ads7846: moves from the hw/display folder to the hw/input folder.

ads7846 is a touch-screen controller that is an input device rather
than a display device, so move it to the hw/input folder.

Signed-off-by: Gan Qixin <ganqixin@huawei.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20201115123503.1110665-1-ganqixin@huawei.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

3 files changed, 190 insertions, 0 deletions

diff --git a/hw/input/Kconfig b/hw/input/Kconfig
index 64f14daabf..55865bb386 100644
--- a/hw/input/Kconfig
+++ b/hw/input/Kconfig
@@ -1,6 +1,9 @@
 config ADB
     bool
 
+config ADS7846
+    bool
+
 config LM832X
     bool
     depends on I2C
diff --git a/hw/input/ads7846.c b/hw/input/ads7846.c
new file mode 100644
index 0000000000..1d4e04a2dc
--- /dev/null
+++ b/hw/input/ads7846.c
@@ -0,0 +1,186 @@
+/*
+ * TI ADS7846 / TSC2046 chip emulation.
+ *
+ * Copyright (c) 2006 Openedhand Ltd.
+ * Written by Andrzej Zaborowski <balrog@zabor.org>
+ *
+ * This code is licensed under the GNU GPL v2.
+ *
+ * Contributions after 2012-01-13 are licensed under the terms of the
+ * GNU GPL, version 2 or (at your option) any later version.
+ */
+
+#include "qemu/osdep.h"
+#include "hw/irq.h"
+#include "hw/ssi/ssi.h"
+#include "migration/vmstate.h"
+#include "qemu/module.h"
+#include "ui/console.h"
+#include "qom/object.h"
+
+struct ADS7846State {
+    SSIPeripheral ssidev;
+    qemu_irq interrupt;
+
+    int input[8];
+    int pressure;
+    int noise;
+
+    int cycle;
+    int output;
+};
+
+#define TYPE_ADS7846 "ads7846"
+OBJECT_DECLARE_SIMPLE_TYPE(ADS7846State, ADS7846)
+
+/* Control-byte bitfields */
+#define CB_PD0		(1 << 0)
+#define CB_PD1		(1 << 1)
+#define CB_SER		(1 << 2)
+#define CB_MODE		(1 << 3)
+#define CB_A0		(1 << 4)
+#define CB_A1		(1 << 5)
+#define CB_A2		(1 << 6)
+#define CB_START	(1 << 7)
+
+#define X_AXIS_DMAX	3470
+#define X_AXIS_MIN	290
+#define Y_AXIS_DMAX	3450
+#define Y_AXIS_MIN	200
+
+#define ADS_VBAT	2000
+#define ADS_VAUX	2000
+#define ADS_TEMP0	2000
+#define ADS_TEMP1	3000
+#define ADS_XPOS(x, y)	(X_AXIS_MIN + ((X_AXIS_DMAX * (x)) >> 15))
+#define ADS_YPOS(x, y)	(Y_AXIS_MIN + ((Y_AXIS_DMAX * (y)) >> 15))
+#define ADS_Z1POS(x, y)	600
+#define ADS_Z2POS(x, y)	(600 + 6000 / ADS_XPOS(x, y))
+
+static void ads7846_int_update(ADS7846State *s)
+{
+    if (s->interrupt)
+        qemu_set_irq(s->interrupt, s->pressure == 0);
+}
+
+static uint32_t ads7846_transfer(SSIPeripheral *dev, uint32_t value)
+{
+    ADS7846State *s = ADS7846(dev);
+
+    switch (s->cycle ++) {
+    case 0:
+        if (!(value & CB_START)) {
+            s->cycle = 0;
+            break;
+        }
+
+        s->output = s->input[(value >> 4) & 7];
+
+        /* Imitate the ADC noise, some drivers expect this.  */
+        s->noise = (s->noise + 3) & 7;
+        switch ((value >> 4) & 7) {
+        case 1: s->output += s->noise ^ 2; break;
+        case 3: s->output += s->noise ^ 0; break;
+        case 4: s->output += s->noise ^ 7; break;
+        case 5: s->output += s->noise ^ 5; break;
+        }
+
+        if (value & CB_MODE)
