From: Stephen Warren <swarren@xxxxxxxxxx>
Call of_dma_controller_register() so that DMA clients can look up the
Tegra DMA controller using standard APIs. This requires the of_xlate()
function to save off the DMA slave ID, and for tegra_dma_slave_config()
not to over-write this information; once DMA client drivers are converted
to dma_request_slave_channel() and DT-based lookups, they won't set this
field of struct dma_slave_config anymore.
Cc: linux-tegra@xxxxxxxxxxxxxxx
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Vinod Koul <vinod.koul@xxxxxxxxx>
Cc: dmaengine@xxxxxxxxxxxxxxx
Signed-off-by: Stephen Warren <swarren@xxxxxxxxxx>
Acked-by: Arnd Bergmann <arnd@xxxxxxxx>
Reviewed-by: Thierry Reding <treding@xxxxxxxxxx>
---
(just reposting this in order to get an ack from one of the dmaengine
maintainers)
v3:
* Rework of_xlate() to use new dma_get_any_slave_channel().
v2:
* Use of_dma_slave_xlate() rather than of_dma_simple_xlate(), as
suggested by Arnd Bergmann.
This patch is part of a series with strong internal depdendencies. I'm
looking for an ack so that I can take the entire series through the Tegra
and arm-soc trees. The series will be part of a stable branch that can be
merged into other subsystems if needed to avoid/resolve dependencies.
---
drivers/dma/tegra20-apb-dma.c | 39 ++++++++++++++++++++++++++++++++++++---
1 file changed, 36 insertions(+), 3 deletions(-)
diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c
index afa5844c9346..d11bb3620f27 100644
--- a/drivers/dma/tegra20-apb-dma.c
+++ b/drivers/dma/tegra20-apb-dma.c
@@ -1,7 +1,7 @@
/*
* DMA driver for Nvidia's Tegra20 APB DMA controller.
*
- * Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved.
+ * Copyright (c) 2012-2013, NVIDIA CORPORATION. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
@@ -29,6 +29,7 @@
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
+#include <linux/of_dma.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/pm_runtime.h>
@@ -199,6 +200,7 @@ struct tegra_dma_channel {
void *callback_param;
/* Channel-slave specific configuration */
+ unsigned int slave_id;
struct dma_slave_config dma_sconfig;
struct tegra_dma_channel_regs channel_reg;
};
@@ -340,6 +342,8 @@ static int tegra_dma_slave_config(struct dma_chan *dc,
}
memcpy(&tdc->dma_sconfig, sconfig, sizeof(*sconfig));
+ if (!tdc->slave_id)
+ tdc->slave_id = sconfig->slave_id;
tdc->config_init = true;
return 0;
}
@@ -942,7 +946,7 @@ static struct dma_async_tx_descriptor *tegra_dma_prep_slave_sg(
ahb_seq |= TEGRA_APBDMA_AHBSEQ_BUS_WIDTH_32;
csr |= TEGRA_APBDMA_CSR_ONCE | TEGRA_APBDMA_CSR_FLOW;
- csr |= tdc->dma_sconfig.slave_id << TEGRA_APBDMA_CSR_REQ_SEL_SHIFT;
+ csr |= tdc->slave_id << TEGRA_APBDMA_CSR_REQ_SEL_SHIFT;
if (flags & DMA_PREP_INTERRUPT)
csr |= TEGRA_APBDMA_CSR_IE_EOC;
@@ -1086,7 +1090,7 @@ static struct dma_async_tx_descriptor *tegra_dma_prep_dma_cyclic(
csr |= TEGRA_APBDMA_CSR_FLOW;
if (flags & DMA_PREP_INTERRUPT)
csr |= TEGRA_APBDMA_CSR_IE_EOC;
- csr |= tdc->dma_sconfig.slave_id << TEGRA_APBDMA_CSR_REQ_SEL_SHIFT;
+ csr |= tdc->slave_id << TEGRA_APBDMA_CSR_REQ_SEL_SHIFT;
apb_seq |= TEGRA_APBDMA_APBSEQ_WRAP_WORD_1;
@@ -1206,6 +1210,25 @@ static void tegra_dma_free_chan_resources(struct dma_chan *dc)
kfree(sg_req);
}
clk_disable_unprepare(tdma->dma_clk);
+
+ tdc->slave_id = 0;
+}
+
+static struct dma_chan *tegra_dma_of_xlate(struct of_phandle_args *dma_spec,
+ struct of_dma *ofdma)
+{
+ struct tegra_dma *tdma = ofdma->of_dma_data;
+ struct dma_chan *chan;
+ struct tegra_dma_channel *tdc;
+
+ chan = dma_get_any_slave_channel(&tdma->dma_dev);
+ if (!chan)
+ return NULL;
+
+ tdc = to_tegra_dma_chan(chan);
+ tdc->slave_id = dma_spec->args[0];
+
+ return chan;
}
/* Tegra20 specific DMA controller information */
@@ -1383,10 +1406,20 @@ static int tegra_dma_probe(struct platform_device *pdev)
goto err_irq;
}
+ ret = of_dma_controller_register(pdev->dev.of_node,
+ tegra_dma_of_xlate, tdma);
+ if (ret < 0) {
+ dev_err(&pdev->dev,
+ "Tegra20 APB DMA OF registration failed %d\n", ret);
+ goto err_unregister_dma_dev;
+ }
+
dev_info(&pdev->dev, "Tegra20 APB DMA driver register %d channels\n",
cdata->nr_channels);
return 0;
+err_unregister_dma_dev:
+ dma_async_device_unregister(&tdma->dma_dev);
err_irq:
while (--i >= 0) {
struct tegra_dma_channel *tdc = &tdma->channels[i];
--
1.8.1.5
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