MXC: Add iomux support for MX35 SoCs

This iomux is called iomux-v3 in the tree because it is the third known
incarnation of MXC iomuxers. It is not only found on the MX35 but also
on the MX51 and probably others.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

arch/arm/mach-mx3/Kconfig

@@ -5,6 +5,7 @@ config ARCH_MX31
 
 config ARCH_MX35
 	bool
+	select ARCH_MXC_IOMUX_V3
 
 comment "MX3 platforms:"
 

arch/arm/plat-mxc/Kconfig

@@ -51,4 +51,6 @@ config MXC_PWM
 	help
 	  Enable support for the i.MX PWM controller(s).
 
+config ARCH_MXC_IOMUX_V3
+	bool
 endif

arch/arm/plat-mxc/Makefile

@@ -7,4 +7,5 @@ obj-y := irq.o clock.o gpio.o time.o devices.o cpu.o system.o
 
 obj-$(CONFIG_ARCH_MX1) += iomux-mx1-mx2.o dma-mx1-mx2.o
 obj-$(CONFIG_ARCH_MX2) += iomux-mx1-mx2.o dma-mx1-mx2.o
+obj-$(CONFIG_ARCH_MXC_IOMUX_V3) += iomux-v3.o
 obj-$(CONFIG_MXC_PWM)  += pwm.o

arch/arm/plat-mxc/include/mach/iomux-v3.h

@@ -0,0 +1,121 @@
+/*
+ * Copyright (C) 2009 by Jan Weitzel Phytec Messtechnik GmbH,
+ *			<armlinux@phytec.de>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ */
+
+#ifndef __MACH_IOMUX_V3_H__
+#define __MACH_IOMUX_V3_H__
+
+/*
+ *	build IOMUX_PAD structure
+ *
+ * This iomux scheme is based around pads, which are the physical balls
+ * on the processor.
+ *
+ * - Each pad has a pad control register (IOMUXC_SW_PAD_CTRL_x) which controls
+ *   things like driving strength and pullup/pulldown.
+ * - Each pad can have but not necessarily does have an output routing register
+ *   (IOMUXC_SW_MUX_CTL_PAD_x).
+ * - Each pad can have but not necessarily does have an input routing register
+ *   (IOMUXC_x_SELECT_INPUT)
+ *
+ * The three register sets do not have a fixed offset to each other,
+ * hence we order this table by pad control registers (which all pads
+ * have) and put the optional i/o routing registers into additional
+ * fields.
+ *
+ * The naming convention for the pad modes is MX35_PAD_<padname>__<padmode>
+ * If <padname> or <padmode> refers to a GPIO, it is named
+ * GPIO_<unit>_<num>
+ *
+ */
+
+struct pad_desc {
+	unsigned mux_ctrl_ofs:12; /* IOMUXC_SW_MUX_CTL_PAD offset */
+	unsigned mux_mode:8;
+	unsigned pad_ctrl_ofs:12; /* IOMUXC_SW_PAD_CTRL offset */
+#define	NO_PAD_CTRL	(1 << 16)
+	unsigned pad_ctrl:17;
+	unsigned select_input_ofs:12; /* IOMUXC_SELECT_INPUT offset */
+	unsigned select_input:3;
+};
+
+#define IOMUX_PAD(_pad_ctrl_ofs, _mux_ctrl_ofs, _mux_mode, _select_input_ofs, \
+		_select_input, _pad_ctrl)				\
+		{							\
+			.mux_ctrl_ofs     = _mux_ctrl_ofs,		\
+			.mux_mode         = _mux_mode,			\
+			.pad_ctrl_ofs     = _pad_ctrl_ofs,		\
+			.pad_ctrl         = _pad_ctrl,			\
+			.select_input_ofs = _select_input_ofs,		\
+			.select_input     = _select_input,		\
+		}
+
+/*
+ * Use to set PAD control
+ */
+#define PAD_CTL_DRIVE_VOLTAGE_3_3_V	0
+#define PAD_CTL_DRIVE_VOLTAGE_1_8_V	1
+
+#define PAD_CTL_NO_HYSTERESIS		0
+#define PAD_CTL_HYSTERESIS		1
+
+#define PAD_CTL_PULL_DISABLED		0x0
+#define PAD_CTL_PULL_KEEPER		0xa
+#define PAD_CTL_PULL_DOWN_100K		0xc
+#define PAD_CTL_PULL_UP_47K		0xd
+#define PAD_CTL_PULL_UP_100K		0xe
+#define PAD_CTL_PULL_UP_22K		0xf
+
+#define PAD_CTL_OUTPUT_CMOS		0
+#define PAD_CTL_OUTPUT_OPEN_DRAIN	1
+
+#define PAD_CTL_DRIVE_STRENGTH_NORM	0
+#define PAD_CTL_DRIVE_STRENGTH_HIGH	1
+#define PAD_CTL_DRIVE_STRENGTH_MAX	2
+
+#define PAD_CTL_SLEW_RATE_SLOW		0
+#define PAD_CTL_SLEW_RATE_FAST		1
+
+/*
+ * setups a single pad:
+ * 	- reserves the pad so that it is not claimed by another driver
+ * 	- setups the iomux according to the configuration
+ */
+int mxc_iomux_v3_setup_pad(struct pad_desc *pad);
+
+/*
+ * setups mutliple pads
+ * convenient way to call the above function with tables
+ */
+int mxc_iomux_v3_setup_multiple_pads(struct pad_desc *pad_list, unsigned count);
+
+/*
+ * releases a single pad:
+ * 	- make it available for a future use by another driver
+ * 	- DOES NOT reconfigure the IOMUX in its reset state
+ */
+void mxc_iomux_v3_release_pad(struct pad_desc *pad);
+
+/*
+ * releases multiple pads
+ * convenvient way to call the above function with tables
+ */
+void mxc_iomux_v3_release_multiple_pads(struct pad_desc *pad_list, int count);
+
+#endif /* __MACH_IOMUX_V3_H__*/
+

