112eb90f1SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only
25320918bSDave Airlie /*
35320918bSDave Airlie * Copyright (C) 2012 Red Hat
45320918bSDave Airlie * based in parts on udlfb.c:
55320918bSDave Airlie * Copyright (C) 2009 Roberto De Ioris <roberto@unbit.it>
65320918bSDave Airlie * Copyright (C) 2009 Jaya Kumar <jayakumar.lkml@gmail.com>
75320918bSDave Airlie * Copyright (C) 2009 Bernie Thompson <bernie@plugable.com>
85320918bSDave Airlie */
95320918bSDave Airlie
100c45b36fSJonathan Neuschäfer #include <asm/unaligned.h>
115320918bSDave Airlie
125320918bSDave Airlie #include "udl_drv.h"
13*1b8db07fSThomas Zimmermann #include "udl_proto.h"
145320918bSDave Airlie
155320918bSDave Airlie #define MAX_CMD_PIXELS 255
165320918bSDave Airlie
175320918bSDave Airlie #define RLX_HEADER_BYTES 7
185320918bSDave Airlie #define MIN_RLX_PIX_BYTES 4
195320918bSDave Airlie #define MIN_RLX_CMD_BYTES (RLX_HEADER_BYTES + MIN_RLX_PIX_BYTES)
205320918bSDave Airlie
215320918bSDave Airlie #define RLE_HEADER_BYTES 6
225320918bSDave Airlie #define MIN_RLE_PIX_BYTES 3
235320918bSDave Airlie #define MIN_RLE_CMD_BYTES (RLE_HEADER_BYTES + MIN_RLE_PIX_BYTES)
245320918bSDave Airlie
255320918bSDave Airlie #define RAW_HEADER_BYTES 6
265320918bSDave Airlie #define MIN_RAW_PIX_BYTES 2
275320918bSDave Airlie #define MIN_RAW_CMD_BYTES (RAW_HEADER_BYTES + MIN_RAW_PIX_BYTES)
285320918bSDave Airlie
pixel32_to_be16(const uint32_t pixel)29e90a4ea5SChris Wilson static inline u16 pixel32_to_be16(const uint32_t pixel)
305320918bSDave Airlie {
31e90a4ea5SChris Wilson return (((pixel >> 3) & 0x001f) |
32e90a4ea5SChris Wilson ((pixel >> 5) & 0x07e0) |
33e90a4ea5SChris Wilson ((pixel >> 8) & 0xf800));
34e90a4ea5SChris Wilson }
355320918bSDave Airlie
get_pixel_val16(const uint8_t * pixel,int log_bpp)3691ba11fbSMikulas Patocka static inline u16 get_pixel_val16(const uint8_t *pixel, int log_bpp)
37e90a4ea5SChris Wilson {
3891ba11fbSMikulas Patocka u16 pixel_val16;
3991ba11fbSMikulas Patocka if (log_bpp == 1)
4086584444SHaixia Shi pixel_val16 = *(const uint16_t *)pixel;
4191ba11fbSMikulas Patocka else
4286584444SHaixia Shi pixel_val16 = pixel32_to_be16(*(const uint32_t *)pixel);
4386584444SHaixia Shi return pixel_val16;
445320918bSDave Airlie }
455320918bSDave Airlie
465320918bSDave Airlie /*
475320918bSDave Airlie * Render a command stream for an encoded horizontal line segment of pixels.
485320918bSDave Airlie *
495320918bSDave Airlie * A command buffer holds several commands.
505320918bSDave Airlie * It always begins with a fresh command header
515320918bSDave Airlie * (the protocol doesn't require this, but we enforce it to allow
525320918bSDave Airlie * multiple buffers to be potentially encoded and sent in parallel).
535320918bSDave Airlie * A single command encodes one contiguous horizontal line of pixels
545320918bSDave Airlie *
555320918bSDave Airlie * The function relies on the client to do all allocation, so that
565320918bSDave Airlie * rendering can be done directly to output buffers (e.g. USB URBs).
