Re: [PATCH] spi/pxa2xx-pci: Enable DMA binding through device name
From: Mika Westerberg
Date: Fri Jul 25 2014 - 05:58:00 EST
On Fri, Jul 25, 2014 at 12:07:14PM +0300, Mika Westerberg wrote:
> On Fri, Jul 25, 2014 at 10:38:36AM +0200, Arnd Bergmann wrote:
> > On Friday 25 July 2014 11:22:49 Mika Westerberg wrote:
> > > > All you need to do is change your filter function to take the
> > > > slave id from pxa_spi_info and stick it in there, e.g.
> > > >
> > > > static bool pxa2xx_spi_dw_dma_filter(struct dma_chan *chan, void *param)
> > > > {
> > > > const struct pxa2xx_spi_master *pdata = param;
> > > > struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
> > > >
> > > > dwc->request_line = fargs->req;
> > > > dwc->src_master = 0;
> > > > dwc->dst_master = 0;
> > > >
> > > > return 1;
> > > > }
> > >
> > > Oh man. That makes pxa2xx_spi dependent on a certain specific DMA engine
> > > driver.
> >
> > I think you can improve this by putting the filter function (and a pointer
> > to it) into the pxa2xx_spi_master data provided by the PCI driver.
>
> Indeed, that looks better. It still makes the PCI part of the driver
> dependent on a particular DMA engine driver but is certainly better than
> the core pxa2xx_spi driver.
Something like this?
Hock Leong / Chiaue Ee, are you able to check if this works on your BYT
machines?
diff --git a/drivers/spi/spi-pxa2xx-dma.c b/drivers/spi/spi-pxa2xx-dma.c
index c41ff148a2b4..5d46972ffc40 100644
--- a/drivers/spi/spi-pxa2xx-dma.c
+++ b/drivers/spi/spi-pxa2xx-dma.c
@@ -157,7 +157,6 @@ static struct dma_async_tx_descriptor *
pxa2xx_spi_dma_prepare_one(struct driver_data *drv_data,
enum dma_transfer_direction dir)
{
- struct pxa2xx_spi_master *pdata = drv_data->master_info;
struct chip_data *chip = drv_data->cur_chip;
enum dma_slave_buswidth width;
struct dma_slave_config cfg;
@@ -184,7 +183,6 @@ pxa2xx_spi_dma_prepare_one(struct driver_data *drv_data,
cfg.dst_addr = drv_data->ssdr_physical;
cfg.dst_addr_width = width;
cfg.dst_maxburst = chip->dma_burst_size;
- cfg.slave_id = pdata->tx_slave_id;
sgt = &drv_data->tx_sgt;
nents = drv_data->tx_nents;
@@ -193,7 +191,6 @@ pxa2xx_spi_dma_prepare_one(struct driver_data *drv_data,
cfg.src_addr = drv_data->ssdr_physical;
cfg.src_addr_width = width;
cfg.src_maxburst = chip->dma_burst_size;
- cfg.slave_id = pdata->rx_slave_id;
sgt = &drv_data->rx_sgt;
nents = drv_data->rx_nents;
@@ -210,14 +207,6 @@ pxa2xx_spi_dma_prepare_one(struct driver_data *drv_data,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
}
-static bool pxa2xx_spi_dma_filter(struct dma_chan *chan, void *param)
-{
- const struct pxa2xx_spi_master *pdata = param;
-
- return chan->chan_id == pdata->tx_chan_id ||
- chan->chan_id == pdata->rx_chan_id;
-}
-
bool pxa2xx_spi_dma_is_possible(size_t len)
{
return len <= MAX_DMA_LEN;
@@ -321,12 +310,14 @@ int pxa2xx_spi_dma_setup(struct driver_data *drv_data)
return -ENOMEM;
drv_data->tx_chan = dma_request_slave_channel_compat(mask,
