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| author | Peter Rosin <peda@axentia.se> | 2016-07-09 21:53:42 +0200 |
|---|---|---|
| committer | Peter Rosin <peda@axentia.se> | 2016-08-25 22:11:02 +0200 |
| commit | b2d57b56047b99f2992fc958d7ac5ead283e9088 (patch) | |
| tree | b5df552ab814d3c1fb852a941b361b767cf14015 | |
| parent | 8f7720b950cf42d316fe5b625867e163a260a83c (diff) | |
| download | linux-stable-b2d57b56047b99f2992fc958d7ac5ead283e9088.tar.gz linux-stable-b2d57b56047b99f2992fc958d7ac5ead283e9088.tar.bz2 linux-stable-b2d57b56047b99f2992fc958d7ac5ead283e9088.zip | |
i2c: mux: add support for 'i2c-mux', 'i2c-arb' and 'i2c-gate' DT subnodes
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>
| -rw-r--r-- | drivers/i2c/i2c-mux.c | 44 | ||||
| -rw-r--r-- | include/linux/i2c-mux.h | 8 |
2 files changed, 42 insertions, 10 deletions
diff --git a/drivers/i2c/i2c-mux.c b/drivers/i2c/i2c-mux.c index 8eee98634cda..c1ae719d1a7a 100644 --- a/drivers/i2c/i2c-mux.c +++ b/drivers/i2c/i2c-mux.c @@ -255,6 +255,10 @@ struct i2c_mux_core *i2c_mux_alloc(struct i2c_adapter *parent, muxc->dev = dev; if (flags & I2C_MUX_LOCKED) muxc->mux_locked = true; + if (flags & I2C_MUX_ARBITRATOR) + muxc->arbitrator = true; + if (flags & I2C_MUX_GATE) + muxc->gate = true; muxc->select = select; muxc->deselect = deselect; muxc->max_adapters = max_adapters; @@ -335,18 +339,42 @@ int i2c_mux_add_adapter(struct i2c_mux_core *muxc, * nothing if !CONFIG_OF. */ if (muxc->dev->of_node) { - struct device_node *child; + struct device_node *dev_node = muxc->dev->of_node; + struct device_node *mux_node, *child = NULL; u32 reg; - for_each_child_of_node(muxc->dev->of_node, child) { - ret = of_property_read_u32(child, "reg", ®); - if (ret) - continue; - if (chan_id == reg) { - priv->adap.dev.of_node = child; - break; + if (muxc->arbitrator) + mux_node = of_get_child_by_name(dev_node, "i2c-arb"); + else if (muxc->gate) + mux_node = of_get_child_by_name(dev_node, "i2c-gate"); + else + mux_node = of_get_child_by_name(dev_node, "i2c-mux"); + + if (mux_node) { + /* A "reg" property indicates an old-style DT entry */ + if (!of_property_read_u32(mux_node, "reg", ®)) { + of_node_put(mux_node); + mux_node = NULL; + } + } + + if (!mux_node) + mux_node = of_node_get(dev_node); + else if (muxc->arbitrator || muxc->gate) + child = of_node_get(mux_node); + + if (!child) { + for_each_child_of_node(mux_node, child) { + ret = of_property_read_u32(child, "reg", ®); + if (ret) + continue; + if (chan_id == reg) + break; } } + + priv->adap.dev.of_node = child; + of_node_put(mux_node); } /* diff --git a/include/linux/i2c-mux.h b/include/linux/i2c-mux.h index d4c1d12f900d..bd74d5706f3b 100644 --- a/include/linux/i2c-mux.h +++ b/include/linux/i2c-mux.h @@ -32,7 +32,9 @@ struct i2c_mux_core { struct i2c_adapter *parent; struct device *dev; - bool mux_locked; + unsigned int mux_locked:1; + unsigned int arbitrator:1; + unsigned int gate:1; void *priv; @@ -51,7 +53,9 @@ struct i2c_mux_core *i2c_mux_alloc(struct i2c_adapter *parent, int (*deselect)(struct i2c_mux_core *, u32)); /* flags for i2c_mux_alloc */ -#define I2C_MUX_LOCKED BIT(0) +#define I2C_MUX_LOCKED BIT(0) +#define I2C_MUX_ARBITRATOR BIT(1) +#define I2C_MUX_GATE BIT(2) static inline void *i2c_mux_priv(struct i2c_mux_core *muxc) { |