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[/] [test_project/] [trunk/] [linux_sd_driver/] [drivers/] [video/] [fbcvt.c] - Blame information for rev 62

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/*
 * linux/drivers/video/fbcvt.c - VESA(TM) Coordinated Video Timings
 *
 * Copyright (C) 2005 Antonino Daplas <adaplas@pol.net>
 *
 *      Based from the VESA(TM) Coordinated Video Timing Generator by
 *      Graham Loveridge April 9, 2003 available at
 *      http://www.vesa.org/public/CVT/CVTd6r1.xls
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file COPYING in the main directory of this archive
 * for more details.
 *
 */
#include <linux/fb.h>
 
#define FB_CVT_CELLSIZE               8
#define FB_CVT_GTF_C                 40
#define FB_CVT_GTF_J                 20
#define FB_CVT_GTF_K                128
#define FB_CVT_GTF_M                600
#define FB_CVT_MIN_VSYNC_BP         550
#define FB_CVT_MIN_VPORCH             3
#define FB_CVT_MIN_BPORCH             6
 
#define FB_CVT_RB_MIN_VBLANK        460
#define FB_CVT_RB_HBLANK            160
#define FB_CVT_RB_V_FPORCH            3
 
#define FB_CVT_FLAG_REDUCED_BLANK 1
#define FB_CVT_FLAG_MARGINS       2
#define FB_CVT_FLAG_INTERLACED    4
 
struct fb_cvt_data {
        u32 xres;
        u32 yres;
        u32 refresh;
        u32 f_refresh;
        u32 pixclock;
        u32 hperiod;
        u32 hblank;
        u32 hfreq;
        u32 htotal;
        u32 vtotal;
        u32 vsync;
        u32 hsync;
        u32 h_front_porch;
        u32 h_back_porch;
        u32 v_front_porch;
        u32 v_back_porch;
        u32 h_margin;
        u32 v_margin;
        u32 interlace;
        u32 aspect_ratio;
        u32 active_pixels;
        u32 flags;
        u32 status;
};
 
static const unsigned char fb_cvt_vbi_tab[] = {
        4,        /* 4:3      */
        5,        /* 16:9     */
        6,        /* 16:10    */
        7,        /* 5:4      */
        7,        /* 15:9     */
        8,        /* reserved */
        9,        /* reserved */
        10        /* custom   */
};
 
/* returns hperiod * 1000 */
static u32 fb_cvt_hperiod(struct fb_cvt_data *cvt)
{
        u32 num = 1000000000/cvt->f_refresh;
        u32 den;
 
        if (cvt->flags & FB_CVT_FLAG_REDUCED_BLANK) {
                num -= FB_CVT_RB_MIN_VBLANK * 1000;
                den = 2 * (cvt->yres/cvt->interlace + 2 * cvt->v_margin);
        } else {
                num -= FB_CVT_MIN_VSYNC_BP * 1000;
                den = 2 * (cvt->yres/cvt->interlace + cvt->v_margin * 2
                           + FB_CVT_MIN_VPORCH + cvt->interlace/2);
        }
 
        return 2 * (num/den);
}
 
/* returns ideal duty cycle * 1000 */
static u32 fb_cvt_ideal_duty_cycle(struct fb_cvt_data *cvt)
{
        u32 c_prime = (FB_CVT_GTF_C - FB_CVT_GTF_J) *
                (FB_CVT_GTF_K) + 256 * FB_CVT_GTF_J;
        u32 m_prime = (FB_CVT_GTF_K * FB_CVT_GTF_M);
        u32 h_period_est = cvt->hperiod;
 
        return (1000 * c_prime  - ((m_prime * h_period_est)/1000))/256;
}
 
static u32 fb_cvt_hblank(struct fb_cvt_data *cvt)
{
        u32 hblank = 0;
 
        if (cvt->flags & FB_CVT_FLAG_REDUCED_BLANK)
                hblank = FB_CVT_RB_HBLANK;
        else {
                u32 ideal_duty_cycle = fb_cvt_ideal_duty_cycle(cvt);
                u32 active_pixels = cvt->active_pixels;
 
                if (ideal_duty_cycle < 20000)
                        hblank = (active_pixels * 20000)/
                                (100000 - 20000);
                else {
                        hblank = (active_pixels * ideal_duty_cycle)/
                                (100000 - ideal_duty_cycle);
                }
        }
 
