xref: /openbmc/linux/drivers/misc/ad525x_dpot-spi.c (revision 4f2c0a4acffbec01079c28f839422e64ddeff004)
1  // SPDX-License-Identifier: GPL-2.0-or-later
2  /*
3   * Driver for the Analog Devices digital potentiometers (SPI bus)
4   *
5   * Copyright (C) 2010-2011 Michael Hennerich, Analog Devices Inc.
6   */
7  
8  #include <linux/spi/spi.h>
9  #include <linux/module.h>
10  
11  #include "ad525x_dpot.h"
12  
13  /* SPI bus functions */
write8(void * client,u8 val)14  static int write8(void *client, u8 val)
15  {
16  	u8 data = val;
17  
18  	return spi_write(client, &data, 1);
19  }
20  
write16(void * client,u8 reg,u8 val)21  static int write16(void *client, u8 reg, u8 val)
22  {
23  	u8 data[2] = {reg, val};
24  
25  	return spi_write(client, data, 2);
26  }
27  
write24(void * client,u8 reg,u16 val)28  static int write24(void *client, u8 reg, u16 val)
29  {
30  	u8 data[3] = {reg, val >> 8, val};
31  
32  	return spi_write(client, data, 3);
33  }
34  
read8(void * client)35  static int read8(void *client)
36  {
37  	int ret;
38  	u8 data;
39  
40  	ret = spi_read(client, &data, 1);
41  	if (ret < 0)
42  		return ret;
43  
44  	return data;
45  }
46  
read16(void * client,u8 reg)47  static int read16(void *client, u8 reg)
48  {
49  	int ret;
50  	u8 buf_rx[2];
51  
52  	write16(client, reg, 0);
53  	ret = spi_read(client, buf_rx, 2);
54  	if (ret < 0)
55  		return ret;
56  
57  	return (buf_rx[0] << 8) |  buf_rx[1];
58  }
59  
read24(void * client,u8 reg)60  static int read24(void *client, u8 reg)
61  {
62  	int ret;
63  	u8 buf_rx[3];
64  
65  	write24(client, reg, 0);
66  	ret = spi_read(client, buf_rx, 3);
67  	if (ret < 0)
68  		return ret;
69  
70  	return (buf_rx[1] << 8) |  buf_rx[2];
71  }
72  
73  static const struct ad_dpot_bus_ops bops = {
74  	.read_d8	= read8,
75  	.read_r8d8	= read16,
76  	.read_r8d16	= read24,
77  	.write_d8	= write8,
78  	.write_r8d8	= write16,
79  	.write_r8d16	= write24,
80  };
ad_dpot_spi_probe(struct spi_device * spi)81  static int ad_dpot_spi_probe(struct spi_device *spi)
82  {
83  	struct ad_dpot_bus_data bdata = {
84  		.client = spi,
85  		.bops = &bops,
86  	};
87  
88  	return ad_dpot_probe(&spi->dev, &bdata,
89  			     spi_get_device_id(spi)->driver_data,
90  			     spi_get_device_id(spi)->name);
91  }
92  
ad_dpot_spi_remove(struct spi_device * spi)93  static void ad_dpot_spi_remove(struct spi_device *spi)
94  {
95  	ad_dpot_remove(&spi->dev);
96  }
97  
98  static const struct spi_device_id ad_dpot_spi_id[] = {
99  	{"ad5160", AD5160_ID},
100  	{"ad5161", AD5161_ID},
101  	{"ad5162", AD5162_ID},
102  	{"ad5165", AD5165_ID},
103  	{"ad5200", AD5200_ID},
104  	{"ad5201", AD5201_ID},
105  	{"ad5203", AD5203_ID},
106  	{"ad5204", AD5204_ID},
107  	{"ad5206", AD5206_ID},
108  	{"ad5207", AD5207_ID},
109  	{"ad5231", AD5231_ID},
110  	{"ad5232", AD5232_ID},
111  	{"ad5233", AD5233_ID},
112  	{"ad5235", AD5235_ID},
113  	{"ad5260", AD5260_ID},
114  	{"ad5262", AD5262_ID},
115  	{"ad5263", AD5263_ID},
116  	{"ad5290", AD5290_ID},
117  	{"ad5291", AD5291_ID},
118  	{"ad5292", AD5292_ID},
119  	{"ad5293", AD5293_ID},
120  	{"ad7376", AD7376_ID},
121  	{"ad8400", AD8400_ID},
122  	{"ad8402", AD8402_ID},
123  	{"ad8403", AD8403_ID},
124  	{"adn2850", ADN2850_ID},
125  	{"ad5270", AD5270_ID},
126  	{"ad5271", AD5271_ID},
127  	{}
128  };
129  MODULE_DEVICE_TABLE(spi, ad_dpot_spi_id);
130  
131  static struct spi_driver ad_dpot_spi_driver = {
132  	.driver = {
133  		.name	= "ad_dpot",
134  	},
135  	.probe		= ad_dpot_spi_probe,
136  	.remove		= ad_dpot_spi_remove,
137  	.id_table	= ad_dpot_spi_id,
138  };
139  
140  module_spi_driver(ad_dpot_spi_driver);
141  
142  MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
143  MODULE_DESCRIPTION("digital potentiometer SPI bus driver");
144  MODULE_LICENSE("GPL");
145  MODULE_ALIAS("spi:ad_dpot");
146