[PATCH v4 1/4] drivers: add nvmem framework from kernel
Oleksij Rempel
o.rempel at pengutronix.de
Mon Mar 27 08:17:38 PDT 2017
From: Steffen Trumtrar <s.trumtrar at pengutronix.de>
Add the nvmem framework from Linux.
Based on the v4.4-rc3 version.
Signed-off-by: Steffen Trumtrar <s.trumtrar at pengutronix.de>
Signed-off-by: Oleksij Rempel <o.rempel at pengutronix.de>
---
drivers/Kconfig | 1 +
drivers/Makefile | 1 +
drivers/nvmem/Kconfig | 8 +
drivers/nvmem/Makefile | 6 +
drivers/nvmem/core.c | 764 +++++++++++++++++++++++++++++++++++++++++
include/linux/nvmem-consumer.h | 94 +++++
include/linux/nvmem-provider.h | 49 +++
7 files changed, 923 insertions(+)
create mode 100644 drivers/nvmem/Kconfig
create mode 100644 drivers/nvmem/Makefile
create mode 100644 drivers/nvmem/core.c
create mode 100644 include/linux/nvmem-consumer.h
create mode 100644 include/linux/nvmem-provider.h
diff --git a/drivers/Kconfig b/drivers/Kconfig
index cc086ac2d..9b0daa711 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -25,6 +25,7 @@ source "drivers/dma/Kconfig"
source "drivers/gpio/Kconfig"
source "drivers/w1/Kconfig"
source "drivers/pinctrl/Kconfig"
+source "drivers/nvmem/Kconfig"
source "drivers/bus/Kconfig"
source "drivers/regulator/Kconfig"
source "drivers/reset/Kconfig"
diff --git a/drivers/Makefile b/drivers/Makefile
index 6a70f6ee1..cb198e01a 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -17,6 +17,7 @@ obj-y += eeprom/
obj-$(CONFIG_PWM) += pwm/
obj-y += input/
obj-y += misc/
+obj-$(CONFIG_NVMEM) += nvmem/
obj-y += dma/
obj-y += watchdog/
obj-y += gpio/
diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
new file mode 100644
index 000000000..218be05b2
--- /dev/null
+++ b/drivers/nvmem/Kconfig
@@ -0,0 +1,8 @@
+menuconfig NVMEM
+ bool "NVMEM Support"
+ help
+ Support for NVMEM(Non Volatile Memory) devices like EEPROM, EFUSES...
+
+ This framework is designed to provide a generic interface to NVMEM
+
+ If unsure, say no.
diff --git a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile
new file mode 100644
index 000000000..6df2c6952
--- /dev/null
+++ b/drivers/nvmem/Makefile
@@ -0,0 +1,6 @@
+#
+# Makefile for nvmem drivers.
+#
+
+obj-$(CONFIG_NVMEM) += nvmem_core.o
+nvmem_core-y := core.o
diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
new file mode 100644
index 000000000..4e50a8843
--- /dev/null
+++ b/drivers/nvmem/core.c
@@ -0,0 +1,764 @@
+/*
+ * nvmem framework core.
