Commit df7cbce4 authored by Patrick Rudolph's avatar Patrick Rudolph Committed by Andi Shyti
Browse files

i2c: muxes: pca954x: Enable features on MAX7357 



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 and it's up to board designer
to validate for proper functioning and detection of devices in secondary
bus as sometimes it can cause secondary bus being disabled.

Signed-off-by: default avatarPatrick Rudolph <patrick.rudolph@9elements.com>
Signed-off-by: default avatarNaresh Solanki <naresh.solanki@9elements.com>
Reviewed-by: default avatarAndi Shyti <andi.shyti@kernel.org>
Signed-off-by: default avatarAndi Shyti <andi.shyti@kernel.org>
parent 5731cb4b

drivers/i2c/muxes/i2c-mux-pca954x.c

+42 −1
Original line number Diff line number Diff line
@@ -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 +484,34 @@ static int pca954x_init(struct i2c_client *client, struct pca954x *data) 
	else

		data->last_chan = 0; /* Disconnect multiplexer */



	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.

			 */

			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 data not supported."

				 "Cannot enable enhanced mode features\n");

			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;