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SubjectRe: [PATCH v2 5/8] i2c: mux: add support for 'i2c-mux', 'i2c-arb' and 'i2c-gate' DT subnodes
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Hi Peter,

On 08/15/2016 04:40 PM, Peter Rosin wrote:
> 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').
>
> Signed-off-by: Peter Rosin <peda@axentia.se>
> ---
> drivers/i2c/i2c-mux.c | 44 ++++++++++++++++++++++++++++++++++++--------
> 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", &reg);
> - if (ret)
> - continue;
> - if (chan_id == reg) {
> - priv->adap.dev.of_node = child;
> - break;

missing of_node_put(child);

Also adding an empty line would be perfect.

> + 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", &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", &reg);
> + if (ret)
> + continue;
> + if (chan_id == reg)
> + break;

missing of_node_put(child);

> }
> }
> +
> + 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)
> {
>

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