On 23-05-2019 15:31, Thierry Reding wrote:
> On Thu, May 16, 2019 at 12:09:26PM +0530, Nagarjuna Kristam wrote:
>> On Tegra210, usb2 only otg/peripheral ports dont work in device mode.
>> They need an assosciated usb3 port to work in device mode. Identify
>> an unused usb3 port and assign it as a fake USB3 port to USB2 only
>> port whose mode is otg/peripheral.
>>
>> Based on work by BH Hsieh <bhsieh@xxxxxxxxxx>.
>>
>> Signed-off-by: Nagarjuna Kristam <nkristam@xxxxxxxxxx>
>> ---
>> drivers/phy/tegra/xusb-tegra210.c | 56 +++++++++++++++++++++++++++++++
>> drivers/phy/tegra/xusb.c | 69 +++++++++++++++++++++++++++++++++++++++
>> drivers/phy/tegra/xusb.h | 2 ++
>> 3 files changed, 127 insertions(+)
>>
>> diff --git a/drivers/phy/tegra/xusb-tegra210.c b/drivers/phy/tegra/xusb-tegra210.c
>> index 4beebcc..829aca5 100644
>> --- a/drivers/phy/tegra/xusb-tegra210.c
>> +++ b/drivers/phy/tegra/xusb-tegra210.c
>> @@ -58,6 +58,7 @@
>> #define XUSB_PADCTL_SS_PORT_MAP_PORTX_MAP_SHIFT(x) ((x) * 5)
>> #define XUSB_PADCTL_SS_PORT_MAP_PORTX_MAP_MASK(x) (0x7 << ((x) * 5))
>> #define XUSB_PADCTL_SS_PORT_MAP_PORTX_MAP(x, v) (((v) & 0x7) << ((x) * 5))
>> +#define XUSB_PADCTL_SS_PORT_MAP_PORT_DISABLED 0x7
>>
>> #define XUSB_PADCTL_ELPG_PROGRAM1 0x024
>> #define XUSB_PADCTL_ELPG_PROGRAM1_AUX_MUX_LP0_VCORE_DOWN (1 << 31)
>> @@ -952,6 +953,34 @@ static int tegra210_usb2_phy_power_on(struct phy *phy)
>>
>> priv = to_tegra210_xusb_padctl(padctl);
>>
>> + if (port->usb3_port_fake != -1) {
>> + value = padctl_readl(padctl, XUSB_PADCTL_SS_PORT_MAP);
>> + value &= ~XUSB_PADCTL_SS_PORT_MAP_PORTX_MAP_MASK(
>> + port->usb3_port_fake);
>> + value |= XUSB_PADCTL_SS_PORT_MAP_PORTX_MAP(
>> + port->usb3_port_fake, index);
>> + padctl_writel(padctl, value, XUSB_PADCTL_SS_PORT_MAP);
>> +
>> + value = padctl_readl(padctl, XUSB_PADCTL_ELPG_PROGRAM1);
>> + value &= ~XUSB_PADCTL_ELPG_PROGRAM1_SSPX_ELPG_VCORE_DOWN(
>> + port->usb3_port_fake);
>> + padctl_writel(padctl, value, XUSB_PADCTL_ELPG_PROGRAM1);
>> +
>> + usleep_range(100, 200);
>> +
>> + value = padctl_readl(padctl, XUSB_PADCTL_ELPG_PROGRAM1);
>> + value &= ~XUSB_PADCTL_ELPG_PROGRAM1_SSPX_ELPG_CLAMP_EN_EARLY(
>> + port->usb3_port_fake);
>> + padctl_writel(padctl, value, XUSB_PADCTL_ELPG_PROGRAM1);
>> +
>> + usleep_range(100, 200);
>> +
>> + value = padctl_readl(padctl, XUSB_PADCTL_ELPG_PROGRAM1);
>> + value &= ~XUSB_PADCTL_ELPG_PROGRAM1_SSPX_ELPG_CLAMP_EN(
>> + port->usb3_port_fake);
>> + padctl_writel(padctl, value, XUSB_PADCTL_ELPG_PROGRAM1);
>> + }
>> +
>> value = padctl_readl(padctl, XUSB_PADCTL_USB2_BIAS_PAD_CTL0);
>> value &= ~((XUSB_PADCTL_USB2_BIAS_PAD_CTL0_HS_SQUELCH_LEVEL_MASK <<
>> XUSB_PADCTL_USB2_BIAS_PAD_CTL0_HS_SQUELCH_LEVEL_SHIFT) |
>> @@ -1086,6 +1115,32 @@ static int tegra210_usb2_phy_power_off(struct phy *phy)
>>
>> mutex_lock(&padctl->lock);
>>
>> + if (port->usb3_port_fake != -1) {
