mirror of
https://github.com/lupyuen/pinephone-nuttx.git
synced 2025-01-13 05:08:32 +08:00
329 lines
11 KiB
Zig
329 lines
11 KiB
Zig
//***************************************************************************
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//
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// Licensed to the Apache Software Foundation (ASF) under one or more
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// contributor license agreements. See the NOTICE file distributed with
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// this work for additional information regarding copyright ownership. The
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// ASF licenses this file to you under the Apache License, Version 2.0 (the
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// "License"); you may not use this file except in compliance with the
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// License. You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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// License for the specific language governing permissions and limitations
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// under the License.
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//
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//***************************************************************************
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//! PinePhone MIPI DSI Driver for Apache NuttX RTOS.
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//! This MIPI DSI Interface is compatible with Zephyr MIPI DSI:
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//! https://github.com/zephyrproject-rtos/zephyr/blob/main/include/zephyr/drivers/mipi_dsi.h
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/// Import the Zig Standard Library
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const std = @import("std");
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/// Import the LoRaWAN Library from C
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const c = @cImport({
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// NuttX Defines
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@cDefine("__NuttX__", "");
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@cDefine("NDEBUG", "");
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@cDefine("FAR", "");
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// NuttX Header Files
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@cInclude("arch/types.h");
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@cInclude("../../nuttx/include/limits.h");
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@cInclude("nuttx/config.h");
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@cInclude("inttypes.h");
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@cInclude("unistd.h");
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@cInclude("stdlib.h");
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@cInclude("stdio.h");
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});
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/// MIPI DSI Processor-to-Peripheral transaction types
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const MIPI_DSI_DCS_LONG_WRITE = 0x39;
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/// Write to MIPI DSI. See https://lupyuen.github.io/articles/dsi#transmit-packet-over-mipi-dsi
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pub export fn nuttx_mipi_dsi_dcs_write(
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dev: [*c]const mipi_dsi_device, // MIPI DSI Host Device
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channel: u8, // Virtual Channel ID
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cmd: u8, // DCS Command
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buf: [*c]u8, // Transmit Buffer
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len: usize // Length of Buffer
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) isize { // On Success: Return number of written bytes. On Error: Return negative error code
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_ = dev;
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debug("mipi_dsi_dcs_write: channel={}, cmd={x}, len={}", .{ channel, cmd, len });
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assert(cmd == MIPI_DSI_DCS_LONG_WRITE);
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// Compose Long Packet
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const pkt = composeLongPacket(channel, cmd, buf, len);
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// TODO: Dump the packet
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_ = pkt;
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// TODO
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// - Write the Long Packet to DSI_CMD_TX_REG
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// (DSI Low Power Transmit Package Register) at Offset 0x300 to 0x3FC.
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//
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// - Set the Packet Length (TX_Size) in Bits 0 to 7 of
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// DSI_CMD_CTL_REG (DSI Low Power Control Register) at Offset 0x200.
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//
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// - Set DSI_INST_JUMP_SEL_REG (Offset 0x48, undocumented)
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// to begin the Low Power Transmission.
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//
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// - Disable DSI Processing: Set Instru_En to 0.
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// - Then Enable DSI Processing: Set Instru_En to 1.
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//
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// - To check whether the transmission is complete, we poll on Instru_En.
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//
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// Instru_En is Bit 0 of DSI_BASIC_CTL0_REG
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// (DSI Configuration Register 0) at Offset 0x10.
