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");