[linux-2.6-block.git] / drivers / mtd / devices / powernv_flash.c

/*
 * OPAL PNOR flash MTD abstraction
 *
 * Copyright IBM 2015
 *
 * 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.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>

#include <linux/debugfs.h>
#include <linux/seq_file.h>

#include <asm/opal.h>


/*
 * This driver creates the a Linux MTD abstraction for platform PNOR flash
 * backed by OPAL calls
 */

struct powernv_flash {
	struct mtd_info	mtd;
	u32 id;
};

enum flash_op {
	FLASH_OP_READ,
	FLASH_OP_WRITE,
	FLASH_OP_ERASE,
};

static int powernv_flash_async_op(struct mtd_info *mtd, enum flash_op op,
		loff_t offset, size_t len, size_t *retlen, u_char *buf)
{
	struct powernv_flash *info = (struct powernv_flash *)mtd->priv;
	struct device *dev = &mtd->dev;
	int token;
	struct opal_msg msg;
	int rc;

	dev_dbg(dev, "%s(op=%d, offset=0x%llx, len=%zu)\n",
			__func__, op, offset, len);

	token = opal_async_get_token_interruptible();
	if (token < 0) {
		if (token != -ERESTARTSYS)
			dev_err(dev, "Failed to get an async token\n");

		return token;
	}

	switch (op) {
	case FLASH_OP_READ:
		rc = opal_flash_read(info->id, offset, __pa(buf), len, token);
		break;
	case FLASH_OP_WRITE:
		rc = opal_flash_write(info->id, offset, __pa(buf), len, token);
		break;
	case FLASH_OP_ERASE:
		rc = opal_flash_erase(info->id, offset, len, token);
		break;
	default:
		WARN_ON_ONCE(1);
		opal_async_release_token(token);
		return -EIO;
	}

	if (rc != OPAL_ASYNC_COMPLETION) {
		dev_err(dev, "opal_flash_async_op(op=%d) failed (rc %d)\n",
				op, rc);
		opal_async_release_token(token);
		return -EIO;
	}

	rc = opal_async_wait_response(token, &msg);
	opal_async_release_token(token);
	if (rc) {
		dev_err(dev, "opal async wait failed (rc %d)\n", rc);
		return -EIO;
	}

	rc = opal_get_async_rc(msg);
	if (rc == OPAL_SUCCESS) {
		rc = 0;
		if (retlen)
			*retlen = len;
	} else {
		rc = -EIO;
	}

	return rc;
}

/**
 * @mtd: the device
 * @from: the offset to read from
 * @len: the number of bytes to read
 * @retlen: the number of bytes actually read
 * @buf: the filled in buffer
 *
 * Returns 0 if read successful, or -ERRNO if an error occurred
 */
static int powernv_flash_read(struct mtd_info *mtd, loff_t from, size_t len,
	     size_t *retlen, u_char *buf)
{
	return powernv_flash_async_op(mtd, FLASH_OP_READ, from,
			len, retlen, buf);
}

/**
 * @mtd: the device
 * @to: the offset to write to
 * @len: the number of bytes to write
 * @retlen: the number of bytes actually written
 * @buf: the buffer to get bytes from
 *
 * Returns 0 if write successful, -ERRNO if error occurred
 */
static int powernv_flash_write(struct mtd_info *mtd, loff_t to, size_t len,
		     size_t *retlen, const u_char *buf)
{
	return powernv_flash_async_op(mtd, FLASH_OP_WRITE, to,
			len, retlen, (u_char *)buf);
}

/**
 * @mtd: the device
 * @erase: the erase info
 * Returns 0 if erase successful or -ERRNO if an error occurred
 */
static int powernv_flash_erase(struct mtd_info *mtd, struct erase_info *erase)
{
	int rc;

	erase->state = MTD_ERASING;

	/* todo: register our own notifier to do a true async implementation */
	rc =  powernv_flash_async_op(mtd, FLASH_OP_ERASE, erase->addr,
			erase->len, NULL, NULL);

	if (rc) {
		erase->fail_addr = erase->addr;
		erase->state = MTD_ERASE_FAILED;
	} else {
		erase->state = MTD_ERASE_DONE;
	}
	mtd_erase_callback(erase);
	return rc;
}