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std.debug.panic("nuttx_mipi_dsi_dcs_write not implemented", .{});
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return 0;
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}
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// Compose MIPI DSI Long Packet. See https://lupyuen.github.io/articles/dsi#long-packet-for-mipi-dsi
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fn composeLongPacket(
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channel: u8, // Virtual Channel ID
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cmd: u8, // DCS Command
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buf: [*c]u8, // Transmit Buffer
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len: usize // Length of Buffer
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) []u8 {
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_ = buf;
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debug("composeLongPacket: channel={}, cmd={x}, len={}", .{ channel, cmd, len });
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// Data Identifier (DI) (1 byte):
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// - Virtual Channel Identifier (Bits 6 to 7)
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// - Data Type (Bits 0 to 5)
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// (Virtual Channel should be 0, I think)
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assert(cmd < (1 << 6));
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const vc: u8 = 0;
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const dt: u8 = cmd;
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const di: u8 = (vc << 6) | dt;
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// Word Count (WC) (2 bytes)：
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// - Number of bytes in the Packet Payload
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const wc: u16 = @intCast(u16, len);
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const wcl: u8 = @intCast(u8, wc & 0xff);
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const wch: u8 = @intCast(u8, wc >> 8);
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// Data Identifier + Word Count (3 bytes): For computing Error Correction Code (ECC)
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const di_wc = [3]u8 { di, wcl, wch };
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// Compute Error Correction Code (ECC) for Data Identifier + Word Count
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const ecc: u8 = computeEcc(di_wc);
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// TODO: Checksum (CS) (2 bytes):
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// - 16-bit Cyclic Redundancy Check (CRC)
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// See "12.3.6.13: Packet Footer", Page 210 of BL808 Reference Manual:
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// https://github.com/sipeed/sipeed2022_autumn_competition/blob/main/assets/BL808_RM_en.pdf)
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const cs: u16 = 0;
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const csl: u8 = @intCast(u8, cs & 0xff);
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const csh: u8 = @intCast(u8, cs >> 8);
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// Packet Header (4 bytes):
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// - Data Identifier + Word Count + Error Correction COde
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const header = [4]u8 { di_wc[0], di_wc[1], di_wc[2], ecc };
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// Packet Payload:
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// - Data (0 to 65,541 bytes):
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// Number of data bytes should match the Word Count (WC)
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assert(len <= 65_541);
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const payload = buf[0..len];
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// Packet Footer (2 bytes)
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// - Checksum (CS)
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const footer = [2]u8 { csl, csh };
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// Packet = Packet Header + Payload + Packet Footer
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var pkt = std.mem.zeroes([1024]u8);
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assert(pkt.len >= header.len + len + footer.len); // Increase pkt size
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std.mem.copy(u8, pkt[0..header.len], &header);
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std.mem.copy(u8, pkt[header.len..], payload);
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std.mem.copy(u8, pkt[(header.len + len)..], &footer);
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const pktlen = header.len + len + footer.len;
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// Return the packet
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return pkt[0..pktlen];
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}
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/// Compute the Error Correction Code (ECC) (1 byte):
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/// Allow single-bit errors to be corrected and 2-bit errors to be detected in the Packet Header
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/// See "12.3.6.12: Error Correction Code", Page 208 of BL808 Reference Manual:
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/// https://github.com/sipeed/sipeed2022_autumn_competition/blob/main/assets/BL808_RM_en.pdf)
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fn computeEcc(
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di_wc: [3]u8 // Data Identifier + Word Count (3 bytes)
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) u8 {
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// Combine DI and WC into a 24-bit word
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var di_wc_word: u32 =
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di_wc[0]
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| (@intCast(u32, di_wc[1]) << 8)
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| (@intCast(u32, di_wc[2]) << 16);
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// Extract the 24 bits from the word
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var d = std.mem.zeroes([24]u1);
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var i: usize = 0;
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while (i < 24) : (i += 1) {
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d[i] = @intCast(u1, di_wc_word & 1);
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di_wc_word >>= 1;
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}
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// Compute the ECC bits
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var ecc = std.mem.zeroes([8]u1);
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ecc[7] = 0;
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ecc[6] = 0;
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ecc[5] = d[10] ^ d[11] ^ d[12] ^ d[13] ^ d[14] ^ d[15] ^ d[16] ^ d[17] ^ d[18] ^ d[19] ^ d[21] ^ d[22] ^ d[23];
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ecc[4] = d[4] ^ d[5] ^ d[6] ^ d[7] ^ d[8] ^ d[9] ^ d[16] ^ d[17] ^ d[18] ^ d[19] ^ d[20] ^ d[22] ^ d[23];
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ecc[3] = d[1] ^ d[2] ^ d[3] ^ d[7] ^ d[8] ^ d[9] ^ d[13] ^ d[14] ^ d[15] ^ d[19] ^ d[20] ^ d[21] ^ d[23];
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ecc[2] = d[0] ^ d[2] ^ d[3] ^ d[5] ^ d[6] ^ d[9] ^ d[11] ^ d[12] ^ d[15] ^ d[18] ^ d[20] ^ d[21] ^ d[22];
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ecc[1] = d[0] ^ d[1] ^ d[3] ^ d[4] ^ d[6] ^ d[8] ^ d[10] ^ d[12] ^ d[14] ^ d[17] ^ d[20] ^ d[21] ^ d[22] ^ d[23];
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ecc[0] = d[0] ^ d[1] ^ d[2] ^ d[4] ^ d[5] ^ d[7] ^ d[10] ^ d[11] ^ d[13] ^ d[16] ^ d[20] ^ d[21] ^ d[22] ^ d[23];
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// Merge the ECC bits
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return @intCast(u8, ecc[0])
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| (@intCast(u8, ecc[1]) << 1)
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| (@intCast(u8, ecc[2]) << 2)
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| (@intCast(u8, ecc[3]) << 3)
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| (@intCast(u8, ecc[4]) << 4)
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| (@intCast(u8, ecc[5]) << 5)
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| (@intCast(u8, ecc[6]) << 6)
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| (@intCast(u8, ecc[7]) << 7);
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}
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/// MIPI DSI Device
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pub const mipi_dsi_device = extern struct {
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/// Number of Data Lanes
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data_lanes: u8,
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/// Display Timings
