pw_display_driver_ili9341/display_driver.cc - pigweed/experimental - Git at Google

 // Copyright 2022 The Pigweed Authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License"); you may not
 // use this file except in compliance with the License. You may obtain a copy of
 // the License at
 //
 //     https://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 // License for the specific language governing permissions and limitations under
 // the License.

 #include "pw_display_driver_ili9341/display_driver.h"

 #include "pw_digital_io/digital_io.h"
 #include "pw_framebuffer/rgb565.h"
 #include "pw_spin_delay/delay.h"

 using pw::digital_io::State;
 using pw::spi::ChipSelectBehavior;
 using pw::spi::Device;

 namespace pw::display_driver {

 namespace {

 constexpr uint16_t ILI9341_MADCTL = 0x36;
 constexpr std::byte MADCTL_MY = std::byte{0x80};
 constexpr std::byte MADCTL_MX = std::byte{0x40};
 constexpr std::byte MADCTL_MV = std::byte{0x20};
 constexpr std::byte MADCTL_ML = std::byte{0x10};
 constexpr std::byte MADCTL_RGB = std::byte{0x00};
 constexpr std::byte MADCTL_BGR = std::byte{0x08};
 constexpr std::byte MADCTL_MH = std::byte{0x04};

 constexpr uint16_t ILI9341_PIXEL_FORMAT_SET = 0x3A;

 // The ILI9341 is hard-coded at 320x240;
 constexpr int kDisplayWidth = 320;
 constexpr int kDisplayHeight = 240;
 constexpr int kDisplayNumPixels = kDisplayWidth * kDisplayHeight;

 }  // namespace

 DisplayDriverILI9341::DisplayDriverILI9341(const Config& config)
     : data_cmd_gpio_(config.data_cmd_gpio),
       reset_gpio_(config.reset_gpio),
       spi_device_(config.spi_device) {}

 void DisplayDriverILI9341::SetMode(Mode mode) {
   // Set the D/CX pin to indicate data or command values.
   if (mode == Mode::kData) {
     data_cmd_gpio_.SetState(State::kActive);
   } else {
     data_cmd_gpio_.SetState(State::kInactive);
   }
 }

 Status DisplayDriverILI9341::WriteCommand(Device::Transaction& transaction,
                                           const Command& command) {
   SetMode(Mode::kCommand);
   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() {
   Reset().IgnoreError();

   // TODO(cmumford): Figure out why kPerTransaction is flakey for this.
   // Seems to be OK on the Pico's display, but not the STM32F429I-DISC1.
   auto transaction =
       spi_device_.StartTransaction(ChipSelectBehavior::kPerWriteRead);

   // ?
   WriteCommand(transaction,
                {0xEF,
                 std::array<std::byte, 3>{
                     std::byte{0x03},
                     std::byte{0x80},
                     std::byte{0x02},
                 }});

   // ?
   WriteCommand(transaction,
                {0xCF,
                 std::array<std::byte, 3>{
                     std::byte{0x00},
                     std::byte{0xC1},
                     std::byte{0x30},
                 }});

   // ?
   WriteCommand(transaction,
                {0xED,
                 std::array<std::byte, 4>{
                     std::byte{0x64},
                     std::byte{0x03},
                     std::byte{0x12},
                     std::byte{0x81},
                 }});

   // ?
   WriteCommand(transaction,
                {0xE8,
                 std::array<std::byte, 3>{
                     std::byte{0x85},
                     std::byte{0x00},
                     std::byte{0x78},
                 }});

   // ?
   WriteCommand(transaction,
                {0xCB,
                 std::array<std::byte, 5>{
                     std::byte{0x39},
                     std::byte{0x2C},
                     std::byte{0x00},
                     std::byte{0x34},
                     std::byte{0x02},
                 }});

   // ?
   WriteCommand(transaction, {0xF7, std::array<std::byte, 1>{std::byte{0x20}}});

   // ?
   WriteCommand(transaction,
                {0xEA,
                 std::array<std::byte, 2>{
                     std::byte{0x00},
                     std::byte{0x00},
                 }});

   // Power control
   WriteCommand(transaction, {0xC0, std::array<std::byte, 1>{std::byte{0x23}}});

   // Power control
   WriteCommand(transaction, {0xC1, std::array<std::byte, 1>{std::byte{0x10}}});

   // VCM control
   WriteCommand(transaction,
                {0xC5,
                 std::array<std::byte, 2>{
                     std::byte{0x3e},
                     std::byte{0x28},
                 }});

