1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * ADGS1408/ADGS1409 SPI MUX driver 4 * 5 * Copyright 2018 Analog Devices Inc. 6 */ 7 8 #include <linux/err.h> 9 #include <linux/module.h> 10 #include <linux/mux/driver.h> 11 #include <linux/of_platform.h> 12 #include <linux/property.h> 13 #include <linux/spi/spi.h> 14 15 #define ADGS1408_SW_DATA (0x01) 16 #define ADGS1408_REG_READ(reg) ((reg) | 0x80) 17 #define ADGS1408_DISABLE (0x00) 18 #define ADGS1408_MUX(state) (((state) << 1) | 1) 19 20 enum adgs1408_chip_id { 21 ADGS1408 = 1, 22 ADGS1409, 23 }; 24 25 static int adgs1408_spi_reg_write(struct spi_device *spi, 26 u8 reg_addr, u8 reg_data) 27 { 28 u8 tx_buf[2]; 29 30 tx_buf[0] = reg_addr; 31 tx_buf[1] = reg_data; 32 33 return spi_write_then_read(spi, tx_buf, sizeof(tx_buf), NULL, 0); 34 } 35 36 static int adgs1408_set(struct mux_control *mux, int state) 37 { 38 struct spi_device *spi = to_spi_device(mux->chip->dev.parent); 39 u8 reg; 40 41 if (state == MUX_IDLE_DISCONNECT) 42 reg = ADGS1408_DISABLE; 43 else 44 reg = ADGS1408_MUX(state); 45 46 return adgs1408_spi_reg_write(spi, ADGS1408_SW_DATA, reg); 47 } 48 49 static const struct mux_control_ops adgs1408_ops = { 50 .set = adgs1408_set, 51 }; 52 53 static int adgs1408_probe(struct spi_device *spi) 54 { 55 struct device *dev = &spi->dev; 56 enum adgs1408_chip_id chip_id; 57 struct mux_chip *mux_chip; 58 struct mux_control *mux; 59 s32 idle_state; 60 int ret; 61 62 chip_id = (enum adgs1408_chip_id)of_device_get_match_data(dev); 63 if (!chip_id) 64 chip_id = spi_get_device_id(spi)->driver_data; 65 66 mux_chip = devm_mux_chip_alloc(dev, 1, 0); 67 if (IS_ERR(mux_chip)) 68 return PTR_ERR(mux_chip); 69 70 mux_chip->ops = &adgs1408_ops; 71 72 ret = adgs1408_spi_reg_write(spi, ADGS1408_SW_DATA, ADGS1408_DISABLE); 73 if (ret < 0) 74 return ret; 75 76 ret = device_property_read_u32(dev, "idle-state", (u32 *)&idle_state); 77 if (ret < 0) 78 idle_state = MUX_IDLE_AS_IS; 79 80 mux = mux_chip->mux; 81 82 if (chip_id == ADGS1408) 83 mux->states = 8; 84 else 85 mux->states = 4; 86 87 switch (idle_state) { 88 case MUX_IDLE_DISCONNECT: 89 case MUX_IDLE_AS_IS: 90 case 0 ... 7: 91 /* adgs1409 supports only 4 states */ 92 if (idle_state < mux->states) { 93 mux->idle_state = idle_state; 94 break; 95 } 96 /* fall through */ 97 default: 98 dev_err(dev, "invalid idle-state %d\n", idle_state); 99 return -EINVAL; 100 } 101 102 return devm_mux_chip_register(dev, mux_chip); 103 } 104 105 static const struct spi_device_id adgs1408_spi_id[] = { 106 { "adgs1408", ADGS1408 }, 107 { "adgs1409", ADGS1409 }, 108 { } 109 }; 110 MODULE_DEVICE_TABLE(spi, adgs1408_spi_id); 111 112 static const struct of_device_id adgs1408_of_match[] = { 113 { .compatible = "adi,adgs1408", .data = (void *)ADGS1408, }, 114 { .compatible = "adi,adgs1409", .data = (void *)ADGS1409, }, 115 { } 116 }; 117 MODULE_DEVICE_TABLE(of, adgs1408_of_match); 118 119 static struct spi_driver adgs1408_driver = { 120 .driver = { 121 .name = "adgs1408", 122 .of_match_table = of_match_ptr(adgs1408_of_match), 123 }, 124 .probe = adgs1408_probe, 125 .id_table = adgs1408_spi_id, 126 }; 127 module_spi_driver(adgs1408_driver); 128 129 MODULE_AUTHOR("Mircea Caprioru <mircea.caprioru@analog.com>"); 130 MODULE_DESCRIPTION("Analog Devices ADGS1408 MUX driver"); 131 MODULE_LICENSE("GPL"); 132