>> + value = padctl_readl(padctl, XUSB_PADCTL_ELPG_PROGRAM1);
>> + value |= XUSB_PADCTL_ELPG_PROGRAM1_SSPX_ELPG_CLAMP_EN_EARLY(
>> + port->usb3_port_fake);
>> + padctl_writel(padctl, value, XUSB_PADCTL_ELPG_PROGRAM1);
>> +
>> + usleep_range(100, 200);
>> +
>> + value = padctl_readl(padctl, XUSB_PADCTL_ELPG_PROGRAM1);
>> + value |= XUSB_PADCTL_ELPG_PROGRAM1_SSPX_ELPG_CLAMP_EN(
>> + port->usb3_port_fake);
>> + padctl_writel(padctl, value, XUSB_PADCTL_ELPG_PROGRAM1);
>> +
>> + usleep_range(250, 350);
>> +
>> + value = padctl_readl(padctl, XUSB_PADCTL_ELPG_PROGRAM1);
>> + value |= XUSB_PADCTL_ELPG_PROGRAM1_SSPX_ELPG_VCORE_DOWN(
>> + port->usb3_port_fake);
>> + padctl_writel(padctl, value, XUSB_PADCTL_ELPG_PROGRAM1);
>> +
>> + value = padctl_readl(padctl, XUSB_PADCTL_SS_PORT_MAP);
>> + value |= XUSB_PADCTL_SS_PORT_MAP_PORTX_MAP(port->usb3_port_fake,
>> + XUSB_PADCTL_SS_PORT_MAP_PORT_DISABLED);
>> + padctl_writel(padctl, value, XUSB_PADCTL_SS_PORT_MAP);
>> + }
>> +
>> if (WARN_ON(pad->enable == 0))
>> goto out;
>>
>> @@ -2051,6 +2106,7 @@ const struct tegra_xusb_padctl_soc tegra210_xusb_padctl_soc = {
>> },
>> },
>> .ops = &tegra210_xusb_padctl_ops,
>> + .need_fake_usb3_port = true,
>> };
>> EXPORT_SYMBOL_GPL(tegra210_xusb_padctl_soc);
>>
>> diff --git a/drivers/phy/tegra/xusb.c b/drivers/phy/tegra/xusb.c
>> index 0417213..6618db7 100644
>> --- a/drivers/phy/tegra/xusb.c
>> +++ b/drivers/phy/tegra/xusb.c
>> @@ -808,9 +808,66 @@ static void __tegra_xusb_remove_ports(struct tegra_xusb_padctl *padctl)
>> }
>> }
>>
>> +static int tegra_xusb_find_unused_usb3_port(struct tegra_xusb_padctl *padctl)
>> +{
>> + struct device_node *np;
>> + unsigned int i;
>> +
>> + for (i = 0; i < padctl->soc->ports.usb3.count; i++) {
>> + np = tegra_xusb_find_port_node(padctl, "usb3", i);
>> + if (!np || !of_device_is_available(np))
>> + return i;
>> + }
>> +
>> + return -ENODEV;
>> +}
>> +
>> +static bool tegra_xusb_usb3_port_has_companion(struct tegra_xusb_padctl *padctl,
>> + unsigned int index)
>> +{
>> + unsigned int i;
>> + struct tegra_xusb_usb3_port *usb3;
>> +
>> + for (i = 0; i < padctl->soc->ports.usb3.count; i++) {
>> + usb3 = tegra_xusb_find_usb3_port(padctl, i);
>> + if (usb3 && usb3->port == index)
>> + return true;
>> + }
>> +
>> + return false;
>> +}
>> +
>> +static int tegra_xusb_update_usb3_fake_port(struct tegra_xusb_usb2_port *usb2)
>> +{
>> + int fake;
>> +
>> + /* Disable usb3_port_fake usage by default and assign if needed */
>> + usb2->usb3_port_fake = -1;
>> +
>> + if ((usb2->mode == USB_DR_MODE_OTG ||
>> + usb2->mode == USB_DR_MODE_PERIPHERAL) &&
>> + !tegra_xusb_usb3_port_has_companion(usb2->base.padctl,
>> + usb2->base.index)) {
>
> This port is still a bit confusing to me. It's not entirely obvious
> what's going on here. What I think this is doing is this: for OTG or
> peripheral USB 2.0 ports that are not companion ports themselves (i.e.
