usb: dwc3: calculate number of event buffers dynamically

This will allow us to only allocate memory when
we actually need.

Signed-off-by: Felipe Balbi <balbi@ti.com>

3 files changed, 18 insertions, 13 deletions

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index ca3b01f5fffa..1f67606fd4fb 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -154,7 +154,7 @@ static void dwc3_free_event_buffers(struct dwc3 *dwc)
         struct dwc3_event_buffer        *evt;
         int i;
 
-        for (i = 0; i < DWC3_EVENT_BUFFERS_NUM; i++) {
+        for (i = 0; i < dwc->num_event_buffers; i++) {
                 evt = dwc->ev_buffs[i];
                 if (evt) {
                         dwc3_free_one_event_buffer(dwc, evt);
@@ -166,17 +166,19 @@ static void dwc3_free_event_buffers(struct dwc3 *dwc)
 /**
  * dwc3_alloc_event_buffers - Allocates @num event buffers of size @length
  * @dwc: Pointer to out controller context structure
- * @num: number of event buffers to allocate
  * @length: size of event buffer
  *
  * Returns 0 on success otherwise negative errno. In error the case, dwc
  * may contain some buffers allocated but not all which were requested.
  */
-static int __devinit dwc3_alloc_event_buffers(struct dwc3 *dwc, unsigned num,
-                unsigned length)
+static int __devinit dwc3_alloc_event_buffers(struct dwc3 *dwc, unsigned length)
 {
+        int                     num;
         int                     i;
 
+        num = DWC3_NUM_INT(dwc->hwparams.hwparams1);
+        dwc->num_event_buffers = num;
+
         for (i = 0; i < num; i++) {
                 struct dwc3_event_buffer        *evt;
 
@@ -202,7 +204,7 @@ static int __devinit dwc3_event_buffers_setup(struct dwc3 *dwc)
         struct dwc3_event_buffer        *evt;
         int                             n;
 
-        for (n = 0; n < DWC3_EVENT_BUFFERS_NUM; n++) {
+        for (n = 0; n < dwc->num_event_buffers; n++) {
                 evt = dwc->ev_buffs[n];
                 dev_dbg(dwc->dev, "Event buf %p dma %08llx length %d\n",
                                 evt->buf, (unsigned long long) evt->dma,
@@ -225,7 +227,7 @@ static void dwc3_event_buffers_cleanup(struct dwc3 *dwc)
         struct dwc3_event_buffer        *evt;
         int                             n;
 
-        for (n = 0; n < DWC3_EVENT_BUFFERS_NUM; n++) {
+        for (n = 0; n < dwc->num_event_buffers; n++) {
                 evt = dwc->ev_buffs[n];
                 dwc3_writel(dwc->regs, DWC3_GEVNTADRLO(n), 0);
                 dwc3_writel(dwc->regs, DWC3_GEVNTADRHI(n), 0);
@@ -289,8 +291,9 @@ static int __devinit dwc3_core_init(struct dwc3 *dwc)
                 cpu_relax();
         } while (true);
 
-        ret = dwc3_alloc_event_buffers(dwc, DWC3_EVENT_BUFFERS_NUM,
-                        DWC3_EVENT_BUFFERS_SIZE);
+        dwc3_cache_hwparams(dwc);
+
+        ret = dwc3_alloc_event_buffers(dwc, DWC3_EVENT_BUFFERS_SIZE);
         if (ret) {
                 dev_err(dwc->dev, "failed to allocate event buffers\n");
                 ret = -ENOMEM;
@@ -303,8 +306,6 @@ static int __devinit dwc3_core_init(struct dwc3 *dwc)
                 goto err1;
         }
 
-        dwc3_cache_hwparams(dwc);
-
         return 0;
 
 err1:
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index b7d56c3a1fbb..4b6c673ed608 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -52,7 +52,7 @@
 /* Global constants */
 #define DWC3_ENDPOINTS_NUM      32
 
-#define DWC3_EVENT_BUFFERS_NUM  2
+#define DWC3_EVENT_BUFFERS_MAX  2
 #define DWC3_EVENT_BUFFERS_SIZE PAGE_SIZE
 #define DWC3_EVENT_TYPE_MASK    0xfe
 
@@ -536,6 +536,8 @@ struct dwc3_hwparams {
         u32     hwparams8;
 };
 
+#define DWC3_NUM_INT(n) (((n) & (0x3f << 15)) >> 15)
+
 /**
  * struct dwc3 - representation of our controller
  * @ctrl_req: usb control request which is used for ep0
@@ -555,6 +557,7 @@ struct dwc3_hwparams {
  * @regs: base address for our registers
  * @regs_size: address space size
  * @irq: IRQ number
+ * @num_event_buffers: calculated number of event buffers
  * @maximum_speed: maximum speed requested (mainly for testing purposes)
  * @revision: revision register contents
  * @is_selfpowered: true when we are selfpowered
@@ -585,7 +588,7 @@ struct dwc3 {
         spinlock_t              lock;
         struct device           *dev;
 
-        struct dwc3_event_buffer *ev_buffs[DWC3_EVENT_BUFFERS_NUM];
+        struct dwc3_event_buffer *ev_buffs[DWC3_EVENT_BUFFERS_MAX];
         struct dwc3_ep          *eps[DWC3_ENDPOINTS_NUM];
 
         struct usb_gadget       gadget;
@@ -596,6 +599,7 @@ struct dwc3 {
 
         int                     irq;
 
+        u32                     num_event_buffers;
         u32                     maximum_speed;
         u32                     revision;
 
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 807737aec00e..b84418e88774 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -1925,7 +1925,7 @@ static irqreturn_t dwc3_interrupt(int irq, void *_dwc)
 
         spin_lock(&dwc->lock);
 
-        for (i = 0; i < DWC3_EVENT_BUFFERS_NUM; i++) {
+        for (i = 0; i < dwc->num_event_buffers; i++) {
                 irqreturn_t status;
 
                 status = dwc3_process_event_buf(dwc, i);