        hblank &= ~((2 * FB_CVT_CELLSIZE) - 1);
 
        return hblank;
}
 
static u32 fb_cvt_hsync(struct fb_cvt_data *cvt)
{
        u32 hsync;
 
        if (cvt->flags & FB_CVT_FLAG_REDUCED_BLANK)
                hsync = 32;
        else
                hsync = (FB_CVT_CELLSIZE * cvt->htotal)/100;
 
        hsync &= ~(FB_CVT_CELLSIZE - 1);
        return hsync;
}
 
static u32 fb_cvt_vbi_lines(struct fb_cvt_data *cvt)
{
        u32 vbi_lines, min_vbi_lines, act_vbi_lines;
 
        if (cvt->flags & FB_CVT_FLAG_REDUCED_BLANK) {
                vbi_lines = (1000 * FB_CVT_RB_MIN_VBLANK)/cvt->hperiod + 1;
                min_vbi_lines =  FB_CVT_RB_V_FPORCH + cvt->vsync +
                        FB_CVT_MIN_BPORCH;
 
        } else {
                vbi_lines = (FB_CVT_MIN_VSYNC_BP * 1000)/cvt->hperiod + 1 +
                         FB_CVT_MIN_VPORCH;
                min_vbi_lines = cvt->vsync + FB_CVT_MIN_BPORCH +
                        FB_CVT_MIN_VPORCH;
        }
 
        if (vbi_lines < min_vbi_lines)
                act_vbi_lines = min_vbi_lines;
        else
                act_vbi_lines = vbi_lines;
 
        return act_vbi_lines;
}
 
static u32 fb_cvt_vtotal(struct fb_cvt_data *cvt)
{
        u32 vtotal = cvt->yres/cvt->interlace;
 
        vtotal += 2 * cvt->v_margin + cvt->interlace/2 + fb_cvt_vbi_lines(cvt);
        vtotal |= cvt->interlace/2;
 
        return vtotal;
}
 
static u32 fb_cvt_pixclock(struct fb_cvt_data *cvt)
{
        u32 pixclock;
 
        if (cvt->flags & FB_CVT_FLAG_REDUCED_BLANK)
                pixclock = (cvt->f_refresh * cvt->vtotal * cvt->htotal)/1000;
        else
                pixclock = (cvt->htotal * 1000000)/cvt->hperiod;
 
        pixclock /= 250;
        pixclock *= 250;
        pixclock *= 1000;
 
        return pixclock;
}
 
static u32 fb_cvt_aspect_ratio(struct fb_cvt_data *cvt)
{
        u32 xres = cvt->xres;
        u32 yres = cvt->yres;
        u32 aspect = -1;
 
        if (xres == (yres * 4)/3 && !((yres * 4) % 3))
                aspect = 0;
        else if (xres == (yres * 16)/9 && !((yres * 16) % 9))
                aspect = 1;
        else if (xres == (yres * 16)/10 && !((yres * 16) % 10))
                aspect = 2;
        else if (xres == (yres * 5)/4 && !((yres * 5) % 4))
                aspect = 3;
        else if (xres == (yres * 15)/9 && !((yres * 15) % 9))
                aspect = 4;
        else {
                printk(KERN_INFO "fbcvt: Aspect ratio not CVT "
                       "standard\n");
                aspect = 7;
                cvt->status = 1;
        }
 
        return aspect;
}
 
static void fb_cvt_print_name(struct fb_cvt_data *cvt)
{
        u32 pixcount, pixcount_mod;
        int cnt = 255, offset = 0, read = 0;
        u8 *buf = kzalloc(256, GFP_KERNEL);
 
        if (!buf)
                return;
 
        pixcount = (cvt->xres * (cvt->yres/cvt->interlace))/1000000;
        pixcount_mod = (cvt->xres * (cvt->yres/cvt->interlace)) % 1000000;
        pixcount_mod /= 1000;
 
        read = snprintf(buf+offset, cnt, "fbcvt: %dx%d@%d: CVT Name - ",
                        cvt->xres, cvt->yres, cvt->refresh);
        offset += read;
        cnt -= read;
 
