hw/display : Add device DM163
This device implements the IM120417002 colors shield v1.1 for Arduino
(which relies on the DM163 8x3-channel led driving logic) and features
a simple display of an 8x8 RGB matrix. The columns of the matrix are
driven by the DM163 and the rows are driven externally.
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Arnaud Minier <arnaud.minier@telecom-paris.fr>
Signed-off-by: Inès Varhol <ines.varhol@telecom-paris.fr>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-id: 20240424200929.240921-2-ines.varhol@telecom-paris.fr
[PMM: updated to new reset hold method prototype]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
diff --git a/docs/system/arm/b-l475e-iot01a.rst b/docs/system/arm/b-l475e-iot01a.rst
index a76c997..2adcc4b 100644
--- a/docs/system/arm/b-l475e-iot01a.rst
+++ b/docs/system/arm/b-l475e-iot01a.rst
@@ -12,7 +12,7 @@
Supported devices
"""""""""""""""""
-Currently B-L475E-IOT01A machine's only supports the following devices:
+Currently B-L475E-IOT01A machines support the following devices:
- Cortex-M4F based STM32L4x5 SoC
- STM32L4x5 EXTI (Extended interrupts and events controller)
@@ -20,6 +20,7 @@
- STM32L4x5 RCC (Reset and clock control)
- STM32L4x5 GPIOs (General-purpose I/Os)
- STM32L4x5 USARTs, UARTs and LPUART (Serial ports)
+- optional 8x8 led display (based on DM163 driver)
Missing devices
"""""""""""""""
diff --git a/hw/display/Kconfig b/hw/display/Kconfig
index 234c7de..a4552c8 100644
--- a/hw/display/Kconfig
+++ b/hw/display/Kconfig
@@ -140,3 +140,6 @@
bool
# defaults to "N", enabled by specific boards
depends on PIXMAN
+
+config DM163
+ bool
diff --git a/hw/display/dm163.c b/hw/display/dm163.c
new file mode 100644
index 0000000..f92aee3
--- /dev/null
+++ b/hw/display/dm163.c
@@ -0,0 +1,349 @@
+/*
+ * QEMU DM163 8x3-channel constant current led driver
+ * driving columns of associated 8x8 RGB matrix.
+ *
+ * Copyright (C) 2024 Samuel Tardieu <sam@rfc1149.net>
+ * Copyright (C) 2024 Arnaud Minier <arnaud.minier@telecom-paris.fr>
+ * Copyright (C) 2024 Inès Varhol <ines.varhol@telecom-paris.fr>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+/*
+ * The reference used for the DM163 is the following :
+ * http://www.siti.com.tw/product/spec/LED/DM163.pdf
+ */
+
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "migration/vmstate.h"
+#include "hw/irq.h"
+#include "hw/qdev-properties.h"
+#include "hw/display/dm163.h"
+#include "ui/console.h"
+#include "trace.h"
+
+#define LED_SQUARE_SIZE 100
+/* Number of frames a row stays visible after being turned off. */
+#define ROW_PERSISTENCE 3
+#define TURNED_OFF_ROW (COLOR_BUFFER_SIZE - 1)
+
+static const VMStateDescription vmstate_dm163 = {
+ .name = TYPE_DM163,
+ .version_id = 1,
+ .minimum_version_id = 1,
+ .fields = (const VMStateField[]) {
+ VMSTATE_UINT64_ARRAY(bank0_shift_register, DM163State, 3),
+ VMSTATE_UINT64_ARRAY(bank1_shift_register, DM163State, 3),
+ VMSTATE_UINT16_ARRAY(latched_outputs, DM163State, DM163_NUM_LEDS),
+ VMSTATE_UINT16_ARRAY(outputs, DM163State, DM163_NUM_LEDS),
+ VMSTATE_UINT8(dck, DM163State),
+ VMSTATE_UINT8(en_b, DM163State),
+ VMSTATE_UINT8(lat_b, DM163State),
+ VMSTATE_UINT8(rst_b, DM163State),
+ VMSTATE_UINT8(selbk, DM163State),
+ VMSTATE_UINT8(sin, DM163State),
+ VMSTATE_UINT8(activated_rows, DM163State),
+ VMSTATE_UINT32_2DARRAY(buffer, DM163State, COLOR_BUFFER_SIZE,
