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authorBrendan Higgins <brendanhiggins@google.com>2017-08-16 22:18:39 +0300
committerArnd Bergmann <arnd@arndb.de>2018-03-06 19:54:23 +0300
commit7bffa14c9aed5f788d3126271f0fd8758fbd129e (patch)
tree94bc11ab69c834126df570fee3c1b31b673f6de0 /arch/arm/mach-npcm/platsmp.c
parent6a498e06ba22872d3a27cc0dae77b9314b1de48b (diff)
downloadlinux-7bffa14c9aed5f788d3126271f0fd8758fbd129e.tar.xz
arm: npcm: add basic support for Nuvoton BMCs
Adds basic support for the Nuvoton NPCM750 BMC. Signed-off-by: Brendan Higgins <brendanhiggins@google.com> Reviewed-by: Tomer Maimon <tmaimon77@gmail.com> Reviewed-by: Avi Fishman <avifishman70@gmail.com> Tested-by: Tomer Maimon <tmaimon77@gmail.com> Tested-by: Avi Fishman <avifishman70@gmail.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'arch/arm/mach-npcm/platsmp.c')
-rw-r--r--arch/arm/mach-npcm/platsmp.c81
1 files changed, 81 insertions, 0 deletions
diff --git a/arch/arm/mach-npcm/platsmp.c b/arch/arm/mach-npcm/platsmp.c
new file mode 100644
index 000000000000..21633c70fe7f
--- /dev/null
+++ b/arch/arm/mach-npcm/platsmp.c
@@ -0,0 +1,81 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2018 Nuvoton Technology corporation.
+// Copyright 2018 Google, Inc.
+
+#define pr_fmt(fmt) "nuvoton,npcm7xx-smp: " fmt
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/smp.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+#include <linux/of_address.h>
+#include <asm/cacheflush.h>
+#include <asm/smp.h>
+#include <asm/smp_plat.h>
+#include <asm/smp_scu.h>
+
+#define NPCM7XX_SCRPAD_REG 0x13c
+
+extern void npcm7xx_secondary_startup(void);
+
+static int npcm7xx_smp_boot_secondary(unsigned int cpu,
+ struct task_struct *idle)
+{
+ struct device_node *gcr_np;
+ void __iomem *gcr_base;
+ int ret = 0;
+
+ gcr_np = of_find_compatible_node(NULL, NULL, "nuvoton,npcm750-gcr");
+ if (!gcr_np) {
+ pr_err("no gcr device node\n");
+ ret = -ENODEV;
+ goto out;
+ }
+ gcr_base = of_iomap(gcr_np, 0);
+ if (!gcr_base) {
+ pr_err("could not iomap gcr");
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ /* give boot ROM kernel start address. */
+ iowrite32(__pa_symbol(npcm7xx_secondary_startup), gcr_base +
+ NPCM7XX_SCRPAD_REG);
+ /* make sure the previous write is seen by all observers. */
+ dsb_sev();
+
+ iounmap(gcr_base);
+out:
+ return ret;
+}
+
+static void __init npcm7xx_smp_prepare_cpus(unsigned int max_cpus)
+{
+ struct device_node *scu_np;
+ void __iomem *scu_base;
+
+ scu_np = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu");
+ if (!scu_np) {
+ pr_err("no scu device node\n");
+ return;
+ }
+ scu_base = of_iomap(scu_np, 0);
+ if (!scu_base) {
+ pr_err("could not iomap scu");
+ return;
+ }
+
+ scu_enable(scu_base);
+
+ iounmap(scu_base);
+}
+
+static struct smp_operations npcm7xx_smp_ops __initdata = {
+ .smp_prepare_cpus = npcm7xx_smp_prepare_cpus,
+ .smp_boot_secondary = npcm7xx_smp_boot_secondary,
+};
+
+CPU_METHOD_OF_DECLARE(npcm7xx_smp, "nuvoton,npcm750-smp", &npcm7xx_smp_ops);