Files
linux/include/linux/platform_data/dma-bcm2708.h
Florian Meier dc7ae378ff dmaengine: Add support for BCM2708
Add support for DMA controller of BCM2708 as used in the Raspberry Pi.
Currently it only supports cyclic DMA.

Signed-off-by: Florian Meier <florian.meier@koalo.de>

dmaengine: expand functionality by supporting scatter/gather transfers sdhci-bcm2708 and dma.c: fix for LITE channels

DMA: fix cyclic LITE length overflow bug

dmaengine: bcm2708: Remove chancnt affectations

Mirror bcm2835-dma.c commit 9eba5536a7:
chancnt is already filled by dma_async_device_register, which uses the channel
list to know how much channels there is.

Since it's already filled, we can safely remove it from the drivers' probe
function.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dmaengine: bcm2708: overwrite dreq only if it is not set

dreq is set when the DMA channel is fetched from Device Tree.
slave_id is set using dmaengine_slave_config().
Only overwrite dreq with slave_id if it is not set.

dreq/slave_id in the cyclic DMA case is not touched, because I don't
have hardware to test with.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dmaengine: bcm2708: do device registration in the board file

Don't register the device in the driver. Do it in the board file.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dmaengine: bcm2708: don't restrict DT support to ARCH_BCM2835

Both ARCH_BCM2835 and ARCH_BCM270x are built with OF now.
Add Device Tree support to the non ARCH_BCM2835 case.
Use the same driver name regardless of architecture.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

BCM270x_DT: add bcm2835-dma entry

Add Device Tree entry for bcm2835-dma.
The entry doesn't contain any resources since they are handled
by the arch/arm/mach-bcm270x/dma.c driver.
In non-DT mode, don't add the device in the board file.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

bcm2708-dmaengine: Add debug options

BCM270x: Add memory and irq resources to dmaengine device and DT

Prepare for merging of the legacy DMA API arch driver dma.c
with bcm2708-dmaengine by adding memory and irq resources both
to platform file device and Device Tree node.
Don't use BCM_DMAMAN_DRIVER_NAME so we don't have to include mach/dma.h

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dmaengine: bcm2708: Merge with arch dma.c driver and disable dma.c

Merge the legacy DMA API driver with bcm2708-dmaengine.
This is done so we can use bcm2708_fb on ARCH_BCM2835 (mailbox
driver is also needed).

Changes to the dma.c code:
- Use BIT() macro.
- Cutdown some comments to one line.
- Add mutex to vc_dmaman and use this, since the dev lock is locked
  during probing of the engine part.
- Add global g_dmaman variable since drvdata is used by the engine part.
- Restructure for readability:
  vc_dmaman_chan_alloc()
  vc_dmaman_chan_free()
  bcm_dma_chan_free()
- Restructure bcm_dma_chan_alloc() to simplify error handling.
- Use device irq resources instead of hardcoded bcm_dma_irqs table.
- Remove dev_dmaman_register() and code it directly.
- Remove dev_dmaman_deregister() and code it directly.
- Simplify bcm_dmaman_probe() using devm_* functions.
- Get dmachans from DT if available.
- Keep 'dma.dmachans' module argument name for backwards compatibility.

Make it available on ARCH_BCM2835 as well.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dmaengine: bcm2708: set residue_granularity field

bcm2708-dmaengine supports residue reporting at burst level
but didn't report this via the residue_granularity field.

Without this field set properly we get playback issues with I2S cards.

dmaengine: bcm2708-dmaengine: Fix memory leak when stopping a running transfer

bcm2708-dmaengine: Use more DMA channels (but not 12)

1) Only the bcm2708_fb drivers uses the legacy DMA API, and
it requires a BULK-capable channel, so all other types
(FAST, NORMAL and LITE) can be made available to the regular
DMA API.

2) DMA channels 11-14 share an interrupt. The driver can't
handle this, so don't use channels 12-14 (12 was used, probably
because it appears to have an interrupt, but in reality that
interrupt is for activity on ANY channel). This may explain
a lockup encountered when running out of DMA channels.

