[linux-2.6-block.git] / drivers / misc / sram.c

/*
 * Generic on-chip SRAM allocation driver
 *
 * Copyright (C) 2012 Philipp Zabel, Pengutronix
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 * MA 02110-1301, USA.
 */

#include <linux/clk.h>
#include <linux/genalloc.h>
#include <linux/io.h>
#include <linux/list_sort.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

#define SRAM_GRANULARITY	32

struct sram_partition {
	void __iomem *base;

	struct gen_pool *pool;
	struct bin_attribute battr;
	struct mutex lock;
};

struct sram_dev {
	struct device *dev;
	void __iomem *virt_base;

	struct gen_pool *pool;
	struct clk *clk;

	struct sram_partition *partition;
	u32 partitions;
};

struct sram_reserve {
	struct list_head list;
	u32 start;
	u32 size;
	bool export;
	bool pool;
	const char *label;
};

static ssize_t sram_read(struct file *filp, struct kobject *kobj,
			 struct bin_attribute *attr,
			 char *buf, loff_t pos, size_t count)
{
	struct sram_partition *part;

	part = container_of(attr, struct sram_partition, battr);

	mutex_lock(&part->lock);
	memcpy_fromio(buf, part->base + pos, count);
	mutex_unlock(&part->lock);

	return count;
}

static ssize_t sram_write(struct file *filp, struct kobject *kobj,
			  struct bin_attribute *attr,
			  char *buf, loff_t pos, size_t count)
{
	struct sram_partition *part;

	part = container_of(attr, struct sram_partition, battr);

	mutex_lock(&part->lock);
	memcpy_toio(part->base + pos, buf, count);
	mutex_unlock(&part->lock);

	return count;
}

static int sram_add_pool(struct sram_dev *sram, struct sram_reserve *block,
			 phys_addr_t start, struct sram_partition *part)
{
	int ret;

	part->pool = devm_gen_pool_create(sram->dev, ilog2(SRAM_GRANULARITY),
					  NUMA_NO_NODE, block->label);
	if (IS_ERR(part->pool))
		return PTR_ERR(part->pool);

	ret = gen_pool_add_virt(part->pool, (unsigned long)part->base, start,
				block->size, NUMA_NO_NODE);
	if (ret < 0) {
		dev_err(sram->dev, "failed to register subpool: %d\n", ret);
		return ret;
	}

	return 0;
}

static int sram_add_export(struct sram_dev *sram, struct sram_reserve *block,
			   phys_addr_t start, struct sram_partition *part)
{
	sysfs_bin_attr_init(&part->battr);
	part->battr.attr.name = devm_kasprintf(sram->dev, GFP_KERNEL,
					       "%llx.sram",
					       (unsigned long long)start);
	if (!part->battr.attr.name)
		return -ENOMEM;

	part->battr.attr.mode = S_IRUSR | S_IWUSR;
	part->battr.read = sram_read;
	part->battr.write = sram_write;
	part->battr.size = block->size;

	return device_create_bin_file(sram->dev, &part->battr);
}

static int sram_add_partition(struct sram_dev *sram, struct sram_reserve *block,
			      phys_addr_t start)
{
	int ret;
	struct sram_partition *part = &sram->partition[sram->partitions];

	mutex_init(&part->lock);
	part->base = sram->virt_base + block->start;

	if (block->pool) {
		ret = sram_add_pool(sram, block, start, part);
		if (ret)
			return ret;
	}
	if (block->export) {
		ret = sram_add_export(sram, block, start, part);
		if (ret)
			return ret;
	}
	sram->partitions++;

	return 0;
}

static void sram_free_partitions(struct sram_dev *sram)
{
	struct sram_partition *part;

	if (!sram->partitions)
		return;

	part = &sram->partition[sram->partitions - 1];
	for (; sram->partitions; sram->partitions--, part--) {
		if (part->battr.size)
			device_remove_bin_file(sram->dev, &part->battr);

