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Subject[PATCH] USB: serial: cp210x: support all gpios on CP2102N QFN28 package
Date
The QFN28 package version of the CP2102N has three additional gpio pins.
Add support for these.

Signed-off-by: Mans Rullgard <mans@mansr.com>
---
drivers/usb/serial/cp210x.c | 19 +++++++++++++------
1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c
index c0777a374a88..336a3c0f9f2c 100644
--- a/drivers/usb/serial/cp210x.c
+++ b/drivers/usb/serial/cp210x.c
@@ -1574,12 +1574,6 @@ static int cp2102n_gpioconf_init(struct usb_serial *serial)
if (config_version != 0x01)
return -ENOTSUPP;

- /*
- * We only support 4 GPIOs even on the QFN28 package, because
- * config locations of GPIOs 4-6 determined using reverse
- * engineering revealed conflicting offsets with other
- * documented functions. So we'll just play it safe for now.
- */
priv->gc.ngpio = 4;

/*
@@ -1594,6 +1588,19 @@ static int cp2102n_gpioconf_init(struct usb_serial *serial)
/* 0 indicates GPIO mode, 1 is alternate function */
priv->gpio_altfunc = (gpio_ctrl >> 2) & 0x0f;

+ if (priv->partnum == CP210X_PARTNUM_CP2102N_QFN28) {
+ /*
+ * For the QFN28 package, GPIO4-6 are controlled by
+ * the low three bits of the mode/latch fields.
+ * Contrary to the document linked above, the bits for
+ * the SUSPEND pins are elsewhere. No alternate
+ * function is available for these pins.
+ */
+ priv->gc.ngpio = 7;
+ gpio_latch |= (gpio_rst_latch & 7) << 4;
+ priv->gpio_pushpull |= (gpio_pushpull & 7) << 4;
+ }
+
/*
* The CP2102N does not strictly has input and output pin modes,
* it only knows open-drain and push-pull modes which is set at
--
2.20.1
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