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authorLinus Torvalds <torvalds@linux-foundation.org>2023-04-27 12:07:50 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2023-04-27 12:07:50 -0700
commitcec24b8b6bb841a19b5c5555b600a511a8988100 (patch)
treeb12115ba8e6e6929cea0658ee3c9dae9aad8a82d /drivers/nvmem/core.c
parent556eb8b79190151506187bf0b16dda423c34d9a8 (diff)
parent2025b2ca8004c04861903d076c67a73a0ec6dfca (diff)
downloadlwn-cec24b8b6bb841a19b5c5555b600a511a8988100.tar.gz
lwn-cec24b8b6bb841a19b5c5555b600a511a8988100.zip
Merge tag 'char-misc-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc drivers updates from Greg KH: "Here is the "big" set of char/misc and other driver subsystems for 6.4-rc1. It's pretty big, but due to the removal of pcmcia drivers, almost breaks even for number of lines added vs. removed, a nice change. Included in here are: - removal of unused PCMCIA drivers (finally!) - Interconnect driver updates and additions - Lots of IIO driver updates and additions - MHI driver updates - Coresight driver updates - NVMEM driver updates, which required some OF updates - W1 driver updates and a new maintainer to manage the subsystem - FPGA driver updates - New driver subsystem, CDX, for AMD systems - lots of other small driver updates and additions All of these have been in linux-next for a while with no reported issues" * tag 'char-misc-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (196 commits) mcb-lpc: Reallocate memory region to avoid memory overlapping mcb-pci: Reallocate memory region to avoid memory overlapping mcb: Return actual parsed size when reading chameleon table kernel/configs: Drop Android config fragments virt: acrn: Replace obsolete memalign() with posix_memalign() spmi: Add a check for remove callback when removing a SPMI driver spmi: fix W=1 kernel-doc warnings spmi: mtk-pmif: Drop of_match_ptr for ID table spmi: pmic-arb: Convert to platform remove callback returning void spmi: mtk-pmif: Convert to platform remove callback returning void spmi: hisi-spmi-controller: Convert to platform remove callback returning void w1: gpio: remove unnecessary ENOMEM messages w1: omap-hdq: remove unnecessary ENOMEM messages w1: omap-hdq: add SPDX tag w1: omap-hdq: allow compile testing w1: matrox: remove unnecessary ENOMEM messages w1: matrox: use inline over __inline__ w1: matrox: switch from asm to linux header w1: ds2482: do not use assignment in if condition w1: ds2482: drop unnecessary header ...
Diffstat (limited to 'drivers/nvmem/core.c')
-rw-r--r--drivers/nvmem/core.c169
1 files changed, 161 insertions, 8 deletions
diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index 22024b830788..a62973d010ff 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -17,6 +17,7 @@
#include <linux/nvmem-provider.h>
#include <linux/gpio/consumer.h>
#include <linux/of.h>
+#include <linux/of_device.h>
#include <linux/slab.h>
struct nvmem_device {
@@ -38,8 +39,8 @@ struct nvmem_device {
unsigned int nkeepout;
nvmem_reg_read_t reg_read;
nvmem_reg_write_t reg_write;
- nvmem_cell_post_process_t cell_post_process;
struct gpio_desc *wp_gpio;
+ struct nvmem_layout *layout;
void *priv;
};
@@ -49,9 +50,12 @@ struct nvmem_device {
struct nvmem_cell_entry {
const char *name;
int offset;
+ size_t raw_len;
int bytes;
int bit_offset;
int nbits;
+ nvmem_cell_post_process_t read_post_process;
+ void *priv;
struct device_node *np;
struct nvmem_device *nvmem;
struct list_head node;
@@ -74,6 +78,9 @@ static LIST_HEAD(nvmem_lookup_list);
static BLOCKING_NOTIFIER_HEAD(nvmem_notifier);
+static DEFINE_SPINLOCK(nvmem_layout_lock);
+static LIST_HEAD(nvmem_layouts);
+
static int __nvmem_reg_read(struct nvmem_device *nvmem, unsigned int offset,
void *val, size_t bytes)
{
@@ -463,8 +470,11 @@ static int nvmem_cell_info_to_nvmem_cell_entry_nodup(struct nvmem_device *nvmem,
{
cell->nvmem = nvmem;
cell->offset = info->offset;
+ cell->raw_len = info->raw_len ?: info->bytes;
cell->bytes = info->bytes;
cell->name = info->name;
+ cell->read_post_process = info->read_post_process;
