| Message ID | 20231005134541.947727-1-naresh.solanki@9elements.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v4,1/2] dt-bindings: i2c: pca954x: Add custom properties for MAX7357 | expand |
Hi Patrick, On Thu, Oct 05, 2023 at 03:45:40PM +0200, Naresh Solanki wrote: > From: Patrick Rudolph <patrick.rudolph@9elements.com> > > Enable additional features based on DT settings and unconditionally > release the shared interrupt pin after 1.6 seconds and allow to use > it as reset. > > These features aren't enabled by default & its up to board designer /&/and/ /its/it's/ > to enable the same as it may have unexpected side effects. which side effects? > These should be validated for proper functioning & detection of devices /&/and/ it ain't WhatsApp :-) > in secondary bus as sometimes it can cause secondary bus being disabled. Is this latest sentence a related to this patch or is it a free information? > Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com> > Signed-off-by: Naresh Solanki <naresh.solanki@9elements.com> [...] > else > data->last_chan = 0; /* Disconnect multiplexer */ > > - ret = i2c_smbus_write_byte(client, data->last_chan); > + if (device_is_compatible(&client->dev, "maxim,max7357")) { > + if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) { > + u8 conf = MAX7357_POR_DEFAULT_CONF; > + /* > + * The interrupt signal is shared with the reset pin. Release the > + * interrupt after 1.6 seconds to allow using the pin as reset. > + * The interrupt isn't serviced yet. > + */ > + conf |= MAX7357_CONF_RELEASE_INT; This setting comes as default, what about the dedicated reset gpio pin? How is the driver going to understand whether from the irq pin is coming a reset or an interrupt? > + if (device_property_read_bool(&client->dev, "maxim,isolate-stuck-channel")) > + conf |= MAX7357_CONF_DISCON_SINGLE_CHAN; > + if (device_property_read_bool(&client->dev, > + "maxim,send-flush-out-sequence")) > + conf |= MAX7357_CONF_FLUSH_OUT; > + if (device_property_read_bool(&client->dev, > + "maxim,preconnection-wiggle-test-enable")) > + conf |= MAX7357_CONF_PRECONNECT_TEST; How are these properties affecting the economy of the driver? Can we have a brief description? Andi
Hi! 2023-10-05 at 15:45, Naresh Solanki wrote: > From: Patrick Rudolph <patrick.rudolph@9elements.com> > > Enable additional features based on DT settings and unconditionally > release the shared interrupt pin after 1.6 seconds and allow to use > it as reset. > > These features aren't enabled by default & its up to board designer > to enable the same as it may have unexpected side effects. > > These should be validated for proper functioning & detection of devices > in secondary bus as sometimes it can cause secondary bus being disabled. > > Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com> > Signed-off-by: Naresh Solanki <naresh.solanki@9elements.com> > --- > Changes in V4: > - Drop max7358 > - Update #define > - Move conf variable > - Print warning when I2C_FUNC_SMBUS_WRITE_BYTE_DATA isn't supported > Changes in V3: > - Delete unused #define > - Update pca954x_init > - Update commit message > > Changes in V2: > - Update comments > - Update check for DT properties > --- > drivers/i2c/muxes/i2c-mux-pca954x.c | 44 ++++++++++++++++++++++++++++- > 1 file changed, 43 insertions(+), 1 deletion(-) > > diff --git a/drivers/i2c/muxes/i2c-mux-pca954x.c b/drivers/i2c/muxes/i2c-mux-pca954x.c > index 2219062104fb..f37ce332078c 100644 > --- a/drivers/i2c/muxes/i2c-mux-pca954x.c > +++ b/drivers/i2c/muxes/i2c-mux-pca954x.c > @@ -57,6 +57,20 @@ > > #define PCA954X_IRQ_OFFSET 4 > > +/* > + * MAX7357's configuration register is writeable after POR, but > + * can be locked by setting the basic mode bit. MAX7358 configuration > + * register is locked by default and needs to be unlocked first. > + * The configuration register holds the following settings: > + */ > +#define MAX7357_CONF_INT_ENABLE BIT(0) > +#define MAX7357_CONF_FLUSH_OUT