diff options
Diffstat (limited to 'private/ntos/ndis/madge/driver/sys_dma.c')
| -rw-r--r-- | private/ntos/ndis/madge/driver/sys_dma.c | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/private/ntos/ndis/madge/driver/sys_dma.c b/private/ntos/ndis/madge/driver/sys_dma.c new file mode 100644 index 000000000..42d5b5244 --- /dev/null +++ b/private/ntos/ndis/madge/driver/sys_dma.c @@ -0,0 +1,233 @@ +/**************************************************************************** +* +* SYS_DMA.C +* +* This module contains helper routines used by the FTK to initialise +* DMA access to adapters. +* +* Copyright (c) Madge Networks Ltd 1991-1994 +* +* COMPANY CONFIDENTIAL +* +* Created: MF +* Major modifications: PBA 21/06/1994 +* +****************************************************************************/ + +#include <ndis.h> + +#include "ftk_defs.h" +#include "ftk_extr.h" + +#include "ndismod.h" + +/*--------------------------------------------------------------------------- +| +| DMA General Note +| ---------------- +| +| On an IBM compatible PC/AT machine, DMA is controlled by Programmable +| DMA Controller 8237 chips. On AT machines there are two 8237 DMA +| controllers. The primary controller handles DMA channels 0-3, the +| secondary controller handles channels 4-7. +| +| The FTK is interested in three registers on each controller. These are +| the mode register for setting the DMA mode for a given channel, the +| mask register used for enabling/disabling a DMA channel, and the status +| register for seeing what DMA channel requests have been generated. +| +---------------------------------------------------------------------------*/ + +// +// IO ports for status, mask and mode registers on primary DMA controller +// + +#define DMA_STATUS_PRIMARY_8237 0x08 +#define DMA_MASK_PRIMARY_8237 0x0A +#define DMA_MODE_PRIMARY_8237 0x0B + +// +// IO ports for status, mask and mode registers on secondary DMA controller +// + +#define DMA_STATUS_SECONDARY_8237 0x0D0 +#define DMA_MASK_SECONDARY_8237 0x0D4 +#define DMA_MODE_SECONDARY_8237 0x0D6 + +// +// Set cascade mode code (sent to mode register along with DMA channel) +// + +#define DMA_CASCADE_MODE_8237 0x0C0 + +// +// Disable DMA channel code (sent to mask register along with DMA channel) +// + +#define DMA_DISABLE_MASK_8237 0x04 + + +/**************************************************************************** +* +* Function - sys_enable_dma_channel +* +* Parameters - adapter_handle -> FTK adapter handle. +* dma_channel -> The DMA channel number. +* +* Purpose - Initialise a DMA channel. +* +* Returns - TRUE on success or FALSE on failure. +* +* Notes: +* +* With the NDIS3 driver the dma channel is enabled by the underlying +* operating system. We pass information about our adapter in the +* NDIS_ADAPTER_INFORMATION structure, including whether its a +* BusMasterDma card --- by setting the AdapterInformation.Master flag +* in MDGNT.c. +* +* So eventually this routine should be null and just return TRUE. +* +* Upto NT build 438, there is a problem with the AdapterInformation.Master +* flag. Setting it does not enable the DMA channel on certain ISA/AT +* platforms. Therefore the following code has been included such that we +* explicitly enable the DMA channel. +* +* The DMA channel has been specified in the AdapterInformation structure +* passed by the MAC driver to NdisRegisterAdapter() +* +****************************************************************************/ + +WBOOLEAN +sys_enable_dma_channel(ADAPTER_HANDLE adapter_handle, WORD dma_channel); + +#pragma FTK_INIT_FUNCTION(sys_enable_dma_channel) + +WBOOLEAN +sys_enable_dma_channel(ADAPTER_HANDLE adapter_handle, WORD dma_channel) +{ +#ifdef _M_IX86 + + if (dma_channel < 4) + { + // + // Program up primary 8237. Write local DMA channel with cascade + // mode to mode register. Write local DMA channel to mask register + // to enable it. + // + + // + // (dma_channel + DMA_CASCADE_MODE_8237) -> DMA_MODE_PRIMARY_8237 + // + + sys_outsb( + adapter_handle, + (WORD) DMA_MODE_PRIMARY_8237, + (BYTE) (dma_channel + DMA_CASCADE_MODE_8237) + ); + + // + // (dma_channel) -> DMA_MASK_PRIMARY_8237 + // + + sys_outsb( + adapter_handle, + (WORD) DMA_MASK_PRIMARY_8237, + (BYTE) dma_channel + ); + + } + else + { + // + // Program up secondary 8237. Get local DMA channel by DMA-4. + // Write local DMA channel with cascade mode to mode register. + // Write local DMA channel to mask register to enable it. + // + + dma_channel = dma_channel - 4; + + // + // (dma_channel + DMA_CASCADE_MODE_8237) -> DMA_MODE_SECONDARY_8237 + // + + sys_outsb( + adapter_handle, + (WORD) DMA_MODE_SECONDARY_8237, + (BYTE)(dma_channel + DMA_CASCADE_MODE_8237) + ); + + + // + // (dma_channel) -> DMA_MASK_SECONDARY_8237 + // + + sys_outsb( + adapter_handle, + (WORD) DMA_MASK_SECONDARY_8237, + (BYTE) dma_channel + ); + } + +#endif + + return TRUE; +} + + +/**************************************************************************** +* +* Function - sys_disable_dma_channel +* +* Parameters - adapter_handle -> FTK adapter handle. +* dma_channel -> The DMA channel number. +* +* Purpose - De-initialise a DMA channel. +* +* Returns - Nothing. +* +* Notes: +* +* Upto NT build 438, there is a problem with the AdapterInformation.Master +* flag. Setting it does not enable the DMA channel on certain ISA/AT +* platforms. Therefore the code in sys_enable_dma_channel() above, has been +* included such that we explicitly enable the DMA channel. +* +* Eventually, the Operating system will do this for us. And will also disable +* the DMA channel when the driver is unloaded. +* +* Therefore, I have not added code to explicitly disable DMA channel. +* +* +* However, if we do not disable the channel certain ISA platforms hang +* on shutdown. (pba 25/5/1994) +* +***************************************************************************/ + +void +sys_disable_dma_channel(ADAPTER_HANDLE adapter_handle, WORD dma_channel) +{ +#ifdef _M_IX86 + + if (dma_channel < 4) + { + sys_outsb( + adapter_handle, + (WORD) DMA_MASK_PRIMARY_8237, + (BYTE) (DMA_DISABLE_MASK_8237 + dma_channel) + ); + } + else + { + sys_outsb( + adapter_handle, + (WORD)DMA_MASK_SECONDARY_8237, + (BYTE)(DMA_DISABLE_MASK_8237 + (dma_channel - 4)) + ); + } + +#endif +} + + +/******** End of SYS_DMA.C *************************************************/ |