Create an IoT slot device on mangOH Red

linux_kernel_modules/mangoh/9-mangoh_red_dv2.mdef

@@ -4,11 +4,13 @@ cflags:
     -I${MANGOH_ROOT}/linux_kernel_modules/lsm6ds3
     -I${MANGOH_ROOT}/linux_kernel_modules/ltc294x
     -I${MANGOH_ROOT}/linux_kernel_modules/bq24296
+    -I${MANGOH_ROOT}/linux_kernel_modules/iot_slot
 }
 
 sources:
 {
     mangoh_red.c
+    mangoh_red_mux.c
 }
 
 params:

linux_kernel_modules/mangoh/9-mangoh_red_dv3.mdef

@@ -4,11 +4,13 @@ cflags:
     -I${MANGOH_ROOT}/linux_kernel_modules/lsm6ds3
     -I${MANGOH_ROOT}/linux_kernel_modules/ltc294x
     -I${MANGOH_ROOT}/linux_kernel_modules/bq24296
+    -I${MANGOH_ROOT}/linux_kernel_modules/iot_slot
 }
 
 sources:
 {
     mangoh_red.c
+    mangoh_red_mux.c
 }
 
 params:

linux_kernel_modules/mangoh/9-mangoh_red_dv4.mdef → linux_kernel_modules/mangoh/9-mangoh_red_dv5.mdef

@@ -4,14 +4,16 @@ cflags:
     -I${MANGOH_ROOT}/linux_kernel_modules/lsm6ds3
     -I${MANGOH_ROOT}/linux_kernel_modules/ltc294x
     -I${MANGOH_ROOT}/linux_kernel_modules/bq24296
+    -I${MANGOH_ROOT}/linux_kernel_modules/iot_slot
 }
 
 sources:
 {
     mangoh_red.c
+    mangoh_red_mux.c
 }
 
 params:
 {
-    revision = "dv4"
+    revision = "dv5"
 }

linux_kernel_modules/mangoh/mangoh_red_mux.c

+#include <linux/kernel.h>
+#include <linux/gpio.h>
+#include "mangoh_red_mux.h"
+
+static struct platform_device *board_device;
+
+static int sdio_mux_gpio;
+static struct mutex sdio_mutex;
+static enum sdio_selection sdio_current_selection;
+static unsigned int sdio_num_requested;
+
+static int pcm_mux_gpio;
+static struct mutex pcm_mutex;
+static enum pcm_selection pcm_current_selection;
+static unsigned int pcm_num_requested;
+
+
+int mangoh_red_mux_init(struct platform_device *pdev, int sdio_gpio,
+			int pcm_gpio)
+{
+	int ret;
+	struct device *device = &pdev->dev;
+	board_device = pdev;
+
+	sdio_mux_gpio = sdio_gpio;
+	pcm_mux_gpio = pcm_gpio;
+
+	dev_info(device,
+		"Initializing mangOH mux with sdio_gpio=%d, pcm_gpio=%d\n",
+		sdio_mux_gpio, pcm_mux_gpio);
+
+	ret = devm_gpio_request_one(device, sdio_mux_gpio,
+				    GPIOF_OUT_INIT_HIGH,
+				    "sdio mux");
+	if (ret != 0) {
+		dev_err(device, "Couldn't acquire GPIO for SDIO mux\n");
+		return ret;
+	}
+
+	ret = devm_gpio_request_one(device, pcm_mux_gpio,
+				    GPIOF_OUT_INIT_HIGH,
+				    "pcm mux");
+	if (ret != 0) {
+		dev_err(device, "Couldn't acquire GPIO for PCM mux\n");
+		/* Release the SDIO mux gpio that was acquired previously */
+		devm_gpio_free(device, sdio_mux_gpio);
+		return ret;
+	}
+
+	mutex_init(&sdio_mutex);
+	mutex_init(&pcm_mutex);
+
+	/* Initialize based on hardware defaults */
+	sdio_current_selection = SDIO_SELECTION_SD_CARD_SLOT;
+	pcm_current_selection = PCM_SELECTION_ONBOARD;
+
+	sdio_num_requested = 0;
+	pcm_num_requested = 0;
+
+	return 0;
+}
+
+void mangoh_red_mux_deinit(void)
+{
+	struct device *device = &board_device->dev;
+	devm_gpio_free(device, pcm_mux_gpio);
+	devm_gpio_free(device, sdio_mux_gpio);
+}
+
+int mangoh_red_mux_sdio_select(enum sdio_selection selection)
+{
+	int ret = 0;
+	dev_info(&board_device->dev, "SDIO mux: selecting %s\n",
+		 (selection == SDIO_SELECTION_SD_CARD_SLOT ?
+		  "SD card slot" : "IoT slot"));
+	mutex_lock(&sdio_mutex);
+	if (selection == sdio_current_selection)
+		sdio_num_requested++;
+	else {
+		if (sdio_num_requested == 0) {
+			ret = gpio_direction_output(
+				sdio_mux_gpio,
+				selection == SDIO_SELECTION_SD_CARD_SLOT ?
+				1 : 0);
+			if (ret != 0) {
+				dev_err(&board_device->dev,
+					"Couldn't set sdio mux\n");
+				goto unlock;
+			}
+			sdio_current_selection = selection;
+			sdio_num_requested++;
+		} else {
+			ret = -EBUSY;
+		}
+	}
+
+unlock:
+	mutex_unlock(&sdio_mutex);
+
+	return ret;
+}
+
+int mangoh_red_mux_sdio_release(enum sdio_selection selection)
+{
+	int ret = 0;
+	mutex_lock(&sdio_mutex);
+
+	if (selection != sdio_current_selection) {
+		dev_err(&board_device->dev,
+			"Trying to release SDIO mux, but the current selection differs from what the client specified\n");
+		ret = -EACCES;
+		goto unlock;
+	}
+
+	if (sdio_num_requested != 0) {
+		sdio_num_requested--;
+	} else {
+		dev_err(&board_device->dev,
+			"Couldn't release SDIO since it wasn't requested\n");
+		ret = -ENOLCK;
+	}
+unlock:
+	mutex_unlock(&sdio_mutex);
+
+	return ret;
+}
+
+int mangoh_red_mux_pcm_select(enum pcm_selection selection)
+{
+	int ret = 0;
+	dev_info(&board_device->dev, "PCM mux: selecting %s\n",
+		 (selection == PCM_SELECTION_ONBOARD ? "onboard" : "IoT slot"));
+	mutex_lock(&pcm_mutex);
+	if (selection == pcm_current_selection)
+		pcm_num_requested++;
+	else {
+		if (pcm_num_requested == 0) {
+			ret = gpio_direction_output(
+				pcm_mux_gpio,
+				selection == PCM_SELECTION_ONBOARD ?
+				1 : 0);
+			if (ret != 0) {
+				dev_err(&board_device->dev,
+					"Couldn't set pcm mux\n");
+				goto unlock;
+			}
+			pcm_current_selection = selection;
+			pcm_num_requested++;
+		} else {
+			ret = -EBUSY;
+		}
+	}
+
+unlock:
+	mutex_unlock(&pcm_mutex);
+
+	return ret;
+}
+
+int mangoh_red_mux_pcm_release(enum pcm_selection selection)
+{
+	int ret = 0;
+	mutex_lock(&pcm_mutex);
+
+	if (selection != pcm_current_selection) {
+		dev_err(
+			&board_device->dev,
+			"Trying to release PCM mux, but the current selection differs from what the client specified\n");
+		ret = -EACCES;
+		goto unlock;
+	}
+
+	if (pcm_num_requested != 0) {
+		pcm_num_requested--;
+	} else {
+		dev_err(&board_device->dev,
+			"Couldn't release PCM since it wasn't requested\n");
+		ret = -ENOLCK;
+	}
+unlock:
+	mutex_unlock(&pcm_mutex);
+
+	return ret;
+}