+ *
+ * Copyright (C) 2015 Srinivas Kandagatla <srinivas.kandagatla at linaro.org>
+ * Copyright (C) 2013 Maxime Ripard <maxime.ripard at free-electrons.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <common.h>
+#include <libbb.h>
+#include <malloc.h>
+#include <of.h>
+#include <linux/nvmem-consumer.h>
+#include <linux/nvmem-provider.h>
+
+struct nvmem_device {
+ const char *name;
+ struct device_d dev;
+ const struct nvmem_bus *bus;
+ struct list_head node;
+ int stride;
+ int word_size;
+ int ncells;
+ int users;
+ size_t size;
+ bool read_only;
+ struct cdev cdev;
+};
+
+struct nvmem_cell {
+ const char *name;
+ int offset;
+ int bytes;
+ int bit_offset;
+ int nbits;
+ struct nvmem_device *nvmem;
+ struct list_head node;
+};
+
+static LIST_HEAD(nvmem_cells);
+static LIST_HEAD(nvmem_devs);
+
+int nvmem_device_read(struct nvmem_device *nvmem, unsigned int offset,
+ size_t bytes, void *buf);
+int nvmem_device_write(struct nvmem_device *nvmem, unsigned int offset,
+ size_t bytes, const void *buf);
+
+
+static ssize_t nvmem_cdev_read(struct cdev *cdev, void *buf, size_t count,
+ loff_t offset, unsigned long flags)
+{
+ struct nvmem_device *nvmem = container_of(cdev, struct nvmem_device, cdev);
+ ssize_t retlen;
+
+ dev_dbg(cdev->dev, "read ofs: 0x%08llx count: 0x%08zx\n",
+ offset, count);
+
+ retlen = nvmem_device_read(nvmem, offset, count, buf);
+
+ return retlen;
+}
+
+static ssize_t nvmem_cdev_write(struct cdev *cdev, const void *buf, size_t count,
+ loff_t offset, unsigned long flags)
+{
+ struct nvmem_device *nvmem = container_of(cdev, struct nvmem_device, cdev);
+ ssize_t retlen;
+
+ dev_dbg(cdev->dev, "write ofs: 0x%08llx count: 0x%08zx\n",
+ offset, count);
+
+ retlen = nvmem_device_write(nvmem, offset, count, buf);
+
+ return retlen;
+}
+
+static struct file_operations nvmem_chrdev_ops = {
+ .read = nvmem_cdev_read,
+ .write = nvmem_cdev_write,
+ .lseek = dev_lseek_default,
+};
+
+static int nvmem_register_cdev(struct nvmem_device *nvmem)
+{
+ struct device_d *dev = &nvmem->dev;
+ const char *alias;
+ char *devname;
+ int err;
+
+ alias = of_alias_get(dev->device_node);
+ if (alias) {
+ devname = xstrdup(alias);
+ } else {
+ err = cdev_find_free_index("nvmem");
+ if (err < 0) {
+ dev_err(dev, "no index found to name device\n");
+ return err;
+ }
+ devname = xasprintf("nvmem%d", err);
+ }
+
+ nvmem->cdev.name = devname;
+ nvmem->cdev.flags = DEVFS_IS_CHARACTER_DEV;
+ nvmem->cdev.ops = &nvmem_chrdev_ops;
+ nvmem->cdev.dev = &nvmem->dev;
+ nvmem->cdev.size = nvmem->size;
+
+ return devfs_create(&nvmem->cdev);
+}
+
+static struct nvmem_device *of_nvmem_find(struct device_node *nvmem_np)
+{
+ struct nvmem_device *dev;
+
+ if (!nvmem_np)
+ return NULL;
+
+ list_for_each_entry(dev, &nvmem_devs, node)
+ if (dev->dev.device_node->name && !strcmp(dev->dev.device_node->name, nvmem_np->name))
+ return dev;
+
+ return NULL;
+}
+
+static struct nvmem_cell *nvmem_find_cell(const char *cell_id)
+{
+ struct nvmem_cell *p;
+
+ list_for_each_entry(p, &nvmem_cells, node)
+ if (p && !strcmp(p->name, cell_id))
+ return p;
+
+ return NULL;
+}
+
+static void nvmem_cell_drop(struct nvmem_cell *cell)
+{
+ list_del(&cell->node);
+ kfree(cell);
+}
+
+static void nvmem_cell_add(struct nvmem_cell *cell)
+{
+ list_add_tail(&cell->node, &nvmem_cells);
+}
+
+static int nvmem_cell_info_to_nvmem_cell(struct nvmem_device *nvmem,
+ const struct nvmem_cell_info *info,
+ struct nvmem_cell *cell)
+{
+ cell->nvmem = nvmem;
+ cell->offset = info->offset;
+ cell->bytes = info->bytes;
+ cell->name = info->name;
+
+ cell->bit_offset = info->bit_offset;
+ cell->nbits = info->nbits;
+
+ if (cell->nbits)
+ cell->bytes = DIV_ROUND_UP(cell->nbits + cell->bit_offset,
+ BITS_PER_BYTE);
+
+ if (!IS_ALIGNED(cell->offset, nvmem->stride)) {
+ dev_err(&nvmem->dev,
+ "cell %s unaligned to nvmem stride %d\n",
+ cell->name, nvmem->stride);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+/**
+ * nvmem_register() - Register a nvmem device for given nvmem_config.
