Re: [PATCH V2 5/8] phy: tegra: xusb: Add soc ops API to enable UTMI PAD protection

From: Nagarjuna Kristam
Date: Mon May 04 2020 - 06:24:40 EST



On 28-04-2020 15:45, Thierry Reding wrote:
On Wed, Apr 15, 2020 at 01:55:05PM +0530, Nagarjuna Kristam wrote:
When USB charger is enabled, UTMI PAD needs to be protected according
to the direction and current level. Add support for the same on Tegra210
and Tegra186.

Signed-off-by: Nagarjuna Kristam<nkristam@xxxxxxxxxx>
---
V2:
- Commit message coorected.
- Patch re-based.
---
drivers/phy/tegra/xusb-tegra186.c | 40 +++++++++++++++++++++++++++++++++++++++
drivers/phy/tegra/xusb-tegra210.c | 31 ++++++++++++++++++++++++++++++
drivers/phy/tegra/xusb.h | 13 +++++++++++++
3 files changed, 84 insertions(+)
Oh wait... you're not actually adding custom public APIs for this but
are simply wiring this through the SoC-specific code. Okay, that seems
fine to me.

Ignore my comments on the prior two patches.

diff --git a/drivers/phy/tegra/xusb-tegra186.c b/drivers/phy/tegra/xusb-tegra186.c
index f862254..03bdb5b 100644
--- a/drivers/phy/tegra/xusb-tegra186.c
+++ b/drivers/phy/tegra/xusb-tegra186.c
@@ -68,6 +68,13 @@
#define PORTX_SPEED_SUPPORT_MASK (0x3)
#define PORT_SPEED_SUPPORT_GEN1 (0x0)
+#define USB2_BATTERY_CHRG_OTGPADX_CTL1(x) (0x84 + (x) * 0x40)
+#define PD_VREG (1 << 6)
+#define VREG_LEV(x) (((x) & 0x3) << 7)
+#define VREG_DIR(x) (((x) & 0x3) << 11)
+#define VREG_DIR_IN VREG_DIR(1)
+#define VREG_DIR_OUT VREG_DIR(2)
+
#define XUSB_PADCTL_USB2_OTG_PADX_CTL0(x) (0x88 + (x) * 0x40)
#define HS_CURR_LEVEL(x) ((x) & 0x3f)
#define TERM_SEL BIT(25)
@@ -289,6 +296,37 @@ static void tegra_phy_xusb_utmi_pad_power_down(struct phy *phy)
usb2->powered_on = false;
}
+static void tegra186_xusb_padctl_utmi_pad_set_protection_level(
+ struct tegra_xusb_port *port, int level,
+ enum tegra_vbus_dir dir)
It's more idiomatic to wrap after the return type and while at it,
perhaps make this name a little shorter, like so:

static void
tegra186_xusb_padctl_utmi_pad_set_protection(struct tegra_xusb_port *port,
int level,
enum tegra_vbus_dir dir)

Will update accordingly.
+{
+ u32 value;
+ struct tegra_xusb_padctl *padctl = port->padctl;
+ unsigned int index = port->index;
+
+ value = padctl_readl(padctl, USB2_BATTERY_CHRG_OTGPADX_CTL1(index));
+
+ if (level < 0) {
+ /* disable pad protection */
+ value |= PD_VREG;
+ value &= ~VREG_LEV(~0);
+ value &= ~VREG_DIR(~0);
+ } else {
+ if (dir == TEGRA_VBUS_SOURCE)
+ value |= VREG_DIR_OUT;
+ else if (dir == TEGRA_VBUS_SINK)
+ value |= VREG_DIR_IN;
+
+ value &= ~PD_VREG;
+ value &= ~VREG_DIR(~0);
+ value &= ~VREG_LEV(~0);
+ value |= VREG_LEV(level);
+ }
+
+ padctl_writel(padctl, value, USB2_BATTERY_CHRG_OTGPADX_CTL1(index));
+}
+
+
There's an extra blank line above that can be dropped.

