From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kishon Vijay Abraham I Subject: [PATCH 3/4] usb: phy: omap-usb3: Decrease the number of transitions to recovery Date: Wed, 19 Sep 2012 17:00:28 +0530 Message-ID: <1348054229-27362-4-git-send-email-kishon@ti.com> References: <1348054229-27362-1-git-send-email-kishon@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1348054229-27362-1-git-send-email-kishon-l0cyMroinI0@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Sender: "devicetree-discuss" To: grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org, rob.herring-bsGFqQB8/DxBDgjK7y7TUQ@public.gmane.org, rob-VoJi6FS/r0vR7s880joybQ@public.gmane.org, linux-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org, kishon-l0cyMroinI0@public.gmane.org, balbi-l0cyMroinI0@public.gmane.org, linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org, linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org Cc: Moiz Sonasath List-Id: devicetree@vger.kernel.org Power-cycling the PHY (partially) decreases the number of transitions to "Recovery" state. Hence changed the power up sequence to a partial power-up before a full power-up of the PHY. Signed-off-by: Kishon Vijay Abraham I Signed-off-by: Moiz Sonasath --- drivers/usb/phy/omap-usb3.c | 43 ++++++++++++++++++++++++++++++++++++------ include/linux/usb/omap_usb.h | 1 + 2 files changed, 38 insertions(+), 6 deletions(-) diff --git a/drivers/usb/phy/omap-usb3.c b/drivers/usb/phy/omap-usb3.c index 26402d5..fb3c5e6 100644 --- a/drivers/usb/phy/omap-usb3.c +++ b/drivers/usb/phy/omap-usb3.c @@ -35,13 +35,15 @@ static struct usb_dpll_params omap_usb3_dpll_params[NUM_SYS_CLKS] = { }; /** - * omap5_usb_phy_power - power on/off the serializer using control module + * omap5_usb_phy_partial_powerup - power on the serializer using control module * @phy: struct omap_usb * - * @on: 0 to off and 1 to on based on powering on or off the PHY * - * omap_usb3 can call this API to power on or off the PHY. + * After the dwc3 module is disabled and enabled again the synchronization + * between dwc3 and phy goes bad and the device does not get enumerated + * in superspeed mode. After some trials it was found powering up TX and + * part of RX PHY helped to solve the issue. */ -static int omap5_usb_phy_power(struct omap_usb *phy, bool on) +static int omap5_usb_phy_partial_powerup(struct omap_usb *phy) { u32 val; unsigned long rate; @@ -58,10 +60,32 @@ static int omap5_usb_phy_power(struct omap_usb *phy, bool on) val = readl(phy->control_dev); + val &= ~(USB_PWRCTL_CLK_CMD_MASK | USB_PWRCTL_CLK_FREQ_MASK); + val |= (USB3_PHY_PARTIAL_RX_POWERON | USB3_PHY_TX_RX_POWERON) + << USB_PWRCTL_CLK_CMD_SHIFT; + val |= rate << USB_PWRCTL_CLK_FREQ_SHIFT; + + writel(val, phy->control_dev); + + return 0; +} + +/** + * omap5_usb_phy_power - power on/off the serializer using control module + * @phy: struct omap_usb * + * @on: 0 to off and 1 to on based on powering on or off the PHY + * + * omap_usb3 can call this API to power on or off the PHY. + */ +static int omap5_usb_phy_power(struct omap_usb *phy, bool on) +{ + u32 val; + + val = readl(phy->control_dev); + if (on) { - val &= ~(USB_PWRCTL_CLK_CMD_MASK | USB_PWRCTL_CLK_FREQ_MASK); + val &= ~USB_PWRCTL_CLK_CMD_MASK; val |= USB3_PHY_TX_RX_POWERON << USB_PWRCTL_CLK_CMD_SHIFT; - val |= rate << USB_PWRCTL_CLK_FREQ_SHIFT; } else { val &= ~USB_PWRCTL_CLK_CMD_MASK; val |= USB3_PHY_TX_RX_POWEROFF << USB_PWRCTL_CLK_CMD_SHIFT; @@ -207,6 +231,13 @@ static int omap_usb3_init(struct usb_phy *x) struct omap_usb *phy = phy_to_omapusb(x); omap_usb_dpll_lock(phy); + omap5_usb_phy_partial_powerup(phy); + /* + * Give enough time for the PHY to partially power-up before + * powering it up completely. delay value suggested by the HW + * team. + */ + mdelay(100); omap5_usb_phy_power(phy, 1); return 0; diff --git a/include/linux/usb/omap_usb.h b/include/linux/usb/omap_usb.h index 01ed008..62b637c 100644 --- a/include/linux/usb/omap_usb.h +++ b/include/linux/usb/omap_usb.h @@ -92,6 +92,7 @@ struct omap_usb { #define USB3_PHY_TX_RX_POWERON 0x3 #define USB3_PHY_TX_RX_POWEROFF 0x0 +#define USB3_PHY_PARTIAL_RX_POWERON (0x1 << 6) #define phy_to_omapusb(x) container_of((x), struct omap_usb, phy) -- 1.7.9.5