Commit 6f7ec77c authored by Stefan Agner's avatar Stefan Agner Committed by Johan Hovold
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USB: serial: cp210x: fix alternate function for CP2102N QFN20 



The QFN20 part has a different GPIO/port function assignment. The
configuration struct bit field ordered as TX/RX/RS485/WAKEUP/CLK
which exactly matches GPIO0-3 for QFN24/28. However, QFN20 has a
different GPIO to primary function assignment.

Special case QFN20 to follow to properly detect which GPIOs are
available.

Signed-off-by: default avatarStefan Agner <stefan@agner.ch>
Link: https://lore.kernel.org/r/51830b2b24118eb0f77c5c9ac64ffb2f519dbb1d.1622218300.git.stefan@agner.ch


Fixes: c8acfe0a ("USB: serial: cp210x: implement GPIO support for CP2102N")
Cc: stable@vger.kernel.org	# 4.19
Signed-off-by: default avatarJohan Hovold <johan@kernel.org>
parent bc96c72d

drivers/usb/serial/cp210x.c

+19 −1
Original line number Diff line number Diff line
@@ -537,6 +537,12 @@ struct cp210x_single_port_config { 
#define CP210X_2NCONFIG_GPIO_RSTLATCH_IDX	587

#define CP210X_2NCONFIG_GPIO_CONTROL_IDX	600



/* CP2102N QFN20 port configuration values */

#define CP2102N_QFN20_GPIO2_TXLED_MODE		BIT(2)

#define CP2102N_QFN20_GPIO3_RXLED_MODE		BIT(3)

#define CP2102N_QFN20_GPIO1_RS485_MODE		BIT(4)

#define CP2102N_QFN20_GPIO0_CLK_MODE		BIT(6)



/* CP210X_VENDOR_SPECIFIC, CP210X_WRITE_LATCH call writes these 0x2 bytes. */

struct cp210x_gpio_write {

	u8	mask;
@@ -1733,7 +1739,19 @@ static int cp2102n_gpioconf_init(struct usb_serial *serial) 
	priv->gpio_pushpull = (gpio_pushpull >> 3) & 0x0f;



	/* 0 indicates GPIO mode, 1 is alternate function */

	if (priv->partnum == CP210X_PARTNUM_CP2102N_QFN20) {

		/* QFN20 is special... */

		if (gpio_ctrl & CP2102N_QFN20_GPIO0_CLK_MODE)   /* GPIO 0 */

			priv->gpio_altfunc |= BIT(0);

		if (gpio_ctrl & CP2102N_QFN20_GPIO1_RS485_MODE) /* GPIO 1 */

			priv->gpio_altfunc |= BIT(1);

		if (gpio_ctrl & CP2102N_QFN20_GPIO2_TXLED_MODE) /* GPIO 2 */

			priv->gpio_altfunc |= BIT(2);

		if (gpio_ctrl & CP2102N_QFN20_GPIO3_RXLED_MODE) /* GPIO 3 */

			priv->gpio_altfunc |= BIT(3);

	} else {

		priv->gpio_altfunc = (gpio_ctrl >> 2) & 0x0f;

	}



	if (priv->partnum == CP210X_PARTNUM_CP2102N_QFN28) {

		/*