[linux-2.6-block.git] / drivers / crypto / caam / caamrng.c

/*
 * caam - Freescale FSL CAAM support for hw_random
 *
 * Copyright 2011 Freescale Semiconductor, Inc.
 *
 * Based on caamalg.c crypto API driver.
 *
 * relationship between job descriptors to shared descriptors:
 *
 * ---------------                     --------------
 * | JobDesc #0  |-------------------->| ShareDesc  |
 * | *(buffer 0) |      |------------->| (generate) |
 * ---------------      |              | (move)     |
 *                      |              | (store)    |
 * ---------------      |              --------------
 * | JobDesc #1  |------|
 * | *(buffer 1) |
 * ---------------
 *
 * A job desc looks like this:
 *
 * ---------------------
 * | Header            |
 * | ShareDesc Pointer |
 * | SEQ_OUT_PTR       |
 * | (output buffer)   |
 * ---------------------
 *
 * The SharedDesc never changes, and each job descriptor points to one of two
 * buffers for each device, from which the data will be copied into the
 * requested destination
 */

#include <linux/hw_random.h>
#include <linux/completion.h>
#include <linux/atomic.h>

#include "compat.h"

#include "regs.h"
#include "intern.h"
#include "desc_constr.h"
#include "jr.h"
#include "error.h"

/*
 * Maximum buffer size: maximum number of random, cache-aligned bytes that
 * will be generated and moved to seq out ptr (extlen not allowed)
 */
#define RN_BUF_SIZE			(0xffff / L1_CACHE_BYTES * \
					 L1_CACHE_BYTES)

/* length of descriptors */
#define DESC_JOB_O_LEN			(CAAM_CMD_SZ * 2 + CAAM_PTR_SZ * 2)
#define DESC_RNG_LEN			(3 * CAAM_CMD_SZ)

/* Buffer, its dma address and lock */
struct buf_data {
	u8 buf[RN_BUF_SIZE] ____cacheline_aligned;
	dma_addr_t addr;
	struct completion filled;
	u32 hw_desc[DESC_JOB_O_LEN];
#define BUF_NOT_EMPTY 0
#define BUF_EMPTY 1
#define BUF_PENDING 2  /* Empty, but with job pending --don't submit another */
	atomic_t empty;
};

/* rng per-device context */
struct caam_rng_ctx {
	struct device *jrdev;
	dma_addr_t sh_desc_dma;
	u32 sh_desc[DESC_RNG_LEN];
	unsigned int cur_buf_idx;
	int current_buf;
	struct buf_data bufs[2];
};

static struct caam_rng_ctx *rng_ctx;

static inline void rng_unmap_buf(struct device *jrdev, struct buf_data *bd)
{
	if (bd->addr)
		dma_unmap_single(jrdev, bd->addr, RN_BUF_SIZE,
				 DMA_FROM_DEVICE);
}

static inline void rng_unmap_ctx(struct caam_rng_ctx *ctx)
{
	struct device *jrdev = ctx->jrdev;

	if (ctx->sh_desc_dma)
		dma_unmap_single(jrdev, ctx->sh_desc_dma,
				 desc_bytes(ctx->sh_desc), DMA_TO_DEVICE);
	rng_unmap_buf(jrdev, &ctx->bufs[0]);
	rng_unmap_buf(jrdev, &ctx->bufs[1]);
}

static void rng_done(struct device *jrdev, u32 *desc, u32 err, void *context)
{
	struct buf_data *bd;

	bd = container_of(desc, struct buf_data, hw_desc[0]);

	if (err)
		caam_jr_strstatus(jrdev, err);

	atomic_set(&bd->empty, BUF_NOT_EMPTY);
	complete(&bd->filled);

	/* Buffer refilled, invalidate cache */
	dma_sync_single_for_cpu(jrdev, bd->addr, RN_BUF_SIZE, DMA_FROM_DEVICE);