+ *
+ * @config: nvmem device configuration with which nvmem device is created.
+ *
+ * Return: Will be an ERR_PTR() on error or a valid pointer to nvmem_device
+ * on success.
+ */
+
+struct nvmem_device *nvmem_register(const struct nvmem_config *config)
+{
+ struct nvmem_device *nvmem;
+ struct device_node *np;
+ int rval;
+
+ if (!config->dev)
+ return ERR_PTR(-EINVAL);
+
+ nvmem = kzalloc(sizeof(*nvmem), GFP_KERNEL);
+ if (!nvmem)
+ return ERR_PTR(-ENOMEM);
+
+ nvmem->stride = config->stride;
+ nvmem->word_size = config->word_size;
+ nvmem->size = config->size;
+ nvmem->dev.parent = config->dev;
+ nvmem->bus = config->bus;
+ np = config->dev->device_node;
+ nvmem->dev.device_node = np;
+
+ nvmem->read_only = of_property_read_bool(np, "read-only") |
+ config->read_only;
+
+ safe_strncpy(nvmem->dev.name, config->name, MAX_DRIVER_NAME);
+ nvmem->dev.id = DEVICE_ID_DYNAMIC;
+
+ dev_dbg(&nvmem->dev, "Registering nvmem device %s\n", config->name);
+
+ rval = register_device(&nvmem->dev);
+ if (rval) {
+ kfree(nvmem);
+ return ERR_PTR(rval);
+ }
+
+ rval = nvmem_register_cdev(nvmem);
+ if (rval) {
+ kfree(nvmem);
+ return ERR_PTR(rval);
+ }
+
+ list_add_tail(&nvmem->node, &nvmem_devs);
+
+ return nvmem;
+}
+EXPORT_SYMBOL_GPL(nvmem_register);
+
+static struct nvmem_device *__nvmem_device_get(struct device_node *np,
+ struct nvmem_cell **cellp,
+ const char *cell_id)
+{
+ struct nvmem_device *nvmem = NULL;
+
+ if (np) {
+ nvmem = of_nvmem_find(np);
+ if (!nvmem)
+ return ERR_PTR(-EPROBE_DEFER);
+ } else {
+ struct nvmem_cell *cell = nvmem_find_cell(cell_id);
+
+ if (cell) {
+ nvmem = cell->nvmem;
+ *cellp = cell;
+ }
+
+ if (!nvmem)
+ return ERR_PTR(-ENOENT);
+ }
+
+ nvmem->users++;
+
+ return nvmem;
+}
+
+static void __nvmem_device_put(struct nvmem_device *nvmem)
+{
+ nvmem->users--;
+}
+
+static struct nvmem_device *nvmem_find(const char *name)
+{
+ return ERR_PTR(-ENOSYS);
+}
+
+#if IS_ENABLED(CONFIG_NVMEM) && IS_ENABLED(CONFIG_OFTREE)
+/**
+ * of_nvmem_device_get() - Get nvmem device from a given id
+ *
+ * @dev node: Device tree 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 device_node *nvmem_np;
+ int index;
+
+ index = of_property_match_string(np, "nvmem-names", id);
+
+ nvmem_np = of_parse_phandle(np, "nvmem", index);
+ if (!nvmem_np)
+ return ERR_PTR(-EINVAL);
+
+ return __nvmem_device_get(nvmem_np, NULL, NULL);
+}
+EXPORT_SYMBOL_GPL(of_nvmem_device_get);
+#endif
+
+/**
+ * nvmem_device_get() - Get nvmem device from a given id
+ *
+ * @dev : Device 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 *nvmem_device_get(struct device_d *dev, const char *dev_name)
+{
+ if (dev->device_node) { /* try dt first */
+ struct nvmem_device *nvmem;
+
+ nvmem = of_nvmem_device_get(dev->device_node, dev_name);
+
+ if (!IS_ERR(nvmem) || PTR_ERR(nvmem) == -EPROBE_DEFER)
+ return nvmem;
+
+ }
+
+ return nvmem_find(dev_name);
+}
+EXPORT_SYMBOL_GPL(nvmem_device_get);
+
+/**
+ * nvmem_device_put() - put alredy got nvmem device
+ *
+ * @nvmem: pointer to nvmem device that needs to be released.
