From f70575805708cabdedea7498aaa3f710fde4d920 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Wed, 31 Jan 2024 03:29:01 +0000
Subject: [PATCH] add lvds1024*800
---
kernel/drivers/dma/bcm2835-dma.c | 85 +++++++++++++++++++++---------------------
1 files changed, 42 insertions(+), 43 deletions(-)
diff --git a/kernel/drivers/dma/bcm2835-dma.c b/kernel/drivers/dma/bcm2835-dma.c
index 9d782cc..630dfbb 100644
--- a/kernel/drivers/dma/bcm2835-dma.c
+++ b/kernel/drivers/dma/bcm2835-dma.c
@@ -1,8 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0+
/*
* BCM2835 DMA engine support
- *
- * This driver only supports cyclic DMA transfers
- * as needed for the I2S module.
*
* Author: Florian Meier <florian.meier@koalo.de>
* Copyright 2013
@@ -18,16 +16,6 @@
*
* MARVELL MMP Peripheral DMA Driver
* Copyright 2012 Marvell International Ltd.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
*/
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
@@ -49,11 +37,17 @@
#define BCM2835_DMA_MAX_DMA_CHAN_SUPPORTED 14
#define BCM2835_DMA_CHAN_NAME_SIZE 8
+/**
+ * struct bcm2835_dmadev - BCM2835 DMA controller
+ * @ddev: DMA device
+ * @base: base address of register map
+ * @zero_page: bus address of zero page (to detect transactions copying from
+ * zero page and avoid accessing memory if so)
+ */
struct bcm2835_dmadev {
struct dma_device ddev;
- spinlock_t lock;
void __iomem *base;
- struct device_dma_parameters dma_parms;
+ dma_addr_t zero_page;
};
struct bcm2835_dma_cb {
@@ -73,7 +67,6 @@
struct bcm2835_chan {
struct virt_dma_chan vc;
- struct list_head node;
struct dma_slave_config cfg;
unsigned int dreq;
@@ -321,8 +314,7 @@
return NULL;
/* allocate and setup the descriptor. */
- d = kzalloc(sizeof(*d) + frames * sizeof(struct bcm2835_cb_entry),
- gfp);
+ d = kzalloc(struct_size(d, cb_list, frames), gfp);
if (!d)
return NULL;
@@ -415,7 +407,7 @@
}
}
-static int bcm2835_dma_abort(struct bcm2835_chan *c)
+static void bcm2835_dma_abort(struct bcm2835_chan *c)
{
void __iomem *chan_base = c->chan_base;
long int timeout = 10000;
@@ -425,7 +417,7 @@
* (The ACTIVE flag in the CS register is not a reliable indicator.)
*/
if (!readl(chan_base + BCM2835_DMA_ADDR))
- return 0;
+ return;
/* Write 0 to the active bit - Pause the DMA */
writel(0, chan_base + BCM2835_DMA_CS);
@@ -441,7 +433,6 @@
"failed to complete outstanding writes\n");
writel(BCM2835_DMA_RESET, chan_base + BCM2835_DMA_CS);
- return 0;
}
static void bcm2835_dma_start_desc(struct bcm2835_chan *c)
@@ -513,8 +504,12 @@
dev_dbg(dev, "Allocating DMA channel %d\n", c->ch);
+ /*
+ * Control blocks are 256 bit in length and must start at a 256 bit
+ * (32 byte) aligned address (BCM2835 ARM Peripherals, sec. 4.2.1.1).
