[PATCH v7 4/7] usb: phy: tegra: Support OTG mode programming

Dmitry Osipenko
2021-09-12T18:19:37Z

Support programming USB PHY into OTG mode.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
drivers/usb/phy/phy-tegra-usb.c | 198 +++++++++++++++++++++++++++++-
include/linux/usb/tegra_usb_phy.h | 5 +
2 files changed, 198 insertions(+), 5 deletions(-)

diff --git a/drivers/usb/phy/phy-tegra-usb.c b/drivers/usb/phy/phy-tegra-usb.c
index c0f432d509aa..68cd4b68e3a2 100644
--- a/drivers/usb/phy/phy-tegra-usb.c
+++ b/drivers/usb/phy/phy-tegra-usb.c
@@ -63,6 +63,10 @@
#define A_VBUS_VLD_WAKEUP_EN BIT(30)

#define USB_PHY_VBUS_WAKEUP_ID 0x408
+#define ID_INT_EN BIT(0)
+#define ID_CHG_DET BIT(1)
+#define VBUS_WAKEUP_INT_EN BIT(8)
+#define VBUS_WAKEUP_CHG_DET BIT(9)
#define VBUS_WAKEUP_STS BIT(10)
#define VBUS_WAKEUP_WAKEUP_EN BIT(30)

@@ -158,6 +162,10 @@
#define USB_USBMODE_HOST (3 << 0)
#define USB_USBMODE_DEVICE (2 << 0)

+#define PMC_USB_AO 0xf0
+#define VBUS_WAKEUP_PD_P0 BIT(2)
+#define ID_PD_P0 BIT(3)
+
static DEFINE_SPINLOCK(utmip_pad_lock);
static unsigned int utmip_pad_count;

@@ -533,13 +541,14 @@ static int utmi_phy_power_on(struct tegra_usb_phy *phy)
val &= ~USB_WAKE_ON_RESUME_EN;
writel_relaxed(val, base + USB_SUSP_CTRL);

- if (phy->mode == USB_DR_MODE_PERIPHERAL) {
+ if (phy->mode != USB_DR_MODE_HOST) {
val = readl_relaxed(base + USB_SUSP_CTRL);
val &= ~(USB_WAKE_ON_CNNT_EN_DEV | USB_WAKE_ON_DISCON_EN_DEV);
writel_relaxed(val, base + USB_SUSP_CTRL);

val = readl_relaxed(base + USB_PHY_VBUS_WAKEUP_ID);
val &= ~VBUS_WAKEUP_WAKEUP_EN;
+ val &= ~(ID_CHG_DET | VBUS_WAKEUP_CHG_DET);
writel_relaxed(val, base + USB_PHY_VBUS_WAKEUP_ID);

val = readl_relaxed(base + USB_PHY_VBUS_SENSORS);
@@ -687,9 +696,10 @@ static int utmi_phy_power_off(struct tegra_usb_phy *phy)
* Ask VBUS sensor to generate wake event once cable is
* connected.
*/
- if (phy->mode == USB_DR_MODE_PERIPHERAL) {
+ if (phy->mode != USB_DR_MODE_HOST) {
val = readl_relaxed(base + USB_PHY_VBUS_WAKEUP_ID);
val |= VBUS_WAKEUP_WAKEUP_EN;
+ val &= ~(ID_CHG_DET | VBUS_WAKEUP_CHG_DET);
writel_relaxed(val, base + USB_PHY_VBUS_WAKEUP_ID);

val = readl_relaxed(base + USB_PHY_VBUS_SENSORS);
@@ -893,6 +903,7 @@ static void tegra_usb_phy_shutdown(struct usb_phy *u_phy)
if (WARN_ON(!phy->freq))
return;

+ usb_phy_set_wakeup(u_phy, false);
tegra_usb_phy_power_off(phy);

if (!phy->is_ulpi_phy)
@@ -904,26 +915,146 @@ static void tegra_usb_phy_shutdown(struct usb_phy *u_phy)
phy->freq = NULL;
}

