dwc3: exynos: add software role switching code

Exynos platform doesn't have hardware OTG support, so we need to
supply mechanism of notification about cable change.

Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>

diff --git a/drivers/usb/dwc3/dwc3-exynos.c b/drivers/usb/dwc3/dwc3-exynos.c
index 7bd0a95..30a0560 100644 (file)
--- a/drivers/usb/dwc3/dwc3-exynos.c
+++ b/drivers/usb/dwc3/dwc3-exynos.c
@@ -27,6 +27,10 @@
 #include <linux/of.h>
 #include <linux/of_platform.h>
 #include <linux/regulator/consumer.h>
+#include <linux/extcon.h>
+#include <linux/workqueue.h>
+
+#include "otg.h"
 
 struct dwc3_exynos {
        struct platform_device  *usb2_phy;
@@ -39,8 +43,107 @@ struct dwc3_exynos {
 
        struct regulator        *vdd33;
        struct regulator        *vdd10;
+
+       struct otg_fsm          *fsm;
+
+       struct extcon_dev       *extcon;
+       struct extcon_specific_cable_nb extcon_usb_dev;
+       struct extcon_specific_cable_nb extcon_usb_host_dev;
+       struct notifier_block   usb_nb;
+       struct notifier_block   usb_host_nb;
+       struct work_struct      work;
 };
 
+static int dwc3_exynos_usb_notifier(struct notifier_block *nb,
+               unsigned long event, void *ptr);
+
+static int dwc3_exynos_usb_host_notifier(struct notifier_block *nb,
+               unsigned long event, void *ptr);
+
+int dwc3_exynos_rsw_start(struct device *dev)
+{
+       struct dwc3_exynos *exynos = dev_get_drvdata(dev);
+       int ret;
+
+       dev_dbg(dev, "%s\n", __func__);
+
+       if (!exynos->extcon)
+               return -ENODEV;
+
+       exynos->usb_nb.notifier_call = dwc3_exynos_usb_notifier;
+       exynos->usb_host_nb.notifier_call = dwc3_exynos_usb_host_notifier;
+
+       ret = extcon_register_interest(&exynos->extcon_usb_dev,
+                       exynos->extcon->name, "USB", &exynos->usb_nb);
+       if (ret < 0) {
+               dev_dbg(dev, "failed to register notifier for USB");
+               return -ENODEV;
+       }
+
+       ret = extcon_register_interest(&exynos->extcon_usb_host_dev,
+                       exynos->extcon->name, "USB-HOST", &exynos->usb_host_nb);
+       if (ret < 0) {
+               dev_dbg(dev, "failed to register notifier for USB HOST");
+               extcon_unregister_interest(&exynos->extcon_usb_dev);
+               return -ENODEV;
+       }
+
+       if (extcon_get_cable_state(exynos->extcon, "USB")) {
+               exynos->fsm->b_sess_vld = 1;
+               exynos->fsm->id = 1;
+       } else if (extcon_get_cable_state(exynos->extcon, "USB-HOST")) {
+               exynos->fsm->b_sess_vld = 0;
+               exynos->fsm->id = 0;
+       } else {
+               exynos->fsm->b_sess_vld = 0;
+               exynos->fsm->id = 1;
+       }
+
+       dwc3_otg_run_sm(exynos->fsm);
+
+       return 0;
+}
+
+void dwc3_exynos_rsw_stop(struct device *dev)
+{
+       struct dwc3_exynos *exynos = dev_get_drvdata(dev);
+
+       dev_dbg(dev, "%s\n", __func__);
+
+       if (exynos->extcon_usb_dev.edev)
+               extcon_unregister_interest(&exynos->extcon_usb_dev);
+       if (exynos->extcon_usb_host_dev.edev)
+               extcon_unregister_interest(&exynos->extcon_usb_host_dev);
+}
+
+int dwc3_exynos_rsw_setup(struct device *dev, struct otg_fsm *fsm)
+{
+       struct dwc3_exynos *exynos = dev_get_drvdata(dev);
+
+       dev_dbg(dev, "%s\n", __func__);
+
+       exynos->fsm = fsm;
+
+       return 0;
+}
+
+void dwc3_exynos_rsw_exit(struct device *dev)
+{
+       struct dwc3_exynos      *exynos = dev_get_drvdata(dev);
+
+       dev_dbg(dev, "%s\n", __func__);
+
+       exynos->fsm = NULL;
+}
+
+bool dwc3_exynos_rsw_available(struct device *dev)
+{
+       if (of_property_read_bool(dev->of_node, "extcon"))
+               return true;
+
+       return false;
+}
+
 static int dwc3_exynos_register_phys(struct dwc3_exynos *exynos)
 {
        struct usb_phy_generic_platform_data pdata;
@@ -105,18 +208,77 @@ static int dwc3_exynos_remove_child(struct device *dev, void *unused)
        return 0;
 }
 