#ifdef DEBUG
	print_hex_dump(KERN_ERR, "rng refreshed buf@: ",
		       DUMP_PREFIX_ADDRESS, 16, 4, bd->buf, RN_BUF_SIZE, 1);
#endif
}

static inline int submit_job(struct caam_rng_ctx *ctx, int to_current)
{
	struct buf_data *bd = &ctx->bufs[!(to_current ^ ctx->current_buf)];
	struct device *jrdev = ctx->jrdev;
	u32 *desc = bd->hw_desc;
	int err;

	dev_dbg(jrdev, "submitting job %d\n", !(to_current ^ ctx->current_buf));
	init_completion(&bd->filled);
	err = caam_jr_enqueue(jrdev, desc, rng_done, ctx);
	if (err)
		complete(&bd->filled); /* don't wait on failed job*/
	else
		atomic_inc(&bd->empty); /* note if pending */

	return err;
}

static int caam_read(struct hwrng *rng, void *data, size_t max, bool wait)
{
	struct caam_rng_ctx *ctx = rng_ctx;
	struct buf_data *bd = &ctx->bufs[ctx->current_buf];
	int next_buf_idx, copied_idx;
	int err;

	if (atomic_read(&bd->empty)) {
		/* try to submit job if there wasn't one */
		if (atomic_read(&bd->empty) == BUF_EMPTY) {
			err = submit_job(ctx, 1);
			/* if can't submit job, can't even wait */
			if (err)
				return 0;
		}
		/* no immediate data, so exit if not waiting */
		if (!wait)
			return 0;

		/* waiting for pending job */
		if (atomic_read(&bd->empty))
			wait_for_completion(&bd->filled);
	}

	next_buf_idx = ctx->cur_buf_idx + max;
	dev_dbg(ctx->jrdev, "%s: start reading at buffer %d, idx %d\n",
		 __func__, ctx->current_buf, ctx->cur_buf_idx);

	/* if enough data in current buffer */
	if (next_buf_idx < RN_BUF_SIZE) {
		memcpy(data, bd->buf + ctx->cur_buf_idx, max);
		ctx->cur_buf_idx = next_buf_idx;
		return max;
	}

	/* else, copy what's left... */
	copied_idx = RN_BUF_SIZE - ctx->cur_buf_idx;
	memcpy(data, bd->buf + ctx->cur_buf_idx, copied_idx);
	ctx->cur_buf_idx = 0;
	atomic_set(&bd->empty, BUF_EMPTY);

	/* ...refill... */
	submit_job(ctx, 1);

	/* and use next buffer */
	ctx->current_buf = !ctx->current_buf;
	dev_dbg(ctx->jrdev, "switched to buffer %d\n", ctx->current_buf);

	/* since there already is some data read, don't wait */
	return copied_idx + caam_read(rng, data + copied_idx,
				      max - copied_idx, false);
}

static inline int rng_create_sh_desc(struct caam_rng_ctx *ctx)
{
	struct device *jrdev = ctx->jrdev;
	u32 *desc = ctx->sh_desc;

	init_sh_desc(desc, HDR_SHARE_SERIAL);

	/* Generate random bytes */
	append_operation(desc, OP_ALG_ALGSEL_RNG | OP_TYPE_CLASS1_ALG);

	/* Store bytes */
	append_seq_fifo_store(desc, RN_BUF_SIZE, FIFOST_TYPE_RNGSTORE);

	ctx->sh_desc_dma = dma_map_single(jrdev, desc, desc_bytes(desc),
					  DMA_TO_DEVICE);
	if (dma_mapping_error(jrdev, ctx->sh_desc_dma)) {
		dev_err(jrdev, "unable to map shared descriptor\n");
		return -ENOMEM;
	}
#ifdef DEBUG
	print_hex_dump(KERN_ERR, "rng shdesc@: ", DUMP_PREFIX_ADDRESS, 16, 4,
		       desc, desc_bytes(desc), 1);
#endif
	return 0;
}

static inline int rng_create_job_desc(struct caam_rng_ctx *ctx, int buf_id)
{
	struct device *jrdev = ctx->jrdev;
	struct buf_data *bd = &ctx->bufs[buf_id];
	u32 *desc = bd->hw_desc;
	int sh_len = desc_len(ctx->sh_desc);

	init_job_desc_shared(desc, ctx->sh_desc_dma, sh_len, HDR_SHARE_DEFER |
			     HDR_REVERSE);

