[PATCH v2 1/3] dmaengine: sun6i: support parameterized compatible strings
Chen-Yu Tsai
wens at csie.org
Wed Sep 17 20:24:38 PDT 2014
This patch adds support for hardware parameters tied to compatible
strings, so similar hardware can reuse the driver.
Signed-off-by: Chen-Yu Tsai <wens at csie.org>
Acked-by: Maxime Ripard <maxime.ripard at free-electrons.com>
---
drivers/dma/sun6i-dma.c | 96 +++++++++++++++++++++++++++++++------------------
1 file changed, 61 insertions(+), 35 deletions(-)
diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c
index 3aa10b3..89ca0c4 100644
--- a/drivers/dma/sun6i-dma.c
+++ b/drivers/dma/sun6i-dma.c
@@ -18,6 +18,7 @@
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/of_dma.h>
+#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/reset.h>
#include <linux/slab.h>
@@ -26,24 +27,6 @@
#include "virt-dma.h"
/*
- * There's 16 physical channels that can work in parallel.
- *
- * However we have 30 different endpoints for our requests.
- *
- * Since the channels are able to handle only an unidirectional
- * transfer, we need to allocate more virtual channels so that
- * everyone can grab one channel.
- *
- * Some devices can't work in both direction (mostly because it
- * wouldn't make sense), so we have a bit fewer virtual channels than
- * 2 channels per endpoints.
- */
-
-#define NR_MAX_CHANNELS 16
-#define NR_MAX_REQUESTS 30
-#define NR_MAX_VCHANS 53
-
-/*
* Common registers
*/
#define DMA_IRQ_EN(x) ((x) * 0x04)
@@ -102,6 +85,19 @@
#define DRQ_SDRAM 1
/*
+ * Hardware channels / ports representation
+ *
+ * The hardware is used in several SoCs, with differing numbers
+ * of channels and endpoints. This structure ties those numbers
+ * to a certain compatible string.
+ */
+struct sun6i_dma_config {
+ u32 nr_max_channels;
+ u32 nr_max_requests;
+ u32 nr_max_vchans;
+};
+
+/*
* Hardware representation of the LLI
*
* The hardware will be fed the physical address of this structure,
@@ -159,6 +155,7 @@ struct sun6i_dma_dev {
struct dma_pool *pool;
struct sun6i_pchan *pchans;
struct sun6i_vchan *vchans;
+ const struct sun6i_dma_config *cfg;
};
static struct device *chan2dev(struct dma_chan *chan)
@@ -432,6 +429,7 @@ static int sun6i_dma_start_desc(struct sun6i_vchan *vchan)
static void sun6i_dma_tasklet(unsigned long data)
{
struct sun6i_dma_dev *sdev = (struct sun6i_dma_dev *)data;
+ const struct sun6i_dma_config *cfg = sdev->cfg;
struct sun6i_vchan *vchan;
struct sun6i_pchan *pchan;
unsigned int pchan_alloc = 0;
@@ -459,7 +457,7 @@ static void sun6i_dma_tasklet(unsigned long data)
}
spin_lock_irq(&sdev->lock);
- for (pchan_idx = 0; pchan_idx < NR_MAX_CHANNELS; pchan_idx++) {
+ for (pchan_idx = 0; pchan_idx < cfg->nr_max_channels; pchan_idx++) {
pchan = &sdev->pchans[pchan_idx];
if (pchan->vchan || list_empty(&sdev->pending))
@@ -480,7 +478,7 @@ static void sun6i_dma_tasklet(unsigned long data)
}
spin_unlock_irq(&sdev->lock);
- for (pchan_idx = 0; pchan_idx < NR_MAX_CHANNELS; pchan_idx++) {
+ for (pchan_idx = 0; pchan_idx < cfg->nr_max_channels; pchan_idx++) {
if (!(pchan_alloc & BIT(pchan_idx)))
continue;
@@ -502,7 +500,7 @@ static irqreturn_t sun6i_dma_interrupt(int irq, void *dev_id)
int i, j, ret = IRQ_NONE;
u32 status;
- for (i = 0; i < 2; i++) {
+ for (i = 0; i < sdev->cfg->nr_max_channels / DMA_IRQ_CHAN_NR; i++) {
status = readl(sdev->base + DMA_IRQ_STAT(i));
if (!status)
continue;
@@ -512,7 +510,7 @@ static irqreturn_t sun6i_dma_interrupt(int irq, void *dev_id)
writel(status, sdev->base + DMA_IRQ_STAT(i));
- for (j = 0; (j < 8) && status; j++) {
+ for (j = 0; (j < DMA_IRQ_CHAN_NR) && status; j++) {
if (status & DMA_IRQ_QUEUE) {
pchan = sdev->pchans + j;
vchan = pchan->vchan;
@@ -525,7 +523,7 @@ static irqreturn_t sun6i_dma_interrupt(int irq, void *dev_id)
}
}
- status = status >> 4;
+ status = status >> DMA_IRQ_CHAN_WIDTH;
}
if (!atomic_read(&sdev->tasklet_shutdown))
@@ -817,7 +815,7 @@ static struct dma_chan *sun6i_dma_of_xlate(struct of_phandle_args *dma_spec,
struct dma_chan *chan;
u8 port = dma_spec->args[0];
- if (port > NR_MAX_REQUESTS)
+ if (port > sdev->cfg->nr_max_requests)
return NULL;
chan = dma_get_any_slave_channel(&sdev->slave);
@@ -850,7 +848,7 @@ static inline void sun6i_dma_free(struct sun6i_dma_dev *sdev)
{
int i;
- for (i = 0; i < NR_MAX_VCHANS; i++) {
+ for (i = 0; i < sdev->cfg->nr_max_vchans; i++) {
struct sun6i_vchan *vchan = &sdev->vchans[i];
list_del(&vchan->vc.chan.device_node);
@@ -858,8 +856,36 @@ static inline void sun6i_dma_free(struct sun6i_dma_dev *sdev)
}
}
+/*
+ * For A31:
+ *
+ * There's 16 physical channels that can work in parallel.
