From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pankaj Dubey Subject: Re: [PATCH 06/10] ARM: EXYNOS: Add support for mapping PMU base address via DT Date: Sat, 05 Apr 2014 19:53:53 +0900 Message-ID: <533FE0C1.6070207@samsung.com> References: <1396425058-4012-1-git-send-email-pankaj.dubey@samsung.com> <1396425058-4012-7-git-send-email-pankaj.dubey@samsung.com> <533BF905.6070701@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-reply-to: <533BF905.6070701@samsung.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Sylwester Nawrocki Cc: kgene.kim@samsung.com, linux@arm.linux.org.uk, linux-kernel@vger.kernel.org, linux-samsung-soc@vger.kernel.org, Young-Gun Jang , chow.kim@samsung.com, linux-arm-kernel@lists.infradead.org List-Id: linux-samsung-soc@vger.kernel.org On 04/02/2014 08:48 PM, Sylwester Nawrocki wrote: > On 02/04/14 09:50, Pankaj Dubey wrote: >> From: Young-Gun Jang >> >> Add support for mapping Exynos Power Management Unit (PMU) base address >> from device tree. Code will use existing samsung pmu binding information. >> This patch also adds "get_exynos_pmubase" a helper function to return mapped base >> address to various other files under "mach-exynos". >> >> Signed-off-by: Young-Gun Jang >> Signed-off-by: Pankaj Dubey >> --- >> arch/arm/mach-exynos/common.h | 2 ++ >> arch/arm/mach-exynos/exynos.c | 44 +++++++++++++++++++++++++++++++++++++++++ >> 2 files changed, 46 insertions(+) >> > [...] >> #endif /* __ARCH_ARM_MACH_EXYNOS_COMMON_H */ >> diff --git a/arch/arm/mach-exynos/exynos.c b/arch/arm/mach-exynos/exynos.c >> index a5e1349..a5127fb 100644 >> --- a/arch/arm/mach-exynos/exynos.c >> +++ b/arch/arm/mach-exynos/exynos.c >> @@ -35,6 +35,8 @@ >> #define L2_AUX_VAL 0x7C470001 >> #define L2_AUX_MASK 0xC200ffff >> >> +static void __iomem *exynos_pmu_base __initdata; >> + >> static struct map_desc exynos4_iodesc[] __initdata = { >> { >> .virtual = (unsigned long)S3C_VA_SYS, >> @@ -245,6 +247,47 @@ void __init exynos_init_late(void) >> exynos_pm_init(); >> } >> >> +static char const *exynos_dt_pmu_match[] __initconst = { >> + "samsung,exynos4210-pmu", >> + "samsung,exynos4212-pmu", >> + "samsung,exynos4412-pmu", >> + "samsung,exynos5250-pmu", >> + NULL >> +}; >> + >> +static int __init exynos_fdt_map_pmu(unsigned long node, >> + const char *uname, int depth, void *data) >> +{ >> + struct map_desc iodesc; >> + __be32 *reg; >> + unsigned long len; >> + >> + if (of_flat_dt_match(node, exynos_dt_pmu_match)) { >> + phys_addr_t phys_addr; >> + reg = of_get_flat_dt_prop(node, "reg", &len); >> + if (reg == NULL || len != (sizeof(unsigned long) * 2)) >> + return 0; >> + >> + phys_addr = be32_to_cpu(reg[0]); >> + iodesc.pfn = __phys_to_pfn(phys_addr); >> + iodesc.length = be32_to_cpu(reg[1]) - 1; >> + iodesc.virtual = (unsigned long)S5P_VA_PMU; >> + iodesc.type = MT_DEVICE; >> + iotable_init(&iodesc, 1); > Are you sure...you need this in addition to ioremap() below ? > Can't you just use the Linux syscon API ? > There were some patches posted for syscon to make it available in earlier > system initialization stage: https://lkml.org/lkml/2014/2/19/218 Thanks for review and suggestion. We need ioremap() in addition to iotable_init to get virtual address, which will be used by other files also for read/write PMU registers. Regarding syscon early initialization, since I was not aware of any such patch earlier I have not used it. But after you suggested I tried it and modified this implementation to use syscon API and regmap API and it's working fine. I will wait for review of other patches in this series and status of above mentioned syscon API based on that I will update this in next revision. >> + exynos_pmu_base = ioremap(phys_addr, be32_to_cpu(reg[1])); >> + if (WARN_ON(!exynos_pmu_base)) >> + return -EFAULT; >> + } >> + >> + return 0; >> +} > -- > Thanks, > Sylwester > -- Best Regards, Pankaj Dubey