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SubjectRe: [PATCH v4 3/3] phy: omap-usb2-phy: disable PHY charger detect
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On 19/08/2020 12:02, Jan Kiszka wrote:
> On 16.07.20 10:22, Roger Quadros wrote:
>> AM654x PG1.0 has a silicon bug that D+ is pulled high after POR, which
>> could cause enumeration failure with some USB hubs. Disabling the
>> USB2_PHY Charger Detect function will put D+ into the normal state.
>>
>> Using property "ti,disable-charger-det" in the DT usb2-phy node to
>> enable this workaround for AM654x PG1.0.
>>
>> This addresses Silicon Errata:
>> i2075 - "USB2PHY: USB2PHY Charger Detect is Enabled by Default Without VBUS
>> Presence"
>>
>> Signed-off-by: Bin Liu <b-liu@ti.com>
>> Signed-off-by: Sekhar Nori <nsekhar@ti.com>
>> Signed-off-by: Roger Quadros <rogerq@ti.com>
>> ---
>> drivers/phy/ti/phy-omap-usb2.c | 35 +++++++++++++++++++++++++++-------
>> 1 file changed, 28 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/phy/ti/phy-omap-usb2.c b/drivers/phy/ti/phy-omap-usb2.c
>> index cb2dd3230fa7..21c3904d4efc 100644
>> --- a/drivers/phy/ti/phy-omap-usb2.c
>> +++ b/drivers/phy/ti/phy-omap-usb2.c
>> @@ -26,6 +26,10 @@
>> #define USB2PHY_ANA_CONFIG1 0x4c
>> #define USB2PHY_DISCON_BYP_LATCH BIT(31)
>>
>> +#define USB2PHY_CHRG_DET 0x14
>> +#define USB2PHY_CHRG_DET_USE_CHG_DET_REG BIT(29)
>> +#define USB2PHY_CHRG_DET_DIS_CHG_DET BIT(28)
>> +
>> /* SoC Specific USB2_OTG register definitions */
>> #define AM654_USB2_OTG_PD BIT(8)
>> #define AM654_USB2_VBUS_DET_EN BIT(5)
>> @@ -43,6 +47,7 @@
>> #define OMAP_USB2_HAS_START_SRP BIT(0)
>> #define OMAP_USB2_HAS_SET_VBUS BIT(1)
>> #define OMAP_USB2_CALIBRATE_FALSE_DISCONNECT BIT(2)
>> +#define OMAP_USB2_DISABLE_CHRG_DET BIT(3)
>>
>> struct omap_usb {
>> struct usb_phy phy;
>> @@ -236,6 +241,13 @@ static int omap_usb_init(struct phy *x)
>> omap_usb_writel(phy->phy_base, USB2PHY_ANA_CONFIG1, val);
>> }
>>
>> + if (phy->flags & OMAP_USB2_DISABLE_CHRG_DET) {
>> + val = omap_usb_readl(phy->phy_base, USB2PHY_CHRG_DET);
>> + val |= USB2PHY_CHRG_DET_USE_CHG_DET_REG |
>> + USB2PHY_CHRG_DET_DIS_CHG_DET;
>> + omap_usb_writel(phy->phy_base, USB2PHY_CHRG_DET, val);
>> + }
>> +
>> return 0;
>> }
>>
>> @@ -366,14 +378,12 @@ static int omap_usb2_probe(struct platform_device *pdev)
>> phy->mask = phy_data->mask;
>> phy->power_on = phy_data->power_on;
>> phy->power_off = phy_data->power_off;
>> + phy->flags = phy_data->flags;
>>
>> - if (phy_data->flags & OMAP_USB2_CALIBRATE_FALSE_DISCONNECT) {
>> - res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> - phy->phy_base = devm_ioremap_resource(&pdev->dev, res);
>> - if (IS_ERR(phy->phy_base))
>> - return PTR_ERR(phy->phy_base);
>> - phy->flags |= OMAP_USB2_CALIBRATE_FALSE_DISCONNECT;
>> - }
>> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> + phy->phy_base = devm_ioremap_resource(&pdev->dev, res);
>> + if (IS_ERR(phy->phy_base))
>> + return PTR_ERR(phy->phy_base);
>>
>> phy->syscon_phy_power = syscon_regmap_lookup_by_phandle(node,
>> "syscon-phy-power");
>> @@ -405,6 +415,17 @@ static int omap_usb2_probe(struct platform_device *pdev)
>> }
>> }
>>
>> + /*
>> + * Errata i2075: USB2PHY: USB2PHY Charger Detect is Enabled by
>> + * Default Without VBUS Presence.
>> + *
>> + * AM654x SR1.0 has a silicon bug due to which D+ is pulled high after
>> + * POR, which could cause enumeration failure with some USB hubs.
>> + * Disabling the USB2_PHY Charger Detect function will put D+
>> + * into the normal state.
>> + */
>> + if (of_property_read_bool(node, "ti,disable-charger-det"))
>> + phy->flags |= OMAP_USB2_DISABLE_CHRG_DET;
>>
>> phy->wkupclk = devm_clk_get(phy->dev, "wkupclk");
>> if (IS_ERR(phy->wkupclk)) {
>>
>
> Why a property, rather than SoC detection like in [1] and your previous
> downstream version?

I agree, that SoC detection is better way. Will spin a v5.

>
> Jan
>
> [1] https://patchwork.kernel.org/patch/11710643/
>

cheers,
-roger
--
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki

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