2010-08-11 05:02:27 +04:00
|
|
|
/*
|
|
|
|
* Driver for the Semtech SX150x I2C GPIO Expanders
|
|
|
|
*
|
|
|
|
* Copyright (c) 2010, Code Aurora Forum. All rights reserved.
|
|
|
|
*
|
|
|
|
* This program is free software; you can redistribute it and/or modify
|
|
|
|
* it under the terms of the GNU General Public License version 2 and
|
|
|
|
* only version 2 as published by the Free Software Foundation.
|
|
|
|
*
|
|
|
|
* This program is distributed in the hope that it will be useful,
|
|
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
|
|
* GNU General Public License for more details.
|
|
|
|
*
|
|
|
|
* You should have received a copy of the GNU General Public License
|
|
|
|
* along with this program; if not, write to the Free Software
|
|
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
|
|
|
|
* 02110-1301, USA.
|
|
|
|
*/
|
|
|
|
#ifndef __LINUX_I2C_SX150X_H
|
|
|
|
#define __LINUX_I2C_SX150X_H
|
|
|
|
|
|
|
|
/**
|
|
|
|
* struct sx150x_platform_data - config data for SX150x driver
|
|
|
|
* @gpio_base: The index number of the first GPIO assigned to this
|
|
|
|
* GPIO expander. The expander will create a block of
|
|
|
|
* consecutively numbered gpios beginning at the given base,
|
|
|
|
* with the size of the block depending on the model of the
|
|
|
|
* expander chip.
|
|
|
|
* @oscio_is_gpo: If set to true, the driver will configure OSCIO as a GPO
|
|
|
|
* instead of as an oscillator, increasing the size of the
|
|
|
|
* GP(I)O pool created by this expander by one. The
|
|
|
|
* output-only GPO pin will be added at the end of the block.
|
|
|
|
* @io_pullup_ena: A bit-mask which enables or disables the pull-up resistor
|
|
|
|
* for each IO line in the expander. Setting the bit at
|
|
|
|
* position n will enable the pull-up for the IO at
|
|
|
|
* the corresponding offset. For chips with fewer than
|
|
|
|
* 16 IO pins, high-end bits are ignored.
|
|
|
|
* @io_pulldn_ena: A bit-mask which enables-or disables the pull-down
|
|
|
|
* resistor for each IO line in the expander. Setting the
|
|
|
|
* bit at position n will enable the pull-down for the IO at
|
|
|
|
* the corresponding offset. For chips with fewer than
|
|
|
|
* 16 IO pins, high-end bits are ignored.
|
|
|
|
* @io_open_drain_ena: A bit-mask which enables-or disables open-drain
|
|
|
|
* operation for each IO line in the expander. Setting the
|
|
|
|
* bit at position n enables open-drain operation for
|
|
|
|
* the IO at the corresponding offset. Clearing the bit
|
|
|
|
* enables regular push-pull operation for that IO.
|
|
|
|
* For chips with fewer than 16 IO pins, high-end bits
|
|
|
|
* are ignored.
|
|
|
|
* @io_polarity: A bit-mask which enables polarity inversion for each IO line
|
|
|
|
* in the expander. Setting the bit at position n inverts
|
|
|
|
* the polarity of that IO line, while clearing it results
|
|
|
|
* in normal polarity. For chips with fewer than 16 IO pins,
|
|
|
|
* high-end bits are ignored.
|
|
|
|
* @irq_summary: The 'summary IRQ' line to which the GPIO expander's INT line
|
|
|
|
* is connected, via which it reports interrupt events
|
|
|
|
* across all GPIO lines. This must be a real,
|
|
|
|
* pre-existing IRQ line.
|
|
|
|
* Setting this value < 0 disables the irq_chip functionality
|
|
|
|
* of the driver.
|
|
|
|
* @irq_base: The first 'virtual IRQ' line at which our block of GPIO-based
|
|
|
|
* IRQ lines will appear. Similarly to gpio_base, the expander
|
|
|
|
* will create a block of irqs beginning at this number.
|
|
|
|
* This value is ignored if irq_summary is < 0.
|
gpio: sx150x: correct and refine reset-on-probe behavior
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>
2010-09-10 03:38:02 +04:00
|
|
|
* @reset_during_probe: If set to true, the driver will trigger a full
|
|
|
|
* reset of the chip at the beginning of the probe
|
|
|
|
* in order to place it in a known state.
|
2010-08-11 05:02:27 +04:00
|
|
|
*/
|
|
|
|
struct sx150x_platform_data {
|
|
|
|
unsigned gpio_base;
|
|
|
|
bool oscio_is_gpo;
|
|
|
|
u16 io_pullup_ena;
|
|
|
|
u16 io_pulldn_ena;
|
|
|
|
u16 io_open_drain_ena;
|
|
|
|
u16 io_polarity;
|
|
|
|
int irq_summary;
|
|
|
|
unsigned irq_base;
|
gpio: sx150x: correct and refine reset-on-probe behavior
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>
2010-09-10 03:38:02 +04:00
|
|
|
bool reset_during_probe;
|
2010-08-11 05:02:27 +04:00
|
|
|
};
|
|
|
|
|
|
|
|
#endif /* __LINUX_I2C_SX150X_H */
|