aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/scsi/libata-core.c
diff options
context:
space:
mode:
authorEdward Falk <efalk@google.com>2005-06-02 18:17:13 -0400
committerJeff Garzik <jgarzik@pobox.com>2005-06-02 18:17:13 -0400
commit0baab86b00cdf9785ac2bb2ce1ab63995b3866ca (patch)
tree9a92597d6e1653a9a9b3ed7f371d62237e68a6e9 /drivers/scsi/libata-core.c
parent92bab26be5544d8b495389646490fcfdca6dbcf2 (diff)
libata: update inline source docs
Diffstat (limited to 'drivers/scsi/libata-core.c')
-rw-r--r--drivers/scsi/libata-core.c283
1 files changed, 276 insertions, 7 deletions
diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index 31b2984f379a..86e84ed87bee 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -186,6 +186,28 @@ static void ata_tf_load_mmio(struct ata_port *ap, struct ata_taskfile *tf)
ata_wait_idle(ap);
}
+
+/**
+ * ata_tf_load - send taskfile registers to host controller
+ * @ap: Port to which output is sent
+ * @tf: ATA taskfile register set
+ *
+ * Outputs ATA taskfile to standard ATA host controller using MMIO
+ * or PIO as indicated by the ATA_FLAG_MMIO flag.
+ * Writes the control, feature, nsect, lbal, lbam, and lbah registers.
+ * Optionally (ATA_TFLAG_LBA48) writes hob_feature, hob_nsect,
+ * hob_lbal, hob_lbam, and hob_lbah.
+ *
+ * This function waits for idle (!BUSY and !DRQ) after writing
+ * registers. If the control register has a new value, this
+ * function also waits for idle after writing control and before
+ * writing the remaining registers.
+ *
+ * May be used as the tf_load() entry in ata_port_operations.
+ *
+ * LOCKING:
+ * Inherited from caller.
+ */
void ata_tf_load(struct ata_port *ap, struct ata_taskfile *tf)
{
if (ap->flags & ATA_FLAG_MMIO)
@@ -195,11 +217,11 @@ void ata_tf_load(struct ata_port *ap, struct ata_taskfile *tf)
}
/**
- * ata_exec_command - issue ATA command to host controller
+ * ata_exec_command_pio - issue ATA command to host controller
* @ap: port to which command is being issued
* @tf: ATA taskfile register set
*
- * Issues PIO/MMIO write to ATA command register, with proper
+ * Issues PIO write to ATA command register, with proper
* synchronization with interrupt handler / other threads.
*
* LOCKING:
@@ -235,6 +257,18 @@ static void ata_exec_command_mmio(struct ata_port *ap, struct ata_taskfile *tf)
ata_pause(ap);
}
+
+/**
+ * ata_exec_command - issue ATA command to host controller
+ * @ap: port to which command is being issued
+ * @tf: ATA taskfile register set
+ *
+ * Issues PIO/MMIO write to ATA command register, with proper
+ * synchronization with interrupt handler / other threads.
+ *
+ * LOCKING:
+ * spin_lock_irqsave(host_set lock)
+ */
void ata_exec_command(struct ata_port *ap, struct ata_taskfile *tf)
{
if (ap->flags & ATA_FLAG_MMIO)
@@ -305,7 +339,7 @@ void ata_tf_to_host_nolock(struct ata_port *ap, struct ata_taskfile *tf)
}
/**
- * ata_tf_read - input device's ATA taskfile shadow registers
+ * ata_tf_read_pio - input device's ATA taskfile shadow registers
* @ap: Port from which input is read
* @tf: ATA taskfile register set for storing input
*
@@ -368,6 +402,23 @@ static void ata_tf_read_mmio(struct ata_port *ap, struct ata_taskfile *tf)
}
}
+
+/**
+ * ata_tf_read - input device's ATA taskfile shadow registers
+ * @ap: Port from which input is read
+ * @tf: ATA taskfile register set for storing input
+ *
+ * Reads ATA taskfile registers for currently-selected device
+ * into @tf.
+ *
+ * Reads nsect, lbal, lbam, lbah, and device. If ATA_TFLAG_LBA48
+ * is set, also reads the hob registers.
+ *
+ * May be used as the tf_read() entry in ata_port_operations.
+ *
+ * LOCKING:
+ * Inherited from caller.
