hw/ssi: Add Nuvoton PSPI Module

Nuvoton's PSPI is a general purpose SPI module which enables
connections to SPI-based peripheral devices.

Signed-off-by: Hao Wu <wuhaotsh@google.com>
Reviewed-by: Chris Rauer <crauer@google.com>
Reviewed-by: Philippe Mathieu-Daude <philmd@linaro.org>
Message-id: 20230208235433.3989937-3-wuhaotsh@google.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

3 files changed, 227 insertions, 1 deletions

diff --git a/hw/ssi/meson.build b/hw/ssi/meson.build
index 702aa5e..904a471 100644
--- a/hw/ssi/meson.build
+++ b/hw/ssi/meson.build
@@ -1,6 +1,6 @@
 softmmu_ss.add(when: 'CONFIG_ASPEED_SOC', if_true: files('aspeed_smc.c'))
 softmmu_ss.add(when: 'CONFIG_MSF2', if_true: files('mss-spi.c'))
-softmmu_ss.add(when: 'CONFIG_NPCM7XX', if_true: files('npcm7xx_fiu.c'))
+softmmu_ss.add(when: 'CONFIG_NPCM7XX', if_true: files('npcm7xx_fiu.c', 'npcm_pspi.c'))
 softmmu_ss.add(when: 'CONFIG_PL022', if_true: files('pl022.c'))
 softmmu_ss.add(when: 'CONFIG_SIFIVE_SPI', if_true: files('sifive_spi.c'))
 softmmu_ss.add(when: 'CONFIG_SSI', if_true: files('ssi.c'))
diff --git a/hw/ssi/npcm_pspi.c b/hw/ssi/npcm_pspi.c
new file mode 100644
index 0000000..3fb9350
--- /dev/null
+++ b/hw/ssi/npcm_pspi.c
@@ -0,0 +1,221 @@
+/*
+ * Nuvoton NPCM Peripheral SPI Module (PSPI)
+ *
+ * Copyright 2023 Google LLC
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ */
+
+#include "qemu/osdep.h"
+
+#include "hw/irq.h"
+#include "hw/registerfields.h"
+#include "hw/ssi/npcm_pspi.h"
+#include "migration/vmstate.h"
+#include "qapi/error.h"
+#include "qemu/error-report.h"
+#include "qemu/log.h"
+#include "qemu/module.h"
+#include "qemu/units.h"
+
+#include "trace.h"
+
+REG16(PSPI_DATA, 0x0)
+REG16(PSPI_CTL1, 0x2)
+    FIELD(PSPI_CTL1, SPIEN, 0,  1)
+    FIELD(PSPI_CTL1, MOD,   2,  1)
+    FIELD(PSPI_CTL1, EIR,   5,  1)
+    FIELD(PSPI_CTL1, EIW,   6,  1)
+    FIELD(PSPI_CTL1, SCM,   7,  1)
+    FIELD(PSPI_CTL1, SCIDL, 8,  1)
+    FIELD(PSPI_CTL1, SCDV,  9,  7)
+REG16(PSPI_STAT, 0x4)
+    FIELD(PSPI_STAT, BSY,  0,  1)
+    FIELD(PSPI_STAT, RBF,  1,  1)
+
+static void npcm_pspi_update_irq(NPCMPSPIState *s)
+{
+    int level = 0;
+
+    /* Only fire IRQ when the module is enabled. */
+    if (FIELD_EX16(s->regs[R_PSPI_CTL1], PSPI_CTL1, SPIEN)) {
+        /* Update interrupt as BSY is cleared. */
+        if ((!FIELD_EX16(s->regs[R_PSPI_STAT], PSPI_STAT, BSY)) &&
+            FIELD_EX16(s->regs[R_PSPI_CTL1], PSPI_CTL1, EIW)) {
+            level = 1;
+        }
+
+        /* Update interrupt as RBF is set. */
+        if (FIELD_EX16(s->regs[R_PSPI_STAT], PSPI_STAT, RBF) &&
+            FIELD_EX16(s->regs[R_PSPI_CTL1], PSPI_CTL1, EIR)) {
+            level = 1;
+        }
+    }
+    qemu_set_irq(s->irq, level);
+}
+
+static uint16_t npcm_pspi_read_data(NPCMPSPIState *s)
+{
+    uint16_t value = s->regs[R_PSPI_DATA];
+
+    /* Clear stat bits as the value are read out. */
+    s->regs[R_PSPI_STAT] = 0;
+
+    return value;
+}
+
+static void npcm_pspi_write_data(NPCMPSPIState *s, uint16_t data)
+{
+    uint16_t value = 0;
+
+    if (FIELD_EX16(s->regs[R_PSPI_CTL1], PSPI_CTL1, MOD)) {
+        value = ssi_transfer(s->spi, extract16(data, 8, 8)) << 8;
+    }
+    value |= ssi_transfer(s->spi, extract16(data, 0, 8));
+    s->regs[R_PSPI_DATA] = value;
+
+    /* Mark data as available */
+    s->regs[R_PSPI_STAT] = R_PSPI_STAT_BSY_MASK | R_PSPI_STAT_RBF_MASK;
+}
+
+/* Control register read handler. */
+static uint64_t npcm_pspi_ctrl_read(void *opaque, hwaddr addr,
+                                    unsigned int size)
+{
+    NPCMPSPIState *s = opaque;
+    uint16_t value;
+
+    switch (addr) {
+    case A_PSPI_DATA:
+        value = npcm_pspi_read_data(s);
+        break;
+
+    case A_PSPI_CTL1:
+        value = s->regs[R_PSPI_CTL1];
+        break;
+
+    case A_PSPI_STAT:
+        value = s->regs[R_PSPI_STAT];
+        break;
+
+    default:
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: write to invalid offset 0x%" PRIx64 "\n",
