forked from mirrors/linux
b2d57b5604
Backwards compatibility is preserved; the subnodes are in practice optional. However, the mux core needs to know what subnode it should examine, so add a couple of new flags for i2c_mux_alloc for this purpose. The rule is that if the mux core finds a 'reg' property in the appropriate subnode, e.g. if 'reg' exists in the 'i2c-mux' subnode, then the mux core will assume that this is an old style entry and not an i2c-mux subnode (correspondingly for arbitrators and gates with 'i2c-arb' and 'i2c-gate'). Reviewed-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Peter Rosin <peda@axentia.se>
80 lines
2.3 KiB
C
80 lines
2.3 KiB
C
/*
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*
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* i2c-mux.h - functions for the i2c-bus mux support
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*
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* Copyright (c) 2008-2009 Rodolfo Giometti <giometti@linux.it>
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* Copyright (c) 2008-2009 Eurotech S.p.A. <info@eurotech.it>
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* Michael Lawnick <michael.lawnick.ext@nsn.com>
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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 as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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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,
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* MA 02110-1301 USA.
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*/
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#ifndef _LINUX_I2C_MUX_H
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#define _LINUX_I2C_MUX_H
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#ifdef __KERNEL__
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#include <linux/bitops.h>
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struct i2c_mux_core {
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struct i2c_adapter *parent;
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struct device *dev;
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unsigned int mux_locked:1;
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unsigned int arbitrator:1;
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unsigned int gate:1;
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void *priv;
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int (*select)(struct i2c_mux_core *, u32 chan_id);
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int (*deselect)(struct i2c_mux_core *, u32 chan_id);
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int num_adapters;
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int max_adapters;
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struct i2c_adapter *adapter[0];
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};
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struct i2c_mux_core *i2c_mux_alloc(struct i2c_adapter *parent,
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struct device *dev, int max_adapters,
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int sizeof_priv, u32 flags,
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int (*select)(struct i2c_mux_core *, u32),
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int (*deselect)(struct i2c_mux_core *, u32));
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/* flags for i2c_mux_alloc */
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#define I2C_MUX_LOCKED BIT(0)
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#define I2C_MUX_ARBITRATOR BIT(1)
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#define I2C_MUX_GATE BIT(2)
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static inline void *i2c_mux_priv(struct i2c_mux_core *muxc)
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{
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return muxc->priv;
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}
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struct i2c_adapter *i2c_root_adapter(struct device *dev);
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/*
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* Called to create an i2c bus on a multiplexed bus segment.
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* The chan_id parameter is passed to the select and deselect
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* callback functions to perform hardware-specific mux control.
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*/
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int i2c_mux_add_adapter(struct i2c_mux_core *muxc,
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u32 force_nr, u32 chan_id,
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unsigned int class);
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void i2c_mux_del_adapters(struct i2c_mux_core *muxc);
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#endif /* __KERNEL__ */
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#endif /* _LINUX_I2C_MUX_H */
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