Hi Vinod,

  Thank you for the review comments...

On 24/8/2020 12:06 am, Vinod Koul wrote:
On 17-08-20, 15:05, Ramuthevar,Vadivel MuruganX wrote:
From: Ramuthevar Vadivel Murugan <[email protected]>

Add support for USB PHY on Intel LGM SoC.

Signed-off-by: Ramuthevar Vadivel Murugan 
<[email protected]>
Reviewed-by: Philipp Zabel <[email protected]>
---
  drivers/phy/Kconfig       |  11 ++
  drivers/phy/Makefile      |   1 +
  drivers/phy/phy-lgm-usb.c | 278 ++++++++++++++++++++++++++++++++++++++++++++++
  3 files changed, 290 insertions(+)
  create mode 100644 drivers/phy/phy-lgm-usb.c

diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
index de9362c25c07..01b53f86004c 100644
--- a/drivers/phy/Kconfig
+++ b/drivers/phy/Kconfig
@@ -49,6 +49,17 @@ config PHY_XGENE
        help
          This option enables support for APM X-Gene SoC multi-purpose PHY.
+config USB_LGM_PHY
+       tristate "INTEL Lightning Mountain USB PHY Driver"
+       depends on USB_SUPPORT

Why is the dependent on USB..? Should that not be other way around?
Good catch, it's not required.

+static int get_flipped(struct tca_apb *ta, bool *flipped)
+{
+       union extcon_property_value property;
+       int ret;
+
+       ret = extcon_get_property(ta->phy.edev, EXTCON_USB_HOST,
+                                 EXTCON_PROP_USB_TYPEC_POLARITY, &property);
+       if (ret) {
+               dev_err(ta->phy.dev, "no polarity property from extcon\n");
+               return ret;
+       }
+
+       *flipped = property.intval;
+
+       return ret;

return 0 here?
Noted.

+static int phy_init(struct usb_phy *phy)
+{
+       struct tca_apb *ta = container_of(phy, struct tca_apb, phy);
+       void __iomem *ctrl1 = phy->io_priv + CTRL1_OFFSET;
+       int val, ret, i;
+
+       if (ta->phy_initialized)
+               return 0;
+
+       for (i = 0; i < ARRAY_SIZE(PHY_RESETS); i++)
+               reset_control_deassert(ta->resets[i]);
+
+       ret = readl_poll_timeout(ctrl1, val, val & SRAM_INIT_DONE, 10, 10 * 
1000);
+       if (ret) {
+               dev_err(ta->phy.dev, "SRAM init failed, 0x%x\n", val);
+               return ret;
+       }
+
+       writel(readl(ctrl1) | SRAM_EXT_LD_DONE, ctrl1);
+
+       ta->phy_initialized = true;
+       if (!ta->phy.edev) {
+               writel(TCPC_CONN, ta->phy.io_priv + TCPC_OFFSET);
+               return phy->set_vbus(phy, true);
+       }
+
+       schedule_work(&ta->wk);

why work for init?
Yes, it's required during the reboot and already device is connected status update to controller, well tested.

+static void tca_work(struct work_struct *work)
+{
+       struct tca_apb *ta = container_of(work, struct tca_apb, wk);
+       bool connected;
+       bool flipped = false;
+       u32 val;
+       int ret;
+
+       ret = get_flipped(ta, &flipped);

so every time this work is scheduled you are reading from firmware, why..
Typically we should read in probe and store it..

+       connected = extcon_get_state(ta->phy.edev, EXTCON_USB_HOST) && !ret;

lets handle ret and extcon_get_state separately please
Sure, we can handle it separately.

+       if (connected == ta->connected)
+               return;
+
+       ta->connected = connected;
+       if (connected) {
+               val = TCPC_CONN;
+               if (flipped)
+                       val |= TCPC_FLIPPED;
+               dev_info(ta->phy.dev, "connected%s\n", flipped ? " flipped" : 
"");

debug perhaps
Noted.

+       } else {
+               val = TCPC_DISCONN;
+               dev_info(ta->phy.dev, "disconnected\n");

here too
Noted.

+static int vbus_notifier(struct notifier_block *nb, unsigned long evnt, void 
*ptr)
+{
+       return NOTIFY_DONE;
+}

empty notifier, why bother?
Let me check and double confirm if it's required or not.

+static int phy_probe(struct platform_device *pdev)
+{
+       struct reset_control *resets[ARRAY_SIZE(CTL_RESETS)];
+       struct device *dev = &pdev->dev;
+       struct usb_phy *phy;
+       struct tca_apb *ta;
+       int i;
+
+       ta = devm_kzalloc(dev, sizeof(*ta), GFP_KERNEL);
+       if (!ta)
+               return -ENOMEM;
+
+       platform_set_drvdata(pdev, ta);
+       INIT_WORK(&ta->wk, tca_work);
+
+       phy = &ta->phy;
+       phy->dev = dev;
+       phy->label = dev_name(dev);
+       phy->type = USB_PHY_TYPE_USB3;
+       phy->init = phy_init;
+       phy->shutdown = phy_shutdown;
+       phy->set_vbus = phy_set_vbus;
+       phy->id_nb.notifier_call = id_notifier;
+       phy->vbus_nb.notifier_call = vbus_notifier;
+
+       phy->io_priv = devm_platform_ioremap_resource(pdev, 0);
+       if (IS_ERR(phy->io_priv))
+               return PTR_ERR(phy->io_priv);
+
+       ta->vbus = devm_regulator_get(dev, "vbus");
+       if (IS_ERR(ta->vbus))
+               return PTR_ERR(ta->vbus);
+
+       for (i = 0; i < ARRAY_SIZE(CTL_RESETS); i++) {
+               resets[i] = devm_reset_control_get_exclusive(dev, 
CTL_RESETS[i]);
+               if (IS_ERR(resets[i])) {
+                       dev_err(dev, "%s reset not found\n", CTL_RESETS[i]);
+                       return PTR_ERR(resets[i]);
+               }
+       }
+
+       for (i = 0; i < ARRAY_SIZE(PHY_RESETS); i++) {
+               ta->resets[i] = devm_reset_control_get_exclusive(dev, 
PHY_RESETS[i]);
+               if (IS_ERR(ta->resets[i])) {
+                       dev_err(dev, "%s reset not found\n", PHY_RESETS[i]);
+                       return PTR_ERR(ta->resets[i]);
+               }
+       }
+
+       for (i = 0; i < ARRAY_SIZE(CTL_RESETS); i++)
+               reset_control_assert(resets[i]);
+
+       for (i = 0; i < ARRAY_SIZE(PHY_RESETS); i++)
+               reset_control_assert(ta->resets[i]);

no time lag b/w assert and dessert below?
yes you're right but not required for Intel LGM SoC, it's working fine.

Regards
Vadivel

+       /*
+        * Out-of-band reset of the controller after PHY reset will cause
+        * controller malfunctioning, so we should use in-band controller
+        * reset only and leave the controller de-asserted here.
+        */
+       for (i = 0; i < ARRAY_SIZE(CTL_RESETS); i++)
+               reset_control_deassert(resets[i]);
+
+       /* Need to wait at least 20us after de-assert the controller */
+       usleep_range(20, 100);
+
+       return usb_add_phy_dev(phy);

aha, this is usb_phy stuff.

Kishon this is not really a generic phy driver, should it be in
drivers/phy..?

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