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Atmosphere/libraries/libexosphere/source/i2c/i2c_api.cpp

205 lines
8.9 KiB
C++

/*
* Copyright (c) Atmosphère-NX
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <exosphere.hpp>
namespace ams::i2c {
namespace {
constexpr inline size_t MaxTransferSize = sizeof(u32);
constinit std::array<uintptr_t, Port_Count> g_register_addresses = [] {
std::array<uintptr_t, Port_Count> arr = {};
arr[Port_1] = secmon::MemoryRegionPhysicalDeviceI2c1.GetAddress();
arr[Port_5] = secmon::MemoryRegionPhysicalDeviceI2c5.GetAddress();
return arr;
}();
void LoadConfig(uintptr_t address) {
/* Configure for TIMEOUT and MSTR config load. */
/* NOTE: Nintendo writes value 1 to reserved bit 5 here. This bit is documented as having no meaning. */
/* We will reproduce the write just in case it is undocumented. */
reg::Write(address + I2C_CONFIG_LOAD, I2C_REG_BITS_VALUE(CONFIG_LOAD_RESERVED_BIT_5, 1),
I2C_REG_BITS_ENUM (CONFIG_LOAD_TIMEOUT_CONFIG_LOAD, ENABLE),
I2C_REG_BITS_ENUM (CONFIG_LOAD_SLV_CONFIG_LOAD, DISABLE),
I2C_REG_BITS_ENUM (CONFIG_LOAD_MSTR_CONFIG_LOAD, ENABLE));
/* Wait up to 20 microseconds for the master config to be loaded. */
for (int i = 0; i < 20; ++i) {
if (reg::HasValue(address + I2C_CONFIG_LOAD, I2C_REG_BITS_ENUM(CONFIG_LOAD_MSTR_CONFIG_LOAD, DISABLE))) {
return;
}
util::WaitMicroSeconds(1);
}
}
void ClearBus(uintptr_t address) {
/* Configure the bus clear register. */
reg::Write(address + I2C_BUS_CLEAR_CONFIG, I2C_REG_BITS_VALUE(BUS_CLEAR_CONFIG_BC_SCLK_THRESHOLD, 9),
I2C_REG_BITS_ENUM (BUS_CLEAR_CONFIG_BC_STOP_COND, NO_STOP),
I2C_REG_BITS_ENUM (BUS_CLEAR_CONFIG_BC_TERMINATE, IMMEDIATE),
I2C_REG_BITS_ENUM (BUS_CLEAR_CONFIG_BC_ENABLE, ENABLE));
/* Load the config. */
LoadConfig(address);
/* Wait up to 250us (in 25 us increments) until the bus clear is done. */
for (int i = 0; i < 10; ++i) {
if (reg::HasValue(address + I2C_INTERRUPT_STATUS_REGISTER, I2C_REG_BITS_ENUM(INTERRUPT_STATUS_REGISTER_BUS_CLEAR_DONE, SET))) {
break;
}
util::WaitMicroSeconds(25);
}
/* Read the bus clear status. */
reg::Read(address + I2C_BUS_CLEAR_STATUS);
}
void InitializePort(uintptr_t address) {
/* Calculate the divisor. */
constexpr int Divisor = util::DivideUp(19200, 8 * 400);
/* Set the divisor. */
reg::Write(address + I2C_CLK_DIVISOR_REGISTER, I2C_REG_BITS_VALUE(CLK_DIVISOR_REGISTER_STD_FAST_MODE, Divisor - 1),
I2C_REG_BITS_VALUE(CLK_DIVISOR_REGISTER_HSMODE, 1));
/* Clear the bus. */
ClearBus(address);
/* Clear the status. */
reg::Write(address + I2C_INTERRUPT_STATUS_REGISTER, reg::Read(address + I2C_INTERRUPT_STATUS_REGISTER));
}
bool Write(uintptr_t base_address, Port port, int address, const void *src, size_t src_size, bool unused) {
AMS_UNUSED(port, unused);
/* Ensure we don't write too much. */
u32 data = 0;
if (src_size > MaxTransferSize) {
return false;
}
/* Copy the data to a transfer word. */
std::memcpy(std::addressof(data), src, src_size);
/* Configure the to write the 7-bit address. */
reg::Write(base_address + I2C_I2C_CMD_ADDR0, I2C_REG_BITS_VALUE(I2C_CMD_ADDR0_7BIT_ADDR, address),
I2C_REG_BITS_ENUM (I2C_CMD_ADDR0_7BIT_RW, WRITE));
/* Configure to write the data. */
reg::Write(base_address + I2C_I2C_CMD_DATA1, data);