+ */
c->cb_pool = dma_pool_create(dev_name(dev), dev,
- sizeof(struct bcm2835_dma_cb), 0, 0);
+ sizeof(struct bcm2835_dma_cb), 32, 0);
if (!c->cb_pool) {
dev_err(dev, "unable to allocate descriptor pool\n");
return -ENOMEM;
@@ -683,7 +678,7 @@
d = bcm2835_dma_create_cb_chain(chan, direction, false,
info, extra,
frames, src, dst, 0, 0,
- GFP_KERNEL);
+ GFP_NOWAIT);
if (!d)
return NULL;
@@ -699,11 +694,12 @@
size_t period_len, enum dma_transfer_direction direction,
unsigned long flags)
{
+ struct bcm2835_dmadev *od = to_bcm2835_dma_dev(chan->device);
struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
struct bcm2835_desc *d;
dma_addr_t src, dst;
u32 info = BCM2835_DMA_WAIT_RESP;
- u32 extra = BCM2835_DMA_INT_EN;
+ u32 extra = 0;
size_t max_len = bcm2835_dma_max_frame_length(c);
size_t frames;
@@ -718,6 +714,11 @@
"%s: bad buffer length (= 0)\n", __func__);
return NULL;
}
+
+ if (flags & DMA_PREP_INTERRUPT)
+ extra |= BCM2835_DMA_INT_EN;
+ else
+ period_len = buf_len;
/*
* warn if buf_len is not a multiple of period_len - this may leed
@@ -744,6 +745,10 @@
dst = c->cfg.dst_addr;
src = buf_addr;
info |= BCM2835_DMA_D_DREQ | BCM2835_DMA_S_INC;
+
+ /* non-lite channels can write zeroes w/o accessing memory */
+ if (buf_addr == od->zero_page && !c->is_lite_channel)
+ info |= BCM2835_DMA_S_IGNORE;
}
/* calculate number of frames */
@@ -775,14 +780,6 @@
{
struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
- if ((cfg->direction == DMA_DEV_TO_MEM &&
- cfg->src_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES) ||
- (cfg->direction == DMA_MEM_TO_DEV &&
- cfg->dst_addr_width != DMA_SLAVE_BUSWIDTH_4_BYTES) ||
- !is_slave_direction(cfg->direction)) {
- return -EINVAL;
- }
-
c->cfg = *cfg;
return 0;
@@ -791,16 +788,10 @@
static int bcm2835_dma_terminate_all(struct dma_chan *chan)
{
struct bcm2835_chan *c = to_bcm2835_dma_chan(chan);
- struct bcm2835_dmadev *d = to_bcm2835_dma_dev(c->vc.chan.device);
unsigned long flags;
LIST_HEAD(head);
spin_lock_irqsave(&c->vc.lock, flags);
-
- /* Prevent this channel being scheduled */
- spin_lock(&d->lock);
- list_del_init(&c->node);
- spin_unlock(&d->lock);
/* stop DMA activity */
if (c->desc) {
@@ -834,7 +825,6 @@
c->vc.desc_free = bcm2835_dma_desc_free;
vchan_init(&c->vc, &d->ddev);
- INIT_LIST_HEAD(&c->node);
c->chan_base = BCM2835_DMA_CHANIO(d->base, chan_id);
c->ch = chan_id;
@@ -858,6 +848,9 @@
list_del(&c->vc.chan.device_node);
tasklet_kill(&c->vc.task);
}
+
+ dma_unmap_page_attrs(od->ddev.dev, od->zero_page, PAGE_SIZE,
+ DMA_TO_DEVICE, DMA_ATTR_SKIP_CPU_SYNC);
}
static const struct of_device_id bcm2835_dma_of_match[] = {
@@ -907,7 +900,6 @@
if (!od)
return -ENOMEM;
- pdev->dev.dma_parms = &od->dma_parms;
dma_set_max_seg_size(&pdev->dev, 0x3FFFFFFF);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -920,7 +912,6 @@
dma_cap_set(DMA_SLAVE, od->ddev.cap_mask);
dma_cap_set(DMA_PRIVATE, od->ddev.cap_mask);
dma_cap_set(DMA_CYCLIC, od->ddev.cap_mask);
- dma_cap_set(DMA_SLAVE, od->ddev.cap_mask);
dma_cap_set(DMA_MEMCPY, od->ddev.cap_mask);
od->ddev.device_alloc_chan_resources = bcm2835_dma_alloc_chan_resources;
od->ddev.device_free_chan_resources = bcm2835_dma_free_chan_resources;
@@ -937,11 +928,19 @@
od->ddev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV) |
BIT(DMA_MEM_TO_MEM);
od->ddev.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
+ od->ddev.descriptor_reuse = true;
od->ddev.dev = &pdev->dev;
INIT_LIST_HEAD(&od->ddev.channels);
- spin_lock_init(&od->lock);
platform_set_drvdata(pdev, od);
+
+ od->zero_page = dma_map_page_attrs(od->ddev.dev, ZERO_PAGE(0), 0,
+ PAGE_SIZE, DMA_TO_DEVICE,
+ DMA_ATTR_SKIP_CPU_SYNC);
+ if (dma_mapping_error(od->ddev.dev, od->zero_page)) {
+ dev_err(&pdev->dev, "Failed to map zero page\n");
+ return -ENOMEM;
+ }
/* Request DMA channel mask from device tree */
if (of_property_read_u32(pdev->dev.of_node,
@@ -1046,4 +1045,4 @@
MODULE_ALIAS("platform:bcm2835-dma");
MODULE_DESCRIPTION("BCM2835 DMA engine driver");
MODULE_AUTHOR("Florian Meier <florian.meier@koalo.de>");
-MODULE_LICENSE("GPL v2");
+MODULE_LICENSE("GPL");
--
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