Initial code

drivers/painter/eink_panel/qp_eink_panel.c

@@ -0,0 +1,215 @@
+// Copyright 2023 Pablo Martinez (@elpekenin)
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "qp_comms.h"
+#include "qp_draw.h"
+#include "qp_eink_panel.h"
+#include "qp_internal.h"
+#include "qp_surface.h"
+#include "qp_surface_internal.h"
+
+////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// NOTE: The way in which data is stored may break if QUANTUM_PAINTER_PIXDATA_BUFFER_SIZE is not an even number of bytes
+
+////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// Helper functions
+
+// Reset can_flush flag back to true after timeout
+uint32_t can_flush_callback(uint32_t trigger_time, void *cb_arg) {
+    eink_panel_dc_reset_painter_device_t *driver = (eink_panel_dc_reset_painter_device_t *)cb_arg;
+    driver->can_flush = true;
+    return 0;
+}
+
+// Set can_flush to false and schedule its cleanup
+void qp_eink_update_can_flush(painter_device_t device) {
+    eink_panel_dc_reset_painter_device_t *driver = (eink_panel_dc_reset_painter_device_t *)device;
+    driver->can_flush = false;
+    defer_exec(driver->timeout, can_flush_callback, (void *)device);
+}
+
+static inline void decode_masked_pixels(uint8_t *pixels, uint32_t byte, uint8_t *black, uint8_t *color) {
+    /* Convert pixel data into convenient representation, buffer holds data as:
+     * B0C0 B1C1 B2C2 B3C3 || B4C4 B5C5 B6C6 B7C7 ...
+     *
+     * This function shuffles it so we get
+     *   black_data: B7B6B5B4B3B2B1B0
+     *   color_data: C7C6C5C4C3C2C1C0
+     */
+    uint16_t raw_data = (pixels[byte] << 8) | (pixels[byte + 1]);
+
+    // clear data so we can simply |=
+    *black = 0;
+    *color = 0;
+
+    uint16_t black_mask = 1 << 15;
+    uint16_t color_mask = 1 << 14;
+
+    for (uint8_t i = 0; i < 8; ++i) {
+        bool black_bit = raw_data & black_mask;
+        bool color_bit = raw_data & color_mask;
+
+        black_mask >>= 2;
+        color_mask >>= 2;
+
+        *black |= black_bit << i;
+        *color |= color_bit << i;
+    }
+}
+
+// Interpolate any HSV888 to the nearest of the three
+static inline uint32_t hsv_distance(HSV hsv1, HSV hsv2) {
+    return (hsv1.h - hsv2.h) * (hsv1.h - hsv2.h) + (hsv1.s - hsv2.s) * (hsv1.s - hsv2.s) + (hsv1.v - hsv2.v) * (hsv1.v - hsv2.v);
+}
+
+////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// Quantum Painter API implementations
+
+// Power control
+bool qp_eink_panel_power(painter_device_t device, bool power_on) {
+    painter_driver_t *                           driver = (painter_driver_t *)device;
+    eink_panel_dc_reset_painter_driver_vtable_t *vtable = (eink_panel_dc_reset_painter_driver_vtable_t *)driver->driver_vtable;
+
+    qp_comms_command(device, power_on ? vtable->opcodes.display_on : vtable->opcodes.display_off);
+
+    return true;
+}
+
+// Screen clear
+bool qp_eink_panel_clear(painter_device_t device) {
+    painter_driver_t *driver = (painter_driver_t *)device;
+    qp_init(device, driver->rotation);
+    return true;
+}
+
+// Screen flush
+bool qp_eink_panel_flush(painter_device_t device) {
+    eink_panel_dc_reset_painter_device_t *       driver  = (eink_panel_dc_reset_painter_device_t *)device;
+    eink_panel_dc_reset_painter_driver_vtable_t *vtable  = (eink_panel_dc_reset_painter_driver_vtable_t *)driver->base.driver_vtable;
+    surface_painter_device_t *                   black   = (surface_painter_device_t *)driver->black_surface;
+    surface_painter_device_t *                   color   = (surface_painter_device_t *)driver->color_surface;
+    uint32_t                                     n_bytes = SURFACE_REQUIRED_BUFFER_BYTE_SIZE(driver->base.panel_width, driver->base.panel_height, 1);
+
+    if (!black->dirty.is_dirty && !color->dirty.is_dirty) {
+        qp_dprintf("qp_eink_panel_flush: done (no changes to be sent)\n");
+        return true;
+    }
+