BIT(1) > +#define MAX7357_CONF_RELEASE_INT BIT(2) > +#define MAX7357_CONF_DISCON_SINGLE_CHAN BIT(4) > +#define MAX7357_CONF_PRECONNECT_TEST BIT(7) > + > +#define MAX7357_POR_DEFAULT_CONF MAX7357_CONF_INT_ENABLE > + > enum pca_type { > max_7356, > max_7357, > @@ -470,7 +484,35 @@ static int pca954x_init(struct i2c_client *client, struct pca954x *data) > else > data->last_chan = 0; /* Disconnect multiplexer */ > > - ret = i2c_smbus_write_byte(client, data->last_chan); > + if (device_is_compatible(&client->dev, "maxim,max7357")) { > + if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) { > + u8 conf = MAX7357_POR_DEFAULT_CONF; > + /* > + * The interrupt signal is shared with the reset pin. Release the > + * interrupt after 1.6 seconds to allow using the pin as reset. > + * The interrupt isn't serviced yet. I'd suggest dropping the word "yet". The interrupt isn't serviced for max7357, period. The "yet" in combination with that 1.6 second window is a bit cunfusing and readers might think that the interrupt is serviced at some later stage or something, when I think the intention of "The interrupt isn't serviced yet" comes with the silent implication that it is simply not implemented yet. > + */ > + conf |= MAX7357_CONF_RELEASE_INT; > + > + if (device_property_read_bool(&client->dev, "maxim,isolate-stuck-channel")) > + conf |= MAX7357_CONF_DISCON_SINGLE_CHAN; > + if (device_property_read_bool(&client->dev, > + "maxim,send-flush-out-sequence")) > + conf |= MAX7357_CONF_FLUSH_OUT; > + if (device_property_read_bool(&client->dev, > + "maxim,preconnection-wiggle-test-enable")) > + conf |= MAX7357_CONF_PRECONNECT_TEST; > + > + ret = i2c_smbus_write_byte_data(client, data->last_chan, conf); > + } else { > + dev_warn(&client->dev, > + "Write byte not supported. Cannot enable enhanced mode features"); Missing \n at the end of the string. Cheers, Peter > + ret = i2c_smbus_write_byte(client, data->last_chan); > + } > + } else { > + ret = i2c_smbus_write_byte(client, data->last_chan); > + } > + > if (ret < 0) > data->last_chan = 0; >
Hi again! [sorry for replying to self] 2023-10-06 at 09:46, Peter Rosin wrote: > 2023-10-05 at 15:45, Naresh Solanki wrote: >> From: Patrick Rudolph <patrick.rudolph@9elements.com> >> ... >> + dev_warn(&client->dev, >> + "Write byte not supported. Cannot enable enhanced mode features"); > > Missing \n at the end of the string. > Also, I2C_FUNC_SMBUS_WRITE_BYTE is separate from I2C_FUNC_SMBUS_WRITE_BYTE_DATA, which makes that "Write byte" misleading. Cheers, Peter
On Thu, 05 Oct 2023 15:45:39 +0200, Naresh Solanki wrote: > From: Patrick Rudolph <patrick.rudolph@9elements.com> > > Maxim Max7357 has a configuration register to enable additional > features. These features aren't enabled by default & its up to > board designer to enable the same as it may have unexpected side effects. > > These should be validated for proper functioning & detection of devices > in secondary bus as sometimes it can cause secondary bus being disabled. > > Add booleans for: > - maxim,isolate-stuck-channel > - maxim,send-flush-out-sequence > - maxim,preconnection-wiggle-test-enable > > Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com> > Signed-off-by: Naresh Solanki <naresh.solanki@9elements.com> > --- > Changes in V4: > - Drop max7358. > Changes in V3: > - Update commit message > Changes in V2: > - Update properties. > --- > .../bindings/i2c/i2c-mux-pca954x.yaml | 30 +++++++++++++++++++ > 1 file changed, 30 insertions(+) > Reviewed-by: Rob Herring <robh@kernel.org>
