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authorTony Lindgren <tony@atomide.com>2019-12-22 10:17:02 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-02-01 09:37:07 +0000
commite0fcfcda809cb3b52e59cfb28d72d95bc93436b0 (patch)
treefc4aacbc4ead5ab6a3804ff01fffeeddb7947ecc
parent342c20044296df71c09282c707e504b442478f7d (diff)
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phy: cpcap-usb: Prevent USB line glitches from waking up modem
[ Upstream commit 63078b6ba09e842f09df052c5728857389fddcd2 ] The micro-USB connector on Motorola Mapphone devices can be muxed between the SoC and the mdm6600 modem. But even when used for the SoC, configuring the PHY with ID pin grounded will wake up the modem from idle state. Looks like the issue is probably caused by line glitches. We can prevent the glitches by using a previously unknown mode of the GPIO mux to prevent the USB lines from being connected to the moden while configuring the USB PHY, and enable the USB lines after configuring the PHY. Note that this only prevents waking up mdm6600 as regular USB A-host mode, and does not help when connected to a lapdock. The lapdock specific issue still needs to be debugged separately. Cc: Merlijn Wajer <merlijn@wizzup.org> Cc: Pavel Machek <pavel@ucw.cz> Cc: Sebastian Reichel <sre@kernel.org> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r--drivers/phy/motorola/phy-cpcap-usb.c18
1 files changed, 15 insertions, 3 deletions
diff --git a/drivers/phy/motorola/phy-cpcap-usb.c b/drivers/phy/motorola/phy-cpcap-usb.c
index 4ba3634009af..593c77dbde2e 100644
--- a/drivers/phy/motorola/phy-cpcap-usb.c
+++ b/drivers/phy/motorola/phy-cpcap-usb.c
@@ -115,7 +115,7 @@ struct cpcap_usb_ints_state {
enum cpcap_gpio_mode {
CPCAP_DM_DP,
CPCAP_MDM_RX_TX,
- CPCAP_UNKNOWN,
+ CPCAP_UNKNOWN_DISABLED, /* Seems to disable USB lines */
CPCAP_OTG_DM_DP,
};
@@ -379,7 +379,8 @@ static int cpcap_usb_set_uart_mode(struct cpcap_phy_ddata *ddata)
{
int error;
- error = cpcap_usb_gpio_set_mode(ddata, CPCAP_DM_DP);
+ /* Disable lines to prevent glitches from waking up mdm6600 */
+ error = cpcap_usb_gpio_set_mode(ddata, CPCAP_UNKNOWN_DISABLED);
if (error)
goto out_err;
@@ -406,6 +407,11 @@ static int cpcap_usb_set_uart_mode(struct cpcap_phy_ddata *ddata)
if (error)
goto out_err;
+ /* Enable UART mode */
+ error = cpcap_usb_gpio_set_mode(ddata, CPCAP_DM_DP);
+ if (error)
+ goto out_err;
+
return 0;
out_err:
@@ -418,7 +424,8 @@ static int cpcap_usb_set_usb_mode(struct cpcap_phy_ddata *ddata)
{
int error;
- error = cpcap_usb_gpio_set_mode(ddata, CPCAP_OTG_DM_DP);
+ /* Disable lines to prevent glitches from waking up mdm6600 */
+ error = cpcap_usb_gpio_set_mode(ddata, CPCAP_UNKNOWN_DISABLED);
if (error)
return error;
@@ -458,6 +465,11 @@ static int cpcap_usb_set_usb_mode(struct cpcap_phy_ddata *ddata)
if (error)
goto out_err;
+ /* Enable USB mode */
+ error = cpcap_usb_gpio_set_mode(ddata, CPCAP_OTG_DM_DP);
+ if (error)
+ goto out_err;
+
return 0;
out_err: