| Message ID | 20191015044839.23746-2-biwen.li@nxp.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v2,1/2] dt-bindings: i2c: add property idle-state | expand |
On 2019-10-15 06:48, Biwen Li wrote: > This adds property idle-state > > Signed-off-by: Biwen Li <biwen.li@nxp.com> > --- > Change in v2: > - update subject and description > - add property idle-state > > drivers/i2c/muxes/i2c-mux-pca954x.c | 47 ++++++++++++++++++----------- > 1 file changed, 30 insertions(+), 17 deletions(-) > > diff --git a/drivers/i2c/muxes/i2c-mux-pca954x.c b/drivers/i2c/muxes/i2c-mux-pca954x.c > index 923aa3a5a3dc..8ec586342b92 100644 > --- a/drivers/i2c/muxes/i2c-mux-pca954x.c > +++ b/drivers/i2c/muxes/i2c-mux-pca954x.c > @@ -86,7 +86,7 @@ struct pca954x { > > u8 last_chan; /* last register value */ > /* MUX_IDLE_AS_IS, MUX_IDLE_DISCONNECT or >= 0 for channel */ > - s8 idle_state; > + s32 idle_state; > > struct i2c_client *client; > > @@ -256,7 +256,7 @@ static int pca954x_deselect_mux(struct i2c_mux_core *muxc, u32 chan) > { > struct pca954x *data = i2c_mux_priv(muxc); > struct i2c_client *client = data->client; > - s8 idle_state; > + s32 idle_state; > > idle_state = READ_ONCE(data->idle_state); > if (idle_state >= 0) > @@ -402,6 +402,25 @@ static void pca954x_cleanup(struct i2c_mux_core *muxc) > i2c_mux_del_adapters(muxc); > } > > +static int pca954x_init(struct i2c_client *client, struct pca954x *data) > +{ > + /* > + * Write the mux register at addr to verify > + * that the mux is in fact present. This also > + * initializes the mux to disconnected state. > + */ This comment belongs in pca954x_probe, before the call to this function. However, the comment may now be be wrong since the mux is not always initialized to the disconnected state. > + if (data->idle_state >= 0) { > + /* Always enable multiplexer */ While I understand that it is important for your case that the mux is always enabled, this is just a side effect of having a specific idle-state. I suggest that you remove this comment. > + if (data->chip->muxtype == pca954x_ismux) > + data->last_chan = data->idle_state | data->chip->enable; > + else > + data->last_chan = 1 << data->idle_state; The meat of this "if" is still duplicated, I was suggesting a helper that only did the regval calculation so that the new helper could also be used from pca954x_select_chan. > + } else { > + /* Disconnect multiplexer */ > + data->last_chan = 0; /* force the first selection */ These two comments should be combined. > + } > + return i2c_smbus_write_byte(client, data->last_chan); > +} > /* > * I2C init/probing/exit functions > */ > @@ -411,7 +430,6 @@ static int pca954x_probe(struct i2c_client *client, > struct i2c_adapter *adap = client->adapter; > struct device *dev = &client->dev; > struct device_node *np = dev->of_node; > - bool idle_disconnect_dt; > struct gpio_desc *gpio; > struct i2c_mux_core *muxc; > struct pca954x *data; > @@ -462,22 +480,18 @@ static int pca954x_probe(struct i2c_client *client, > } > } > > - /* Write the mux register at addr to verify > - * that the mux is in fact present. This also > - * initializes the mux to disconnected state. > - */ > - if (i2c_smbus_write_byte(client, 0) < 0) { > + if (of_property_read_u32(np, "idle-state", &data->idle_state)) > + data->idle_state = MUX_IDLE_AS_IS; > + > + if (of_property_read_bool(np, "i2c-mux-idle-disconnect")) > + data->idle_state = MUX_IDLE_DISCONNECT; I think you should ignore i2c-mux-idle-disconnect if idle-state is present. I.e. move this "if" statement into the body of the former "if". Also, you have broken things if np is NULL. Cheers, Peter > + > + ret = pca954x_init(client, data); > + if (ret < 0) { > dev_warn(dev, "probe failed\n"); > return -ENODEV; > } > > - data->last_chan = 0; /* force the first selection */ > - data->idle_state = MUX_IDLE_AS_IS; > - > - idle_disconnect_dt = np && > - of_property_read_bool(np, "i2c-mux-idle-disconnect"); > - if (idle_disconnect_dt) > - data->idle_state = MUX_IDLE_DISCONNECT; > > ret = pca954x_irq_setup(muxc); > if (ret) > @@ -531,8 +545,7 @@ static int pca954x_resume(struct device *dev) > struct i2c_mux_core *muxc = i2c_get_clientdata(client); > struct pca954x *data = i2c_mux_priv(muxc); > > - data->last_chan = 0; > - return i2c_smbus_write_byte(client, 0); > + return pca954x_init(client, data); > } > #endif > >
