usb: dwc2: gadget: add TEST_MODE feature support

Handle SET_FEATURE TEST_MODE request sent by the host.
Slightly rework FEATURE request handling to allow parsing
other request types than Endpoint.
Also add a debugfs to change test mode value from user space.

Tested-by: Robert Baldyga <r.baldyga@samsung.com>
Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Gregory Herrero <gregory.herrero@intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

2 files changed, 186 insertions, 7 deletions

diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h
index f09b3deffdee..c750fd3d88b3 100644
--- a/drivers/usb/dwc2/core.h
+++ b/drivers/usb/dwc2/core.h
@@ -567,12 +567,14 @@ struct dwc2_hw_params {
  * @num_of_eps:         Number of available EPs (excluding EP0)
  * @debug_root:         Root directrory for debugfs.
  * @debug_file:         Main status file for debugfs.
+ * @debug_testmode:     Testmode status file for debugfs.
  * @debug_fifo:         FIFO status file for debugfs.
  * @ep0_reply:          Request used for ep0 reply.
  * @ep0_buff:           Buffer for EP0 reply data, if needed.
  * @ctrl_buff:          Buffer for EP0 control requests.
  * @ctrl_req:           Request for EP0 control packets.
  * @ep0_state:          EP0 control transfers state
+ * @test_mode:          USB test mode requested by the host
  * @last_rst:           Time of last reset
  * @eps:                The endpoints being supplied to the gadget framework
  * @g_using_dma:          Indicate if dma usage is enabled
@@ -610,6 +612,7 @@ struct dwc2_hsotg {
 
         struct dentry *debug_root;
         struct dentry *debug_file;
+        struct dentry *debug_testmode;
         struct dentry *debug_fifo;
 
         /* DWC OTG HW Release versions */
@@ -706,6 +709,7 @@ struct dwc2_hsotg {
         void *ep0_buff;
         void *ctrl_buff;
         enum dwc2_ep0_state ep0_state;
+        u8 test_mode;
 
         struct usb_gadget gadget;
         unsigned int enabled:1;
diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
index 02d0e9af9242..67ea258335ad 100644
--- a/drivers/usb/dwc2/gadget.c
+++ b/drivers/usb/dwc2/gadget.c
@@ -35,6 +35,7 @@
 #include <linux/usb/gadget.h>
 #include <linux/usb/phy.h>
 #include <linux/platform_data/s3c-hsotg.h>
+#include <linux/uaccess.h>
 
 #include "core.h"
 #include "hw.h"
@@ -835,6 +836,32 @@ static struct s3c_hsotg_ep *ep_from_windex(struct dwc2_hsotg *hsotg,
 }
 
 /**
+ * s3c_hsotg_set_test_mode - Enable usb Test Modes
+ * @hsotg: The driver state.
+ * @testmode: requested usb test mode
+ * Enable usb Test Mode requested by the Host.
+ */
+static int s3c_hsotg_set_test_mode(struct dwc2_hsotg *hsotg, int testmode)
+{
+        int dctl = readl(hsotg->regs + DCTL);
+
+        dctl &= ~DCTL_TSTCTL_MASK;
+        switch (testmode) {
+        case TEST_J:
+        case TEST_K:
+        case TEST_SE0_NAK:
+        case TEST_PACKET:
+        case TEST_FORCE_EN:
+                dctl |= testmode << DCTL_TSTCTL_SHIFT;
+                break;
+        default:
+                return -EINVAL;
+        }
+        writel(dctl, hsotg->regs + DCTL);
+        return 0;
+}
+
+/**
  * s3c_hsotg_send_reply - send reply to control request
  * @hsotg: The device state
  * @ep: Endpoint 0
@@ -968,19 +995,48 @@ static int s3c_hsotg_process_req_feature(struct dwc2_hsotg *hsotg,
         struct s3c_hsotg_ep *ep;
         int ret;
         bool halted;
+        u32 recip;
+        u32 wValue;
+        u32 wIndex;
 
         dev_dbg(hsotg->dev, "%s: %s_FEATURE\n",
                 __func__, set ? "SET" : "CLEAR");
 
-        if (ctrl->bRequestType == USB_RECIP_ENDPOINT) {
-                ep = ep_from_windex(hsotg, le16_to_cpu(ctrl->wIndex));
+        wValue = le16_to_cpu(ctrl->wValue);
+        wIndex = le16_to_cpu(ctrl->wIndex);
+        recip = ctrl->bRequestType & USB_RECIP_MASK;
+
+        switch (recip) {
+        case USB_RECIP_DEVICE:
+                switch (wValue) {
+                case USB_DEVICE_TEST_MODE:
+                        if ((wIndex & 0xff) != 0)
+                                return -EINVAL;
+                        if (!set)
+                                return -EINVAL;
+
+                        hsotg->test_mode = wIndex >> 8;
+                        ret = s3c_hsotg_send_reply(hsotg, ep0, NULL, 0);
+                        if (ret) {
+                                dev_err(hsotg->dev,
+                                        "%s: failed to send reply\n", __func__);
+                                return ret;
+                        }
+                        break;
+                default:
+                        return -ENOENT;
+                }
+                break;
+
+        case USB_RECIP_ENDPOINT:
+                ep = ep_from_windex(hsotg, wIndex);
                 if (!ep) {
                         dev_dbg(hsotg->dev, "%s: no endpoint for 0x%04x\n",
-                                __func__, le16_to_cpu(ctrl->wIndex));
+                                __func__, wIndex);
                         return -ENOENT;
                 }
 
-                switch (le16_to_cpu(ctrl->wValue)) {
+                switch (wValue) {
                 case USB_ENDPOINT_HALT:
                         halted = ep->halted;
 
@@ -1031,9 +1087,10 @@ static int s3c_hsotg_process_req_feature(struct dwc2_hsotg *hsotg,
                 default:
                         return -ENOENT;
                 }
-        } else
-                return -ENOENT;  /* currently only deal with endpoint */
-
+                break;
+        default:
+                return -ENOENT;
+        }
         return 1;
 }
 
@@ -1734,6 +1791,17 @@ static void s3c_hsotg_complete_in(struct dwc2_hsotg *hsotg,
         if (hs_ep->index == 0 && hsotg->ep0_state == DWC2_EP0_STATUS_IN) {
                 dev_dbg(hsotg->dev, "zlp packet sent\n");
                 s3c_hsotg_complete_request(hsotg, hs_ep, hs_req, 0);
+                if (hsotg->test_mode) {
+                        int ret;
+
+                        ret = s3c_hsotg_set_test_mode(hsotg, hsotg->test_mode);
+                        if (ret < 0) {
+                                dev_dbg(hsotg->dev, "Invalid Test #%d\n",
+                                                hsotg->test_mode);
+                                s3c_hsotg_stall_ep0(hsotg);
+                                return;
+                        }
+                }
                 s3c_hsotg_enqueue_setup(hsotg);
                 return;
         }
@@ -2045,6 +2113,7 @@ void s3c_hsotg_disconnect(struct dwc2_hsotg *hsotg)
                 return;
 
         hsotg->connected = 0;
+        hsotg->test_mode = 0;
 
         for (ep = 0; ep < hsotg->num_of_eps; ep++) {
                 if (hsotg->eps_in[ep])
@@ -3257,6 +3326,103 @@ static void s3c_hsotg_dump(struct dwc2_hsotg *hsotg)
 }
 
 /**
+ * testmode_write - debugfs: change usb test mode
+ * @seq: The seq file to write to.
+ * @v: Unused parameter.
+ *
+ * This debugfs entry modify the current usb test mode.
+ */
+static ssize_t testmode_write(struct file *file, const char __user *ubuf, size_t
+                count, loff_t *ppos)
+{
+        struct seq_file         *s = file->private_data;
+        struct dwc2_hsotg       *hsotg = s->private;
+        unsigned long           flags;
+        u32                     testmode = 0;
+        char                    buf[32];
+
+        if (copy_from_user(&buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
+                return -EFAULT;
+
+        if (!strncmp(buf, "test_j", 6))
+                testmode = TEST_J;
+        else if (!strncmp(buf, "test_k", 6))
+                testmode = TEST_K;
+        else if (!strncmp(buf, "test_se0_nak", 12))
+                testmode = TEST_SE0_NAK;
+        else if (!strncmp(buf, "test_packet", 11))
+                testmode = TEST_PACKET;
+        else if (!strncmp(buf, "test_force_enable", 17))
+                testmode = TEST_FORCE_EN;
+        else
+                testmode = 0;
+
+        spin_lock_irqsave(&hsotg->lock, flags);
+        s3c_hsotg_set_test_mode(hsotg, testmode);
+        spin_unlock_irqrestore(&hsotg->lock, flags);
+        return count;
+}
+
+/**
+ * testmode_show - debugfs: show usb test mode state
+ * @seq: The seq file to write to.
+ * @v: Unused parameter.
+ *
+ * This debugfs entry shows which usb test mode is currently enabled.
+ */
+static int testmode_show(struct seq_file *s, void *unused)
+{
+        struct dwc2_hsotg *hsotg = s->private;
+        unsigned long flags;
+        int dctl;
+
+        spin_lock_irqsave(&hsotg->lock, flags);
+        dctl = readl(hsotg->regs + DCTL);
+        dctl &= DCTL_TSTCTL_MASK;
+        dctl >>= DCTL_TSTCTL_SHIFT;
+        spin_unlock_irqrestore(&hsotg->lock, flags);
+
+        switch (dctl) {
+        case 0:
+                seq_puts(s, "no test\n");
+                break;
+        case TEST_J:
+                seq_puts(s, "test_j\n");
+                break;
+        case TEST_K:
+                seq_puts(s, "test_k\n");
+                break;
+        case TEST_SE0_NAK:
+                seq_puts(s, "test_se0_nak\n");
+                break;
+        case TEST_PACKET:
+                seq_puts(s, "test_packet\n");
+                break;
+        case TEST_FORCE_EN:
+                seq_puts(s, "test_force_enable\n");
+                break;
+        default:
+                seq_printf(s, "UNKNOWN %d\n", dctl);
+        }
+
+        return 0;
+}
+
+static int testmode_open(struct inode *inode, struct file *file)
+{
+        return single_open(file, testmode_show, inode->i_private);
+}
+
+static const struct file_operations testmode_fops = {
+        .owner          = THIS_MODULE,
+        .open           = testmode_open,
+        .write          = testmode_write,
+        .read           = seq_read,
+        .llseek         = seq_lseek,
+        .release        = single_release,
+};
+
+/**
  * state_show - debugfs: show overall driver and device state.
  * @seq: The seq file to write to.
  * @v: Unused parameter.
@@ -3490,6 +3656,14 @@ static void s3c_hsotg_create_debug(struct dwc2_hsotg *hsotg)
         if (IS_ERR(hsotg->debug_file))
                 dev_err(hsotg->dev, "%s: failed to create state\n", __func__);
 
+        hsotg->debug_testmode = debugfs_create_file("testmode",
+                                        S_IRUGO | S_IWUSR, root,
+                                        hsotg, &testmode_fops);
+
+        if (IS_ERR(hsotg->debug_testmode))
+                dev_err(hsotg->dev, "%s: failed to create testmode\n",
+                                __func__);
+
         hsotg->debug_fifo = debugfs_create_file("fifo", 0444, root,
                                                 hsotg, &fifo_fops);
 
@@ -3544,6 +3718,7 @@ static void s3c_hsotg_delete_debug(struct dwc2_hsotg *hsotg)
         }
 
         debugfs_remove(hsotg->debug_file);
+        debugfs_remove(hsotg->debug_testmode);
         debugfs_remove(hsotg->debug_fifo);
         debugfs_remove(hsotg->debug_root);
 }