		if (part->pool &&
		    gen_pool_avail(part->pool) < gen_pool_size(part->pool))
			dev_err(sram->dev, "removed pool while SRAM allocated\n");
	}
}

static int sram_reserve_cmp(void *priv, struct list_head *a,
					struct list_head *b)
{
	struct sram_reserve *ra = list_entry(a, struct sram_reserve, list);
	struct sram_reserve *rb = list_entry(b, struct sram_reserve, list);

	return ra->start - rb->start;
}

static int sram_reserve_regions(struct sram_dev *sram, struct resource *res)
{
	struct device_node *np = sram->dev->of_node, *child;
	unsigned long size, cur_start, cur_size;
	struct sram_reserve *rblocks, *block;
	struct list_head reserve_list;
	unsigned int nblocks, exports = 0;
	const char *label;
	int ret = 0;

	INIT_LIST_HEAD(&reserve_list);

	size = resource_size(res);

	/*
	 * We need an additional block to mark the end of the memory region
	 * after the reserved blocks from the dt are processed.
	 */
	nblocks = (np) ? of_get_available_child_count(np) + 1 : 1;
	rblocks = kzalloc((nblocks) * sizeof(*rblocks), GFP_KERNEL);
	if (!rblocks)
		return -ENOMEM;

	block = &rblocks[0];
	for_each_available_child_of_node(np, child) {
		struct resource child_res;

		ret = of_address_to_resource(child, 0, &child_res);
		if (ret < 0) {
			dev_err(sram->dev,
				"could not get address for node %s\n",
				child->full_name);
			goto err_chunks;
		}

		if (child_res.start < res->start || child_res.end > res->end) {
			dev_err(sram->dev,
				"reserved block %s outside the sram area\n",
				child->full_name);
			ret = -EINVAL;
			goto err_chunks;
		}

		block->start = child_res.start - res->start;
		block->size = resource_size(&child_res);
		list_add_tail(&block->list, &reserve_list);

		if (of_find_property(child, "export", NULL))
			block->export = true;

		if (of_find_property(child, "pool", NULL))
			block->pool = true;

		if ((block->export || block->pool) && block->size) {
			exports++;

			label = NULL;
			ret = of_property_read_string(child, "label", &label);
			if (ret && ret != -EINVAL) {
				dev_err(sram->dev,
					"%s has invalid label name\n",
					child->full_name);
				goto err_chunks;
			}
			if (!label)
				label = child->name;

			block->label = devm_kstrdup(sram->dev,
						    label, GFP_KERNEL);
			if (!block->label)
				goto err_chunks;

			dev_dbg(sram->dev, "found %sblock '%s' 0x%x-0x%x\n",
				block->export ? "exported " : "", block->label,
				block->start, block->start + block->size);
		} else {
			dev_dbg(sram->dev, "found reserved block 0x%x-0x%x\n",
				block->start, block->start + block->size);
		}

		block++;
	}
	child = NULL;

	/* the last chunk marks the end of the region */
	rblocks[nblocks - 1].start = size;
	rblocks[nblocks - 1].size = 0;
	list_add_tail(&rblocks[nblocks - 1].list, &reserve_list);

	list_sort(NULL, &reserve_list, sram_reserve_cmp);

	if (exports) {
		sram->partition = devm_kzalloc(sram->dev,
				       exports * sizeof(*sram->partition),
				       GFP_KERNEL);
		if (!sram->partition) {
			ret = -ENOMEM;
			goto err_chunks;
		}
	}

	cur_start = 0;
	list_for_each_entry(block, &reserve_list, list) {
		/* can only happen if sections overlap */
		if (block->start < cur_start) {
			dev_err(sram->dev,
				"block at 0x%x starts after current offset 0x%lx\n",
				block->start, cur_start);
			ret = -EINVAL;
			sram_free_partitions(sram);
			goto err_chunks;
		}

		if ((block->export || block->pool) && block->size) {
			ret = sram_add_partition(sram, block,
						 res->start + block->start);
			if (ret) {
				sram_free_partitions(sram);
				goto err_chunks;
			}
		}

