--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2025 Inochi Amaoto <inochiama@gmail.com>
+ */
+
+#include <linux/bitops.h>
+#include <linux/cleanup.h>
+#include <linux/module.h>
+#include <linux/of_dma.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/llist.h>
+#include <linux/regmap.h>
+#include <linux/spinlock.h>
+#include <linux/mfd/syscon.h>
+
+#define REG_DMA_CHANNEL_REMAP0 0x154
+#define REG_DMA_CHANNEL_REMAP1 0x158
+#define REG_DMA_INT_MUX 0x298
+
+#define DMAMUX_NCELLS 2
+#define MAX_DMA_MAPPING_ID 42
+#define MAX_DMA_CPU_ID 2
+#define MAX_DMA_CH_ID 7
+
+#define DMAMUX_INTMUX_REGISTER_LEN 4
+#define DMAMUX_NR_CH_PER_REGISTER 4
+#define DMAMUX_BIT_PER_CH 8
+#define DMAMUX_CH_MASk GENMASK(5, 0)
+#define DMAMUX_INT_BIT_PER_CPU 10
+#define DMAMUX_CH_UPDATE_BIT BIT(31)
+
+#define DMAMUX_CH_REGPOS(chid) \
+ ((chid) / DMAMUX_NR_CH_PER_REGISTER)
+#define DMAMUX_CH_REGOFF(chid) \
+ ((chid) % DMAMUX_NR_CH_PER_REGISTER)
+#define DMAMUX_CH_REG(chid) \
+ ((DMAMUX_CH_REGPOS(chid) * sizeof(u32)) + \
+ REG_DMA_CHANNEL_REMAP0)
+#define DMAMUX_CH_SET(chid, val) \
+ (((val) << (DMAMUX_CH_REGOFF(chid) * DMAMUX_BIT_PER_CH)) | \
+ DMAMUX_CH_UPDATE_BIT)
+#define DMAMUX_CH_MASK(chid) \
+ DMAMUX_CH_SET(chid, DMAMUX_CH_MASk)
+
+#define DMAMUX_INT_BIT(chid, cpuid) \
+ BIT((cpuid) * DMAMUX_INT_BIT_PER_CPU + (chid))
+#define DMAMUX_INTEN_BIT(cpuid) \
+ DMAMUX_INT_BIT(8, cpuid)
+#define DMAMUX_INT_CH_BIT(chid, cpuid) \
+ (DMAMUX_INT_BIT(chid, cpuid) | DMAMUX_INTEN_BIT(cpuid))
+#define DMAMUX_INT_MASK(chid) \
+ (DMAMUX_INT_BIT(chid, 0) | \
+ DMAMUX_INT_BIT(chid, 1) | \
+ DMAMUX_INT_BIT(chid, 2))
+#define DMAMUX_INT_CH_MASK(chid, cpuid) \
+ (DMAMUX_INT_MASK(chid) | DMAMUX_INTEN_BIT(cpuid))
+
+struct cv1800_dmamux_data {
+ struct dma_router dmarouter;
+ struct regmap *regmap;
+ spinlock_t lock;
+ struct llist_head free_maps;
+ struct llist_head reserve_maps;
+ DECLARE_BITMAP(mapped_peripherals, MAX_DMA_MAPPING_ID);
+};
+
+struct cv1800_dmamux_map {
+ struct llist_node node;
+ unsigned int channel;
+ unsigned int peripheral;
+ unsigned int cpu;
+};
+
+static void cv1800_dmamux_free(struct device *dev, void *route_data)
+{
+ struct cv1800_dmamux_data *dmamux = dev_get_drvdata(dev);
+ struct cv1800_dmamux_map *map = route_data;
+
+ guard(spinlock_irqsave)(&dmamux->lock);
+
+ regmap_update_bits(dmamux->regmap,
+ DMAMUX_CH_REG(map->channel),
+ DMAMUX_CH_MASK(map->channel),
+ DMAMUX_CH_UPDATE_BIT);
+
+ regmap_update_bits(dmamux->regmap, REG_DMA_INT_MUX,
+ DMAMUX_INT_CH_MASK(map->channel, map->cpu),
+ DMAMUX_INTEN_BIT(map->cpu));
+
+ dev_dbg(dev, "free channel %u for req %u (cpu %u)\n",
+ map->channel, map->peripheral, map->cpu);
+}
+
+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, REG_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);
+}
+
+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_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ spin_lock_init(&data->lock);
+ init_llist_head(&data->free_maps);
+ init_llist_head(&data->reserve_maps);
+
+ 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);
+}
+
+static void cv1800_dmamux_remove(struct platform_device *pdev)
+{
+ of_dma_controller_free(pdev->dev.of_node);
+}
+
+static const struct of_device_id cv1800_dmamux_ids[] = {
+ { .compatible = "sophgo,cv1800b-dmamux", },
+ { }
+};
+MODULE_DEVICE_TABLE(of, cv1800_dmamux_ids);
+
+static struct platform_driver cv1800_dmamux_driver = {
+ .probe = cv1800_dmamux_probe,
+ .remove = cv1800_dmamux_remove,
+ .driver = {
+ .name = "cv1800-dmamux",
+ .of_match_table = cv1800_dmamux_ids,
+ },
+};
+module_platform_driver(cv1800_dmamux_driver);
+
+MODULE_AUTHOR("Inochi Amaoto <inochiama@gmail.com>");
+MODULE_DESCRIPTION("Sophgo CV1800/SG2000 Series SoC DMAMUX driver");
+MODULE_LICENSE("GPL");
projects / thirdparty / kernel / linux.git / commitdiff