   // VCM control
   WriteCommand(transaction, {0xC7, std::array<std::byte, 1>{std::byte{0x86}}});

   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}});

   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)
   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
   WriteCommand(transaction,
                {0xB6,
                 std::array<std::byte, 3>{
                     std::byte{0x08},
                     std::byte{0x82},
                     std::byte{0x27},
                 }});

   // Gamma Function Disable?
   WriteCommand(transaction, {0xF2, std::array<std::byte, 1>{std::byte{0x00}}});

   // Gamma Set
   WriteCommand(transaction, {0x26, std::array<std::byte, 1>{std::byte{0x01}}});

   // Positive Gamma Correction
   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
   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
   WriteCommand(transaction, {0x11, std::array<std::byte, 0>{}});
   pw::spin_delay::WaitMillis(100);

   // Display On
   WriteCommand(transaction, {0x29, std::array<std::byte, 0>{}});
   pw::spin_delay::WaitMillis(100);

   // Normal display mode on
   WriteCommand(transaction, {0x13, std::array<std::byte, 0>{}});

   // Setup drawing full framebuffers

   // Landscape drawing Column Address Set
   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
   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);
   WriteCommand(transaction, {0x2C, std::array<std::byte, 0>{}});

   SetMode(Mode::kData);
   pw::spin_delay::WaitMillis(100);

   return OkStatus();
 }

 int DisplayDriverILI9341::GetWidth() const { return kDisplayWidth; }

 int DisplayDriverILI9341::GetHeight() const { return kDisplayHeight; }

 Status DisplayDriverILI9341::Update(
     pw::framebuffer::FramebufferRgb565* frame_buffer) {
   auto transaction =
       spi_device_.StartTransaction(ChipSelectBehavior::kPerTransaction);
   const uint16_t* fb_data = frame_buffer->GetFramebufferData();
   Status s;
   // TODO(cmumford): Figure out why the STM32F429I cannot send the entire
   // framebuffer in a single write, but another display can.
 #if 1
   constexpr int kNumRowsPerSend = 10;
   static_assert(!(kDisplayHeight % kNumRowsPerSend),
                 "Cannot send fractional number of rows");
   constexpr int kNumSends = kDisplayHeight / kNumRowsPerSend;
   constexpr size_t kNumPixelsInSend = kDisplayWidth * kNumRowsPerSend;

   for (int i = 0; i < kNumSends && s.ok(); i++) {
     const uint8_t* data = reinterpret_cast<const uint8_t*>(
         &fb_data[kDisplayWidth * (kNumRowsPerSend * i)]);
     // At this point the SPI bus is in 16-bit mode, so we send the number
     // of 16-bit values (i.e. pixels).
     s = transaction.Write(ConstByteSpan(
         reinterpret_cast<const std::byte*>(data), kNumPixelsInSend));
   }
 #else
   s = transaction.Write(ConstByteSpan(
       reinterpret_cast<const std::byte*>(fb_data), kDisplayNumPixels));
 #endif
   return s;
 }

 Status DisplayDriverILI9341::UpdatePixelDouble(
     pw::framebuffer::FramebufferRgb565* frame_buffer) {
   uint16_t temp_row[kDisplayWidth];
   auto transaction =
       spi_device_.StartTransaction(ChipSelectBehavior::kPerTransaction);
   const color_rgb565_t* const fbdata = frame_buffer->GetFramebufferData();
   for (int y = 0; y < frame_buffer->GetHeight(); y++) {
     // Populate this row with each pixel repeated twice
     for (int x = 0; x < frame_buffer->GetWidth(); x++) {
       temp_row[x * 2] = fbdata[y * frame_buffer->GetWidth() + x];
       temp_row[(x * 2) + 1] = fbdata[y * frame_buffer->GetWidth() + x];
     }
     // Send this row to the display twice.
     auto s = transaction.Write(ConstByteSpan(
         reinterpret_cast<const std::byte*>(temp_row), kDisplayWidth));
     if (!s.ok())
       return s;
     s = transaction.Write(ConstByteSpan(
         reinterpret_cast<const std::byte*>(temp_row), kDisplayWidth));
     if (!s.ok())
       return s;
   }
   return OkStatus();
 }

 Status DisplayDriverILI9341::Reset() {
   if (!reset_gpio_)
     return Status::Unavailable();
   auto s = reset_gpio_->SetStateInactive();
   if (!s.ok())
     return s;
   pw::spin_delay::WaitMillis(100);
   s = reset_gpio_->SetStateActive();
   pw::spin_delay::WaitMillis(100);
   return s;
 }

 }  // namespace pw::display_driver
	// Copyright 2022 The Pigweed Authors
	//
	// Licensed under the Apache License, Version 2.0 (the "License"); you may not
	// use this file except in compliance with the License. You may obtain a copy of
	// the License at
	//
	// https://www.apache.org/licenses/LICENSE-2.0
	//
	// Unless required by applicable law or agreed to in writing, software
	// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
	// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
	// License for the specific language governing permissions and limitations under
	// the License.