> > On 2019-10-15 06:48, Biwen Li wrote: > > This adds property idle-state > > > > Signed-off-by: Biwen Li <biwen.li@nxp.com> > > --- > > Change in v2: > > - update subject and description > > - add property idle-state > > > > drivers/i2c/muxes/i2c-mux-pca954x.c | 47 > > ++++++++++++++++++----------- > > 1 file changed, 30 insertions(+), 17 deletions(-) > > > > diff --git a/drivers/i2c/muxes/i2c-mux-pca954x.c > > b/drivers/i2c/muxes/i2c-mux-pca954x.c > > index 923aa3a5a3dc..8ec586342b92 100644 > > --- a/drivers/i2c/muxes/i2c-mux-pca954x.c > > +++ b/drivers/i2c/muxes/i2c-mux-pca954x.c > > @@ -86,7 +86,7 @@ struct pca954x { > > > > u8 last_chan; /* last register value */ > > /* MUX_IDLE_AS_IS, MUX_IDLE_DISCONNECT or >= 0 for channel */ > > - s8 idle_state; > > + s32 idle_state; > > > > struct i2c_client *client; > > > > @@ -256,7 +256,7 @@ static int pca954x_deselect_mux(struct > > i2c_mux_core *muxc, u32 chan) { > > struct pca954x *data = i2c_mux_priv(muxc); > > struct i2c_client *client = data->client; > > - s8 idle_state; > > + s32 idle_state; > > > > idle_state = READ_ONCE(data->idle_state); > > if (idle_state >= 0) > > @@ -402,6 +402,25 @@ static void pca954x_cleanup(struct > i2c_mux_core *muxc) > > i2c_mux_del_adapters(muxc); > > } > > > > +static int pca954x_init(struct i2c_client *client, struct pca954x > > +*data) { > > + /* > > + * Write the mux register at addr to verify > > + * that the mux is in fact present. This also > > + * initializes the mux to disconnected state. > > + */ > > This comment belongs in pca954x_probe, before the call to this function. > However, the comment may now be be wrong since the mux is not always > initialized to the disconnected state. Got it, I will update it in v3. > > > + if (data->idle_state >= 0) { > > + /* Always enable multiplexer */ > > While I understand that it is important for your case that the mux is always > enabled, this is just a side effect of having a specific idle-state. I suggest that > you remove this comment. Got it, I will remove it in v3. > > > + if (data->chip->muxtype == pca954x_ismux) > > + data->last_chan = data->idle_state | > data->chip->enable; > > + else > > + data->last_chan = 1 << data->idle_state; > > The meat of this "if" is still duplicated, I was suggesting a helper that only did > the regval calculation so that the new helper could also be used from > pca954x_select_chan.o > > > + } else { > > + /* Disconnect multiplexer */ > > + data->last_chan = 0; /* force the first selection */ > > These two comments should be combined. Got it. > > > + } > > + return i2c_smbus_write_byte(client, data->last_chan); } > > /* > > * I2C init/probing/exit functions > > */ > > @@ -411,7 +430,6 @@ static int pca954x_probe(struct i2c_client *client, > > struct i2c_adapter *adap = client->adapter; > > struct device *dev = &client->dev; > > struct device_node *np = dev->of_node; > > - bool idle_disconnect_dt; > > struct gpio_desc *gpio; > > struct i2c_mux_core *muxc; > > struct pca954x *data; > > @@ -462,22 +480,18 @@ static int pca954x_probe(struct i2c_client > *client, > > } > > } > > > > - /* Write the mux register at addr to verify > > - * that the mux is in fact present. This also > > - * initializes the mux to disconnected state. > > - */ > > - if (i2c_smbus_write_byte(client, 0) < 0) { > > + if (of_property_read_u32(np, "idle-state", &data->idle_state)) > > + data->idle_state = MUX_IDLE_AS_IS; > > + > > + if (of_property_read_bool(np, "i2c-mux-idle-disconnect")) > > + data->idle_state = MUX_IDLE_DISCONNECT; > > I think you should ignore i2c-mux-idle-disconnect if idle-state is present. > I.e. move this "if" statement into the body of the former "if". Also, you