pw_display_driver_ili9341: Simplify command writing
Created DisplayDriverILI9341::WriteCommand() to simplify display
initialization and improve performance as the data and optional
payload can be written in the same transaction.
Change-Id: I33cd9e192e4f0d6c52934e00b6ba3576bba63e91
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/experimental/+/112870
Commit-Queue: Chris Mumford <cmumford@google.com>
Reviewed-by: Anthony DiGirolamo <tonymd@google.com>
diff --git a/pw_display_driver_ili9341/display_driver.cc b/pw_display_driver_ili9341/display_driver.cc
index b17c25f..349c50e 100644
--- a/pw_display_driver_ili9341/display_driver.cc
+++ b/pw_display_driver_ili9341/display_driver.cc
@@ -58,28 +58,18 @@
}
}
-Status DisplayDriverILI9341::SendByte(Device::Transaction& transaction,
- std::byte val) {
- SetMode(Mode::kData);
- std::byte buff[1]{val};
- return transaction.Write(buff);
-}
-
-Status DisplayDriverILI9341::SendShort(Device::Transaction& transaction,
- uint16_t val) {
- SetMode(Mode::kData);
- std::byte buff[2]{
- static_cast<std::byte>(val >> 8),
- static_cast<std::byte>(val),
- };
- return transaction.Write(buff);
-}
-
-Status DisplayDriverILI9341::SendCommand(Device::Transaction& transaction,
- uint8_t cmd) {
+Status DisplayDriverILI9341::WriteCommand(Device::Transaction& transaction,
+ const Command& command) {
SetMode(Mode::kCommand);
- std::byte buff[1]{static_cast<std::byte>(cmd)};
- return transaction.Write(buff);
+ std::byte buff[1]{static_cast<std::byte>(command.command)};
+ auto s = transaction.Write(buff);
+ if (!s.ok())
+ return s;
+
+ if (command.command_data.empty())
+ return OkStatus();
+ SetMode(Mode::kData);
+ return transaction.Write(command.command_data);
}
Status DisplayDriverILI9341::Init() {
@@ -91,159 +81,199 @@
spi_device_.StartTransaction(ChipSelectBehavior::kPerWriteRead);
// ?
- SendCommand(transaction, 0xEF);
- SendByte(transaction, std::byte{0x03});
- SendByte(transaction, std::byte{0x80});
- SendByte(transaction, std::byte{0x02});
+ WriteCommand(transaction,
+ {0xEF,
+ std::array<std::byte, 3>{
+ std::byte{0x03},
+ std::byte{0x80},
+ std::byte{0x02},
+ }});
// ?
- SendCommand(transaction, 0xCF);
- SendByte(transaction, std::byte{0x00});
- SendByte(transaction, std::byte{0xC1});
- SendByte(transaction, std::byte{0x30});
+ WriteCommand(transaction,
+ {0xCF,
+ std::array<std::byte, 3>{
+ std::byte{0x00},
+ std::byte{0xC1},
+ std::byte{0x30},
+ }});
// ?
- SendCommand(transaction, 0xED);
- SendByte(transaction, std::byte{0x64});
- SendByte(transaction, std::byte{0x03});
- SendByte(transaction, std::byte{0x12});
- SendByte(transaction, std::byte{0x81});
+ WriteCommand(transaction,
+ {0xED,
+ std::array<std::byte, 4>{
+ std::byte{0x64},
+ std::byte{0x03},
+ std::byte{0x12},
+ std::byte{0x81},
+ }});
// ?
- SendCommand(transaction, 0xE8);
- SendByte(transaction, std::byte{0x85});
- SendByte(transaction, std::byte{0x00});
- SendByte(transaction, std::byte{0x78});
+ WriteCommand(transaction,
+ {0xE8,
+ std::array<std::byte, 3>{
+ std::byte{0x85},
+ std::byte{0x00},
+ std::byte{0x78},
+ }});
// ?
