1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * SPI access driver for the following TI PMICs:
4 * - LP8764
5 * - TPS65224
6 * - TPS652G1
7 * - TPS6593
8 * - TPS6594
9 *
10 * Copyright (C) 2023 BayLibre Incorporated - https://www.baylibre.com/
11 */
12
13 #include <linux/crc8.h>
14 #include <linux/module.h>
15 #include <linux/mod_devicetable.h>
16 #include <linux/of_device.h>
17 #include <linux/regmap.h>
18 #include <linux/spi/spi.h>
19
20 #include <linux/mfd/tps6594.h>
21
22 #define TPS6594_SPI_PAGE_SHIFT 5
23 #define TPS6594_SPI_READ_BIT BIT(4)
24
25 static bool enable_crc;
26 module_param(enable_crc, bool, 0444);
27 MODULE_PARM_DESC(enable_crc, "Enable CRC feature for SPI interface");
28
29 DECLARE_CRC8_TABLE(tps6594_spi_crc_table);
30
tps6594_spi_reg_read(void * context,unsigned int reg,unsigned int * val)31 static int tps6594_spi_reg_read(void *context, unsigned int reg, unsigned int *val)
32 {
33 struct spi_device *spi = context;
34 struct tps6594 *tps = spi_get_drvdata(spi);
35 u8 buf[4] = { 0 };
36 size_t count_rx = 1;
37 int ret;
38
39 buf[0] = reg;
40 buf[1] = TPS6594_REG_TO_PAGE(reg) << TPS6594_SPI_PAGE_SHIFT | TPS6594_SPI_READ_BIT;
41
42 if (tps->use_crc)
43 count_rx++;
44
45 ret = spi_write_then_read(spi, buf, 2, buf + 2, count_rx);
46 if (ret < 0)
47 return ret;
48
49 if (tps->use_crc && buf[3] != crc8(tps6594_spi_crc_table, buf, 3, CRC8_INIT_VALUE))
50 return -EIO;
51
52 *val = buf[2];
53
54 return 0;
55 }
56
tps6594_spi_reg_write(void * context,unsigned int reg,unsigned int val)57 static int tps6594_spi_reg_write(void *context, unsigned int reg, unsigned int val)
58 {
59 struct spi_device *spi = context;
60 struct tps6594 *tps = spi_get_drvdata(spi);
61 u8 buf[4] = { 0 };
62 size_t count = 3;
63
64 buf[0] = reg;
65 buf[1] = TPS6594_REG_TO_PAGE(reg) << TPS6594_SPI_PAGE_SHIFT;
66 buf[2] = val;
67
68 if (tps->use_crc)
69 buf[3] = crc8(tps6594_spi_crc_table, buf, count++, CRC8_INIT_VALUE);
70
71 return spi_write(spi, buf, count);
72 }
73
74 static struct regmap_config tps6594_spi_regmap_config = {
75 .reg_bits = 16,
76 .val_bits = 8,
77 .max_register = TPS6594_REG_DWD_FAIL_CNT_REG,
78 .volatile_table = &tps6594_volatile_table,
79 .reg_read = tps6594_spi_reg_read,
80 .reg_write = tps6594_spi_reg_write,
81 .use_single_read = true,
82 .use_single_write = true,
83 };
84
85 static const struct of_device_id tps6594_spi_of_match_table[] = {
86 { .compatible = "ti,tps6594-q1", .data = (void *)TPS6594, },
87 { .compatible = "ti,tps6593-q1", .data = (void *)TPS6593, },
88 { .compatible = "ti,lp8764-q1", .data = (void *)LP8764, },
89 { .compatible = "ti,tps65224-q1", .data = (void *)TPS65224, },
90 { .compatible = "ti,tps652g1", .data = (void *)TPS652G1, },
91 {}
92 };
93 MODULE_DEVICE_TABLE(of, tps6594_spi_of_match_table);
94
tps6594_spi_probe(struct spi_device * spi)95 static int tps6594_spi_probe(struct spi_device *spi)
96 {
97 struct device *dev = &spi->dev;
98 struct tps6594 *tps;
99 const struct of_device_id *match;
100
101 tps = devm_kzalloc(dev, sizeof(*tps), GFP_KERNEL);
102 if (!tps)
103 return -ENOMEM;
104
105 spi_set_drvdata(spi, tps);
106
107 tps->dev = dev;
108 tps->reg = spi_get_chipselect(spi, 0);
109 tps->irq = spi->irq;
110
111 match = of_match_device(tps6594_spi_of_match_table, dev);
112 if (!match)
113 return dev_err_probe(dev, -EINVAL, "Failed to find matching chip ID\n");
114 tps->chip_id = (unsigned long)match->data;
115
116 if (tps->chip_id == TPS65224 || tps->chip_id == TPS652G1)
117 tps6594_spi_regmap_config.volatile_table = &tps65224_volatile_table;
118
119 tps->regmap = devm_regmap_init(dev, NULL, spi, &tps6594_spi_regmap_config);
120 if (IS_ERR(tps->regmap))
121 return dev_err_probe(dev, PTR_ERR(tps->regmap), "Failed to init regmap\n");
122
123 crc8_populate_msb(tps6594_spi_crc_table, TPS6594_CRC8_POLYNOMIAL);
124
125 return tps6594_device_init(tps, enable_crc);
126 }
127
128 static struct spi_driver tps6594_spi_driver = {
129 .driver = {
130 .name = "tps6594",
131 .of_match_table = tps6594_spi_of_match_table,
132 },
133 .probe = tps6594_spi_probe,
134 };
135 module_spi_driver(tps6594_spi_driver);
136
137 MODULE_AUTHOR("Julien Panis <jpanis@baylibre.com>");
138 MODULE_DESCRIPTION("SPI Interface Driver for TPS65224, TPS6594/3, and LP8764");
139 MODULE_LICENSE("GPL");
140