575320918bSDave Airlie * The function fills the supplied command buffer, providing information
585320918bSDave Airlie * on where it left off, so the client may call in again with additional
595320918bSDave Airlie * buffers if the line will take several buffers to complete.
605320918bSDave Airlie *
615320918bSDave Airlie * A single command can transmit a maximum of 256 pixels,
625320918bSDave Airlie * regardless of the compression ratio (protocol design limit).
635320918bSDave Airlie * To the hardware, 0 for a size byte means 256
645320918bSDave Airlie *
655320918bSDave Airlie * Rather than 256 pixel commands which are either rl or raw encoded,
665320918bSDave Airlie * the rlx command simply assumes alternating raw and rl spans within one cmd.
675320918bSDave Airlie * This has a slightly larger header overhead, but produces more even results.
685320918bSDave Airlie * It also processes all data (read and write) in a single pass.
695320918bSDave Airlie * Performance benchmarks of common cases show it having just slightly better
705320918bSDave Airlie * compression than 256 pixel raw or rle commands, with similar CPU consumpion.
715320918bSDave Airlie * But for very rl friendly data, will compress not quite as well.
725320918bSDave Airlie */
udl_compress_hline16(const u8 ** pixel_start_ptr,const u8 * const pixel_end,uint32_t * device_address_ptr,uint8_t ** command_buffer_ptr,const uint8_t * const cmd_buffer_end,int log_bpp)735320918bSDave Airlie static void udl_compress_hline16(
745320918bSDave Airlie const u8 **pixel_start_ptr,
755320918bSDave Airlie const u8 *const pixel_end,
765320918bSDave Airlie uint32_t *device_address_ptr,
775320918bSDave Airlie uint8_t **command_buffer_ptr,
7891ba11fbSMikulas Patocka const uint8_t *const cmd_buffer_end, int log_bpp)
795320918bSDave Airlie {
8091ba11fbSMikulas Patocka const int bpp = 1 << log_bpp;
815320918bSDave Airlie const u8 *pixel = *pixel_start_ptr;
825320918bSDave Airlie uint32_t dev_addr = *device_address_ptr;
835320918bSDave Airlie uint8_t *cmd = *command_buffer_ptr;
845320918bSDave Airlie
855320918bSDave Airlie while ((pixel_end > pixel) &&
865320918bSDave Airlie (cmd_buffer_end - MIN_RLX_CMD_BYTES > cmd)) {
8774401b1dSSachin Kamat uint8_t *raw_pixels_count_byte = NULL;
8874401b1dSSachin Kamat uint8_t *cmd_pixels_count_byte = NULL;
8974401b1dSSachin Kamat const u8 *raw_pixel_start = NULL;
9074401b1dSSachin Kamat const u8 *cmd_pixel_start, *cmd_pixel_end = NULL;
9186584444SHaixia Shi uint16_t pixel_val16;
925320918bSDave Airlie
93*1b8db07fSThomas Zimmermann *cmd++ = UDL_MSG_BULK;
94*1b8db07fSThomas Zimmermann *cmd++ = UDL_CMD_WRITERLX16;
955320918bSDave Airlie *cmd++ = (uint8_t) ((dev_addr >> 16) & 0xFF);
965320918bSDave Airlie *cmd++ = (uint8_t) ((dev_addr >> 8) & 0xFF);
975320918bSDave Airlie *cmd++ = (uint8_t) ((dev_addr) & 0xFF);
985320918bSDave Airlie
995320918bSDave Airlie cmd_pixels_count_byte = cmd++; /* we'll know this later */
1005320918bSDave Airlie cmd_pixel_start = pixel;
1015320918bSDave Airlie
1025320918bSDave Airlie raw_pixels_count_byte = cmd++; /* we'll know this later */
1035320918bSDave Airlie raw_pixel_start = pixel;
1045320918bSDave Airlie
10591ba11fbSMikulas Patocka cmd_pixel_end = pixel + (min3(MAX_CMD_PIXELS + 1UL,
10691ba11fbSMikulas Patocka (unsigned long)(pixel_end - pixel) >> log_bpp,