	#include "pw_display_driver_ili9341/display_driver.h"

	#include "pw_digital_io/digital_io.h"
	#include "pw_framebuffer/rgb565.h"
	#include "pw_spin_delay/delay.h"

	using pw::digital_io::State;
	using pw::spi::ChipSelectBehavior;
	using pw::spi::Device;

	namespace pw::display_driver {

	namespace {

	constexpr uint16_t ILI9341_MADCTL = 0x36;
	constexpr std::byte MADCTL_MY = std::byte{0x80};
	constexpr std::byte MADCTL_MX = std::byte{0x40};
	constexpr std::byte MADCTL_MV = std::byte{0x20};
	constexpr std::byte MADCTL_ML = std::byte{0x10};
	constexpr std::byte MADCTL_RGB = std::byte{0x00};
	constexpr std::byte MADCTL_BGR = std::byte{0x08};
	constexpr std::byte MADCTL_MH = std::byte{0x04};

	constexpr uint16_t ILI9341_PIXEL_FORMAT_SET = 0x3A;

	// The ILI9341 is hard-coded at 320x240;
	constexpr int kDisplayWidth = 320;
	constexpr int kDisplayHeight = 240;
	constexpr int kDisplayNumPixels = kDisplayWidth * kDisplayHeight;

	} // namespace

	DisplayDriverILI9341::DisplayDriverILI9341(const Config& config)
	: data_cmd_gpio_(config.data_cmd_gpio),
	reset_gpio_(config.reset_gpio),
	spi_device_(config.spi_device) {}

	void DisplayDriverILI9341::SetMode(Mode mode) {
	// Set the D/CX pin to indicate data or command values.
	if (mode == Mode::kData) {
	data_cmd_gpio_.SetState(State::kActive);
	} else {
	data_cmd_gpio_.SetState(State::kInactive);
	}
	}

	Status DisplayDriverILI9341::WriteCommand(Device::Transaction& transaction,
	const Command& command) {
	SetMode(Mode::kCommand);
	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() {
	Reset().IgnoreError();

	// TODO(cmumford): Figure out why kPerTransaction is flakey for this.
	// Seems to be OK on the Pico's display, but not the STM32F429I-DISC1.
	auto transaction =
	spi_device_.StartTransaction(ChipSelectBehavior::kPerWriteRead);

	// ?
	WriteCommand(transaction,
	{0xEF,
	std::array<std::byte, 3>{
	std::byte{0x03},
	std::byte{0x80},
	std::byte{0x02},
	}});

	// ?
	WriteCommand(transaction,
	{0xCF,
	std::array<std::byte, 3>{
	std::byte{0x00},
	std::byte{0xC1},
	std::byte{0x30},
	}});

	// ?
	WriteCommand(transaction,
	{0xED,
	std::array<std::byte, 4>{
	std::byte{0x64},
	std::byte{0x03},
	std::byte{0x12},
	std::byte{0x81},
	}});

	// ?
	WriteCommand(transaction,
	{0xE8,
	std::array<std::byte, 3>{
	std::byte{0x85},
	std::byte{0x00},
	std::byte{0x78},
	}});

	// ?
	WriteCommand(transaction,
	{0xCB,
	std::array<std::byte, 5>{
	std::byte{0x39},
	std::byte{0x2C},
	std::byte{0x00},
	std::byte{0x34},
	std::byte{0x02},
	}});

	// ?
	WriteCommand(transaction, {0xF7, std::array<std::byte, 1>{std::byte{0x20}}});

	// ?
	WriteCommand(transaction,
	{0xEA,
	std::array<std::byte, 2>{
	std::byte{0x00},
	std::byte{0x00},
	}});

	// Power control
	WriteCommand(transaction, {0xC0, std::array<std::byte, 1>{std::byte{0x23}}});

	// Power control
	WriteCommand(transaction, {0xC1, std::array<std::byte, 1>{std::byte{0x10}}});

	// VCM control
	WriteCommand(transaction,
	{0xC5,
	std::array<std::byte, 2>{
	std::byte{0x3e},
	std::byte{0x28},
	}});

