Hi!
2023-10-05 at 15:45, Naresh Solanki wrote:
> From: Patrick Rudolph <patrick.rudolph@xxxxxxxxxxxxx>
>
> 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@xxxxxxxxxxxxx>
> Signed-off-by: Naresh Solanki <naresh.solanki@xxxxxxxxxxxxx>
> ---
> 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;
>