		/* current start is in a reserved block, so continue after it */
		if (block->start == cur_start) {
			cur_start = block->start + block->size;
			continue;
		}

		/*
		 * allocate the space between the current starting
		 * address and the following reserved block, or the
		 * end of the region.
		 */
		cur_size = block->start - cur_start;

		dev_dbg(sram->dev, "adding chunk 0x%lx-0x%lx\n",
			cur_start, cur_start + cur_size);

		ret = gen_pool_add_virt(sram->pool,
				(unsigned long)sram->virt_base + cur_start,
				res->start + cur_start, cur_size, -1);
		if (ret < 0) {
			sram_free_partitions(sram);
			goto err_chunks;
		}

		/* next allocation after this reserved block */
		cur_start = block->start + block->size;
	}

 err_chunks:
	if (child)
		of_node_put(child);

	kfree(rblocks);

	return ret;
}

static int sram_probe(struct platform_device *pdev)
{
	struct sram_dev *sram;
	struct resource *res;
	size_t size;
	int ret;

	sram = devm_kzalloc(&pdev->dev, sizeof(*sram), GFP_KERNEL);
	if (!sram)
		return -ENOMEM;

	sram->dev = &pdev->dev;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res) {
		dev_err(sram->dev, "found no memory resource\n");
		return -EINVAL;
	}

	size = resource_size(res);

	if (!devm_request_mem_region(sram->dev, res->start, size, pdev->name)) {
		dev_err(sram->dev, "could not request region for resource\n");
		return -EBUSY;
	}

	if (of_property_read_bool(pdev->dev.of_node, "no-memory-wc"))
		sram->virt_base = devm_ioremap(sram->dev, res->start, size);
	else
		sram->virt_base = devm_ioremap_wc(sram->dev, res->start, size);
	if (IS_ERR(sram->virt_base))
		return PTR_ERR(sram->virt_base);

	sram->pool = devm_gen_pool_create(sram->dev, ilog2(SRAM_GRANULARITY),
					  NUMA_NO_NODE, NULL);
	if (IS_ERR(sram->pool))
		return PTR_ERR(sram->pool);

	ret = sram_reserve_regions(sram, res);
	if (ret)
		return ret;

	sram->clk = devm_clk_get(sram->dev, NULL);
	if (IS_ERR(sram->clk))
		sram->clk = NULL;
	else
		clk_prepare_enable(sram->clk);

	platform_set_drvdata(pdev, sram);

	dev_dbg(sram->dev, "SRAM pool: %zu KiB @ 0x%p\n",
		gen_pool_size(sram->pool) / 1024, sram->virt_base);

	return 0;
}

static int sram_remove(struct platform_device *pdev)
{
	struct sram_dev *sram = platform_get_drvdata(pdev);

	sram_free_partitions(sram);

	if (gen_pool_avail(sram->pool) < gen_pool_size(sram->pool))
		dev_err(sram->dev, "removed while SRAM allocated\n");

	if (sram->clk)
		clk_disable_unprepare(sram->clk);

	return 0;
}

#ifdef CONFIG_OF
static const struct of_device_id sram_dt_ids[] = {
	{ .compatible = "mmio-sram" },
	{}
};
#endif

static struct platform_driver sram_driver = {
	.driver = {
		.name = "sram",
		.of_match_table = of_match_ptr(sram_dt_ids),
	},
	.probe = sram_probe,
	.remove = sram_remove,
};

static int __init sram_init(void)
{
	return platform_driver_register(&sram_driver);
}