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timings: mipi_dsi_timings,
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/// Pixel Format
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pixfmt: u32,
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/// Mode Flags
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mode_flags: u32,
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};
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/// MIPI DSI Read / Write Message
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pub const mipi_dsi_msg = extern struct {
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/// Payload Data Type
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type: u8,
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/// Flags controlling message transmission
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flags: u16,
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/// Command (only for DCS)
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cmd: u8,
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/// Transmit Buffer Length
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tx_len: usize,
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/// Transmit Buffer
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tx_buf: [*c]const u8,
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/// Receive Buffer Length
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rx_len: usize,
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/// Receive Buffer
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rx_buf: [*c]u8,
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};
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/// MIPI DSI Display Timings
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pub const mipi_dsi_timings = extern struct {
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/// Horizontal active video
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hactive: u32,
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/// Horizontal front porch
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hfp: u32,
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/// Horizontal back porch
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hbp: u32,
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/// Horizontal sync length
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hsync: u32,
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/// Vertical active video
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vactive: u32,
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/// Vertical front porch
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vfp: u32,
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/// Vertical back porch
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vbp: u32,
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/// Vertical sync length
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vsync: u32,
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};
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/// Main Function for Null App
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pub export fn null_main(_argc: c_int, _argv: [*]const [*]const u8) c_int {
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_ = _argc;
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_ = _argv;
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test_zig();
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return 0;
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}
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/// Zig Test Function
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pub export fn test_zig() void {
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_ = printf("HELLO ZIG ON PINEPHONE!\n");
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_ = nuttx_mipi_dsi_dcs_write(null, 0, MIPI_DSI_DCS_LONG_WRITE, null, 0);
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}
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///////////////////////////////////////////////////////////////////////////////
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// Panic Handler
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/// Called by Zig when it hits a Panic. We print the Panic Message, Stack Trace and halt. See
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/// https://andrewkelley.me/post/zig-stack-traces-kernel-panic-bare-bones-os.html
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/// https://github.com/ziglang/zig/blob/master/lib/std/builtin.zig#L763-L847
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pub fn panic(
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message: []const u8,
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_stack_trace: ?*std.builtin.StackTrace
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) noreturn {
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// Print the Panic Message
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_ = _stack_trace;
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_ = puts("\n!ZIG PANIC!");
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_ = puts(@ptrCast([*c]const u8, message));
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// Print the Stack Trace
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_ = puts("Stack Trace:");
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var it = std.debug.StackIterator.init(@returnAddress(), null);
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while (it.next()) |return_address| {
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_ = printf("%p\n", return_address);
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}
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// Halt
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c.exit(1);
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}
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///////////////////////////////////////////////////////////////////////////////
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// Logging
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/// Called by Zig for `std.log.debug`, `std.log.info`, `std.log.err`, ...
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/// https://gist.github.com/leecannon/d6f5d7e5af5881c466161270347ce84d
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pub fn log(
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comptime _message_level: std.log.Level,
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comptime _scope: @Type(.EnumLiteral),
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comptime format: []const u8,
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args: anytype,
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) void {
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_ = _message_level;
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_ = _scope;
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// Format the message
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var buf: [100]u8 = undefined; // Limit to 100 chars
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var slice = std.fmt.bufPrint(&buf, format, args)
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catch { _ = puts("*** log error: buf too small"); return; };
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// Terminate the formatted message with a null
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var buf2: [buf.len + 1 : 0]u8 = undefined;
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std.mem.copy(
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u8,
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buf2[0..slice.len],
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slice[0..slice.len]
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);
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buf2[slice.len] = 0;
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// Print the formatted message
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_ = puts(&buf2);
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}
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///////////////////////////////////////////////////////////////////////////////
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// Imported Functions and Variables
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/// For safety, we import these functions ourselves to enforce Null-Terminated Strings.
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/// We changed `[*c]const u8` to `[*:0]const u8`
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extern fn printf(format: [*:0]const u8, ...) c_int;
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extern fn puts(str: [*:0]const u8) c_int;
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/// LoRaWAN Event Queue
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extern var event_queue: c.struct_ble_npl_eventq;
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/// Aliases for Zig Standard Library
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const assert = std.debug.assert;
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const debug = std.log.debug;
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