+ */
+void nvmem_device_put(struct nvmem_device *nvmem)
+{
+ __nvmem_device_put(nvmem);
+}
+EXPORT_SYMBOL_GPL(nvmem_device_put);
+
+static struct nvmem_cell *nvmem_cell_get_from_list(const char *cell_id)
+{
+ struct nvmem_cell *cell = NULL;
+ struct nvmem_device *nvmem;
+
+ nvmem = __nvmem_device_get(NULL, &cell, cell_id);
+ if (IS_ERR(nvmem))
+ return ERR_CAST(nvmem);
+
+ return cell;
+}
+
+#if IS_ENABLED(CONFIG_NVMEM) && IS_ENABLED(CONFIG_OFTREE)
+/**
+ * of_nvmem_cell_get() - Get a nvmem cell from given device node and cell id
+ *
+ * @dev node: Device tree node that uses the nvmem cell
+ * @id: nvmem cell name from 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 *name)
+{
+ struct device_node *cell_np, *nvmem_np;
+ struct nvmem_cell *cell;
+ struct nvmem_device *nvmem;
+ const __be32 *addr;
+ int rval, len, index;
+
+ index = of_property_match_string(np, "nvmem-cell-names", name);
+
+ cell_np = of_parse_phandle(np, "nvmem-cells", index);
+ if (!cell_np)
+ return ERR_PTR(-EINVAL);
+
+ nvmem_np = of_get_parent(cell_np);
+ if (!nvmem_np)
+ return ERR_PTR(-EINVAL);
+
+ nvmem = __nvmem_device_get(nvmem_np, NULL, NULL);
+ if (IS_ERR(nvmem))
+ return ERR_CAST(nvmem);
+
+ addr = of_get_property(cell_np, "reg", &len);
+ if (!addr || (len < 2 * sizeof(u32))) {
+ dev_err(&nvmem->dev, "nvmem: invalid reg on %s\n",
+ cell_np->full_name);
+ rval = -EINVAL;
+ goto err_mem;
+ }
+
+ cell = kzalloc(sizeof(*cell), GFP_KERNEL);
+ if (!cell) {
+ rval = -ENOMEM;
+ goto err_mem;
+ }
+
+ cell->nvmem = nvmem;
+ cell->offset = be32_to_cpup(addr++);
+ cell->bytes = be32_to_cpup(addr);
+ cell->name = cell_np->name;
+
+ addr = of_get_property(cell_np, "bits", &len);
+ if (addr && len == (2 * sizeof(u32))) {
+ cell->bit_offset = be32_to_cpup(addr++);
+ cell->nbits = be32_to_cpup(addr);
+ }
+
+ if (cell->nbits)
+ cell->bytes = DIV_ROUND_UP(cell->nbits + cell->bit_offset,
+ BITS_PER_BYTE);
+
+ if (cell->bytes < nvmem->word_size)
+ cell->bytes = nvmem->word_size;
+
+ if (!IS_ALIGNED(cell->offset, nvmem->stride)) {
+ dev_err(&nvmem->dev,
+ "cell %s unaligned to nvmem stride %d\n",
+ cell->name, nvmem->stride);
+ rval = -EINVAL;
+ goto err_sanity;
+ }
+
+ nvmem_cell_add(cell);
+
+ return cell;
+
+err_sanity:
+ kfree(cell);
+
+err_mem:
+ __nvmem_device_put(nvmem);
+
+ return ERR_PTR(rval);
+}
+EXPORT_SYMBOL_GPL(of_nvmem_cell_get);
+#endif
+
+/**
+ * nvmem_cell_get() - Get nvmem cell of device form a given cell name
+ *
+ * @dev node: Device tree node that uses the nvmem cell
+ * @id: nvmem cell name to get.