+ cell->priv = info->priv;
cell->bit_offset = info->bit_offset;
cell->nbits = info->nbits;
@@ -688,6 +698,7 @@ static int nvmem_validate_keepouts(struct nvmem_device *nvmem)
static int nvmem_add_cells_from_of(struct nvmem_device *nvmem)
{
+ struct nvmem_layout *layout = nvmem->layout;
struct device *dev = &nvmem->dev;
struct device_node *child;
const __be32 *addr;
@@ -717,6 +728,9 @@ static int nvmem_add_cells_from_of(struct nvmem_device *nvmem)
info.np = of_node_get(child);
+ if (layout && layout->fixup_cell_info)
+ layout->fixup_cell_info(nvmem, layout, &info);
+
ret = nvmem_add_one_cell(nvmem, &info);
kfree(info.name);
if (ret) {
@@ -728,6 +742,108 @@ static int nvmem_add_cells_from_of(struct nvmem_device *nvmem)
return 0;
}
+int __nvmem_layout_register(struct nvmem_layout *layout, struct module *owner)
+{
+ layout->owner = owner;
+
+ spin_lock(&nvmem_layout_lock);
+ list_add(&layout->node, &nvmem_layouts);
+ spin_unlock(&nvmem_layout_lock);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(__nvmem_layout_register);
+
+void nvmem_layout_unregister(struct nvmem_layout *layout)
+{
+ spin_lock(&nvmem_layout_lock);
+ list_del(&layout->node);
+ spin_unlock(&nvmem_layout_lock);
+}
+EXPORT_SYMBOL_GPL(nvmem_layout_unregister);
+
+static struct nvmem_layout *nvmem_layout_get(struct nvmem_device *nvmem)
+{
+ struct device_node *layout_np, *np = nvmem->dev.of_node;
+ struct nvmem_layout *l, *layout = ERR_PTR(-EPROBE_DEFER);
+
+ layout_np = of_get_child_by_name(np, "nvmem-layout");
+ if (!layout_np)
+ return NULL;
+
+ /*
+ * In case the nvmem device was built-in while the layout was built as a
+ * module, we shall manually request the layout driver loading otherwise
+ * we'll never have any match.
+ */
+ of_request_module(layout_np);
+
+ spin_lock(&nvmem_layout_lock);
+
+ list_for_each_entry(l, &nvmem_layouts, node) {
+ if (of_match_node(l->of_match_table, layout_np)) {
+ if (try_module_get(l->owner))
+ layout = l;
+
+ break;
+ }
+ }
+
+ spin_unlock(&nvmem_layout_lock);
+ of_node_put(layout_np);
+
+ return layout;
+}
+
+static void nvmem_layout_put(struct nvmem_layout *layout)
+{
+ if (layout)
+ module_put(layout->owner);
+}
+
+static int nvmem_add_cells_from_layout(struct nvmem_device *nvmem)
+{
+ struct nvmem_layout *layout = nvmem->layout;
+ int ret;
+
+ if (layout && layout->add_cells) {
+ ret = layout->add_cells(&nvmem->dev, nvmem, layout);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+#if IS_ENABLED(CONFIG_OF)
+/**
+ * of_nvmem_layout_get_container() - Get OF node to layout container.
+ *
+ * @nvmem: nvmem device.
+ *
+ * Return: a node pointer with refcount incremented or NULL if no
+ * container exists. Use of_node_put() on it when done.
+ */
+struct device_node *of_nvmem_layout_get_container(struct nvmem_device *nvmem)
+{
+ return of_get_child_by_name(nvmem->dev.of_node, "nvmem-layout");
+}
+EXPORT_SYMBOL_GPL(of_nvmem_layout_get_container);
+#endif
+
+const void *nvmem_layout_get_match_data(struct nvmem_device *nvmem,
+ struct nvmem_layout *layout)
+{
+ struct device_node __maybe_unused *layout_np;
+ const struct of_device_id *match;
+
+ layout_np = of_nvmem_layout_get_container(nvmem);
+ match = of_match_node(layout->of_match_table, layout_np);
+
+ return match ? match->data : NULL;
+}
+EXPORT_SYMBOL_GPL(nvmem_layout_get_match_data);
+
/**
* nvmem_register() - Register a nvmem device for given nvmem_config.
* Also creates a binary entry in /sys/bus/nvmem/devices/dev-name/nvmem
@@ -790,7 +906,6 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
nvmem->type = config->type;
nvmem->reg_read = config->reg_read;
nvmem->reg_write = config->reg_write;
- nvmem->cell_post_process = config->cell_post_process;
nvmem->keepout = config->keepout;
nvmem->nkeepout = config->nkeepout;
if (config->of_node)
@@ -834,6 +949,19 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
goto err_put_device;
}
+ /*
+ * If the driver supplied a layout by config->layout, the module
+ * pointer will be NULL and nvmem_layout_put() will be a noop.