+static irqreturn_t tegra_usb_phy_isr(int irq, void *data)
+{
+ u32 val, int_mask = ID_CHG_DET | VBUS_WAKEUP_CHG_DET;
+ struct tegra_usb_phy *phy = data;
+ void __iomem *base = phy->regs;
+
+ /*
+ * The PHY interrupt also wakes the USB controller driver since
+ * interrupt is shared. We don't do anything in the PHY driver,
+ * so just clear the interrupt.
+ */
+ val = readl_relaxed(base + USB_PHY_VBUS_WAKEUP_ID);
+ writel_relaxed(val, base + USB_PHY_VBUS_WAKEUP_ID);
+
+ return val & int_mask ? IRQ_HANDLED : IRQ_NONE;
+}
+
static int tegra_usb_phy_set_wakeup(struct usb_phy *u_phy, bool enable)
{
struct tegra_usb_phy *phy = to_tegra_usb_phy(u_phy);
+ void __iomem *base = phy->regs;
+ int ret = 0;
+ u32 val;
+
+ if (phy->wakeup_enabled && phy->mode != USB_DR_MODE_HOST &&
+ phy->irq > 0) {
+ disable_irq(phy->irq);
+
+ val = readl_relaxed(base + USB_PHY_VBUS_WAKEUP_ID);
+ val &= ~(ID_INT_EN | VBUS_WAKEUP_INT_EN);
+ writel_relaxed(val, base + USB_PHY_VBUS_WAKEUP_ID);
+
+ enable_irq(phy->irq);
+
+ free_irq(phy->irq, phy);
+
+ phy->wakeup_enabled = false;
+ }
+
+ if (enable && phy->mode != USB_DR_MODE_HOST && phy->irq > 0) {
+ ret = request_irq(phy->irq, tegra_usb_phy_isr, IRQF_SHARED,
+ dev_name(phy->u_phy.dev), phy);
+ if (!ret) {
+ disable_irq(phy->irq);
+
+ /*
+ * USB clock will be resumed once wake event will be
+ * generated. The ID-change event requires to have
+ * interrupts enabled, otherwise it won't be generated.
+ */
+ val = readl_relaxed(base + USB_PHY_VBUS_WAKEUP_ID);
+ val |= ID_INT_EN | VBUS_WAKEUP_INT_EN;
+ writel_relaxed(val, base + USB_PHY_VBUS_WAKEUP_ID);
+
+ enable_irq(phy->irq);
+ } else {
+ dev_err(phy->u_phy.dev,
+ "Failed to request interrupt: %d", ret);
+ enable = false;
+ }
+ }

phy->wakeup_enabled = enable;

- return 0;
+ return ret;
}

static int tegra_usb_phy_set_suspend(struct usb_phy *u_phy, int suspend)
{
struct tegra_usb_phy *phy = to_tegra_usb_phy(u_phy);
+ int ret;

if (WARN_ON(!phy->freq))
return -EINVAL;

+ /*
+ * PHY is sharing IRQ with the CI driver, hence here we either
+ * disable interrupt for both PHY and CI or for CI only. The
+ * interrupt needs to be disabled while hardware is reprogrammed
+ * because interrupt touches the programmed registers, and thus,
+ * there could be a race condition.
+ */
+ if (phy->irq > 0)
+ disable_irq(phy->irq);
+
if (suspend)
- return tegra_usb_phy_power_off(phy);
+ ret = tegra_usb_phy_power_off(phy);
else
- return tegra_usb_phy_power_on(phy);
+ ret = tegra_usb_phy_power_on(phy);
+
+ if (phy->irq > 0)
+ enable_irq(phy->irq);
+
+ return ret;
+}
+
+static int tegra_usb_phy_configure_pmc(struct tegra_usb_phy *phy)
+{
+ int err, val = 0;
+
+ /* older device-trees don't have PMC regmap */
+ if (!phy->pmc_regmap)
+ return 0;
+
+ /*
+ * Tegra20 has a different layout of PMC USB register bits and AO is
+ * enabled by default after system reset on Tegra20, so assume nothing
+ * to do on Tegra20.
+ */
+ if (!phy->soc_config->requires_pmc_ao_power_up)
+ return 0;
+
+ /* enable VBUS wake-up detector */
+ if (phy->mode != USB_DR_MODE_HOST)
+ val |= VBUS_WAKEUP_PD_P0 << phy->instance * 4;
+
+ /* enable ID-pin ACC detector for OTG mode switching */
+ if (phy->mode == USB_DR_MODE_OTG)
+ val |= ID_PD_P0 << phy->instance * 4;
+
+ /* disable detectors to reset them */
+ err = regmap_set_bits(phy->pmc_regmap, PMC_USB_AO, val);
+ if (err) {
+ dev_err(phy->u_phy.dev, "Failed to disable PMC AO: %d\n", err);
+ return err;
+ }
+
+ usleep_range(10, 100);
+
+ /* enable detectors */
+ err = regmap_clear_bits(phy->pmc_regmap, PMC_USB_AO, val);
+ if (err) {
+ dev_err(phy->u_phy.dev, "Failed to enable PMC AO: %d\n", err);
+ return err;
+ }
+
+ /* detectors starts to work after 10ms */
+ usleep_range(10000, 15000);
+
+ return 0;
}

static int tegra_usb_phy_init(struct usb_phy *u_phy)
@@ -967,6 +1098,10 @@ static int tegra_usb_phy_init(struct usb_phy *u_phy)
goto disable_vbus;
}