+ *
+ * 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 *nvmem_cell_get(struct device_d *dev, const char *cell_id)
+{
+ struct nvmem_cell *cell;
+
+ if (dev->device_node) { /* try dt first */
+ cell = of_nvmem_cell_get(dev->device_node, cell_id);
+ if (!IS_ERR(cell) || PTR_ERR(cell) == -EPROBE_DEFER)
+ return cell;
+ }
+
+ return nvmem_cell_get_from_list(cell_id);
+}
+EXPORT_SYMBOL_GPL(nvmem_cell_get);
+
+/**
+ * nvmem_cell_put() - Release previously allocated nvmem cell.
+ *
+ * @cell: Previously allocated nvmem cell by nvmem_cell_get()
+ */
+void nvmem_cell_put(struct nvmem_cell *cell)
+{
+ struct nvmem_device *nvmem = cell->nvmem;
+
+ __nvmem_device_put(nvmem);
+ nvmem_cell_drop(cell);
+}
+EXPORT_SYMBOL_GPL(nvmem_cell_put);
+
+static inline void nvmem_shift_read_buffer_in_place(struct nvmem_cell *cell,
+ void *buf)
+{
+ u8 *p, *b;
+ int i, bit_offset = cell->bit_offset;
+
+ p = b = buf;
+ if (bit_offset) {
+ /* First shift */
+ *b++ >>= bit_offset;
+
+ /* setup rest of the bytes if any */
+ for (i = 1; i < cell->bytes; i++) {
+ /* Get bits from next byte and shift them towards msb */
+ *p |= *b << (BITS_PER_BYTE - bit_offset);
+
+ p = b;
+ *b++ >>= bit_offset;
+ }
+
+ /* result fits in less bytes */
+ if (cell->bytes != DIV_ROUND_UP(cell->nbits, BITS_PER_BYTE))
+ *p-- = 0;
+ }
+ /* clear msb bits if any leftover in the last byte */
+ *p &= GENMASK((cell->nbits%BITS_PER_BYTE) - 1, 0);
+}
+
+static int __nvmem_cell_read(struct nvmem_device *nvmem,
+ struct nvmem_cell *cell,
+ void *buf, size_t *len)
+{
+ int rc;
+
+ rc = nvmem->bus->read(&nvmem->dev, cell->offset, buf, cell->bytes);
+ if (IS_ERR_VALUE(rc))
+ return rc;
+
+ /* shift bits in-place */
+ if (cell->bit_offset || cell->nbits)
+ nvmem_shift_read_buffer_in_place(cell, buf);
+
+ *len = cell->bytes;
+
+ return 0;
+}
+
+/**
+ * nvmem_cell_read() - Read a given nvmem cell
+ *
+ * @cell: nvmem cell to be read.
+ * @len: pointer to length of cell which will be populated on successful read.
+ *
+ * Return: ERR_PTR() on error or a valid pointer to a char * buffer on success.
+ * The buffer should be freed by the consumer with a kfree().