+ RGB_MATRIX_NUM_COLS),
+ VMSTATE_UINT8(last_buffer_idx, DM163State),
+ VMSTATE_UINT8_ARRAY(buffer_idx_of_row, DM163State, RGB_MATRIX_NUM_ROWS),
+ VMSTATE_UINT8_ARRAY(row_persistence_delay, DM163State,
+ RGB_MATRIX_NUM_ROWS),
+ VMSTATE_END_OF_LIST()
+ }
+};
+
+static void dm163_reset_hold(Object *obj, ResetType type)
+{
+ DM163State *s = DM163(obj);
+
+ s->sin = 0;
+ s->dck = 0;
+ s->rst_b = 0;
+ /* Ensuring the first falling edge of lat_b isn't missed */
+ s->lat_b = 1;
+ s->selbk = 0;
+ s->en_b = 0;
+ /* Reset stops the PWM, not the shift and latched registers. */
+ memset(s->outputs, 0, sizeof(s->outputs));
+
+ s->activated_rows = 0;
+ s->redraw = 0;
+ trace_dm163_redraw(s->redraw);
+ for (unsigned i = 0; i < COLOR_BUFFER_SIZE; i++) {
+ memset(s->buffer[i], 0, sizeof(s->buffer[0]));
+ }
+ s->last_buffer_idx = 0;
+ memset(s->buffer_idx_of_row, TURNED_OFF_ROW, sizeof(s->buffer_idx_of_row));
+ memset(s->row_persistence_delay, 0, sizeof(s->row_persistence_delay));
+}
+
+static void dm163_dck_gpio_handler(void *opaque, int line, int new_state)
+{
+ DM163State *s = opaque;
+
+ if (new_state && !s->dck) {
+ /*
+ * On raising dck, sample selbk to get the bank to use, and
+ * sample sin for the bit to enter into the bank shift buffer.
+ */
+ uint64_t *sb =
+ s->selbk ? s->bank1_shift_register : s->bank0_shift_register;
+ /* Output the outgoing bit on sout */
+ const bool sout = (s->selbk ? sb[2] & MAKE_64BIT_MASK(63, 1) :
+ sb[2] & MAKE_64BIT_MASK(15, 1)) != 0;
+ qemu_set_irq(s->sout, sout);
+ /* Enter sin into the shift buffer */
+ sb[2] = (sb[2] << 1) | ((sb[1] >> 63) & 1);
+ sb[1] = (sb[1] << 1) | ((sb[0] >> 63) & 1);
+ sb[0] = (sb[0] << 1) | s->sin;
+ }
+
+ s->dck = new_state;
+ trace_dm163_dck(new_state);
+}
+
+static void dm163_propagate_outputs(DM163State *s)
+{
+ s->last_buffer_idx = (s->last_buffer_idx + 1) % RGB_MATRIX_NUM_ROWS;
+ /* Values are output when reset is high and enable is low. */
+ if (s->rst_b && !s->en_b) {
+ memcpy(s->outputs, s->latched_outputs, sizeof(s->outputs));
+ } else {
+ memset(s->outputs, 0, sizeof(s->outputs));
+ }
+ for (unsigned x = 0; x < RGB_MATRIX_NUM_COLS; x++) {
+ /* Grouping the 3 RGB channels in a pixel value */
+ const uint16_t b = extract16(s->outputs[3 * x + 0], 6, 8);
+ const uint16_t g = extract16(s->outputs[3 * x + 1], 6, 8);
+ const uint16_t r = extract16(s->outputs[3 * x + 2], 6, 8);
+ uint32_t rgba = 0;
+
+ trace_dm163_channels(3 * x + 2, r);
+ trace_dm163_channels(3 * x + 1, g);
+ trace_dm163_channels(3 * x + 0, b);
+
+ rgba = deposit32(rgba, 0, 8, r);
+ rgba = deposit32(rgba, 8, 8, g);
+ rgba = deposit32(rgba, 16, 8, b);
+
+ /* Led values are sent from the last one to the first one */
+ s->buffer[s->last_buffer_idx][RGB_MATRIX_NUM_COLS - x - 1] = rgba;
+ }
+ for (unsigned row = 0; row < RGB_MATRIX_NUM_ROWS; row++) {
+ if (s->activated_rows & (1 << row)) {
+ s->buffer_idx_of_row[row] = s->last_buffer_idx;
+ s->redraw |= (1 << row);
+ trace_dm163_redraw(s->redraw);
+ }
+ }
+}
+
+static void dm163_en_b_gpio_handler(void *opaque, int line, int new_state)
+{
+ DM163State *s = opaque;
+
+ s->en_b = new_state;
+ dm163_propagate_outputs(s);
+ trace_dm163_en_b(new_state);
+}
+
+static uint8_t dm163_bank0(const DM163State *s, uint8_t led)
+{
+ /*
+ * Bank 0 uses 6 bits per led, so a value may be stored accross
+ * two uint64_t entries.
