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