Will remove the same.
static int tegra186_xusb_padctl_vbus_override(struct tegra_xusb_padctl *padctl,
bool status)
{
@@ -935,6 +973,8 @@ static const struct tegra_xusb_padctl_ops tegra186_xusb_padctl_ops = {
.vbus_override = tegra186_xusb_padctl_vbus_override,
.utmi_pad_power_on = tegra_phy_xusb_utmi_pad_power_on,
.utmi_pad_power_down = tegra_phy_xusb_utmi_pad_power_down,
+ .utmi_pad_set_protection_level =
+ tegra186_xusb_padctl_utmi_pad_set_protection_level,
};
#if IS_ENABLED(CONFIG_ARCH_TEGRA_186_SOC)
diff --git a/drivers/phy/tegra/xusb-tegra210.c b/drivers/phy/tegra/xusb-tegra210.c
index caf0890..7d84f1a 100644
--- a/drivers/phy/tegra/xusb-tegra210.c
+++ b/drivers/phy/tegra/xusb-tegra210.c
@@ -74,6 +74,8 @@
#define XUSB_PADCTL_USB2_BATTERY_CHRG_OTGPAD_CTL1_VREG_LEV_MASK 0x3
#define XUSB_PADCTL_USB2_BATTERY_CHRG_OTGPAD_CTL1_VREG_LEV_VAL 0x1
#define XUSB_PADCTL_USB2_BATTERY_CHRG_OTGPAD_CTL1_VREG_FIX18 (1 << 6)
+#define USB2_BATTERY_CHRG_OTGPAD_CTL1_VREG_LEV(x) (((x) & 0x3) << 7)
+#define USB2_BATTERY_CHRG_OTGPAD_CTL1_VREG_DIR(x) (((x) & 0x3) << 11)
#define XUSB_PADCTL_USB2_OTG_PADX_CTL0(x) (0x088 + (x) * 0x40)
#define XUSB_PADCTL_USB2_OTG_PAD_CTL0_PD_ZI (1 << 29)
@@ -1116,6 +1118,33 @@ void tegra210_usb2_pad_power_down(struct phy *phy)
usb2->powered_on = false;
}
+static void tegra210_xusb_padctl_utmi_pad_set_protection_level(
+ struct tegra_xusb_port *port, int level,
+ enum tegra_vbus_dir dir)
Same comment as above.

will update accordingly.
+{
+ u32 value;
+ struct tegra_xusb_padctl *padctl = port->padctl;
+ unsigned int index = port->index;
+
+ value = padctl_readl(padctl,
+ XUSB_PADCTL_USB2_BATTERY_CHRG_OTGPADX_CTL1(index));
+
+ if (level < 0) {
+ /* disable pad protection */
+ value |= XUSB_PADCTL_USB2_BATTERY_CHRG_OTGPAD_CTL1_VREG_FIX18;
+ value &= USB2_BATTERY_CHRG_OTGPAD_CTL1_VREG_LEV(~0);
+ value &= ~USB2_BATTERY_CHRG_OTGPAD_CTL1_VREG_DIR(~0);
+ } else {
+ value &= ~XUSB_PADCTL_USB2_BATTERY_CHRG_OTGPAD_CTL1_VREG_FIX18;
+ value &= ~USB2_BATTERY_CHRG_OTGPAD_CTL1_VREG_DIR(~0);
+ value &= USB2_BATTERY_CHRG_OTGPAD_CTL1_VREG_LEV(~0);
+ value |= USB2_BATTERY_CHRG_OTGPAD_CTL1_VREG_LEV(level);
+ }
+
+ padctl_writel(padctl, value,
+ XUSB_PADCTL_USB2_BATTERY_CHRG_OTGPADX_CTL1(index));
+}
+
static int tegra210_usb2_phy_set_mode(struct phy *phy, enum phy_mode mode,
int submode)
{
@@ -2291,6 +2320,8 @@ static const struct tegra_xusb_padctl_ops tegra210_xusb_padctl_ops = {
.utmi_port_reset = tegra210_utmi_port_reset,
.utmi_pad_power_on = tegra210_usb2_pad_power_on,
.utmi_pad_power_down = tegra210_usb2_pad_power_down,
+ .utmi_pad_set_protection_level =
+ tegra210_xusb_padctl_utmi_pad_set_protection_level,
};
static const char * const tegra210_xusb_padctl_supply_names[] = {
diff --git a/drivers/phy/tegra/xusb.h b/drivers/phy/tegra/xusb.h
index 6995fc4..79e96b0 100644
--- a/drivers/phy/tegra/xusb.h
+++ b/drivers/phy/tegra/xusb.h
@@ -259,6 +259,17 @@ to_sata_pad(struct tegra_xusb_pad *pad)
*/
struct tegra_xusb_port_ops;
+/*
+ * Tegra OTG port VBUS direction:
+ * default (based on port capability) or
+ * as source or sink
+ */
+enum tegra_vbus_dir {
+ TEGRA_VBUS_DEFAULT,
+ TEGRA_VBUS_SOURCE,
+ TEGRA_VBUS_SINK
+};
Can't we key off of something like the OTG mode? I thought we already
carried that elsewhere.

Unlike OTG mode, this is VBUS direction, which is different and not same as mode. Hence its a seperate structure.
+
struct tegra_xusb_port {
struct tegra_xusb_padctl *padctl;
struct tegra_xusb_lane *lane;
@@ -398,6 +409,8 @@ struct tegra_xusb_padctl_ops {
int (*utmi_port_reset)(struct phy *phy);
void (*utmi_pad_power_on)(struct phy *phy);
void (*utmi_pad_power_down)(struct phy *phy);
+ void (*utmi_pad_set_protection_level)(struct tegra_xusb_port *port,
+ int max_ua, enum tegra_vbus_dir dir);
You call the variable "max_ua" here but it's "level" in the
implementations, which is slightly confusing. Please choose one and
stick with it. Also, if it's a value in microamperes, perhaps just make
it unsigned int?

Its level actually, and needed as int, as it can carry negative value. Will syncronize the naming across all places.

Thierry