hw/arm: Add npcm7xx emc model

This is a 10/100 ethernet device that has several features.
Only the ones needed by the Linux driver have been implemented.
See npcm7xx_emc.c for a list of unimplemented features.

Reviewed-by: Hao Wu <wuhaotsh@google.com>
Reviewed-by: Avi Fishman <avi.fishman@nuvoton.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Doug Evans <dje@google.com>
Message-id: 20210218212453.831406-3-dje@google.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

3 files changed, 52 insertions, 3 deletions

diff --git a/docs/system/arm/nuvoton.rst b/docs/system/arm/nuvoton.rst
index 34fc799b2d..f9fb9224da 100644
--- a/docs/system/arm/nuvoton.rst
+++ b/docs/system/arm/nuvoton.rst
@@ -44,6 +44,7 @@ Supported devices
  * Analog to Digital Converter (ADC)
  * Pulse Width Modulation (PWM)
  * SMBus controller (SMBF)
+ * Ethernet controller (EMC)
 
 Missing devices
 ---------------
@@ -57,7 +58,7 @@ Missing devices
    * Shared memory (SHM)
    * eSPI slave interface
 
- * Ethernet controllers (GMAC and EMC)
+ * Ethernet controller (GMAC)
  * USB device (USBD)
  * Peripheral SPI controller (PSPI)
  * SD/MMC host
diff --git a/hw/arm/npcm7xx.c b/hw/arm/npcm7xx.c
index f8950f9470..9bd1e83f02 100644
--- a/hw/arm/npcm7xx.c
+++ b/hw/arm/npcm7xx.c
@@ -82,6 +82,8 @@ enum NPCM7xxInterrupt {
     NPCM7XX_UART1_IRQ,
     NPCM7XX_UART2_IRQ,
     NPCM7XX_UART3_IRQ,
+    NPCM7XX_EMC1RX_IRQ          = 15,
+    NPCM7XX_EMC1TX_IRQ,
     NPCM7XX_TIMER0_IRQ          = 32,   /* Timer Module 0 */
     NPCM7XX_TIMER1_IRQ,
     NPCM7XX_TIMER2_IRQ,
@@ -120,6 +122,8 @@ enum NPCM7xxInterrupt {
     NPCM7XX_SMBUS15_IRQ,
     NPCM7XX_PWM0_IRQ            = 93,   /* PWM module 0 */
     NPCM7XX_PWM1_IRQ,                   /* PWM module 1 */
+    NPCM7XX_EMC2RX_IRQ          = 114,
+    NPCM7XX_EMC2TX_IRQ,
     NPCM7XX_GPIO0_IRQ           = 116,
     NPCM7XX_GPIO1_IRQ,
     NPCM7XX_GPIO2_IRQ,
@@ -188,6 +192,12 @@ static const hwaddr npcm7xx_smbus_addr[] = {
     0xf008f000,
 };
 
+/* Register base address for each EMC Module */
+static const hwaddr npcm7xx_emc_addr[] = {
+    0xf0825000,
+    0xf0826000,
+};
+
 static const struct {
     hwaddr regs_addr;
     uint32_t unconnected_pins;
@@ -406,6 +416,10 @@ static void npcm7xx_init(Object *obj)
     for (i = 0; i < ARRAY_SIZE(s->pwm); i++) {
         object_initialize_child(obj, "pwm[*]", &s->pwm[i], TYPE_NPCM7XX_PWM);
     }
+
+    for (i = 0; i < ARRAY_SIZE(s->emc); i++) {
+        object_initialize_child(obj, "emc[*]", &s->emc[i], TYPE_NPCM7XX_EMC);
+    }
 }
 
 static void npcm7xx_realize(DeviceState *dev, Error **errp)
@@ -590,6 +604,40 @@ static void npcm7xx_realize(DeviceState *dev, Error **errp)
     }
 
