On 25-04-2019 20:25, Thierry Reding wrote:
> On Mon, Mar 11, 2019 at 04:41:50PM +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 | 40 +++++++++++++++++++++++++++++++++++++++
>> drivers/phy/tegra/xusb.c | 29 ++++++++++++++++++++++++++++
>> drivers/phy/tegra/xusb.h | 6 ++++++
>> 3 files changed, 75 insertions(+)
>
> I think this looks a whole lot better than the initial version. One or
> two minor comments below.
>
>> diff --git a/drivers/phy/tegra/xusb-tegra210.c b/drivers/phy/tegra/xusb-tegra210.c
>> index 4beebcc..48478bc4 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 +953,15 @@ 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_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 +1096,15 @@ 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_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,
>> + XUSB_PADCTL_SS_PORT_MAP_PORT_DISABLED);
>> + padctl_writel(padctl, value, XUSB_PADCTL_SS_PORT_MAP);
>> + }
>> +
>> if (WARN_ON(pad->enable == 0))
>> goto out;
>>
>> @@ -1784,6 +1803,27 @@ static const struct tegra_xusb_pad_soc * const tegra210_pads[] = {
>>
>> static int tegra210_usb2_port_enable(struct tegra_xusb_port *port)
>> {
>> + struct tegra_xusb_usb2_port *usb2 = to_usb2_port(port);
>> + struct tegra_xusb_padctl *padctl = port->padctl;
>> +
>> + /* Disable usb3_port_fake usage by default and assign if needed */
>> + usb2->usb3_port_fake = -1;
>> + if (usb2 && (usb2->mode == USB_DR_MODE_OTG ||
>> + usb2->mode == USB_DR_MODE_PERIPHERAL)) {
>> + if (!tegra_xusb_usb3_port_has_companion(padctl, port->index)) {
>> + int fake = tegra_xusb_find_unused_usb3_port(padctl);
>> +
>> + if (fake >= 0) {
>> + dev_dbg(&port->dev, "Found unused usb3 port: %d\n",
>> + fake);
>> + usb2->usb3_port_fake = fake;
>> + } else {
>> + dev_err(&port->dev, "usb2-%u has neither a companion nor an unused usb3 port to fake it\n",
>> + port->index);
>> + return -ENODEV;
>> + }
>> + }
>> + }
>
> Generally it's preferable to check for errors and deal with success in
> the regular code path. So the above would be:
>
> if (fake < 0) {
> dev_err(...);
> return -ENODEV;
> }
>
> dev_dbg(...);
> ...
>
> Also, the error message is slightly redundant because &port->dev will
> already output the usb2-%u part. Also, perhaps try to make that message
> a little shorter. Something like:
>
> dev_err(&port->dev, "no unused USB3 ports available\n");
>
Will update accordingly
> Also, I don't think this is the right place to do this. There's really
> no way for the ->enable() callbacks to fail. Or at least failures will
> be ignored, so there's no chance for the driver to do anything about the
> failure. It also looks somewhat tacked on.
>
> But how about if we do this as part of tegra_xusb_usb3_port_parse_dt()
> or tegra_xusb_add_usb3_port() already? The former is where we read the
> USB2 companion port index from DT so we know exactly which USB2 port to
> associate with a given USB3 port. So in the latter we could iterate over
> the USB2 ports (which have already been set up) and establish a backlink
> to the USB3 companion.
>
Ok, instead of doing in ->enable(), will move the logic currently inside ->enable()
to a separate function called from tegra_xusb_setup_ports(). This will get executed
under soc flag need_fake_usb3_support, which will be set only in t210 soc data.
> Something like this, in tegra_xusb_add_usb3_port():
>
> struct tegra_xusb_usb2_port *companion;
>
> for (i = 0; i < padctl->soc->ports.usb2.count; i++) {
> companion = tegra_xusb_find_usb2_port(padctl, i);
> if (!companion)
> continue;
>
> if (companion->base.index == usb3->port) {
> companion->port = index;
> break;
> }
> }
>
> Then, as part of tegra_xusb_setup_ports() we could add functionality to
> hook up a fake port if no companion is available, much like you're doing
> above. Perhaps we should introduce a new ->setup() callback to the port
> ops to encapsulate this, or perhaps add a flag to tegra_xusb_padctl_soc
> that is set to true on SoC generations that need the fake USB3 port.
>
> Thierry
I believe adding usb3 port index data to usb2 port data structure is not needed.
Logic inside current ->enable() [which will be moved based on soc data feature flag]
takes care of the needs.
- Nagarjuna
>
>> return 0;
>> }
>>
>> diff --git a/drivers/phy/tegra/xusb.c b/drivers/phy/tegra/xusb.c
>> index c6178a0..e89746d 100644
>> --- a/drivers/phy/tegra/xusb.c
>> +++ b/drivers/phy/tegra/xusb.c
>> @@ -799,6 +799,35 @@ static void __tegra_xusb_remove_ports(struct tegra_xusb_padctl *padctl)
>> }
>> }
>>
>> +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;
>> +}
>> +
>> +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 int tegra_xusb_setup_ports(struct tegra_xusb_padctl *padctl)
>> {
>> struct tegra_xusb_port *port;
>> diff --git a/drivers/phy/tegra/xusb.h b/drivers/phy/tegra/xusb.h
>> index 17cc8dc..b263165 100644
>> --- a/drivers/phy/tegra/xusb.h
>> +++ b/drivers/phy/tegra/xusb.h
>> @@ -274,6 +274,7 @@ struct tegra_xusb_usb2_port {
>> struct regulator *supply;
>> bool internal;
>> enum usb_dr_mode mode;
>> + int usb3_port_fake;
>> };
>>
>> static inline struct tegra_xusb_usb2_port *
>> @@ -413,6 +414,11 @@ struct tegra_xusb_lane *tegra_xusb_find_lane(struct tegra_xusb_padctl *padctl,
>> const char *name,
>> unsigned int index);
>>
>> +bool tegra_xusb_usb3_port_has_companion(struct tegra_xusb_padctl *padctl,
>> + unsigned int index);
>> +
>> +int tegra_xusb_find_unused_usb3_port(struct tegra_xusb_padctl *padctl);
>> +
>> #if defined(CONFIG_ARCH_TEGRA_124_SOC) || defined(CONFIG_ARCH_TEGRA_132_SOC)
>> extern const struct tegra_xusb_padctl_soc tegra124_xusb_padctl_soc;
>> #endif
>> --
>> 2.7.4
>>
