stm32/ulpi: Add USB3320 ULPI low-power functions.

This driver allows switching USB3320 ULPI to low-power mode.  It is ported/
adapted from ST code, stm32f7xx_lp_modes.c, which is BSD-3 licensed code.

3 files changed, 227 insertions, 0 deletions

diff --git a/ports/stm32/Makefile b/ports/stm32/Makefile
index 85b25c77e..34d586674 100644
--- a/ports/stm32/Makefile
+++ b/ports/stm32/Makefile
@@ -279,6 +279,7 @@ SRC_C += \
 	pyb_spi.c \
 	qspi.c \
 	uart.c \
+	ulpi.c \
 	can.c \
 	fdcan.c \
 	pyb_can.c \
diff --git a/ports/stm32/ulpi.c b/ports/stm32/ulpi.c
new file mode 100644
index 000000000..a118ca57f
--- /dev/null
+++ b/ports/stm32/ulpi.c
@@ -0,0 +1,194 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * Copyright (c) 2016 STMicroelectronics. All rights reserved.
+ *
+ * This software component is licensed by ST under BSD 3-Clause license,
+ * the "License"; You may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at:
+ *                        opensource.org/licenses/BSD-3-Clause
+ *
+ * USB3320 ULPI functions ported from stm32f7xx_lp_modes.c
+ *
+ * Source file: https://github.com/STMicroelectronics/STM32CubeF7/blob/v1.15.0/Projects/STM32746G-Discovery/Examples/PWR/PWR_CurrentConsumption/Src/stm32f7xx_lp_modes.c
+ */
+
+#include <stdint.h>
+#include "py/mphal.h"
+#include "pin_static_af.h"
+#include "ulpi.h"
+
+#if MICROPY_HW_USB_HS_ULPI3320
+
+#include STM32_HAL_H
+
+#define USBULPI_PHYCR           ((uint32_t)(0x40040000 + 0x034))
+#define USBULPI_D07             ((uint32_t)0x000000FF)
+#define USBULPI_New             ((uint32_t)0x02000000)
+#define USBULPI_RW              ((uint32_t)0x00400000)
+#define USBULPI_S_BUSY          ((uint32_t)0x04000000)
+#define USBULPI_S_DONE          ((uint32_t)0x08000000)
+#define USBULPI_TIMEOUT_COUNT   (100)
+
+#define USB_OTG_READ_REG32(reg)  (*(__IO uint32_t *)(reg))
+#define USB_OTG_WRITE_REG32(reg,value) (*(__IO uint32_t *)(reg) = (value))
+
+/**
+  * @brief  Read CR value
+  * @param  Addr the Address of the ULPI Register
+  * @retval Returns value of PHY CR register
+  */
+static uint32_t USB_ULPI_Read(uint32_t Addr) {
+    uint32_t val = 0;
+    uint32_t timeout = USBULPI_TIMEOUT_COUNT;
+
+    USB_OTG_WRITE_REG32(USBULPI_PHYCR, USBULPI_New | (Addr << 16));
+    val = USB_OTG_READ_REG32(USBULPI_PHYCR);
+    while (((val & USBULPI_S_DONE) == 0) && (timeout--)) {
+        val = USB_OTG_READ_REG32(USBULPI_PHYCR);
+    }
+    val = USB_OTG_READ_REG32(USBULPI_PHYCR);
+    return val & 0x000000ff;
+}
+
+/**
+  * @brief  Write CR value
+  * @param  Addr the Address of the ULPI Register
+  * @param  Data Data to write
+  * @retval Returns value of PHY CR register
+  */
+static uint32_t USB_ULPI_Write(uint32_t Addr, uint32_t Data) {
+    uint32_t val;
+    uint32_t timeout = USBULPI_TIMEOUT_COUNT;
+
+    USB_OTG_WRITE_REG32(USBULPI_PHYCR, USBULPI_New | USBULPI_RW | (Addr << 16) | (Data & 0x000000ff));
+    val = USB_OTG_READ_REG32(USBULPI_PHYCR);
+    while (((val & USBULPI_S_DONE) == 0) && (timeout--)) {
+        val = USB_OTG_READ_REG32(USBULPI_PHYCR);
+    }
+
+    val = USB_OTG_READ_REG32(USBULPI_PHYCR);
+    return 0;
+}
+
+/**
+  * @brief  This function configures the USB PHY to enter the low power mode
+  * @param  None
+  * @retval None
+  */
+int ulpi_enter_low_power(void) {
+    uint32_t regval = 0;
+
+    // Disable ULPI_CLK by accessing ULPI_PHY
+    // Read Vendor ID : (Low, High) 0x24,0x04 for USB3300
+    regval = USB_ULPI_Read(0x00);
+    if (regval != 0x24) {
+        return MP_EIO;
+    }
+
+    regval = USB_ULPI_Read(0x01);
+    if (regval != 0x04) {
+        return MP_EIO;
+    }
+
+    // Read Product ID
