[PATCH] nvmem: Change to unified property interface

From: Kevin Paul Herbert
Date: Mon Mar 29 2021 - 18:40:08 EST

Change from using device tree (Open Firmware) APIs to the unified
'fwnode' interface.

Change of_nvmem_cell_get() to fwnode_nvmem_cell_get(), and add a
wrapper for of_nvmem_cell_get().

Change of_nvmem_device_get() to fwnode_nvmem_device_get(). There
are no known accessors to the OF interface, so no need for a wrapper.

Signed-off-by: Kevin Paul Herbert <kph@xxxxxxxxxxxxxxxxxx>
---
drivers/nvmem/core.c | 176 ++++++++++++++++++++-------------
include/linux/nvmem-consumer.h | 27 ++---
2 files changed, 123 insertions(+), 80 deletions(-)

diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index a5ab1e0c74cf..2e49304cd9a8 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -6,6 +6,7 @@
* Copyright (C) 2013 Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
*/

+#include <linux/acpi.h>
#include <linux/device.h>
#include <linux/export.h>
#include <linux/fs.h>
@@ -17,6 +18,7 @@
#include <linux/nvmem-provider.h>
#include <linux/gpio/consumer.h>
#include <linux/of.h>
+#include <linux/property.h>
#include <linux/slab.h>

struct nvmem_device {
@@ -52,7 +54,7 @@ struct nvmem_cell {
int bytes;
int bit_offset;
int nbits;
- struct device_node *np;
+ struct fwnode_handle *fwnode;
struct nvmem_device *nvmem;
struct list_head node;
};
@@ -424,7 +426,7 @@ static void nvmem_cell_drop(struct nvmem_cell *cell)
mutex_lock(&nvmem_mutex);
list_del(&cell->node);
mutex_unlock(&nvmem_mutex);
- of_node_put(cell->np);
+ fwnode_handle_put(cell->fwnode);
kfree_const(cell->name);
kfree(cell);
}
@@ -670,39 +672,40 @@ static int nvmem_validate_keepouts(struct nvmem_device *nvmem)
return 0;
}

-static int nvmem_add_cells_from_of(struct nvmem_device *nvmem)
+static int nvmem_add_cells_from_fw(struct nvmem_device *nvmem)
{
- struct device_node *parent, *child;
+ struct fwnode_handle *parent, *child;
struct device *dev = &nvmem->dev;
struct nvmem_cell *cell;
- const __be32 *addr;
- int len;
+ int rval;
+ u32 vals[2];

- parent = dev->of_node;
+ parent = dev_fwnode(dev);

- for_each_child_of_node(parent, child) {
- addr = of_get_property(child, "reg", &len);
- if (!addr)
+ fwnode_for_each_child_node(parent, child) {
+ rval = fwnode_property_read_u32_array(child, "reg", NULL, 2);
+ if (rval < 0)
continue;
- if (len < 2 * sizeof(u32)) {
- dev_err(dev, "nvmem: invalid reg on %pOF\n", child);
+ if (rval < 2) {
+ dev_err(dev, "nvmem: invalid reg %d on %pfw\n",
+ rval, child);
return -EINVAL;
}
-
+ rval = fwnode_property_read_u32_array(child, "reg", vals, 2);
cell = kzalloc(sizeof(*cell), GFP_KERNEL);
if (!cell)
return -ENOMEM;

cell->nvmem = nvmem;
- cell->np = of_node_get(child);
- cell->offset = be32_to_cpup(addr++);
- cell->bytes = be32_to_cpup(addr);
- cell->name = kasprintf(GFP_KERNEL, "%pOFn", child);
-
- addr = of_get_property(child, "bits", &len);
- if (addr && len == (2 * sizeof(u32))) {
- cell->bit_offset = be32_to_cpup(addr++);
- cell->nbits = be32_to_cpup(addr);
+ cell->fwnode = child;
+ cell->offset = vals[0];
+ cell->bytes = vals[1];
+ cell->name = kasprintf(GFP_KERNEL, "%pfwn", child);
+
+ rval = fwnode_property_read_u32_array(child, "bits", vals, 2);
+ if (rval >= 0) {
+ cell->bit_offset = vals[0];
+ cell->nbits = vals[1];
}

