/*

   * Provides ACPI support for IDE drives.
   *
   * Copyright (C) 2005 Intel Corp.
   * Copyright (C) 2005 Randy Dunlap
   * Copyright (C) 2006 SUSE Linux Products GmbH
   * Copyright (C) 2006 Hannes Reinecke
   */
  
  #include <linux/ata.h>
  #include <linux/delay.h>
  #include <linux/device.h>
  #include <linux/errno.h>
  #include <linux/kernel.h>

  #include <linux/slab.h>

  #include <acpi/acpi.h>
  #include <linux/ide.h>
  #include <linux/pci.h>

  #include <linux/dmi.h>

  #include <linux/module.h>

  
  #include <acpi/acpi_bus.h>

  
  #define REGS_PER_GTF		7

  
  struct GTM_buffer {
  	u32	PIO_speed0;
  	u32	DMA_speed0;
  	u32	PIO_speed1;
  	u32	DMA_speed1;
  	u32	GTM_flags;
  };
  
  struct ide_acpi_drive_link {

  	acpi_handle	 obj_handle;
  	u8		 idbuff[512];
  };
  
  struct ide_acpi_hwif_link {
  	ide_hwif_t			*hwif;
  	acpi_handle			 obj_handle;
  	struct GTM_buffer		 gtm;
  	struct ide_acpi_drive_link	 master;
  	struct ide_acpi_drive_link	 slave;
  };
  
  #undef DEBUGGING
  /* note: adds function name and KERN_DEBUG */
  #ifdef DEBUGGING
  #define DEBPRINT(fmt, args...)	\

  		printk(KERN_DEBUG "%s: " fmt, __func__, ## args)

  #else
  #define DEBPRINT(fmt, args...)	do {} while (0)
  #endif	/* DEBUGGING */

  static bool ide_noacpi;

  module_param_named(noacpi, ide_noacpi, bool, 0);
  MODULE_PARM_DESC(noacpi, "disable IDE ACPI support");

  static bool ide_acpigtf;

  module_param_named(acpigtf, ide_acpigtf, bool, 0);
  MODULE_PARM_DESC(acpigtf, "enable IDE ACPI _GTF support");

  static bool ide_acpionboot;

  module_param_named(acpionboot, ide_acpionboot, bool, 0);
  MODULE_PARM_DESC(acpionboot, "call IDE ACPI methods on boot");

  static bool ide_noacpi_psx;
  static int no_acpi_psx(const struct dmi_system_id *id)
  {
  	ide_noacpi_psx = true;
  	printk(KERN_NOTICE"%s detected - disable ACPI _PSx.
  ", id->ident);
  	return 0;
  }
  
  static const struct dmi_system_id ide_acpi_dmi_table[] = {
  	/* Bug 9673. */
  	/* We should check if this is because ACPI NVS isn't save/restored. */
  	{
  		.callback = no_acpi_psx,
  		.ident    = "HP nx9005",
  		.matches  = {
  			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies Ltd."),
  			DMI_MATCH(DMI_BIOS_VERSION, "KAM1.60")
  		},
  	},

  
  	{ }	/* terminate list */

  };

  int ide_acpi_init(void)

  {

  	dmi_check_system(ide_acpi_dmi_table);
  	return 0;
  }

  bool ide_port_acpi(ide_hwif_t *hwif)
  {
  	return ide_noacpi == 0 && hwif->acpidata;
  }

  /**
   * ide_get_dev_handle - finds acpi_handle and PCI device.function
   * @dev: device to locate
   * @handle: returned acpi_handle for @dev
   * @pcidevfn: return PCI device.func for @dev
   *
   * Returns the ACPI object handle to the corresponding PCI device.
   *
   * Returns 0 on success, <0 on error.
   */
  static int ide_get_dev_handle(struct device *dev, acpi_handle *handle,

  			       u64 *pcidevfn)

