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5affb60772
Replace the arbitrary software-reset call from the device-probe method, because: - It is defective. To work correctly, it should be two byte writes, not a single word write. As it stands, it does nothing. - Some devices with sx150x expanders installed have their NRESET pins ganged on the same line, so resetting one causes the others to reset - not a nice thing to do arbitrarily! - The probe, usually taking place at boot, implies a recent hard-reset, so a software reset at this point is just a waste of energy anyway. Therefore, make it optional, defaulting to off, as this will match the common case of probing at powerup and also matches the current broken no-op behavior. Signed-off-by: Gregory Bean <gbean@codeaurora.org> Reviewed-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
83 lines
4.1 KiB
C
83 lines
4.1 KiB
C
/*
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* Driver for the Semtech SX150x I2C GPIO Expanders
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*
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* Copyright (c) 2010, Code Aurora Forum. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 and
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* only version 2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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* 02110-1301, USA.
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*/
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#ifndef __LINUX_I2C_SX150X_H
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#define __LINUX_I2C_SX150X_H
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/**
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* struct sx150x_platform_data - config data for SX150x driver
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* @gpio_base: The index number of the first GPIO assigned to this
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* GPIO expander. The expander will create a block of
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* consecutively numbered gpios beginning at the given base,
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* with the size of the block depending on the model of the
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* expander chip.
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* @oscio_is_gpo: If set to true, the driver will configure OSCIO as a GPO
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* instead of as an oscillator, increasing the size of the
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* GP(I)O pool created by this expander by one. The
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* output-only GPO pin will be added at the end of the block.
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* @io_pullup_ena: A bit-mask which enables or disables the pull-up resistor
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* for each IO line in the expander. Setting the bit at
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* position n will enable the pull-up for the IO at
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* the corresponding offset. For chips with fewer than
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* 16 IO pins, high-end bits are ignored.
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* @io_pulldn_ena: A bit-mask which enables-or disables the pull-down
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* resistor for each IO line in the expander. Setting the
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* bit at position n will enable the pull-down for the IO at
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* the corresponding offset. For chips with fewer than
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* 16 IO pins, high-end bits are ignored.
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* @io_open_drain_ena: A bit-mask which enables-or disables open-drain
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* operation for each IO line in the expander. Setting the
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* bit at position n enables open-drain operation for
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* the IO at the corresponding offset. Clearing the bit
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* enables regular push-pull operation for that IO.
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* For chips with fewer than 16 IO pins, high-end bits
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* are ignored.
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* @io_polarity: A bit-mask which enables polarity inversion for each IO line
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* in the expander. Setting the bit at position n inverts
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* the polarity of that IO line, while clearing it results
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* in normal polarity. For chips with fewer than 16 IO pins,
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* high-end bits are ignored.
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* @irq_summary: The 'summary IRQ' line to which the GPIO expander's INT line
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* is connected, via which it reports interrupt events
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* across all GPIO lines. This must be a real,
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* pre-existing IRQ line.
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* Setting this value < 0 disables the irq_chip functionality
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* of the driver.
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* @irq_base: The first 'virtual IRQ' line at which our block of GPIO-based
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* IRQ lines will appear. Similarly to gpio_base, the expander
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* will create a block of irqs beginning at this number.
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* This value is ignored if irq_summary is < 0.
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* @reset_during_probe: If set to true, the driver will trigger a full
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* reset of the chip at the beginning of the probe
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* in order to place it in a known state.
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*/
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struct sx150x_platform_data {
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unsigned gpio_base;
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bool oscio_is_gpo;
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u16 io_pullup_ena;
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u16 io_pulldn_ena;
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u16 io_open_drain_ena;
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u16 io_polarity;
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int irq_summary;
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unsigned irq_base;
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bool reset_during_probe;
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};
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#endif /* __LINUX_I2C_SX150X_H */
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