Board: stm32mp1: Add supply current boot information

For DK1/DK2 boards, check if power supply provides enough current
to allow the board to boot correctly.
ADC@0 channel 18 and 19 are connected to USB type-C CC1 and CC2
signals. The table below shows the behavior for different range of
CC1 or CC2:

  range       | power supply | red led |          console message
  (Volts)     |   (Amps)     | blinks  |
--------------|--------------|---------|-----------------------------------
[2.10 - 1.23[ |     3        |   NO    |    NO
[1.23 - 0.66[ |     1.5      | 3 times | WARNING 1.5A power supply detected
[0.66 - 0]    |     0.5      | 2 times | WARNING 500mA power supply detected

If detected current is < 3A, red led is kept ON after blinking.

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>

diff --git a/board/st/stm32mp1/stm32mp1.c b/board/st/stm32mp1/stm32mp1.c
index 282918089b508cf325c117d29102e7ad6b76266e..ff7790e310d7b44f4a39f54ddc5eb86637ee1797 100644 (file)
--- a/board/st/stm32mp1/stm32mp1.c
+++ b/board/st/stm32mp1/stm32mp1.c
@@ -2,9 +2,10 @@
 /*
  * Copyright (C) 2018, STMicroelectronics - All Rights Reserved
  */
+#include <common.h>
+#include <adc.h>
 #include <config.h>
 #include <clk.h>
-#include <common.h>
 #include <dm.h>
 #include <generic-phy.h>
 #include <led.h>
@@ -62,6 +63,10 @@ DECLARE_GLOBAL_DATA_PTR;
 #define STM32MP_GGPIO 0x38
 #define STM32MP_GGPIO_VBUS_SENSING BIT(21)
 
+#define USB_WARNING_LOW_THRESHOLD_UV   660000
+#define USB_START_LOW_THRESHOLD_UV     1230000
+#define USB_START_HIGH_THRESHOLD_UV    2100000
+
 int checkboard(void)
 {
        int ret;
@@ -294,6 +299,145 @@ clk_err:
        return ret;
 }
 
+static int get_led(struct udevice **dev, char *led_string)
+{
+       char *led_name;
+       int ret;
+
+       led_name = fdtdec_get_config_string(gd->fdt_blob, led_string);
+       if (!led_name) {
+               pr_debug("%s: could not find %s config string\n",
+                        __func__, led_string);
+               return -ENOENT;
+       }
+       ret = led_get_by_label(led_name, dev);
+       if (ret) {
+               debug("%s: get=%d\n", __func__, ret);
+               return ret;
+       }
+
+       return 0;
+}
+
+static int setup_led(enum led_state_t cmd)
+{
+       struct udevice *dev;
+       int ret;
+
+       ret = get_led(&dev, "u-boot,boot-led");
+       if (ret)
+               return ret;
+
+       ret = led_set_state(dev, cmd);
+       return ret;
+}
+
+static int board_check_usb_power(void)
+{
+       struct ofnode_phandle_args adc_args;
+       struct udevice *adc;
+       struct udevice *led;
+       ofnode node;
+       unsigned int raw;
+       int max_uV = 0;
+       int ret, uV, adc_count;
+       u8 i, nb_blink;
+
+       node = ofnode_path("/config");
+       if (!ofnode_valid(node)) {
+               debug("%s: no /config node?\n", __func__);
+               return -ENOENT;
+       }
+
+       /*
+        * Retrieve the ADC channels devices and get measurement
+        * for each of them
+        */
+       adc_count = ofnode_count_phandle_with_args(node, "st,adc_usb_pd",
+                                                  "#io-channel-cells");
+       if (adc_count < 0) {
+               if (adc_count == -ENOENT)
+                       return 0;
+
+               pr_err("%s: can't find adc channel (%d)\n", __func__,
+                      adc_count);
+
+               return adc_count;
+       }
+
+       for (i = 0; i < adc_count; i++) {
+               if (ofnode_parse_phandle_with_args(node, "st,adc_usb_pd",
+                                                  "#io-channel-cells", 0, i,
+                                                  &adc_args)) {
+                       pr_debug("%s: can't find /config/st,adc_usb_pd\n",
+                                __func__);
+                       return 0;
+               }
+
+               ret = uclass_get_device_by_ofnode(UCLASS_ADC, adc_args.node,
+                                                 &adc);
+
+               if (ret) {
+                       pr_err("%s: Can't get adc device(%d)\n", __func__,
+                              ret);
+                       return ret;
+               }
+
+               ret = adc_channel_single_shot(adc->name, adc_args.args[0],
+                                             &raw);
+               if (ret) {
+                       pr_err("%s: single shot failed for %s[%d]!\n",
+                              __func__, adc->name, adc_args.args[0]);
+                       return ret;
+               }
+               /* Convert to uV */
+               if (!adc_raw_to_uV(adc, raw, &uV)) {
+                       if (uV > max_uV)
+                               max_uV = uV;
+                       pr_debug("%s: %s[%02d] = %u, %d uV\n", __func__,
+                                adc->name, adc_args.args[0], raw, uV);
+               } else {
+                       pr_err("%s: Can't get uV value for %s[%d]\n",
+                              __func__, adc->name, adc_args.args[0]);
+               }
+       }
+
+       /*
+        * If highest value is inside 1.23 Volts and 2.10 Volts, that means
+        * board is plugged on an USB-C 3A power supply and boot process can
+        * continue.
+        */
+       if (max_uV > USB_START_LOW_THRESHOLD_UV &&
+           max_uV < USB_START_HIGH_THRESHOLD_UV)
+               return 0;
+
+       /* Display warning message and make u-boot,error-led blinking */
+       pr_err("\n*******************************************\n");
+
+       if (max_uV < USB_WARNING_LOW_THRESHOLD_UV) {
+               pr_err("*   WARNING 500mA power supply detected   *\n");
+               nb_blink = 2;
+       } else {
+               pr_err("* WARNING 1.5A power supply detected      *\n");
+               nb_blink = 3;
+       }
+
+       pr_err("* Current too low, use a 3A power supply! *\n");
+       pr_err("*******************************************\n\n");
+
+       ret = get_led(&led, "u-boot,error-led");
+       if (ret)
+               return ret;
+
+       for (i = 0; i < nb_blink * 2; i++) {
+               led_set_state(led, LEDST_TOGGLE);
+               mdelay(125);
+       }
+       led_set_state(led, LEDST_ON);
+
+       return 0;
+}
+
 int board_usb_cleanup(int index, enum usb_init_type init)
 {
        /* Reset usbotg */
@@ -428,5 +572,13 @@ int board_late_init(void)
        }
 #endif
 
+       /* for DK1/DK2 boards */
+       board_check_usb_power();
+
        return 0;
 }
+
+void board_quiesce_devices(void)
+{
+       setup_led(LEDST_OFF);
+}