imx8: add iomux configuration api

Add iomux configuration api.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Anatolij Gustschin <agust@denx.de>
Cc: Stefano Babic <sbabic@denx.de>

arch/arm/include/asm/arch-imx8/iomux.h

@@ -0,0 +1,40 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright 2018 NXP
+ */
+
+#ifndef __ASM_ARCH_IMX8_IOMUX_H__
+#define __ASM_ARCH_IMX8_IOMUX_H__
+
+/*
+ * We use 64bits value for iomux settings.
+ * High 32bits are used for padring register value,
+ * low 16bits are used for pin index.
+ */
+typedef u64 iomux_cfg_t;
+
+#define PADRING_IFMUX_EN_SHIFT		31
+#define PADRING_IFMUX_EN_MASK		BIT(31)
+#define PADRING_GP_EN_SHIFT		30
+#define PADRING_GP_EN_MASK		BIT(30)
+#define PADRING_IFMUX_SHIFT		27
+#define PADRING_IFMUX_MASK		GENMASK(29, 27)
+#define PADRING_CONFIG_SHIFT		25
+#define PADRING_LPCONFIG_SHIFT		23
+#define PADRING_PULL_SHIFT		5
+#define PADRING_DSE_SHIFT		0
+
+#define MUX_PAD_CTRL_SHIFT	32
+#define MUX_PAD_CTRL_MASK	((iomux_cfg_t)0xFFFFFFFF << MUX_PAD_CTRL_SHIFT)
+#define MUX_PAD_CTRL(x)		((iomux_cfg_t)(x) << MUX_PAD_CTRL_SHIFT)
+#define MUX_MODE_SHIFT		(PADRING_IFMUX_SHIFT + MUX_PAD_CTRL_SHIFT)
+#define MUX_MODE_MASK		((iomux_cfg_t)0x7 << MUX_MODE_SHIFT)
+#define PIN_ID_MASK		((iomux_cfg_t)0xFFFF)
+
+/* Valid mux alt0 to alt7 */
+#define MUX_MODE_ALT(x)		(((iomux_cfg_t)(x) << MUX_MODE_SHIFT) & \
+				 MUX_MODE_MASK)
+
+void imx8_iomux_setup_pad(iomux_cfg_t pad);
+void imx8_iomux_setup_multiple_pads(iomux_cfg_t const *pad_list, u32 count);
+#endif	/* __ASM_ARCH_IMX8_IOMUX_H__ */

arch/arm/mach-imx/imx8/Makefile

@@ -4,4 +4,4 @@
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
-obj-y += cpu.o
+obj-y += cpu.o iomux.o

arch/arm/mach-imx/imx8/iomux.c

@@ -0,0 +1,43 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2018 NXP
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/arch/iomux.h>
+#include <asm/arch/sci/sci.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/*
+ * configures a single pad in the iomuxer
+ */
+void imx8_iomux_setup_pad(iomux_cfg_t pad)
+{
+	sc_pad_t pin_id = pad & PIN_ID_MASK;
+	int ret;
+
+	u32 val = (u32)((pad & MUX_PAD_CTRL_MASK) >> MUX_PAD_CTRL_SHIFT);
+
+	val |= PADRING_IFMUX_EN_MASK;
+	val |= PADRING_GP_EN_MASK;
+
+	ret = sc_pad_set(-1, pin_id, val);
+	if (ret)
+		printf("sc_pad_set failed!, pin: %u, val: 0x%x\n", pin_id, val);
+
+	debug("iomux: pin %d, val = 0x%x\n", pin_id, val);
+}
+
+/* configures a list of pads within declared with IOMUX_PADS macro */
+void imx8_iomux_setup_multiple_pads(iomux_cfg_t const *pad_list, u32 count)
+{
+	iomux_cfg_t const *p = pad_list;
+	int i;
+
+	for (i = 0; i < count; i++) {
+		imx8_iomux_setup_pad(*p);
+		p++;
+	}
+}