	bd->addr = dma_map_single(jrdev, bd->buf, RN_BUF_SIZE, DMA_FROM_DEVICE);
	if (dma_mapping_error(jrdev, bd->addr)) {
		dev_err(jrdev, "unable to map dst\n");
		return -ENOMEM;
	}

	append_seq_out_ptr_intlen(desc, bd->addr, RN_BUF_SIZE, 0);
#ifdef DEBUG
	print_hex_dump(KERN_ERR, "rng job desc@: ", DUMP_PREFIX_ADDRESS, 16, 4,
		       desc, desc_bytes(desc), 1);
#endif
	return 0;
}

static void caam_cleanup(struct hwrng *rng)
{
	int i;
	struct buf_data *bd;

	for (i = 0; i < 2; i++) {
		bd = &rng_ctx->bufs[i];
		if (atomic_read(&bd->empty) == BUF_PENDING)
			wait_for_completion(&bd->filled);
	}

	rng_unmap_ctx(rng_ctx);
}

static int caam_init_buf(struct caam_rng_ctx *ctx, int buf_id)
{
	struct buf_data *bd = &ctx->bufs[buf_id];
	int err;

	err = rng_create_job_desc(ctx, buf_id);
	if (err)
		return err;

	atomic_set(&bd->empty, BUF_EMPTY);
	submit_job(ctx, buf_id == ctx->current_buf);
	wait_for_completion(&bd->filled);

	return 0;
}

static int caam_init_rng(struct caam_rng_ctx *ctx, struct device *jrdev)
{
	int err;

	ctx->jrdev = jrdev;

	err = rng_create_sh_desc(ctx);
	if (err)
		return err;

	ctx->current_buf = 0;
	ctx->cur_buf_idx = 0;

	err = caam_init_buf(ctx, 0);
	if (err)
		return err;

	err = caam_init_buf(ctx, 1);
	if (err)
		return err;

	return 0;
}

static struct hwrng caam_rng = {
	.name		= "rng-caam",
	.cleanup	= caam_cleanup,
	.read		= caam_read,
};

static void __exit caam_rng_exit(void)
{
	caam_jr_free(rng_ctx->jrdev);
	hwrng_unregister(&caam_rng);
	kfree(rng_ctx);
}

static int __init caam_rng_init(void)
{
	struct device *dev;
	struct device_node *dev_node;
	struct platform_device *pdev;
	struct device *ctrldev;
	struct caam_drv_private *priv;
	int err;

	dev_node = of_find_compatible_node(NULL, NULL, "fsl,sec-v4.0");
	if (!dev_node) {
		dev_node = of_find_compatible_node(NULL, NULL, "fsl,sec4.0");
		if (!dev_node)
			return -ENODEV;
	}

	pdev = of_find_device_by_node(dev_node);
	if (!pdev) {
		of_node_put(dev_node);
		return -ENODEV;
	}

	ctrldev = &pdev->dev;
	priv = dev_get_drvdata(ctrldev);
	of_node_put(dev_node);

	/*
	 * If priv is NULL, it's probably because the caam driver wasn't
	 * properly initialized (e.g. RNG4 init failed). Thus, bail out here.
	 */
	if (!priv)
		return -ENODEV;

	/* Check for an instantiated RNG before registration */
	if (!(rd_reg32(&priv->ctrl->perfmon.cha_num_ls) & CHA_ID_LS_RNG_MASK))
		return -ENODEV;

	dev = caam_jr_alloc();
	if (IS_ERR(dev)) {
		pr_err("Job Ring Device allocation for transform failed\n");
		return PTR_ERR(dev);
	}
	rng_ctx = kmalloc(sizeof(*rng_ctx), GFP_DMA | GFP_KERNEL);
	if (!rng_ctx) {
		err = -ENOMEM;
		goto free_caam_alloc;
	}
	err = caam_init_rng(rng_ctx, dev);
	if (err)
		goto free_rng_ctx;

	dev_info(dev, "registering rng-caam\n");
	return hwrng_register(&caam_rng);

free_rng_ctx:
	kfree(rng_ctx);
free_caam_alloc:
	caam_jr_free(dev);
	return err;
}