        if (cvt->status)
                snprintf(buf+offset, cnt, "Not a CVT standard - %d.%03d Mega "
                         "Pixel Image\n", pixcount, pixcount_mod);
        else {
                if (pixcount) {
                        read = snprintf(buf+offset, cnt, "%d", pixcount);
                        cnt -= read;
                        offset += read;
                }
 
                read = snprintf(buf+offset, cnt, ".%03dM", pixcount_mod);
                cnt -= read;
                offset += read;
 
                if (cvt->aspect_ratio == 0)
                        read = snprintf(buf+offset, cnt, "3");
                else if (cvt->aspect_ratio == 3)
                        read = snprintf(buf+offset, cnt, "4");
                else if (cvt->aspect_ratio == 1 || cvt->aspect_ratio == 4)
                        read = snprintf(buf+offset, cnt, "9");
                else if (cvt->aspect_ratio == 2)
                        read = snprintf(buf+offset, cnt, "A");
                else
                        read = 0;
                cnt -= read;
                offset += read;
 
                if (cvt->flags & FB_CVT_FLAG_REDUCED_BLANK) {
                        read = snprintf(buf+offset, cnt, "-R");
                        cnt -= read;
                        offset += read;
                }
        }
 
        printk(KERN_INFO "%s\n", buf);
        kfree(buf);
}
 
static void fb_cvt_convert_to_mode(struct fb_cvt_data *cvt,
                                   struct fb_videomode *mode)
{
        mode->refresh = cvt->f_refresh;
        mode->pixclock = KHZ2PICOS(cvt->pixclock/1000);
        mode->left_margin = cvt->h_back_porch;
        mode->right_margin = cvt->h_front_porch;
        mode->hsync_len = cvt->hsync;
        mode->upper_margin = cvt->v_back_porch;
        mode->lower_margin = cvt->v_front_porch;
        mode->vsync_len = cvt->vsync;
 
        mode->sync &= ~(FB_SYNC_HOR_HIGH_ACT | FB_SYNC_VERT_HIGH_ACT);
 
        if (cvt->flags & FB_CVT_FLAG_REDUCED_BLANK)
                mode->sync |= FB_SYNC_HOR_HIGH_ACT;
        else
                mode->sync |= FB_SYNC_VERT_HIGH_ACT;
}
 
/*
 * fb_find_mode_cvt - calculate mode using VESA(TM) CVT
 * @mode: pointer to fb_videomode; xres, yres, refresh and vmode must be
 *        pre-filled with the desired values
 * @margins: add margin to calculation (1.8% of xres and yres)
 * @rb: compute with reduced blanking (for flatpanels)
 *
 * RETURNS:
 * 0 for success
 * @mode is filled with computed values.  If interlaced, the refresh field
 * will be filled with the field rate (2x the frame rate)
 *
 * DESCRIPTION:
 * Computes video timings using VESA(TM) Coordinated Video Timings
 */
int fb_find_mode_cvt(struct fb_videomode *mode, int margins, int rb)
{
        struct fb_cvt_data cvt;
 
        memset(&cvt, 0, sizeof(cvt));
 
        if (margins)
            cvt.flags |= FB_CVT_FLAG_MARGINS;
 
        if (rb)
            cvt.flags |= FB_CVT_FLAG_REDUCED_BLANK;
 
        if (mode->vmode & FB_VMODE_INTERLACED)
            cvt.flags |= FB_CVT_FLAG_INTERLACED;
 
        cvt.xres = mode->xres;
        cvt.yres = mode->yres;
        cvt.refresh = mode->refresh;
        cvt.f_refresh = cvt.refresh;
        cvt.interlace = 1;
 
        if (!cvt.xres || !cvt.yres || !cvt.refresh) {
                printk(KERN_INFO "fbcvt: Invalid input parameters\n");
                return 1;
        }
 
        if (!(cvt.refresh == 50 || cvt.refresh == 60 || cvt.refresh == 70 ||
              cvt.refresh == 85)) {
                printk(KERN_INFO "fbcvt: Refresh rate not CVT "
                       "standard\n");
                cvt.status = 1;
        }
 
        cvt.xres &= ~(FB_CVT_CELLSIZE - 1);
 
        if (cvt.flags & FB_CVT_FLAG_INTERLACED) {
                cvt.interlace = 2;
                cvt.f_refresh *= 2;
        }
 
