1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Murata ZPA2326 SPI pressure and temperature sensor driver 4 * 5 * Copyright (c) 2016 Parrot S.A. 6 * 7 * Author: Gregor Boirie <gregor.boirie@parrot.com> 8 */ 9 10 #include <linux/module.h> 11 #include <linux/regmap.h> 12 #include <linux/spi/spi.h> 13 #include <linux/of_device.h> 14 #include "zpa2326.h" 15 16 /* 17 * read_flag_mask: 18 * - address bit 7 must be set to request a register read operation 19 * - address bit 6 must be set to request register address auto increment 20 */ 21 static const struct regmap_config zpa2326_regmap_spi_config = { 22 .reg_bits = 8, 23 .val_bits = 8, 24 .writeable_reg = zpa2326_isreg_writeable, 25 .readable_reg = zpa2326_isreg_readable, 26 .precious_reg = zpa2326_isreg_precious, 27 .max_register = ZPA2326_TEMP_OUT_H_REG, 28 .read_flag_mask = BIT(7) | BIT(6), 29 .cache_type = REGCACHE_NONE, 30 }; 31 32 static int zpa2326_probe_spi(struct spi_device *spi) 33 { 34 struct regmap *regmap; 35 int err; 36 37 regmap = devm_regmap_init_spi(spi, &zpa2326_regmap_spi_config); 38 if (IS_ERR(regmap)) { 39 dev_err(&spi->dev, "failed to init registers map"); 40 return PTR_ERR(regmap); 41 } 42 43 /* 44 * Enforce SPI slave settings to prevent from DT misconfiguration. 45 * 46 * Clock is idle high. Sampling happens on trailing edge, i.e., rising 47 * edge. Maximum bus frequency is 1 MHz. Registers are 8 bits wide. 48 */ 49 spi->mode = SPI_MODE_3; 50 spi->max_speed_hz = min(spi->max_speed_hz, 1000000U); 51 spi->bits_per_word = 8; 52 err = spi_setup(spi); 53 if (err < 0) 54 return err; 55 56 return zpa2326_probe(&spi->dev, spi_get_device_id(spi)->name, 57 spi->irq, ZPA2326_DEVICE_ID, regmap); 58 } 59 60 static int zpa2326_remove_spi(struct spi_device *spi) 61 { 62 zpa2326_remove(&spi->dev); 63 64 return 0; 65 } 66 67 static const struct spi_device_id zpa2326_spi_ids[] = { 68 { "zpa2326", 0 }, 69 { }, 70 }; 71 MODULE_DEVICE_TABLE(spi, zpa2326_spi_ids); 72 73 #if defined(CONFIG_OF) 74 static const struct of_device_id zpa2326_spi_matches[] = { 75 { .compatible = "murata,zpa2326" }, 76 { } 77 }; 78 MODULE_DEVICE_TABLE(of, zpa2326_spi_matches); 79 #endif 80 81 static struct spi_driver zpa2326_spi_driver = { 82 .driver = { 83 .name = "zpa2326-spi", 84 .of_match_table = of_match_ptr(zpa2326_spi_matches), 85 .pm = ZPA2326_PM_OPS, 86 }, 87 .probe = zpa2326_probe_spi, 88 .remove = zpa2326_remove_spi, 89 .id_table = zpa2326_spi_ids, 90 }; 91 module_spi_driver(zpa2326_spi_driver); 92 93 MODULE_AUTHOR("Gregor Boirie <gregor.boirie@parrot.com>"); 94 MODULE_DESCRIPTION("SPI driver for Murata ZPA2326 pressure sensor"); 95 MODULE_LICENSE("GPL v2"); 96