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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * ADGS1408/ADGS1409 SPI MUX driver4 *5 * Copyright 2018 Analog Devices Inc.6 */7 8#include <linux/err.h>9#include <linux/mod_devicetable.h>10#include <linux/module.h>11#include <linux/mux/driver.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 20enum adgs1408_chip_id {21 ADGS1408 = 1,22 ADGS1409,23};24 25static 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 36static 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 else44 reg = ADGS1408_MUX(state);45 46 return adgs1408_spi_reg_write(spi, ADGS1408_SW_DATA, reg);47}48 49static const struct mux_control_ops adgs1408_ops = {50 .set = adgs1408_set,51};52 53static 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)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 else85 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 fallthrough;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 105static const struct spi_device_id adgs1408_spi_id[] = {106 { "adgs1408", ADGS1408 },107 { "adgs1409", ADGS1409 },108 { }109};110MODULE_DEVICE_TABLE(spi, adgs1408_spi_id);111 112static const struct of_device_id adgs1408_of_match[] = {113 { .compatible = "adi,adgs1408", .data = (void *)ADGS1408, },114 { .compatible = "adi,adgs1409", .data = (void *)ADGS1409, },115 { }116};117MODULE_DEVICE_TABLE(of, adgs1408_of_match);118 119static struct spi_driver adgs1408_driver = {120 .driver = {121 .name = "adgs1408",122 .of_match_table = adgs1408_of_match,123 },124 .probe = adgs1408_probe,125 .id_table = adgs1408_spi_id,126};127module_spi_driver(adgs1408_driver);128 129MODULE_AUTHOR("Mircea Caprioru <mircea.caprioru@analog.com>");130MODULE_DESCRIPTION("Analog Devices ADGS1408 MUX driver");131MODULE_LICENSE("GPL");132