Added WFH0420CZ35 driver.

.gitignore

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+/cmake-build-*
+

CMakeLists.txt

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+cmake_minimum_required(VERSION 3.10)
+
+project(epd-spi)
+
+set(EPD_SOURCES
+    "src/epd_common.c"
+    "src/epd_wfh0420cz35.c"
+)
+
+set(EPD_INCLUDES
+    "include"
+)
+
+add_library(${PROJECT_NAME} ${EPD_SOURCES})
+target_include_directories(${PROJECT_NAME} PUBLIC ${EPD_INCLUDES})

include/epd_common.h

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+#ifndef EPD_COMMON_H
+#define EPD_COMMON_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+typedef enum { EPD_OK = 0, EPD_FAIL } epd_ret_t;
+
+typedef struct {
+    epd_ret_t (*write_command_cb)(void *handle, uint8_t *command, uint32_t len);
+    epd_ret_t (*write_data_cb)(void *handle, uint8_t *data, uint32_t len);
+    epd_ret_t (*reset_cb)(void *handle);
+    epd_ret_t (*poll_busy_cb)(void *handle);
+    epd_ret_t (*delay_cb)(void *handle, uint32_t msec);
+} epd_cb_t;
+
+typedef struct {
+    uint32_t x_start;
+    uint32_t x_end;
+    uint32_t y_start;
+    uint32_t y_end;
+} epd_coord_t;
+
+#define EPD_ASSERT(x) if(!(x)) for(;;) { /* ABORT. */}
+#define EPD_ERROR_CHECK(x) if(x != EPD_OK) return EPD_FAIL
+
+#endif

include/epd_private.h

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+#ifndef EPD_PRIVATE_H
+#define EPD_PRIVATE_H
+
+#include "epd_common.h"
+
+epd_ret_t epd_common_execute_sequence(epd_cb_t *cb, void *user_data, uint8_t *seq, uint32_t seq_len);
+
+#endif

include/epd_wfh0420cz35.h

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+#ifndef EPD_WFH0420CZ35_H
+#define EPD_WFH0420CZ35_h
+
+#include "epd_common.h"
+
+typedef struct {
+    void    *user_data;
+    epd_cb_t cb;
+} epd_wfh0420_t;
+
+epd_ret_t epd_wfh0420_upload(epd_wfh0420_t *epd, epd_coord_t *coord, uint8_t *red_data, uint8_t *bw_data);
+
+#endif

src/epd_common.c

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+#include "epd_common.h"
+
+/**
+ * @brief Execute command sequence.
+ * Sequence format: 1 byte parameter length, 1 byte command, [length] bytes params.
+ * Parameter length does not include command itself.
+ * @param cb epd_cb_t callback
+ * @param user_data user pointer
+ * @param seq sequence array
+ * @param seq_len sequence length
+ * @return epd_ret_t 
+ */
+epd_ret_t epd_common_execute_sequence(epd_cb_t *cb, void *user_data, uint8_t *seq, uint32_t seq_len) {
+    EPD_ASSERT(cb->write_command_cb != NULL);
+
+    uint32_t i = 0;
+    while(i < seq_len) {
+        EPD_ERROR_CHECK(cb->write_command_cb(user_data, &seq[i + 1], seq[i] + 1));
+        i += seq[i] + 2;
+    }
+
+    return EPD_OK;
+}