> only standalone OTG/peripheral USB 2.0 ports) find an unused USB 3.0
> port that can be used as fake for the hardware workaround.
>
> Correct me if I'm wrong.
>
Yes, understanding is correct
> I find the tegra_xusb_usb3_port_has_companion() confusing in that case
> because you seem to be testing a USB 3.0 port (_usb3_ in the function
> name) for a USB 2.0 index (passed as second parameter). So what you're
> basically trying to do is find a USB 3.0 port for which the USB 2.0 port
> identified by the given index is a companion. It seems to me like that
> would be a lot easier to understand if you did this:
>
> !tegra_xusb_usb2_port_is_companion(usb2)
>
> with:
>
> static bool tegra_xusb_port_is_companion(struct tegra_xusb_usb2_port *port)
> {
> struct tegra_xusb_padctl *padctl = port->base.padctl;
> struct tegra_xusb_usb3_port *usb3;
> unsigned int i;
>
> for (i = 0; i < padctl->soc->ports.usb3.count; i++) {
> usb3 = tegra_xusb_find_usb3_port(padctl, i);
> if (usb3 && usb3->port == port->base.index)
> return true;
> }
>
> return false;
> }
>
Will update accordingly
>> +
>> + fake = tegra_xusb_find_unused_usb3_port(usb2->base.padctl);
>> +
>> + if (fake < 0) {
>
> This is one of the few exceptions where the blank line is not useful. It
> makes sense here to keep the above two lines close together because you
> assign the value and then check it. So the blank line rule doesn't apply
> to this general pattern:
>
> value = foobar(...);
> if (value < 0) {
> ...
> }
>
> That is, if the value that you check is the same that you just assigned,
> you should avoid the blank line as separator because the two lines are
> closely related.
>
Will update accordingly
>> + dev_err(&usb2->base.dev, "no unused USB3 ports available\n");
>> + return -ENODEV;
>> + }
>> +
>> + dev_dbg(&usb2->base.dev, "Found unused usb3 port: %d\n",
>> + fake);
>
> Nit: the above fits on a single line.
>
> Otherwise looks good.
>
> Thierry
>
Will update accordingly
-Nagarjuna
>> + usb2->usb3_port_fake = fake;
>> + tegra_xusb_find_unused_usb3_port(usb2->base.padctl);
>> + }
>> +
>> + return 0;
>> +}
>> +
>> static int tegra_xusb_setup_ports(struct tegra_xusb_padctl *padctl)
>> {
>> struct tegra_xusb_port *port;
>> + struct tegra_xusb_usb2_port *usb2;
>> unsigned int i;
>> int err = 0;
>>
>> @@ -840,6 +897,18 @@ static int tegra_xusb_setup_ports(struct tegra_xusb_padctl *padctl)
>> goto remove_ports;
>> }
>>
>> + if (padctl->soc->need_fake_usb3_port) {
>> + for (i = 0; i < padctl->soc->ports.usb2.count; i++) {
>> + usb2 = tegra_xusb_find_usb2_port(padctl, i);
>> + if (!usb2)
>> + continue;
>> +
>> + err = tegra_xusb_update_usb3_fake_port(usb2);
>> + if (err < 0)
>> + goto remove_ports;
>> + }
>> + }
>> +
>> list_for_each_entry(port, &padctl->ports, list) {
>> err = port->ops->enable(port);
>> if (err < 0)
>> diff --git a/drivers/phy/tegra/xusb.h b/drivers/phy/tegra/xusb.h
>> index e0028b9f..26dd6d2 100644
>> --- a/drivers/phy/tegra/xusb.h
>> +++ b/drivers/phy/tegra/xusb.h
>> @@ -299,6 +299,7 @@ struct tegra_xusb_usb2_port {
>> struct regulator *supply;
>> enum usb_dr_mode mode;
>> bool internal;
>> + int usb3_port_fake;
>> };
>>
>> static inline struct tegra_xusb_usb2_port *
>> @@ -397,6 +398,7 @@ struct tegra_xusb_padctl_soc {
>>
>> const char * const *supply_names;
>> unsigned int num_supplies;
>> + bool need_fake_usb3_port;
>> };
>>
>> struct tegra_xusb_padctl {
>> --
>> 2.7.4
>>
