104 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			104 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * Murata ZPA2326 SPI pressure and temperature sensor driver
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 *
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 * Copyright (c) 2016 Parrot S.A.
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 *
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 * Author: Gregor Boirie <gregor.boirie@parrot.com>
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 *
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 * This program is free software; you can redistribute it and/or modify it
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 * under the terms of the GNU General Public License version 2 as published by
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 * the Free Software Foundation.
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 *
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 * This program is distributed in the hope that it will be useful, but WITHOUT
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 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
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 * more details.
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 */
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#include <linux/module.h>
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#include <linux/regmap.h>
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#include <linux/spi/spi.h>
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#include <linux/of_device.h>
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#include "zpa2326.h"
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/*
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 * read_flag_mask:
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 *   - address bit 7 must be set to request a register read operation
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 *   - address bit 6 must be set to request register address auto increment
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 */
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static const struct regmap_config zpa2326_regmap_spi_config = {
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	.reg_bits       = 8,
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	.val_bits       = 8,
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	.writeable_reg  = zpa2326_isreg_writeable,
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	.readable_reg   = zpa2326_isreg_readable,
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	.precious_reg   = zpa2326_isreg_precious,
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	.max_register   = ZPA2326_TEMP_OUT_H_REG,
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	.read_flag_mask = BIT(7) | BIT(6),
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	.cache_type     = REGCACHE_NONE,
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};
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static int zpa2326_probe_spi(struct spi_device *spi)
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{
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	struct regmap *regmap;
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	int            err;
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	regmap = devm_regmap_init_spi(spi, &zpa2326_regmap_spi_config);
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	if (IS_ERR(regmap)) {
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		dev_err(&spi->dev, "failed to init registers map");
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		return PTR_ERR(regmap);
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	}
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	/*
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	 * Enforce SPI slave settings to prevent from DT misconfiguration.
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	 *
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	 * Clock is idle high. Sampling happens on trailing edge, i.e., rising
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	 * edge. Maximum bus frequency is 1 MHz. Registers are 8 bits wide.
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	 */
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	spi->mode = SPI_MODE_3;
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	spi->max_speed_hz = min(spi->max_speed_hz, 1000000U);
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	spi->bits_per_word = 8;
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	err = spi_setup(spi);
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	if (err < 0)
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		return err;
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	return zpa2326_probe(&spi->dev, spi_get_device_id(spi)->name,
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			     spi->irq, ZPA2326_DEVICE_ID, regmap);
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}
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static int zpa2326_remove_spi(struct spi_device *spi)
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{
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	zpa2326_remove(&spi->dev);
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	return 0;
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}
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static const struct spi_device_id zpa2326_spi_ids[] = {
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	{ "zpa2326", 0 },
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	{ },
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};
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MODULE_DEVICE_TABLE(spi, zpa2326_spi_ids);
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#if defined(CONFIG_OF)
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static const struct of_device_id zpa2326_spi_matches[] = {
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	{ .compatible = "murata,zpa2326" },
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	{ }
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};
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MODULE_DEVICE_TABLE(of, zpa2326_spi_matches);
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#endif
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static struct spi_driver zpa2326_spi_driver = {
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	.driver = {
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		.name           = "zpa2326-spi",
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		.of_match_table = of_match_ptr(zpa2326_spi_matches),
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		.pm             = ZPA2326_PM_OPS,
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	},
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	.probe    = zpa2326_probe_spi,
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	.remove   = zpa2326_remove_spi,
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	.id_table = zpa2326_spi_ids,
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};
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module_spi_driver(zpa2326_spi_driver);
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MODULE_AUTHOR("Gregor Boirie <gregor.boirie@parrot.com>");
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MODULE_DESCRIPTION("SPI driver for Murata ZPA2326 pressure sensor");
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MODULE_LICENSE("GPL v2");
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