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 
25 static 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 
40 static 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 
74 err_out:
75 	return err;
76 }
77 
78 static 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 
86 static 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 
94 /**
95  * regmap_init_spmi_base(): Create regmap for the Base register space
96  * @sdev:	SPMI device that will be interacted with
97  * @config:	Configuration for register map
98  *
99  * The return value will be an ERR_PTR() on error or a valid pointer to
100  * a struct regmap.
101  */
102 struct regmap *regmap_init_spmi_base(struct spmi_device *sdev,
103 				     const struct regmap_config *config)
104 {
105 	return regmap_init(&sdev->dev, &regmap_spmi_base, sdev, config);
106 }
107 EXPORT_SYMBOL_GPL(regmap_init_spmi_base);
108 
109 /**
110  * devm_regmap_init_spmi_base(): Create managed regmap for Base register space
111  * @sdev:	SPMI device that will be interacted with
112  * @config:	Configuration for register map
113  *
114  * The return value will be an ERR_PTR() on error or a valid pointer
115  * to a struct regmap.  The regmap will be automatically freed by the
116  * device management code.
117  */
118 struct regmap *devm_regmap_init_spmi_base(struct spmi_device *sdev,
119 					  const struct regmap_config *config)
120 {
121 	return devm_regmap_init(&sdev->dev, &regmap_spmi_base, sdev, config);
122 }
123 EXPORT_SYMBOL_GPL(devm_regmap_init_spmi_base);
124 
125 static int regmap_spmi_ext_read(void *context,
126 				const void *reg, size_t reg_size,
127 				void *val, size_t val_size)
128 {
129 	int err = 0;
130 	size_t len;
131 	u16 addr;
132 
133 	BUG_ON(reg_size != 2);
134 
135 	addr = *(u16 *)reg;
136 
137 	/*
138 	 * Split accesses into two to take advantage of the more
139 	 * bandwidth-efficient 'Extended Register Read' command when possible
140 	 */
141 	while (addr <= 0xFF && val_size) {
142 		len = min_t(size_t, val_size, 16);
143 
144 		err = spmi_ext_register_read(context, addr, val, len);
145 		if (err)
146 			goto err_out;
147 
148 		addr += len;
149 		val += len;
150 		val_size -= len;
151 	}
152 
153 	while (val_size) {
154 		len = min_t(size_t, val_size, 8);
155 
156 		err = spmi_ext_register_readl(context, addr, val, val_size);
157 		if (err)
158 			goto err_out;
159 
160 		addr += len;
161 		val += len;
162 		val_size -= len;
163 	}
164 
165 err_out:
166 	return err;
167 }
168 
169 static int regmap_spmi_ext_gather_write(void *context,
170 					const void *reg, size_t reg_size,
171 					const void *val, size_t val_size)
172 {
173 	int err = 0;
174 	size_t len;
175 	u16 addr;
176 
177 	BUG_ON(reg_size != 2);
178 
179 	addr = *(u16 *)reg;
180 
181 	while (addr <= 0xFF && val_size) {
182 		len = min_t(size_t, val_size, 16);
183 
184 		err = spmi_ext_register_write(context, addr, val, len);
185 		if (err)
186 			goto err_out;
187 
188 		addr += len;
189 		val += len;
190 		val_size -= len;
191 	}
192 
193 	while (val_size) {
194 		len = min_t(size_t, val_size, 8);
195 
196 		err = spmi_ext_register_writel(context, addr, val, len);
197 		if (err)
198 			goto err_out;
199 
200 		addr += len;
201 		val += len;
202 		val_size -= len;
203 	}
204 
205 err_out:
206 	return err;
207 }
208 
209 static int regmap_spmi_ext_write(void *context, const void *data,
210 				 size_t count)
211 {
212 	BUG_ON(count < 2);
213 	return regmap_spmi_ext_gather_write(context, data, 2, data + 2,
214 					    count - 2);
215 }
216 
217 static struct regmap_bus regmap_spmi_ext = {
218 	.read				= regmap_spmi_ext_read,
219 	.write				= regmap_spmi_ext_write,
220 	.gather_write			= regmap_spmi_ext_gather_write,
221 	.reg_format_endian_default	= REGMAP_ENDIAN_NATIVE,
222 	.val_format_endian_default	= REGMAP_ENDIAN_NATIVE,
223 };
224 
225 /**
226  * regmap_init_spmi_ext(): Create regmap for Ext register space
227  * @sdev:	Device that will be interacted with
228  * @config:	Configuration for register map
229  *
230  * The return value will be an ERR_PTR() on error or a valid pointer to
231  * a struct regmap.
232  */
233 struct regmap *regmap_init_spmi_ext(struct spmi_device *sdev,
234 				    const struct regmap_config *config)
235 {
236 	return regmap_init(&sdev->dev, &regmap_spmi_ext, sdev, config);
237 }
238 EXPORT_SYMBOL_GPL(regmap_init_spmi_ext);
239 
240 /**
241  * devm_regmap_init_spmi_ext(): Create managed regmap for Ext register space
242  * @sdev:	SPMI device that will be interacted with
243  * @config:	Configuration for register map
244  *
245  * The return value will be an ERR_PTR() on error or a valid pointer
246  * to a struct regmap.  The regmap will be automatically freed by the
247  * device management code.
248  */
249 struct regmap *devm_regmap_init_spmi_ext(struct spmi_device *sdev,
250 				     const struct regmap_config *config)
251 {
252 	return devm_regmap_init(&sdev->dev, &regmap_spmi_ext, sdev, config);
253 }
254 EXPORT_SYMBOL_GPL(devm_regmap_init_spmi_ext);
255 
256 MODULE_LICENSE("GPL");
257