From: Edward Falk Date: Thu, 2 Jun 2005 22:17:13 +0000 (-0400) Subject: libata: update inline source docs X-Git-Tag: v2.6.12-rc6~23^2~2 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=0baab86b00cdf9785ac2bb2ce1ab63995b3866ca;p=linux-2.6-omap-h63xx.git libata: update inline source docs --- diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c index 31b2984f379..86e84ed87be 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). * diff --git a/include/linux/libata.h b/include/linux/libata.h index 1f7e2039a04..ad410590664 100644 --- a/include/linux/libata.h +++ b/include/linux/libata.h @@ -466,12 +466,34 @@ static inline u8 ata_chk_status(struct ata_port *ap) return ap->ops->check_status(ap); } + +/** + * ata_pause - Flush writes and pause 400 nanoseconds. + * @ap: Port to wait for. + * + * LOCKING: + * Inherited from caller. + */ + static inline void ata_pause(struct ata_port *ap) { ata_altstatus(ap); ndelay(400); } + +/** + * ata_busy_wait - Wait for a port status register + * @ap: Port to wait for. + * + * Waits up to max*10 microseconds for the selected bits in the port's + * status register to be cleared. + * Returns final value of status register. + * + * LOCKING: + * Inherited from caller. + */ + static inline u8 ata_busy_wait(struct ata_port *ap, unsigned int bits, unsigned int max) { @@ -486,6 +508,18 @@ static inline u8 ata_busy_wait(struct ata_port *ap, unsigned int bits, return status; } + +/** + * ata_wait_idle - Wait for a port to be idle. + * @ap: Port to wait for. + * + * Waits up to 10ms for port's BUSY and DRQ signals to clear. + * Returns final value of status register. + * + * LOCKING: + * Inherited from caller. + */ + static inline u8 ata_wait_idle(struct ata_port *ap) { u8 status = ata_busy_wait(ap, ATA_BUSY | ATA_DRQ, 1000); @@ -524,6 +558,18 @@ static inline void ata_tf_init(struct ata_port *ap, struct ata_taskfile *tf, uns tf->device = ATA_DEVICE_OBS | ATA_DEV1; } + +/** + * ata_irq_on - Enable interrupts on a port. + * @ap: Port on which interrupts are enabled. + * + * Enable interrupts on a legacy IDE device using MMIO or PIO, + * wait for idle, clear any pending interrupts. + * + * LOCKING: + * Inherited from caller. + */ + static inline u8 ata_irq_on(struct ata_port *ap) { struct ata_ioports *ioaddr = &ap->ioaddr; @@ -543,6 +589,18 @@ static inline u8 ata_irq_on(struct ata_port *ap) return tmp; } + +/** + * ata_irq_ack - Acknowledge a device interrupt. + * @ap: Port on which interrupts are enabled. + * + * Wait up to 10 ms for legacy IDE device to become idle (BUSY + * or BUSY+DRQ clear). Obtain dma status and port status from + * device. Clear the interrupt. Return port status. + * + * LOCKING: + */ + static inline u8 ata_irq_ack(struct ata_port *ap, unsigned int chk_drq) { unsigned int bits = chk_drq ? ATA_BUSY | ATA_DRQ : ATA_BUSY;