module_init(caam_rng_init);
module_exit(caam_rng_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("FSL CAAM support for hw_random API");
MODULE_AUTHOR("Freescale Semiconductor - NMG");
Commit	Line	Data
e24f7c9e YK	1	/*
	2	* caam - Freescale FSL CAAM support for hw_random
	3	*
	4	* Copyright 2011 Freescale Semiconductor, Inc.
	5	*
	6	* Based on caamalg.c crypto API driver.
	7	*
	8	* relationship between job descriptors to shared descriptors:
	9	*
	10	* --------------- --------------
	11	* \| JobDesc #0 \|-------------------->\| ShareDesc \|
	12	* \| *(buffer 0) \| \|------------->\| (generate) \|
	13	* --------------- \| \| (move) \|
	14	* \| \| (store) \|
	15	* --------------- \| --------------
	16	* \| JobDesc #1 \|------\|
	17	* \| *(buffer 1) \|
	18	* ---------------
	19	*
	20	* A job desc looks like this:
	21	*
	22	* ---------------------
	23	* \| Header \|
	24	* \| ShareDesc Pointer \|
	25	* \| SEQ_OUT_PTR \|
	26	* \| (output buffer) \|
	27	* ---------------------
	28	*
	29	* The SharedDesc never changes, and each job descriptor points to one of two
	30	* buffers for each device, from which the data will be copied into the
	31	* requested destination
	32	*/
	33
	34	#include <linux/hw_random.h>
	35	#include <linux/completion.h>
	36	#include <linux/atomic.h>
	37
	38	#include "compat.h"
	39
	40	#include "regs.h"
	41	#include "intern.h"
	42	#include "desc_constr.h"
	43	#include "jr.h"
	44	#include "error.h"
	45
	46	/*
	47	* Maximum buffer size: maximum number of random, cache-aligned bytes that
	48	* will be generated and moved to seq out ptr (extlen not allowed)
	49	*/
	50	#define RN_BUF_SIZE (0xffff / L1_CACHE_BYTES * \
	51	L1_CACHE_BYTES)
	52
	53	/* length of descriptors */
	54	#define DESC_JOB_O_LEN (CAAM_CMD_SZ * 2 + CAAM_PTR_SZ * 2)
39957c8e	55	#define DESC_RNG_LEN (3 * CAAM_CMD_SZ)
e24f7c9e YK	56
	57	/* Buffer, its dma address and lock */
	58	struct buf_data {
412c98c1	59	u8 buf[RN_BUF_SIZE] ____cacheline_aligned;
e24f7c9e YK	60	dma_addr_t addr;
	61	struct completion filled;
	62	u32 hw_desc[DESC_JOB_O_LEN];
	63	#define BUF_NOT_EMPTY 0
	64	#define BUF_EMPTY 1
	65	#define BUF_PENDING 2 /* Empty, but with job pending --don't submit another */
	66	atomic_t empty;
	67	};
	68
	69	/* rng per-device context */
	70	struct caam_rng_ctx {
	71	struct device *jrdev;
	72	dma_addr_t sh_desc_dma;
	73	u32 sh_desc[DESC_RNG_LEN];
	74	unsigned int cur_buf_idx;
	75	int current_buf;
	76	struct buf_data bufs[2];
	77	};
	78
6e4e603a	79	static struct caam_rng_ctx *rng_ctx;
e24f7c9e YK	80
	81	static inline void rng_unmap_buf(struct device jrdev, struct buf_data bd)
	82	{
	83	if (bd->addr)
	84	dma_unmap_single(jrdev, bd->addr, RN_BUF_SIZE,
	85	DMA_FROM_DEVICE);
	86	}
	87
	88	static inline void rng_unmap_ctx(struct caam_rng_ctx *ctx)
	89	{
	90	struct device *jrdev = ctx->jrdev;
	91
	92	if (ctx->sh_desc_dma)