arch/arm/plat-mxc/iomux-v3.c

@@ -0,0 +1,98 @@
+/*
+ * Copyright 2004-2006 Freescale Semiconductor, Inc. All Rights Reserved.
+ * Copyright (C) 2008 by Sascha Hauer <kernel@pengutronix.de>
+ * Copyright (C) 2009 by Jan Weitzel Phytec Messtechnik GmbH,
+ *                       <armlinux@phytec.de>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ */
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/gpio.h>
+
+#include <mach/hardware.h>
+#include <asm/mach/map.h>
+#include <mach/iomux-v3.h>
+
+#define IOMUX_BASE	IO_ADDRESS(IOMUXC_BASE_ADDR)
+
+static unsigned long iomux_v3_pad_alloc_map[0x200 / BITS_PER_LONG];
+
+/*
+ * setups a single pin:
+ * 	- reserves the pin so that it is not claimed by another driver
+ * 	- setups the iomux according to the configuration
+ */
+int mxc_iomux_v3_setup_pad(struct pad_desc *pad)
+{
+	unsigned int pad_ofs = pad->pad_ctrl_ofs;
+
+	if (test_and_set_bit(pad_ofs >> 2, iomux_v3_pad_alloc_map))
+		return -EBUSY;
+	if (pad->mux_ctrl_ofs)
+		__raw_writel(pad->mux_mode, IOMUX_BASE + pad->mux_ctrl_ofs);
+
+	if (pad->select_input_ofs)
+		__raw_writel(pad->select_input,
+				IOMUX_BASE + pad->select_input_ofs);
+
+	if (!(pad->pad_ctrl & NO_PAD_CTRL))
+		__raw_writel(pad->pad_ctrl, IOMUX_BASE + pad->pad_ctrl_ofs);
+	return 0;
+}
+EXPORT_SYMBOL(mxc_iomux_v3_setup_pad);
+
+int mxc_iomux_v3_setup_multiple_pads(struct pad_desc *pad_list, unsigned count)
+{
+	struct pad_desc *p = pad_list;
+	int i;
+	int ret;
+
+	for (i = 0; i < count; i++) {
+		ret = mxc_iomux_v3_setup_pad(p);
+		if (ret)
+			goto setup_error;
+		p++;
+	}
+	return 0;
+
+setup_error:
+	mxc_iomux_v3_release_multiple_pads(pad_list, i);
+	return ret;
+}
+EXPORT_SYMBOL(mxc_iomux_v3_setup_multiple_pads);
+
+void mxc_iomux_v3_release_pad(struct pad_desc *pad)
+{
+	unsigned int pad_ofs = pad->pad_ctrl_ofs;
+
+	clear_bit(pad_ofs >> 2, iomux_v3_pad_alloc_map);
+}
+EXPORT_SYMBOL(mxc_iomux_v3_release_pad);
+
+void mxc_iomux_v3_release_multiple_pads(struct pad_desc *pad_list, int count)
+{
+	struct pad_desc *p = pad_list;
+	int i;
+
+	for (i = 0; i < count; i++) {
+		mxc_iomux_v3_release_pad(p);
+		p++;
+	}
+}
+EXPORT_SYMBOL(mxc_iomux_v3_release_multiple_pads);