+ */
+void *nvmem_cell_read(struct nvmem_cell *cell, size_t *len)
+{
+ struct nvmem_device *nvmem = cell->nvmem;
+ u8 *buf;
+ int rc;
+
+ if (!nvmem)
+ return ERR_PTR(-EINVAL);
+
+ buf = kzalloc(cell->bytes, GFP_KERNEL);
+ if (!buf)
+ return ERR_PTR(-ENOMEM);
+
+ rc = __nvmem_cell_read(nvmem, cell, buf, len);
+ if (IS_ERR_VALUE(rc)) {
+ kfree(buf);
+ return ERR_PTR(rc);
+ }
+
+ return buf;
+}
+EXPORT_SYMBOL_GPL(nvmem_cell_read);
+
+static inline void *nvmem_cell_prepare_write_buffer(struct nvmem_cell *cell,
+ u8 *_buf, int len)
+{
+ struct nvmem_device *nvmem = cell->nvmem;
+ int i, rc, nbits, bit_offset = cell->bit_offset;
+ u8 v, *p, *buf, *b, pbyte, pbits;
+
+ nbits = cell->nbits;
+ buf = kzalloc(cell->bytes, GFP_KERNEL);
+ if (!buf)
+ return ERR_PTR(-ENOMEM);
+
+ memcpy(buf, _buf, len);
+ p = b = buf;
+
+ if (bit_offset) {
+ pbyte = *b;
+ *b <<= bit_offset;
+
+ /* setup the first byte with lsb bits from nvmem */
+ rc = nvmem->bus->read(&nvmem->dev, cell->offset, &v, 1);
+ *b++ |= GENMASK(bit_offset - 1, 0) & v;
+
+ /* setup rest of the byte if any */
+ for (i = 1; i < cell->bytes; i++) {
+ /* Get last byte bits and shift them towards lsb */
+ pbits = pbyte >> (BITS_PER_BYTE - 1 - bit_offset);
+ pbyte = *b;
+ p = b;
+ *b <<= bit_offset;
+ *b++ |= pbits;
+ }
+ }
+
+ /* if it's not end on byte boundary */
+ if ((nbits + bit_offset) % BITS_PER_BYTE) {
+ /* setup the last byte with msb bits from nvmem */
+ rc = nvmem->bus->read(&nvmem->dev, cell->offset + cell->bytes - 1,
+ &v, 1);
+ *p |= GENMASK(7, (nbits + bit_offset) % BITS_PER_BYTE) & v;
+
+ }
+
+ return buf;
+}
+
+/**
+ * nvmem_cell_write() - Write to a given nvmem cell
+ *
+ * @cell: nvmem cell to be written.
+ * @buf: Buffer to be written.
+ * @len: length of buffer to be written to nvmem cell.
+ *
+ * Return: length of bytes written or negative on failure.
+ */
+int nvmem_cell_write(struct nvmem_cell *cell, void *buf, size_t len)
+{
+ struct nvmem_device *nvmem = cell->nvmem;
+ int rc;
+
+ if (!nvmem || nvmem->read_only ||
+ (cell->bit_offset == 0 && len != cell->bytes))
+ return -EINVAL;
+
+ if (cell->bit_offset || cell->nbits) {
+ buf = nvmem_cell_prepare_write_buffer(cell, buf, len);
+ if (IS_ERR(buf))
+ return PTR_ERR(buf);
+ }
+
+ rc = nvmem->bus->write(&nvmem->dev, cell->offset, buf, cell->bytes);
+
+ /* free the tmp buffer */
+ if (cell->bit_offset || cell->nbits)
+ kfree(buf);
+
+ if (IS_ERR_VALUE(rc))
+ return rc;
+
+ return len;
+}
+EXPORT_SYMBOL_GPL(nvmem_cell_write);
+
+/**
+ * nvmem_device_cell_read() - Read a given nvmem device and cell
+ *
+ * @nvmem: nvmem device to read from.
+ * @info: nvmem cell info to be read.
+ * @buf: buffer pointer which will be populated on successful read.
+ *
+ * Return: length of successful bytes read on success and negative
+ * error code on error.