  {
  	struct pci_dev *pdev = to_pci_dev(dev);
  	unsigned int bus, devnum, func;

  	u64 addr;

  	acpi_handle dev_handle;

  	acpi_status status;
  	struct acpi_device_info	*dinfo = NULL;
  	int ret = -ENODEV;
  
  	bus = pdev->bus->number;
  	devnum = PCI_SLOT(pdev->devfn);
  	func = PCI_FUNC(pdev->devfn);
  	/* ACPI _ADR encoding for PCI bus: */

  	addr = (u64)(devnum << 16 | func);

  
  	DEBPRINT("ENTER: pci %02x:%02x.%01x
  ", bus, devnum, func);
  
  	dev_handle = DEVICE_ACPI_HANDLE(dev);
  	if (!dev_handle) {
  		DEBPRINT("no acpi handle for device
  ");
  		goto err;
  	}

  	status = acpi_get_object_info(dev_handle, &dinfo);

  	if (ACPI_FAILURE(status)) {
  		DEBPRINT("get_object_info for device failed
  ");
  		goto err;
  	}

  	if (dinfo && (dinfo->valid & ACPI_VALID_ADR) &&
  	    dinfo->address == addr) {
  		*pcidevfn = addr;
  		*handle = dev_handle;
  	} else {
  		DEBPRINT("get_object_info for device has wrong "
  			" address: %llu, should be %u
  ",
  			dinfo ? (unsigned long long)dinfo->address : -1ULL,
  			(unsigned int)addr);
  		goto err;
  	}
  
  	DEBPRINT("for dev=0x%x.%x, addr=0x%llx, *handle=0x%p
  ",
  		 devnum, func, (unsigned long long)addr, *handle);
  	ret = 0;
  err:
  	kfree(dinfo);
  	return ret;
  }
  
  /**
   * ide_acpi_hwif_get_handle - Get ACPI object handle for a given hwif
   * @hwif: device to locate
   *
   * Retrieves the object handle for a given hwif.
   *
   * Returns handle on success, 0 on error.
   */
  static acpi_handle ide_acpi_hwif_get_handle(ide_hwif_t *hwif)
  {
  	struct device		*dev = hwif->gendev.parent;

  	acpi_handle		uninitialized_var(dev_handle);

  	u64			pcidevfn;

  	acpi_handle		chan_handle;
  	int			err;
  
  	DEBPRINT("ENTER: device %s
  ", hwif->name);
  
  	if (!dev) {
  		DEBPRINT("no PCI device for %s
  ", hwif->name);
  		return NULL;
  	}
  
  	err = ide_get_dev_handle(dev, &dev_handle, &pcidevfn);
  	if (err < 0) {
  		DEBPRINT("ide_get_dev_handle failed (%d)
  ", err);
  		return NULL;
  	}
  
  	/* get child objects of dev_handle == channel objects,
  	 * + _their_ children == drive objects */
  	/* channel is hwif->channel */
  	chan_handle = acpi_get_child(dev_handle, hwif->channel);
  	DEBPRINT("chan adr=%d: handle=0x%p
  ",
  		 hwif->channel, chan_handle);
  
  	return chan_handle;
  }
  
  /**

   * do_drive_get_GTF - get the drive bootup default taskfile settings
   * @drive: the drive for which the taskfile settings should be retrieved
   * @gtf_length: number of bytes of _GTF data returned at @gtf_address
   * @gtf_address: buffer containing _GTF taskfile arrays
   *
   * The _GTF method has no input parameters.
   * It returns a variable number of register set values (registers
   * hex 1F1..1F7, taskfiles).
   * The <variable number> is not known in advance, so have ACPI-CA
   * allocate the buffer as needed and return it, then free it later.
   *
   * The returned @gtf_length and @gtf_address are only valid if the
   * function return value is 0.
   */
  static int do_drive_get_GTF(ide_drive_t *drive,
  		     unsigned int *gtf_length, unsigned long *gtf_address,
  		     unsigned long *obj_loc)
  {
  	acpi_status			status;
  	struct acpi_buffer		output;
  	union acpi_object 		*out_obj;

  	int				err = -ENODEV;

