samsung-spl2-protocol.c File Reference

Create printer's wire data for SPL2 monochrome laser printers. More...

Data Structures
struct	band_info
	Information about one band to be able to process it in parallel. More...
struct	worker_info
	Band processing is done in multiple threads. More...

Macros
#define	LINES_IN_ONE_BAND   128

Functions
static int	drv_spl2_page_header_write (struct spl2_drv *info, struct caps_drv *drvi, FILE *outstream)
static int	drv_spl2_write_band_header (unsigned band_no, unsigned dots, size_t data_size, FILE *outstream)
static int	drv_spl2_page_footer_write (unsigned copies, FILE *outstream)
static void	drv_spl2_band_exit (struct spl2_band_buffer *band)
static void	drv_spl2_line_create (size_t dcnt, uint8_t dst[dcnt], size_t scnt, const uint8_t src[scnt], size_t skip)
static void	drv_spl2_cb_fill (struct band_info *bi, struct caps_drv *drvi, unsigned band_no)
static struct worker_info *	to_worker_info (void *d)
static struct band_info *	to_band_info (struct worker_info *wi, unsigned no)
static void	drv_spl2_buffer_prepare (struct band_info *bi)
static int	spl2_drv_cb_band_process (void *anonymous_data, unsigned band_no)
static int	spl2_drv_cb_band_is_ready (void *anonymous_data, unsigned band_no)
static int	spl2_drv_cb_send (void *anonymous_data, unsigned band_no)
static struct band_info *	drv_spl2_page_bis_create (size_t cnt, unsigned hw, unsigned dots_per_line, unsigned skip)
static void	drv_spl2_page_bis_destroy (size_t cnt, struct band_info band_list[cnt])
int	ml1640_driver_page_print (struct caps_drv *drvi, void *d)

Variables
static const struct caps_worker_idx	worker

Detailed Description

This covers the following list of monochrome laser printers:

• ML1630
• ML1640
• ML2010
• ML2240
• ML2015
• ML2510

Macro Definition Documentation

LINES_IN_ONE_BAND

#define LINES_IN_ONE_BAND   128

printer accepts data in 'bands', each contains 128 lines of data

Function Documentation

drv_spl2_page_header_write()

static int drv_spl2_page_header_write ( struct spl2_drv *  info, struct caps_drv *  drvi, FILE *  outstream  )

static

Write a "page header", a data structure leading page data

Parameters

[in]	info
[in]	raster	Info about the raster for this page
[in]	outstream	Stream IO to the printer

Return values

0	On success
negative	Error codes from fwrite()

Note

Keep in mind, the used struct #page_header must be "packed", e.g. no gaps between its members

Todo:

Try to handle the copy feature of this printer. Is it relevant? Is it true, the printer's firmware supports it?

The members .pwidth and .plength carries always the real medium size in dots of the page, but always at 300 DPI (in the original Samsung driver).

drv_spl2_write_band_header()

static int drv_spl2_write_band_header ( unsigned  band_no, unsigned  dots, size_t  data_size, FILE *  outstream  )

static

Write a "band header", a data structure leading one band of data

Parameters

[in]	band_no	Number of this band
[in]	dots	Dot count in a line
[in]	data_size	Size in bytes of the following compressed band data
[in]	outstream	Where to send the data to

Returns

0 on success, negative errno else

drv_spl2_page_footer_write()

static int drv_spl2_page_footer_write ( unsigned  copies, FILE *  outstream  )

static

Write a "page footer", a data structure trailing a full page's data

Parameters

[in]	copies	Copy count of this page (max. USHRT_MAX)
[in]	outstream	Where to send the data to

Return values

0	On success
negative	Error codes from fwrite()
-EBADF	The printer device seems gone offline

Note

This will really flush the data in the stream's buffer to the printer.

The printer can make copies by its own. If the copies member of the footer is greater than 1, the printer repeats this page.

drv_spl2_band_exit()

static void drv_spl2_band_exit ( struct spl2_band_buffer *  band )

static

Free resources for band processing

Parameters

[out]

band

Structure to free

drv_spl2_line_create()

static void drv_spl2_line_create ( size_t  dcnt, uint8_t  dst[dcnt], size_t  scnt, const uint8_t  src[scnt], size_t  skip  )

static

Create a line of dots matching the printer's head requirements

Parameters

[in]	dcnt	Buffer size in bytes for the print head data in dst
[out]	dst	Buffer for the print head data
[in]	scnt	Buffer size in bytes for the source line in src
[in]	src	Buffer with the source line data
[in]	skip	Bytes to skip in src

dcnt should be the amout of bytes the driver expects for one line of dots (620 byte at 600 DPI for example)