+ err = tegra_usb_phy_configure_pmc(phy);
+ if (err)
+ goto close_phy;
+
err = tegra_usb_phy_power_on(phy);
if (err)
goto close_phy;
@@ -1135,11 +1270,56 @@ static int utmi_phy_probe(struct tegra_usb_phy *tegra_phy,
return 0;
}

+static void tegra_usb_phy_put_pmc_device(void *dev)
+{
+ put_device(dev);
+}
+
+static int tegra_usb_phy_parse_pmc(struct device *dev,
+ struct tegra_usb_phy *phy)
+{
+ struct platform_device *pmc_pdev;
+ struct of_phandle_args args;
+ int err;
+
+ err = of_parse_phandle_with_fixed_args(dev->of_node, "nvidia,pmc",
+ 1, 0, &args);
+ if (err) {
+ if (err != -ENOENT)
+ return err;
+
+ dev_warn_once(dev, "nvidia,pmc is missing, please update your device-tree\n");
+ return 0;
+ }
+
+ pmc_pdev = of_find_device_by_node(args.np);
+ of_node_put(args.np);
+ if (!pmc_pdev)
+ return -ENODEV;
+
+ err = devm_add_action_or_reset(dev, tegra_usb_phy_put_pmc_device,
+ &pmc_pdev->dev);
+ if (err)
+ return err;
+
+ if (!platform_get_drvdata(pmc_pdev))
+ return -EPROBE_DEFER;
+
+ phy->pmc_regmap = dev_get_regmap(&pmc_pdev->dev, "usb_sleepwalk");
+ if (!phy->pmc_regmap)
+ return -EINVAL;
+
+ phy->instance = args.args[0];
+
+ return 0;
+}
+
static const struct tegra_phy_soc_config tegra20_soc_config = {
.utmi_pll_config_in_car_module = false,
.has_hostpc = false,
.requires_usbmode_setup = false,
.requires_extra_tuning_parameters = false,
+ .requires_pmc_ao_power_up = false,
};

static const struct tegra_phy_soc_config tegra30_soc_config = {
@@ -1147,6 +1327,7 @@ static const struct tegra_phy_soc_config tegra30_soc_config = {
.has_hostpc = true,
.requires_usbmode_setup = true,
.requires_extra_tuning_parameters = true,
+ .requires_pmc_ao_power_up = true,
};

static const struct of_device_id tegra_usb_phy_id_table[] = {
@@ -1172,6 +1353,7 @@ static int tegra_usb_phy_probe(struct platform_device *pdev)
return -ENOMEM;

tegra_phy->soc_config = of_device_get_match_data(&pdev->dev);
+ tegra_phy->irq = platform_get_irq_optional(pdev, 0);

res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
@@ -1215,6 +1397,12 @@ static int tegra_usb_phy_probe(struct platform_device *pdev)
return err;
}

+ err = tegra_usb_phy_parse_pmc(&pdev->dev, tegra_phy);
+ if (err) {
+ dev_err_probe(&pdev->dev, err, "Failed to get PMC regmap\n");
+ return err;
+ }
+
phy_type = of_usb_get_phy_mode(np);
switch (phy_type) {
case USBPHY_INTERFACE_MODE_UTMI:
diff --git a/include/linux/usb/tegra_usb_phy.h b/include/linux/usb/tegra_usb_phy.h
index fd1c9f6a4e37..d3e65eb9e16f 100644
--- a/include/linux/usb/tegra_usb_phy.h
+++ b/include/linux/usb/tegra_usb_phy.h
@@ -18,6 +18,7 @@

#include <linux/clk.h>
#include <linux/gpio.h>
+#include <linux/regmap.h>
#include <linux/reset.h>
#include <linux/usb/otg.h>

@@ -30,6 +31,7 @@
* enter host mode
* requires_extra_tuning_parameters: true if xcvr_hsslew, hssquelch_level
* and hsdiscon_level should be set for adequate signal quality
+ * requires_pmc_ao_power_up: true if USB AO is powered down by default
*/

struct tegra_phy_soc_config {
@@ -37,6 +39,7 @@ struct tegra_phy_soc_config {
bool has_hostpc;
bool requires_usbmode_setup;
bool requires_extra_tuning_parameters;
+ bool requires_pmc_ao_power_up;
};

struct tegra_utmip_config {
@@ -62,6 +65,7 @@ enum tegra_usb_phy_port_speed {
struct tegra_xtal_freq;

struct tegra_usb_phy {
+ int irq;
int instance;
const struct tegra_xtal_freq *freq;
void __iomem *regs;
@@ -70,6 +74,7 @@ struct tegra_usb_phy {
struct clk *pll_u;
struct clk *pad_clk;
struct regulator *vbus;
+ struct regmap *pmc_regmap;
enum usb_dr_mode mode;
void *config;
const struct tegra_phy_soc_config *soc_config;
--
2.32.0