[PATCH v3 08/13] ARM: edma: Get IP configuration from HW (number of channels, tc, etc)

Peter Ujfalusi
2014-05-16T12:18:25Z

>From CCCFG register of eDMA3 we can get all the needed information for the
driver about the IP:
Number of channels: NUM_DMACH
Number of regions: NUM_REGN
Number of slots (PaRAM sets): NUM_PAENTRY
Number of TC/EQ: NUM_EVQUE

In case when booted with DT or the queue_priority_mapping is not provided
set up a default priority map.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
---
arch/arm/common/edma.c | 115 +++++++++++++++++++++++++++++++------------------
1 file changed, 73 insertions(+), 42 deletions(-)

diff --git a/arch/arm/common/edma.c b/arch/arm/common/edma.c
index aa9473cb0c23..485be42519b9 100644
--- a/arch/arm/common/edma.c
+++ b/arch/arm/common/edma.c
@@ -102,7 +102,13 @@
#define PARM_OFFSET(param_no) (EDMA_PARM + ((param_no) << 5))

#define EDMA_DCHMAP 0x0100 /* 64 registers */
-#define CHMAP_EXIST BIT(24)
+
+/* CCCFG register */
+#define GET_NUM_DMACH(x) (x & 0x7) /* bits 0-2 */
+#define GET_NUM_PAENTRY(x) ((x & 0x7000) >> 12) /* bits 12-14 */
+#define GET_NUM_EVQUE(x) ((x & 0x70000) >> 16) /* bits 16-18 */
+#define GET_NUM_REGN(x) ((x & 0x300000) >> 20) /* bits 20-21 */
+#define CHMAP_EXIST BIT(24)

#define EDMA_MAX_DMACH 64
#define EDMA_MAX_PARAMENTRY 512
@@ -1408,6 +1414,67 @@ void edma_clear_event(unsigned channel)
}
EXPORT_SYMBOL(edma_clear_event);

+static int edma_setup_from_hw(struct device *dev, struct edma_soc_info *pdata,
+ struct edma *edma_cc)
+{
+ int i;
+ u32 value, cccfg;
+ s8 (*queue_priority_map)[2];
+
+ /* Decode the eDMA3 configuration from CCCFG register */
+ cccfg = edma_read(0, EDMA_CCCFG);
+
+ value = GET_NUM_REGN(cccfg);
+ edma_cc->num_region = BIT(value);
+
+ value = GET_NUM_DMACH(cccfg);
+ edma_cc->num_channels = BIT(value + 1);
+
+ value = GET_NUM_PAENTRY(cccfg);
+ edma_cc->num_slots = BIT(value + 4);
+
+ value = GET_NUM_EVQUE(cccfg);
+ edma_cc->num_tc = value + 1;
+
+ dev_dbg(dev, "eDMA3 HW configuration (cccfg: 0x%08x):\n", cccfg);
+ dev_dbg(dev, "num_region: %u\n", edma_cc->num_region);
+ dev_dbg(dev, "num_channel: %u\n", edma_cc->num_channels);
+ dev_dbg(dev, "num_slot: %u\n", edma_cc->num_slots);
+ dev_dbg(dev, "num_tc: %u\n", edma_cc->num_tc);
+
+ /* Nothing need to be done if queue priority is provided */
+ if (pdata->queue_priority_mapping)
+ return 0;
+
+ /*
+ * Configure TC/queue priority as follows:
+ * Q0 - priority 0
+ * Q1 - priority 1
+ * Q2 - priority 2
+ * ...
+ * The meaning of priority numbers: 0 highest priority, 7 lowest
+ * priority. So Q0 is the highest priority queue and the last queue has
+ * the lowest priority.
+ */
+ queue_priority_map = devm_kzalloc(dev,
+ (edma_cc->num_tc + 1) * sizeof(s8),
+ GFP_KERNEL);
+ if (!queue_priority_map)
+ return -ENOMEM;
+
+ for (i = 0; i < edma_cc->num_tc; i++) {
+ queue_priority_map[i][0] = i;
+ queue_priority_map[i][1] = i;
+ }
+ queue_priority_map[i][0] = -1;
+ queue_priority_map[i][1] = -1;
+
+ pdata->queue_priority_mapping = queue_priority_map;
+ pdata->default_queue = 0;
+
+ return 0;
+}
+
#if IS_ENABLED(CONFIG_OF) && IS_ENABLED(CONFIG_DMADEVICES)

static int edma_xbar_event_map(struct device *dev, struct device_node *node,
@@ -1458,50 +1525,16 @@ static int edma_of_parse_dt(struct device *dev,
struct device_node *node,
struct edma_soc_info *pdata)
{
- int ret = 0, i;
- u32 value;
+ int ret = 0;
struct property *prop;
size_t sz;
struct edma_rsv_info *rsv_info;
- s8 (*queue_priority_map)[2];
-
- ret = of_property_read_u32(node, "dma-channels", &value);
- if (ret < 0)
- return ret;
- pdata->n_channel = value;
-
- ret = of_property_read_u32(node, "ti,edma-regions", &value);
- if (ret < 0)
- return ret;
- pdata->n_region = value;
-
- ret = of_property_read_u32(node, "ti,edma-slots", &value);
- if (ret < 0)
- return ret;
- pdata->n_slot = value;
-
- pdata->n_tc = 3;

rsv_info = devm_kzalloc(dev, sizeof(struct edma_rsv_info), GFP_KERNEL);
if (!rsv_info)
return -ENOMEM;
pdata->rsv = rsv_info;

- queue_priority_map = devm_kzalloc(dev, 8*sizeof(s8), GFP_KERNEL);
- if (!queue_priority_map)
- return -ENOMEM;
-
- for (i = 0; i < 3; i++) {
- queue_priority_map[i][0] = i;
- queue_priority_map[i][1] = i;
- }
- queue_priority_map[i][0] = -1;
- queue_priority_map[i][1] = -1;
-
- pdata->queue_priority_mapping = queue_priority_map;
-
- pdata->default_queue = 0;
-
prop = of_find_property(node, "ti,edma-xbar-event-map", &sz);
if (prop)
ret = edma_xbar_event_map(dev, node, pdata, sz);
@@ -1621,14 +1654,12 @@ static int edma_probe(struct platform_device *pdev)
if (!edma_cc[j])
return -ENOMEM;

- edma_cc[j]->num_channels = min_t(unsigned, info[j]->n_channel,
- EDMA_MAX_DMACH);
- edma_cc[j]->num_slots = min_t(unsigned, info[j]->n_slot,
- EDMA_MAX_PARAMENTRY);
- edma_cc[j]->num_tc = info[j]->n_tc;
+ /* Get eDMA3 configuration from IP */
+ ret = edma_setup_from_hw(dev, info[j], edma_cc[j]);
+ if (ret)
+ return ret;

edma_cc[j]->default_queue = info[j]->default_queue;
- edma_cc[j]->num_region = info[j]->n_region;

dev_dbg(&pdev->dev, "DMA REG BASE ADDR=%p\n",
edmacc_regs_base[j]);
--
1.9.3