Todo:

Printing real smaller media (A5 for example), needs a different approach, because the print head still requires 4960 dots, but the real content must be centered in the line in this case.

drv_spl2_cb_fill()

static void drv_spl2_cb_fill ( struct band_info *  bi, struct caps_drv *  drvi, unsigned  band_no  )

static

Fill the band info's band with LINES_IN_ONE_BAND from the raster image

Parameters

[out]	bi	The band info to fill (its band's input buffer)
[in]	drvi	Full job description
[in]	band_no	Number of the band to fill

This routine ensures there are always LINES_IN_ONE_BAND in the input buffer. If the raster image has less lines than required to fill a full band, the missing lines are padded with empty data (e.g. white dots, not printed).

Precondition

The band must be already prepared by a call to drv_spl2_buffer_prepare()

Todo:

Consider the non-printable offset at the left medium edge (depending on the format, line size and resolution!)

Consider the max. line length (depending on the resolution)

to_worker_info()

static struct worker_info * to_worker_info ( void *  d )

static

to_band_info()

static struct band_info * to_band_info ( struct worker_info *  wi, unsigned  no  )

static

drv_spl2_buffer_prepare()

static void drv_spl2_buffer_prepare ( struct band_info *  bi )

static

Allocate the required memory to fill and rotate one band's data

Parameters

[in,out]

bi

Band info to work on

Only the input buffer and the rotation buffer are allocated here, as they are always required. The compression buffer is optional for empty bands.

Note

Does not return in case of memory failure

Precondition

The bi must be already prepared by a call to drv_spl2_page_bis_create()

spl2_drv_cb_band_process()

static int spl2_drv_cb_band_process ( void *  anonymous_data, unsigned  band_no  )

static

Do all required steps to process one band

Parameters

[in,out]	anonymous_data	Our worker info
[in]	band_no	The band to process in this step

Return values

0	On success (here: always)

Callback from a worker thread

Memory optimized band processing. Memory is only allocated on demand and freed again as early as possible (valid only for the input and rotation buffer).

spl2_drv_cb_band_is_ready()

static int spl2_drv_cb_band_is_ready ( void *  anonymous_data, unsigned  band_no  )

static

Check if a band is processed already

Parameters

[in,out]	anonymous_data	Our worker info
[in]	band_no	The band to process in this step

Return values

0	This band isn't processed yet
1	Band is already processed

Callback from a worker thread. It is called everytime one of the worker threads signal a band as processed. If the band is already processed, this worker thread will call spl2_drv_cb_send() in the next step.

spl2_drv_cb_send()

static int spl2_drv_cb_send ( void *  anonymous_data, unsigned  band_no  )

static

Send the data of one band to the printer

Parameters

[in,out]	anonymous_data	Our worker info
[in]	band_no	The band to process in this step

Callback from a worker thread

Precondition

The bi->band.compressed data must already contain a comp_data_header

drv_spl2_page_bis_create()

static struct band_info * drv_spl2_page_bis_create ( size_t  cnt, unsigned  hw, unsigned  dots_per_line, unsigned  skip  )

static

Create the band info structures for the whole page

Parameters

[in]	cnt	Band count on this page (rounded up)
[in]	hw	Print head width in monochrome dots
[in]	dots_per_line	Monochrome raster dots in one source line (from the CAPS framework)
[in]	skip	Skip monochrome dots from the left of each source line

Creates an array of band_info structures in order to process them in parallel. A minimal set of variables are initialized, everything else happens in the threads later on (memory allocation aso.).

drv_spl2_page_bis_destroy()

static void drv_spl2_page_bis_destroy ( size_t  cnt, struct band_info  band_list[cnt]  )

static

Counterpart to drv_spl2_page_bis_create()

ml1640_driver_page_print()

int ml1640_driver_page_print	(	struct caps_drv *	drvi,
		void *	d
	)

Convert one raw page and print it.

Parameters

[in]	drvi	Full job description
[in]	d	The info structure

Return values

0	On success
negative	Errno else
-EBADF	The device seems gone offline

The image to process is expected as a monochrome bitmap, 8 pixel in one byte.

Precondition

For monochrome raster image data only (e.g. pixel size = 1)

A to be printed pixel must have its corresponding bit = 0, e,g, CAPS_RSTR_MONOCHROME0

Variable Documentation

worker

const struct caps_worker_idx worker

static

Initial value:

= {
    .idx_process = spl2_drv_cb_band_process,
    .idx_is_ready = spl2_drv_cb_band_is_ready,
    .idx_send = spl2_drv_cb_send,
}