        if (cvt.flags & FB_CVT_FLAG_REDUCED_BLANK) {
                if (cvt.refresh != 60) {
                        printk(KERN_INFO "fbcvt: 60Hz refresh rate "
                               "advised for reduced blanking\n");
                        cvt.status = 1;
                }
        }
 
        if (cvt.flags & FB_CVT_FLAG_MARGINS) {
                cvt.h_margin = (cvt.xres * 18)/1000;
                cvt.h_margin &= ~(FB_CVT_CELLSIZE - 1);
                cvt.v_margin = ((cvt.yres/cvt.interlace)* 18)/1000;
        }
 
        cvt.aspect_ratio = fb_cvt_aspect_ratio(&cvt);
        cvt.active_pixels = cvt.xres + 2 * cvt.h_margin;
        cvt.hperiod = fb_cvt_hperiod(&cvt);
        cvt.vsync = fb_cvt_vbi_tab[cvt.aspect_ratio];
        cvt.vtotal = fb_cvt_vtotal(&cvt);
        cvt.hblank = fb_cvt_hblank(&cvt);
        cvt.htotal = cvt.active_pixels + cvt.hblank;
        cvt.hsync = fb_cvt_hsync(&cvt);
        cvt.pixclock = fb_cvt_pixclock(&cvt);
        cvt.hfreq = cvt.pixclock/cvt.htotal;
        cvt.h_back_porch = cvt.hblank/2 + cvt.h_margin;
        cvt.h_front_porch = cvt.hblank - cvt.hsync - cvt.h_back_porch +
                2 * cvt.h_margin;
        cvt.v_back_porch = 3 + cvt.v_margin;
        cvt.v_front_porch = cvt.vtotal - cvt.yres/cvt.interlace -
            cvt.v_back_porch - cvt.vsync;
        fb_cvt_print_name(&cvt);
        fb_cvt_convert_to_mode(&cvt, mode);
 
        return 0;
}

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[/] [test_project/] [trunk/] [linux_sd_driver/] [drivers/] [video/] [fbcvt.c] - Blame information for rev 62

