Le 11/08/2024 à 07:16, Inochi Amaoto a écrit :
Sophgo CV18XX/SG200X use DW AXI CORE with a multiplexer for remapping
its request lines. The multiplexer supports at most 8 request lines.
Add driver for Sophgo CV18XX/SG200X DMA multiplexer.
Signed-off-by: Inochi Amaoto <inochiama@xxxxxxxxxxx>
---
Hi,
...
+static void *cv1800_dmamux_route_allocate(struct of_phandle_args *dma_spec,
+ struct of_dma *ofdma)
+{
+ struct platform_device *pdev = of_find_device_by_node(ofdma->of_node);
+ struct cv1800_dmamux_data *dmamux = platform_get_drvdata(pdev);
+ struct cv1800_dmamux_map *map;
+ struct llist_node *node;
+ unsigned long flags;
+ unsigned int chid, devid, cpuid;
+ int ret;
+
+ if (dma_spec->args_count != DMAMUX_NCELLS) {
+ dev_err(&pdev->dev, "invalid number of dma mux args\n");
+ return ERR_PTR(-EINVAL);
+ }
+
+ devid = dma_spec->args[0];
+ cpuid = dma_spec->args[1];
+ dma_spec->args_count = 1;
+
+ if (devid > MAX_DMA_MAPPING_ID) {
+ dev_err(&pdev->dev, "invalid device id: %u\n", devid);
+ return ERR_PTR(-EINVAL);
+ }
+
+ if (cpuid > MAX_DMA_CPU_ID) {
+ dev_err(&pdev->dev, "invalid cpu id: %u\n", cpuid);
+ return ERR_PTR(-EINVAL);
+ }
+
+ dma_spec->np = of_parse_phandle(ofdma->of_node, "dma-masters", 0);
+ if (!dma_spec->np) {
+ dev_err(&pdev->dev, "can't get dma master\n");
+ return ERR_PTR(-EINVAL);
+ }
+
+ spin_lock_irqsave(&dmamux->lock, flags);
+
+ if (test_bit(devid, dmamux->mapped_peripherals)) {
+ llist_for_each_entry(map, dmamux->reserve_maps.first, node) {
+ if (map->peripheral == devid && map->cpu == cpuid)
+ goto found;
+ }
+
+ ret = -EINVAL;
+ goto failed;
+ } else {
+ node = llist_del_first(&dmamux->free_maps);
+ if (!node) {
+ ret = -ENODEV;
+ goto failed;
+ }
+
+ map = llist_entry(node, struct cv1800_dmamux_map, node);
+ llist_add(&map->node, &dmamux->reserve_maps);
+ set_bit(devid, dmamux->mapped_peripherals);
+ }
+
+found:
+ chid = map->channel;
+ map->peripheral = devid;
+ map->cpu = cpuid;
+
+ regmap_set_bits(dmamux->regmap,
+ DMAMUX_CH_REG(chid),
+ DMAMUX_CH_SET(chid, devid));
+
+ regmap_update_bits(dmamux->regmap, CV1800_SDMA_DMA_INT_MUX,
+ DMAMUX_INT_CH_MASK(chid, cpuid),
+ DMAMUX_INT_CH_BIT(chid, cpuid));
+
+ spin_unlock_irqrestore(&dmamux->lock, flags);
+
+ dma_spec->args[0] = chid;
+
+ dev_dbg(&pdev->dev, "register channel %u for req %u (cpu %u)\n",
+ chid, devid, cpuid);
+
+ return map;
+
+failed:
+ spin_unlock_irqrestore(&dmamux->lock, flags);
+ of_node_put(dma_spec->np);
+ dev_err(&pdev->dev, "errno %d\n", ret);
+ return ERR_PTR(ret);
+
Nitpick: Unneeded empty new line.
+}
+
+static int cv1800_dmamux_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *mux_node = dev->of_node;
+ struct cv1800_dmamux_data *data;
+ struct cv1800_dmamux_map *tmp;
+ struct device *parent = dev->parent;
+ struct regmap *regmap = NULL;
+ unsigned int i;
+
+ if (!parent)
+ return -ENODEV;
+
+ regmap = device_node_to_regmap(parent->of_node);
+ if (IS_ERR(regmap))
+ return PTR_ERR(regmap);
+
+ data = devm_kmalloc(dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ spin_lock_init(&data->lock);
+ init_llist_head(&data->free_maps);
Why init free_maps and not reserve_maps?
'data' is not zeroed, so it should be needed, IMHO.
Same for mapped_peripherals. It is not initialized.
I think that using devm_kzalloc() above is needed. (and
init_llist_head(&data->free_maps) could then be removed, if you want)
Just my 2c.
+
+ for (i = 0; i <= MAX_DMA_CH_ID; i++) {
+ tmp = devm_kmalloc(dev, sizeof(*tmp), GFP_KERNEL);
+ if (!tmp) {
+ /* It is OK for not allocating all channel */
+ dev_warn(dev, "can not allocate channel %u\n", i);
+ continue;
+ }
+
+ init_llist_node(&tmp->node);
+ tmp->channel = i;
+ llist_add(&tmp->node, &data->free_maps);
+ }
+
+ /* if no channel is allocated, the probe must fail */
+ if (llist_empty(&data->free_maps))
+ return -ENOMEM;
+
+ data->regmap = regmap;
+ data->dmarouter.dev = dev;
+ data->dmarouter.route_free = cv1800_dmamux_free;
+
+ platform_set_drvdata(pdev, data);
+
+ return of_dma_router_register(mux_node,
+ cv1800_dmamux_route_allocate,
+ &data->dmarouter);
+}
...
CJ
