usb: dwc2: Add support for STM32F429/439/469 USB OTG HS/FS in FS mode (internal PHY)

This patch introduces a new parameter to activate USB OTG HS/FS core
embedded phy transceiver. The STM32F4x9 SoC uses the GGPIO register
to enable the transceiver.
Also add the dwc2_set_params function for stm32f4 otg fs.

Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Bruno Herrera <bruherrera@gmail.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/dwc2/core.h

@@ -423,6 +423,10 @@ enum dwc2_ep0_state {
  *			needed.
  *			0 - No (default)
  *			1 - Yes
+ * @activate_stm_fs_transceiver: Activate internal transceiver using GGPIO
+ *			register.
+ *			0 - Deactivate the transceiver (default)
+ *			1 - Activate the transceiver
  * @g_dma:              Enables gadget dma usage (default: autodetect).
  * @g_dma_desc:         Enables gadget descriptor DMA (default: autodetect).
  * @g_rx_fifo_size:	The periodic rx fifo size for the device, in
@@ -477,6 +481,7 @@ struct dwc2_core_params {
 	bool uframe_sched;
 	bool external_id_pin_ctl;
 	bool hibernation;
+	bool activate_stm_fs_transceiver;
 	u16 max_packet_count;
 	u32 max_transfer_size;
 	u32 ahbcfg;

drivers/usb/dwc2/hcd.c

@@ -121,7 +121,7 @@ static void dwc2_init_fs_ls_pclk_sel(struct dwc2_hsotg *hsotg)
 
 static int dwc2_fs_phy_init(struct dwc2_hsotg *hsotg, bool select_phy)
 {
-	u32 usbcfg, i2cctl;
+	u32 usbcfg, ggpio, i2cctl;
 	int retval = 0;
 
 	/*
@@ -145,6 +145,19 @@ static int dwc2_fs_phy_init(struct dwc2_hsotg *hsotg, bool select_phy)
 				return retval;
 			}
 		}
+
+		if (hsotg->params.activate_stm_fs_transceiver) {
+			ggpio = dwc2_readl(hsotg->regs + GGPIO);
+			if (!(ggpio & GGPIO_STM32_OTG_GCCFG_PWRDWN)) {
+				dev_dbg(hsotg->dev, "Activating transceiver\n");
+				/*
+				 * STM32F4x9 uses the GGPIO register as general
+				 * core configuration register.
+				 */
+				ggpio |= GGPIO_STM32_OTG_GCCFG_PWRDWN;
+				dwc2_writel(ggpio, hsotg->regs + GGPIO);
+			}
+		}
 	}
 
 	/*

drivers/usb/dwc2/hw.h

@@ -225,6 +225,8 @@
 
 #define GPVNDCTL			HSOTG_REG(0x0034)
 #define GGPIO				HSOTG_REG(0x0038)
+#define GGPIO_STM32_OTG_GCCFG_PWRDWN	BIT(16)
+
 #define GUID				HSOTG_REG(0x003c)
 #define GSNPSID				HSOTG_REG(0x0040)
 #define GHWCFG1				HSOTG_REG(0x0044)

drivers/usb/dwc2/params.c

@@ -120,6 +120,22 @@ static void dwc2_set_amcc_params(struct dwc2_hsotg *hsotg)
 	p->ahbcfg = GAHBCFG_HBSTLEN_INCR16 << GAHBCFG_HBSTLEN_SHIFT;
 }
 
+static void dwc2_set_stm32f4x9_fsotg_params(struct dwc2_hsotg *hsotg)
+{
+	struct dwc2_core_params *p = &hsotg->params;
+
+	p->otg_cap = DWC2_CAP_PARAM_NO_HNP_SRP_CAPABLE;
+	p->speed = DWC2_SPEED_PARAM_FULL;
+	p->host_rx_fifo_size = 128;
+	p->host_nperio_tx_fifo_size = 96;
+	p->host_perio_tx_fifo_size = 96;
+	p->max_packet_count = 256;
+	p->phy_type = DWC2_PHY_TYPE_PARAM_FS;
+	p->i2c_enable = false;
+	p->uframe_sched = false;
+	p->activate_stm_fs_transceiver = true;
+}
+
 const struct of_device_id dwc2_of_match_table[] = {
 	{ .compatible = "brcm,bcm2835-usb", .data = dwc2_set_bcm_params },
 	{ .compatible = "hisilicon,hi6220-usb", .data = dwc2_set_his_params  },
@@ -133,6 +149,9 @@ const struct of_device_id dwc2_of_match_table[] = {
 	{ .compatible = "amlogic,meson-gxbb-usb",
 	  .data = dwc2_set_amlogic_params },
 	{ .compatible = "amcc,dwc-otg", .data = dwc2_set_amcc_params },
+	{ .compatible = "st,stm32f4x9-fsotg",
+	  .data = dwc2_set_stm32f4x9_fsotg_params },
+	{ .compatible = "st,stm32f4x9-hsotg" },
 	{},
 };
 MODULE_DEVICE_TABLE(of, dwc2_of_match_table);