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