/**
 * powernv_flash_set_driver_info - Fill the mtd_info structure and docg3
 * structure @pdev: The platform device
 * @mtd: The structure to fill
 */
static int powernv_flash_set_driver_info(struct device *dev,
		struct mtd_info *mtd)
{
	u64 size;
	u32 erase_size;
	int rc;

	rc = of_property_read_u32(dev->of_node, "ibm,flash-block-size",
			&erase_size);
	if (rc) {
		dev_err(dev, "couldn't get resource block size information\n");
		return rc;
	}

	rc = of_property_read_u64(dev->of_node, "reg", &size);
	if (rc) {
		dev_err(dev, "couldn't get resource size information\n");
		return rc;
	}

	/*
	 * Going to have to check what details I need to set and how to
	 * get them
	 */
	mtd->name = of_get_property(dev->of_node, "name", NULL);
	mtd->type = MTD_NORFLASH;
	mtd->flags = MTD_WRITEABLE;
	mtd->size = size;
	mtd->erasesize = erase_size;
	mtd->writebufsize = mtd->writesize = 1;
	mtd->owner = THIS_MODULE;
	mtd->_erase = powernv_flash_erase;
	mtd->_read = powernv_flash_read;
	mtd->_write = powernv_flash_write;
	mtd->dev.parent = dev;
	return 0;
}

/**
 * powernv_flash_probe
 * @pdev: platform device
 *
 * Returns 0 on success, -ENOMEM, -ENXIO on error
 */
static int powernv_flash_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct powernv_flash *data;
	int ret;

	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
	if (!data) {
		ret = -ENOMEM;
		goto out;
	}
	data->mtd.priv = data;

	ret = of_property_read_u32(dev->of_node, "ibm,opal-id", &(data->id));
	if (ret) {
		dev_err(dev, "no device property 'ibm,opal-id'\n");
		goto out;
	}

	ret = powernv_flash_set_driver_info(dev, &data->mtd);
	if (ret)
		goto out;

	dev_set_drvdata(dev, data);

	/*
	 * The current flash that skiboot exposes is one contiguous flash chip
	 * with an ffs partition at the start, it should prove easier for users
	 * to deal with partitions or not as they see fit
	 */
	ret = mtd_device_register(&data->mtd, NULL, 0);

out:
	return ret;
}

/**
 * op_release - Release the driver
 * @pdev: the platform device
 *
 * Returns 0
 */
static int powernv_flash_release(struct platform_device *pdev)
{
	struct powernv_flash *data = dev_get_drvdata(&(pdev->dev));

	/* All resources should be freed automatically */
	return mtd_device_unregister(&(data->mtd));
}

static const struct of_device_id powernv_flash_match[] = {
	{ .compatible = "ibm,opal-flash" },
	{}
};

static struct platform_driver powernv_flash_driver = {
	.driver		= {
		.name		= "powernv_flash",
		.of_match_table	= powernv_flash_match,
	},
	.remove		= powernv_flash_release,
	.probe		= powernv_flash_probe,
};

module_platform_driver(powernv_flash_driver);

