2010-08-10 18:02:27 -07:00
										 
									 
								 
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								/*
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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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												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>
											
										 
										
											2010-09-09 16:38:02 -07:00
										 
									 
								 
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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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											2010-08-10 18:02:27 -07:00
										 
									 
								 
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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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												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>
											
										 
										
											2010-09-09 16:38:02 -07:00
										 
									 
								 
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									bool     reset_during_probe;
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											2010-08-10 18:02:27 -07:00
										 
									 
								 
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								};
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								#endif /* __LINUX_I2C_SX150X_H */
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