  
  	*gtf_length = 0;
  	*gtf_address = 0UL;
  	*obj_loc = 0UL;

  	if (!drive->acpidata->obj_handle) {

  		DEBPRINT("No ACPI object found for %s
  ", drive->name);
  		goto out;

  	}
  
  	/* Setting up output buffer */
  	output.length = ACPI_ALLOCATE_BUFFER;
  	output.pointer = NULL;	/* ACPI-CA sets this; save/free it later */
  
  	/* _GTF has no input parameters */
  	err = -EIO;
  	status = acpi_evaluate_object(drive->acpidata->obj_handle, "_GTF",
  				      NULL, &output);
  	if (ACPI_FAILURE(status)) {
  		printk(KERN_DEBUG
  		       "%s: Run _GTF error: status = 0x%x
  ",

  		       __func__, status);

  		goto out;
  	}
  
  	if (!output.length || !output.pointer) {
  		DEBPRINT("Run _GTF: "
  		       "length or ptr is NULL (0x%llx, 0x%p)
  ",
  		       (unsigned long long)output.length,
  		       output.pointer);
  		goto out;
  	}
  
  	out_obj = output.pointer;
  	if (out_obj->type != ACPI_TYPE_BUFFER) {
  		DEBPRINT("Run _GTF: error: "
  		       "expected object type of ACPI_TYPE_BUFFER, "
  		       "got 0x%x
  ", out_obj->type);
  		err = -ENOENT;
  		kfree(output.pointer);
  		goto out;
  	}
  
  	if (!out_obj->buffer.length || !out_obj->buffer.pointer ||
  	    out_obj->buffer.length % REGS_PER_GTF) {
  		printk(KERN_ERR
  		       "%s: unexpected GTF length (%d) or addr (0x%p)
  ",

  		       __func__, out_obj->buffer.length,

  		       out_obj->buffer.pointer);
  		err = -ENOENT;
  		kfree(output.pointer);
  		goto out;
  	}
  
  	*gtf_length = out_obj->buffer.length;
  	*gtf_address = (unsigned long)out_obj->buffer.pointer;
  	*obj_loc = (unsigned long)out_obj;
  	DEBPRINT("returning gtf_length=%d, gtf_address=0x%lx, obj_loc=0x%lx
  ",
  		 *gtf_length, *gtf_address, *obj_loc);
  	err = 0;
  out:
  	return err;
  }
  
  /**

   * do_drive_set_taskfiles - write the drive taskfile settings from _GTF
   * @drive: the drive to which the taskfile command should be sent
   * @gtf_length: total number of bytes of _GTF taskfiles
   * @gtf_address: location of _GTF taskfile arrays
   *
   * Write {gtf_address, length gtf_length} in groups of
   * REGS_PER_GTF bytes.
   */
  static int do_drive_set_taskfiles(ide_drive_t *drive,
  				  unsigned int gtf_length,
  				  unsigned long gtf_address)
  {

  	int			rc = 0, err;

  	int			gtf_count = gtf_length / REGS_PER_GTF;
  	int			ix;

  	DEBPRINT("total GTF bytes=%u (0x%x), gtf_count=%d, addr=0x%lx
  ",
  		 gtf_length, gtf_length, gtf_count, gtf_address);

  	/* send all taskfile registers (0x1f1-0x1f7) *in*that*order* */

  	for (ix = 0; ix < gtf_count; ix++) {

  		u8 *gtf = (u8 *)(gtf_address + ix * REGS_PER_GTF);

  		struct ide_cmd cmd;