+ */
+ssize_t nvmem_device_cell_read(struct nvmem_device *nvmem,
+ struct nvmem_cell_info *info, void *buf)
+{
+ struct nvmem_cell cell;
+ int rc;
+ ssize_t len;
+
+ if (!nvmem)
+ return -EINVAL;
+
+ rc = nvmem_cell_info_to_nvmem_cell(nvmem, info, &cell);
+ if (IS_ERR_VALUE(rc))
+ return rc;
+
+ rc = __nvmem_cell_read(nvmem, &cell, buf, &len);
+ if (IS_ERR_VALUE(rc))
+ return rc;
+
+ return len;
+}
+EXPORT_SYMBOL_GPL(nvmem_device_cell_read);
+
+/**
+ * nvmem_device_cell_write() - Write cell to a given nvmem device
+ *
+ * @nvmem: nvmem device to be written to.
+ * @info: nvmem cell info to be written
+ * @buf: buffer to be written to cell.
+ *
+ * Return: length of bytes written or negative error code on failure.
+ * */
+int nvmem_device_cell_write(struct nvmem_device *nvmem,
+ struct nvmem_cell_info *info, void *buf)
+{
+ struct nvmem_cell cell;
+ int rc;
+
+ if (!nvmem)
+ return -EINVAL;
+
+ rc = nvmem_cell_info_to_nvmem_cell(nvmem, info, &cell);
+ if (IS_ERR_VALUE(rc))
+ return rc;
+
+ return nvmem_cell_write(&cell, buf, cell.bytes);
+}
+EXPORT_SYMBOL_GPL(nvmem_device_cell_write);
+
+/**
+ * nvmem_device_read() - Read from a given nvmem device
+ *
+ * @nvmem: nvmem device to read from.
+ * @offset: offset in nvmem device.
+ * @bytes: number of bytes to read.
+ * @buf: buffer pointer which will be populated on successful read.
+ *
+ * Return: length of successful bytes read on success and negative
+ * error code on error.
+ */
+int nvmem_device_read(struct nvmem_device *nvmem,
+ unsigned int offset,
+ size_t bytes, void *buf)
+{
+ int rc;
+
+ if (!nvmem)
+ return -EINVAL;
+
+ if (offset >= nvmem->size || bytes > nvmem->size - offset)
+ return -EINVAL;
+
+ if (!bytes)
+ return 0;
+
+ rc = nvmem->bus->read(&nvmem->dev, offset, buf, bytes);
+
+ if (IS_ERR_VALUE(rc))
+ return rc;
+
+ return bytes;
+}
+EXPORT_SYMBOL_GPL(nvmem_device_read);
+
+/**
+ * nvmem_device_write() - Write cell to a given nvmem device
+ *
+ * @nvmem: nvmem device to be written to.
+ * @offset: offset in nvmem device.
+ * @bytes: number of bytes to write.
+ * @buf: buffer to be written.
+ *
+ * Return: length of bytes written or negative error code on failure.
+ * */
+int nvmem_device_write(struct nvmem_device *nvmem,
+ unsigned int offset,
+ size_t bytes, const void *buf)
+{
+ int rc;
+
+ if (!nvmem || nvmem->read_only)
+ return -EINVAL;
+
+ if (offset >= nvmem->size || bytes > nvmem->size - offset)
+ return -EINVAL;
+
+ if (!bytes)
+ return 0;
+
+ rc = nvmem->bus->write(&nvmem->dev, offset, buf, bytes);
+
+ if (IS_ERR_VALUE(rc))
+ return rc;
+
+
+ return bytes;
+}
+EXPORT_SYMBOL_GPL(nvmem_device_write);
diff --git a/include/linux/nvmem-consumer.h b/include/linux/nvmem-consumer.h
new file mode 100644
index 000000000..606cadb49
--- /dev/null
+++ b/include/linux/nvmem-consumer.h
@@ -0,0 +1,94 @@
+/*
+ * nvmem framework consumer.
