Re: [PATCH v2 06/10] ARM: EXYNOS: Add support for mapping PMU base address via DT
From: Tomasz Figa
Date: Fri Apr 25 2014 - 17:43:54 EST
Hi,
On 25.04.2014 14:32, Pankaj Dubey wrote:
From: Young-Gun Jang <yg1004.jang@xxxxxxxxxxx>
Add support for mapping Samsung Power Management Unit (PMU) base address
from device tree. Code will use existing samsung pmu binding information.
This patch also adds two helper functions as "get_exynos_pmuregmap" and
"get_exynos_pmuaddr".
"get_exynos_pmuregmap" returns a regmap based PMU register handle where as
"get_exynos_pmuaddr" returns ioremap virtual address.
Signed-off-by: Young-Gun Jang <yg1004.jang@xxxxxxxxxxx>
Signed-off-by: Pankaj Dubey <pankaj.dubey@xxxxxxxxxxx>
---
arch/arm/mach-exynos/Kconfig | 2 ++
arch/arm/mach-exynos/common.h | 3 ++
arch/arm/mach-exynos/exynos.c | 78 +++++++++++++++++++++++++++++++++++++++++
3 files changed, 83 insertions(+)
diff --git a/arch/arm/mach-exynos/Kconfig b/arch/arm/mach-exynos/Kconfig
index fc8bf18..2f60c90 100644
--- a/arch/arm/mach-exynos/Kconfig
+++ b/arch/arm/mach-exynos/Kconfig
@@ -26,6 +26,7 @@ config ARCH_EXYNOS4
select PINCTRL
select PM_GENERIC_DOMAINS if PM_RUNTIME
select S5P_DEV_MFC
+ select MFD_SYSCON
help
Samsung EXYNOS4 SoCs based systems
@@ -36,6 +37,7 @@ config ARCH_EXYNOS5
select HAVE_ARM_SCU if SMP
select HAVE_SMP
select PINCTRL
+ select MFD_SYSCON
help
Samsung EXYNOS5 (Cortex-A15) SoC based systems
diff --git a/arch/arm/mach-exynos/common.h b/arch/arm/mach-exynos/common.h
index 31c5964..ecfd0fc 100644
--- a/arch/arm/mach-exynos/common.h
+++ b/arch/arm/mach-exynos/common.h
@@ -57,4 +57,7 @@ struct exynos_pmu_conf {
extern void exynos_sys_powerdown_conf(enum sys_powerdown mode);
+extern struct regmap *get_exynos_pmuregmap(void);
+extern void __iomem *get_exynos_pmuaddr(void);
Do you really need these functions? Couldn't all the drivers using PMU
simply call syscon_regmap_lookup_by_phandle() or of_iomap() directly?
+
#endif /* __ARCH_ARM_MACH_EXYNOS_COMMON_H */
diff --git a/arch/arm/mach-exynos/exynos.c b/arch/arm/mach-exynos/exynos.c
index d6f405f..68f60e1 100644
--- a/arch/arm/mach-exynos/exynos.c
+++ b/arch/arm/mach-exynos/exynos.c
@@ -19,6 +19,7 @@
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/pm_domain.h>
+#include <linux/mfd/syscon.h>
#include <asm/cacheflush.h>
#include <asm/hardware/cache-l2x0.h>
@@ -36,6 +37,9 @@
#define L2_AUX_VAL 0x7C470001
#define L2_AUX_MASK 0xC200ffff
+static struct regmap *exynos_pmu_regmap;
+static void __iomem *exynos_pmu_base;
+
static struct map_desc exynos4_iodesc[] __initdata = {
{
.virtual = (unsigned long)S3C_VA_SYS,
@@ -269,6 +273,46 @@ static int __init exynos_fdt_map_chipid(unsigned long node, const char *uname,
return 1;
}
+static const struct of_device_id exynos_dt_pmu_match[] = {
+ { .compatible = "samsung,exynos4210-pmu" },
+ { .compatible = "samsung,exynos4212-pmu" },
+ { .compatible = "samsung,exynos4412-pmu" },
+ { .compatible = "samsung,exynos5250-pmu" },
+ {},
+};
+
+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;
+ phys_addr_t phys_addr;
+ const struct of_device_id *matches = exynos_dt_pmu_match;
+
+ for (; matches->compatible[0]; matches++) {
+ if (!of_flat_dt_is_compatible(node, matches->compatible))
+ continue;
+ 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);
+
+ exynos_pmu_base = ioremap(phys_addr, be32_to_cpu(reg[1]));
+ if (WARN_ON(!exynos_pmu_base))
+ return -EFAULT;
+ return 1;
+ }
+
+ return 0;
+}
Is such early mapping really needed? Couldn't the code using PMU be
deferred to the stage that memory management is available and then
of_iomap() used directly?
+
/*
* exynos_map_io
*
@@ -302,6 +346,7 @@ static void __init exynos_init_io(void)
debug_ll_io_init();
of_scan_flat_dt(exynos_fdt_map_chipid, NULL);
+ of_scan_flat_dt(exynos_fdt_map_pmu, NULL);
/* detect cpu id and rev. */
s5p_init_cpu(S5P_VA_CHIPID);
@@ -336,6 +381,38 @@ static int __init exynos4_l2x0_cache_init(void)
}
early_initcall(exynos4_l2x0_cache_init);
+
+inline struct regmap *get_exynos_pmuregmap()
+{
+ return exynos_pmu_regmap;
+}
+
+inline void __iomem *get_exynos_pmuaddr()
+{
+ return exynos_pmu_base;
+}
Hmm, non-static inline inside a C file? Probably should be either static
inline or non-static non-inline. (Assuming that both are really needed,
as I pointed in the comments above.)
+
+
+void __init exynos_map_pmu(void)
+{
+ struct device_node *np = NULL;
+
+ early_syscon_init();
+
+ np = of_find_matching_node(NULL, exynos_dt_pmu_match);
+
+ if (!np) {
+ pr_err("Failed to find PMU node\n");
+ return;
+ } else {
+ exynos_pmu_regmap = syscon_early_regmap_lookup_by_phandle(np,
+ "samsung,syscon-phandle");
Do you need this regmap really here? I believe it should be the code
using PMU registers which calls this function directly to retrieve a
handle to the syscon.
Best regards,
Tomasz
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