diff options
author | Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> | 2011-10-13 13:39:10 (GMT) |
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committer | Jeff Garzik <jgarzik@redhat.com> | 2011-10-14 17:37:36 (GMT) |
commit | 6a94a746fb2572c03c664acece101ee03dae7a17 (patch) | |
tree | 08362472bd03ce67d30955cb4caa5310ab9f31b7 /drivers/ata/ata_piix.c | |
parent | ce986690d9bfabb8c61fd8fe785fce5d95210b66 (diff) | |
download | linux-fsl-qoriq-6a94a746fb2572c03c664acece101ee03dae7a17.tar.xz |
ata_piix: unify code for programming PIO and MWDMA timings
Besides making things noticably simpler it results in ~2% decrease in
the driver LOC count and also ~2% decrease in the driver binary size
(as measured on x86-32).
Fix piix_set_piomode() documentation while at it.
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Diffstat (limited to 'drivers/ata/ata_piix.c')
-rw-r--r-- | drivers/ata/ata_piix.c | 111 |
1 files changed, 38 insertions, 73 deletions
diff --git a/drivers/ata/ata_piix.c b/drivers/ata/ata_piix.c index 75fdd02..69ac373 100644 --- a/drivers/ata/ata_piix.c +++ b/drivers/ata/ata_piix.c @@ -731,22 +731,11 @@ static int piix_pata_prereset(struct ata_link *link, unsigned long deadline) static DEFINE_SPINLOCK(piix_lock); -/** - * piix_set_piomode - Initialize host controller PATA PIO timings - * @ap: Port whose timings we are configuring - * @adev: um - * - * Set PIO mode for device, in host controller PCI config space. - * - * LOCKING: - * None (inherited from caller). - */ - -static void piix_set_piomode(struct ata_port *ap, struct ata_device *adev) +static void piix_set_timings(struct ata_port *ap, struct ata_device *adev, + u8 pio) { struct pci_dev *dev = to_pci_dev(ap->host->dev); unsigned long flags; - unsigned int pio = adev->pio_mode - XFER_PIO_0; unsigned int is_slave = (adev->devno != 0); unsigned int master_port= ap->port_no ? 0x42 : 0x40; unsigned int slave_port = 0x44; @@ -771,10 +760,16 @@ static void piix_set_piomode(struct ata_port *ap, struct ata_device *adev) control |= 1; /* TIME1 enable */ if (ata_pio_need_iordy(adev)) control |= 2; /* IE enable */ - /* Intel specifies that the PPE functionality is for disk only */ if (adev->class == ATA_DEV_ATA) control |= 4; /* PPE enable */ + /* + * If the drive MWDMA is faster than it can do PIO then + * we must force PIO into PIO0 + */ + if (adev->pio_mode < XFER_PIO_0 + pio) + /* Enable DMA timing only */ + control |= 8; /* PIO cycles in PIO0 */ spin_lock_irqsave(&piix_lock, flags); @@ -823,6 +818,22 @@ static void piix_set_piomode(struct ata_port *ap, struct ata_device *adev) } /** + * piix_set_piomode - Initialize host controller PATA PIO timings + * @ap: Port whose timings we are configuring + * @adev: Drive in question + * + * Set PIO mode for device, in host controller PCI config space. + * + * LOCKING: + * None (inherited from caller). + */ + +static void piix_set_piomode(struct ata_port *ap, struct ata_device *adev) +{ + piix_set_timings(ap, adev, adev->pio_mode - XFER_PIO_0); +} + +/** * do_pata_set_dmamode - Initialize host controller PATA PIO timings * @ap: Port whose timings we are configuring * @adev: Drive in question @@ -838,31 +849,20 @@ static void do_pata_set_dmamode(struct ata_port *ap, struct ata_device *adev, in { struct pci_dev *dev = to_pci_dev(ap->host->dev); unsigned long flags; - u8 master_port = ap->port_no ? 0x42 : 0x40; - u16 master_data; u8 speed = adev->dma_mode; int devid = adev->devno + 2 * ap->port_no; u8 udma_enable = 0; - static const /* ISP RTC */ - u8 timings[][2] = { { 0, 0 }, - { 0, 0 }, - { 1, 0 }, - { 2, 1 }, - { 2, 3 }, }; - - spin_lock_irqsave(&piix_lock, flags); - - pci_read_config_word(dev, master_port, &master_data); - if (ap->udma_mask) - pci_read_config_byte(dev, 0x48, &udma_enable); - if (speed >= XFER_UDMA_0) { - unsigned int udma = adev->dma_mode - XFER_UDMA_0; + unsigned int udma = speed - XFER_UDMA_0; u16 udma_timing; u16 ideconf; int u_clock, u_speed; + spin_lock_irqsave(&piix_lock, flags); + + pci_read_config_byte(dev, 0x48, &udma_enable); + /* * UDMA is handled by a combination of clock switching and * selection of dividers @@ -895,56 +895,21 @@ static void do_pata_set_dmamode(struct ata_port *ap, struct ata_device *adev, in performance (WR_PingPong_En) */ pci_write_config_word(dev, 0x54, ideconf); } + + pci_write_config_byte(dev, 0x48, udma_enable); + + spin_unlock_irqrestore(&piix_lock, flags); } else { - /* - * MWDMA is driven by the PIO timings. We must also enable - * IORDY unconditionally along with TIME1. PPE has already - * been set when the PIO timing was set. - */ - unsigned int mwdma = adev->dma_mode - XFER_MW_DMA_0; - unsigned int control; - u8 slave_data; + /* MWDMA is driven by the PIO timings. */ + unsigned int mwdma = speed - XFER_MW_DMA_0; const unsigned int needed_pio[3] = { XFER_PIO_0, XFER_PIO_3, XFER_PIO_4 }; int pio = needed_pio[mwdma] - XFER_PIO_0; - control = 3; /* IORDY|TIME1 */ - - /* If the drive MWDMA is faster than it can do PIO then - we must force PIO into PIO0 */ - - if (adev->pio_mode < needed_pio[mwdma]) - /* Enable DMA timing only */ - control |= 8; /* PIO cycles in PIO0 */ - - if (adev->devno) { /* Slave */ - master_data &= 0xFF4F; /* Mask out IORDY|TIME1|DMAONLY */ - master_data |= control << 4; - pci_read_config_byte(dev, 0x44, &slave_data); - slave_data &= (ap->port_no ? 0x0f : 0xf0); - /* Load the matching timing */ - slave_data |= ((timings[pio][0] << 2) | timings[pio][1]) << (ap->port_no ? 4 : 0); - pci_write_config_byte(dev, 0x44, slave_data); - } else { /* Master */ - master_data &= 0xCCF4; /* Mask out IORDY|TIME1|DMAONLY - and master timing bits */ - master_data |= control; - master_data |= - (timings[pio][0] << 12) | - (timings[pio][1] << 8); - } - - if (ap->udma_mask) - udma_enable &= ~(1 << devid); - - pci_write_config_word(dev, master_port, master_data); + /* XFER_PIO_0 is never used currently */ + piix_set_timings(ap, adev, pio); } - /* Don't scribble on 0x48 if the controller does not support UDMA */ - if (ap->udma_mask) - pci_write_config_byte(dev, 0x48, udma_enable); - - spin_unlock_irqrestore(&piix_lock, flags); } /** |