+ */
void ata_tf_read(struct ata_port *ap, struct ata_taskfile *tf)
{
if (ap->flags & ATA_FLAG_MMIO)
@@ -381,7 +432,7 @@ void ata_tf_read(struct ata_port *ap, struct ata_taskfile *tf)
* @ap: port where the device is
*
* Reads ATA taskfile status register for currently-selected device
- * and return it's value. This also clears pending interrupts
+ * and return its value. This also clears pending interrupts
* from this device
*
* LOCKING:
@@ -397,7 +448,7 @@ static u8 ata_check_status_pio(struct ata_port *ap)
* @ap: port where the device is
*
* Reads ATA taskfile status register for currently-selected device
- * via MMIO and return it's value. This also clears pending interrupts
+ * via MMIO and return its value. This also clears pending interrupts
* from this device
*
* LOCKING:
@@ -408,6 +459,20 @@ static u8 ata_check_status_mmio(struct ata_port *ap)
return readb((void __iomem *) ap->ioaddr.status_addr);
}
+
+/**
+ * ata_check_status - Read device status reg & clear interrupt
+ * @ap: port where the device is
+ *
+ * Reads ATA taskfile status register for currently-selected device
+ * and return its value. This also clears pending interrupts
+ * from this device
+ *
+ * May be used as the check_status() entry in ata_port_operations.
+ *
+ * LOCKING:
+ * Inherited from caller.
+ */
u8 ata_check_status(struct ata_port *ap)
{
if (ap->flags & ATA_FLAG_MMIO)
@@ -415,6 +480,20 @@ u8 ata_check_status(struct ata_port *ap)
return ata_check_status_pio(ap);
}
+
+/**
+ * ata_altstatus - Read device alternate status reg
+ * @ap: port where the device is
+ *
+ * Reads ATA taskfile alternate status register for
+ * currently-selected device and return its value.
+ *
+ * Note: may NOT be used as the check_altstatus() entry in
+ * ata_port_operations.
+ *
+ * LOCKING:
+ * Inherited from caller.
+ */
u8 ata_altstatus(struct ata_port *ap)
{
if (ap->ops->check_altstatus)
@@ -425,6 +504,20 @@ u8 ata_altstatus(struct ata_port *ap)
return inb(ap->ioaddr.altstatus_addr);
}
+
+/**
+ * ata_chk_err - Read device error reg
+ * @ap: port where the device is
+ *
+ * Reads ATA taskfile error register for
+ * currently-selected device and return its value.
+ *
+ * Note: may NOT be used as the check_err() entry in
+ * ata_port_operations.
+ *
+ * LOCKING:
+ * Inherited from caller.
+ */
u8 ata_chk_err(struct ata_port *ap)
{
if (ap->ops->check_err)
@@ -873,10 +966,24 @@ void ata_dev_id_string(u16 *id, unsigned char *s,
}
}
+
+/**
+ * ata_noop_dev_select - Select device 0/1 on ATA bus
+ * @ap: ATA channel to manipulate
+ * @device: ATA device (numbered from zero) to select
+ *
+ * This function performs no actual function.
+ *
+ * May be used as the dev_select() entry in ata_port_operations.
+ *
+ * LOCKING:
+ * caller.
+ */
void ata_noop_dev_select (struct ata_port *ap, unsigned int device)
{
}
+
/**
* ata_std_dev_select - Select device 0/1 on ATA bus
* @ap: ATA channel to manipulate
@@ -884,7 +991,9 @@ void ata_noop_dev_select (struct ata_port *ap, unsigned int device)
*
* Use the method defined in the ATA specification to
* make either device 0, or device 1, active on the
- * ATA channel.
+ * ATA channel. Works with both PIO and MMIO.
+ *
+ * May be used as the dev_select() entry in ata_port_operations.
*
* LOCKING:
* caller.
@@ -2127,6 +2236,19 @@ void ata_qc_prep(struct ata_queued_cmd *qc)
* spin_lock_irqsave(host_set lock)
*/
+
+
+/**
+ * ata_sg_init_one - Prepare a one-entry scatter-gather list.
+ * @qc: Queued command
+ * @buf: transfer buffer
+ * @buflen: length of buf
+ *
+ * Builds a single-entry scatter-gather list to initiate a
+ * transfer utilizing the specified buffer.