+ */
+ const uint8_t low_bit = 6 * led;
+ const uint8_t low_word = low_bit / 64;
+ const uint8_t high_word = (low_bit + 5) / 64;
+ const uint8_t low_shift = low_bit % 64;
+
+ if (low_word == high_word) {
+ /* Simple case: the value belongs to one entry. */
+ return extract64(s->bank0_shift_register[low_word], low_shift, 6);
+ }
+
+ const uint8_t nb_bits_in_low_word = 64 - low_shift;
+ const uint8_t nb_bits_in_high_word = 6 - nb_bits_in_low_word;
+
+ const uint64_t bits_in_low_word = \
+ extract64(s->bank0_shift_register[low_word], low_shift,
+ nb_bits_in_low_word);
+ const uint64_t bits_in_high_word = \
+ extract64(s->bank0_shift_register[high_word], 0,
+ nb_bits_in_high_word);
+ uint8_t val = 0;
+
+ val = deposit32(val, 0, nb_bits_in_low_word, bits_in_low_word);
+ val = deposit32(val, nb_bits_in_low_word, nb_bits_in_high_word,
+ bits_in_high_word);
+
+ return val;
+}
+
+static uint8_t dm163_bank1(const DM163State *s, uint8_t led)
+{
+ const uint64_t entry = s->bank1_shift_register[led / RGB_MATRIX_NUM_COLS];
+ return extract64(entry, 8 * (led % RGB_MATRIX_NUM_COLS), 8);
+}
+
+static void dm163_lat_b_gpio_handler(void *opaque, int line, int new_state)
+{
+ DM163State *s = opaque;
+
+ if (s->lat_b && !new_state) {
+ for (int led = 0; led < DM163_NUM_LEDS; led++) {
+ s->latched_outputs[led] = dm163_bank0(s, led) * dm163_bank1(s, led);
+ }
+ dm163_propagate_outputs(s);
+ }
+
+ s->lat_b = new_state;
+ trace_dm163_lat_b(new_state);
+}
+
+static void dm163_rst_b_gpio_handler(void *opaque, int line, int new_state)
+{
+ DM163State *s = opaque;
+
+ s->rst_b = new_state;
+ dm163_propagate_outputs(s);
+ trace_dm163_rst_b(new_state);
+}
+
+static void dm163_selbk_gpio_handler(void *opaque, int line, int new_state)
+{
+ DM163State *s = opaque;
+
+ s->selbk = new_state;
+ trace_dm163_selbk(new_state);
+}
+
+static void dm163_sin_gpio_handler(void *opaque, int line, int new_state)
+{
+ DM163State *s = opaque;
+
+ s->sin = new_state;
+ trace_dm163_sin(new_state);
+}
+
+static void dm163_rows_gpio_handler(void *opaque, int line, int new_state)
+{
+ DM163State *s = opaque;
+
+ if (new_state) {
+ s->activated_rows |= (1 << line);
+ s->buffer_idx_of_row[line] = s->last_buffer_idx;
+ s->redraw |= (1 << line);
+ trace_dm163_redraw(s->redraw);
+ } else {
+ s->activated_rows &= ~(1 << line);
+ s->row_persistence_delay[line] = ROW_PERSISTENCE;
+ }
+ trace_dm163_activated_rows(s->activated_rows);
+}
+
+static void dm163_invalidate_display(void *opaque)
+{
+ DM163State *s = (DM163State *)opaque;
+ s->redraw = 0xFF;
+ trace_dm163_redraw(s->redraw);
+}
+
+static void update_row_persistence_delay(DM163State *s, unsigned row)
+{
+ if (s->row_persistence_delay[row]) {
+ s->row_persistence_delay[row]--;
+ } else {
+ /*
+ * If the ROW_PERSISTENCE delay is up,
+ * the row is turned off.