The combined effect of this patch is to leave 7 DMA channels
available + channel 0 for bcm2708_fb via the legacy API.

See: https://github.com/raspberrypi/linux/issues/1110
     https://github.com/raspberrypi/linux/issues/1108

dmaengine: bcm2708: Make legacy API available for bcm2835-dma

bcm2708_fb uses the legacy DMA API, so in order to start using
bcm2835-dma, bcm2835-dma has to support the legacy API. Make this
possible by exporting bcm_dmaman_probe() and bcm_dmaman_remove().

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dmaengine: bcm2708: Change DT compatible string

Both bcm2835-dma and bcm2708-dmaengine have the same compatible string.
So change compatible to "brcm,bcm2708-dma".

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

dmaengine: bcm2708: Remove driver but keep legacy API

Dropping non-DT support means we don't need this driver,
but we still need the legacy DMA API.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

bcm2708-dmaengine - Fix arm64 portability/build issues

dma-bcm2708: Fix module compilation of CONFIG_DMA_BCM2708

bcm2708-dmaengine.c defines functions like bcm_dma_start which are
defined as well in dma-bcm2708.h as inline versions when
CONFIG_DMA_BCM2708 is not defined. This works fine when
CONFIG_DMA_BCM2708 is built in, but when it is selected as module build
fails with redefinition errors because in the build system when
CONFIG_DMA_BCM2708 is selected as module, the macro becomes
CONFIG_DMA_BCM2708_MODULE.

This patch makes the header use CONFIG_DMA_BCM2708_MODULE too when
available.

Fixes https://github.com/raspberrypi/linux/issues/2056

Signed-off-by: Andrei Gherzan <andrei@gherzan.com>

bcm2708-dmaengine: Use platform_get_irq

The platform driver framework no longer creates IRQ resources for
platform devices because they are expected to use platform_get_irq.
This causes the bcm2808_fb acceleration to fail.

Fix the problem by calling platform_get_irq as intended.