+ *
+ * LOCKING:
+ */
void ata_sg_init_one(struct ata_queued_cmd *qc, void *buf, unsigned int buflen)
{
struct scatterlist *sg;
@@ -2158,6 +2280,18 @@ void ata_sg_init_one(struct ata_queued_cmd *qc, void *buf, unsigned int buflen)
* spin_lock_irqsave(host_set lock)
*/
+
+/**
+ * ata_sg_init - Assign a scatter gather list to a queued command
+ * @qc: Queued command
+ * @sg: Scatter-gather list
+ * @n_elem: length of sg list
+ *
+ * Attaches a scatter-gather list to a queued command.
+ *
+ * LOCKING:
+ */
+
void ata_sg_init(struct ata_queued_cmd *qc, struct scatterlist *sg,
unsigned int n_elem)
{
@@ -2331,6 +2465,18 @@ static void ata_pio_complete (struct ata_port *ap)
ata_qc_complete(qc, drv_stat);
}
+
+/**
+ * swap_buf_le16 -
+ * @buf: Buffer to swap
+ * @buf_words: Number of 16-bit words in buffer.
+ *
+ * Swap halves of 16-bit words if needed to convert from
+ * little-endian byte order to native cpu byte order, or
+ * vice-versa.
+ *
+ * LOCKING:
+ */
void swap_buf_le16(u16 *buf, unsigned int buf_words)
{
#ifdef __BIG_ENDIAN
@@ -2992,6 +3138,7 @@ err_out:
return -1;
}
+
/**
* ata_qc_issue_prot - issue taskfile to device in proto-dependent manner
* @qc: command to issue to device
@@ -3001,6 +3148,8 @@ err_out:
* classes called "protocols", and issuing each type of protocol
* is slightly different.
*
+ * May be used as the qc_issue() entry in ata_port_operations.
+ *
* LOCKING:
* spin_lock_irqsave(host_set lock)
*
@@ -3058,7 +3207,7 @@ int ata_qc_issue_prot(struct ata_queued_cmd *qc)
}
/**
- * ata_bmdma_setup - Set up PCI IDE BMDMA transaction
+ * ata_bmdma_setup_mmio - Set up PCI IDE BMDMA transaction
* @qc: Info associated with this ATA transaction.
*
* LOCKING:
@@ -3165,6 +3314,18 @@ static void ata_bmdma_start_pio (struct ata_queued_cmd *qc)
ap->ioaddr.bmdma_addr + ATA_DMA_CMD);
}
+
+/**
+ * ata_bmdma_start - Start a PCI IDE BMDMA transaction
+ * @qc: Info associated with this ATA transaction.
+ *
+ * Writes the ATA_DMA_START flag to the DMA command register.
+ *
+ * May be used as the bmdma_start() entry in ata_port_operations.
+ *
+ * LOCKING:
+ * spin_lock_irqsave(host_set lock)
+ */
void ata_bmdma_start(struct ata_queued_cmd *qc)
{
if (qc->ap->flags & ATA_FLAG_MMIO)
@@ -3173,6 +3334,20 @@ void ata_bmdma_start(struct ata_queued_cmd *qc)
ata_bmdma_start_pio(qc);
}
+
+/**
+ * ata_bmdma_setup - Set up PCI IDE BMDMA transaction
+ * @qc: Info associated with this ATA transaction.
+ *
+ * Writes address of PRD table to device's PRD Table Address
+ * register, sets the DMA control register, and calls
+ * ops->exec_command() to start the transfer.
+ *
+ * May be used as the bmdma_setup() entry in ata_port_operations.
+ *
+ * LOCKING:
+ * spin_lock_irqsave(host_set lock)
+ */
void ata_bmdma_setup(struct ata_queued_cmd *qc)
{
if (qc->ap->flags & ATA_FLAG_MMIO)
@@ -3181,6 +3356,19 @@ void ata_bmdma_setup(struct ata_queued_cmd *qc)
ata_bmdma_setup_pio(qc);
}
+
+/**
+ * ata_bmdma_irq_clear - Clear PCI IDE BMDMA interrupt.
+ * @qc: Info associated with this ATA transaction.
+ *
+ * Clear interrupt and error flags in DMA status register.
+ *
+ * May be used as the irq_clear() entry in ata_port_operations.
+ *
+ * LOCKING:
+ * spin_lock_irqsave(host_set lock)
+ */
+
void ata_bmdma_irq_clear(struct ata_port *ap)
{
if (ap->flags & ATA_FLAG_MMIO) {
@@ -3193,6 +3381,19 @@ void ata_bmdma_irq_clear(struct ata_port *ap)
}
+
+/**
+ * ata_bmdma_status - Read PCI IDE BMDMA status
+ * @qc: Info associated with this ATA transaction.
