diff options
Diffstat (limited to 'drivers/i2c/muxes/i2c-mux-pca954x.c')
| -rw-r--r-- | drivers/i2c/muxes/i2c-mux-pca954x.c | 89 |
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); } |