See: https://github.com/raspberrypi/linux/issues/5131

Signed-off-by: Phil Elwell <phil@raspberrypi.com>
2025-11-24 14:07:35 +00:00

144 lines
4.1 KiB
C

/*
* Copyright (C) 2010 Broadcom
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef _PLAT_BCM2708_DMA_H
#define _PLAT_BCM2708_DMA_H
/* DMA CS Control and Status bits */
#define BCM2708_DMA_ACTIVE BIT(0)
#define BCM2708_DMA_INT BIT(2)
#define BCM2708_DMA_ISPAUSED BIT(4) /* Pause requested or not active */
#define BCM2708_DMA_ISHELD BIT(5) /* Is held by DREQ flow control */
#define BCM2708_DMA_ERR BIT(8)
#define BCM2708_DMA_ABORT BIT(30) /* stop current CB, go to next, WO */
#define BCM2708_DMA_RESET BIT(31) /* WO, self clearing */
/* DMA control block "info" field bits */
#define BCM2708_DMA_INT_EN BIT(0)
#define BCM2708_DMA_TDMODE BIT(1)
#define BCM2708_DMA_WAIT_RESP BIT(3)
#define BCM2708_DMA_D_INC BIT(4)
#define BCM2708_DMA_D_WIDTH BIT(5)
#define BCM2708_DMA_D_DREQ BIT(6)
#define BCM2708_DMA_S_INC BIT(8)
#define BCM2708_DMA_S_WIDTH BIT(9)
#define BCM2708_DMA_S_DREQ BIT(10)
#define BCM2708_DMA_BURST(x) (((x) & 0xf) << 12)
#define BCM2708_DMA_PER_MAP(x) ((x) << 16)
#define BCM2708_DMA_WAITS(x) (((x) & 0x1f) << 21)
#define BCM2708_DMA_DREQ_EMMC 11
#define BCM2708_DMA_DREQ_SDHOST 13
#define BCM2708_DMA_CS 0x00 /* Control and Status */
#define BCM2708_DMA_ADDR 0x04
/* the current control block appears in the following registers - read only */
#define BCM2708_DMA_INFO 0x08
#define BCM2708_DMA_SOURCE_AD 0x0c
#define BCM2708_DMA_DEST_AD 0x10
#define BCM2708_DMA_NEXTCB 0x1C
#define BCM2708_DMA_DEBUG 0x20
#define BCM2708_DMA4_CS (BCM2708_DMA_CHAN(4) + BCM2708_DMA_CS)
#define BCM2708_DMA4_ADDR (BCM2708_DMA_CHAN(4) + BCM2708_DMA_ADDR)
#define BCM2708_DMA_TDMODE_LEN(w, h) ((h) << 16 | (w))
/* When listing features we can ask for when allocating DMA channels give
those with higher priority smaller ordinal numbers */
#define BCM_DMA_FEATURE_FAST_ORD 0
#define BCM_DMA_FEATURE_BULK_ORD 1
#define BCM_DMA_FEATURE_NORMAL_ORD 2
#define BCM_DMA_FEATURE_LITE_ORD 3
#define BCM_DMA_FEATURE_FAST BIT(BCM_DMA_FEATURE_FAST_ORD)
#define BCM_DMA_FEATURE_BULK BIT(BCM_DMA_FEATURE_BULK_ORD)
#define BCM_DMA_FEATURE_NORMAL BIT(BCM_DMA_FEATURE_NORMAL_ORD)
#define BCM_DMA_FEATURE_LITE BIT(BCM_DMA_FEATURE_LITE_ORD)
#define BCM_DMA_FEATURE_COUNT 4
struct bcm2708_dma_cb {
u32 info;
u32 src;
u32 dst;
u32 length;
u32 stride;
u32 next;
u32 pad[2];
};
struct scatterlist;
struct platform_device;
#if defined(CONFIG_DMA_BCM2708) || defined(CONFIG_DMA_BCM2708_MODULE)
int bcm_sg_suitable_for_dma(struct scatterlist *sg_ptr, int sg_len);
void bcm_dma_start(void __iomem *dma_chan_base, dma_addr_t control_block);
void bcm_dma_wait_idle(void __iomem *dma_chan_base);
bool bcm_dma_is_busy(void __iomem *dma_chan_base);
int bcm_dma_abort(void __iomem *dma_chan_base);
/* return channel no or -ve error */
int bcm_dma_chan_alloc(unsigned preferred_feature_set,
void __iomem **out_dma_base, int *out_dma_irq);
int bcm_dma_chan_free(int channel);
int bcm_dmaman_probe(struct platform_device *pdev, void __iomem *base,
u32 chans_available);
int bcm_dmaman_remove(struct platform_device *pdev);
#else /* CONFIG_DMA_BCM2708 */
static inline int bcm_sg_suitable_for_dma(struct scatterlist *sg_ptr,
int sg_len)
{
return 0;
}
static inline void bcm_dma_start(void __iomem *dma_chan_base,
dma_addr_t control_block) { }
static inline void bcm_dma_wait_idle(void __iomem *dma_chan_base) { }
static inline bool bcm_dma_is_busy(void __iomem *dma_chan_base)
{
return false;
}
static inline int bcm_dma_abort(void __iomem *dma_chan_base)
{
return -EINVAL;
}
static inline int bcm_dma_chan_alloc(unsigned preferred_feature_set,
void __iomem **out_dma_base,
int *out_dma_irq)
{
return -EINVAL;
}
static inline int bcm_dma_chan_free(int channel)
{
return -EINVAL;
}
static inline int bcm_dmaman_probe(struct platform_device *pdev,
void __iomem *base, u32 chans_available)
{
return 0;
}
static inline int bcm_dmaman_remove(struct platform_device *pdev)
{
return 0;
}
#endif /* CONFIG_DMA_BCM2708 || CONFIG_DMA_BCM2708_MODULE */
#endif /* _PLAT_BCM2708_DMA_H */