On Fri, Dec 11, 2009 at 20:16 +0900, Mark Brown wrote: > On Fri, Dec 11, 2009 at 12:00:11PM +0100, Marc Zyngier wrote: > > Kukjin Kim <kgene.kim@xxxxxxxxxxx> wrote: Hi Mark Brown and Marc Zyngier, > > > +/* define the number of gpios we need to the one after the GPR() range */ > > > +#define ARCH_NR_GPIOS (S5P6440_GPR(S5P6440_GPIO_R_NR) > + 1) > > > Doing so prevents the use of GPIO expanders. Either provide a config > > option to provide additional GPIO space, or just get rid of the #define. To satisfy your request, I know what to do. However, I don't know well the reason. Please explain the reason why need the use of GPIO expanders. As you know, the number of hardware GPIO pin is fixed and limited. And the limit value is ARCH_NR_GPIOS. > It also prevents the use of external devices with interrupt controllers > (eg, most PMICs these days). See the S3C24xx and S3C64xx code for > examples of how to avoid this limit. As you mentioned, I can find the code in the S3C24XX, but I can't in the S3C64XX. The S3C64XX codes are as follows: /* from arch/arm/mach-s3c6400/include/mach/gpio.h */ 93 /* define the number of gpios we need to the one after the GPQ() range */ 94 #define ARCH_NR_GPIOS (S3C64XX_GPQ(S3C64XX_GPIO_Q_NR) + 1) Anyway, if the definition like my patch becomes problem, please let me know the reason. Thanks. Best regards, Kgene. -- Kukjin Kim <kgene.kim@xxxxxxxxxxx>, Senior Engineer, System LSI Division, SAMSUNG ELECTRONICS CO., LTD. -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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