+    if (!driver->can_flush) {
+        qp_dprintf("qp_eink_panel_flush: fail (can_flush == false)\n");
+        return false;
+    }
+
+    qp_comms_command(device, vtable->opcodes.send_black_data);
+    qp_comms_send(device, black->buffer, n_bytes);
+
+    qp_comms_command(device, vtable->opcodes.send_color_data);
+    qp_comms_send(device, color->buffer, n_bytes);
+
+    qp_comms_command(device, vtable->opcodes.refresh);
+
+    qp_eink_update_can_flush(device);
+
+    return true;
+}
+
+// Viewport to draw to
+bool qp_eink_panel_viewport(painter_device_t device, uint16_t left, uint16_t top, uint16_t right, uint16_t bottom) {
+    eink_panel_dc_reset_painter_device_t *driver = (eink_panel_dc_reset_painter_device_t *)device;
+
+    qp_viewport(driver->black_surface, left, top, right, bottom);
+    qp_viewport(driver->color_surface, left, top, right, bottom);
+
+    return true;
+}
+
+// Stream pixel data to the current write position
+bool qp_eink_panel_pixdata(painter_device_t device, const void *pixel_data, uint32_t native_pixel_count) {
+    eink_panel_dc_reset_painter_device_t *driver = (eink_panel_dc_reset_painter_device_t *)device;
+    uint8_t *                             pixels = (uint8_t *)pixel_data;
+
+    uint32_t i = 0;
+    uint8_t black_data, color_data;
+    while (i < native_pixel_count) {
+        // at most, 8 pixels per cycle
+        uint8_t pixels_this_loop = QP_MIN(native_pixel_count - i, 8);
+        uint32_t byte = i / 4;
+
+        // stream data to display
+        decode_masked_pixels(pixels, byte, &black_data, &color_data);
+        // this is very slow with debugging on, call the vtable's function manually instead
+        qp_pixdata(driver->black_surface, (const void *)&black_data, pixels_this_loop);
+        qp_pixdata(driver->color_surface, (const void *)&color_data, pixels_this_loop);
+
+        // update position
+        i += pixels_this_loop;
+    }
+
+    return true;
+}
+
+// Convert supplied palette entries into their native equivalents
+bool qp_eink_panel_palette_convert(painter_device_t device, int16_t palette_size, qp_pixel_t *palette) {
+    eink_panel_dc_reset_painter_device_t *driver = (eink_panel_dc_reset_painter_device_t *)device;
+
+    for (int16_t i = 0; i < palette_size; ++i) {
+        HSV      hsv            = (HSV){palette[i].hsv888.h, palette[i].hsv888.s, palette[i].hsv888.v};
+        uint32_t white_distance = hsv_distance(hsv, (HSV){ HSV_WHITE });
+        uint32_t black_distance = hsv_distance(hsv, (HSV){ HSV_BLACK });
+        uint32_t color_distance = hsv_distance(hsv, driver->color);
+
+        // Default to white
+        bool black = false;
+        bool color = false;
+
+        uint32_t min_distance = QP_MIN(white_distance, QP_MIN(black_distance, color_distance));
+        if (min_distance == black_distance)
+            black = true;
+        else if (min_distance == color_distance)
+            color = true;
+
+        uint8_t converted = (black << 1) | (color << 0);
+
+        palette[i].mono = converted ^ driver->invert_mask;
+    }
+
+    return true;
+}
+
+// Append pixels to the target location, keyed by the pixel index
+bool qp_eink_panel_append_pixels(painter_device_t device, uint8_t *target_buffer, qp_pixel_t *palette, uint32_t pixel_offset, uint32_t pixel_count, uint8_t *palette_indices) {
+    for (uint32_t i = 0; i < pixel_count; ++i) {
+        uint32_t pixel_num = pixel_offset + i;
+
+        // each pixel takes 2 bits, aka each byte holds 4 pixels, offset based on that
+        uint32_t byte_offset = pixel_num / 4;
+        uint8_t  bit_offset  = 3 - (pixel_num % 4);
+
+        // check each color bit from palette
+        bool black_bit = palette[palette_indices[i]].mono & 0b10;
+        bool color_bit = palette[palette_indices[i]].mono & 0b01;
+
+        // compute where data goes
+        // Data ends up arranged: B0R0B1R1B2R2B3R3 | ...