if (cell->nbits)
@@ -715,7 +718,7 @@ static int nvmem_add_cells_from_of(struct nvmem_device *nvmem)
cell->name, nvmem->stride);
/* Cells already added will be freed later. */
kfree_const(cell->name);
- of_node_put(cell->np);
+ fwnode_handle_put(cell->fwnode);
kfree(cell);
return -EINVAL;
}
@@ -789,8 +792,10 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
nvmem->reg_write = config->reg_write;
nvmem->keepout = config->keepout;
nvmem->nkeepout = config->nkeepout;
- if (!config->no_of_node)
+ if (!config->no_of_node) {
nvmem->dev.of_node = config->dev->of_node;
+ nvmem->dev.fwnode = config->dev->fwnode;
+ }

switch (config->id) {
case NVMEM_DEVID_NONE:
@@ -841,7 +846,7 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
if (rval)
goto err_remove_cells;

- rval = nvmem_add_cells_from_of(nvmem);
+ rval = nvmem_add_cells_from_fw(nvmem);
if (rval)
goto err_remove_cells;

@@ -984,36 +989,46 @@ static void __nvmem_device_put(struct nvmem_device *nvmem)
kref_put(&nvmem->refcnt, nvmem_device_release);
}

-#if IS_ENABLED(CONFIG_OF)
/**
- * of_nvmem_device_get() - Get nvmem device from a given id
+ * fwnode_nvmem_device_get() - Get nvmem device from a given id
*
- * @np: Device tree node that uses the nvmem device.
+ * @fwnode: Firmware node that uses the nvmem device.
* @id: nvmem name from nvmem-names property.
*
* Return: ERR_PTR() on error or a valid pointer to a struct nvmem_device
* on success.
*/
-struct nvmem_device *of_nvmem_device_get(struct device_node *np, const char *id)
+struct nvmem_device *fwnode_nvmem_device_get(struct fwnode_handle *fwnode, const char *id)
{
-
- struct device_node *nvmem_np;
+ struct fwnode_handle *nvmem_fwnode;
struct nvmem_device *nvmem;
int index = 0;

if (id)
- index = of_property_match_string(np, "nvmem-names", id);
-
- nvmem_np = of_parse_phandle(np, "nvmem", index);
- if (!nvmem_np)
- return ERR_PTR(-ENOENT);
+ index = fwnode_property_match_string(fwnode, "nvmem-names", id);
+
+ if (is_of_node(fwnode)) {
+ struct device_node *nvmem_np = of_parse_phandle(to_of_node(fwnode),
+ "nvmem", index);
+ if (!nvmem_np)
+ return ERR_PTR(-ENOENT);
+ nvmem_fwnode = &nvmem_np->fwnode;
+ } else if (is_acpi_device_node(fwnode)) {
+ struct fwnode_reference_args args;
+ int rval = acpi_node_get_property_reference(fwnode,
+ "nvmem", index, &args);
+ if (rval)
+ return ERR_PTR(rval);
+ nvmem_fwnode = args.fwnode;
+ } else {
+ return ERR_PTR(-ENXIO);
+ }

- nvmem = __nvmem_device_get(nvmem_np, device_match_of_node);
- of_node_put(nvmem_np);
+ nvmem = __nvmem_device_get(nvmem_fwnode, device_match_fwnode);
+ fwnode_handle_put(nvmem_fwnode);
return nvmem;
}
-EXPORT_SYMBOL_GPL(of_nvmem_device_get);
-#endif
+EXPORT_SYMBOL_GPL(fwnode_nvmem_device_get);

/**
* nvmem_device_get() - Get nvmem device from a given id
@@ -1026,16 +1041,15 @@ EXPORT_SYMBOL_GPL(of_nvmem_device_get);
*/
struct nvmem_device *nvmem_device_get(struct device *dev, const char *dev_name)
{
- if (dev->of_node) { /* try dt first */
- struct nvmem_device *nvmem;
+ struct fwnode_handle *fwnode = dev_fwnode(dev);

- nvmem = of_nvmem_device_get(dev->of_node, dev_name);
+ if (fwnode) { /* try firmware tree first */
+ struct nvmem_device *nvmem;