- SendCommand(transaction, 0xCB);
- SendByte(transaction, std::byte{0x39});
- SendByte(transaction, std::byte{0x2C});
- SendByte(transaction, std::byte{0x00});
- SendByte(transaction, std::byte{0x34});
- SendByte(transaction, std::byte{0x02});
+ WriteCommand(transaction,
+ {0xCB,
+ std::array<std::byte, 5>{
+ std::byte{0x39},
+ std::byte{0x2C},
+ std::byte{0x00},
+ std::byte{0x34},
+ std::byte{0x02},
+ }});
// ?
- SendCommand(transaction, 0xF7);
- SendByte(transaction, std::byte{0x20});
+ WriteCommand(transaction, {0xF7, std::array<std::byte, 1>{std::byte{0x20}}});
// ?
- SendCommand(transaction, 0xEA);
- SendByte(transaction, std::byte{0x00});
- SendByte(transaction, std::byte{0x00});
+ WriteCommand(transaction,
+ {0xEA,
+ std::array<std::byte, 2>{
+ std::byte{0x00},
+ std::byte{0x00},
+ }});
// Power control
- SendCommand(transaction, 0xC0);
- SendByte(transaction, std::byte{0x23});
+ WriteCommand(transaction, {0xC0, std::array<std::byte, 1>{std::byte{0x23}}});
// Power control
- SendCommand(transaction, 0xC1);
- SendByte(transaction, std::byte{0x10});
+ WriteCommand(transaction, {0xC1, std::array<std::byte, 1>{std::byte{0x10}}});
// VCM control
- SendCommand(transaction, 0xC5);
- SendByte(transaction, std::byte{0x3e});
- SendByte(transaction, std::byte{0x28});
+ WriteCommand(transaction,
+ {0xC5,
+ std::array<std::byte, 2>{
+ std::byte{0x3e},
+ std::byte{0x28},
+ }});
// VCM control
- SendCommand(transaction, 0xC7);
- SendByte(transaction, std::byte{0x86});
+ WriteCommand(transaction, {0xC7, std::array<std::byte, 1>{std::byte{0x86}}});
- SendCommand(transaction, ILI9341_MADCTL);
- // Rotation
- // SendByte(MADCTL_MX | MADCTL_BGR); // 0
- // SendByte(MADCTL_MV | MADCTL_BGR); // 1 landscape
- // SendByte(MADCTL_MY | MADCTL_BGR); // 2
- SendByte(transaction,
- MADCTL_MX | MADCTL_MY | MADCTL_MV | MADCTL_BGR); // 3 landscape
+ constexpr std::byte kMode0 = MADCTL_MX | MADCTL_BGR;
+ constexpr std::byte kMode1 = MADCTL_MV | MADCTL_BGR;
+ constexpr std::byte kMode2 = MADCTL_MY | MADCTL_BGR;
+ constexpr std::byte kMode3 = MADCTL_MX | MADCTL_MY | MADCTL_MV | MADCTL_BGR;
+ WriteCommand(transaction, {ILI9341_MADCTL, std::array<std::byte, 1>{kMode3}});
- SendCommand(transaction, ILI9341_PIXEL_FORMAT_SET);
- SendByte(transaction, std::byte{0x55}); // 16 bits / pixel
- // SendByte(0x36); // 18 bits / pixel
+ constexpr std::byte kPixelFormat16bits = std::byte(0x55);
+ constexpr std::byte kPixelFormat18bits = std::byte(0x36);
+ WriteCommand(
+ transaction,
+ {ILI9341_PIXEL_FORMAT_SET, std::array<std::byte, 1>{kPixelFormat16bits}});
// Frame Control (Normal Mode)
- SendCommand(transaction, 0xB1);
- SendByte(transaction, std::byte{0x00}); // division ratio
- SendByte(transaction, std::byte{0x1F}); // 61 Hz
- // SendByte(0x1B); // 70 Hz - default
- // SendByte(0x18); // 79 Hz
- // SendByte(0x10); // 119 Hz
+ constexpr std::byte kFrameRate61 = std::byte{0x1F};
+ constexpr std::byte kFrameRate70 = std::byte{0x1B};
+ constexpr std::byte kFrameRate79 = std::byte{0x18};
+ constexpr std::byte kFrameRate119 = std::byte{0x10};
+ WriteCommand(transaction,
+ {0xB1,
+ std::array<std::byte, 2>{
+ std::byte{0x00}, // division ratio
+ kFrameRate61,
+ }});
// Display Function Control
- SendCommand(transaction, 0xB6);
- SendByte(transaction, std::byte{0x08});
- SendByte(transaction, std::byte{0x82});
- SendByte(transaction, std::byte{0x27});
+ WriteCommand(transaction,
+ {0xB6,
+ std::array<std::byte, 3>{
+ std::byte{0x08},
+ std::byte{0x82},
+ std::byte{0x27},
+ }});
// Gamma Function Disable?
