1/*
 2 * Register map access API - SPI support
 3 *
 4 * Copyright 2011 Wolfson Microelectronics plc
 5 *
 6 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
 7 *
 8 * This program is free software; you can redistribute it and/or modify
 9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12
13#include <linux/regmap.h>
14#include <linux/spi/spi.h>
15#include <linux/init.h>
16#include <linux/module.h>
17
18static int regmap_spi_write(struct device *dev, const void *data, size_t count)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
19{
 
20	struct spi_device *spi = to_spi_device(dev);
21
22	return spi_write(spi, data, count);
23}
24
25static int regmap_spi_gather_write(struct device *dev,
26				   const void *reg, size_t reg_len,
27				   const void *val, size_t val_len)
28{
 
29	struct spi_device *spi = to_spi_device(dev);
30	struct spi_message m;
31	struct spi_transfer t[2] = { { .tx_buf = reg, .len = reg_len, },
32				     { .tx_buf = val, .len = val_len, }, };
33
34	spi_message_init(&m);
35	spi_message_add_tail(&t[0], &m);
36	spi_message_add_tail(&t[1], &m);
37
38	return spi_sync(spi, &m);
39}
40
41static int regmap_spi_read(struct device *dev,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
42			   const void *reg, size_t reg_size,
43			   void *val, size_t val_size)
44{
 
45	struct spi_device *spi = to_spi_device(dev);
46
47	return spi_write_then_read(spi, reg, reg_size, val, val_size);
48}
49
50static struct regmap_bus regmap_spi = {
51	.type = &spi_bus_type,
52	.write = regmap_spi_write,
53	.gather_write = regmap_spi_gather_write,
 
 
54	.read = regmap_spi_read,
55	.owner = THIS_MODULE,
56	.read_flag_mask = 0x80,
 
 
57};
58
59/**
60 * regmap_init_spi(): Initialise register map
61 *
62 * @spi: Device that will be interacted with
63 * @config: Configuration for register map
64 *
65 * The return value will be an ERR_PTR() on error or a valid pointer to
66 * a struct regmap.
67 */
68struct regmap *regmap_init_spi(struct spi_device *spi,
69			       const struct regmap_config *config)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
70{
71	return regmap_init(&spi->dev, &regmap_spi, config);
 
 
 
 
 
72}
73EXPORT_SYMBOL_GPL(regmap_init_spi);
74
 
75MODULE_LICENSE("GPL");

  1// SPDX-License-Identifier: GPL-2.0
  2//
  3// Register map access API - SPI support
  4//
  5// Copyright 2011 Wolfson Microelectronics plc
  6//
  7// Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
 
 
 
