Many platforms are duplicating code for enabling SCU, lets add
common code to enable SCU by parsing SCU device node so the duplication
in each platform can be avoided.
CC: Krzysztof Kozlowski <k...@kernel.org>
CC: Jisheng Zhang <jszh...@marvell.com>
CC: Russell King <li...@armlinux.org.uk>
CC: Dinh Nguyen <dingu...@opensource.altera.com>
CC: Patrice Chotard <patrice.chot...@st.com>
CC: Linus Walleij <linus.wall...@linaro.org>
CC: Liviu Dudau <liviu.du...@arm.com>
CC: Ray Jui <r...@broadcom.com>
CC: Stephen Warren <swar...@wwwdotorg.org>
CC: Heiko Stuebner <he...@sntech.de>
CC: Shawn Guo <shawn...@kernel.org>
CC: Michal Simek <michal.si...@xilinx.com>
CC: Wei Xu <xuw...@hisilicon.com>
CC: Andrew Lunn <and...@lunn.ch>
CC: Jun Nie <jun....@linaro.org>
Suggested-by: Arnd Bergmann <a...@arndb.de>
Signed-off-by: Pankaj Dubey <pankaj.du...@samsung.com>
---
arch/arm/include/asm/smp_scu.h | 4 +++
arch/arm/kernel/smp_scu.c | 56 ++++++++++++++++++++++++++++++++++++++++++
2 files changed, 60 insertions(+)
diff --git a/arch/arm/include/asm/smp_scu.h b/arch/arm/include/asm/smp_scu.h
index bfe163c..fdeec07 100644
--- a/arch/arm/include/asm/smp_scu.h
+++ b/arch/arm/include/asm/smp_scu.h
@@ -39,8 +39,12 @@ static inline int scu_power_mode(void __iomem *scu_base,
unsigned int mode)
#if defined(CONFIG_SMP) && defined(CONFIG_HAVE_ARM_SCU)
void scu_enable(void __iomem *scu_base);
+void __iomem *of_scu_get_base(void);
+int of_scu_enable(void);
#else
static inline void scu_enable(void __iomem *scu_base) {}
+static inline void __iomem *of_scu_get_base(void) {return NULL; }
+static inline int of_scu_enable(void) {return 0; }
#endif
#endif
diff --git a/arch/arm/kernel/smp_scu.c b/arch/arm/kernel/smp_scu.c
index 72f9241..d0ac3ed 100644
--- a/arch/arm/kernel/smp_scu.c
+++ b/arch/arm/kernel/smp_scu.c
@@ -10,6 +10,7 @@
*/
#include <linux/init.h>
#include <linux/io.h>
+#include <linux/of_address.h>
#include <asm/smp_plat.h>
#include <asm/smp_scu.h>
@@ -70,6 +71,61 @@ void scu_enable(void __iomem *scu_base)
*/
flush_cache_all();
}
+
+static const struct of_device_id scu_match[] = {
+ { .compatible = "arm,cortex-a9-scu", },
+ { .compatible = "arm,cortex-a5-scu", },
+ { }
+};
+
+/*
+ * Helper API to get SCU base address
+ * In case platform DT do not have SCU node, or iomap fails
+ * this call will fallback and will try to map via call to
+ * scu_a9_get_base.
+ * This will return ownership of scu_base to the caller
+ */
+void __iomem *of_scu_get_base(void)
+{
+ unsigned long base = 0;
+ struct device_node *np;
+ void __iomem *scu_base;
+
+ np = of_find_matching_node(NULL, scu_match);
+ scu_base = of_iomap(np, 0);
+ of_node_put(np);
+ if (!scu_base) {
+ pr_err("%s failed to map scu_base via DT\n", __func__);
+ if (scu_a9_has_base()) {
+ base = scu_a9_get_base();
+ scu_base = ioremap(base, SZ_4K);
+ }
+ if (!scu_base) {
+ pr_err("%s failed to map scu_base\n", __func__);
+ return IOMEM_ERR_PTR(-ENOMEM);
+ }
+ }
+ return scu_base;
+}
+
+/*
+ * Enable SCU via mapping scu_base DT
+ * If scu_base mapped successfully scu will be enabled and in case of
+ * failure if will return non-zero error code
+ */
+int of_scu_enable(void)
+{
+ void __iomem *scu_base;
+
+ scu_base = of_scu_get_base();
+ if (!IS_ERR(scu_base)) {
+ scu_enable(scu_base);
+ iounmap(scu_base);
+ return 0;
+ }
+ return PTR_ERR(scu_base);
+}
+
#endif
/*
--
2.7.4