+ *
+ * Copyright (C) 2015 Srinivas Kandagatla <srinivas.kandagatla at linaro.org>
+ * Copyright (C) 2013 Maxime Ripard <maxime.ripard at free-electrons.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#ifndef _LINUX_NVMEM_CONSUMER_H
+#define _LINUX_NVMEM_CONSUMER_H
+
+struct device_d;
+struct device_node;
+/* consumer cookie */
+struct nvmem_cell;
+struct nvmem_device;
+
+struct nvmem_cell_info {
+ const char *name;
+ unsigned int offset;
+ unsigned int bytes;
+ unsigned int bit_offset;
+ unsigned int nbits;
+};
+
+#if IS_ENABLED(CONFIG_NVMEM)
+
+/* Cell based interface */
+struct nvmem_cell *nvmem_cell_get(struct device_d *dev, const char *name);
+void nvmem_cell_put(struct nvmem_cell *cell);
+void *nvmem_cell_read(struct nvmem_cell *cell, size_t *len);
+int nvmem_cell_write(struct nvmem_cell *cell, void *buf, size_t len);
+
+/* direct nvmem device read/write interface */
+struct nvmem_device *nvmem_device_get(struct device_d *dev, const char *name);
+void nvmem_device_put(struct nvmem_device *nvmem);
+
+#else
+
+static inline struct nvmem_cell *nvmem_cell_get(struct device_d *dev,
+ const char *name)
+{
+ return ERR_PTR(-ENOSYS);
+}
+
+static inline void nvmem_cell_put(struct nvmem_cell *cell)
+{
+}
+
+static inline char *nvmem_cell_read(struct nvmem_cell *cell, size_t *len)
+{
+ return ERR_PTR(-ENOSYS);
+}
+
+static inline int nvmem_cell_write(struct nvmem_cell *cell,
+ const char *buf, size_t len)
+{
+ return -ENOSYS;
+}
+
+static inline struct nvmem_device *nvmem_device_get(struct device_d *dev,
+ const char *name)
+{
+ return ERR_PTR(-ENOSYS);
+}
+
+static inline void nvmem_device_put(struct nvmem_device *nvmem)
+{
+}
+#endif /* CONFIG_NVMEM */
+
+#if IS_ENABLED(CONFIG_NVMEM) && IS_ENABLED(CONFIG_OFTREE)
+struct nvmem_cell *of_nvmem_cell_get(struct device_node *np,
+ const char *name);
+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 *name)
+{
+ return ERR_PTR(-ENOSYS);
+}
+
+static inline struct nvmem_device *of_nvmem_device_get(struct device_node *np,
+ const char *name)
+{
+ return ERR_PTR(-ENOSYS);
+}
+#endif /* CONFIG_NVMEM && CONFIG_OF */
+
+#endif /* ifndef _LINUX_NVMEM_CONSUMER_H */
diff --git a/include/linux/nvmem-provider.h b/include/linux/nvmem-provider.h
new file mode 100644
index 000000000..6ef5ea685
--- /dev/null
+++ b/include/linux/nvmem-provider.h
@@ -0,0 +1,49 @@
+/*
+ * nvmem framework provider.
+ *
+ * Copyright (C) 2015 Srinivas Kandagatla <srinivas.kandagatla at linaro.org>
+ * Copyright (C) 2013 Maxime Ripard <maxime.ripard at free-electrons.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#ifndef _LINUX_NVMEM_PROVIDER_H
+#define _LINUX_NVMEM_PROVIDER_H
+
+#include <common.h>
+#include <linux/types.h>
+
+struct nvmem_device;
+
+struct nvmem_bus {
+ int (*write)(struct device_d *dev, const int reg, const void *val,
+ int val_size);
+ int (*read)(struct device_d *dev, const int reg, void *val,
+ int val_size);
+};
+
+struct nvmem_config {
+ struct device_d *dev;
+ const char *name;
+ bool read_only;
+ int stride;
+ int word_size;
+ int size;
+ const struct nvmem_bus *bus;
+};
+
+#if IS_ENABLED(CONFIG_NVMEM)
+
+struct nvmem_device *nvmem_register(const struct nvmem_config *cfg);
+
+#else
+
+static inline struct nvmem_device *nvmem_register(const struct nvmem_config *c)
+{
+ return ERR_PTR(-ENOSYS);
+}
+
+#endif /* CONFIG_NVMEM */
+#endif /* ifndef _LINUX_NVMEM_PROVIDER_H */
--
2.11.0
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