postcore_initcall(sram_init);
Commit	Line	Data
4984c6f5 PZ	1	/*
	2	* Generic on-chip SRAM allocation driver
	3	*
	4	* Copyright (C) 2012 Philipp Zabel, Pengutronix
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public License
	8	* as published by the Free Software Foundation; either version 2
	9	* of the License, or (at your option) any later version.
	10	* This program is distributed in the hope that it will be useful,
	11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	* GNU General Public License for more details.
	14	*
	15	* You should have received a copy of the GNU General Public License
	16	* along with this program; if not, write to the Free Software
	17	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
	18	* MA 02110-1301, USA.
	19	*/
	20
4984c6f5	21	#include <linux/clk.h>
98ce2d27	22	#include <linux/genalloc.h>
4984c6f5	23	#include <linux/io.h>
2da19688	24	#include <linux/list_sort.h>
98ce2d27	25	#include <linux/of_address.h>
4984c6f5 PZ	26	#include <linux/platform_device.h>
4984c6f5 PZ	27	#include <linux/slab.h>
4984c6f5 PZ	28
	29	#define SRAM_GRANULARITY 32
	30
b4c3fcb3	31	struct sram_partition {
525d12f2	32	void __iomem *base;
b4c3fcb3 VZ	33
	34	struct gen_pool *pool;
	35	struct bin_attribute battr;
	36	struct mutex lock;
	37	};
	38
4984c6f5	39	struct sram_dev {
665d82fb VZ	40	struct device *dev;
	41	void __iomem *virt_base;
	42
4984c6f5 PZ	43	struct gen_pool *pool;
4984c6f5 PZ	44	struct clk *clk;
b4c3fcb3 VZ	45
	46	struct sram_partition *partition;
	47	u32 partitions;
4984c6f5 PZ	48	};
4984c6f5 PZ	49
2da19688 HS	50	struct sram_reserve {
	51	struct list_head list;
	52	u32 start;
	53	u32 size;
b4c3fcb3 VZ	54	bool export;
	55	bool pool;
	56	const char *label;
2da19688 HS	57	};
2da19688 HS	58
b4c3fcb3 VZ	59	static ssize_t sram_read(struct file filp, struct kobject kobj,
	60	struct bin_attribute *attr,
	61	char *buf, loff_t pos, size_t count)
	62	{
	63	struct sram_partition *part;
	64
	65	part = container_of(attr, struct sram_partition, battr);
	66
	67	mutex_lock(&part->lock);
525d12f2	68	memcpy_fromio(buf, part->base + pos, count);
b4c3fcb3 VZ	69	mutex_unlock(&part->lock);
	70
	71	return count;
	72	}
	73
	74	static ssize_t sram_write(struct file filp, struct kobject kobj,
	75	struct bin_attribute *attr,
	76	char *buf, loff_t pos, size_t count)
	77	{
	78	struct sram_partition *part;
	79
	80	part = container_of(attr, struct sram_partition, battr);
	81
	82	mutex_lock(&part->lock);
525d12f2	83	memcpy_toio(part->base + pos, buf, count);
b4c3fcb3 VZ	84	mutex_unlock(&part->lock);
	85
	86	return count;
	87	}
	88
	89	static int sram_add_pool(struct sram_dev sram, struct sram_reserve block,
	90	phys_addr_t start, struct sram_partition *part)
	91	{
	92	int ret;
	93
	94	part->pool = devm_gen_pool_create(sram->dev, ilog2(SRAM_GRANULARITY),
	95	NUMA_NO_NODE, block->label);
	96	if (IS_ERR(part->pool))
	97	return PTR_ERR(part->pool);
	98
	99	ret = gen_pool_add_virt(part->pool, (unsigned long)part->base, start,
	100	block->size, NUMA_NO_NODE);
	101	if (ret < 0) {
	102	dev_err(sram->dev, "failed to register subpool: %d\n", ret);
	103	return ret;
	104	}
	105
	106	return 0;
	107	}
	108
