xref: /linux/drivers/mfd/rk8xx-spi.c (revision f4738f56d1dc62aaba69b33702a5ab098f1b8c63)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Rockchip RK806 Core (SPI) driver
4  *
5  * Copyright (c) 2021 Rockchip Electronics Co., Ltd.
6  * Copyright (c) 2023 Collabora Ltd.
7  *
8  * Author: Xu Shengfei <xsf@rock-chips.com>
9  * Author: Sebastian Reichel <sebastian.reichel@collabora.com>
10  */
11 
12 #include <linux/interrupt.h>
13 #include <linux/mfd/core.h>
14 #include <linux/mfd/rk808.h>
15 #include <linux/module.h>
16 #include <linux/regmap.h>
17 #include <linux/spi/spi.h>
18 
19 #define RK806_ADDR_SIZE 2
20 #define RK806_CMD_WITH_SIZE(CMD, VALUE_BYTES) \
21 	(RK806_CMD_##CMD | RK806_CMD_CRC_DIS | (VALUE_BYTES - 1))
22 
23 static const struct regmap_range rk806_volatile_ranges[] = {
24 	regmap_reg_range(RK806_POWER_EN0, RK806_POWER_EN5),
25 	regmap_reg_range(RK806_DVS_START_CTRL, RK806_INT_MSK1),
26 };
27 
28 static const struct regmap_access_table rk806_volatile_table = {
29 	.yes_ranges = rk806_volatile_ranges,
30 	.n_yes_ranges = ARRAY_SIZE(rk806_volatile_ranges),
31 };
32 
33 static const struct regmap_config rk806_regmap_config_spi = {
34 	.reg_bits = 16,
35 	.val_bits = 8,
36 	.max_register = RK806_BUCK_RSERVE_REG5,
37 	.cache_type = REGCACHE_RBTREE,
38 	.volatile_table = &rk806_volatile_table,
39 };
40 
41 static int rk806_spi_bus_write(void *context, const void *vdata, size_t count)
42 {
43 	struct device *dev = context;
44 	struct spi_device *spi = to_spi_device(dev);
45 	struct spi_transfer xfer[2] = { 0 };
46 	/* data and thus count includes the register address */
47 	size_t val_size = count - RK806_ADDR_SIZE;
48 	char cmd;
49 
50 	if (val_size < 1 || val_size > (RK806_CMD_LEN_MSK + 1))
51 		return -EINVAL;
52 
53 	cmd = RK806_CMD_WITH_SIZE(WRITE, val_size);
54 
55 	xfer[0].tx_buf = &cmd;
56 	xfer[0].len = sizeof(cmd);
57 	xfer[1].tx_buf = vdata;
58 	xfer[1].len = count;
59 
60 	return spi_sync_transfer(spi, xfer, ARRAY_SIZE(xfer));
61 }
62 
63 static int rk806_spi_bus_read(void *context, const void *vreg, size_t reg_size,
64 			      void *val, size_t val_size)
65 {
66 	struct device *dev = context;
67 	struct spi_device *spi = to_spi_device(dev);
68 	char txbuf[3] = { 0 };
69 
70 	if (reg_size != RK806_ADDR_SIZE ||
71 	    val_size < 1 || val_size > (RK806_CMD_LEN_MSK + 1))
72 		return -EINVAL;
73 
74 	/* TX buffer contains command byte followed by two address bytes */
75 	txbuf[0] = RK806_CMD_WITH_SIZE(READ, val_size);
76 	memcpy(txbuf+1, vreg, reg_size);
77 
78 	return spi_write_then_read(spi, txbuf, sizeof(txbuf), val, val_size);
79 }
80 
81 static const struct regmap_bus rk806_regmap_bus_spi = {
82 	.write = rk806_spi_bus_write,
83 	.read = rk806_spi_bus_read,
84 	.reg_format_endian_default = REGMAP_ENDIAN_LITTLE,
85 };
86 
87 static int rk8xx_spi_probe(struct spi_device *spi)
88 {
89 	struct regmap *regmap;
90 
91 	regmap = devm_regmap_init(&spi->dev, &rk806_regmap_bus_spi,
92 				  &spi->dev, &rk806_regmap_config_spi);
93 	if (IS_ERR(regmap))
94 		return dev_err_probe(&spi->dev, PTR_ERR(regmap),
95 				     "Failed to init regmap\n");
96 
97 	return rk8xx_probe(&spi->dev, RK806_ID, spi->irq, regmap);
98 }
99 
100 static const struct of_device_id rk8xx_spi_of_match[] = {
101 	{ .compatible = "rockchip,rk806", },
102 	{ }
103 };
104 MODULE_DEVICE_TABLE(of, rk8xx_spi_of_match);
105 
106 static const struct spi_device_id rk8xx_spi_id_table[] = {
107 	{ "rk806", 0 },
108 	{ }
109 };
110 MODULE_DEVICE_TABLE(spi, rk8xx_spi_id_table);
111 
112 static struct spi_driver rk8xx_spi_driver = {
113 	.driver		= {
114 		.name	= "rk8xx-spi",
115 		.of_match_table = rk8xx_spi_of_match,
116 	},
117 	.probe		= rk8xx_spi_probe,
118 	.id_table	= rk8xx_spi_id_table,
119 };
120 module_spi_driver(rk8xx_spi_driver);
121 
122 MODULE_AUTHOR("Xu Shengfei <xsf@rock-chips.com>");
123 MODULE_DESCRIPTION("RK8xx SPI PMIC driver");
124 MODULE_LICENSE("GPL");
125