[PATCH v2 5/5] hw/riscv/k230: Attach a standard SPI NOR flash

Add the optional spi-flash machine property and attach the selected
M25P80-compatible flash device to logical spi0 chip select 0.

Use the supplied MTD backend when present and retain the erased-flash
default otherwise. Document the machine option and add qtests for Standard
1-1-1 JEDEC identification and fixed-address reads.

Standard 1-1-1 transfers were also exercised manually through the K230
SDK U-Boot and Linux SPI paths against the attached flash.

The enhanced SPI and IDMA boot paths are outside the scope of this series.

Signed-off-by: Kangjie Huang <[email protected]>
---
 docs/system/riscv/k230.rst     |  1 +
 hw/riscv/Kconfig               |  1 +
 hw/riscv/k230.c                | 63 ++++++++++++++++++++++++++++++++++
 include/hw/riscv/k230.h        |  2 ++
 tests/qtest/k230-dw-ssi-test.c | 55 +++++++++++++++++++++++++++++
 5 files changed, 122 insertions(+)

diff --git a/docs/system/riscv/k230.rst b/docs/system/riscv/k230.rst
index 7a49cac95b..620ef263de 100644
--- a/docs/system/riscv/k230.rst
+++ b/docs/system/riscv/k230.rst
@@ -21,6 +21,7 @@ The ``k230`` machine supports the following devices:
 * 2 K230 Watchdog Timer
 * 5 UART
 * 3 K230 SSI controllers for SPI only
+* Optional SPI NOR flash on spi0 CS0
 
 Boot options
 ------------
diff --git a/hw/riscv/Kconfig b/hw/riscv/Kconfig
index 60a260691c..9d59465ad6 100644
--- a/hw/riscv/Kconfig
+++ b/hw/riscv/Kconfig
@@ -163,3 +163,4 @@ config K230
     select UNIMP
     select K230_WDT
     select DW_SSI
+    select SSI_M25P80
diff --git a/hw/riscv/k230.c b/hw/riscv/k230.c
index d856864839..5dd49a6752 100644
--- a/hw/riscv/k230.c
+++ b/hw/riscv/k230.c
@@ -33,6 +33,7 @@
 #include "hw/intc/sifive_plic.h"
 #include "hw/char/serial-mm.h"
 #include "hw/misc/unimp.h"
+#include "hw/ssi/ssi.h"
 
 /* Align K230_SDK k230_canmv_defconfig */
 #define K230_DIRECT_OPENSBI_ADDR 0x8000000
@@ -543,6 +544,49 @@ static void k230_firmware_boot(K230MachineState *s, MachineState *machine)
                               memmap[K230_DEV_BOOTROM].size, 0, 0);
 }
 
+static char *k230_machine_get_spi_flash(Object *obj, Error **errp)
+{
+    K230MachineState *s = RISCV_K230_MACHINE(obj);
+
+    return g_strdup(s->spi_flash_model);
+}
+
+static void k230_machine_set_spi_flash(Object *obj, const char *value,
+                                       Error **errp)
+{
+    K230MachineState *s = RISCV_K230_MACHINE(obj);
+
+    g_free(s->spi_flash_model);
+    s->spi_flash_model = g_strdup(value);
+}
+
+static void k230_connect_spi_flash(DwSsiState *ssi, unsigned int cs,
+                                   const char *flash_type, DriveInfo *dinfo)
+{
+    ObjectClass *flash_class;
+    DeviceState *flash;
+    qemu_irq flash_cs;
+
+    flash_class = module_object_class_by_name(flash_type);
+    if (!flash_class || object_class_is_abstract(flash_class) ||
+        !object_class_dynamic_cast(flash_class, TYPE_M25P80)) {
+        error_report("'%s' is either abstract or not a subtype of m25p80",
+                     flash_type);
+        exit(EXIT_FAILURE);
+    }
+
+    flash = qdev_new(flash_type);
+
+    if (dinfo) {
+        qdev_prop_set_drive(flash, "drive", blk_by_legacy_dinfo(dinfo));
+    }
+
+    qdev_realize_and_unref(flash, BUS(ssi->spi), &error_fatal);
+
+    flash_cs = qdev_get_gpio_in_named(flash, SSI_GPIO_CS, 0);
+    qdev_connect_gpio_out_named(DEVICE(ssi), "cs", cs, flash_cs);
+}
+
 static void k230_machine_done(Notifier *notifier, void *data)
 {
     K230MachineState *s = container_of(notifier, K230MachineState,
@@ -574,6 +618,12 @@ static void k230_machine_init(MachineState *machine)
                             TYPE_RISCV_K230_SOC);
     qdev_realize(DEVICE(&s->soc), NULL, &error_fatal);
 
+    if (s->spi_flash_model) {
+        k230_connect_spi_flash(&s->soc.dw_ssi[2], 0,
+                               s->spi_flash_model,
+                               drive_get(IF_MTD, 0, 0));
+    }
+
     /* Data Memory */
     memory_region_add_subregion(sys_mem, memmap[K230_DEV_DDRC].base,
                                 machine->ram);
@@ -586,6 +636,13 @@ static void k230_machine_instance_init(Object *obj)
 {
 }
 
+static void k230_machine_instance_finalize(Object *obj)
+{
+    K230MachineState *s = RISCV_K230_MACHINE(obj);
+
+    g_clear_pointer(&s->spi_flash_model, g_free);
+}
+
 static void k230_machine_class_init(ObjectClass *oc, const void *data)
 {
     MachineClass *mc = MACHINE_CLASS(oc);
@@ -596,6 +653,11 @@ static void k230_machine_class_init(ObjectClass *oc, const void *data)
     mc->default_ram_id = "riscv.K230.ram"; /* DDR */
     mc->default_ram_size = memmap[K230_DEV_DDRC].size;
 
