1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * SPI access driver for rockchip rk806
4 *
5 * Copyright (c) 2021 Rockchip Electronics Co., Ltd.
6 *
7 * Author: Xu Shengfei <xsf@rock-chips.com>
8 */
9
10 #include <linux/mfd/rk806.h>
11 #include <linux/module.h>
12 #include <linux/regmap.h>
13 #include <linux/spi/spi.h>
14
15 static const struct of_device_id rk806_spi_of_match_table[] = {
16 { .compatible = "rockchip,rk806", },
17 { }
18 };
19 MODULE_DEVICE_TABLE(of, rk806_spi_of_match_table);
20
rk806_spi_write(struct spi_device * spi,char addr,const char * data,size_t data_len)21 static int rk806_spi_write(struct spi_device *spi,
22 char addr,
23 const char *data,
24 size_t data_len)
25 {
26 char write_cmd = RK806_CMD_WRITE | (data_len - 1);
27 char addrh = RK806_REG_H;
28 struct spi_message m;
29 int buffer, ret = 0;
30 struct spi_transfer write_cmd_packet = {
31 .tx_buf = &buffer,
32 .len = sizeof(buffer),
33 };
34
35 buffer = write_cmd | (addr << 8) | (addrh << 16) | (*data << 24);
36
37 spi_message_init(&m);
38 spi_message_add_tail(&write_cmd_packet, &m);
39 ret = spi_sync(spi, &m);
40 return ret;
41 }
42
rk806_spi_bus_write(void * context,const void * data,size_t count)43 static int rk806_spi_bus_write(void *context, const void *data, size_t count)
44 {
45 struct device *dev = context;
46 struct spi_device *spi = to_spi_device(dev);
47 char buf[2];
48
49 if (count < 2) {
50 dev_err(&spi->dev, "regmap write err!\n");
51 return -EINVAL;
52 }
53 memcpy(buf, data, 2);
54
55 return rk806_spi_write(spi, buf[0], &buf[1], (count - 1));
56 }
57
rk806_spi_bus_read(void * context,const void * reg,size_t reg_size,void * val,size_t val_size)58 static int rk806_spi_bus_read(void *context,
59 const void *reg,
60 size_t reg_size,
61 void *val,
62 size_t val_size)
63 {
64 struct device *dev = context;
65 struct spi_device *spi = to_spi_device(dev);
66 char addr;
67 char txbuf[3] = { 0 };
68
69 if (reg_size != sizeof(char) || val_size < 1)
70 return -EINVAL;
71
72 /* Copy address to read from into first element of SPI buffer. */
73 memcpy(&addr, reg, sizeof(char));
74
75 txbuf[0] = RK806_CMD_READ | (val_size - 1);
76 txbuf[1] = addr;
77 txbuf[2] = RK806_REG_H;
78
79 return spi_write_then_read(spi, txbuf, 3, val, val_size);
80 }
81
82 static const struct regmap_bus rk806_regmap_bus_spi = {
83 .write = rk806_spi_bus_write,
84 .read = rk806_spi_bus_read,
85 .reg_format_endian_default = REGMAP_ENDIAN_NATIVE,
86 .val_format_endian_default = REGMAP_ENDIAN_NATIVE,
87 };
88
rk806_spi_probe(struct spi_device * spi)89 static int rk806_spi_probe(struct spi_device *spi)
90 {
91 struct rk806 *rk806;
92
93 rk806 = devm_kzalloc(&spi->dev, sizeof(*rk806), GFP_KERNEL);
94 if (!rk806)
95 return -ENOMEM;
96
97 spi_set_drvdata(spi, rk806);
98 rk806->dev = &spi->dev;
99 rk806->irq = spi->irq;
100
101 rk806->regmap = devm_regmap_init(&spi->dev,
102 &rk806_regmap_bus_spi,
103 &spi->dev,
104 &rk806_regmap_config_spi);
105 if (IS_ERR(rk806->regmap)) {
106 dev_err(rk806->dev, "Failed to initialize register map\n");
107 return PTR_ERR(rk806->regmap);
108 }
109
110 return rk806_device_init(rk806);
111 }
112
rk806_spi_remove(struct spi_device * spi)113 static int rk806_spi_remove(struct spi_device *spi)
114 {
115 struct rk806 *rk806 = spi_get_drvdata(spi);
116
117 return rk806_device_exit(rk806);
118 }
119
120 static const struct spi_device_id rk806_spi_id_table[] = {
121 { "rk806", 0 },
122 { /* sentinel */ }
123 };
124 MODULE_DEVICE_TABLE(spi, rk806_spi_id_table);
125
126 static struct spi_driver rk806_spi_driver = {
127 .driver = {
128 .name = "rk806",
129 .owner = THIS_MODULE,
130 .of_match_table = rk806_spi_of_match_table,
131 },
132 .probe = rk806_spi_probe,
133 .remove = rk806_spi_remove,
134 .id_table = rk806_spi_id_table,
135 };
136 module_spi_driver(rk806_spi_driver);
137
138 MODULE_AUTHOR("Xu Shengfei <xsf@rock-chips.com>");
139 MODULE_DESCRIPTION("RK806 SPI Interface Driver");
140 MODULE_LICENSE("GPL v2");
141