ACPI support for IDE devices

This patch implements ACPI integration for generic IDE devices.
The ACPI spec mandates that some methods are called during suspend and
resume. And consequently there most modern Laptops cannot resume
properly without it.

According to the spec, we should call '_GTM' (Get Timing) upon suspend
to store the current IDE adapter settings.
Upon resume we should call '_STM' (Set Timing) to initialize the
adapter with the stored settings; afterwards '_GTF' (Get Taskfile)
should be called which returns a buffer with some IDE initialisation
commands. Those commands should be passed to the drive.

There are two module params which control the behaviour of this patch:

'ide=noacpi'
	Do not call any ACPI methods (Disables any ACPI method calls)
'ide=acpigtf'
	Enable execution of _GTF methods upon resume.
	Has no effect if 'ide=noacpi' is set.
'ide=acpionboot'
	Enable execution of ACPI methods during boot.
	This might be required on some machines if 'ide=acpigtf' is
	selected as some machines modify the _GTF information
	depending on the drive identification passed down with _STM.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

drivers/ide/Kconfig

@@ -271,6 +271,13 @@ config BLK_DEV_IDESCSI
 	  If both this SCSI emulation and native ATAPI support are compiled
 	  into the kernel, the native support will be used.
 
+config BLK_DEV_IDEACPI
+	bool "IDE ACPI support"
+	depends on ACPI
+	---help---
+	  Implement ACPI support for generic IDE devices. On modern
+	  machines ACPI support is required to properly handle ACPI S3 states.
+
 config IDE_TASK_IOCTL
 	bool "IDE Taskfile Access"
 	help

drivers/ide/Makefile

@@ -22,6 +22,7 @@ ide-core-$(CONFIG_BLK_DEV_IDEPCI)	+= setup-pci.o
 ide-core-$(CONFIG_BLK_DEV_IDEDMA)	+= ide-dma.o
 ide-core-$(CONFIG_PROC_FS)		+= ide-proc.o
 ide-core-$(CONFIG_BLK_DEV_IDEPNP)	+= ide-pnp.o
+ide-core-$(CONFIG_BLK_DEV_IDEACPI)	+= ide-acpi.o
 
 # built-in only drivers from arm/
 ide-core-$(CONFIG_IDE_ARM)		+= arm/ide_arm.o

drivers/ide/ide-probe.c

@@ -1384,6 +1384,9 @@ static int hwif_init(ide_hwif_t *hwif)
 
 done:
 	init_gendisk(hwif);
+
+	ide_acpi_init(hwif);
+
 	hwif->present = 1;	/* success */
 	return 1;
 

drivers/ide/ide.c

@@ -187,6 +187,12 @@ int noautodma = 1;
 
 EXPORT_SYMBOL(noautodma);
 
+#ifdef CONFIG_BLK_DEV_IDEACPI
+int ide_noacpi = 0;
+int ide_noacpitfs = 1;
+int ide_noacpionboot = 1;
+#endif
+
 /*
  * This is declared extern in ide.h, for access by other IDE modules:
  */
@@ -1214,10 +1220,15 @@ EXPORT_SYMBOL(system_bus_clock);
 static int generic_ide_suspend(struct device *dev, pm_message_t mesg)
 {
 	ide_drive_t *drive = dev->driver_data;
+	ide_hwif_t *hwif = HWIF(drive);
 	struct request rq;
 	struct request_pm_state rqpm;
 	ide_task_t args;
 
+	/* Call ACPI _GTM only once */
+	if (!(drive->dn % 2))
+		ide_acpi_get_timing(hwif);
+
 	memset(&rq, 0, sizeof(rq));
 	memset(&rqpm, 0, sizeof(rqpm));
 	memset(&args, 0, sizeof(args));
@@ -1235,10 +1246,17 @@ static int generic_ide_suspend(struct device *dev, pm_message_t mesg)
 static int generic_ide_resume(struct device *dev)
 {
 	ide_drive_t *drive = dev->driver_data;
+	ide_hwif_t *hwif = HWIF(drive);
 	struct request rq;
 	struct request_pm_state rqpm;
 	ide_task_t args;
 
