[deliverable/linux.git] / drivers / base / regmap / regmap-mmio.c

/*
 * Register map access API - MMIO support
 *
 * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>.
 */

#include <linux/err.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/regmap.h>
#include <linux/slab.h>

struct regmap_mmio_context {
	void __iomem *regs;
	unsigned val_bytes;
};

static int regmap_mmio_gather_write(void *context,
				    const void *reg, size_t reg_size,
				    const void *val, size_t val_size)
{
	struct regmap_mmio_context *ctx = context;
	u32 offset;

	BUG_ON(reg_size != 4);

	offset = be32_to_cpup(reg);

	while (val_size) {
		switch (ctx->val_bytes) {
		case 1:
			writeb(*(u8 *)val, ctx->regs + offset);
			break;
		case 2:
			writew(be16_to_cpup(val), ctx->regs + offset);
			break;
		case 4:
			writel(be32_to_cpup(val), ctx->regs + offset);
			break;
#ifdef CONFIG_64BIT
		case 8:
			writeq(be64_to_cpup(val), ctx->regs + offset);
			break;
#endif
		default:
			/* Should be caught by regmap_mmio_check_config */
			BUG();
		}
		val_size -= ctx->val_bytes;
		val += ctx->val_bytes;
		offset += ctx->val_bytes;
	}

	return 0;
}

static int regmap_mmio_write(void *context, const void *data, size_t count)
{
	BUG_ON(count < 4);

	return regmap_mmio_gather_write(context, data, 4, data + 4, count - 4);
}

static int regmap_mmio_read(void *context,
			    const void *reg, size_t reg_size,
			    void *val, size_t val_size)
{
	struct regmap_mmio_context *ctx = context;
	u32 offset;

	BUG_ON(reg_size != 4);

	offset = be32_to_cpup(reg);

	while (val_size) {
		switch (ctx->val_bytes) {
		case 1:
			*(u8 *)val = readb(ctx->regs + offset);
			break;
		case 2:
			*(u16 *)val = cpu_to_be16(readw(ctx->regs + offset));
			break;
		case 4:
			*(u32 *)val = cpu_to_be32(readl(ctx->regs + offset));
			break;
#ifdef CONFIG_64BIT
		case 8:
			*(u64 *)val = cpu_to_be32(readq(ctx->regs + offset));
			break;
#endif
		default:
			/* Should be caught by regmap_mmio_check_config */
			BUG();
		}
		val_size -= ctx->val_bytes;
		val += ctx->val_bytes;
		offset += ctx->val_bytes;
	}

	return 0;
}

static void regmap_mmio_free_context(void *context)
{
	kfree(context);
}

static struct regmap_bus regmap_mmio = {
	.fast_io = true,
	.write = regmap_mmio_write,
	.gather_write = regmap_mmio_gather_write,
	.read = regmap_mmio_read,
	.free_context = regmap_mmio_free_context,
};

struct regmap_mmio_context *regmap_mmio_gen_context(void __iomem *regs,
					const struct regmap_config *config)
{
	struct regmap_mmio_context *ctx;
	int min_stride;

	if (config->reg_bits != 32)
		return ERR_PTR(-EINVAL);

	if (config->pad_bits)
		return ERR_PTR(-EINVAL);

	switch (config->val_bits) {
	case 8:
		/* The core treats 0 as 1 */
		min_stride = 0;
		break;
	case 16:
		min_stride = 2;
		break;
	case 32:
		min_stride = 4;
		break;
#ifdef CONFIG_64BIT
	case 64:
		min_stride = 8;
		break;
#endif
		break;
	default:
		return ERR_PTR(-EINVAL);
	}

	if (config->reg_stride < min_stride)
		return ERR_PTR(-EINVAL);

	ctx = kzalloc(GFP_KERNEL, sizeof(*ctx));
	if (!ctx)
		return ERR_PTR(-ENOMEM);

	ctx->regs = regs;
	ctx->val_bytes = config->val_bits / 8;

	return ctx;
}

/**
 * regmap_init_mmio(): Initialise register map
 *
 * @dev: Device that will be interacted with
 * @regs: Pointer to memory-mapped IO region
 * @config: Configuration for register map
 *
 * The return value will be an ERR_PTR() on error or a valid pointer to
 * a struct regmap.
 */
struct regmap *regmap_init_mmio(struct device *dev,
				void __iomem *regs,
				const struct regmap_config *config)
{
	struct regmap_mmio_context *ctx;

	ctx = regmap_mmio_gen_context(regs, config);
	if (IS_ERR(ctx))
		return ERR_CAST(ctx);

	return regmap_init(dev, &regmap_mmio, ctx, config);
}
EXPORT_SYMBOL_GPL(regmap_init_mmio);