  
  		DEBPRINT("(0x1f1-1f7): "
  			 "hex: %02x %02x %02x %02x %02x %02x %02x
  ",
  			 gtf[0], gtf[1], gtf[2],
  			 gtf[3], gtf[4], gtf[5], gtf[6]);
  
  		if (!ide_acpigtf) {
  			DEBPRINT("_GTF execution disabled
  ");
  			continue;
  		}
  
  		/* convert GTF to taskfile */

  		memset(&cmd, 0, sizeof(cmd));

  		memcpy(&cmd.tf.feature, gtf, REGS_PER_GTF);

  		cmd.valid.out.tf = IDE_VALID_OUT_TF | IDE_VALID_DEVICE;
  		cmd.valid.in.tf  = IDE_VALID_IN_TF  | IDE_VALID_DEVICE;

  		err = ide_no_data_taskfile(drive, &cmd);

  		if (err) {
  			printk(KERN_ERR "%s: ide_no_data_taskfile failed: %u
  ",
  					__func__, err);

  			rc = err;

  		}

  	}

  	return rc;
  }
  
  /**
   * ide_acpi_exec_tfs - get then write drive taskfile settings
   * @drive: the drive for which the taskfile settings should be
   *         written.
   *
   * According to the ACPI spec this should be called after _STM
   * has been evaluated for the interface. Some ACPI vendors interpret
   * that as a hard requirement and modify the taskfile according
   * to the Identify Drive information passed down with _STM.
   * So one should really make sure to call this only after _STM has
   * been executed.
   */
  int ide_acpi_exec_tfs(ide_drive_t *drive)
  {
  	int		ret;
  	unsigned int	gtf_length;
  	unsigned long	gtf_address;
  	unsigned long	obj_loc;

  	DEBPRINT("call get_GTF, drive=%s port=%d
  ", drive->name, drive->dn);
  
  	ret = do_drive_get_GTF(drive, &gtf_length, &gtf_address, &obj_loc);
  	if (ret < 0) {
  		DEBPRINT("get_GTF error (%d)
  ", ret);
  		return ret;
  	}
  
  	DEBPRINT("call set_taskfiles, drive=%s
  ", drive->name);
  
  	ret = do_drive_set_taskfiles(drive, gtf_length, gtf_address);
  	kfree((void *)obj_loc);
  	if (ret < 0) {
  		DEBPRINT("set_taskfiles error (%d)
  ", ret);
  	}
  
  	DEBPRINT("ret=%d
  ", ret);
  
  	return ret;
  }

  
  /**
   * ide_acpi_get_timing - get the channel (controller) timings
   * @hwif: target IDE interface (channel)
   *
   * This function executes the _GTM ACPI method for the target channel.
   *
   */
  void ide_acpi_get_timing(ide_hwif_t *hwif)
  {
  	acpi_status		status;
  	struct acpi_buffer	output;
  	union acpi_object 	*out_obj;

  	/* Setting up output buffer for _GTM */
  	output.length = ACPI_ALLOCATE_BUFFER;
  	output.pointer = NULL;	/* ACPI-CA sets this; save/free it later */
  
  	/* _GTM has no input parameters */
  	status = acpi_evaluate_object(hwif->acpidata->obj_handle, "_GTM",
  				      NULL, &output);
  
  	DEBPRINT("_GTM status: %d, outptr: 0x%p, outlen: 0x%llx
  ",
  		 status, output.pointer,
  		 (unsigned long long)output.length);
  
  	if (ACPI_FAILURE(status)) {
  		DEBPRINT("Run _GTM error: status = 0x%x
  ", status);
  		return;
  	}
  
  	if (!output.length || !output.pointer) {
  		DEBPRINT("Run _GTM: length or ptr is NULL (0x%llx, 0x%p)
  ",
  		       (unsigned long long)output.length,
  		       output.pointer);
  		kfree(output.pointer);
  		return;
  	}
  