+            s->output >>= 4;	/* 8 bits instead of 12 */
+
+        break;
+    case 1:
+        s->cycle = 0;
+        break;
+    }
+    return s->output;
+}
+
+static void ads7846_ts_event(void *opaque,
+                int x, int y, int z, int buttons_state)
+{
+    ADS7846State *s = opaque;
+
+    if (buttons_state) {
+        x = 0x7fff - x;
+        s->input[1] = ADS_XPOS(x, y);
+        s->input[3] = ADS_Z1POS(x, y);
+        s->input[4] = ADS_Z2POS(x, y);
+        s->input[5] = ADS_YPOS(x, y);
+    }
+
+    if (s->pressure == !buttons_state) {
+        s->pressure = !!buttons_state;
+
+        ads7846_int_update(s);
+    }
+}
+
+static int ads7856_post_load(void *opaque, int version_id)
+{
+    ADS7846State *s = opaque;
+
+    s->pressure = 0;
+    ads7846_int_update(s);
+    return 0;
+}
+
+static const VMStateDescription vmstate_ads7846 = {
+    .name = "ads7846",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .post_load = ads7856_post_load,
+    .fields = (VMStateField[]) {
+        VMSTATE_SSI_PERIPHERAL(ssidev, ADS7846State),
+        VMSTATE_INT32_ARRAY(input, ADS7846State, 8),
+        VMSTATE_INT32(noise, ADS7846State),
+        VMSTATE_INT32(cycle, ADS7846State),
+        VMSTATE_INT32(output, ADS7846State),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static void ads7846_realize(SSIPeripheral *d, Error **errp)
+{
+    DeviceState *dev = DEVICE(d);
+    ADS7846State *s = ADS7846(d);
+
+    qdev_init_gpio_out(dev, &s->interrupt, 1);
+
+    s->input[0] = ADS_TEMP0;	/* TEMP0 */
+    s->input[2] = ADS_VBAT;	/* VBAT */
+    s->input[6] = ADS_VAUX;	/* VAUX */
+    s->input[7] = ADS_TEMP1;	/* TEMP1 */
+
+    /* We want absolute coordinates */
+    qemu_add_mouse_event_handler(ads7846_ts_event, s, 1,
+                    "QEMU ADS7846-driven Touchscreen");
+
+    ads7846_int_update(s);
+
+    vmstate_register(NULL, VMSTATE_INSTANCE_ID_ANY, &vmstate_ads7846, s);
+}
+
+static void ads7846_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    SSIPeripheralClass *k = SSI_PERIPHERAL_CLASS(klass);
+
+    k->realize = ads7846_realize;
+    k->transfer = ads7846_transfer;
+    set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
+}
+
+static const TypeInfo ads7846_info = {
+    .name          = TYPE_ADS7846,
+    .parent        = TYPE_SSI_PERIPHERAL,
+    .instance_size = sizeof(ADS7846State),
+    .class_init    = ads7846_class_init,
+};
+
+static void ads7846_register_types(void)
+{
+    type_register_static(&ads7846_info);
+}
+
+type_init(ads7846_register_types)
diff --git a/hw/input/meson.build b/hw/input/meson.build
index e7285b15ae..0042c3f0dc 100644
--- a/hw/input/meson.build
+++ b/hw/input/meson.build
@@ -1,5 +1,6 @@
 softmmu_ss.add(files('hid.c'))
 softmmu_ss.add(when: 'CONFIG_ADB', if_true: files('adb.c', 'adb-mouse.c', 'adb-kbd.c'))
+softmmu_ss.add(when: 'CONFIG_ADS7846', if_true: files('ads7846.c'))
 softmmu_ss.add(when: 'CONFIG_LM832X', if_true: files('lm832x.c'))
 softmmu_ss.add(when: 'CONFIG_PCKBD', if_true: files('pckbd.c'))
 softmmu_ss.add(when: 'CONFIG_PL050', if_true: files('pl050.c'))