- SendCommand(transaction, 0xF2);
- SendByte(transaction, std::byte{0x00});
+ WriteCommand(transaction, {0xF2, std::array<std::byte, 1>{std::byte{0x00}}});
// Gamma Set
- SendCommand(transaction, 0x26);
- SendByte(transaction, std::byte{0x01});
+ WriteCommand(transaction, {0x26, std::array<std::byte, 1>{std::byte{0x01}}});
// Positive Gamma Correction
- SendCommand(transaction, 0xE0);
- SendByte(transaction, std::byte{0x0F});
- SendByte(transaction, std::byte{0x31});
- SendByte(transaction, std::byte{0x2B});
- SendByte(transaction, std::byte{0x0C});
- SendByte(transaction, std::byte{0x0E});
- SendByte(transaction, std::byte{0x08});
- SendByte(transaction, std::byte{0x4E});
- SendByte(transaction, std::byte{0xF1});
- SendByte(transaction, std::byte{0x37});
- SendByte(transaction, std::byte{0x07});
- SendByte(transaction, std::byte{0x10});
- SendByte(transaction, std::byte{0x03});
- SendByte(transaction, std::byte{0x0E});
- SendByte(transaction, std::byte{0x09});
- SendByte(transaction, std::byte{0x00});
+ WriteCommand(transaction,
+ {0xE0,
+ std::array<std::byte, 15>{
+ std::byte{0x0F},
+ std::byte{0x31},
+ std::byte{0x2B},
+ std::byte{0x0C},
+ std::byte{0x0E},
+ std::byte{0x08},
+ std::byte{0x4E},
+ std::byte{0xF1},
+ std::byte{0x37},
+ std::byte{0x07},
+ std::byte{0x10},
+ std::byte{0x03},
+ std::byte{0x0E},
+ std::byte{0x09},
+ std::byte{0x00},
+ }});
// Negative Gamma Correction
- SendCommand(transaction, 0xE1);
- SendByte(transaction, std::byte{0x00});
- SendByte(transaction, std::byte{0x0E});
- SendByte(transaction, std::byte{0x14});
- SendByte(transaction, std::byte{0x03});
- SendByte(transaction, std::byte{0x11});
- SendByte(transaction, std::byte{0x07});
- SendByte(transaction, std::byte{0x31});
- SendByte(transaction, std::byte{0xC1});
- SendByte(transaction, std::byte{0x48});
- SendByte(transaction, std::byte{0x08});
- SendByte(transaction, std::byte{0x0F});
- SendByte(transaction, std::byte{0x0C});
- SendByte(transaction, std::byte{0x31});
- SendByte(transaction, std::byte{0x36});
- SendByte(transaction, std::byte{0x0F});
+ WriteCommand(transaction,
+ {0xE1,
+ std::array<std::byte, 15>{
+ std::byte{0x00},
+ std::byte{0x0E},
+ std::byte{0x14},
+ std::byte{0x03},
+ std::byte{0x11},
+ std::byte{0x07},
+ std::byte{0x31},
+ std::byte{0xC1},
+ std::byte{0x48},
+ std::byte{0x08},
+ std::byte{0x0F},
+ std::byte{0x0C},
+ std::byte{0x31},
+ std::byte{0x36},
+ std::byte{0x0F},
+ }});
// Exit Sleep
- SendCommand(transaction, 0x11);
-
+ WriteCommand(transaction, {0x11, std::array<std::byte, 0>{}});
pw::spin_delay::WaitMillis(100);
// Display On
- SendCommand(transaction, 0x29);