+ nvmem = fwnode_nvmem_device_get(fwnode, dev_name);
if (!IS_ERR(nvmem) || PTR_ERR(nvmem) == -EPROBE_DEFER)
return nvmem;
-
}
-
return __nvmem_device_get((void *)dev_name, device_match_name);
}
EXPORT_SYMBOL_GPL(nvmem_device_get);
@@ -1171,15 +1185,14 @@ nvmem_cell_get_from_lookup(struct device *dev, const char *con_id)
return cell;
}

-#if IS_ENABLED(CONFIG_OF)
static struct nvmem_cell *
-nvmem_find_cell_by_node(struct nvmem_device *nvmem, struct device_node *np)
+nvmem_find_cell_by_fwnode(struct nvmem_device *nvmem, struct fwnode_handle *fwnode)
{
struct nvmem_cell *iter, *cell = NULL;

mutex_lock(&nvmem_mutex);
list_for_each_entry(iter, &nvmem->cells, node) {
- if (np == iter->np) {
+ if (fwnode == iter->fwnode) {
cell = iter;
break;
}
@@ -1190,42 +1203,67 @@ nvmem_find_cell_by_node(struct nvmem_device *nvmem, struct device_node *np)
}

/**
- * of_nvmem_cell_get() - Get a nvmem cell from given device node and cell id
+ * fwnode_nvmem_cell_get() - Get a nvmem cell from given firmwar node and cell id
*
- * @np: Device tree node that uses the nvmem cell.
+ * @fwnode: Firmware node that uses the nvmem cell.
* @id: nvmem cell name from nvmem-cell-names property, or NULL
- * for the cell at index 0 (the lone cell with no accompanying
- * nvmem-cell-names property).
+ * for the cell at index 0 (the lone cell with no accompanying
+ * nvmem-cell-names property).
*
* Return: Will be an ERR_PTR() on error or a valid pointer
* to a struct nvmem_cell. The nvmem_cell will be freed by the
* nvmem_cell_put().
*/
-struct nvmem_cell *of_nvmem_cell_get(struct device_node *np, const char *id)
+struct nvmem_cell *fwnode_nvmem_cell_get(struct fwnode_handle *fwnode,
+ const char *id)
{
- struct device_node *cell_np, *nvmem_np;
+ struct fwnode_handle *nvmem_fwnode, *cell_fwnode;
struct nvmem_device *nvmem;
struct nvmem_cell *cell;
int index = 0;

/* if cell name exists, find index to the name */
- if (id)
- index = of_property_match_string(np, "nvmem-cell-names", id);
+ if (id) {
+ index = fwnode_property_match_string(fwnode, "nvmem-cell-names", id);
+ if (index < 0)
+ return ERR_PTR(index);
+ }

- cell_np = of_parse_phandle(np, "nvmem-cells", index);
- if (!cell_np)
- return ERR_PTR(-ENOENT);
+ if (is_of_node(fwnode)) {
+ struct device_node *np = to_of_node(fwnode);
+ struct device_node *cell_np = of_parse_phandle(np, "nvmem-cells", index);
+
+ if (!cell_np)
+ return ERR_PTR(-EINVAL);
+ cell_fwnode = &cell_np->fwnode;
+ } else if (is_acpi_device_node(fwnode)) {
+ struct fwnode_reference_args args;
+ struct fwnode_handle *dev_fwnode;
+ int rval;

- nvmem_np = of_get_next_parent(cell_np);
- if (!nvmem_np)
+ rval = acpi_node_get_property_reference(fwnode,
+ "nvmem-cells", index, &args);
+ if (rval)
+ return ERR_PTR(rval);
+ dev_fwnode = args.fwnode;
+ cell_fwnode = fwnode_get_named_child_node(dev_fwnode,
+ id ? id : "nvmem");
+ if (!cell_fwnode)
+ return ERR_PTR(-EINVAL);
+ } else {
+ return ERR_PTR(-ENXIO);
+ }
+
+ nvmem_fwnode = fwnode_get_next_parent(cell_fwnode);
+ if (!nvmem_fwnode)
return ERR_PTR(-EINVAL);

- nvmem = __nvmem_device_get(nvmem_np, device_match_of_node);
- of_node_put(nvmem_np);
+ nvmem = __nvmem_device_get(nvmem_fwnode, device_match_fwnode);
+ fwnode_handle_put(nvmem_fwnode);
if (IS_ERR(nvmem))
return ERR_CAST(nvmem);

