Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 0fc0aae6 authored by Bartosz Golaszewski's avatar Bartosz Golaszewski Committed by Mark Salyzyn
Browse files

BACKPORT: nvmem: resolve cells from DT at registration time 



Currently we're creating a new cell structure everytime a DT user
calls nvmem_cell_get().

Change this behavior by resolving the cells during nvmem provider
registration and adding all cells to the provider's list. Make
of_nvmem_cell_get() just parse the phandle and look the cell up
in the relevant provider's list.

Don't drop the cell in nvmem_cell_put().

Signed-off-by: default avatarBartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: default avatarSrinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Git-commit: e888d445ac33a5b0288d670ecd970908b13f07cd
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Signed-off-by: default avatarGaurav Kohli <gkohli@codeaurora.org>
(cherry picked from commit e888d445ac33a5b0288d670ecd970908b13f07cd)
Signed-off-by: default avatarMark Salyzyn <salyzyn@google.com>
Bug: 150014847
Change-Id: Ic1372c4179da11814f5622d4999c7c87e6c2986a
parent 4dc41997

drivers/nvmem/core.c

+75 −48
Original line number Diff line number Diff line
@@ -446,6 +446,73 @@ static int nvmem_setup_compat(struct nvmem_device *nvmem, 
	return 0;

}



static struct nvmem_cell *

nvmem_find_cell_by_index(struct nvmem_device *nvmem, int index)

{

	struct nvmem_cell *cell = NULL;

	int i = 0;



	mutex_lock(&nvmem_mutex);

	list_for_each_entry(cell, &nvmem_cells, node) {

		if (index == i++)

			break;

	}

	mutex_unlock(&nvmem_mutex);



	return cell;

}



static int nvmem_add_cells_from_of(struct nvmem_device *nvmem)

{

	struct device_node *parent, *child;

	struct device *dev = &nvmem->dev;

	struct nvmem_cell *cell;

	const __be32 *addr;

	int len;



	parent = dev->of_node;



	for_each_child_of_node(parent, child) {

		addr = of_get_property(child, "reg", &len);

		if (!addr || (len < 2 * sizeof(u32))) {

			dev_err(dev, "nvmem: invalid reg on %pOF\n", child);

			return -EINVAL;

		}



		cell = kzalloc(sizeof(*cell), GFP_KERNEL);

		if (!cell)

			return -ENOMEM;



		cell->nvmem = nvmem;

		cell->offset = be32_to_cpup(addr++);

		cell->bytes = be32_to_cpup(addr);

		cell->name = child->name;



		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);

		}



		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(dev, "cell %s unaligned to nvmem stride %d\n",

				cell->name, nvmem->stride);

			/* Cells already added will be freed later. */

			kfree(cell);

			return -EINVAL;

		}



		nvmem_cell_add(cell);

	}



	return 0;

}



/**

 * nvmem_register() - Register a nvmem device for given nvmem_config.

 * Also creates an binary entry in /sys/bus/nvmem/devices/dev-name/nvmem
@@ -529,6 +596,10 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config) 
			goto err_teardown_compat;

	}



	rval = nvmem_add_cells_from_of(nvmem);

	if (rval)

		goto err_teardown_compat;



	return nvmem;



err_teardown_compat:
@@ -852,10 +923,8 @@ 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;

	struct nvmem_cell *cell;

	int index = 0;



	/* if cell name exists, find index to the name */
@@ -875,54 +944,13 @@ struct nvmem_cell *of_nvmem_cell_get(struct device_node *np, 
	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 %pOF\n",

			cell_np);

		rval  = -EINVAL;

		goto err_mem;

	}



	cell = kzalloc(sizeof(*cell), GFP_KERNEL);

	cell = nvmem_find_cell_by_index(nvmem, index);

	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 (!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_device_put(nvmem);

		return ERR_PTR(-ENOENT);

	}



	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
@@ -1028,7 +1056,6 @@ 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);