+ *
+ * However we have 30 different endpoints for our requests.
+ *
+ * Since the channels are able to handle only an unidirectional
+ * transfer, we need to allocate more virtual channels so that
+ * everyone can grab one channel.
+ *
+ * Some devices can't work in both direction (mostly because it
+ * wouldn't make sense), so we have a bit fewer virtual channels than
+ * 2 channels per endpoints.
+ */
+
+static struct sun6i_dma_config sun6i_a31_dma_cfg = {
+ .nr_max_channels = 16,
+ .nr_max_requests = 30,
+ .nr_max_vchans = 53,
+};
+
+static struct of_device_id sun6i_dma_match[] = {
+ { .compatible = "allwinner,sun6i-a31-dma", .data = &sun6i_a31_dma_cfg },
+ { /* sentinel */ }
+};
+
static int sun6i_dma_probe(struct platform_device *pdev)
{
+ const struct of_device_id *device;
struct sun6i_dma_dev *sdc;
struct resource *res;
int ret, i;
@@ -868,6 +894,11 @@ static int sun6i_dma_probe(struct platform_device *pdev)
if (!sdc)
return -ENOMEM;
+ device = of_match_device(sun6i_dma_match, &pdev->dev);
+ if (!device)
+ return -ENODEV;
+ sdc->cfg = device->data;
+
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
sdc->base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(sdc->base))
@@ -914,30 +945,30 @@ static int sun6i_dma_probe(struct platform_device *pdev)
sdc->slave.device_prep_slave_sg = sun6i_dma_prep_slave_sg;
sdc->slave.device_prep_dma_memcpy = sun6i_dma_prep_dma_memcpy;
sdc->slave.device_control = sun6i_dma_control;
- sdc->slave.chancnt = NR_MAX_VCHANS;
+ sdc->slave.chancnt = sdc->cfg->nr_max_vchans;
sdc->slave.dev = &pdev->dev;
- sdc->pchans = devm_kcalloc(&pdev->dev, NR_MAX_CHANNELS,
+ sdc->pchans = devm_kcalloc(&pdev->dev, sdc->cfg->nr_max_channels,
sizeof(struct sun6i_pchan), GFP_KERNEL);
if (!sdc->pchans)
return -ENOMEM;
- sdc->vchans = devm_kcalloc(&pdev->dev, NR_MAX_VCHANS,
+ sdc->vchans = devm_kcalloc(&pdev->dev, sdc->cfg->nr_max_vchans,
sizeof(struct sun6i_vchan), GFP_KERNEL);
if (!sdc->vchans)
return -ENOMEM;
tasklet_init(&sdc->task, sun6i_dma_tasklet, (unsigned long)sdc);
- for (i = 0; i < NR_MAX_CHANNELS; i++) {
+ for (i = 0; i < sdc->cfg->nr_max_channels; i++) {
struct sun6i_pchan *pchan = &sdc->pchans[i];
pchan->idx = i;
pchan->base = sdc->base + 0x100 + i * 0x40;
}
- for (i = 0; i < NR_MAX_VCHANS; i++) {
+ for (i = 0; i < sdc->cfg->nr_max_vchans; i++) {
struct sun6i_vchan *vchan = &sdc->vchans[i];
INIT_LIST_HEAD(&vchan->node);
@@ -1009,11 +1040,6 @@ static int sun6i_dma_remove(struct platform_device *pdev)
return 0;
}
-static struct of_device_id sun6i_dma_match[] = {
- { .compatible = "allwinner,sun6i-a31-dma" },
- { /* sentinel */ }
-};
-
static struct platform_driver sun6i_dma_driver = {
.probe = sun6i_dma_probe,
.remove = sun6i_dma_remove,
--
2.1.0
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