ARM: imx: add initial support for imx7ulp

The i.MX 7ULP family of processors features NXP's advanced implementation
of the Arm Cortex-A7 core, the Arm Cortex-M4 core, as well as a 3D and 2D
Graphics Processing Units (GPUs).

This patch aims to add an initial support for imx7ulp. Note that we need
configure power mode to Partial Stop mode 3 with system/bus clock enabled
first as the default enabled STOP mode will gate off system/bus clock when
execute WFI in MX7ULP SoC.

And there's still no MXC_CPU_IMX7ULP IDs read from register as ULP has no
anatop as before. So we encode one with 0xff in reverse order in case new
ones will be in the future.

Cc: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

1 files changed, 29 insertions, 0 deletions

diff --git a/arch/arm/mach-imx/pm-imx7ulp.c b/arch/arm/mach-imx/pm-imx7ulp.c
new file mode 100644
index 000000000000..cf6a380c2b8d
--- /dev/null
+++ b/arch/arm/mach-imx/pm-imx7ulp.c
@@ -0,0 +1,29 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2016 Freescale Semiconductor, Inc.
+ * Copyright 2017-2018 NXP
+ *   Author: Dong Aisheng <aisheng.dong@nxp.com>
+ */
+
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+
+#define SMC_PMCTRL		0x10
+#define BP_PMCTRL_PSTOPO        16
+#define PSTOPO_PSTOP3		0x3
+
+void __init imx7ulp_pm_init(void)
+{
+	struct device_node *np;
+	void __iomem *smc1_base;
+
+	np = of_find_compatible_node(NULL, NULL, "fsl,imx7ulp-smc1");
+	smc1_base = of_iomap(np, 0);
+	WARN_ON(!smc1_base);
+
+	/* Partial Stop mode 3 with system/bus clock enabled */
+	writel_relaxed(PSTOPO_PSTOP3 << BP_PMCTRL_PSTOPO,
+		       smc1_base + SMC_PMCTRL);
+	iounmap(smc1_base);
+}