+    object_class_property_add_str(oc, "spi-flash",
+                                  k230_machine_get_spi_flash,
+                                  k230_machine_set_spi_flash);
+    object_class_property_set_description(
+        oc, "spi-flash", "Attach an M25P80-compatible flash to spi0 CS0");
 }
 
 static const TypeInfo k230_machine_typeinfo = {
@@ -603,6 +665,7 @@ static const TypeInfo k230_machine_typeinfo = {
     .parent     = TYPE_MACHINE,
     .class_init = k230_machine_class_init,
     .instance_init = k230_machine_instance_init,
+    .instance_finalize = k230_machine_instance_finalize,
     .instance_size = sizeof(K230MachineState),
     .interfaces = riscv64_machine_interfaces,
 };
diff --git a/include/hw/riscv/k230.h b/include/hw/riscv/k230.h
index 275b6b62c3..80fb4c0e69 100644
--- a/include/hw/riscv/k230.h
+++ b/include/hw/riscv/k230.h
@@ -52,6 +52,8 @@ typedef struct K230MachineState {
     /*< public >*/
     K230SoCState soc;
     Notifier machine_done;
+
+    char *spi_flash_model;
 } K230MachineState;
 
 enum {
diff --git a/tests/qtest/k230-dw-ssi-test.c b/tests/qtest/k230-dw-ssi-test.c
index 7252302c0e..f381be14b5 100644
--- a/tests/qtest/k230-dw-ssi-test.c
+++ b/tests/qtest/k230-dw-ssi-test.c
@@ -474,6 +474,59 @@ static void test_icr_total_clear(void)
     qtest_quit(qts);
 }
 
+static void test_flash_jedec_id(void)
+{
+    QTestState *qts = qtest_init("-machine k230,spi-flash=m25p80");
+    uint32_t id;
+
+    k230_ssi_configure(qts, K230_SPI0_BASE, K230_SSI_TMOD_TR, 8, 0);
+    k230_ssi_enable_cs(qts, K230_SPI0_BASE, BIT(0));
+
+    /* JEDEC RDID (0x9f): m25p80 reports 0x20 0x20 0x14. */
+    k230_ssi_write_frame(qts, K230_SPI0_BASE, 0x9f);
+    (void)k230_ssi_read_frame(qts, K230_SPI0_BASE);
+    k230_ssi_write_frame(qts, K230_SPI0_BASE, 0x00);
+    id = k230_ssi_read_frame(qts, K230_SPI0_BASE);
+    g_assert_cmphex(id & 0xff, ==, 0x20);
+    k230_ssi_write_frame(qts, K230_SPI0_BASE, 0x00);
+    id = k230_ssi_read_frame(qts, K230_SPI0_BASE);
+    g_assert_cmphex(id & 0xff, ==, 0x20);
+    k230_ssi_write_frame(qts, K230_SPI0_BASE, 0x00);
+    id = k230_ssi_read_frame(qts, K230_SPI0_BASE);
+    g_assert_cmphex(id & 0xff, ==, 0x14);
+
+    qtest_quit(qts);
+}
+
+static void test_flash_fixed_read(void)
+{
+    QTestState *qts = qtest_init("-machine k230,spi-flash=m25p80");
+    uint32_t byte;
+
+    k230_ssi_configure(qts, K230_SPI0_BASE, K230_SSI_TMOD_TR, 8, 0);
+    k230_ssi_enable_cs(qts, K230_SPI0_BASE, BIT(0));
+
+    /* Standard 1-1-1 READ (0x03) at address 0x000000. */
+    k230_ssi_write_frame(qts, K230_SPI0_BASE, 0x03);
+    (void)k230_ssi_read_frame(qts, K230_SPI0_BASE);
+    k230_ssi_write_frame(qts, K230_SPI0_BASE, 0x00);
+    (void)k230_ssi_read_frame(qts, K230_SPI0_BASE);
+    k230_ssi_write_frame(qts, K230_SPI0_BASE, 0x00);
+    (void)k230_ssi_read_frame(qts, K230_SPI0_BASE);
+    k230_ssi_write_frame(qts, K230_SPI0_BASE, 0x00);
+    (void)k230_ssi_read_frame(qts, K230_SPI0_BASE);
+
+    /* Without a backend the flash is erased and reads back 0xff. */
+    k230_ssi_write_frame(qts, K230_SPI0_BASE, 0x00);
+    byte = k230_ssi_read_frame(qts, K230_SPI0_BASE);
+    g_assert_cmphex(byte & 0xff, ==, 0xff);
+    k230_ssi_write_frame(qts, K230_SPI0_BASE, 0x00);
+    byte = k230_ssi_read_frame(qts, K230_SPI0_BASE);
+    g_assert_cmphex(byte & 0xff, ==, 0xff);
+
+    qtest_quit(qts);
+}
+
 static void test_unsupported_registers(void)
 {
     QTestState *qts = k230_ssi_start();
@@ -510,5 +563,7 @@ int main(int argc, char **argv)
     qtest_add_func("/k230-dw-ssi/icr-total-clear", test_icr_total_clear);
     qtest_add_func("/k230-dw-ssi/unsupported-registers",
                    test_unsupported_registers);
+    qtest_add_func("/k230-dw-ssi/flash-jedec-id", test_flash_jedec_id);
+    qtest_add_func("/k230-dw-ssi/flash-fixed-read", test_flash_fixed_read);
     return g_test_run();
 }
-- 
2.43.0