hw/misc/max111x: Create header file for documentation, TYPE_ macros

Create a header file for the hw/misc/max111x device, in the
usual modern style for QOM devices:
 * definition of the TYPE_ constants and macros
 * definition of the device's state struct so that it can
   be embedded in other structs if desired
 * documentation of the interface

This allows us to use TYPE_MAX_1111 in the spitz.c code rather
than the string "max1111".

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20200628142429.17111-12-peter.maydell@linaro.org

MAINTAINERS

@@ -787,6 +787,7 @@ F: hw/gpio/max7310.c
 F: hw/gpio/zaurus.c
 F: hw/misc/mst_fpga.c
 F: hw/misc/max111x.c
+F: include/hw/misc/max111x.h
 F: include/hw/arm/pxa.h
 F: include/hw/arm/sharpsl.h
 F: include/hw/display/tc6393xb.h

hw/arm/spitz.c

@@ -29,6 +29,7 @@
 #include "audio/audio.h"
 #include "hw/boards.h"
 #include "hw/sysbus.h"
+#include "hw/misc/max111x.h"
 #include "migration/vmstate.h"
 #include "exec/address-spaces.h"
 #include "cpu.h"
@@ -732,7 +733,7 @@ static void spitz_ssp_attach(SpitzMachineState *sms)
                           qdev_get_gpio_in(sms->mpu->gpio, SPITZ_GPIO_TP_INT));
 
     bus = qdev_get_child_bus(sms->mux, "ssi2");
-    sms->max1111 = qdev_new("max1111");
+    sms->max1111 = qdev_new(TYPE_MAX_1111);
     max1111 = sms->max1111;
     qdev_prop_set_uint8(sms->max1111, "input1" /* BATT_VOLT */,
                         SPITZ_BATTERY_VOLT);

hw/misc/max111x.c

@@ -11,34 +11,12 @@
  */
 
 #include "qemu/osdep.h"
+#include "hw/misc/max111x.h"
 #include "hw/irq.h"
-#include "hw/ssi/ssi.h"
 #include "migration/vmstate.h"
 #include "qemu/module.h"
 #include "hw/qdev-properties.h"
 
-typedef struct {
-    SSISlave parent_obj;
-
-    qemu_irq interrupt;
-    /* Values of inputs at system reset (settable by QOM property) */
-    uint8_t reset_input[8];
-
-    uint8_t tb1, rb2, rb3;
-    int cycle;
-
-    uint8_t input[8];
-    int inputs, com;
-} MAX111xState;
-
-#define TYPE_MAX_111X "max111x"
-
-#define MAX_111X(obj) \
-    OBJECT_CHECK(MAX111xState, (obj), TYPE_MAX_111X)
-
-#define TYPE_MAX_1110 "max1110"
-#define TYPE_MAX_1111 "max1111"
-
 /* Control-byte bitfields */
 #define CB_PD0		(1 << 0)
 #define CB_PD1		(1 << 1)

include/hw/misc/max111x.h

@@ -0,0 +1,56 @@
+/*
+ * Maxim MAX1110/1111 ADC chip emulation.
+ *
+ * Copyright (c) 2006 Openedhand Ltd.
+ * Written by Andrzej Zaborowski <balrog@zabor.org>
+ *
+ * This code is licensed under the GNU GPLv2.
+ *
+ * Contributions after 2012-01-13 are licensed under the terms of the
+ * GNU GPL, version 2 or (at your option) any later version.
+ */
+
+#ifndef HW_MISC_MAX111X_H
+#define HW_MISC_MAX111X_H
+
+#include "hw/ssi/ssi.h"
+
+/*
+ * This is a model of the Maxim MAX1110/1111 ADC chip, which for QEMU
+ * is an SSI slave device. It has either 4 (max1110) or 8 (max1111)
+ * 8-bit ADC channels.
+ *
+ * QEMU interface:
+ *  + GPIO inputs 0..3 (for max1110) or 0..7 (for max1111): set the value
+ *    of each ADC input, as an unsigned 8-bit value
+ *  + GPIO output 0: interrupt line
+ *  + Properties "input0" to "input3" (max1110) or "input0" to "input7"
+ *    (max1111): initial reset values for ADC inputs.
+ *
+ * Known bugs:
+ *  + the interrupt line is not correctly implemented, and will never
+ *    be lowered once it has been asserted.
+ */
+typedef struct {
+    SSISlave parent_obj;
+
+    qemu_irq interrupt;
+    /* Values of inputs at system reset (settable by QOM property) */
+    uint8_t reset_input[8];
+
+    uint8_t tb1, rb2, rb3;
+    int cycle;
+
+    uint8_t input[8];
+    int inputs, com;
+} MAX111xState;
+
+#define TYPE_MAX_111X "max111x"
+
+#define MAX_111X(obj) \
+    OBJECT_CHECK(MAX111xState, (obj), TYPE_MAX_111X)
+
+#define TYPE_MAX_1110 "max1110"
+#define TYPE_MAX_1111 "max1111"
+
+#endif