	109	static int sram_add_export(struct sram_dev sram, struct sram_reserve block,
	110	phys_addr_t start, struct sram_partition *part)
	111	{
	112	sysfs_bin_attr_init(&part->battr);
	113	part->battr.attr.name = devm_kasprintf(sram->dev, GFP_KERNEL,
	114	"%llx.sram",
	115	(unsigned long long)start);
	116	if (!part->battr.attr.name)
	117	return -ENOMEM;
	118
	119	part->battr.attr.mode = S_IRUSR \| S_IWUSR;
	120	part->battr.read = sram_read;
	121	part->battr.write = sram_write;
	122	part->battr.size = block->size;
	123
	124	return device_create_bin_file(sram->dev, &part->battr);
	125	}
	126
	127	static int sram_add_partition(struct sram_dev sram, struct sram_reserve block,
	128	phys_addr_t start)
	129	{
	130	int ret;
	131	struct sram_partition *part = &sram->partition[sram->partitions];
	132
	133	mutex_init(&part->lock);
	134	part->base = sram->virt_base + block->start;
	135
	136	if (block->pool) {
	137	ret = sram_add_pool(sram, block, start, part);
	138	if (ret)
	139	return ret;
	140	}
	141	if (block->export) {
	142	ret = sram_add_export(sram, block, start, part);
	143	if (ret)
	144	return ret;
	145	}
	146	sram->partitions++;
	147
148	return 0;
149	}
150
151	static void sram_free_partitions(struct sram_dev *sram)
152	{
153	struct sram_partition *part;
154
155	if (!sram->partitions)
156	return;
157
158	part = &sram->partition[sram->partitions - 1];
159	for (; sram->partitions; sram->partitions--, part--) {
160	if (part->battr.size)
161	device_remove_bin_file(sram->dev, &part->battr);
162
163	if (part->pool &&
164	gen_pool_avail(part->pool) < gen_pool_size(part->pool))
165	dev_err(sram->dev, "removed pool while SRAM allocated\n");
166	}
167	}
168
2da19688 HS	169	static int sram_reserve_cmp(void priv, struct list_head a,
	170	struct list_head *b)
	171	{
	172	struct sram_reserve *ra = list_entry(a, struct sram_reserve, list);
	173	struct sram_reserve *rb = list_entry(b, struct sram_reserve, list);
	174
	175	return ra->start - rb->start;
	176	}
	177
a0a5be0b	178	static int sram_reserve_regions(struct sram_dev sram, struct resource res)
4984c6f5	179	{
a0a5be0b	180	struct device_node np = sram->dev->of_node, child;
2da19688 HS	181	unsigned long size, cur_start, cur_size;
	182	struct sram_reserve rblocks, block;
	183	struct list_head reserve_list;
b4c3fcb3 VZ	184	unsigned int nblocks, exports = 0;
b4c3fcb3 VZ	185	const char *label;
a0a5be0b	186	int ret = 0;
4984c6f5	187
2da19688 HS	188	INIT_LIST_HEAD(&reserve_list);
2da19688 HS	189
f3cbfa5d	190	size = resource_size(res);
4984c6f5	191
2da19688 HS	192	/*
	193	* We need an additional block to mark the end of the memory region
	194	* after the reserved blocks from the dt are processed.
	195	*/
	196	nblocks = (np) ? of_get_available_child_count(np) + 1 : 1;
b4c3fcb3	197	rblocks = kzalloc((nblocks) * sizeof(*rblocks), GFP_KERNEL);
ee895ccd VZ	198	if (!rblocks)
ee895ccd VZ	199	return -ENOMEM;
4984c6f5	200
2da19688 HS	201	block = &rblocks[0];
	202	for_each_available_child_of_node(np, child) {
	203	struct resource child_res;
	204
	205	ret = of_address_to_resource(child, 0, &child_res);
	206	if (ret < 0) {
665d82fb	207	dev_err(sram->dev,
2da19688 HS	208	"could not get address for node %s\n",
