Add driver for IDE like interfaces

This simple driver enables a generic driver for ATA type of devices to get
access to the so called 'register file' of an ATA drive.

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

drivers/ata/Kconfig

@@ -32,4 +32,11 @@ config DISK_ATA
 
 comment "interface types"
 
+config DISK_INTF_PLATFORM_IDE
+	bool "Platform IDE"
+	select DISK_ATA
+	help
+	  Generic platform driver for simple IDE like interfaces to a connected
+	  ATA device.
+
 endif

drivers/ata/Makefile

@@ -5,3 +5,4 @@ obj-$(CONFIG_DISK_ATA) += disk_ata_drive.o
 
 # interface types
 
+obj-$(CONFIG_DISK_INTF_PLATFORM_IDE) += intf_platform_ide.o

drivers/ata/intf_platform_ide.c

@@ -0,0 +1,130 @@
+/*
+ * Copyright (C) 2011 Juergen Beisert, Pengutronix
+ *
+ * Derived from the Linux kernel: Generic platform device PATA driver
+ *  Copyright (C) 2006 - 2007  Paul Mundt
+ *  Based on pata_pcmcia:
+ *  Copyright 2005-2006 Red Hat Inc, all rights reserved.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * 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.
+ */
+
+#include <common.h>
+#include <init.h>
+#include <xfuncs.h>
+#include <malloc.h>
+#include <errno.h>
+#include <ata_drive.h>
+#include <platform_ide.h>
+
+/**
+ * Setup the register specific addresses for an ATA like divice
+ * @param reg_base Base address of the standard ATA like registers
+ * @param alt_base Base address of the alternate ATA like registers
+ * @param ioaddr Register file structure to setup
+ * @param shift Shift offset between registers
+ *
+ * Some of the registers have different names but use the same offset. This is
+ * due to the fact read or write access at the same offset reaches different
+ * registers.
+ */
+static void platform_ide_setup_port(void *reg_base, void *alt_base,
+			struct ata_ioports *ioaddr, unsigned shift)
+{
+	/* standard registers (0 ... 7) */
+	ioaddr->cmd_addr = reg_base;
+
+	ioaddr->data_addr = reg_base + (IDE_REG_DATA << shift);
+
+	ioaddr->error_addr = reg_base + (IDE_REG_ERR << shift);
+	ioaddr->feature_addr = reg_base + (IDE_REG_FEATURE << shift);
+
+	ioaddr->nsect_addr = reg_base + (IDE_REG_NSECT << shift);
+
+	ioaddr->lbal_addr = reg_base + (IDE_REG_LBAL << shift);
+
+	ioaddr->lbam_addr = reg_base + (IDE_REG_LBAM << shift);
+
+	ioaddr->lbah_addr = reg_base + (IDE_REG_LBAH << shift);
+
+	ioaddr->device_addr = reg_base + (IDE_REG_DEVICE << shift);
+
+	ioaddr->status_addr = reg_base + (IDE_REG_STATUS << shift);
+	ioaddr->command_addr = reg_base + (IDE_REG_CMD << shift);
+
+	ioaddr->altstatus_addr = alt_base + (IDE_REG_ALT_STATUS << shift);
+	ioaddr->ctl_addr = alt_base + (IDE_REG_DEV_CTL << shift);
+
+	ioaddr->alt_dev_addr = alt_base + (IDE_REG_DRV_ADDR << shift);
+}
+
+static int platform_ide_probe(struct device_d *dev)
+{
+	int rc;
+	struct ide_port_info *pdata = dev->platform_data;
+	struct ata_ioports *io;
+	void *reg_base, *alt_base;
+
+	if (pdata == NULL) {
+		dev_err(dev, "No platform data. Cannot continue\n");
+		return -EINVAL;
+	}
+
+	io = xzalloc(sizeof(struct ata_ioports));
+	reg_base = dev_request_mem_region(dev, 0);
+	alt_base = dev_request_mem_region(dev, 1);
+	platform_ide_setup_port(reg_base, alt_base, io, pdata->ioport_shift);
+	io->reset = pdata->reset;
+	io->dataif_be = pdata->dataif_be;
+
+	rc = register_ata_drive(dev, io);
+	if (rc != 0) {
+		dev_err(dev, "Cannot register IDE interface\n");
+		free(io);
+	}
+
+	return rc;
+}
+
+static struct driver_d platform_ide_driver = {
+	.name   = "ide_intf",
+	.probe  = platform_ide_probe,
+};
+
+static int platform_ide_init(void)
+{
+	return register_driver(&platform_ide_driver);
+}
+
+device_initcall(platform_ide_init);
+
+/**
+ * @file
+ * @brief Interface driver for an ATA drive behind an IDE like interface
+ *
+ * This communication driver does all accesses to the drive via memory IO
+ * instructions.
+ *
+ * This kind of interface is also useable for regular bus like access, when
+ * there is no dedicated IDE available.
+ *
+ * "IDE like" means the platform data defines addresses to the register file
+ * of the attached ATA drive.
+ *
+ * This driver does not change any access timings due to the fact it has no idea
+ * how to do so. So, do not expect an impressive data throughput.
+ *
+ * @todo Support also the IO port access method, the x86 architecture is using
+ */

include/platform_ide.h

@@ -0,0 +1,32 @@
+/*
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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.
+ */
+
+#ifndef __PLATFORM_IDE_H
+#define __PLATFORM_IDE_H
+
+struct ide_port_info {
+	/*
+	 * I/O port shift, for platforms with ports that are
+	 * constantly spaced and need larger than the 1-byte
+	 * spacing
+	 */
+	unsigned ioport_shift;
+	int dataif_be;	/* true if 16 bit data register is big endian */
+
+	/* handle hard reset of this port */
+	void (*reset)(int);	/* true: assert reset, false: de-assert reset */
+};
+
+#endif /* __PLATFORM_IDE_H */