[RFC PATCH v2 30/31] kvx: Add power controller driver

[Yann Sionneau <ysionneau@kalray.eu>]

From: Jules Maselbas <jmaselbas@kalray.eu>

The Power Controller (pwr-ctrl) control cores reset and wake-up
procedure.

Co-developed-by: Clement Leger <clement@clement-leger.fr>
Signed-off-by: Clement Leger <clement@clement-leger.fr>
Co-developed-by: Julian Vetter <jvetter@kalray.eu>
Signed-off-by: Julian Vetter <jvetter@kalray.eu>
Co-developed-by: Louis Morhet <lmorhet@kalray.eu>
Signed-off-by: Louis Morhet <lmorhet@kalray.eu>
Co-developed-by: Marius Gligor <mgligor@kalray.eu>
Signed-off-by: Marius Gligor <mgligor@kalray.eu>
Signed-off-by: Jules Maselbas <jmaselbas@kalray.eu>
Signed-off-by: Yann Sionneau <ysionneau@kalray.eu>
---

Notes:
    V1 -> V2: new patch

 arch/kvx/include/asm/pwr_ctrl.h | 45 ++++++++++++++++
 arch/kvx/platform/Makefile      |  6 +++
 arch/kvx/platform/pwr_ctrl.c    | 91 +++++++++++++++++++++++++++++++++
 3 files changed, 142 insertions(+)
 create mode 100644 arch/kvx/include/asm/pwr_ctrl.h
 create mode 100644 arch/kvx/platform/Makefile
 create mode 100644 arch/kvx/platform/pwr_ctrl.c

diff --git a/arch/kvx/include/asm/pwr_ctrl.h b/arch/kvx/include/asm/pwr_ctrl.h
new file mode 100644
index 000000000000..25f403ba935a
--- /dev/null
+++ b/arch/kvx/include/asm/pwr_ctrl.h
@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2017-2023 Kalray Inc.
+ * Author(s): Clement Leger
+ *            Marius Gligor
+ */
+
+#ifndef _ASM_KVX_PWR_CTRL_H
+#define _ASM_KVX_PWR_CTRL_H
+
+#ifndef __ASSEMBLY__
+
+int kvx_pwr_ctrl_probe(void);
+
+void kvx_pwr_ctrl_cpu_poweron(unsigned int cpu);
+
+#endif
+
+/* Power controller vector register definitions */
+#define KVX_PWR_CTRL_VEC_OFFSET 0x1000
+#define KVX_PWR_CTRL_VEC_WUP_SET_OFFSET     0x10
+#define KVX_PWR_CTRL_VEC_WUP_CLEAR_OFFSET     0x20
+
+/* Power controller PE reset PC register definitions */
+#define KVX_PWR_CTRL_RESET_PC_OFFSET               0x2000
+
+/* Power controller global register definitions */
+#define KVX_PWR_CTRL_GLOBAL_OFFSET 0x4040
+
+#define KVX_PWR_CTRL_GLOBAL_SET_OFFSET     0x10
+#define KVX_PWR_CTRL_GLOBAL_SET_PE_EN_SHIFT           0x1
+
+#define PWR_CTRL_WUP_SET_OFFSET  \
+		(KVX_PWR_CTRL_VEC_OFFSET + \
+		 KVX_PWR_CTRL_VEC_WUP_SET_OFFSET)
+
+#define PWR_CTRL_WUP_CLEAR_OFFSET  \
+		(KVX_PWR_CTRL_VEC_OFFSET + \
+		 KVX_PWR_CTRL_VEC_WUP_CLEAR_OFFSET)
+
+#define PWR_CTRL_GLOBAL_CONFIG_OFFSET \
+		(KVX_PWR_CTRL_GLOBAL_OFFSET + \
+		 KVX_PWR_CTRL_GLOBAL_SET_OFFSET)
+
+#endif /* _ASM_KVX_PWR_CTRL_H */
diff --git a/arch/kvx/platform/Makefile b/arch/kvx/platform/Makefile
new file mode 100644
index 000000000000..c7d0abb15c27
--- /dev/null
+++ b/arch/kvx/platform/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Copyright (C) 2018-2023 Kalray Inc.
+#
+
+obj-$(CONFIG_SMP) += pwr_ctrl.o
diff --git a/arch/kvx/platform/pwr_ctrl.c b/arch/kvx/platform/pwr_ctrl.c
new file mode 100644
index 000000000000..ee35d04845ae
--- /dev/null
+++ b/arch/kvx/platform/pwr_ctrl.c
@@ -0,0 +1,91 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2017-2023 Kalray Inc.
+ * Author(s): Clement Leger
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+
+#include <asm/pwr_ctrl.h>
+#include <asm/symbols.h>
+
+struct kvx_pwr_ctrl {
+	void __iomem *regs;
+};
+
+static struct kvx_pwr_ctrl kvx_pwr_controller;
+
+/**
+ * kvx_pwr_ctrl_cpu_poweron() - Wakeup a cpu
+ * @cpu: cpu to wakeup
+ */
+void kvx_pwr_ctrl_cpu_poweron(unsigned int cpu)
+{
+	/* Set PE boot address */
+	writeq((unsigned long long)kvx_start,
+			kvx_pwr_controller.regs + KVX_PWR_CTRL_RESET_PC_OFFSET);
+	/* Wake up processor ! */
+	writeq(1ULL << cpu,
+	       kvx_pwr_controller.regs + PWR_CTRL_WUP_SET_OFFSET);
+	/* Then clear wakeup to allow processor to sleep */
+	writeq(1ULL << cpu,
+	       kvx_pwr_controller.regs + PWR_CTRL_WUP_CLEAR_OFFSET);
+}
+
+static struct device_node * __init get_pwr_ctrl_node(void)
+{
+	const phandle *ph;
+	struct device_node *cpu;
+	struct device_node *node;
+
+	cpu = of_get_cpu_node(raw_smp_processor_id(), NULL);
+	if (!cpu) {
+		pr_err("Failed to get CPU node\n");
+		return NULL;
+	}
+
+	ph = of_get_property(cpu, "power-controller", NULL);
+	if (!ph) {
+		pr_err("Failed to get power-controller phandle\n");
+		return NULL;
+	}
+
+	node = of_find_node_by_phandle(be32_to_cpup(ph));
+	if (!node) {
+		pr_err("Failed to get power-controller node\n");
+		return NULL;
+	}
+
+	return node;
+}
+
+int __init kvx_pwr_ctrl_probe(void)
+{
+	struct device_node *ctrl;
+
+	ctrl = get_pwr_ctrl_node();
+	if (!ctrl) {
+		pr_err("Failed to get power controller node\n");
+		return -EINVAL;
+	}
+
+	if (!of_device_is_compatible(ctrl, "kalray,kvx-pwr-ctrl")) {
+		pr_err("Failed to get power controller node\n");
+		return -EINVAL;
+	}
+
+	kvx_pwr_controller.regs = of_iomap(ctrl, 0);
+	if (!kvx_pwr_controller.regs) {
+		pr_err("Failed ioremap\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
-- 
2.37.2