/**
 * devm_regmap_init_mmio(): Initialise managed register map
 *
 * @dev: Device that will be interacted with
 * @regs: Pointer to memory-mapped IO region
 * @config: Configuration for register map
 *
 * The return value will be an ERR_PTR() on error or a valid pointer
 * to a struct regmap.  The regmap will be automatically freed by the
 * device management code.
 */
struct regmap *devm_regmap_init_mmio(struct device *dev,
				     void __iomem *regs,
				     const struct regmap_config *config)
{
	struct regmap_mmio_context *ctx;

	ctx = regmap_mmio_gen_context(regs, config);
	if (IS_ERR(ctx))
		return ERR_CAST(ctx);

	return devm_regmap_init(dev, &regmap_mmio, ctx, config);
}
EXPORT_SYMBOL_GPL(devm_regmap_init_mmio);

MODULE_LICENSE("GPL v2");
Commit	Line	Data
45f5ff81 SW	1	/*
	2	* Register map access API - MMIO support
	3	*
	4	* Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved.
	5	*
	6	* This program is free software; you can redistribute it and/or modify it
	7	* under the terms and conditions of the GNU General Public License,
	8	* version 2, as published by the Free Software Foundation.
	9	*
	10	* This program is distributed in the hope it will be useful, but WITHOUT
	11	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	12	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	13	* more details.
	14	*
	15	* You should have received a copy of the GNU General Public License
	16	* along with this program. If not, see <http://www.gnu.org/licenses/>.
	17	*/
	18
	19	#include <linux/err.h>
	20	#include <linux/init.h>
	21	#include <linux/io.h>
	22	#include <linux/module.h>
	23	#include <linux/regmap.h>
	24	#include <linux/slab.h>
	25
	26	struct regmap_mmio_context {
	27	void __iomem *regs;
	28	unsigned val_bytes;
	29	};
	30
	31	static int regmap_mmio_gather_write(void *context,
	32	const void *reg, size_t reg_size,
	33	const void *val, size_t val_size)
	34	{
	35	struct regmap_mmio_context *ctx = context;
	36	u32 offset;
	37
40606dba SW	38	BUG_ON(reg_size != 4);
40606dba SW	39
45f5ff81 SW	40	offset = be32_to_cpup(reg);
	41
	42	while (val_size) {
	43	switch (ctx->val_bytes) {
	44	case 1:
	45	writeb((u8 )val, ctx->regs + offset);
	46	break;
	47	case 2:
	48	writew(be16_to_cpup(val), ctx->regs + offset);
	49	break;
	50	case 4:
	51	writel(be32_to_cpup(val), ctx->regs + offset);
	52	break;
	53	#ifdef CONFIG_64BIT
	54	case 8:
	55	writeq(be64_to_cpup(val), ctx->regs + offset);
	56	break;
	57	#endif
	58	default:
	59	/* Should be caught by regmap_mmio_check_config */
40606dba	60	BUG();
45f5ff81 SW	61	}
	62	val_size -= ctx->val_bytes;
	63	val += ctx->val_bytes;
	64	offset += ctx->val_bytes;
	65	}
	66
	67	return 0;
	68	}
	69
	70	static int regmap_mmio_write(void context, const void data, size_t count)
	71	{
40606dba SW	72	BUG_ON(count < 4);
40606dba SW	73
45f5ff81 SW	74	return regmap_mmio_gather_write(context, data, 4, data + 4, count - 4);
	75	}
	76
	77	static int regmap_mmio_read(void *context,
	78	const void *reg, size_t reg_size,
	79	void *val, size_t val_size)
	80	{
	81	struct regmap_mmio_context *ctx = context;
	82	u32 offset;
	83
40606dba SW	84	BUG_ON(reg_size != 4);
40606dba SW	85
45f5ff81 SW	86	offset = be32_to_cpup(reg);
	87
	88	while (val_size) {
	89	switch (ctx->val_bytes) {
	90	case 1:
	91	(u8 )val = readb(ctx->regs + offset);
	92	break;
	93	case 2:
	94	(u16 )val = cpu_to_be16(readw(ctx->regs + offset));
	95	break;
	96	case 4:
