forked from mirrors/linux
8786b095df
There are slave devices that understand I2C but have read-only SDA and SCL. Examples are FD650 7-segment LED controller and its derivatives. Typical board designs don't even have a pull-up for both pins. Handle the new attributes for write-only SDA and missing pull-up on SDA/SCL. For either pin the open-drain and has-no-pullup properties are mutually-exclusive, what is documented in the DT property documentation. We don't add an extra warning here because the open-drain properties are marked deprecated anyway. Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> [wsa: switched to device properties] Signed-off-by: Wolfram Sang <wsa@kernel.org>
40 lines
1.5 KiB
C
40 lines
1.5 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* i2c-gpio interface to platform code
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*
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* Copyright (C) 2007 Atmel Corporation
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*/
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#ifndef _LINUX_I2C_GPIO_H
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#define _LINUX_I2C_GPIO_H
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/**
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* struct i2c_gpio_platform_data - Platform-dependent data for i2c-gpio
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* @udelay: signal toggle delay. SCL frequency is (500 / udelay) kHz
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* @timeout: clock stretching timeout in jiffies. If the slave keeps
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* SCL low for longer than this, the transfer will time out.
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* @sda_is_open_drain: SDA is configured as open drain, i.e. the pin
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* isn't actively driven high when setting the output value high.
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* gpio_get_value() must return the actual pin state even if the
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* pin is configured as an output.
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* @sda_is_output_only: SDA output drivers can't be turned off.
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* This is for clients that can only read SDA/SCL.
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* @sda_has_no_pullup: SDA is used in a non-compliant way and has no pull-up.
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* Therefore disable open-drain.
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* @scl_is_open_drain: SCL is set up as open drain. Same requirements
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* as for sda_is_open_drain apply.
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* @scl_is_output_only: SCL output drivers cannot be turned off.
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* @scl_has_no_pullup: SCL is used in a non-compliant way and has no pull-up.
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* Therefore disable open-drain.
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*/
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struct i2c_gpio_platform_data {
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int udelay;
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int timeout;
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unsigned int sda_is_open_drain:1;
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unsigned int sda_is_output_only:1;
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unsigned int sda_has_no_pullup:1;
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unsigned int scl_is_open_drain:1;
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unsigned int scl_is_output_only:1;
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unsigned int scl_has_no_pullup:1;
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};
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#endif /* _LINUX_I2C_GPIO_H */
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