	// VCM control
	WriteCommand(transaction, {0xC7, std::array<std::byte, 1>{std::byte{0x86}}});

	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}});

	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)
	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
	WriteCommand(transaction,
	{0xB6,
	std::array<std::byte, 3>{
	std::byte{0x08},
	std::byte{0x82},
	std::byte{0x27},
	}});

	// Gamma Function Disable?
	WriteCommand(transaction, {0xF2, std::array<std::byte, 1>{std::byte{0x00}}});

	// Gamma Set
	WriteCommand(transaction, {0x26, std::array<std::byte, 1>{std::byte{0x01}}});

	// Positive Gamma Correction
	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
	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
	WriteCommand(transaction, {0x11, std::array<std::byte, 0>{}});
	pw::spin_delay::WaitMillis(100);

	// Display On
	WriteCommand(transaction, {0x29, std::array<std::byte, 0>{}});
	pw::spin_delay::WaitMillis(100);

	// Normal display mode on
	WriteCommand(transaction, {0x13, std::array<std::byte, 0>{}});

	// Setup drawing full framebuffers

	// Landscape drawing Column Address Set
	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
	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);
	WriteCommand(transaction, {0x2C, std::array<std::byte, 0>{}});

	SetMode(Mode::kData);
	pw::spin_delay::WaitMillis(100);

	return OkStatus();
	}

	int DisplayDriverILI9341::GetWidth() const { return kDisplayWidth; }

	int DisplayDriverILI9341::GetHeight() const { return kDisplayHeight; }

	Status DisplayDriverILI9341::Update(
	pw::framebuffer::FramebufferRgb565* frame_buffer) {
	auto transaction =
	spi_device_.StartTransaction(ChipSelectBehavior::kPerTransaction);
	const uint16_t* fb_data = frame_buffer->GetFramebufferData();
	Status s;
	// TODO(cmumford): Figure out why the STM32F429I cannot send the entire
	// framebuffer in a single write, but another display can.
	#if 1
	constexpr int kNumRowsPerSend = 10;
	static_assert(!(kDisplayHeight % kNumRowsPerSend),
	"Cannot send fractional number of rows");
	constexpr int kNumSends = kDisplayHeight / kNumRowsPerSend;
	constexpr size_t kNumPixelsInSend = kDisplayWidth * kNumRowsPerSend;

	for (int i = 0; i < kNumSends && s.ok(); i++) {
	const uint8_t* data = reinterpret_cast<const uint8_t*>(
	&fb_data[kDisplayWidth * (kNumRowsPerSend * i)]);
	// At this point the SPI bus is in 16-bit mode, so we send the number
	// of 16-bit values (i.e. pixels).
	s = transaction.Write(ConstByteSpan(
	reinterpret_cast<const std::byte*>(data), kNumPixelsInSend));
	}
	#else
	s = transaction.Write(ConstByteSpan(
	reinterpret_cast<const std::byte*>(fb_data), kDisplayNumPixels));
	#endif
	return s;
	}

	Status DisplayDriverILI9341::UpdatePixelDouble(
	pw::framebuffer::FramebufferRgb565* frame_buffer) {
	uint16_t temp_row[kDisplayWidth];
	auto transaction =
	spi_device_.StartTransaction(ChipSelectBehavior::kPerTransaction);
	const color_rgb565_t* const fbdata = frame_buffer->GetFramebufferData();
	for (int y = 0; y < frame_buffer->GetHeight(); y++) {
	// Populate this row with each pixel repeated twice
	for (int x = 0; x < frame_buffer->GetWidth(); x++) {
	temp_row[x * 2] = fbdata[y * frame_buffer->GetWidth() + x];
	temp_row[(x * 2) + 1] = fbdata[y * frame_buffer->GetWidth() + x];
	}
	// Send this row to the display twice.
	auto s = transaction.Write(ConstByteSpan(
	reinterpret_cast<const std::byte*>(temp_row), kDisplayWidth));
	if (!s.ok())
	return s;
	s = transaction.Write(ConstByteSpan(
	reinterpret_cast<const std::byte*>(temp_row), kDisplayWidth));
	if (!s.ok())
	return s;
	}
	return OkStatus();
	}

	Status DisplayDriverILI9341::Reset() {
	if (!reset_gpio_)
	return Status::Unavailable();
	auto s = reset_gpio_->SetStateInactive();
	if (!s.ok())
	return s;
	pw::spin_delay::WaitMillis(100);
	s = reset_gpio_->SetStateActive();
	pw::spin_delay::WaitMillis(100);
	return s;
	}

	} // namespace pw::display_driver