+ *
+ * Read and return BMDMA status register.
+ *
+ * May be used as the bmdma_status() entry in ata_port_operations.
+ *
+ * LOCKING:
+ * spin_lock_irqsave(host_set lock)
+ */
+
u8 ata_bmdma_status(struct ata_port *ap)
{
u8 host_stat;
@@ -3204,6 +3405,19 @@ u8 ata_bmdma_status(struct ata_port *ap)
return host_stat;
}
+
+/**
+ * ata_bmdma_stop - Stop PCI IDE BMDMA transfer
+ * @qc: Info associated with this ATA transaction.
+ *
+ * Clears the ATA_DMA_START flag in the dma control register
+ *
+ * May be used as the bmdma_stop() entry in ata_port_operations.
+ *
+ * LOCKING:
+ * spin_lock_irqsave(host_set lock)
+ */
+
void ata_bmdma_stop(struct ata_port *ap)
{
if (ap->flags & ATA_FLAG_MMIO) {
@@ -3407,6 +3621,19 @@ err_out:
ata_qc_complete(qc, ATA_ERR);
}
+
+/**
+ * ata_port_start - Set port up for dma.
+ * @ap: Port to initialize
+ *
+ * Called just after data structures for each port are
+ * initialized. Allocates space for PRD table.
+ *
+ * May be used as the port_start() entry in ata_port_operations.
+ *
+ * LOCKING:
+ */
+
int ata_port_start (struct ata_port *ap)
{
struct device *dev = ap->host_set->dev;
@@ -3420,6 +3647,18 @@ int ata_port_start (struct ata_port *ap)
return 0;
}
+
+/**
+ * ata_port_stop - Undo ata_port_start()
+ * @ap: Port to shut down
+ *
+ * Frees the PRD table.
+ *
+ * May be used as the port_stop() entry in ata_port_operations.
+ *
+ * LOCKING:
+ */
+
void ata_port_stop (struct ata_port *ap)
{
struct device *dev = ap->host_set->dev;
@@ -3720,7 +3959,15 @@ int ata_scsi_release(struct Scsi_Host *host)
/**
* ata_std_ports - initialize ioaddr with standard port offsets.
* @ioaddr: IO address structure to be initialized
+ *
+ * Utility function which initializes data_addr, error_addr,
+ * feature_addr, nsect_addr, lbal_addr, lbam_addr, lbah_addr,
+ * device_addr, status_addr, and command_addr to standard offsets
+ * relative to cmd_addr.
+ *
+ * Does not set ctl_addr, altstatus_addr, bmdma_addr, or scr_addr.
*/
+
void ata_std_ports(struct ata_ioports *ioaddr)
{
ioaddr->data_addr = ioaddr->cmd_addr + ATA_REG_DATA;
@@ -3762,6 +4009,20 @@ ata_probe_ent_alloc(struct device *dev, struct ata_port_info *port)
return probe_ent;
}
+
+
+/**
+ * ata_pci_init_native_mode - Initialize native-mode driver
+ * @pdev: pci device to be initialized
+ * @port: array[2] of pointers to port info structures.
+ *
+ * Utility function which allocates and initializes an
+ * ata_probe_ent structure for a standard dual-port
+ * PIO-based IDE controller. The returned ata_probe_ent
+ * structure can be passed to ata_device_add(). The returned
+ * ata_probe_ent structure should then be freed with kfree().
+ */
+
#ifdef CONFIG_PCI
struct ata_probe_ent *
ata_pci_init_native_mode(struct pci_dev *pdev, struct ata_port_info **port)
@@ -3843,6 +4104,14 @@ ata_pci_init_legacy_mode(struct pci_dev *pdev, struct ata_port_info **port,
* @port_info: Information from low-level host driver
* @n_ports: Number of ports attached to host controller
*
+ * This is a helper function which can be called from a driver's
+ * xxx_init_one() probe function if the hardware uses traditional
+ * IDE taskfile registers.
+ *
+ * This function calls pci_enable_device(), reserves its register
+ * regions, sets the dma mask, enables bus master mode, and calls
+ * ata_device_add()
+ *
* LOCKING:
* Inherited from PCI layer (may sleep).
*

Privacy Policy