenon/RIOT,openkosmosorg/RIOT,Osblouf/RIOT,OlegHahm/RIOT,brettswann/RIOT,automote/RIOT,sgso/RIOT,rfswarm2/RIOT,RBartz/RIOT,herrfz/RIOT,rajma996/RIOT,attdona/RIOT,MarkXYang/RIOT,dailab/RIOT,luciotorre/RIOT,FrancescoErmini/RIOT,haoyangyu/RIOT,alex1818/RIOT,RubikonAlpha/RIOT,aeneby/RIOT,Osblouf/RIOT,watr-li/RIOT,abkam07/RIOT,Osblouf/RIOT,arvindpdmn/RIOT,mziegert/RIOT,jferreir/RIOT,dhruvvyas90/RIOT,immesys/RiSyn,herrfz/RIOT,kb2ma/RIOT,A-Paul/RIOT,stevenj/RIOT,phiros/RIOT,Lexandro92/RIOT-CoAP,rousselk/RIOT,marcosalm/RIOT,immesys/RiSyn,openkosmosorg/RIOT,kYc0o/RIOT,MohmadAyman/RIOT,mfrey/RIOT,ks156/RIOT,thomaseichinger/RIOT,binarylemon/RIOT,rfswarm2/RIOT,RBartz/RIOT,beurdouche/RIOT,sumanpanchal/RIOT,ThanhVic/RIOT,altairpearl/RIOT,altairpearl/RIOT,beurdouche/RIOT,centurysys/RIOT,openkosmosorg/RIOT,automote/RIOT,abp719/RIOT,jfischer-phytec-iot/RIOT,gebart/RIOT,gbarnett/RIOT,dhruvvyas90/RIOT,adrianghc/RIOT,gebart/RIOT,toonst/RIOT,binarylemon/RIOT,koenning/RIOT,gbarnett/RIOT,Ell-i/RIOT,basilfx/RIOT,Darredevil/RIOT,syin2/RIOT,PSHIVANI/Riot-Code,EmuxEvans/RIOT,centurysys/RIOT,kb2ma/RIOT,luciotorre/RIOT,smlng/RIOT,mtausig/RIOT,jbeyerstedt/RIOT-OTA-update,ntrtrung/RIOT,LudwigKnuepfer/RIOT,rfswarm2/RIOT,kushalsingh007/RIOT,ntrtrung/RIOT,herrfz/RIOT-old,toonst/RIOT,changbiao/RIOT,biboc/RIOT,thomaseichinger/RIOT,automote/RIOT,x3ro/RIOT,rfswarm/RIOT,lazytech-org/RIOT,kYc0o/RIOT,stevenj/RIOT,shady33/RIOT,miri64/RIOT,watr-li/RIOT,marcosalm/RIOT,lazytech-org/RIOT,wentaoshang/RIOT,attdona/RIOT,msolters/RIOT,tfar/RIOT,haoyangyu/RIOT,ThanhVic/RIOT,changbiao/RIOT,EmuxEvans/RIOT,mziegert/RIOT,roberthartung/RIOT,phiros/RIOT,MarkXYang/RIOT,bartfaizoltan/RIOT,hamilton-mote/RIOT-OS,roberthartung/RIOT,automote/RIOT,zhuoshuguo/RIOT,benoit-canet/RIOT,avmelnikoff/RIOT,rfswarm/RIOT,adjih/RIOT,kushalsingh007/RIOT,rfswarm/RIOT,abp719/RIOT,JensErdmann/RIOT,ant9000/RIOT,Lexandro92/RIOT-CoAP,openkosmosorg/RIOT,foss-for-synopsys-dwc-arc-processors/RIOT,RBartz/RIOT,neumodisch/RIOT,bartfaizoltan/RIOT,LudwigOrtmann/RIOT,binarylemon/RIOT,gebart/RIOT,gbarnett/RIOT,tdautc19841202/RIOT,neumodisch/RIOT,kYc0o/RIOT,jbeyerstedt/RIOT-OTA-update,chris-wood/RIOT,ant9000/RIOT,MohmadAyman/RIOT,smlng/RIOT,OTAkeys/RIOT,RIOT-OS/RIOT,thiagohd/RIOT,benoit-canet/RIOT,fnack/RIOT,plushvoxel/RIOT,latsku/RIOT,OlegHahm/RIOT,PSHIVANI/Riot-Code,fnack/RIOT,biboc/RIOT,khhhh/RIOT,l3nko/RIOT,dhruvvyas90/RIOT,abkam07/RIOT,daniel-k/RIOT,RBartz/RIOT,OlegHahm/RIOT,hamilton-mote/RIOT-OS,stevenj/RIOT,dkm/RIOT,watr-li/RIOT,jfischer-phytec-iot/RIOT,l3nko/RIOT,thomaseichinger/RIOT,backenklee/RIOT,msolters/RIOT,aeneby/RIOT,watr-li/RIOT,MohmadAyman/RIOT,Ell-i/RIOT,kaleb-himes/RIOT,immesys/RiSyn,lazytech-org/RIOT,jasonatran/RIOT,BytesGalore/RIOT,Darredevil/RIOT,alignan/RIOT,alignan/RIOT,kYc0o/RIOT,ximus/RIOT,jferreir/RIOT,MonsterCode8000/RIOT,sumanpanchal/RIOT,rfuentess/RIOT,alex1818/RIOT,miri64/RIOT,daniel-k/RIOT,LudwigOrtmann/RIOT,A-Paul/RIOT,phiros/RIOT,syin2/RIOT,daniel-k/RIOT,Darredevil/RIOT,ks156/RIOT,rfswarm/RIOT,basilfx/RIOT,beurdouche/RIOT,khhhh/RIOT,Yonezawa-T2/RIOT,automote/RIOT,authmillenon/RIOT,jbeyerstedt/RIOT-OTA-update,haoyangyu/RIOT,benoit-canet/RIOT,d00616/RIOT,syin2/RIOT,luciotorre/RIOT,hamilton-mote/RIOT-OS,rakendrathapa/RIOT,chris-wood/RIOT,josephnoir/RIOT,Ell-i/RIOT,d00616/RIOT,attdona/RIOT,sumanpanchal/RIOT,neiljay/RIOT,basilfx/RIOT,kb2ma/RIOT,daniel-k/RIOT,neumodisch/RIOT,FrancescoErmini/RIOT,kbumsik/RIOT,cladmi/RIOT,sumanpanchal/RIOT,rakendrathapa/RIOT,yogo1212/RIOT,neumodisch/RIOT,altairpearl/RIOT,kb2ma/RIOT,lazytech-org/RIOT,Lexandro92/RIOT-CoAP,rakendrathapa/RIOT,jhollister/RIOT,centurysys/RIOT,sgso/RIOT,Yonezawa-T2/RIOT,alignan/RIOT