10791ba11fbSMikulas Patocka (unsigned long)(cmd_buffer_end - 1 - cmd) / 2) << log_bpp);
1085320918bSDave Airlie
10991ba11fbSMikulas Patocka pixel_val16 = get_pixel_val16(pixel, log_bpp);
1105320918bSDave Airlie
1115320918bSDave Airlie while (pixel < cmd_pixel_end) {
112e90a4ea5SChris Wilson const u8 *const start = pixel;
11386584444SHaixia Shi const uint16_t repeating_pixel_val16 = pixel_val16;
1145320918bSDave Airlie
1150c45b36fSJonathan Neuschäfer put_unaligned_be16(pixel_val16, cmd);
1165320918bSDave Airlie
1175320918bSDave Airlie cmd += 2;
1185320918bSDave Airlie pixel += bpp;
1195320918bSDave Airlie
12086584444SHaixia Shi while (pixel < cmd_pixel_end) {
12191ba11fbSMikulas Patocka pixel_val16 = get_pixel_val16(pixel, log_bpp);
12286584444SHaixia Shi if (pixel_val16 != repeating_pixel_val16)
12386584444SHaixia Shi break;
12486584444SHaixia Shi pixel += bpp;
12586584444SHaixia Shi }
12686584444SHaixia Shi
12786584444SHaixia Shi if (unlikely(pixel > start + bpp)) {
1285320918bSDave Airlie /* go back and fill in raw pixel count */
129e90a4ea5SChris Wilson *raw_pixels_count_byte = (((start -
13091ba11fbSMikulas Patocka raw_pixel_start) >> log_bpp) + 1) & 0xFF;
1315320918bSDave Airlie
1325320918bSDave Airlie /* immediately after raw data is repeat byte */
13391ba11fbSMikulas Patocka *cmd++ = (((pixel - start) >> log_bpp) - 1) & 0xFF;
1345320918bSDave Airlie
1355320918bSDave Airlie /* Then start another raw pixel span */
1365320918bSDave Airlie raw_pixel_start = pixel;
1375320918bSDave Airlie raw_pixels_count_byte = cmd++;
1385320918bSDave Airlie }
1395320918bSDave Airlie }
1405320918bSDave Airlie
1415320918bSDave Airlie if (pixel > raw_pixel_start) {
1425320918bSDave Airlie /* finalize last RAW span */
14391ba11fbSMikulas Patocka *raw_pixels_count_byte = ((pixel - raw_pixel_start) >> log_bpp) & 0xFF;
14499ec9e77SMikulas Patocka } else {
14599ec9e77SMikulas Patocka /* undo unused byte */
14699ec9e77SMikulas Patocka cmd--;
1475320918bSDave Airlie }
1485320918bSDave Airlie
14991ba11fbSMikulas Patocka *cmd_pixels_count_byte = ((pixel - cmd_pixel_start) >> log_bpp) & 0xFF;
15091ba11fbSMikulas Patocka dev_addr += ((pixel - cmd_pixel_start) >> log_bpp) * 2;
1515320918bSDave Airlie }
1525320918bSDave Airlie
1535320918bSDave Airlie if (cmd_buffer_end <= MIN_RLX_CMD_BYTES + cmd) {
1545320918bSDave Airlie /* Fill leftover bytes with no-ops */
1555320918bSDave Airlie if (cmd_buffer_end > cmd)
156*1b8db07fSThomas Zimmermann memset(cmd, UDL_MSG_BULK, cmd_buffer_end - cmd);
1575320918bSDave Airlie cmd = (uint8_t *) cmd_buffer_end;
1585320918bSDave Airlie }
1595320918bSDave Airlie
1605320918bSDave Airlie *command_buffer_ptr = cmd;
1615320918bSDave Airlie *pixel_start_ptr = pixel;
1625320918bSDave Airlie *device_address_ptr = dev_addr;
1635320918bSDave Airlie
1645320918bSDave Airlie return;
1655320918bSDave Airlie }
1665320918bSDave Airlie
1675320918bSDave Airlie /*
1685320918bSDave Airlie * There are 3 copies of every pixel: The front buffer that the fbdev
1695320918bSDave Airlie * client renders to, the actual framebuffer across the USB bus in hardware
1705320918bSDave Airlie * (that we can only write to, slowly, and can never read), and (optionally)
1715320918bSDave Airlie * our shadow copy that tracks what's been sent to that hardware buffer.