+                      DEVICE(s)->canonical_path, addr);
+        return 0;
+    }
+    trace_npcm_pspi_ctrl_read(DEVICE(s)->canonical_path, addr, value);
+    npcm_pspi_update_irq(s);
+
+    return value;
+}
+
+/* Control register write handler. */
+static void npcm_pspi_ctrl_write(void *opaque, hwaddr addr, uint64_t v,
+                                 unsigned int size)
+{
+    NPCMPSPIState *s = opaque;
+    uint16_t value = v;
+
+    trace_npcm_pspi_ctrl_write(DEVICE(s)->canonical_path, addr, value);
+
+    switch (addr) {
+    case A_PSPI_DATA:
+        npcm_pspi_write_data(s, value);
+        break;
+
+    case A_PSPI_CTL1:
+        s->regs[R_PSPI_CTL1] = value;
+        break;
+
+    case A_PSPI_STAT:
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: write to read-only register PSPI_STAT: 0x%08"
+                      PRIx64 "\n", DEVICE(s)->canonical_path, v);
+        break;
+
+    default:
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: write to invalid offset 0x%" PRIx64 "\n",
+                      DEVICE(s)->canonical_path, addr);
+        return;
+    }
+    npcm_pspi_update_irq(s);
+}
+
+static const MemoryRegionOps npcm_pspi_ctrl_ops = {
+    .read = npcm_pspi_ctrl_read,
+    .write = npcm_pspi_ctrl_write,
+    .endianness = DEVICE_LITTLE_ENDIAN,
+    .valid = {
+        .min_access_size = 1,
+        .max_access_size = 2,
+        .unaligned = false,
+    },
+    .impl = {
+        .min_access_size = 2,
+        .max_access_size = 2,
+        .unaligned = false,
+    },
+};
+
+static void npcm_pspi_enter_reset(Object *obj, ResetType type)
+{
+    NPCMPSPIState *s = NPCM_PSPI(obj);
+
+    trace_npcm_pspi_enter_reset(DEVICE(obj)->canonical_path, type);
+    memset(s->regs, 0, sizeof(s->regs));
+}
+
+static void npcm_pspi_realize(DeviceState *dev, Error **errp)
+{
+    NPCMPSPIState *s = NPCM_PSPI(dev);
+    SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
+    Object *obj = OBJECT(dev);
+
+    s->spi = ssi_create_bus(dev, "pspi");
+    memory_region_init_io(&s->mmio, obj, &npcm_pspi_ctrl_ops, s,
+                          "mmio", 4 * KiB);
+    sysbus_init_mmio(sbd, &s->mmio);
+    sysbus_init_irq(sbd, &s->irq);
+}
+
+static const VMStateDescription vmstate_npcm_pspi = {
+    .name = "npcm-pspi",
+    .version_id = 0,
+    .minimum_version_id = 0,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT16_ARRAY(regs, NPCMPSPIState, NPCM_PSPI_NR_REGS),
+        VMSTATE_END_OF_LIST(),
+    },
+};
+
+
+static void npcm_pspi_class_init(ObjectClass *klass, void *data)
+{
+    ResettableClass *rc = RESETTABLE_CLASS(klass);
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->desc = "NPCM Peripheral SPI Module";
+    dc->realize = npcm_pspi_realize;
+    dc->vmsd = &vmstate_npcm_pspi;
+    rc->phases.enter = npcm_pspi_enter_reset;
+}
+
+static const TypeInfo npcm_pspi_types[] = {
+    {
+        .name = TYPE_NPCM_PSPI,
+        .parent = TYPE_SYS_BUS_DEVICE,
+        .instance_size = sizeof(NPCMPSPIState),
+        .class_init = npcm_pspi_class_init,
+    },
+};
+DEFINE_TYPES(npcm_pspi_types);
diff --git a/hw/ssi/trace-events b/hw/ssi/trace-events
index c707d4a..2d5bd2b 100644
--- a/hw/ssi/trace-events
+++ b/hw/ssi/trace-events
@@ -21,6 +21,11 @@ npcm7xx_fiu_ctrl_write(const char *id, uint64_t addr, uint32_t data) "%s offset:
 npcm7xx_fiu_flash_read(const char *id, int cs, uint64_t addr, unsigned int size, uint64_t value) "%s[%d] offset: 0x%08" PRIx64 " size: %u value: 0x%" PRIx64
 npcm7xx_fiu_flash_write(const char *id, unsigned cs, uint64_t addr, unsigned int size, uint64_t value) "%s[%d] offset: 0x%08" PRIx64 " size: %u value: 0x%" PRIx64
 
+# npcm_pspi.c
+npcm_pspi_enter_reset(const char *id, int reset_type) "%s reset type: %d"
+npcm_pspi_ctrl_read(const char *id, uint64_t addr, uint16_t data) "%s offset: 0x%03" PRIx64 " value: 0x%04" PRIx16
+npcm_pspi_ctrl_write(const char *id, uint64_t addr, uint16_t data) "%s offset: 0x%03" PRIx64 " value: 0x%04" PRIx16
+
 # ibex_spi_host.c
 
 ibex_spi_host_reset(const char *msg) "%s"