4842234f YJ	93	dma_unmap_single(jrdev, ctx->sh_desc_dma,
4842234f YJ	94	desc_bytes(ctx->sh_desc), DMA_TO_DEVICE);
e24f7c9e YK	95	rng_unmap_buf(jrdev, &ctx->bufs[0]);
	96	rng_unmap_buf(jrdev, &ctx->bufs[1]);
	97	}
	98
	99	static void rng_done(struct device jrdev, u32 desc, u32 err, void *context)
	100	{
	101	struct buf_data *bd;
	102
4ca7c7d8	103	bd = container_of(desc, struct buf_data, hw_desc[0]);
e24f7c9e	104
fa9659cd MV	105	if (err)
fa9659cd MV	106	caam_jr_strstatus(jrdev, err);
e24f7c9e YK	107
	108	atomic_set(&bd->empty, BUF_NOT_EMPTY);
	109	complete(&bd->filled);
e7472422 VM	110
	111	/* Buffer refilled, invalidate cache */
	112	dma_sync_single_for_cpu(jrdev, bd->addr, RN_BUF_SIZE, DMA_FROM_DEVICE);
	113
e24f7c9e YK	114	#ifdef DEBUG
	115	print_hex_dump(KERN_ERR, "rng refreshed buf@: ",
	116	DUMP_PREFIX_ADDRESS, 16, 4, bd->buf, RN_BUF_SIZE, 1);
	117	#endif
	118	}
	119
	120	static inline int submit_job(struct caam_rng_ctx *ctx, int to_current)
	121	{
	122	struct buf_data *bd = &ctx->bufs[!(to_current ^ ctx->current_buf)];
	123	struct device *jrdev = ctx->jrdev;
	124	u32 *desc = bd->hw_desc;
	125	int err;
	126
	127	dev_dbg(jrdev, "submitting job %d\n", !(to_current ^ ctx->current_buf));
	128	init_completion(&bd->filled);
	129	err = caam_jr_enqueue(jrdev, desc, rng_done, ctx);
	130	if (err)
	131	complete(&bd->filled); /* don't wait on failed job*/
	132	else
	133	atomic_inc(&bd->empty); /* note if pending */
	134
	135	return err;
	136	}
	137
	138	static int caam_read(struct hwrng rng, void data, size_t max, bool wait)
	139	{
6e4e603a	140	struct caam_rng_ctx *ctx = rng_ctx;
e24f7c9e YK	141	struct buf_data *bd = &ctx->bufs[ctx->current_buf];
	142	int next_buf_idx, copied_idx;
	143	int err;
	144
	145	if (atomic_read(&bd->empty)) {
	146	/* try to submit job if there wasn't one */
	147	if (atomic_read(&bd->empty) == BUF_EMPTY) {
	148	err = submit_job(ctx, 1);
	149	/* if can't submit job, can't even wait */
	150	if (err)
	151	return 0;
	152	}
	153	/* no immediate data, so exit if not waiting */
	154	if (!wait)
	155	return 0;
	156
	157	/* waiting for pending job */
	158	if (atomic_read(&bd->empty))
	159	wait_for_completion(&bd->filled);
	160	}
	161
	162	next_buf_idx = ctx->cur_buf_idx + max;
	163	dev_dbg(ctx->jrdev, "%s: start reading at buffer %d, idx %d\n",
	164	__func__, ctx->current_buf, ctx->cur_buf_idx);
	165
	166	/* if enough data in current buffer */
	167	if (next_buf_idx < RN_BUF_SIZE) {
	168	memcpy(data, bd->buf + ctx->cur_buf_idx, max);
	169	ctx->cur_buf_idx = next_buf_idx;
	170	return max;
	171	}
	172
	173	/* else, copy what's left... */
	174	copied_idx = RN_BUF_SIZE - ctx->cur_buf_idx;
	175	memcpy(data, bd->buf + ctx->cur_buf_idx, copied_idx);
	176	ctx->cur_buf_idx = 0;
	177	atomic_set(&bd->empty, BUF_EMPTY);
	178
	179	/* ...refill... */
	180	submit_job(ctx, 1);
	181
	182	/* and use next buffer */