  	out_obj = output.pointer;
  	if (out_obj->type != ACPI_TYPE_BUFFER) {

  		DEBPRINT("Run _GTM: error: "
  		       "expected object type of ACPI_TYPE_BUFFER, "
  		       "got 0x%x
  ", out_obj->type);

  		kfree(output.pointer);

  		return;
  	}
  
  	if (!out_obj->buffer.length || !out_obj->buffer.pointer ||
  	    out_obj->buffer.length != sizeof(struct GTM_buffer)) {

  		printk(KERN_ERR

  			"%s: unexpected _GTM length (0x%x)[should be 0x%zx] or "
  			"addr (0x%p)
  ",

  			__func__, out_obj->buffer.length,

  			sizeof(struct GTM_buffer), out_obj->buffer.pointer);

  		kfree(output.pointer);

  		return;
  	}
  
  	memcpy(&hwif->acpidata->gtm, out_obj->buffer.pointer,
  	       sizeof(struct GTM_buffer));
  
  	DEBPRINT("_GTM info: ptr: 0x%p, len: 0x%x, exp.len: 0x%Zx
  ",
  		 out_obj->buffer.pointer, out_obj->buffer.length,
  		 sizeof(struct GTM_buffer));
  
  	DEBPRINT("_GTM fields: 0x%x, 0x%x, 0x%x, 0x%x, 0x%x
  ",
  		 hwif->acpidata->gtm.PIO_speed0,
  		 hwif->acpidata->gtm.DMA_speed0,
  		 hwif->acpidata->gtm.PIO_speed1,
  		 hwif->acpidata->gtm.DMA_speed1,
  		 hwif->acpidata->gtm.GTM_flags);
  
  	kfree(output.pointer);
  }

  
  /**
   * ide_acpi_push_timing - set the channel (controller) timings
   * @hwif: target IDE interface (channel)
   *
   * This function executes the _STM ACPI method for the target channel.
   *
   * _STM requires Identify Drive data, which has to passed as an argument.

   * Unfortunately drive->id is a mangled version which we can't readily

   * use; hence we'll get the information afresh.
   */
  void ide_acpi_push_timing(ide_hwif_t *hwif)
  {
  	acpi_status		status;
  	struct acpi_object_list	input;
  	union acpi_object 	in_params[3];
  	struct ide_acpi_drive_link	*master = &hwif->acpidata->master;
  	struct ide_acpi_drive_link	*slave = &hwif->acpidata->slave;

  	/* Give the GTM buffer + drive Identify data to the channel via the
  	 * _STM method: */
  	/* setup input parameters buffer for _STM */
  	input.count = 3;
  	input.pointer = in_params;
  	in_params[0].type = ACPI_TYPE_BUFFER;
  	in_params[0].buffer.length = sizeof(struct GTM_buffer);
  	in_params[0].buffer.pointer = (u8 *)&hwif->acpidata->gtm;
  	in_params[1].type = ACPI_TYPE_BUFFER;

  	in_params[1].buffer.length = ATA_ID_WORDS * 2;

  	in_params[1].buffer.pointer = (u8 *)&master->idbuff;
  	in_params[2].type = ACPI_TYPE_BUFFER;

  	in_params[2].buffer.length = ATA_ID_WORDS * 2;

  	in_params[2].buffer.pointer = (u8 *)&slave->idbuff;
  	/* Output buffer: _STM has no output */
  
  	status = acpi_evaluate_object(hwif->acpidata->obj_handle, "_STM",
  				      &input, NULL);
  
  	if (ACPI_FAILURE(status)) {
  		DEBPRINT("Run _STM error: status = 0x%x
  ", status);
  	}
  	DEBPRINT("_STM status: %d
  ", status);
  }

  
  /**

   * ide_acpi_set_state - set the channel power state
   * @hwif: target IDE interface
   * @on: state, on/off
   *
   * This function executes the _PS0/_PS3 ACPI method to set the power state.
   * ACPI spec requires _PS0 when IDE power on and _PS3 when power off
   */
  void ide_acpi_set_state(ide_hwif_t *hwif, int on)
  {

  	ide_drive_t *drive;
  	int i;

  	if (ide_noacpi_psx)

  		return;
  