+ */
+ s->buffer_idx_of_row[row] = TURNED_OFF_ROW;
+ s->redraw |= (1 << row);
+ trace_dm163_redraw(s->redraw);
+ }
+}
+
+static uint32_t *update_display_of_row(DM163State *s, uint32_t *dest,
+ unsigned row)
+{
+ for (unsigned _ = 0; _ < LED_SQUARE_SIZE; _++) {
+ for (int x = 0; x < RGB_MATRIX_NUM_COLS * LED_SQUARE_SIZE; x++) {
+ /* UI layer guarantees that there's 32 bits per pixel (Mar 2024) */
+ *dest++ = s->buffer[s->buffer_idx_of_row[row]][x / LED_SQUARE_SIZE];
+ }
+ }
+
+ dpy_gfx_update(s->console, 0, LED_SQUARE_SIZE * row,
+ RGB_MATRIX_NUM_COLS * LED_SQUARE_SIZE, LED_SQUARE_SIZE);
+ s->redraw &= ~(1 << row);
+ trace_dm163_redraw(s->redraw);
+
+ return dest;
+}
+
+static void dm163_update_display(void *opaque)
+{
+ DM163State *s = (DM163State *)opaque;
+ DisplaySurface *surface = qemu_console_surface(s->console);
+ uint32_t *dest;
+
+ dest = surface_data(surface);
+ for (unsigned row = 0; row < RGB_MATRIX_NUM_ROWS; row++) {
+ update_row_persistence_delay(s, row);
+ if (!extract8(s->redraw, row, 1)) {
+ dest += LED_SQUARE_SIZE * LED_SQUARE_SIZE * RGB_MATRIX_NUM_COLS;
+ continue;
+ }
+ dest = update_display_of_row(s, dest, row);
+ }
+}
+
+static const GraphicHwOps dm163_ops = {
+ .invalidate = dm163_invalidate_display,
+ .gfx_update = dm163_update_display,
+};
+
+static void dm163_realize(DeviceState *dev, Error **errp)
+{
+ DM163State *s = DM163(dev);
+
+ qdev_init_gpio_in(dev, dm163_rows_gpio_handler, RGB_MATRIX_NUM_ROWS);
+ qdev_init_gpio_in(dev, dm163_sin_gpio_handler, 1);
+ qdev_init_gpio_in(dev, dm163_dck_gpio_handler, 1);
+ qdev_init_gpio_in(dev, dm163_rst_b_gpio_handler, 1);
+ qdev_init_gpio_in(dev, dm163_lat_b_gpio_handler, 1);
+ qdev_init_gpio_in(dev, dm163_selbk_gpio_handler, 1);
+ qdev_init_gpio_in(dev, dm163_en_b_gpio_handler, 1);
+ qdev_init_gpio_out_named(dev, &s->sout, "sout", 1);
+
+ s->console = graphic_console_init(dev, 0, &dm163_ops, s);
+ qemu_console_resize(s->console, RGB_MATRIX_NUM_COLS * LED_SQUARE_SIZE,
+ RGB_MATRIX_NUM_ROWS * LED_SQUARE_SIZE);
+}
+
+static void dm163_class_init(ObjectClass *klass, void *data)
+{
+ DeviceClass *dc = DEVICE_CLASS(klass);
+ ResettableClass *rc = RESETTABLE_CLASS(klass);
+
+ dc->desc = "DM163";
+ dc->vmsd = &vmstate_dm163;
+ dc->realize = dm163_realize;
+ rc->phases.hold = dm163_reset_hold;
+ set_bit(DEVICE_CATEGORY_DISPLAY, dc->categories);
+}
+
+static const TypeInfo dm163_types[] = {
+ {
+ .name = TYPE_DM163,
+ .parent = TYPE_DEVICE,
+ .instance_size = sizeof(DM163State),
+ .class_init = dm163_class_init
+ }
+};
+
+DEFINE_TYPES(dm163_types)
diff --git a/hw/display/meson.build b/hw/display/meson.build
index 4751aab..7893b94 100644
--- a/hw/display/meson.build
+++ b/hw/display/meson.build
@@ -38,6 +38,7 @@
system_ss.add(when: 'CONFIG_VGA', if_true: files('vga.c'))
system_ss.add(when: 'CONFIG_VIRTIO', if_true: files('virtio-dmabuf.c'))
+system_ss.add(when: 'CONFIG_DM163', if_true: files('dm163.c'))