-
+ WriteCommand(transaction, {0x29, std::array<std::byte, 0>{}});
pw::spin_delay::WaitMillis(100);
// Normal display mode on
- SendCommand(transaction, 0x13);
+ WriteCommand(transaction, {0x13, std::array<std::byte, 0>{}});
// Setup drawing full framebuffers
// Landscape drawing Column Address Set
- SendCommand(transaction, 0x2A);
- SendShort(transaction, 0);
- SendShort(transaction, kDisplayWidth - 1);
+ constexpr uint16_t kMaxColumn = kDisplayWidth - 1;
+ WriteCommand(transaction,
+ {0x2A,
+ std::array<std::byte, 4>{
+ std::byte{0x0},
+ std::byte{0x0},
+ std::byte{kMaxColumn >> 8}, // high byte of short.
+ std::byte{kMaxColumn & 0xff}, // low byte of short.
+ }});
+
// Page Address Set
- SendCommand(transaction, 0x2B);
- SendShort(transaction, 0);
- SendShort(transaction, kDisplayHeight - 1);
+ constexpr uint16_t kMaxRow = kDisplayHeight - 1;
+ WriteCommand(transaction,
+ {0x2B,
+ std::array<std::byte, 4>{
+ std::byte{0x0},
+ std::byte{0x0},
+ std::byte{kMaxRow >> 8}, // high byte of short.
+ std::byte{kMaxRow & 0xff}, // low byte of short.
+ }});
+
pw::spin_delay::WaitMillis(10);
- SendCommand(transaction, 0x2C);
+ WriteCommand(transaction, {0x2C, std::array<std::byte, 0>{}});
SetMode(Mode::kData);
pw::spin_delay::WaitMillis(100);
diff --git a/pw_display_driver_ili9341/public/pw_display_driver_ili9341/display_driver.h b/pw_display_driver_ili9341/public/pw_display_driver_ili9341/display_driver.h
index 804d085..6698524 100644
--- a/pw_display_driver_ili9341/public/pw_display_driver_ili9341/display_driver.h
+++ b/pw_display_driver_ili9341/public/pw_display_driver_ili9341/display_driver.h
@@ -75,17 +75,20 @@
kCommand,
};
+ // A command and optional data to write to the ILI9341.
+ struct Command {
+ uint8_t command;
+ ConstByteSpan command_data;
+ };
+
// Toggle the reset GPIO line to reset the display controller.
Status Reset();
// Set the command/data mode of the display controller.
void SetMode(Mode mode);
- // Send a byte to the display controller.
- Status SendByte(pw::spi::Device::Transaction& transaction, std::byte val);
- // Send a short to the display controller.
- Status SendShort(pw::spi::Device::Transaction& transaction, uint16_t val);
- // Send a command to the display controller.
- Status SendCommand(pw::spi::Device::Transaction& transaction, uint8_t cmd);
+ // Write the command to the display controller.
+ Status WriteCommand(pw::spi::Device::Transaction& transaction,
+ const Command& command);
pw::digital_io::DigitalOut& data_cmd_gpio_; // Pin to specify D/CX mode.
pw::digital_io::DigitalOut* reset_gpio_; // Optional to reset controller.
