1/*
2 * Register map access API - SPMI support
3 *
4 * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
5 *
6 * Based on regmap-i2c.c:
7 * Copyright 2011 Wolfson Microelectronics plc
8 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 and
12 * only version 2 as published by the Free Software Foundation.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17 * GNU General Public License for more details.
18 *
19 */
20#include <linux/regmap.h>
21#include <linux/spmi.h>
22#include <linux/module.h>
23#include <linux/init.h>
24
25static int regmap_spmi_base_read(void *context,
26				 const void *reg, size_t reg_size,
27				 void *val, size_t val_size)
28{
29	u8 addr = *(u8 *)reg;
30	int err = 0;
31
32	BUG_ON(reg_size != 1);
33
34	while (val_size-- && !err)
35		err = spmi_register_read(context, addr++, val++);
36
37	return err;
38}
39
40static int regmap_spmi_base_gather_write(void *context,
41					 const void *reg, size_t reg_size,
42					 const void *val, size_t val_size)
43{
44	const u8 *data = val;
45	u8 addr = *(u8 *)reg;
46	int err = 0;
47
48	BUG_ON(reg_size != 1);
49
50	/*
51	 * SPMI defines a more bandwidth-efficient 'Register 0 Write' sequence,
52	 * use it when possible.
53	 */
54	if (addr == 0 && val_size) {
55		err = spmi_register_zero_write(context, *data);
56		if (err)
57			goto err_out;
58
59		data++;
60		addr++;
61		val_size--;
62	}
63
64	while (val_size) {
65		err = spmi_register_write(context, addr, *data);
66		if (err)
67			goto err_out;
68
69		data++;
70		addr++;
71		val_size--;
72	}
73
74err_out:
75	return err;
76}
77
78static int regmap_spmi_base_write(void *context, const void *data,
79				  size_t count)
80{
81	BUG_ON(count < 1);
82	return regmap_spmi_base_gather_write(context, data, 1, data + 1,
83					     count - 1);
84}
85
86static struct regmap_bus regmap_spmi_base = {
87	.read				= regmap_spmi_base_read,
88	.write				= regmap_spmi_base_write,
89	.gather_write			= regmap_spmi_base_gather_write,
90	.reg_format_endian_default	= REGMAP_ENDIAN_NATIVE,
91	.val_format_endian_default	= REGMAP_ENDIAN_NATIVE,
92};
93
94struct regmap *__regmap_init_spmi_base(struct spmi_device *sdev,
95				       const struct regmap_config *config,
96				       struct lock_class_key *lock_key,
97				       const char *lock_name)
98{
99	return __regmap_init(&sdev->dev, &regmap_spmi_base, sdev, config,
100			     lock_key, lock_name);
101}
102EXPORT_SYMBOL_GPL(__regmap_init_spmi_base);
103
104struct regmap *__devm_regmap_init_spmi_base(struct spmi_device *sdev,
105					    const struct regmap_config *config,
106					    struct lock_class_key *lock_key,
107					    const char *lock_name)
108{
109	return __devm_regmap_init(&sdev->dev, &regmap_spmi_base, sdev, config,
110				  lock_key, lock_name);
111}
112EXPORT_SYMBOL_GPL(__devm_regmap_init_spmi_base);
113
114static int regmap_spmi_ext_read(void *context,
115				const void *reg, size_t reg_size,
116				void *val, size_t val_size)
117{
118	int err = 0;
119	size_t len;
120	u16 addr;
121
122	BUG_ON(reg_size != 2);
123
124	addr = *(u16 *)reg;
125
126	/*
127	 * Split accesses into two to take advantage of the more
128	 * bandwidth-efficient 'Extended Register Read' command when possible
129	 */
130	while (addr <= 0xFF && val_size) {
131		len = min_t(size_t, val_size, 16);
132
133		err = spmi_ext_register_read(context, addr, val, len);
134		if (err)
135			goto err_out;
136
137		addr += len;
138		val += len;
139		val_size -= len;
140	}
141
142	while (val_size) {
143		len = min_t(size_t, val_size, 8);
144
145		err = spmi_ext_register_readl(context, addr, val, len);
146		if (err)
147			goto err_out;
148
149		addr += len;
150		val += len;
151		val_size -= len;
152	}
153
154err_out:
155	return err;
156}
157
158static int regmap_spmi_ext_gather_write(void *context,
159					const void *reg, size_t reg_size,
160					const void *val, size_t val_size)
161{
162	int err = 0;
163	size_t len;
164	u16 addr;
165
166	BUG_ON(reg_size != 2);
167
168	addr = *(u16 *)reg;
169
170	while (addr <= 0xFF && val_size) {
171		len = min_t(size_t, val_size, 16);
172
173		err = spmi_ext_register_write(context, addr, val, len);
174		if (err)
175			goto err_out;
176
177		addr += len;
178		val += len;
179		val_size -= len;
180	}
181
182	while (val_size) {
183		len = min_t(size_t, val_size, 8);
184
185		err = spmi_ext_register_writel(context, addr, val, len);
186		if (err)
187			goto err_out;
188
189		addr += len;
190		val += len;
191		val_size -= len;
192	}
193
194err_out:
195	return err;
196}
197
198static int regmap_spmi_ext_write(void *context, const void *data,
199				 size_t count)
200{
201	BUG_ON(count < 2);
202	return regmap_spmi_ext_gather_write(context, data, 2, data + 2,
203					    count - 2);
204}
205
206static struct regmap_bus regmap_spmi_ext = {
207	.read				= regmap_spmi_ext_read,
208	.write				= regmap_spmi_ext_write,
209	.gather_write			= regmap_spmi_ext_gather_write,
210	.reg_format_endian_default	= REGMAP_ENDIAN_NATIVE,
211	.val_format_endian_default	= REGMAP_ENDIAN_NATIVE,
212};
213
214struct regmap *__regmap_init_spmi_ext(struct spmi_device *sdev,
215				      const struct regmap_config *config,
216				      struct lock_class_key *lock_key,
217				      const char *lock_name)
218{
219	return __regmap_init(&sdev->dev, &regmap_spmi_ext, sdev, config,
220			     lock_key, lock_name);
221}
222EXPORT_SYMBOL_GPL(__regmap_init_spmi_ext);
223
224struct regmap *__devm_regmap_init_spmi_ext(struct spmi_device *sdev,
225					   const struct regmap_config *config,
226					   struct lock_class_key *lock_key,
227					   const char *lock_name)
228{
229	return __devm_regmap_init(&sdev->dev, &regmap_spmi_ext, sdev, config,
230				  lock_key, lock_name);
231}
232EXPORT_SYMBOL_GPL(__devm_regmap_init_spmi_ext);
233
234MODULE_LICENSE("GPL");
235