	209	child->full_name);
	210	goto err_chunks;
	211	}
	212
	213	if (child_res.start < res->start \|\| child_res.end > res->end) {
665d82fb	214	dev_err(sram->dev,
2da19688 HS	215	"reserved block %s outside the sram area\n",
	216	child->full_name);
	217	ret = -EINVAL;
	218	goto err_chunks;
	219	}
	220
	221	block->start = child_res.start - res->start;
	222	block->size = resource_size(&child_res);
	223	list_add_tail(&block->list, &reserve_list);
	224
b4c3fcb3 VZ	225	if (of_find_property(child, "export", NULL))
	226	block->export = true;
	227
	228	if (of_find_property(child, "pool", NULL))
	229	block->pool = true;
	230
	231	if ((block->export \|\| block->pool) && block->size) {
	232	exports++;
	233
	234	label = NULL;
	235	ret = of_property_read_string(child, "label", &label);
	236	if (ret && ret != -EINVAL) {
	237	dev_err(sram->dev,
	238	"%s has invalid label name\n",
	239	child->full_name);
	240	goto err_chunks;
	241	}
	242	if (!label)
	243	label = child->name;
	244
	245	block->label = devm_kstrdup(sram->dev,
	246	label, GFP_KERNEL);
	247	if (!block->label)
	248	goto err_chunks;
	249
	250	dev_dbg(sram->dev, "found %sblock '%s' 0x%x-0x%x\n",
	251	block->export ? "exported " : "", block->label,
	252	block->start, block->start + block->size);
	253	} else {
	254	dev_dbg(sram->dev, "found reserved block 0x%x-0x%x\n",
	255	block->start, block->start + block->size);
	256	}
2da19688 HS	257
	258	block++;
	259	}
b4c3fcb3	260	child = NULL;
2da19688 HS	261
	262	/* the last chunk marks the end of the region */
	263	rblocks[nblocks - 1].start = size;
	264	rblocks[nblocks - 1].size = 0;
	265	list_add_tail(&rblocks[nblocks - 1].list, &reserve_list);
	266
	267	list_sort(NULL, &reserve_list, sram_reserve_cmp);
	268
b4c3fcb3 VZ	269	if (exports) {
	270	sram->partition = devm_kzalloc(sram->dev,
	271	exports * sizeof(*sram->partition),
	272	GFP_KERNEL);
	273	if (!sram->partition) {
	274	ret = -ENOMEM;
	275	goto err_chunks;
	276	}
	277	}
2da19688	278
b4c3fcb3	279	cur_start = 0;
2da19688 HS	280	list_for_each_entry(block, &reserve_list, list) {
	281	/* can only happen if sections overlap */
	282	if (block->start < cur_start) {
665d82fb	283	dev_err(sram->dev,
2da19688 HS	284	"block at 0x%x starts after current offset 0x%lx\n",
	285	block->start, cur_start);
	286	ret = -EINVAL;
b4c3fcb3	287	sram_free_partitions(sram);
2da19688 HS	288	goto err_chunks;
	289	}
	290
b4c3fcb3 VZ	291	if ((block->export \|\| block->pool) && block->size) {
	292	ret = sram_add_partition(sram, block,
	293	res->start + block->start);
	294	if (ret) {
	295	sram_free_partitions(sram);
	296	goto err_chunks;
	297	}
	298	}
	299
2da19688 HS	300	/* current start is in a reserved block, so continue after it */
	301	if (block->start == cur_start) {
	302	cur_start = block->start + block->size;
	303	continue;
	304	}
	305
	306	/*
	307	* allocate the space between the current starting
	308	* address and the following reserved block, or the
	309	* end of the region.
	310	*/
	311	cur_size = block->start - cur_start;
	312
665d82fb	313	dev_dbg(sram->dev, "adding chunk 0x%lx-0x%lx\n",
2da19688	314	cur_start, cur_start + cur_size);
665d82fb	315
2da19688	316	ret = gen_pool_add_virt(sram->pool,