src/epd_wfh0420cz35.c

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+#include "epd_wfh0420cz35.h"
+
+#include "epd_private.h"
+
+#define DTM1 0x10
+#define DTM2 0x13
+
+static uint8_t epd_wfh0420_init_sequence[] = {
+    0x03, 0x06, 0x17, 0x17, 0x17,
+};
+
+static epd_ret_t epd_wfh0420_init(epd_wfh0420_t *epd) {
+    EPD_ASSERT(epd);
+    EPD_ASSERT(epd->cb.reset_cb);
+    EPD_ASSERT(epd->cb.write_command_cb);
+    EPD_ASSERT(epd->cb.poll_busy_cb);
+
+    EPD_ERROR_CHECK(epd->cb.reset_cb(epd->user_data));
+
+    EPD_ERROR_CHECK(epd_common_execute_sequence(&epd->cb, epd->user_data, epd_wfh0420_init_sequence,
+                                                sizeof(epd_wfh0420_init_sequence)));
+
+    // Issue power on command
+    uint8_t tx_buf[2] = {0x04, 0x00};
+    EPD_ERROR_CHECK(epd->cb.write_command_cb(epd->user_data, tx_buf, 0x01));
+
+    EPD_ERROR_CHECK(epd->cb.poll_busy_cb(epd->user_data));
+
+    // Issue panel setting command, LUT from OTP.
+    tx_buf[0] = 0x00;
+    tx_buf[1] = 0x0F;
+    EPD_ERROR_CHECK(epd->cb.write_command_cb(epd->user_data, tx_buf, 0x02));
+
+    return EPD_OK;
+}
+
+static epd_ret_t epd_wfh0420_partial(epd_wfh0420_t *epd, epd_coord_t *coord) {
+    EPD_ASSERT(epd);
+    EPD_ASSERT(epd->cb.write_command_cb);
+
+    // Partial In
+    uint8_t tx_buf[10] = {0x91, 0x00};
+    EPD_ERROR_CHECK(epd->cb.write_command_cb(epd->user_data, tx_buf, 1));
+
+    // Partial window
+    tx_buf[0] = 0x90;
+    tx_buf[1] = (coord->x_start >> 8U) & 0x01U;
+    tx_buf[2] = coord->x_start & 0xF8U;  // Bank number, last 3 LSBs must be zero.
+    tx_buf[3] = (coord->x_end >> 8U) & 0x01U;
+    tx_buf[4] = coord->x_end & 0xF8U;  // Same as above.
+    tx_buf[5] = (coord->y_start >> 8U) & 0x01U;
+    tx_buf[6] = coord->y_start & 0xFFU;
+    tx_buf[7] = (coord->y_end >> 8U) & 0x01U;
+    tx_buf[8] = coord->y_end & 0xFFU;
+    tx_buf[9] = 0x01; // Only scan partial area.
+    EPD_ERROR_CHECK(epd->cb.write_command_cb(epd->user_data, tx_buf, 10));
+
+    return EPD_OK;
+}
+
+static epd_ret_t epd_wfh0420_dtm(epd_wfh0420_t *epd, uint8_t dtm_num, uint8_t *data, uint32_t len) {
+    EPD_ASSERT(epd);
+    EPD_ASSERT(epd->cb.write_command_cb);
+
+    uint8_t tx_buf[2] = {dtm_num};
+
+    // Issue DTM1 or DTM2 command
+    EPD_ERROR_CHECK(epd->cb.write_command_cb(epd->user_data, tx_buf, 0x01));
+    // Send data
+    EPD_ERROR_CHECK(epd->cb.write_data_cb(epd->user_data, data, len));
+    // Issue DSP command.
+    tx_buf[0] = 0x11;
+    EPD_ERROR_CHECK(epd->cb.write_command_cb(epd->user_data, tx_buf, 0x01));
+
+    return EPD_OK;
+}
+
+static epd_ret_t epd_wfh0420_update_and_sleep(epd_wfh0420_t *epd) {
+    EPD_ASSERT(epd);
+    EPD_ASSERT(epd->cb.write_command_cb);
+    EPD_ASSERT(epd->cb.delay_cb);
+
+    // Issue DRF command
+    uint8_t tx_buf[2] = {0x12, 0x00};
+    EPD_ERROR_CHECK(epd->cb.write_command_cb(epd->user_data, tx_buf, 0x01));
+
+    // Delay 100ms and wait for busy
+    EPD_ERROR_CHECK(epd->cb.delay_cb(epd->user_data, 100));
+    EPD_ERROR_CHECK(epd->cb.poll_busy_cb(epd->user_data));
+
+    // Issue POF command
+    tx_buf[0] = 0x02;
+    EPD_ERROR_CHECK(epd->cb.write_command_cb(epd->user_data, tx_buf, 0x01));
+    EPD_ERROR_CHECK(epd->cb.poll_busy_cb(epd->user_data));
+
+    // Issue DSLP command
+    tx_buf[0] = 0x07;
+    tx_buf[1] = 0xA5;
+    EPD_ERROR_CHECK(epd->cb.write_command_cb(epd->user_data, tx_buf, 0x02));
+
+    return EPD_OK;
+}
+
+epd_ret_t epd_wfh0420_upload(epd_wfh0420_t *epd, epd_coord_t *coord, uint8_t *red_data, uint8_t *bw_data) {
+    EPD_ERROR_CHECK(epd_wfh0420_init(epd));
+    EPD_ERROR_CHECK(epd_wfh0420_partial(epd, coord));
+
+    uint8_t  bank_start = coord->x_start / 8;  // Wrap to bank
+    uint8_t  bank_end   = coord->x_end / 8;    // Wrap to bank
+    uint32_t tx_len     = (bank_end - bank_start + 1) * (coord->y_end - coord->y_start + 1);
+
+    EPD_ERROR_CHECK(epd_wfh0420_dtm(epd, DTM1, bw_data, tx_len));
+    EPD_ERROR_CHECK(epd_wfh0420_dtm(epd, DTM2, red_data, tx_len));
+
+    EPD_ERROR_CHECK(epd_wfh0420_update_and_sleep(epd));
+
+    return EPD_OK;
+}