linux_kernel_modules/mangoh/mangoh_red_mux.h

+#ifndef MANGOH_RED_MUX_H
+#define MANGOH_RED_MUX_H
+
+#include <linux/platform_device.h>
+
+enum sdio_selection {
+	SDIO_SELECTION_SD_CARD_SLOT,
+	SDIO_SELECTION_IOT_SLOT,
+};
+
+enum pcm_selection {
+	PCM_SELECTION_IOT_SLOT,
+	PCM_SELECTION_ONBOARD,
+};
+
+int mangoh_red_mux_init(struct platform_device *pdev, int sdio_gpio, int pcm_gpio);
+void mangoh_red_mux_deinit(void);
+int mangoh_red_mux_sdio_select(enum sdio_selection selection);
+int mangoh_red_mux_sdio_release(enum sdio_selection selection);
+int mangoh_red_mux_pcm_select(enum pcm_selection selection);
+int mangoh_red_mux_pcm_release(enum pcm_selection selection);
+
+#endif /* MANGOH_RED_MUX_H */

mangOH_Red.sdef

@@ -45,8 +45,8 @@ interfaceSearch:
 kernelModules:
 {
     // $MANGOH_ROOT/linux_kernel_modules/mangoh/9-mangoh_red_dv2
-    // $MANGOH_ROOT/linux_kernel_modules/mangoh/9-mangoh_red_dv3
-    $MANGOH_ROOT/linux_kernel_modules/mangoh/9-mangoh_red_dv4
+    $MANGOH_ROOT/linux_kernel_modules/mangoh/9-mangoh_red_dv3
+    // $MANGOH_ROOT/linux_kernel_modules/mangoh/9-mangoh_red_dv5
 
     // cp2130 required for MT7697 WiFi/BT
     $MANGOH_ROOT/linux_kernel_modules/cp2130/0-cp2130
@@ -68,6 +68,8 @@ kernelModules:
     $MANGOH_ROOT/linux_kernel_modules/bmi160/3-bmi160
     $MANGOH_ROOT/linux_kernel_modules/bmi160/4-bmi160-i2c
 
+    $MANGOH_ROOT/linux_kernel_modules/iot_slot/0-iot_slot
+
     $MANGOH_ROOT/linux_kernel_modules/mt7697q/1-mt7697q
     $MANGOH_ROOT/linux_kernel_modules/mt7697wifi/2-mt7697wifi_core