Hi Andi, On Fri, 6 Oct 2023 at 04:30, Andi Shyti <andi.shyti@kernel.org> wrote: > > Hi Patrick, > > On Thu, Oct 05, 2023 at 03:45:40PM +0200, Naresh Solanki wrote: > > From: Patrick Rudolph <patrick.rudolph@9elements.com> > > > > Enable additional features based on DT settings and unconditionally > > release the shared interrupt pin after 1.6 seconds and allow to use > > it as reset. > > > > These features aren't enabled by default & its up to board designer > > /&/and/ > /its/it's/ Ack > > > to enable the same as it may have unexpected side effects. > > which side effects? > > > These should be validated for proper functioning & detection of devices > > /&/and/ > > it ain't WhatsApp :-) Ack > > > in secondary bus as sometimes it can cause secondary bus being disabled. > > Is this latest sentence a related to this patch or is it a free > information? Its related to the potential side effect of the feature if enabled. > > > Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com> > > Signed-off-by: Naresh Solanki <naresh.solanki@9elements.com> > > [...] > > > else > > data->last_chan = 0; /* Disconnect multiplexer */ > > > > - ret = i2c_smbus_write_byte(client, data->last_chan); > > + if (device_is_compatible(&client->dev, "maxim,max7357")) { > > + if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) { > > + u8 conf = MAX7357_POR_DEFAULT_CONF; > > + /* > > + * The interrupt signal is shared with the reset pin. Release the > > + * interrupt after 1.6 seconds to allow using the pin as reset. > > + * The interrupt isn't serviced yet. > > + */ > > + conf |= MAX7357_CONF_RELEASE_INT; > > This setting comes as default, what about the dedicated reset > gpio pin? How is the driver going to understand whether from the > irq pin is coming a reset or an interrupt? As per datasheet, RELEASE_INT bit in conf is cleared at poweron. The RST/INT is dual function pin. > > > + if (device_property_read_bool(&client->dev, "maxim,isolate-stuck-channel")) > > + conf |= MAX7357_CONF_DISCON_SINGLE_CHAN; > > + if (device_property_read_bool(&client->dev, > > + "maxim,send-flush-out-sequence")) > > + conf |= MAX7357_CONF_FLUSH_OUT; > > + if (device_property_read_bool(&client->dev, > > + "maxim,preconnection-wiggle-test-enable")) > > + conf |= MAX7357_CONF_PRECONNECT_TEST; > > How are these properties affecting the economy of the driver? Can > we have a brief description? Not sure what you mean. Are you asking for impact on the driver or feature description ? Note: These are chip features & this patch is intended to enable them based on DT settings. Regards, Naresh > > Andi
Hi On Fri, 6 Oct 2023 at 13:16, Peter Rosin <peda@axentia.se> wrote: > > Hi! > > 2023-10-05 at 15:45, Naresh Solanki wrote: > > From: Patrick Rudolph <patrick.rudolph@9elements.com> > > > > Enable additional features based on DT settings and unconditionally > > release the shared interrupt pin after 1.6 seconds and allow to use > > it as reset. > > > > These features aren't enabled by default & its up to board designer > > to enable the same as it may have unexpected side effects. > > > > These should be validated for proper functioning & detection of devices > > in secondary bus as sometimes it can cause secondary bus being disabled. > > > > Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com> > > Signed-off-by: Naresh Solanki <naresh.solanki@9elements.com> > > --- > > Changes in V4: > > - Drop max7358 > > - Update #define > > - Move conf variable > > - Print warning when I2C_FUNC_SMBUS_WRITE_BYTE_DATA isn't supported > > Changes in V3: > > - Delete unused #define > > - Update pca954x_init > > - Update commit message > > > > Changes in V2: > > - Update comments > > - Update check for DT properties > > --- > > drivers/i2c/muxes/i2c-mux-pca954x.c | 44 ++++++++++++++++++++++++++++- > > 1 file changed, 43 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/i2c/muxes/i2c-mux-pca954x.c b/drivers/i2c/muxes/i2c-mux-pca954x.c > > index 2219062104fb..f37ce332078c 100644 > > --- a/drivers/i2c/muxes/i2c-mux-pca954x.c > > +++ b/drivers/i2c/muxes/i2c-mux-pca954x.c > > @@ -57,6 +57,20 @@ > > > > #define PCA954X_IRQ_OFFSET 4 > > > > +/* > > + * MAX7357's configuration register is writeable after POR, but > > + * can be locked by setting the basic mode bit. MAX7358 configuration > > + * register is locked by default and needs to be unlocked first. > > + * The