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c578728d2e
LM74 is a SPI temperature sensor. Implement a driver to read temperature from it. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
52 lines
875 B
C
52 lines
875 B
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* TI LM74 temperature sensor driver
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*
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* Copyright (C) 2024 CS GROUP France
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*
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*/
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#include <dm.h>
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#include <thermal.h>
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#include <spi.h>
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static int ti_lm74_get_temp(struct udevice *dev, int *temp)
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{
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char buf[2];
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s16 raw;
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int ret;
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ret = dm_spi_claim_bus(dev);
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if (ret)
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return ret;
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ret = dm_spi_xfer(dev, 16, NULL, buf, SPI_XFER_BEGIN | SPI_XFER_END);
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dm_spi_release_bus(dev);
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if (ret)
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return ret;
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raw = ((buf[0] << 8) + buf[1]) >> 3;
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*temp = (((int)raw * 125) + 1000) / 2000;
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return 0;
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}
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static struct dm_thermal_ops ti_lm74_ops = {
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.get_temp = ti_lm74_get_temp,
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};
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static const struct udevice_id of_ti_lm74_match[] = {
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{
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.compatible = "ti,lm74",
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},
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{},
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};
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U_BOOT_DRIVER(ti_bandgap_thermal) = {
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.name = "ti_lm74_thermal",
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.id = UCLASS_THERMAL,
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.ops = &ti_lm74_ops,
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.of_match = of_ti_lm74_match,
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};
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