665d82fb	317	(unsigned long)sram->virt_base + cur_start,
2da19688	318	res->start + cur_start, cur_size, -1);
b4c3fcb3 VZ	319	if (ret < 0) {
b4c3fcb3 VZ	320	sram_free_partitions(sram);
2da19688	321	goto err_chunks;
b4c3fcb3	322	}
2da19688 HS	323
	324	/* next allocation after this reserved block */
	325	cur_start = block->start + block->size;
	326	}
	327
a0a5be0b	328	err_chunks:
b4c3fcb3 VZ	329	if (child)
	330	of_node_put(child);
	331
2da19688 HS	332	kfree(rblocks);
2da19688 HS	333
a0a5be0b VZ	334	return ret;
	335	}
	336
	337	static int sram_probe(struct platform_device *pdev)
	338	{
	339	struct sram_dev *sram;
	340	struct resource *res;
	341	size_t size;
	342	int ret;
	343
	344	sram = devm_kzalloc(&pdev->dev, sizeof(*sram), GFP_KERNEL);
	345	if (!sram)
	346	return -ENOMEM;
	347
	348	sram->dev = &pdev->dev;
	349
	350	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	351	if (!res) {
	352	dev_err(sram->dev, "found no memory resource\n");
	353	return -EINVAL;
	354	}
	355
	356	size = resource_size(res);
	357
	358	if (!devm_request_mem_region(sram->dev, res->start, size, pdev->name)) {
	359	dev_err(sram->dev, "could not request region for resource\n");
	360	return -EBUSY;
	361	}
	362
eb43e023 MW	363	if (of_property_read_bool(pdev->dev.of_node, "no-memory-wc"))
	364	sram->virt_base = devm_ioremap(sram->dev, res->start, size);
	365	else
	366	sram->virt_base = devm_ioremap_wc(sram->dev, res->start, size);
a0a5be0b VZ	367	if (IS_ERR(sram->virt_base))
	368	return PTR_ERR(sram->virt_base);
	369
73858173 VZ	370	sram->pool = devm_gen_pool_create(sram->dev, ilog2(SRAM_GRANULARITY),
	371	NUMA_NO_NODE, NULL);
	372	if (IS_ERR(sram->pool))
	373	return PTR_ERR(sram->pool);
a0a5be0b VZ	374
	375	ret = sram_reserve_regions(sram, res);
	376	if (ret)
	377	return ret;
	378
665d82fb	379	sram->clk = devm_clk_get(sram->dev, NULL);
ee895ccd VZ	380	if (IS_ERR(sram->clk))
	381	sram->clk = NULL;
	382	else
	383	clk_prepare_enable(sram->clk);
	384
4984c6f5 PZ	385	platform_set_drvdata(pdev, sram);
4984c6f5 PZ	386
665d82fb VZ	387	dev_dbg(sram->dev, "SRAM pool: %zu KiB @ 0x%p\n",
665d82fb VZ	388	gen_pool_size(sram->pool) / 1024, sram->virt_base);
4984c6f5 PZ	389
	390	return 0;
	391	}
	392
	393	static int sram_remove(struct platform_device *pdev)
	394	{
	395	struct sram_dev *sram = platform_get_drvdata(pdev);
	396
b4c3fcb3 VZ	397	sram_free_partitions(sram);
b4c3fcb3 VZ	398
4984c6f5	399	if (gen_pool_avail(sram->pool) < gen_pool_size(sram->pool))
665d82fb	400	dev_err(sram->dev, "removed while SRAM allocated\n");
4984c6f5	401
4984c6f5 PZ	402	if (sram->clk)
	403	clk_disable_unprepare(sram->clk);
	404
	405	return 0;
	406	}
	407
	408	#ifdef CONFIG_OF
6893d9b5	409	static const struct of_device_id sram_dt_ids[] = {
4984c6f5 PZ	410	{ .compatible = "mmio-sram" },
	411	{}
	412	};
	413	#endif
	414
	415	static struct platform_driver sram_driver = {
	416	.driver = {
	417	.name = "sram",
	418	.of_match_table = of_match_ptr(sram_dt_ids),
	419	},
	420	.probe = sram_probe,
	421	.remove = sram_remove,
	422	};
	423
	424	static int __init sram_init(void)
	425	{
	426	return platform_driver_register(&sram_driver);
	427	}
	428
	429	postcore_initcall(sram_init);