     /*
+     * EMC Modules. Cannot fail.
+     * The mapping of the device to its netdev backend works as follows:
+     * emc[i] = nd_table[i]
+     * This works around the inability to specify the netdev property for the
+     * emc device: it's not pluggable and thus the -device option can't be
+     * used.
+     */
+    QEMU_BUILD_BUG_ON(ARRAY_SIZE(npcm7xx_emc_addr) != ARRAY_SIZE(s->emc));
+    QEMU_BUILD_BUG_ON(ARRAY_SIZE(s->emc) != 2);
+    for (i = 0; i < ARRAY_SIZE(s->emc); i++) {
+        s->emc[i].emc_num = i;
+        SysBusDevice *sbd = SYS_BUS_DEVICE(&s->emc[i]);
+        if (nd_table[i].used) {
+            qemu_check_nic_model(&nd_table[i], TYPE_NPCM7XX_EMC);
+            qdev_set_nic_properties(DEVICE(sbd), &nd_table[i]);
+        }
+        /*
+         * The device exists regardless of whether it's connected to a QEMU
+         * netdev backend. So always instantiate it even if there is no
+         * backend.
+         */
+        sysbus_realize(sbd, &error_abort);
+        sysbus_mmio_map(sbd, 0, npcm7xx_emc_addr[i]);
+        int tx_irq = i == 0 ? NPCM7XX_EMC1TX_IRQ : NPCM7XX_EMC2TX_IRQ;
+        int rx_irq = i == 0 ? NPCM7XX_EMC1RX_IRQ : NPCM7XX_EMC2RX_IRQ;
+        /*
+         * N.B. The values for the second argument sysbus_connect_irq are
+         * chosen to match the registration order in npcm7xx_emc_realize.
+         */
+        sysbus_connect_irq(sbd, 0, npcm7xx_irq(s, tx_irq));
+        sysbus_connect_irq(sbd, 1, npcm7xx_irq(s, rx_irq));
+    }
+
+    /*
      * Flash Interface Unit (FIU). Can fail if incorrect number of chip selects
      * specified, but this is a programming error.
      */
@@ -649,8 +697,6 @@ static void npcm7xx_realize(DeviceState *dev, Error **errp)
     create_unimplemented_device("npcm7xx.vcd",          0xf0810000,  64 * KiB);
     create_unimplemented_device("npcm7xx.ece",          0xf0820000,   8 * KiB);
     create_unimplemented_device("npcm7xx.vdma",         0xf0822000,   8 * KiB);
-    create_unimplemented_device("npcm7xx.emc1",         0xf0825000,   4 * KiB);
-    create_unimplemented_device("npcm7xx.emc2",         0xf0826000,   4 * KiB);
     create_unimplemented_device("npcm7xx.usbd[0]",      0xf0830000,   4 * KiB);
     create_unimplemented_device("npcm7xx.usbd[1]",      0xf0831000,   4 * KiB);
     create_unimplemented_device("npcm7xx.usbd[2]",      0xf0832000,   4 * KiB);
diff --git a/include/hw/arm/npcm7xx.h b/include/hw/arm/npcm7xx.h
index cea1bd1f62..d32849a456 100644
--- a/include/hw/arm/npcm7xx.h
+++ b/include/hw/arm/npcm7xx.h
@@ -26,6 +26,7 @@
 #include "hw/misc/npcm7xx_gcr.h"
 #include "hw/misc/npcm7xx_pwm.h"
 #include "hw/misc/npcm7xx_rng.h"
+#include "hw/net/npcm7xx_emc.h"
 #include "hw/nvram/npcm7xx_otp.h"
 #include "hw/timer/npcm7xx_timer.h"
 #include "hw/ssi/npcm7xx_fiu.h"
@@ -90,6 +91,7 @@ typedef struct NPCM7xxState {
     EHCISysBusState     ehci;
     OHCISysBusState     ohci;
     NPCM7xxFIUState     fiu[2];
+    NPCM7xxEMCState     emc[2];
 } NPCM7xxState;
 
 #define TYPE_NPCM7XX    "npcm7xx"