1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * STMicroelectronics sensors spi library driver 4 * 5 * Copyright 2012-2013 STMicroelectronics Inc. 6 * 7 * Denis Ciocca <denis.ciocca@st.com> 8 */ 9 10 #include <linux/kernel.h> 11 #include <linux/module.h> 12 #include <linux/slab.h> 13 #include <linux/iio/iio.h> 14 #include <linux/property.h> 15 #include <linux/regmap.h> 16 17 #include <linux/iio/common/st_sensors_spi.h> 18 #include "st_sensors_core.h" 19 20 #define ST_SENSORS_SPI_MULTIREAD 0xc0 21 22 static const struct regmap_config st_sensors_spi_regmap_config = { 23 .reg_bits = 8, 24 .val_bits = 8, 25 }; 26 27 static const struct regmap_config st_sensors_spi_regmap_multiread_bit_config = { 28 .reg_bits = 8, 29 .val_bits = 8, 30 .read_flag_mask = ST_SENSORS_SPI_MULTIREAD, 31 }; 32 33 /* 34 * st_sensors_is_spi_3_wire() - check if SPI 3-wire mode has been selected 35 * @spi: spi device reference. 36 * 37 * Return: true if SPI 3-wire mode is selected, false otherwise. 38 */ 39 static bool st_sensors_is_spi_3_wire(struct spi_device *spi) 40 { 41 struct st_sensors_platform_data *pdata; 42 struct device *dev = &spi->dev; 43 44 if (device_property_read_bool(dev, "spi-3wire")) 45 return true; 46 47 pdata = dev_get_platdata(dev); 48 if (pdata && pdata->spi_3wire) 49 return true; 50 51 return false; 52 } 53 54 /* 55 * st_sensors_configure_spi_3_wire() - configure SPI 3-wire if needed 56 * @spi: spi device reference. 57 * @settings: sensor specific settings reference. 58 * 59 * Return: 0 on success, else a negative error code. 60 */ 61 static int st_sensors_configure_spi_3_wire(struct spi_device *spi, 62 struct st_sensor_settings *settings) 63 { 64 if (settings->sim.addr) { 65 u8 buffer[] = { 66 settings->sim.addr, 67 settings->sim.value 68 }; 69 70 return spi_write(spi, buffer, 2); 71 } 72 73 return 0; 74 } 75 76 /* 77 * st_sensors_spi_configure() - configure SPI interface 78 * @indio_dev: IIO device reference. 79 * @spi: spi device reference. 80 * 81 * Return: 0 on success, else a negative error code. 82 */ 83 int st_sensors_spi_configure(struct iio_dev *indio_dev, 84 struct spi_device *spi) 85 { 86 struct st_sensor_data *sdata = iio_priv(indio_dev); 87 const struct regmap_config *config; 88 int err; 89 90 if (st_sensors_is_spi_3_wire(spi)) { 91 err = st_sensors_configure_spi_3_wire(spi, 92 sdata->sensor_settings); 93 if (err < 0) 94 return err; 95 } 96 97 if (sdata->sensor_settings->multi_read_bit) 98 config = &st_sensors_spi_regmap_multiread_bit_config; 99 else 100 config = &st_sensors_spi_regmap_config; 101 102 sdata->regmap = devm_regmap_init_spi(spi, config); 103 if (IS_ERR(sdata->regmap)) { 104 dev_err(&spi->dev, "Failed to register spi regmap (%ld)\n", 105 PTR_ERR(sdata->regmap)); 106 return PTR_ERR(sdata->regmap); 107 } 108 109 spi_set_drvdata(spi, indio_dev); 110 111 indio_dev->name = spi->modalias; 112 113 sdata->dev = &spi->dev; 114 sdata->irq = spi->irq; 115 116 return 0; 117 } 118 EXPORT_SYMBOL(st_sensors_spi_configure); 119 120 MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>"); 121 MODULE_DESCRIPTION("STMicroelectronics ST-sensors spi driver"); 122 MODULE_LICENSE("GPL v2"); 123