RE: [PATCH] mx8mm: usb: chipidea: Fix Battery Charger 1.2 CDP detection

[Jun Li <jun.li@nxp.com>]

> -----Original Message-----
> From: Breno Matheus Lima <breno.lima@nxp.com>
> Sent: Friday, June 11, 2021 9:48 AM
> To: peter.chen@kernel.org
> Cc: gregkh@linuxfoundation.org; shawnguo@kernel.org;
> s.hauer@pengutronix.de; kernel@pengutronix.de; festevam@gmail.com;
> dl-linux-imx <linux-imx@nxp.com>; linux-usb@vger.kernel.org;
> linux-arm-kernel@lists.infradead.org; linux-kernel@vger.kernel.org;
> brenomatheus@gmail.com; Jun Li <jun.li@nxp.com>; Breno Matheus Lima
> <breno.lima@nxp.com>
> Subject: [PATCH] mx8mm: usb: chipidea: Fix Battery Charger 1.2 CDP detection
> 
> i.MX8MM cannot detect certain CDP USB HUBs. usbmisc_imx.c driver is not
> following CDP timing requirements defined by USB BC 1.2 specification and
> section 3.2.4 Detection Timing CDP.
> 
> During Primary Detection the i.MX device should turn on VDP_SRC and IDM_SINK
> for a minimum of 40ms (TVDPSRC_ON). After a time of TVDPSRC_ON, the PD is
> allowed to check the status of the D- line. Current implementation is waiting
> between 1ms and 2ms, and certain BC 1.2 complaint USB HUBs cannot be detected.
> Increase delay to 40ms allowing enough time for primary detection.
> 
> During secondary detection the PD is required to disable VDP_SRC and IDM_SNK,
> and enable VDM_SRC and IDP_SINK for at least 40ms (TVDMSRC_ON).
> 
> Current implementation is not disabling VDP_SRC and IDM_SNK, introduce
> disable sequence in imx7d_charger_secondary_detection() function.
> 
> VDM_SRC and IDP_SINK should be enabled for at least 40ms (TVDMSRC_ON).
> Increase delay allowing enough time for detection.
> 

Fixes: 746f316b753a ("usb: chipidea: introduce imx7d USB charger detection")

> Signed-off-by: Breno Lima <breno.lima@nxp.com>
> Signed-off-by: Jun Li <jun.li@nxp.com>
> ---
>  drivers/usb/chipidea/usbmisc_imx.c | 16 ++++++++++++++--
>  1 file changed, 14 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/usb/chipidea/usbmisc_imx.c
> b/drivers/usb/chipidea/usbmisc_imx.c
> index 4545b23bda3f..bac0f5458cab 100644
> --- a/drivers/usb/chipidea/usbmisc_imx.c
> +++ b/drivers/usb/chipidea/usbmisc_imx.c
> @@ -686,6 +686,16 @@ static int imx7d_charger_secondary_detection(struct
> imx_usbmisc_data *data)
>  	int val;
>  	unsigned long flags;
> 
> +	/* Clear VDATSRCENB0 to disable VDP_SRC and IDM_SNK required by BC 1.2
> spec */
> +	spin_lock_irqsave(&usbmisc->lock, flags);
> +	val = readl(usbmisc->base + MX7D_USB_OTG_PHY_CFG2);
> +	val &= ~MX7D_USB_OTG_PHY_CFG2_CHRG_VDATSRCENB0;
> +	writel(val, usbmisc->base + MX7D_USB_OTG_PHY_CFG2);
> +	spin_unlock_irqrestore(&usbmisc->lock, flags);
> +
> +	/* TVDMSRC_DIS */
> +	msleep(20);
> +
>  	/* VDM_SRC is connected to D- and IDP_SINK is connected to D+ */
>  	spin_lock_irqsave(&usbmisc->lock, flags);
>  	val = readl(usbmisc->base + MX7D_USB_OTG_PHY_CFG2); @@ -695,7 +705,8
> @@ static int imx7d_charger_secondary_detection(struct imx_usbmisc_data
> *data)
>  				usbmisc->base + MX7D_USB_OTG_PHY_CFG2);
>  	spin_unlock_irqrestore(&usbmisc->lock, flags);
> 
> -	usleep_range(1000, 2000);
> +	/* TVDMSRC_ON */
> +	msleep(40);
> 
>  	/*
>  	 * Per BC 1.2, check voltage of D+:
> @@ -798,7 +809,8 @@ static int imx7d_charger_primary_detection(struct
> imx_usbmisc_data *data)
>  				usbmisc->base + MX7D_USB_OTG_PHY_CFG2);
>  	spin_unlock_irqrestore(&usbmisc->lock, flags);
> 
> -	usleep_range(1000, 2000);
> +	/* TVDPSRC_ON */
> +	msleep(40);
> 
>  	/* Check if D- is less than VDAT_REF to determine an SDP per BC 1.2 */
>  	val = readl(usbmisc->base + MX7D_USB_OTG_PHY_STATUS);
> --
> 2.25.1


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