have > broken things if np is NULL. Got it, I will modify it in v3. > > Cheers, > Peter > > > + > > + ret = pca954x_init(client, data); > > + if (ret < 0) { > > dev_warn(dev, "probe failed\n"); > > return -ENODEV; > > } > > > > - data->last_chan = 0; /* force the first selection */ > > - data->idle_state = MUX_IDLE_AS_IS; > > - > > - idle_disconnect_dt = np && > > - of_property_read_bool(np, "i2c-mux-idle-disconnect"); > > - if (idle_disconnect_dt) > > - data->idle_state = MUX_IDLE_DISCONNECT; > > > > ret = pca954x_irq_setup(muxc); > > if (ret) > > @@ -531,8 +545,7 @@ static int pca954x_resume(struct device *dev) > > struct i2c_mux_core *muxc = i2c_get_clientdata(client); > > struct pca954x *data = i2c_mux_priv(muxc); > > > > - data->last_chan = 0; > > - return i2c_smbus_write_byte(client, 0); > > + return pca954x_init(client, data); > > } > > #endif > > > >
diff --git a/drivers/i2c/muxes/i2c-mux-pca954x.c b/drivers/i2c/muxes/i2c-mux-pca954x.c index 923aa3a5a3dc..8ec586342b92 100644 --- a/drivers/i2c/muxes/i2c-mux-pca954x.c +++ b/drivers/i2c/muxes/i2c-mux-pca954x.c @@ -86,7 +86,7 @@ struct pca954x { u8 last_chan; /* last register value */ /* MUX_IDLE_AS_IS, MUX_IDLE_DISCONNECT or >= 0 for channel */ - s8 idle_state; + s32 idle_state; struct i2c_client *client; @@ -256,7 +256,7 @@ static int pca954x_deselect_mux(struct i2c_mux_core *muxc, u32 chan) { struct pca954x *data = i2c_mux_priv(muxc); struct i2c_client *client = data->client; - s8 idle_state; + s32 idle_state; idle_state = READ_ONCE(data->idle_state); if (idle_state >= 0) @@ -402,6 +402,25 @@ static void pca954x_cleanup(struct i2c_mux_core *muxc) i2c_mux_del_adapters(muxc); } +static int pca954x_init(struct i2c_client *client, struct pca954x *data) +{ + /* + * Write the mux register at addr to verify + * that the mux is in fact present. This also + * initializes the mux to disconnected state. + */ + if (data->idle_state >= 0) { + /* Always enable multiplexer */ + if (data->chip->muxtype == pca954x_ismux) + data->last_chan = data->idle_state | data->chip->enable; + else + data->last_chan = 1 << data->idle_state; + } else { + /* Disconnect multiplexer */ + data->last_chan = 0; /* force the first selection */ + } + return i2c_smbus_write_byte(client, data->last_chan); +} /* * I2C init/probing/exit functions */ @@ -411,7 +430,6 @@ static int pca954x_probe(struct i2c_client *client, struct i2c_adapter *adap = client->adapter; struct device *dev = &client->dev; struct device_node *np = dev->of_node; - bool idle_disconnect_dt; struct gpio_desc *gpio; struct i2c_mux_core *muxc; struct pca954x *data; @@ -462,22 +480,18 @@ static int pca954x_probe(struct i2c_client *client, } } - /* Write the mux register at addr to verify - * that the mux is in fact present. This also - * initializes the mux to disconnected state. - */ - if (i2c_smbus_write_byte(client, 0) < 0) { + if (of_property_read_u32(np, "idle-state", &data->idle_state)) + data->idle_state = MUX_IDLE_AS_IS; + + if (of_property_read_bool(np, "i2c-mux-idle-disconnect")) + data->idle_state = MUX_IDLE_DISCONNECT; + + ret = pca954x_init(client, data); + if (ret < 0) { dev_warn(dev, "probe failed\n"); return -ENODEV; } - data->last_chan = 0; /* force the first selection */ - data->idle_state = MUX_IDLE_AS_IS; - - idle_disconnect_dt = np && - of_property_read_bool(np, "i2c-mux-idle-disconnect"); - if (idle_disconnect_dt) - data->idle_state = MUX_IDLE_DISCONNECT; ret = pca954x_irq_setup(muxc); if (ret) @@ -531,8 +545,7 @@ static int pca954x_resume(struct device *dev) struct i2c_mux_core *muxc = i2c_get_clientdata(client); struct pca954x *data = i2c_mux_priv(muxc); - data->last_chan = 0; - return i2c_smbus_write_byte(client, 0); + return pca954x_init(client, data); } #endif
This adds property idle-state Signed-off-by: Biwen Li <biwen.li@nxp.com> --- Change in v2: - update subject and description - add property idle-state drivers/i2c/muxes/i2c-mux-pca954x.c | 47 ++++++++++++++++++----------- 1 file changed, 30 insertions(+), 17 deletions(-)