hw/riscv/atlantis: Add some i2c peripherals

Add an I2C RTC device and a temperature sensor. These are not present
on the board but help for testing.

The tmp105 is a lm75 compatible temperature sensor used by the
SENSORS_LM75 Linux kernel driver.

The ds1338 is a RTC device that is used by the RTC_DRV_DS1307 Linux
kernel driver.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Message-ID: <20260630024952.1520546-13-joel@jms.id.au>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

2 files changed, 29 insertions, 0 deletions

diff --git a/hw/riscv/Kconfig b/hw/riscv/Kconfig
index dcce819bf6..de37c08cae 100644
--- a/hw/riscv/Kconfig
+++ b/hw/riscv/Kconfig
@@ -130,6 +130,8 @@ config TENSTORRENT
     select SERIAL_MM
     select DEVICE_TREE
     select DESIGNWARE_I2C
+    select DS1338
+    select TMP105
 
 config XIANGSHAN_KUNMINGHU
     bool
diff --git a/hw/riscv/tt_atlantis.c b/hw/riscv/tt_atlantis.c
index 5ce150fff7..beaf64e0c1 100644
--- a/hw/riscv/tt_atlantis.c
+++ b/hw/riscv/tt_atlantis.c
@@ -64,6 +64,13 @@ static const MemMapEntry tt_atlantis_memmap[] = {
     [TT_ATL_DDR_HI] =          { 0x100000000,  0x1000000000 },
 };
 
+static I2CBus *i2c_get_bus(TTAtlantisState *s, unsigned busnr)
+{
+    assert(busnr < TT_ATL_NUM_I2C);
+
+    return s->i2c[busnr].bus;
+}
+
 static uint32_t fdt_phandle = 1;
 static uint32_t next_phandle(void)
 {
@@ -309,6 +316,19 @@ static void create_fdt_i2c(void *fdt, const MemMapEntry *mem, uint32_t irq,
     qemu_fdt_setprop_cell(fdt, name, "#size-cells", 0);
 }
 
+static void create_fdt_i2c_device(TTAtlantisState *s, int bus,
+                                  const char *compat, int addr)
+{
+    void *fdt = MACHINE(s)->fdt;
+    hwaddr base = s->memmap[TT_ATL_I2C0 + bus].base;
+    g_autofree char *name = g_strdup_printf("/soc/i2c@%"HWADDR_PRIX"/sensor@%x",
+                                            base, addr);
+
+    qemu_fdt_add_subnode(fdt, name);
+    qemu_fdt_setprop_string(fdt, name, "compatible", compat);
+    qemu_fdt_setprop_cell(fdt, name, "reg", addr);
+}
+
 static void finalize_fdt(TTAtlantisState *s)
 {
     uint32_t aplic_s_phandle = next_phandle();
@@ -336,6 +356,9 @@ static void finalize_fdt(TTAtlantisState *s)
                        TT_ATL_I2C0_IRQ + i,
                        aplic_s_phandle, periph_clk_phandle);
     }
+
+    create_fdt_i2c_device(s, 0, "dallas,ds1338", 0x6f);
+    create_fdt_i2c_device(s, 4, "ti,tmp105", 0x48);
 }
 
 static void create_fdt(TTAtlantisState *s)
@@ -551,6 +574,10 @@ static void tt_atlantis_machine_init(MachineState *machine)
                            qdev_get_gpio_in(s->irqchip, TT_ATL_I2C0_IRQ + i));
     }
 
+    /* I2C peripherals: qemu specific */
+    i2c_slave_create_simple(i2c_get_bus(s, 0), "ds1338", 0x6f);
+    i2c_slave_create_simple(i2c_get_bus(s, 4), "tmp105", 0x48);
+
     /* Load or create device tree */
     if (machine->dtb) {
         load_fdt(s);