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authorPatrick Rudolph <patrick.rudolph@9elements.com>2024-01-30 17:49:01 +0530
committerAndi Shyti <andi.shyti@kernel.org>2024-02-08 09:34:16 +0100
commitdf7cbce47a993b14dc2cf71ba0cba081766277e0 (patch)
treecc6cef4703d276f156f4ac5cfd1121e139b96593 /drivers/i2c/muxes
parent5731cb4bef55d1fb649bc862b8e6f8e4cfd10e92 (diff)
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: Patrick Rudolph <patrick.rudolph@9elements.com> Signed-off-by: Naresh Solanki <naresh.solanki@9elements.com> Reviewed-by: Andi Shyti <andi.shyti@kernel.org> Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Diffstat (limited to 'drivers/i2c/muxes')
-rw-r--r--drivers/i2c/muxes/i2c-mux-pca954x.c43
1 files changed, 42 insertions, 1 deletions
diff --git a/drivers/i2c/muxes/i2c-mux-pca954x.c b/drivers/i2c/muxes/i2c-mux-pca954x.c
index 2219062104fb..f5dfc33b97c0 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 +484,34 @@ 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.
+ */
+ 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;