	183	ctx->current_buf = !ctx->current_buf;
	184	dev_dbg(ctx->jrdev, "switched to buffer %d\n", ctx->current_buf);
	185
	186	/* since there already is some data read, don't wait */
	187	return copied_idx + caam_read(rng, data + copied_idx,
	188	max - copied_idx, false);
	189	}
	190
ce572085	191	static inline int rng_create_sh_desc(struct caam_rng_ctx *ctx)
e24f7c9e YK	192	{
	193	struct device *jrdev = ctx->jrdev;
	194	u32 *desc = ctx->sh_desc;
	195
61bb86bb	196	init_sh_desc(desc, HDR_SHARE_SERIAL);
e24f7c9e	197
e24f7c9e YK	198	/* Generate random bytes */
	199	append_operation(desc, OP_ALG_ALGSEL_RNG \| OP_TYPE_CLASS1_ALG);
	200
	201	/* Store bytes */
	202	append_seq_fifo_store(desc, RN_BUF_SIZE, FIFOST_TYPE_RNGSTORE);
	203
	204	ctx->sh_desc_dma = dma_map_single(jrdev, desc, desc_bytes(desc),
	205	DMA_TO_DEVICE);
ce572085 HG	206	if (dma_mapping_error(jrdev, ctx->sh_desc_dma)) {
	207	dev_err(jrdev, "unable to map shared descriptor\n");
	208	return -ENOMEM;
	209	}
e24f7c9e YK	210	#ifdef DEBUG
	211	print_hex_dump(KERN_ERR, "rng shdesc@: ", DUMP_PREFIX_ADDRESS, 16, 4,
	212	desc, desc_bytes(desc), 1);
	213	#endif
ce572085	214	return 0;
e24f7c9e YK	215	}
e24f7c9e YK	216
ce572085	217	static inline int rng_create_job_desc(struct caam_rng_ctx *ctx, int buf_id)
e24f7c9e YK	218	{
	219	struct device *jrdev = ctx->jrdev;
	220	struct buf_data *bd = &ctx->bufs[buf_id];
	221	u32 *desc = bd->hw_desc;
	222	int sh_len = desc_len(ctx->sh_desc);
	223
	224	init_job_desc_shared(desc, ctx->sh_desc_dma, sh_len, HDR_SHARE_DEFER \|
	225	HDR_REVERSE);
	226
	227	bd->addr = dma_map_single(jrdev, bd->buf, RN_BUF_SIZE, DMA_FROM_DEVICE);
ce572085 HG	228	if (dma_mapping_error(jrdev, bd->addr)) {
	229	dev_err(jrdev, "unable to map dst\n");
	230	return -ENOMEM;
	231	}
e24f7c9e YK	232
	233	append_seq_out_ptr_intlen(desc, bd->addr, RN_BUF_SIZE, 0);
	234	#ifdef DEBUG
	235	print_hex_dump(KERN_ERR, "rng job desc@: ", DUMP_PREFIX_ADDRESS, 16, 4,
	236	desc, desc_bytes(desc), 1);
	237	#endif
ce572085	238	return 0;
e24f7c9e YK	239	}
	240
	241	static void caam_cleanup(struct hwrng *rng)
	242	{
	243	int i;
	244	struct buf_data *bd;
	245
	246	for (i = 0; i < 2; i++) {
6e4e603a	247	bd = &rng_ctx->bufs[i];
e24f7c9e YK	248	if (atomic_read(&bd->empty) == BUF_PENDING)
	249	wait_for_completion(&bd->filled);
	250	}
	251
6e4e603a	252	rng_unmap_ctx(rng_ctx);
e24f7c9e YK	253	}
e24f7c9e YK	254
ce572085	255	static int caam_init_buf(struct caam_rng_ctx *ctx, int buf_id)
e24f7c9e YK	256	{
e24f7c9e YK	257	struct buf_data *bd = &ctx->bufs[buf_id];
ce572085 HG	258	int err;
	259
	260	err = rng_create_job_desc(ctx, buf_id);
	261	if (err)
	262	return err;
e24f7c9e	263
e24f7c9e YK	264	atomic_set(&bd->empty, BUF_EMPTY);
	265	submit_job(ctx, buf_id == ctx->current_buf);
	266	wait_for_completion(&bd->filled);
ce572085 HG	267
ce572085 HG	268	return 0;
e24f7c9e YK	269	}