MODULE_DEVICE_TABLE(of, powernv_flash_match);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Cyril Bur <cyril.bur@au1.ibm.com>");
MODULE_DESCRIPTION("MTD abstraction for OPAL flash");
Commit	Line	Data
1cbb4a1c CB	1	/*
	2	* OPAL PNOR flash MTD abstraction
	3	*
	4	* Copyright IBM 2015
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; either version 2 of the License, or
	9	* (at your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*/
	16
	17	#include <linux/kernel.h>
	18	#include <linux/module.h>
	19	#include <linux/errno.h>
	20	#include <linux/of.h>
	21	#include <linux/of_address.h>
	22	#include <linux/platform_device.h>
	23	#include <linux/string.h>
	24	#include <linux/slab.h>
	25	#include <linux/mtd/mtd.h>
	26	#include <linux/mtd/partitions.h>
	27
	28	#include <linux/debugfs.h>
	29	#include <linux/seq_file.h>
	30
	31	#include <asm/opal.h>
	32
	33
	34	/*
	35	* This driver creates the a Linux MTD abstraction for platform PNOR flash
	36	* backed by OPAL calls
	37	*/
	38
	39	struct powernv_flash {
	40	struct mtd_info mtd;
	41	u32 id;
	42	};
	43
	44	enum flash_op {
	45	FLASH_OP_READ,
	46	FLASH_OP_WRITE,
	47	FLASH_OP_ERASE,
	48	};
	49
	50	static int powernv_flash_async_op(struct mtd_info *mtd, enum flash_op op,
	51	loff_t offset, size_t len, size_t retlen, u_char buf)
	52	{
	53	struct powernv_flash info = (struct powernv_flash )mtd->priv;
	54	struct device *dev = &mtd->dev;
	55	int token;
	56	struct opal_msg msg;
	57	int rc;
	58
	59	dev_dbg(dev, "%s(op=%d, offset=0x%llx, len=%zu)\n",
	60	__func__, op, offset, len);
	61
	62	token = opal_async_get_token_interruptible();
	63	if (token < 0) {
	64	if (token != -ERESTARTSYS)
65	dev_err(dev, "Failed to get an async token\n");
66
67	return token;
68	}
69
70	switch (op) {
71	case FLASH_OP_READ:
72	rc = opal_flash_read(info->id, offset, __pa(buf), len, token);
73	break;
74	case FLASH_OP_WRITE:
75	rc = opal_flash_write(info->id, offset, __pa(buf), len, token);
76	break;
77	case FLASH_OP_ERASE:
78	rc = opal_flash_erase(info->id, offset, len, token);
79	break;
80	default:
44e2aa2b CB	81	WARN_ON_ONCE(1);
	82	opal_async_release_token(token);
	83	return -EIO;
1cbb4a1c CB	84	}
	85
	86	if (rc != OPAL_ASYNC_COMPLETION) {
	87	dev_err(dev, "opal_flash_async_op(op=%d) failed (rc %d)\n",
	88	op, rc);
	89	opal_async_release_token(token);
	90	return -EIO;
	91	}
	92
	93	rc = opal_async_wait_response(token, &msg);
	94	opal_async_release_token(token);
	95	if (rc) {
	96	dev_err(dev, "opal async wait failed (rc %d)\n", rc);
	97	return -EIO;
	98	}
	99
d0226d31	100	rc = opal_get_async_rc(msg);
1cbb4a1c CB	101	if (rc == OPAL_SUCCESS) {
	102	rc = 0;
	103	if (retlen)
	104	*retlen = len;
	105	} else {
	106	rc = -EIO;
	107	}
	108
	109	return rc;
	110	}
	111
	112	/**
	113	* @mtd: the device
	114	* @from: the offset to read from
	115	* @len: the number of bytes to read
	116	* @retlen: the number of bytes actually read
	117	* @buf: the filled in buffer
	118	*
	119	* Returns 0 if read successful, or -ERRNO if an error occurred
	120	*/
	121	static int powernv_flash_read(struct mtd_info *mtd, loff_t from, size_t len,
	122	size_t retlen, u_char buf)
	123	{
	124	return powernv_flash_async_op(mtd, FLASH_OP_READ, from,
	125	len, retlen, buf);
	126	}
	127
	128	/**
	129	* @mtd: the device
	130	* @to: the offset to write to
	131	* @len: the number of bytes to write
	132	* @retlen: the number of bytes actually written
	133	* @buf: the buffer to get bytes from
	134	*
	135	* Returns 0 if write successful, -ERRNO if error occurred
	136	*/
	137	static int powernv_flash_write(struct mtd_info *mtd, loff_t to, size_t len,
	138	size_t retlen, const u_char buf)
	139	{
	140	return powernv_flash_async_op(mtd, FLASH_OP_WRITE, to,
	141	len, retlen, (u_char *)buf);
	142	}
	143
	144	/**
	145	* @mtd: the device
	146	* @erase: the erase info
