From: Joy Chakraborty <joychakr@google.com>
To: Mark Brown <broonie@kernel.org>
Cc: linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org,
manugautam@google.com, Joy Chakraborty <joychakr@google.com>,
Serge Semin <fancer.lancer@gmail.com>
Subject: [PATCH v11 1/3] spi: dw: Add DMA directional capability check
Date: Fri, 12 May 2023 10:47:43 +0000 [thread overview]
Message-ID: <20230512104746.1797865-2-joychakr@google.com> (raw)
In-Reply-To: <20230512104746.1797865-1-joychakr@google.com>
Check capabilities of DMA controller during init to make sure it is
capable of handling MEM2DEV for tx channel, DEV2MEM for rx channel.
Current DW DMA driver requires both tx and rx channel to be configured
and functional for any kind of transfers to take effect including
half duplex. Hence, check for both tx and rx direction and fail on
unavailbility of either.
Signed-off-by: Joy Chakraborty <joychakr@google.com>
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
Tested-by: Serge Semin <fancer.lancer@gmail.com>
* tested on Baikal-T1 based system with DW SPI-looped back interface
transferring a chunk of data with DFS:8,12,16.
---
drivers/spi/spi-dw-dma.c | 41 +++++++++++++++++++++++++++++++---------
1 file changed, 32 insertions(+), 9 deletions(-)
diff --git a/drivers/spi/spi-dw-dma.c b/drivers/spi/spi-dw-dma.c
index f19c092920a1..2363317a0dca 100644
--- a/drivers/spi/spi-dw-dma.c
+++ b/drivers/spi/spi-dw-dma.c
@@ -72,12 +72,22 @@ static void dw_spi_dma_maxburst_init(struct dw_spi *dws)
dw_writel(dws, DW_SPI_DMATDLR, dws->txburst);
}
-static void dw_spi_dma_sg_burst_init(struct dw_spi *dws)
+static int dw_spi_dma_caps_init(struct dw_spi *dws)
{
- struct dma_slave_caps tx = {0}, rx = {0};
+ struct dma_slave_caps tx, rx;
+ int ret;
+
+ ret = dma_get_slave_caps(dws->txchan, &tx);
+ if (ret)
+ return ret;
- dma_get_slave_caps(dws->txchan, &tx);
- dma_get_slave_caps(dws->rxchan, &rx);
+ ret = dma_get_slave_caps(dws->rxchan, &rx);
+ if (ret)
+ return ret;
+
+ if (!(tx.directions & BIT(DMA_MEM_TO_DEV) &&
+ rx.directions & BIT(DMA_DEV_TO_MEM)))
+ return -ENXIO;
if (tx.max_sg_burst > 0 && rx.max_sg_burst > 0)
dws->dma_sg_burst = min(tx.max_sg_burst, rx.max_sg_burst);
@@ -87,6 +97,8 @@ static void dw_spi_dma_sg_burst_init(struct dw_spi *dws)
dws->dma_sg_burst = rx.max_sg_burst;
else
dws->dma_sg_burst = 0;
+
+ return 0;
}
static int dw_spi_dma_init_mfld(struct device *dev, struct dw_spi *dws)
@@ -95,6 +107,7 @@ static int dw_spi_dma_init_mfld(struct device *dev, struct dw_spi *dws)
struct dw_dma_slave dma_rx = { .src_id = 0 }, *rx = &dma_rx;
struct pci_dev *dma_dev;
dma_cap_mask_t mask;
+ int ret = -EBUSY;
/*
* Get pci device for DMA controller, currently it could only
@@ -124,20 +137,25 @@ static int dw_spi_dma_init_mfld(struct device *dev, struct dw_spi *dws)
init_completion(&dws->dma_completion);
- dw_spi_dma_maxburst_init(dws);
+ ret = dw_spi_dma_caps_init(dws);
+ if (ret)
+ goto free_txchan;
- dw_spi_dma_sg_burst_init(dws);
+ dw_spi_dma_maxburst_init(dws);
pci_dev_put(dma_dev);
return 0;
+free_txchan:
+ dma_release_channel(dws->txchan);
+ dws->txchan = NULL;
free_rxchan:
dma_release_channel(dws->rxchan);
dws->rxchan = NULL;
err_exit:
pci_dev_put(dma_dev);
- return -EBUSY;
+ return ret;
}
static int dw_spi_dma_init_generic(struct device *dev, struct dw_spi *dws)
@@ -163,12 +181,17 @@ static int dw_spi_dma_init_generic(struct device *dev, struct dw_spi *dws)
init_completion(&dws->dma_completion);
- dw_spi_dma_maxburst_init(dws);
+ ret = dw_spi_dma_caps_init(dws);
+ if (ret)
+ goto free_txchan;
- dw_spi_dma_sg_burst_init(dws);
+ dw_spi_dma_maxburst_init(dws);
return 0;
+free_txchan:
+ dma_release_channel(dws->txchan);
+ dws->txchan = NULL;
free_rxchan:
dma_release_channel(dws->rxchan);
dws->rxchan = NULL;
--
2.40.1.606.ga4b1b128d6-goog
next prev parent reply other threads:[~2023-05-12 10:48 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-12 10:47 [PATCH v11 0/3] spi: dw: DW SPI DMA Driver updates Joy Chakraborty
2023-05-12 10:47 ` Joy Chakraborty [this message]
2023-05-12 10:47 ` [PATCH v11 2/3] spi: dw: Add DMA address widths capability check Joy Chakraborty
2023-05-12 10:47 ` [PATCH v11 3/3] spi: dw: Round of n_bytes to power of 2 Joy Chakraborty
2023-05-17 23:03 ` Andy Shevchenko
2023-05-15 15:22 ` [PATCH v11 0/3] spi: dw: DW SPI DMA Driver updates Mark Brown
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20230512104746.1797865-2-joychakr@google.com \
--to=joychakr@google.com \
--cc=broonie@kernel.org \
--cc=fancer.lancer@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-spi@vger.kernel.org \
--cc=manugautam@google.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.