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Diffstat (limited to 'drivers/i2c/muxes/i2c-mux-pca954x.c')
-rw-r--r--drivers/i2c/muxes/i2c-mux-pca954x.c89
1 files changed, 80 insertions, 9 deletions
diff --git a/drivers/i2c/muxes/i2c-mux-pca954x.c b/drivers/i2c/muxes/i2c-mux-pca954x.c
index 2219062104..c3f4ff08ac 100644
--- a/drivers/i2c/muxes/i2c-mux-pca954x.c
+++ b/drivers/i2c/muxes/i2c-mux-pca954x.c
@@ -49,6 +49,7 @@
#include <linux/pm.h>
#include <linux/property.h>
#include <linux/regulator/consumer.h>
+#include <linux/reset.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <dt-bindings/mux/mux.h>
@@ -57,6 +58,20 @@
#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,
@@ -102,6 +117,9 @@ struct pca954x {
unsigned int irq_mask;
raw_spinlock_t lock;
struct regulator *supply;
+
+ struct gpio_desc *reset_gpio;
+ struct reset_control *reset_cont;
};
/* Provide specs for the MAX735x, PCA954x and PCA984x types we know about */
@@ -470,13 +488,69 @@ 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;
return ret;
}
+static int pca954x_get_reset(struct device *dev, struct pca954x *data)
+{
+ data->reset_cont = devm_reset_control_get_optional_shared(dev, NULL);
+ if (IS_ERR(data->reset_cont))
+ return dev_err_probe(dev, PTR_ERR(data->reset_cont),
+ "Failed to get reset\n");
+ else if (data->reset_cont)
+ return 0;
+
+ /*
+ * fallback to legacy reset-gpios
+ */
+ data->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
+ if (IS_ERR(data->reset_gpio)) {
+ return dev_err_probe(dev, PTR_ERR(data->reset_gpio),
+ "Failed to get reset gpio");
+ }
+
+ return 0;
+}
+
+static void pca954x_reset_deassert(struct pca954x *data)
+{
+ if (data->reset_cont)
+ reset_control_deassert(data->reset_cont);
+ else
+ gpiod_set_value_cansleep(data->reset_gpio, 0);
+}
+
/*
* I2C init/probing/exit functions
*/
@@ -485,7 +559,6 @@ static int pca954x_probe(struct i2c_client *client)
const struct i2c_device_id *id = i2c_client_get_device_id(client);
struct i2c_adapter *adap = client->adapter;
struct device *dev = &client->dev;
- struct gpio_desc *gpio;
struct i2c_mux_core *muxc;
struct pca954x *data;
int num;
@@ -513,15 +586,13 @@ static int pca954x_probe(struct i2c_client *client)
return dev_err_probe(dev, ret,
"Failed to enable vdd supply\n");
- /* Reset the mux if a reset GPIO is specified. */
- gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
- if (IS_ERR(gpio)) {
- ret = PTR_ERR(gpio);
+ ret = pca954x_get_reset(dev, data);
+ if (ret)
goto fail_cleanup;
- }
- if (gpio) {
+
+ if (data->reset_cont || data->reset_gpio) {
udelay(1);
- gpiod_set_value_cansleep(gpio, 0);
+ pca954x_reset_deassert(data);
/* Give the chip some time to recover. */
udelay(1);
}