+ */
+ nvmem->layout = config->layout ?: nvmem_layout_get(nvmem);
+ if (IS_ERR(nvmem->layout)) {
+ rval = PTR_ERR(nvmem->layout);
+ nvmem->layout = NULL;
+
+ if (rval == -EPROBE_DEFER)
+ goto err_teardown_compat;
+ }
+
if (config->cells) {
rval = nvmem_add_cells(nvmem, config->cells, config->ncells);
if (rval)
@@ -854,12 +982,18 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
if (rval)
goto err_remove_cells;
+ rval = nvmem_add_cells_from_layout(nvmem);
+ if (rval)
+ goto err_remove_cells;
+
blocking_notifier_call_chain(&nvmem_notifier, NVMEM_ADD, nvmem);
return nvmem;
err_remove_cells:
nvmem_device_remove_all_cells(nvmem);
+ nvmem_layout_put(nvmem->layout);
+err_teardown_compat:
if (config->compat)
nvmem_sysfs_remove_compat(nvmem, config);
err_put_device:
@@ -881,6 +1015,7 @@ static void nvmem_device_release(struct kref *kref)
device_remove_bin_file(nvmem->base_dev, &nvmem->eeprom);
nvmem_device_remove_all_cells(nvmem);
+ nvmem_layout_put(nvmem->layout);
device_unregister(&nvmem->dev);
}
@@ -1246,6 +1381,15 @@ struct nvmem_cell *of_nvmem_cell_get(struct device_node *np, const char *id)
return ERR_PTR(-EINVAL);
}
+ /* nvmem layouts produce cells within the nvmem-layout container */
+ if (of_node_name_eq(nvmem_np, "nvmem-layout")) {
+ nvmem_np = of_get_next_parent(nvmem_np);
+ if (!nvmem_np) {
+ of_node_put(cell_np);
+ return ERR_PTR(-EINVAL);
+ }
+ }
+
nvmem = __nvmem_device_get(nvmem_np, device_match_of_node);
of_node_put(nvmem_np);
if (IS_ERR(nvmem)) {
@@ -1418,7 +1562,7 @@ static int __nvmem_cell_read(struct nvmem_device *nvmem,
{
int rc;
- rc = nvmem_reg_read(nvmem, cell->offset, buf, cell->bytes);
+ rc = nvmem_reg_read(nvmem, cell->offset, buf, cell->raw_len);
if (rc)
return rc;
@@ -1427,9 +1571,9 @@ static int __nvmem_cell_read(struct nvmem_device *nvmem,
if (cell->bit_offset || cell->nbits)
nvmem_shift_read_buffer_in_place(cell, buf);
- if (nvmem->cell_post_process) {
- rc = nvmem->cell_post_process(nvmem->priv, id, index,
- cell->offset, buf, cell->bytes);
+ if (cell->read_post_process) {
+ rc = cell->read_post_process(cell->priv, id, index,
+ cell->offset, buf, cell->raw_len);
if (rc)
return rc;
}
@@ -1452,14 +1596,15 @@ static int __nvmem_cell_read(struct nvmem_device *nvmem,
*/
void *nvmem_cell_read(struct nvmem_cell *cell, size_t *len)
{
- struct nvmem_device *nvmem = cell->entry->nvmem;
+ struct nvmem_cell_entry *entry = cell->entry;
+ struct nvmem_device *nvmem = entry->nvmem;
u8 *buf;
int rc;
if (!nvmem)
return ERR_PTR(-EINVAL);
- buf = kzalloc(cell->entry->bytes, GFP_KERNEL);
+ buf = kzalloc(max_t(size_t, entry->raw_len, entry->bytes), GFP_KERNEL);
if (!buf)
return ERR_PTR(-ENOMEM);
@@ -1535,6 +1680,14 @@ static int __nvmem_cell_entry_write(struct nvmem_cell_entry *cell, void *buf, si
(cell->bit_offset == 0 && len != cell->bytes))
return -EINVAL;
+ /*
+ * Any cells which have a read_post_process hook are read-only because
+ * we cannot reverse the operation and it might affect other cells,
+ * too.
+ */
+ if (cell->read_post_process)
+ return -EINVAL;
+
if (cell->bit_offset || cell->nbits) {
buf = nvmem_cell_prepare_write_buffer(cell, buf, len);
if (IS_ERR(buf))