+        uint8_t black_mask = 1 << (2 * bit_offset + 1);
+        uint8_t color_mask = 1 << (2 * bit_offset + 0);
+
+        // add it
+        if (black_bit)
+            target_buffer[byte_offset] |= black_mask;
+        else
+            target_buffer[byte_offset] &= ~black_mask;
+
+        if (color_bit)
+            target_buffer[byte_offset] |= color_mask;
+        else
+            target_buffer[byte_offset] &= ~color_mask;
+    }
+
+    return true;
+}
+
+bool qp_eink_panel_append_pixdata(painter_device_t device, uint8_t *target_buffer, uint32_t pixdata_offset, uint8_t pixdata_byte) {
+    qp_dprintf("Shouldn't call append_pixdata on e-Ink displays\n");
+    return false;
+}

drivers/painter/eink_panel/qp_eink_panel.h

@@ -0,0 +1,86 @@
+// Copyright 2023 Pablo Martinez (@elpekenin)
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "color.h"
+#include "qp_internal.h"
+#include "qp_surface.h"
+
+#ifdef QUANTUM_PAINTER_SPI_ENABLE
+#    include "qp_comms_spi.h"
+#endif // QUANTUM_PAINTER_SPI_ENABLE
+
+////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// Helper to create buffers with the apropiate size
+#define EINK_BYTES_REQD(w, h) (SURFACE_REQUIRED_BUFFER_BYTE_SIZE(w, h, 2))
+
+////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// Common TFT panel implementation using D/C, and RST pins.
+
+// Driver vtable with extras
+typedef struct eink_panel_dc_reset_painter_driver_vtable_t {
+    painter_driver_vtable_t base; // must be first, so it can be cast to/from the painter_driver_vtable_t* type
+
+    // Whether or not the x/y coords should be swapped on 90/270 rotation
+    bool swap_window_coords;
+
+    // Opcodes for normal display operation
+    // some may not exist on some displays
+    struct {
+        uint8_t display_on;
+        uint8_t display_off;
+        uint8_t send_black_data;
+        uint8_t send_color_data;
+        uint8_t refresh;
+    } opcodes;
+} eink_panel_dc_reset_painter_driver_vtable_t;
+
+// Device definition
+typedef struct eink_panel_dc_reset_painter_device_t {
+    painter_driver_t base; // must be first, so it can be cast to/from the painter_device_t* type
+
+    // have to wait between flushes to avoid damaging the screen, time in ms
+    uint32_t timeout;
+    bool     can_flush;
+
+    /** Information about the pixel format, default values (non-inverted) are
+     *
+     * Black bit: 0 for white / 1 for black
+     * Color bit: 0 for white or black / 1 for third color
+     *
+     * Represented as a bitmask where a 1 means "needs inversion"
+     * 0000 00BC
+     */
+    HSV color;
+    uint8_t invert_mask;
+
+    // Storage for each color's data
+    painter_device_t black_surface;
+    painter_device_t color_surface;
+
+    union {
+#ifdef QUANTUM_PAINTER_SPI_ENABLE
+        // SPI-based configurables
+        qp_comms_spi_dc_reset_config_t spi_dc_reset_config;
+#endif // QUANTUM_PAINTER_SPI_ENABLE
+
+        // TODO: I2C/parallel etc.
+    };
+} eink_panel_dc_reset_painter_device_t;
+
+////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// Forward declarations for injecting into concrete driver vtables
+
+bool qp_eink_panel_power(painter_device_t device, bool power_on);
+bool qp_eink_panel_clear(painter_device_t device);
+
+void qp_eink_update_can_flush(painter_device_t device);
+bool qp_eink_panel_flush(painter_device_t device);
+
+bool qp_eink_panel_viewport(painter_device_t device, uint16_t left, uint16_t top, uint16_t right, uint16_t bottom);
+bool qp_eink_panel_pixdata(painter_device_t device, const void *pixel_data, uint32_t native_pixel_count);
+
+bool qp_eink_panel_palette_convert(painter_device_t device, int16_t palette_size, qp_pixel_t *palette);
+
+bool qp_eink_panel_append_pixels(painter_device_t device, uint8_t *target_buffer, qp_pixel_t *palette, uint32_t pixel_offset, uint32_t pixel_count, uint8_t *palette_indices);
+
+bool qp_eink_panel_append_pixdata(painter_device_t device, uint8_t *target_buffer, uint32_t pixdata_offset, uint8_t pixdata_byte);