usb: phy: tegra: Support OTG mode programming
authorDmitry Osipenko <digetx@gmail.com>
Sun, 12 Sep 2021 18:17:15 +0000 (21:17 +0300)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tue, 5 Oct 2021 10:47:49 +0000 (12:47 +0200)
Support programming USB PHY into OTG mode.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20210912181718.1328-5-digetx@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/phy/phy-tegra-usb.c
include/linux/usb/tegra_usb_phy.h

index c0f432d509aab3578c54812639b889a8ccfcba27..68cd4b68e3a207f66a7a2fbdd9d6295cc4210111 100644 (file)
 #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)
 
 #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:
index fd1c9f6a4e37f4d3881e2b059ba81d52f8d4e35d..d3e65eb9e16f7efc7602b32de75982b603911022 100644 (file)
@@ -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;