  	DEBPRINT("ENTER:
  ");

  	/* channel first and then drives for power on and verse versa for power off */
  	if (on)
  		acpi_bus_set_power(hwif->acpidata->obj_handle, ACPI_STATE_D0);

  	ide_port_for_each_present_dev(i, drive, hwif) {
  		if (drive->acpidata->obj_handle)

  			acpi_bus_set_power(drive->acpidata->obj_handle,

  					   on ? ACPI_STATE_D0 : ACPI_STATE_D3);

  	}

  	if (!on)
  		acpi_bus_set_power(hwif->acpidata->obj_handle, ACPI_STATE_D3);
  }

  
  /**

   * ide_acpi_init_port - initialize the ACPI link for an IDE interface

   * @hwif: target IDE interface (channel)
   *
   * The ACPI spec is not quite clear when the drive identify buffer
   * should be obtained. Calling IDENTIFY DEVICE during shutdown
   * is not the best of ideas as the drive might already being put to
   * sleep. And obviously we can't call it during resume.
   * So we get the information during startup; but this means that
   * any changes during run-time will be lost after resume.
   */

  void ide_acpi_init_port(ide_hwif_t *hwif)

  {

  	hwif->acpidata = kzalloc(sizeof(struct ide_acpi_hwif_link), GFP_KERNEL);
  	if (!hwif->acpidata)
  		return;
  
  	hwif->acpidata->obj_handle = ide_acpi_hwif_get_handle(hwif);
  	if (!hwif->acpidata->obj_handle) {
  		DEBPRINT("no ACPI object for %s found
  ", hwif->name);
  		kfree(hwif->acpidata);
  		hwif->acpidata = NULL;

  	}

  }
  
  void ide_acpi_port_init_devices(ide_hwif_t *hwif)
  {
  	ide_drive_t *drive;
  	int i, err;
  
  	if (hwif->acpidata == NULL)
  		return;

  
  	/*
  	 * The ACPI spec mandates that we send information
  	 * for both drives, regardless whether they are connected
  	 * or not.
  	 */

  	hwif->devices[0]->acpidata = &hwif->acpidata->master;
  	hwif->devices[1]->acpidata = &hwif->acpidata->slave;

  	/* get _ADR info for each device */

  	ide_port_for_each_present_dev(i, drive, hwif) {

  		acpi_handle dev_handle;

  		DEBPRINT("ENTER: %s at channel#: %d port#: %d
  ",
  			 drive->name, hwif->channel, drive->dn & 1);
  
  		/* TBD: could also check ACPI object VALID bits */
  		dev_handle = acpi_get_child(hwif->acpidata->obj_handle,
  					    drive->dn & 1);
  
  		DEBPRINT("drive %s handle 0x%p
  ", drive->name, dev_handle);
  
  		drive->acpidata->obj_handle = dev_handle;
  	}

  	/* send IDENTIFY for each device */
  	ide_port_for_each_present_dev(i, drive, hwif) {

  		err = taskfile_lib_get_identify(drive, drive->acpidata->idbuff);
  		if (err)

  			DEBPRINT("identify device %s failed (%d)
  ",

  				 drive->name, err);

  	}

  	if (ide_noacpi || ide_acpionboot == 0) {

  		DEBPRINT("ACPI methods disabled on boot
  ");
  		return;
  	}

  	/* ACPI _PS0 before _STM */
  	ide_acpi_set_state(hwif, 1);

  	/*
  	 * ACPI requires us to call _STM on startup
  	 */
  	ide_acpi_get_timing(hwif);
  	ide_acpi_push_timing(hwif);

  	ide_port_for_each_present_dev(i, drive, hwif) {
  		ide_acpi_exec_tfs(drive);

  	}
  }