+static void dwc3_exynos_worker(struct work_struct *work)
+{
+       struct dwc3_exynos *exynos =
+               container_of(work, struct dwc3_exynos, work);
+
+       dwc3_otg_run_sm(exynos->fsm);
+}
+
+static int dwc3_exynos_usb_notifier(struct notifier_block *nb,
+               unsigned long event, void *ptr)
+{
+       struct dwc3_exynos *exynos =
+               container_of(nb, struct dwc3_exynos, usb_nb);
+
+       if (event) {
+               exynos->fsm->b_sess_vld = 1;
+               exynos->fsm->id = 1;
+       } else {
+               exynos->fsm->b_sess_vld = 0;
+               exynos->fsm->id = 1;
+       }
+
+       schedule_work(&exynos->work);
+
+       return 0;
+}
+
+static int dwc3_exynos_usb_host_notifier(struct notifier_block *nb,
+               unsigned long event, void *ptr)
+{
+       struct dwc3_exynos *exynos =
+               container_of(nb, struct dwc3_exynos, usb_host_nb);
+
+       if (event) {
+               exynos->fsm->b_sess_vld = 0;
+               exynos->fsm->id = 0;
+       } else {
+               exynos->fsm->b_sess_vld = 0;
+               exynos->fsm->id = 1;
+       }
+
+       schedule_work(&exynos->work);
+
+       return 0;
+}
+
 static int dwc3_exynos_probe(struct platform_device *pdev)
 {
        struct dwc3_exynos      *exynos;
        struct device           *dev = &pdev->dev;
        struct device_node      *node = dev->of_node;
+       struct extcon_dev       *extcon = NULL;
 
        int                     ret;
 
+       if (of_property_read_bool(node, "extcon")) {
+               extcon = extcon_get_edev_by_phandle(dev, 0);
+               if (IS_ERR(extcon)) {
+                       dev_vdbg(dev, "couldn't get extcon device\n");
+                       return -EPROBE_DEFER;
+               }
+       }
+
        exynos = devm_kzalloc(dev, sizeof(*exynos), GFP_KERNEL);
        if (!exynos)
                return -ENOMEM;
 
+       exynos->extcon = extcon;
+
+       INIT_WORK(&exynos->work, dwc3_exynos_worker);
+
        /*
         * Right now device-tree probed devices don't get dma_mask set.
         * Since shared usb code relies on it, set it here for now.

diff --git a/drivers/usb/dwc3/otg.c b/drivers/usb/dwc3/otg.c
index 56bc6b6..9c0da03 100644 (file)
--- a/drivers/usb/dwc3/otg.c
+++ b/drivers/usb/dwc3/otg.c
@@ -28,10 +28,37 @@
 #include "otg.h"
 #include "io.h"
 
+#if IS_ENABLED(CONFIG_USB_DWC3_EXYNOS)
+static struct dwc3_ext_otg_ops *dwc3_otg_rsw_probe(struct dwc3 *dwc)
+{
+       struct dwc3_ext_otg_ops *ops;
+       bool                    ext_otg;
+
+       ext_otg = dwc3_exynos_rsw_available(dwc->dev->parent);
+       if (!ext_otg)
+               return NULL;
+
+       /* Allocate and init otg instance */
+       ops = devm_kzalloc(dwc->dev, sizeof(struct dwc3_ext_otg_ops),
+                       GFP_KERNEL);
+       if (!ops) {
+               dev_err(dwc->dev, "unable to allocate dwc3_ext_otg_ops\n");
+               return NULL;
+       }
+
+       ops->setup = dwc3_exynos_rsw_setup;
+       ops->exit = dwc3_exynos_rsw_exit;
+       ops->start = dwc3_exynos_rsw_start;
+       ops->stop = dwc3_exynos_rsw_stop;
+
+       return ops;
+}
+#else
 static struct dwc3_ext_otg_ops *dwc3_otg_rsw_probe(struct dwc3 *dwc)
 {
        return NULL;
 }
+#endif
 
 static int dwc3_otg_statemachine(struct otg_fsm *fsm, bool reset)
 {

diff --git a/drivers/usb/dwc3/otg.h b/drivers/usb/dwc3/otg.h
index 25bc027..024b885 100644 (file)
--- a/drivers/usb/dwc3/otg.h
+++ b/drivers/usb/dwc3/otg.h
@@ -96,4 +96,13 @@ static inline int dwc3_ext_otg_stop(struct dwc3_otg *dotg)
 
 void dwc3_otg_run_sm(struct otg_fsm *fsm);
 
+/* prototypes */
+#if IS_ENABLED(CONFIG_USB_DWC3_EXYNOS)
+bool dwc3_exynos_rsw_available(struct device *dev);
+int dwc3_exynos_rsw_setup(struct device *dev, struct otg_fsm *fsm);
+void dwc3_exynos_rsw_exit(struct device *dev);
+int dwc3_exynos_rsw_start(struct device *dev);
+void dwc3_exynos_rsw_stop(struct device *dev);
+#endif
+
 #endif /* __LINUX_USB_DWC3_OTG_H */