	97	(u32 )val = cpu_to_be32(readl(ctx->regs + offset));
	98	break;
	99	#ifdef CONFIG_64BIT
	100	case 8:
	101	(u64 )val = cpu_to_be32(readq(ctx->regs + offset));
	102	break;
	103	#endif
	104	default:
	105	/* Should be caught by regmap_mmio_check_config */
40606dba	106	BUG();
45f5ff81 SW	107	}
	108	val_size -= ctx->val_bytes;
	109	val += ctx->val_bytes;
	110	offset += ctx->val_bytes;
	111	}
	112
	113	return 0;
	114	}
	115
	116	static void regmap_mmio_free_context(void *context)
	117	{
	118	kfree(context);
	119	}
	120
	121	static struct regmap_bus regmap_mmio = {
	122	.fast_io = true,
	123	.write = regmap_mmio_write,
	124	.gather_write = regmap_mmio_gather_write,
	125	.read = regmap_mmio_read,
	126	.free_context = regmap_mmio_free_context,
	127	};
	128
	129	struct regmap_mmio_context regmap_mmio_gen_context(void __iomem regs,
	130	const struct regmap_config *config)
	131	{
	132	struct regmap_mmio_context *ctx;
f01ee60f	133	int min_stride;
45f5ff81 SW	134
	135	if (config->reg_bits != 32)
	136	return ERR_PTR(-EINVAL);
	137
	138	if (config->pad_bits)
	139	return ERR_PTR(-EINVAL);
	140
	141	switch (config->val_bits) {
	142	case 8:
f01ee60f SW	143	/* The core treats 0 as 1 */
	144	min_stride = 0;
	145	break;
45f5ff81	146	case 16:
f01ee60f SW	147	min_stride = 2;
f01ee60f SW	148	break;
45f5ff81	149	case 32:
f01ee60f SW	150	min_stride = 4;
f01ee60f SW	151	break;
45f5ff81 SW	152	#ifdef CONFIG_64BIT
45f5ff81 SW	153	case 64:
f01ee60f SW	154	min_stride = 8;
f01ee60f SW	155	break;
45f5ff81 SW	156	#endif
	157	break;
	158	default:
	159	return ERR_PTR(-EINVAL);
	160	}
	161
f01ee60f SW	162	if (config->reg_stride < min_stride)
	163	return ERR_PTR(-EINVAL);
	164
45f5ff81 SW	165	ctx = kzalloc(GFP_KERNEL, sizeof(*ctx));
	166	if (!ctx)
	167	return ERR_PTR(-ENOMEM);
	168
	169	ctx->regs = regs;
	170	ctx->val_bytes = config->val_bits / 8;
	171
	172	return ctx;
	173	}
	174
	175	/**
	176	* regmap_init_mmio(): Initialise register map
	177	*
	178	* @dev: Device that will be interacted with
	179	* @regs: Pointer to memory-mapped IO region
	180	* @config: Configuration for register map
	181	*
	182	* The return value will be an ERR_PTR() on error or a valid pointer to
	183	* a struct regmap.
	184	*/
	185	struct regmap regmap_init_mmio(struct device dev,
	186	void __iomem *regs,
	187	const struct regmap_config *config)
	188	{
	189	struct regmap_mmio_context *ctx;
	190
	191	ctx = regmap_mmio_gen_context(regs, config);
	192	if (IS_ERR(ctx))
	193	return ERR_CAST(ctx);
	194
	195	return regmap_init(dev, &regmap_mmio, ctx, config);
	196	}
	197	EXPORT_SYMBOL_GPL(regmap_init_mmio);
	198
	199	/**
	200	* devm_regmap_init_mmio(): Initialise managed register map
	201	*
	202	* @dev: Device that will be interacted with
	203	* @regs: Pointer to memory-mapped IO region
	204	* @config: Configuration for register map
	205	*
	206	* The return value will be an ERR_PTR() on error or a valid pointer
	207	* to a struct regmap. The regmap will be automatically freed by the
	208	* device management code.
	209	*/
	210	struct regmap devm_regmap_init_mmio(struct device dev,
	211	void __iomem *regs,
	212	const struct regmap_config *config)
	213	{
	214	struct regmap_mmio_context *ctx;
	215
	216	ctx = regmap_mmio_gen_context(regs, config);
	217	if (IS_ERR(ctx))
	218	return ERR_CAST(ctx);
	219
	220	return devm_regmap_init(dev, &regmap_mmio, ctx, config);
	221	}
	222	EXPORT_SYMBOL_GPL(devm_regmap_init_mmio);
	223
	224	MODULE_LICENSE("GPL v2");