/* Configure to write the correct amount of data. */
reg::Write(base_address + I2C_I2C_CNFG, I2C_REG_BITS_ENUM (I2C_CNFG_DEBOUNCE_CNT, DEBOUNCE_4T),
I2C_REG_BITS_ENUM (I2C_CNFG_NEW_MASTER_FSM, ENABLE),
I2C_REG_BITS_ENUM (I2C_CNFG_CMD1, WRITE),
I2C_REG_BITS_VALUE(I2C_CNFG_LENGTH, src_size - 1));
/* Load the configuration. */
LoadConfig(base_address);
/* Start the command. */
reg::ReadWrite(base_address + I2C_I2C_CNFG, I2C_REG_BITS_ENUM(I2C_CNFG_SEND, GO));
/* Wait for the command to be done. */
while (!reg::HasValue(base_address + I2C_I2C_STATUS, I2C_REG_BITS_ENUM(I2C_STATUS_BUSY, NOT_BUSY))) { /* ... */ }
/* Check if the transfer was successful. */
return reg::HasValue(base_address + I2C_I2C_STATUS, I2C_REG_BITS_ENUM(I2C_STATUS_CMD1_STAT, SL1_XFER_SUCCESSFUL));
}
bool Read(uintptr_t base_address, Port port, void *dst, size_t dst_size, int address, bool unused) {
AMS_UNUSED(port, unused);
/* Ensure we don't read too much. */
if (dst_size > MaxTransferSize) {
return false;
}
/* Configure the to read the 7-bit address. */
reg::Write(base_address + I2C_I2C_CMD_ADDR0, I2C_REG_BITS_VALUE(I2C_CMD_ADDR0_7BIT_ADDR, address),
I2C_REG_BITS_ENUM (I2C_CMD_ADDR0_7BIT_RW, READ));
/* Configure to read the correct amount of data. */
reg::Write(base_address + I2C_I2C_CNFG, I2C_REG_BITS_ENUM (I2C_CNFG_DEBOUNCE_CNT, DEBOUNCE_4T),
I2C_REG_BITS_ENUM (I2C_CNFG_NEW_MASTER_FSM, ENABLE),
I2C_REG_BITS_ENUM (I2C_CNFG_CMD1, READ),
I2C_REG_BITS_VALUE(I2C_CNFG_LENGTH, dst_size - 1));
/* Load the configuration. */
LoadConfig(base_address);
/* Start the command. */
reg::ReadWrite(base_address + I2C_I2C_CNFG, I2C_REG_BITS_ENUM(I2C_CNFG_SEND, GO));
/* Wait for the command to be done. */
while (!reg::HasValue(base_address + I2C_I2C_STATUS, I2C_REG_BITS_ENUM(I2C_STATUS_BUSY, NOT_BUSY))) { /* ... */ }
/* Check that the transfer was successful. */
if (!reg::HasValue(base_address + I2C_I2C_STATUS, I2C_REG_BITS_ENUM(I2C_STATUS_CMD1_STAT, SL1_XFER_SUCCESSFUL))) {
return false;
}
/* Read and copy out the data. */
u32 data = reg::Read(base_address + I2C_I2C_CMD_DATA1);
std::memcpy(dst, std::addressof(data), dst_size);
return true;
}
}
void SetRegisterAddress(Port port, uintptr_t address) {
g_register_addresses[port] = address;
}
void Initialize(Port port) {
InitializePort(g_register_addresses[port]);
}
bool Query(void *dst, size_t dst_size, Port port, int address, int r) {
const uintptr_t base_address = g_register_addresses[port];
/* Select the register we want to read. */
bool success = Write(base_address, port, address, std::addressof(r), 1, false);
if (success) {
/* If we successfully selected, read data from the register. */
success = Read(base_address, port, dst, dst_size, address, true);
}
return success;
}
bool Send(Port port, int address, int r, const void *src, size_t src_size) {
const uintptr_t base_address = g_register_addresses[port];
/* Create a transfer buffer, make sure we can use it. */
u8 buffer[MaxTransferSize];
if (src_size > sizeof(buffer) - 1) {
return false;
}
/* Copy data into the buffer. */
buffer[0] = static_cast<u8>(r);
std::memcpy(buffer + 1, src, src_size);
return Write(base_address, port, address, buffer, src_size + 1, false);
}
}