From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexandre Belloni Subject: Re: [PATCH v5 5/9] rtc: at91sam9: make use of syscon/regmap to access GPBR registers Date: Thu, 11 Sep 2014 19:42:09 +0200 Message-ID: <20140911174209.GE3131@piout.net> References: <1410441525-25258-6-git-send-email-boris.brezillon@free-electrons.com> <1410443588-9092-1-git-send-email-boris.brezillon@free-electrons.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1410443588-9092-1-git-send-email-boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Boris BREZILLON Cc: Nicolas Ferre , Jean-Christophe Plagniol-Villard , Andrew Victor , Alessandro Zummo , rtc-linux-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org, Johan Hovold , Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: devicetree@vger.kernel.org On 11/09/2014 at 15:53:08 +0200, Boris Brezillon wrote : > The GPBR registers are not part of the RTT block and thus should not be > defined in the reg property of the rtt node. > > Use syscon to provide a proper DT representation and reference the GPBR > syscon device in a new "atmel,time-reg" property which store both the > syscon device phandle and the register offset within the GPBR block. > > When using non DT boards, we won't be able to retrieve the syscon regmap, > hence we need to create our own regmap using the memory region defined > in the 2nd memory resource assigned to the RTT platform device. > > Signed-off-by: Boris BREZILLON > --- > drivers/rtc/Kconfig | 1 + > drivers/rtc/rtc-at91sam9.c | 59 +++++++++++++++++++++++++++++++++++++++------- > 2 files changed, 51 insertions(+), 9 deletions(-) > > diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig > index a168e96..7d76da8 100644 > --- a/drivers/rtc/Kconfig > +++ b/drivers/rtc/Kconfig > @@ -1081,6 +1081,7 @@ config RTC_DRV_AT91RM9200 > config RTC_DRV_AT91SAM9 > tristate "AT91SAM9x/AT91CAP9 RTT as RTC" > depends on ARCH_AT91 && !(ARCH_AT91RM9200 || ARCH_AT91X40) > + select MFD_SYSCON > help > RTC driver for the Atmel AT91SAM9x and AT91CAP9 internal RTT > (Real Time Timer). These timers are powered by the backup power > diff --git a/drivers/rtc/rtc-at91sam9.c b/drivers/rtc/rtc-at91sam9.c > index d72c34d..944e317 100644 > --- a/drivers/rtc/rtc-at91sam9.c > +++ b/drivers/rtc/rtc-at91sam9.c > @@ -21,6 +21,8 @@ > #include > #include > #include > +#include > +#include > > /* > * This driver uses two configurable hardware resources that live in the > @@ -72,7 +74,8 @@ struct sam9_rtc { > void __iomem *rtt; > struct rtc_device *rtcdev; > u32 imr; > - void __iomem *gpbr; > + struct regmap *gpbr; > + unsigned int gpbr_offset; > int irq; > }; > > @@ -81,10 +84,19 @@ struct sam9_rtc { > #define rtt_writel(rtc, field, val) \ > writel((val), (rtc)->rtt + AT91_RTT_ ## field) > > -#define gpbr_readl(rtc) \ > - readl((rtc)->gpbr) > -#define gpbr_writel(rtc, val) \ > - writel((val), (rtc)->gpbr) > +static inline unsigned int gpbr_readl(struct sam9_rtc *rtc) > +{ > + unsigned int val; > + > + regmap_read(rtc->gpbr, rtc->gpbr_offset, &val); > + > + return val; > +} > + > +static inline void gpbr_writel(struct sam9_rtc *rtc, unsigned int val) > +{ > + regmap_write(rtc->gpbr, rtc->gpbr_offset, val); > +} > > /* > * Read current time and date in RTC > @@ -301,6 +313,12 @@ static const struct rtc_class_ops at91_rtc_ops = { > .alarm_irq_enable = at91_rtc_alarm_irq_enable, > }; > > +static struct regmap_config gpbr_regmap_config = { > + .reg_bits = 32, > + .val_bits = 32, > + .reg_stride = 4, > +}; > + > /* > * Initialize and install RTC driver > */ > @@ -334,10 +352,33 @@ static int at91_rtc_probe(struct platform_device *pdev) > if (IS_ERR(rtc->rtt)) > return PTR_ERR(rtc->rtt); > > - r = platform_get_resource(pdev, IORESOURCE_MEM, 1); > - rtc->gpbr = devm_ioremap_resource(&pdev->dev, r); > - if (IS_ERR(rtc->gpbr)) > - return PTR_ERR(rtc->rtt); > + if (!pdev->dev.of_node) { > + void __iomem *gpbr; > + > + r = platform_get_resource(pdev, IORESOURCE_MEM, 1); > + gpbr = devm_ioremap_resource(&pdev->dev, r); > + if (IS_ERR(gpbr)) > + return PTR_ERR(gpbr); > + Maybe you could add a comment here as this is soon to be dead code. > + rtc->gpbr = regmap_init_mmio(NULL, gpbr, > + &gpbr_regmap_config); > + } else { > + struct of_phandle_args args; > + > + ret = of_parse_phandle_with_fixed_args(pdev->dev.of_node, > + "atmel,rtt-rtc-time-reg", 1, 0, > + &args); > + if (ret) > + return ret; > + > + rtc->gpbr = syscon_node_to_regmap(args.np); > + rtc->gpbr_offset = args.args[0]; > + } > + > + if (IS_ERR(rtc->gpbr)) { > + dev_err(&pdev->dev, "failed to retrieve gpbr regmap, aborting.\n"); > + return -ENOMEM; > + } > > mr = rtt_readl(rtc, MR); > > -- > 1.9.1 > -- Alexandre Belloni, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html