e24f7c9e YK	270
ce572085	271	static int caam_init_rng(struct caam_rng_ctx ctx, struct device jrdev)
e24f7c9e	272	{
ce572085 HG	273	int err;
ce572085 HG	274
e24f7c9e	275	ctx->jrdev = jrdev;
ce572085 HG	276
	277	err = rng_create_sh_desc(ctx);
	278	if (err)
	279	return err;
	280
e24f7c9e YK	281	ctx->current_buf = 0;
e24f7c9e YK	282	ctx->cur_buf_idx = 0;
ce572085 HG	283
	284	err = caam_init_buf(ctx, 0);
	285	if (err)
	286	return err;
	287
	288	err = caam_init_buf(ctx, 1);
	289	if (err)
	290	return err;
	291
	292	return 0;
e24f7c9e YK	293	}
	294
	295	static struct hwrng caam_rng = {
	296	.name = "rng-caam",
	297	.cleanup = caam_cleanup,
	298	.read = caam_read,
	299	};
	300
	301	static void __exit caam_rng_exit(void)
	302	{
6e4e603a	303	caam_jr_free(rng_ctx->jrdev);
e24f7c9e	304	hwrng_unregister(&caam_rng);
6e4e603a	305	kfree(rng_ctx);
e24f7c9e YK	306	}
	307
	308	static int __init caam_rng_init(void)
	309	{
cfc6f11b	310	struct device *dev;
35af6403 RG	311	struct device_node *dev_node;
	312	struct platform_device *pdev;
	313	struct device *ctrldev;
bf83490e	314	struct caam_drv_private *priv;
ce572085	315	int err;
35af6403 RG	316
	317	dev_node = of_find_compatible_node(NULL, NULL, "fsl,sec-v4.0");
	318	if (!dev_node) {
	319	dev_node = of_find_compatible_node(NULL, NULL, "fsl,sec4.0");
	320	if (!dev_node)
	321	return -ENODEV;
	322	}
	323
	324	pdev = of_find_device_by_node(dev_node);
	325	if (!pdev) {
	326	of_node_put(dev_node);
	327	return -ENODEV;
	328	}
	329
	330	ctrldev = &pdev->dev;
	331	priv = dev_get_drvdata(ctrldev);
	332	of_node_put(dev_node);
	333
	334	/*
	335	* If priv is NULL, it's probably because the caam driver wasn't
	336	* properly initialized (e.g. RNG4 init failed). Thus, bail out here.
	337	*/
	338	if (!priv)
	339	return -ENODEV;
e24f7c9e	340
bf83490e VM	341	/* Check for an instantiated RNG before registration */
	342	if (!(rd_reg32(&priv->ctrl->perfmon.cha_num_ls) & CHA_ID_LS_RNG_MASK))
	343	return -ENODEV;
	344
cfc6f11b RG	345	dev = caam_jr_alloc();
	346	if (IS_ERR(dev)) {
	347	pr_err("Job Ring Device allocation for transform failed\n");
	348	return PTR_ERR(dev);
	349	}
c530e341	350	rng_ctx = kmalloc(sizeof(*rng_ctx), GFP_DMA \| GFP_KERNEL);
ac8ad307 FE	351	if (!rng_ctx) {
	352	err = -ENOMEM;
	353	goto free_caam_alloc;
	354	}
ce572085 HG	355	err = caam_init_rng(rng_ctx, dev);
ce572085 HG	356	if (err)
ac8ad307	357	goto free_rng_ctx;
e24f7c9e	358
cfc6f11b	359	dev_info(dev, "registering rng-caam\n");
e24f7c9e	360	return hwrng_register(&caam_rng);
ac8ad307 FE	361
	362	free_rng_ctx:
	363	kfree(rng_ctx);
	364	free_caam_alloc:
	365	caam_jr_free(dev);
	366	return err;
e24f7c9e YK	367	}
	368
	369	module_init(caam_rng_init);
	370	module_exit(caam_rng_exit);
	371
	372	MODULE_LICENSE("GPL");
	373	MODULE_DESCRIPTION("FSL CAAM support for hw_random API");
	374	MODULE_AUTHOR("Freescale Semiconductor - NMG");