+    regval = USB_ULPI_Read(0x02);
+    if (regval != 0x07) {
+        return MP_EIO;
+    }
+
+    regval = USB_ULPI_Read(0x03);
+    if (regval != 0x00) {
+        return MP_EIO;
+    }
+
+    // Write to scratch register the pattern 0x55
+    USB_ULPI_Write(0x16, 0x55);
+    // Read to scratch Register and check-it again the written Pattern
+    regval = USB_ULPI_Read(0x16);
+    if (regval != 0x55) {
+        return MP_EIO;
+    }
+
+    // Write to scratch register the pattern 0xAA
+    USB_ULPI_Write(0x16, 0xAA);
+    // Read to scratch Register and check-it again the written Pattern
+    regval = USB_ULPI_Read(0x16);
+    if (regval != 0xAA) {
+        return MP_EIO;
+    }
+
+    // Read InterfaceControl reg
+    regval = USB_ULPI_Read(0x07);
+
+    // Write InterfaceControl reg,to disable PullUp on stp,
+    // to avoid USB_PHY wake up when MCU entering standby
+    USB_ULPI_Write(0x07, regval | 0x80);
+
+    // Read InterfaceControl reg
+    regval = USB_ULPI_Read(0x07);
+    if (regval != 0x80) {
+        return MP_EIO;
+    }
+
+    // Read FunctionControl reg
+    regval = USB_ULPI_Read(0x04);
+
+    // Reg 0x40 has a different value if USB is disconnected
+    if (regval != 0x40 && regval != 0x45) {
+        return MP_EIO;
+    }
+
+    // Write FunctionControl reg,to put PHY into LowPower mode
+    USB_ULPI_Write(0x04, regval & (~0x40));
+
+    // Read FunctionControl reg again
+    regval = USB_ULPI_Read(0x04);
+    if (regval != 0x00) {
+        return MP_EIO;
+    }
+
+    // Wait for the transceiver clock to stop.
+    HAL_Delay(10);
+
+    return 0;
+}
+
+/**
+ * @brief  This function wakeup the USB PHY from the Low power mode
+ * @param  None
+ * @retval None
+ */
+int ulpi_leave_low_power(void) {
+    // Configure STP as an output pin
+    mp_hal_pin_config(MICROPY_HW_USB_HS_ULPI_STP, MP_HAL_PIN_MODE_OUTPUT, MP_HAL_PIN_PULL_NONE, 0);
+    mp_hal_pin_config_speed(MICROPY_HW_USB_HS_ULPI_STP, MP_HAL_PIN_SPEED_VERY_HIGH);
+
+    // Configure DIR as an input pin
+    mp_hal_pin_config(MICROPY_HW_USB_HS_ULPI_DIR, MP_HAL_PIN_MODE_INPUT, MP_HAL_PIN_PULL_NONE, 0);
+    mp_hal_pin_config_speed(MICROPY_HW_USB_HS_ULPI_DIR, MP_HAL_PIN_SPEED_VERY_HIGH);
+
+    // Set STP pin high
+    mp_hal_pin_high(MICROPY_HW_USB_HS_ULPI_STP);
+
+    // Wait for DIR to go low
+    for (uint32_t i = 0; i < 500; i++, HAL_Delay(1)) {
+        if (mp_hal_pin_read(MICROPY_HW_USB_HS_ULPI_DIR) == 0) {
+            break;
+        }
+    }
+
+    // Save DIR pin state before switching to alternate function
+    int dir_state = mp_hal_pin_read(MICROPY_HW_USB_HS_ULPI_DIR);
+
+    // Revert STP/DIR to their alternate functions
+    mp_hal_pin_config(MICROPY_HW_USB_HS_ULPI_STP, MP_HAL_PIN_MODE_ALT, MP_HAL_PIN_PULL_NONE, GPIO_AF10_OTG_HS);
+    mp_hal_pin_config_speed(MICROPY_HW_USB_HS_ULPI_STP, MP_HAL_PIN_SPEED_VERY_HIGH);
+
+    mp_hal_pin_config(MICROPY_HW_USB_HS_ULPI_DIR, MP_HAL_PIN_MODE_ALT, MP_HAL_PIN_PULL_NONE, GPIO_AF10_OTG_HS);
+    mp_hal_pin_config_speed(MICROPY_HW_USB_HS_ULPI_DIR, MP_HAL_PIN_SPEED_VERY_HIGH);
+
+    return (dir_state == 0) ? 0 : -1;
+}
+
+#endif // MICROPY_HW_USB_HS_ULPI3320
diff --git a/ports/stm32/ulpi.h b/ports/stm32/ulpi.h
new file mode 100644
index 000000000..1464110e7
--- /dev/null
+++ b/ports/stm32/ulpi.h
@@ -0,0 +1,32 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2022 Damien P. George
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#ifndef MICROPY_INCLUDED_STM32_ULPI_H
+#define MICROPY_INCLUDED_STM32_ULPI_H
+
+int ulpi_enter_low_power(void);
+int ulpi_leave_low_power(void);
+
+#endif // MICROPY_INCLUDED_STM32_ULPI_H