- cell = nvmem_find_cell_by_node(nvmem, cell_np);
+ cell = nvmem_find_cell_by_fwnode(nvmem, cell_fwnode);
if (!cell) {
__nvmem_device_put(nvmem);
return ERR_PTR(-ENOENT);
@@ -1233,8 +1271,7 @@ struct nvmem_cell *of_nvmem_cell_get(struct device_node *np, const char *id)

return cell;
}
-EXPORT_SYMBOL_GPL(of_nvmem_cell_get);
-#endif
+EXPORT_SYMBOL_GPL(fwnode_nvmem_cell_get);

/**
* nvmem_cell_get() - Get nvmem cell of device form a given cell name
@@ -1251,14 +1288,15 @@ EXPORT_SYMBOL_GPL(of_nvmem_cell_get);
struct nvmem_cell *nvmem_cell_get(struct device *dev, const char *id)
{
struct nvmem_cell *cell;
+ struct fwnode_handle *fwnode = dev_fwnode(dev);

- if (dev->of_node) { /* try dt first */
- cell = of_nvmem_cell_get(dev->of_node, id);
+ if (fwnode) { /* try firmware tree first */
+ cell = fwnode_nvmem_cell_get(fwnode, id);
if (!IS_ERR(cell) || PTR_ERR(cell) == -EPROBE_DEFER)
return cell;
}

- /* NULL cell id only allowed for device tree; invalid otherwise */
+ /* NULL cell_id only allowed for firmware tree; invalid otherwise */
if (!id)
return ERR_PTR(-EINVAL);

diff --git a/include/linux/nvmem-consumer.h b/include/linux/nvmem-consumer.h
index 052293f4cbdb..e52c587d0a23 100644
--- a/include/linux/nvmem-consumer.h
+++ b/include/linux/nvmem-consumer.h
@@ -12,12 +12,14 @@
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/notifier.h>
+#include <linux/of.h>

struct device;
struct device_node;
/* consumer cookie */
struct nvmem_cell;
struct nvmem_device;
+struct fwnode_handle;

struct nvmem_cell_info {
const char *name;
@@ -94,6 +96,10 @@ int nvmem_unregister_notifier(struct notifier_block *nb);
struct nvmem_device *nvmem_device_find(void *data,
int (*match)(struct device *dev, const void *data));

+struct nvmem_cell *fwnode_nvmem_cell_get(struct fwnode_handle *np,
+ const char *name);
+struct nvmem_device *fwnode_nvmem_device_get(struct fwnode_handle *np,
+ const char *name);
#else

static inline struct nvmem_cell *nvmem_cell_get(struct device *dev,
@@ -221,25 +227,24 @@ static inline struct nvmem_device *nvmem_device_find(void *data,
return NULL;
}

-#endif /* CONFIG_NVMEM */
+static inline struct nvmem_cell *fwnode_nvmem_cell_get(struct fwnode_handle *np,
+ const char *name)
+{
+ return ERR_PTR(-EOPNOTSUPP);
+}

-#if IS_ENABLED(CONFIG_NVMEM) && IS_ENABLED(CONFIG_OF)
-struct nvmem_cell *of_nvmem_cell_get(struct device_node *np,
- const char *id);
-struct nvmem_device *of_nvmem_device_get(struct device_node *np,
- const char *name);
-#else
-static inline struct nvmem_cell *of_nvmem_cell_get(struct device_node *np,
- const char *id)
+static inline struct nvmem_device *fwnode_nvmem_device_get(struct fwnode_handle *np,
+ const char *name)
{
return ERR_PTR(-EOPNOTSUPP);
}

+#endif /* CONFIG_NVMEM */
+
static inline struct nvmem_device *of_nvmem_device_get(struct device_node *np,
const char *name)
{
- return ERR_PTR(-EOPNOTSUPP);
+ return np ? fwnode_nvmem_device_get(&np->fwnode, name) : NULL;
}
-#endif /* CONFIG_NVMEM && CONFIG_OF */

#endif /* ifndef _LINUX_NVMEM_CONSUMER_H */
--
2.25.1