if (config_all_devices.has_key('CONFIG_VGA_CIRRUS') or
config_all_devices.has_key('CONFIG_VGA_PCI') or
diff --git a/hw/display/trace-events b/hw/display/trace-events
index 2336a0c..781f8a3 100644
--- a/hw/display/trace-events
+++ b/hw/display/trace-events
@@ -177,3 +177,17 @@
macfb_sense_read(uint32_t value) "video sense: 0x%"PRIx32
macfb_sense_write(uint32_t value) "video sense: 0x%"PRIx32
macfb_update_mode(uint32_t width, uint32_t height, uint8_t depth) "setting mode to width %"PRId32 " height %"PRId32 " size %d"
+
+# dm163.c
+dm163_redraw(uint8_t redraw) "0x%02x"
+dm163_dck(unsigned new_state) "dck : %u"
+dm163_en_b(unsigned new_state) "en_b : %u"
+dm163_rst_b(unsigned new_state) "rst_b : %u"
+dm163_lat_b(unsigned new_state) "lat_b : %u"
+dm163_sin(unsigned new_state) "sin : %u"
+dm163_selbk(unsigned new_state) "selbk : %u"
+dm163_activated_rows(int new_state) "Activated rows : 0x%" PRIx32 ""
+dm163_bits_ppi(unsigned dest_width) "dest_width : %u"
+dm163_leds(int led, uint32_t value) "led %d: 0x%x"
+dm163_channels(int channel, uint8_t value) "channel %d: 0x%x"
+dm163_refresh_rate(uint32_t rr) "refresh rate %d"
diff --git a/include/hw/display/dm163.h b/include/hw/display/dm163.h
new file mode 100644
index 0000000..4377f77
--- /dev/null
+++ b/include/hw/display/dm163.h
@@ -0,0 +1,59 @@
+/*
+ * QEMU DM163 8x3-channel constant current led driver
+ * driving columns of associated 8x8 RGB matrix.
+ *
+ * Copyright (C) 2024 Samuel Tardieu <sam@rfc1149.net>
+ * Copyright (C) 2024 Arnaud Minier <arnaud.minier@telecom-paris.fr>
+ * Copyright (C) 2024 Inès Varhol <ines.varhol@telecom-paris.fr>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef HW_DISPLAY_DM163_H
+#define HW_DISPLAY_DM163_H
+
+#include "qom/object.h"
+#include "hw/qdev-core.h"
+
+#define TYPE_DM163 "dm163"
+OBJECT_DECLARE_SIMPLE_TYPE(DM163State, DM163);
+
+#define RGB_MATRIX_NUM_ROWS 8
+#define RGB_MATRIX_NUM_COLS 8
+#define DM163_NUM_LEDS (RGB_MATRIX_NUM_COLS * 3)
+/* The last row is filled with 0 (turned off row) */
+#define COLOR_BUFFER_SIZE (RGB_MATRIX_NUM_ROWS + 1)
+
+typedef struct DM163State {
+ DeviceState parent_obj;
+
+ /* DM163 driver */
+ uint64_t bank0_shift_register[3];
+ uint64_t bank1_shift_register[3];
+ uint16_t latched_outputs[DM163_NUM_LEDS];
+ uint16_t outputs[DM163_NUM_LEDS];
+ qemu_irq sout;
+
+ uint8_t sin;
+ uint8_t dck;
+ uint8_t rst_b;
+ uint8_t lat_b;
+ uint8_t selbk;
+ uint8_t en_b;
+
+ /* IM120417002 colors shield */
+ uint8_t activated_rows;
+
+ /* 8x8 RGB matrix */
+ QemuConsole *console;
+ uint8_t redraw;
+ /* Rows currently being displayed on the matrix. */
+ /* The last row is filled with 0 (turned off row) */
+ uint32_t buffer[COLOR_BUFFER_SIZE][RGB_MATRIX_NUM_COLS];
+ uint8_t last_buffer_idx;
+ uint8_t buffer_idx_of_row[RGB_MATRIX_NUM_ROWS];
+ /* Used to simulate retinal persistence of rows */
+ uint8_t row_persistence_delay[RGB_MATRIX_NUM_ROWS];
+} DM163State;
+
+#endif /* HW_DISPLAY_DM163_H */
