Hello all,
When a uart of the CP2105 USB-serial chip is programmed to be in modem
mode, all its gpio pins are in alternate use and none are available for
gpio. Still the cp210x driver tries to add a gpiochip unconditionally,
which results in an error.
cp210x 1-1.4.4:1.0: cp210x converter detected
usb 1-1.4.4: cp210x converter now attached to ttyUSB0
cp210x 1-1.4.4:1.1: cp210x converter detected
gpio gpiochip2: (cp210x): tried to insert a GPIO chip with zero lines
gpiochip_add_data_with_key: GPIOs 0..-1 (cp210x) failed to register,
-22
cp210x 1-1.4.4:1.1: GPIO initialisation failed: -22
usb 1-1.4.4: cp210x converter now attached to ttyUSB1
I propose to add something like the following to cp210x_gpio_init
+ unsigned long valid_mask, altfunc_mask;
...
+ altfunc_mask = priv->gpio_altfunc;
+ bitmap_complement(&valid_mask, &altfunc_mask, priv->gc.ngpio);
+ if (bitmap_empty(&valid_mask, priv->gc.ngpio))
+ return 0;
+
priv->gc.label = "cp210x";
priv->gc.request = cp210x_gpio_request;
priv->gc.get_direction = cp210x_gpio_direction_get;
I can write a proper patch, but am unsure if and what the Fixes tag
should be.
Maarten
