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Commit dafa32c5 authored by Krzysztof Helt's avatar Krzysztof Helt Committed by Linus Torvalds
Browse files

cirrusfb: drop clock fields from cirrusfb_regs structure 



Move call to pixclock calculation into the cirrusfb_set_par_foo().  It
makes copy of clock registers redundant.

Simplify clock calculations further.

Signed-off-by: default avatarKrzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 9a85cf51

drivers/video/cirrusfb.c

+21 −29
Original line number Diff line number Diff line
@@ -327,10 +327,6 @@ static const struct { 
#endif /* CONFIG_ZORRO */



struct cirrusfb_regs {

	long freq;

	long nom;

	long den;

	long div;

	long multiplexing;

	long mclk;

	long divMCLK;
@@ -429,9 +425,7 @@ static void cirrusfb_RectFill(u8 __iomem *regbase, int bits_per_pixel, 
			      u_short width, u_short height,

			      u_char color, u_short line_length);



static void bestclock(long freq, long *best,

		      long *nom, long *den,

		      long *div, long maxfreq);

static void bestclock(long freq, int *nom, int *den, int *div);



#ifdef CIRRUSFB_DEBUG

static void cirrusfb_dump(void);
@@ -711,9 +705,6 @@ static int cirrusfb_decode_var(const struct fb_var_screeninfo *var, 
		break;

	}

#endif



	bestclock(freq, &regs->freq, &regs->nom, &regs->den, &regs->div,

		  maxclock);

	regs->mclk = cirrusfb_get_mclk(freq, var->bits_per_pixel,

					&regs->divMCLK);
@@ -756,6 +747,8 @@ static int cirrusfb_set_par_foo(struct fb_info *info) 
	const struct cirrusfb_board_info_rec *bi;

	int hdispend, hsyncstart, hsyncend, htotal;

	int yres, vdispend, vsyncstart, vsyncend, vtotal;

	long freq;

	int nom, den, div;



	DPRINTK("ENTER\n");

	DPRINTK("Requested mode: %dx%dx%d\n",
@@ -903,14 +896,17 @@ static int cirrusfb_set_par_foo(struct fb_info *info) 
	DPRINTK("CRT1a: %d\n", tmp);

	vga_wcrt(regbase, CL_CRT1A, tmp);



	freq = PICOS2KHZ(var->pixclock);

	bestclock(freq, &nom, &den, &div);



	/* set VCLK0 */

	/* hardware RefClock: 14.31818 MHz */

	/* formula: VClk = (OSC * N) / (D * (1+P)) */

	/* Example: VClk = (14.31818 * 91) / (23 * (1+1)) = 28.325 MHz */



	vga_wseq(regbase, CL_SEQRB, regs.nom);

	tmp = regs.den << 1;

	if (regs.div != 0)

	vga_wseq(regbase, CL_SEQRB, nom);

	tmp = den << 1;

	if (div != 0)

		tmp |= 1;



	/* 6 bit denom; ONLY 5434!!! (bugged me 10 days) */
@@ -2923,16 +2919,14 @@ static void cirrusfb_RectFill(u8 __iomem *regbase, int bits_per_pixel, 
 * bestclock() - determine closest possible clock lower(?) than the

 * desired pixel clock

 **************************************************************************/

static void bestclock(long freq, long *best, long *nom,

		       long *den, long *div, long maxfreq)

static void bestclock(long freq, int *nom, int *den, int *div)

{

	long n, h, d, f;

	int n, d;

	long h, diff;



	assert(best != NULL);

	assert(nom != NULL);

	assert(den != NULL);

	assert(div != NULL);

	assert(maxfreq > 0);



	*nom = 0;

	*den = 0;
@@ -2943,16 +2937,12 @@ static void bestclock(long freq, long *best, long *nom, 
	if (freq < 8000)

		freq = 8000;



	if (freq > maxfreq)

		freq = maxfreq;



	*best = 0;

	f = freq * 10;

	diff = freq;



	for (n = 32; n < 128; n++) {

		int s = 0;



		d = (143181 * n) / f;

		d = (14318 * n) / freq;

		if ((d >= 7) && (d <= 63)) {

			int temp = d;
@@ -2961,8 +2951,9 @@ static void bestclock(long freq, long *best, long *nom, 
				temp >>= 1;

			}

			h = ((14318 * n) / temp) >> s;

			if (abs(h - freq) < abs(*best - freq)) {

				*best = h;

			h = h > freq ? h - freq : freq - h;

			if (h < diff) {

				diff = h;

				*nom = n;

				*den = temp;

				*div = s;
@@ -2975,8 +2966,9 @@ static void bestclock(long freq, long *best, long *nom, 
				d >>= 1;

			}

			h = ((14318 * n) / d) >> s;

			if (abs(h - freq) < abs(*best - freq)) {

				*best = h;

			h = h > freq ? h - freq : freq - h;

			if (h < diff) {

				diff = h;

				*nom = n;

				*den = d;

				*div = s;
@@ -2985,7 +2977,7 @@ static void bestclock(long freq, long *best, long *nom, 
	}



	DPRINTK("Best possible values for given frequency:\n");

	DPRINTK("	best: %ld kHz  nom: %ld  den: %ld  div: %ld\n",

	DPRINTK("	freq: %ld kHz  nom: %d  den: %d  div: %d\n",

		freq, *nom, *den, *div);



	DPRINTK("EXIT\n");