 
  8
  9#include <linux/regmap.h>
 10#include <linux/spi/spi.h>
 
 11#include <linux/module.h>
 12
 13#include "internal.h"
 14
 15struct regmap_async_spi {
 16	struct regmap_async core;
 17	struct spi_message m;
 18	struct spi_transfer t[2];
 19};
 20
 21static void regmap_spi_complete(void *data)
 22{
 23	struct regmap_async_spi *async = data;
 24
 25	regmap_async_complete_cb(&async->core, async->m.status);
 26}
 27
 28static int regmap_spi_write(void *context, const void *data, size_t count)
 29{
 30	struct device *dev = context;
 31	struct spi_device *spi = to_spi_device(dev);
 32
 33	return spi_write(spi, data, count);
 34}
 35
 36static int regmap_spi_gather_write(void *context,
 37				   const void *reg, size_t reg_len,
 38				   const void *val, size_t val_len)
 39{
 40	struct device *dev = context;
 41	struct spi_device *spi = to_spi_device(dev);
 42	struct spi_message m;
 43	struct spi_transfer t[2] = { { .tx_buf = reg, .len = reg_len, },
 44				     { .tx_buf = val, .len = val_len, }, };
 45
 46	spi_message_init(&m);
 47	spi_message_add_tail(&t[0], &m);
 48	spi_message_add_tail(&t[1], &m);
 49
 50	return spi_sync(spi, &m);
 51}
 52
 53static int regmap_spi_async_write(void *context,
 54				  const void *reg, size_t reg_len,
 55				  const void *val, size_t val_len,
 56				  struct regmap_async *a)
 57{
 58	struct regmap_async_spi *async = container_of(a,
 59						      struct regmap_async_spi,
 60						      core);
 61	struct device *dev = context;
 62	struct spi_device *spi = to_spi_device(dev);
 63
 64	async->t[0].tx_buf = reg;
 65	async->t[0].len = reg_len;
 66	async->t[1].tx_buf = val;
 67	async->t[1].len = val_len;
 68
 69	spi_message_init(&async->m);
 70	spi_message_add_tail(&async->t[0], &async->m);
 71	if (val)
 72		spi_message_add_tail(&async->t[1], &async->m);
 73
 74	async->m.complete = regmap_spi_complete;
 75	async->m.context = async;
 76
 77	return spi_async(spi, &async->m);
 78}
 79
 80static struct regmap_async *regmap_spi_async_alloc(void)
 81{
 82	struct regmap_async_spi *async_spi;
 83
 84	async_spi = kzalloc(sizeof(*async_spi), GFP_KERNEL);
 85	if (!async_spi)
 86		return NULL;
 87
 88	return &async_spi->core;
 89}
 90
 91static int regmap_spi_read(void *context,
 92			   const void *reg, size_t reg_size,
 93			   void *val, size_t val_size)
 94{
 95	struct device *dev = context;
 96	struct spi_device *spi = to_spi_device(dev);
 97
 98	return spi_write_then_read(spi, reg, reg_size, val, val_size);
 99}
100
101static const struct regmap_bus regmap_spi = {
 
102	.write = regmap_spi_write,
103	.gather_write = regmap_spi_gather_write,
104	.async_write = regmap_spi_async_write,
105	.async_alloc = regmap_spi_async_alloc,
106	.read = regmap_spi_read,
 
107	.read_flag_mask = 0x80,
108	.reg_format_endian_default = REGMAP_ENDIAN_BIG,
109	.val_format_endian_default = REGMAP_ENDIAN_BIG,
110};
111
112static const struct regmap_bus *regmap_get_spi_bus(struct spi_device *spi,
113						   const struct regmap_config *config)
114{
115	size_t max_size = spi_max_transfer_size(spi);
116	size_t max_msg_size, reg_reserve_size;
117	struct regmap_bus *bus;
118
119	if (max_size != SIZE_MAX) {
120		bus = kmemdup(&regmap_spi, sizeof(*bus), GFP_KERNEL);
121		if (!bus)
122			return ERR_PTR(-ENOMEM);
123
124		max_msg_size = spi_max_message_size(spi);
125		reg_reserve_size = (config->reg_bits + config->pad_bits) / BITS_PER_BYTE;
126		if (max_size + reg_reserve_size > max_msg_size)
127			max_size -= reg_reserve_size;
128
129		bus->free_on_exit = true;
130		bus->max_raw_read = max_size;
131		bus->max_raw_write = max_size;
132
133		return bus;
134	}
135
136	return &regmap_spi;
137}
138
139struct regmap *__regmap_init_spi(struct spi_device *spi,
140				 const struct regmap_config *config,
141				 struct lock_class_key *lock_key,
142				 const char *lock_name)
143{
144	const struct regmap_bus *bus = regmap_get_spi_bus(spi, config);
145
146	if (IS_ERR(bus))
147		return ERR_CAST(bus);
148
149	return __regmap_init(&spi->dev, bus, &spi->dev, config, lock_key, lock_name);
150}
151EXPORT_SYMBOL_GPL(__regmap_init_spi);
152
153struct regmap *__devm_regmap_init_spi(struct spi_device *spi,
154				      const struct regmap_config *config,
155				      struct lock_class_key *lock_key,
156				      const char *lock_name)
157{
158	const struct regmap_bus *bus = regmap_get_spi_bus(spi, config);
159
160	if (IS_ERR(bus))
161		return ERR_CAST(bus);
162
163	return __devm_regmap_init(&spi->dev, bus, &spi->dev, config, lock_key, lock_name);
164}
165EXPORT_SYMBOL_GPL(__devm_regmap_init_spi);
166
167MODULE_DESCRIPTION("regmap SPI Module");
168MODULE_LICENSE("GPL");