1725320918bSDave Airlie */
udl_render_hline(struct drm_device * dev,int log_bpp,struct urb ** urb_ptr,const char * front,char ** urb_buf_ptr,u32 byte_offset,u32 device_byte_offset,u32 byte_width)17391ba11fbSMikulas Patocka int udl_render_hline(struct drm_device *dev, int log_bpp, struct urb **urb_ptr,
1745320918bSDave Airlie const char *front, char **urb_buf_ptr,
1753916e1d7SDave Airlie u32 byte_offset, u32 device_byte_offset,
176d15e35daSThomas Zimmermann u32 byte_width)
1775320918bSDave Airlie {
1785320918bSDave Airlie const u8 *line_start, *line_end, *next_pixel;
17991ba11fbSMikulas Patocka u32 base16 = 0 + (device_byte_offset >> log_bpp) * 2;
1805320918bSDave Airlie struct urb *urb = *urb_ptr;
1815320918bSDave Airlie u8 *cmd = *urb_buf_ptr;
1825320918bSDave Airlie u8 *cmd_end = (u8 *) urb->transfer_buffer + urb->transfer_buffer_length;
1835320918bSDave Airlie
184046f4f0aSTakashi Iwai if (WARN_ON(!(log_bpp == 1 || log_bpp == 2))) {
185046f4f0aSTakashi Iwai /* need to finish URB at error from this function */
186046f4f0aSTakashi Iwai udl_urb_completion(urb);
1877350b2a3STakashi Iwai return -EINVAL;
188046f4f0aSTakashi Iwai }
189e90a4ea5SChris Wilson
1905320918bSDave Airlie line_start = (u8 *) (front + byte_offset);
1915320918bSDave Airlie next_pixel = line_start;
1925320918bSDave Airlie line_end = next_pixel + byte_width;
1935320918bSDave Airlie
1945320918bSDave Airlie while (next_pixel < line_end) {
1955320918bSDave Airlie
1965320918bSDave Airlie udl_compress_hline16(&next_pixel,
1975320918bSDave Airlie line_end, &base16,
19891ba11fbSMikulas Patocka (u8 **) &cmd, (u8 *) cmd_end, log_bpp);
1995320918bSDave Airlie
2005320918bSDave Airlie if (cmd >= cmd_end) {
2015320918bSDave Airlie int len = cmd - (u8 *) urb->transfer_buffer;
2021ca3fd96SThomas Zimmermann int ret = udl_submit_urb(dev, urb, len);
2031ca3fd96SThomas Zimmermann if (ret)
2041ca3fd96SThomas Zimmermann return ret;
2055320918bSDave Airlie urb = udl_get_urb(dev);
2065320918bSDave Airlie if (!urb)
2071ca3fd96SThomas Zimmermann return -EAGAIN;
2085320918bSDave Airlie *urb_ptr = urb;
2095320918bSDave Airlie cmd = urb->transfer_buffer;
2105320918bSDave Airlie cmd_end = &cmd[urb->transfer_buffer_length];
2115320918bSDave Airlie }
2125320918bSDave Airlie }
2135320918bSDave Airlie
2145320918bSDave Airlie *urb_buf_ptr = cmd;
2155320918bSDave Airlie
2165320918bSDave Airlie return 0;
2175320918bSDave Airlie }
218