	147	* Returns 0 if erase successful or -ERRNO if an error occurred
	148	*/
	149	static int powernv_flash_erase(struct mtd_info mtd, struct erase_info erase)
	150	{
	151	int rc;
	152
	153	erase->state = MTD_ERASING;
	154
	155	/* todo: register our own notifier to do a true async implementation */
	156	rc = powernv_flash_async_op(mtd, FLASH_OP_ERASE, erase->addr,
	157	erase->len, NULL, NULL);
	158
	159	if (rc) {
	160	erase->fail_addr = erase->addr;
	161	erase->state = MTD_ERASE_FAILED;
	162	} else {
	163	erase->state = MTD_ERASE_DONE;
	164	}
165	mtd_erase_callback(erase);
166	return rc;
167	}
168
169	/**
170	* powernv_flash_set_driver_info - Fill the mtd_info structure and docg3
171	* structure @pdev: The platform device
172	* @mtd: The structure to fill
173	*/
174	static int powernv_flash_set_driver_info(struct device *dev,
175	struct mtd_info *mtd)
176	{
177	u64 size;
178	u32 erase_size;
179	int rc;
180
181	rc = of_property_read_u32(dev->of_node, "ibm,flash-block-size",
182	&erase_size);
183	if (rc) {
184	dev_err(dev, "couldn't get resource block size information\n");
185	return rc;
186	}
187
188	rc = of_property_read_u64(dev->of_node, "reg", &size);
189	if (rc) {
190	dev_err(dev, "couldn't get resource size information\n");
191	return rc;
192	}
193
194	/*
195	* Going to have to check what details I need to set and how to
196	* get them
197	*/
198	mtd->name = of_get_property(dev->of_node, "name", NULL);
199	mtd->type = MTD_NORFLASH;
200	mtd->flags = MTD_WRITEABLE;
201	mtd->size = size;
202	mtd->erasesize = erase_size;
203	mtd->writebufsize = mtd->writesize = 1;
204	mtd->owner = THIS_MODULE;
205	mtd->_erase = powernv_flash_erase;
206	mtd->_read = powernv_flash_read;
207	mtd->_write = powernv_flash_write;
208	mtd->dev.parent = dev;
209	return 0;
210	}
211
212	/**
213	* powernv_flash_probe
214	* @pdev: platform device
215	*
216	* Returns 0 on success, -ENOMEM, -ENXIO on error
217	*/
218	static int powernv_flash_probe(struct platform_device *pdev)
219	{
220	struct device *dev = &pdev->dev;
221	struct powernv_flash *data;
222	int ret;
223
224	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
225	if (!data) {
226	ret = -ENOMEM;
227	goto out;
228	}
229	data->mtd.priv = data;
230
231	ret = of_property_read_u32(dev->of_node, "ibm,opal-id", &(data->id));
232	if (ret) {
233	dev_err(dev, "no device property 'ibm,opal-id'\n");
234	goto out;
235	}
236
237	ret = powernv_flash_set_driver_info(dev, &data->mtd);
238	if (ret)
239	goto out;
240
241	dev_set_drvdata(dev, data);
242
243	/*
244	* The current flash that skiboot exposes is one contiguous flash chip
245	* with an ffs partition at the start, it should prove easier for users
246	* to deal with partitions or not as they see fit
247	*/
248	ret = mtd_device_register(&data->mtd, NULL, 0);
249
250	out:
251	return ret;
252	}
253
254	/**
255	* op_release - Release the driver
256	* @pdev: the platform device
257	*
258	* Returns 0
259	*/
260	static int powernv_flash_release(struct platform_device *pdev)
261	{
262	struct powernv_flash *data = dev_get_drvdata(&(pdev->dev));
263
264	/* All resources should be freed automatically */
265	return mtd_device_unregister(&(data->mtd));
266	}
267
268	static const struct of_device_id powernv_flash_match[] = {
269	{ .compatible = "ibm,opal-flash" },
270	{}
271	};
272
273	static struct platform_driver powernv_flash_driver = {
274	.driver = {
275	.name = "powernv_flash",
276	.of_match_table = powernv_flash_match,
277	},
278	.remove = powernv_flash_release,
279	.probe = powernv_flash_probe,
280	};
281
282	module_platform_driver(powernv_flash_driver);
283
284	MODULE_DEVICE_TABLE(of, powernv_flash_match);
285	MODULE_LICENSE("GPL");
286	MODULE_AUTHOR("Cyril Bur <cyril.bur@au1.ibm.com>");
287	MODULE_DESCRIPTION("MTD abstraction for OPAL flash");