+	/* Call ACPI _STM only once */
+	if (!(drive->dn % 2))
+		ide_acpi_push_timing(hwif);
+
+	ide_acpi_exec_tfs(drive);
+
 	memset(&rq, 0, sizeof(rq));
 	memset(&rqpm, 0, sizeof(rqpm));
 	memset(&args, 0, sizeof(args));
@@ -1543,6 +1561,24 @@ static int __init ide_setup(char *s)
 	}
 #endif /* CONFIG_BLK_DEV_IDEPCI */
 
+#ifdef CONFIG_BLK_DEV_IDEACPI
+	if (!strcmp(s, "ide=noacpi")) {
+		//printk(" : Disable IDE ACPI support.\n");
+		ide_noacpi = 1;
+		return 1;
+	}
+	if (!strcmp(s, "ide=acpigtf")) {
+		//printk(" : Enable IDE ACPI _GTF support.\n");
+		ide_noacpitfs = 0;
+		return 1;
+	}
+	if (!strcmp(s, "ide=acpionboot")) {
+		//printk(" : Call IDE ACPI methods on boot.\n");
+		ide_noacpionboot = 0;
+		return 1;
+	}
+#endif /* CONFIG_BLK_DEV_IDEACPI */
+
 	/*
 	 * Look for drive options:  "hdx="
 	 */

include/linux/ide.h

@@ -18,6 +18,9 @@
 #include <linux/device.h>
 #include <linux/pci.h>
 #include <linux/completion.h>
+#ifdef CONFIG_BLK_DEV_IDEACPI
+#include <acpi/acpi.h>
+#endif
 #include <asm/byteorder.h>
 #include <asm/system.h>
 #include <asm/io.h>
@@ -541,6 +544,11 @@ typedef enum {
 struct ide_driver_s;
 struct ide_settings_s;
 
+#ifdef CONFIG_BLK_DEV_IDEACPI
+struct ide_acpi_drive_link;
+struct ide_acpi_hwif_link;
+#endif
+
 typedef struct ide_drive_s {
 	char		name[4];	/* drive name, such as "hda" */
         char            driver_req[10];	/* requests specific driver */
@@ -637,6 +645,9 @@ typedef struct ide_drive_s {
 
 	int		lun;		/* logical unit */
 	int		crc_count;	/* crc counter to reduce drive speed */
+#ifdef CONFIG_BLK_DEV_IDEACPI
+	struct ide_acpi_drive_link *acpidata;
+#endif
 	struct list_head list;
 	struct device	gendev;
 	struct completion gendev_rel_comp;	/* to deal with device release() */
@@ -804,6 +815,10 @@ typedef struct hwif_s {
 	void		*hwif_data;	/* extra hwif data */
 
 	unsigned dma;
+
+#ifdef CONFIG_BLK_DEV_IDEACPI
+	struct ide_acpi_hwif_link *acpidata;
+#endif
 } ____cacheline_internodealigned_in_smp ide_hwif_t;
 
 /*
@@ -1298,6 +1313,18 @@ static inline void ide_dma_verbose(ide_drive_t *drive) { ; }
 static inline void ide_release_dma(ide_hwif_t *drive) {;}
 #endif
 
+#ifdef CONFIG_BLK_DEV_IDEACPI
+extern int ide_acpi_exec_tfs(ide_drive_t *drive);
+extern void ide_acpi_get_timing(ide_hwif_t *hwif);
+extern void ide_acpi_push_timing(ide_hwif_t *hwif);
+extern void ide_acpi_init(ide_hwif_t *hwif);
+#else
+static inline int ide_acpi_exec_tfs(ide_drive_t *drive) { return 0; }
+static inline void ide_acpi_get_timing(ide_hwif_t *hwif) { ; }
+static inline void ide_acpi_push_timing(ide_hwif_t *hwif) { ; }
+static inline void ide_acpi_init(ide_hwif_t *hwif) { ; }
+#endif
+
 extern int ide_hwif_request_regions(ide_hwif_t *hwif);
 extern void ide_hwif_release_regions(ide_hwif_t* hwif);
 extern void ide_unregister (unsigned int index);