- pxa2xx_spi_dma_filter, pdata, dev, "tx");
+ pdata->dma_filter, pdata->dma_filter_param,
+ dev, "tx");
if (!drv_data->tx_chan)
return -ENODEV;
drv_data->rx_chan = dma_request_slave_channel_compat(mask,
- pxa2xx_spi_dma_filter, pdata, dev, "rx");
+ pdata->dma_filter, pdata->dma_filter_param,
+ dev, "rx");
if (!drv_data->rx_chan) {
dma_release_channel(drv_data->tx_chan);
drv_data->tx_chan = NULL;
diff --git a/drivers/spi/spi-pxa2xx-pci.c b/drivers/spi/spi-pxa2xx-pci.c
index c1865c92ccb9..aee3aa9365cf 100644
--- a/drivers/spi/spi-pxa2xx-pci.c
+++ b/drivers/spi/spi-pxa2xx-pci.c
@@ -8,6 +8,9 @@
#include <linux/module.h>
#include <linux/spi/pxa2xx_spi.h>
+#include <linux/dmaengine.h>
+#include "../../drivers/dma/dw/regs.h"
+
enum {
PORT_CE4100,
PORT_BYT,
@@ -23,6 +26,24 @@ struct pxa_spi_info {
int rx_chan_id;
};
+static bool pxa2xx_spi_pci_dma_filter(struct dma_chan *chan, void *param)
+{
+ struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
+ const struct pxa_spi_info *info = param;
+
+ if (chan->chan_id == info->tx_chan_id)
+ dwc->request_line = info->tx_slave_id;
+ else if (chan->chan_id == info->rx_chan_id)
+ dwc->request_line = info->rx_slave_id;
+ else
+ return false;
+
+ dwc->src_master = 0;
+ dwc->dst_master = 0;
+
+ return true;
+}
+
static struct pxa_spi_info spi_info_configs[] = {
[PORT_CE4100] = {
.type = PXA25x_SSP,
@@ -67,10 +88,9 @@ static int pxa2xx_spi_pci_probe(struct pci_dev *dev,
memset(&spi_pdata, 0, sizeof(spi_pdata));
spi_pdata.num_chipselect = (c->num_chipselect > 0) ?
c->num_chipselect : dev->devfn;
- spi_pdata.tx_slave_id = c->tx_slave_id;
- spi_pdata.tx_chan_id = c->tx_chan_id;
- spi_pdata.rx_slave_id = c->rx_slave_id;
- spi_pdata.rx_chan_id = c->rx_chan_id;
+
+ spi_pdata.dma_filter = pxa2xx_spi_pci_dma_filter;
+ spi_pdata.dma_filter_param = c;
spi_pdata.enable_dma = c->rx_slave_id >= 0 && c->tx_slave_id >= 0;
ssp = &spi_pdata.ssp;
diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c
index fe792106bdc5..256c0abbddd2 100644
--- a/drivers/spi/spi-pxa2xx.c
+++ b/drivers/spi/spi-pxa2xx.c
@@ -1062,8 +1062,6 @@ pxa2xx_spi_acpi_get_pdata(struct platform_device *pdev)
pdata->num_chipselect = 1;
pdata->enable_dma = true;
- pdata->tx_chan_id = -1;
- pdata->rx_chan_id = -1;
return pdata;
}
diff --git a/include/linux/spi/pxa2xx_spi.h b/include/linux/spi/pxa2xx_spi.h
index 82d5111cd0c2..2eb00920c169 100644
--- a/include/linux/spi/pxa2xx_spi.h
+++ b/include/linux/spi/pxa2xx_spi.h
@@ -23,6 +23,8 @@
#define PXA2XX_CS_ASSERT (0x01)
#define PXA2XX_CS_DEASSERT (0x02)
+struct dma_chan;
+
/* device.platform_data for SSP controller devices */
struct pxa2xx_spi_master {
u32 clock_enable;
@@ -30,10 +32,8 @@ struct pxa2xx_spi_master {
u8 enable_dma;
/* DMA engine specific config */
- int rx_chan_id;
- int tx_chan_id;
- int rx_slave_id;
- int tx_slave_id;
+ bool (*dma_filter)(struct dma_chan *chan, void *param);
+ void *dma_filter_param;
/* For non-PXA arches */
struct ssp_device ssp;
--
2.0.1
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