configuration register holds the following settings: > > + */ > > +#define MAX7357_CONF_INT_ENABLE BIT(0) > > +#define MAX7357_CONF_FLUSH_OUT BIT(1) > > +#define MAX7357_CONF_RELEASE_INT BIT(2) > > +#define MAX7357_CONF_DISCON_SINGLE_CHAN BIT(4) > > +#define MAX7357_CONF_PRECONNECT_TEST BIT(7) > > + > > +#define MAX7357_POR_DEFAULT_CONF MAX7357_CONF_INT_ENABLE > > + > > enum pca_type { > > max_7356, > > max_7357, > > @@ -470,7 +484,35 @@ static int pca954x_init(struct i2c_client *client, struct pca954x *data) > > else > > data->last_chan = 0; /* Disconnect multiplexer */ > > > > - ret = i2c_smbus_write_byte(client, data->last_chan); > > + if (device_is_compatible(&client->dev, "maxim,max7357")) { > > + if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) { > > + u8 conf = MAX7357_POR_DEFAULT_CONF; > > + /* > > + * The interrupt signal is shared with the reset pin. Release the > > + * interrupt after 1.6 seconds to allow using the pin as reset. > > + * The interrupt isn't serviced yet. > > I'd suggest dropping the word "yet". The interrupt isn't serviced for > max7357, period. The "yet" in combination with that 1.6 second window is > a bit cunfusing and readers might think that the interrupt is serviced > at some later stage or something, when I think the intention of "The > interrupt isn't serviced yet" comes with the silent implication that it > is simply not implemented yet. Sure. > > > + */ > > + conf |= MAX7357_CONF_RELEASE_INT; > > + > > + if (device_property_read_bool(&client->dev, "maxim,isolate-stuck-channel")) > > + conf |= MAX7357_CONF_DISCON_SINGLE_CHAN; > > + if (device_property_read_bool(&client->dev, > > + "maxim,send-flush-out-sequence")) > > + conf |= MAX7357_CONF_FLUSH_OUT; > > + if (device_property_read_bool(&client->dev, > > + "maxim,preconnection-wiggle-test-enable")) > > + conf |= MAX7357_CONF_PRECONNECT_TEST; > > + > > + ret = i2c_smbus_write_byte_data(client, data->last_chan, conf); > > + } else { > > + dev_warn(&client->dev, > > + "Write byte not supported. Cannot enable enhanced mode features"); > > Missing \n at the end of the string. Sure. Will also update it as 'Write byte data not supported. Cannot enable enhanced mode features\n' Regards, Naresh > > Cheers, > Peter > > > + ret = i2c_smbus_write_byte(client, data->last_chan); > > + } > > + } else { > > + ret = i2c_smbus_write_byte(client, data->last_chan); > > + } > > + > > if (ret < 0) > > data->last_chan = 0; > >
diff --git a/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.yaml b/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.yaml index 2d7bb998b0e9..9aa0585200c9 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.yaml +++ b/Documentation/devicetree/bindings/i2c/i2c-mux-pca954x.yaml @@ -71,6 +71,23 @@ properties: description: A voltage regulator supplying power to the chip. On PCA9846 the regulator supplies power to VDD2 (core logic) and optionally to VDD1. + maxim,isolate-stuck-channel: + type: boolean + description: Allows to use non faulty channels while a stuck channel is + isolated from the upstream bus. If not set all channels are isolated from + the upstream bus until the fault is cleared. + + maxim,send-flush-out-sequence: + type: boolean + description: Send a flush-out sequence to stuck auxiliary buses + automatically after a stuck channel is being detected. + + maxim,preconnection-wiggle-test-enable: + type: boolean + description: Send a STOP condition to the auxiliary buses when the switch + register activates a channel to detect a stuck high fault. On fault the + channel is isolated from the upstream bus. + required: - compatible - reg @@ -95,6 +112,19 @@ allOf: "#interrupt-cells": false interrupt-controller: false + - if: + not: + properties: + compatible: + contains: + enum: + - maxim,max7357 + then: + properties: + maxim,isolate-stuck-channel: false + maxim,send-flush-out-sequence: false + maxim,preconnection-wiggle-test-enable: false + unevaluatedProperties: false examples: