Add a driver that implements provisions to allow creationg of fake nvmem
devices and cells whose data comes from device tree blob.
Signed-off-by: Andrey Smirnov <andrew.smirnov@xxxxxxxxx>
---
drivers/misc/Makefile | 1 +
drivers/misc/nvmem-ro-of-blob.c | 196 ++++++++++++++++++++++++++++++++++++++++
2 files changed, 197 insertions(+)
create mode 100644 drivers/misc/nvmem-ro-of-blob.c
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index 94d2a4f..c7f56f8 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -6,3 +6,4 @@ obj-$(CONFIG_JTAG) += jtag.o
obj-$(CONFIG_SRAM) += sram.o
obj-$(CONFIG_STATE_DRV) += state.o
obj-y += mac-address-map.o
+obj-y += nvmem-ro-of-blob.o
diff --git a/drivers/misc/nvmem-ro-of-blob.c b/drivers/misc/nvmem-ro-of-blob.c
new file mode 100644
index 0000000..8a9f091
--- /dev/null
+++ b/drivers/misc/nvmem-ro-of-blob.c
@@ -0,0 +1,196 @@
+#include <common.h>
+#include <driver.h>
+#include <init.h>
+#include <malloc.h>
+#include <of.h>
+#include <state.h>
+#include <io.h>
+#include <fcntl.h>
+#include <net.h>
+#include <regmap.h>
+
+#include <linux/err.h>
+#include <linux/nvmem-provider.h>
+#include <linux/nvmem-consumer.h>
+
+struct nvmem_ro_of_blob_cell {
+ struct list_head node;
+
+ unsigned int start;
+ unsigned int end;
+ unsigned int size;
+
+ u8 *data;
+};
+
+struct nvmem_ro_of_blob {
+ struct regmap *map;
+ struct nvmem_config config;
+ struct nvmem_device *nvmem;
+ struct list_head cells;
+};
+
+struct nvmem_ro_of_blob_cell *
+nvmem_ro_of_blob_reg_to_cell(struct nvmem_ro_of_blob *nrob,
+ unsigned int reg)
+{
+ struct nvmem_ro_of_blob_cell *cell;
+
+ list_for_each_entry(cell, &nrob->cells, node) {
+ if (cell->start <= reg && reg <= cell->end)
+ return cell;
+ }
+
+ return NULL;
+}
+
+
+static int nvmem_ro_of_blob_reg_write(void *ctx, unsigned int reg,
+ unsigned int val)
+{
+ return -ENOTSUPP;
+}
+
+static int nvmem_ro_of_blob_reg_read(void *ctx, unsigned int reg,
+ unsigned int *val)
+{
+ struct nvmem_ro_of_blob *nrob = ctx;
+ struct nvmem_ro_of_blob_cell *cell =
+ nvmem_ro_of_blob_reg_to_cell(nrob, reg);
+
+ if (!cell)
+ return -ENOENT;
+
+ *val = cell->data[reg - cell->start];
+ return 0;
+}
+
+static const struct regmap_bus nvmem_ro_of_blob_regmap_bus = {
+ .reg_write = nvmem_ro_of_blob_reg_write,
+ .reg_read = nvmem_ro_of_blob_reg_read,
+};
+
+static const struct regmap_config nvmem_ro_of_blob_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .reg_stride = 1,
+ .max_register = 0xbc,
+};
+
+static int nvmem_ro_of_blob_validate_dt(struct device_node *np)
+{
+ /* struct device_node *child; */
+ /* for_each_child_of_node(np, child) { */
+ /* const __be32 *addr; */
+ /* int len; */
+
+ /* addr = of_get_property(child, "reg", &len); */
+ /* if (!addr) */
+ /* return -EINVAL; */
+
+ /* } */
+
+ return 0;
+}
+
+static int nvmem_ro_of_blob_probe(struct device_d *dev)
+{
+ int ret;
+ struct list_head *p, *n;
+ struct device_node *np = dev->device_node;
+ struct device_node *child;
+
+ struct nvmem_ro_of_blob *nrob;
+ struct nvmem_ro_of_blob_cell *cell;
+
+ BUG_ON(!np);
+
+ if (!of_get_next_child(np, NULL)) {
+ dev_dbg(dev, "Device node doesn't specify any cells\n");
+ return -EINVAL;
+ }
+
+ ret = nvmem_ro_of_blob_validate_dt(np);
+ if (ret < 0) {
+ dev_dbg(dev, "Device tree validation failed\n");
+ return ret;
+ }
+
+ nrob = xzalloc(sizeof(*nrob));
+ INIT_LIST_HEAD(&nrob->cells);
+
+ for_each_child_of_node(np, child) {
+ struct property *pp;
+ const __be32 *addr;
+ int len;
+
+ addr = of_get_property(child, "reg", &len);
+ BUG_ON(!addr);
+ cell = xzalloc(sizeof(*cell));
+
+ cell->start = be32_to_cpup(addr++);
+ cell->size = be32_to_cpup(addr);
+ cell->end = cell->start + cell->size - 1;
+
+ pp = of_find_property(child, "data", NULL);
+ BUG_ON(!pp || pp->length != cell->size);
+ cell->data = pp->value;
+
+ list_add_tail(&cell->node, &nrob->cells);
+ }
+
+ nrob->map = regmap_init(dev,
+ &nvmem_ro_of_blob_regmap_bus,
+ nrob,
+ &nvmem_ro_of_blob_regmap_config);
+ if (IS_ERR(nrob->map)) {
+ dev_dbg(dev, "Failed to initilize regmap\n");
+ ret = PTR_ERR(nrob->map);
+ goto free_resources;
+ }
+
+ nrob->config.name = "nvmem-ro-of-blob";
+ nrob->config.read_only = true;
+ nrob->config.dev = dev;
+
+ nrob->nvmem = nvmem_register(&nrob->config, nrob->map);
+ if (IS_ERR(nrob->nvmem)) {
+ dev_dbg(dev, "Filed to register nvmem device\n");
+ ret = PTR_ERR(nrob->nvmem);
+ goto free_resources;
+ }
+
+ dev_dbg(dev, "probed\n");
+ return 0;
+
+free_resources:
+ if (!IS_ERR_OR_NULL(nrob->map))
+ regmap_exit(nrob->map);
+
+ list_for_each_safe(p, n, &nrob->cells) {
+ cell = list_entry(p,
+ struct nvmem_ro_of_blob_cell,
+ node);
+ list_del(p);
+ free(cell->data);
+ free(cell);
+ }
+ free(nrob);
+
+ return ret;
+}
+
+static __maybe_unused struct of_device_id nvmem_ro_of_blob_ids[] = {
+ {
+ .compatible = "barebox,nvmem-ro-of-blob",
+ }, {
+ /* sentinel */
+ }
+};
+
+static struct driver_d nvmem_ro_of_blob_driver = {
+ .name = "nvmem-ro-of-blob",
+ .probe = nvmem_ro_of_blob_probe,
+ .of_compatible = DRV_OF_COMPAT(nvmem_ro_of_blob_ids),
+};
+device_platform_driver(nvmem_ro_of_blob_driver);
--
2.5.0
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