Line No.	Rev	Author	Line
1	62	marcus.erl	`/*`
2			`* linux/drivers/video/fbcvt.c - VESA(TM) Coordinated Video Timings`
3			`*`
4			`* Copyright (C) 2005 Antonino Daplas <adaplas@pol.net>`
5			`*`
6			`* Based from the VESA(TM) Coordinated Video Timing Generator by`
7			`* Graham Loveridge April 9, 2003 available at`
8			`* http://www.vesa.org/public/CVT/CVTd6r1.xls`
9			`*`
10			`* This file is subject to the terms and conditions of the GNU General Public`
11			`* License. See the file COPYING in the main directory of this archive`
12			`* for more details.`
13			`*`
14			`*/`
15			`#include <linux/fb.h>`
16
17			`#define FB_CVT_CELLSIZE 8`
18			`#define FB_CVT_GTF_C 40`
19			`#define FB_CVT_GTF_J 20`
20			`#define FB_CVT_GTF_K 128`
21			`#define FB_CVT_GTF_M 600`
22			`#define FB_CVT_MIN_VSYNC_BP 550`
23			`#define FB_CVT_MIN_VPORCH 3`
24			`#define FB_CVT_MIN_BPORCH 6`
25
26			`#define FB_CVT_RB_MIN_VBLANK 460`
27			`#define FB_CVT_RB_HBLANK 160`
28			`#define FB_CVT_RB_V_FPORCH 3`
29
30			`#define FB_CVT_FLAG_REDUCED_BLANK 1`
31			`#define FB_CVT_FLAG_MARGINS 2`
32			`#define FB_CVT_FLAG_INTERLACED 4`
33
34			`struct fb_cvt_data {`
35			`u32 xres;`
36			`u32 yres;`
37			`u32 refresh;`
38			`u32 f_refresh;`
39			`u32 pixclock;`
40			`u32 hperiod;`
41			`u32 hblank;`
42			`u32 hfreq;`
43			`u32 htotal;`
44			`u32 vtotal;`
45			`u32 vsync;`
46			`u32 hsync;`
47			`u32 h_front_porch;`
48			`u32 h_back_porch;`
49			`u32 v_front_porch;`
50			`u32 v_back_porch;`
51			`u32 h_margin;`
52			`u32 v_margin;`
53			`u32 interlace;`
54			`u32 aspect_ratio;`
55			`u32 active_pixels;`
56			`u32 flags;`
57			`u32 status;`
58			`};`
59
60			`static const unsigned char fb_cvt_vbi_tab[] = {`
61			`4, /* 4:3 */`
62			`5, /* 16:9 */`
63			`6, /* 16:10 */`
64			`7, /* 5:4 */`
65			`7, /* 15:9 */`
66			`8, /* reserved */`
67			`9, /* reserved */`
68			`10 /* custom */`
69			`};`
70
71			`/* returns hperiod * 1000 */`
72			`static u32 fb_cvt_hperiod(struct fb_cvt_data *cvt)`
73			`{`
74			`u32 num = 1000000000/cvt->f_refresh;`
75			`u32 den;`
76
77			`if (cvt->flags & FB_CVT_FLAG_REDUCED_BLANK) {`
78			`num -= FB_CVT_RB_MIN_VBLANK * 1000;`
79			`den = 2 * (cvt->yres/cvt->interlace + 2 * cvt->v_margin);`
80			`} else {`
81			`num -= FB_CVT_MIN_VSYNC_BP * 1000;`
82			`den = 2 * (cvt->yres/cvt->interlace + cvt->v_margin * 2`
83			`+ FB_CVT_MIN_VPORCH + cvt->interlace/2);`
84			`}`
85
86			`return 2 * (num/den);`
87			`}`
88
89			`/* returns ideal duty cycle * 1000 */`
90			`static u32 fb_cvt_ideal_duty_cycle(struct fb_cvt_data *cvt)`
91			`{`
92			`u32 c_prime = (FB_CVT_GTF_C - FB_CVT_GTF_J) *`
93			`(FB_CVT_GTF_K) + 256 * FB_CVT_GTF_J;`
94			`u32 m_prime = (FB_CVT_GTF_K * FB_CVT_GTF_M);`
95			`u32 h_period_est = cvt->hperiod;`
96
97			`return (1000 * c_prime - ((m_prime * h_period_est)/1000))/256;`
98			`}`
99
100			`static u32 fb_cvt_hblank(struct fb_cvt_data *cvt)`
101			`{`
102			`u32 hblank = 0;`
103
104			`if (cvt->flags & FB_CVT_FLAG_REDUCED_BLANK)`
105			`hblank = FB_CVT_RB_HBLANK;`
106			`else {`
107			`u32 ideal_duty_cycle = fb_cvt_ideal_duty_cycle(cvt);`
108			`u32 active_pixels = cvt->active_pixels;`
109
110			`if (ideal_duty_cycle < 20000)`
111			`hblank = (active_pixels * 20000)/`
112			`(100000 - 20000);`
113			`else {`
114			`hblank = (active_pixels * ideal_duty_cycle)/`
115			`(100000 - ideal_duty_cycle);`
116			`}`
117			`}`
118
119			`hblank &= ~((2 * FB_CVT_CELLSIZE) - 1);`
120
121			`return hblank;`
122			`}`
123
124			`static u32 fb_cvt_hsync(struct fb_cvt_data *cvt)`
125			`{`
126			`u32 hsync;`
127
128			`if (cvt->flags & FB_CVT_FLAG_REDUCED_BLANK)`
129			`hsync = 32;`
130			`else`
131			`hsync = (FB_CVT_CELLSIZE * cvt->htotal)/100;`
132
133			`hsync &= ~(FB_CVT_CELLSIZE - 1);`
134			`return hsync;`
135			`}`
136
137			`static u32 fb_cvt_vbi_lines(struct fb_cvt_data *cvt)`
138			`{`
139			`u32 vbi_lines, min_vbi_lines, act_vbi_lines;`
140
141			`if (cvt->flags & FB_CVT_FLAG_REDUCED_BLANK) {`
142			`vbi_lines = (1000 * FB_CVT_RB_MIN_VBLANK)/cvt->hperiod + 1;`
143			`min_vbi_lines = FB_CVT_RB_V_FPORCH + cvt->vsync +`
144			`FB_CVT_MIN_BPORCH;`
145
146			`} else {`
147			`vbi_lines = (FB_CVT_MIN_VSYNC_BP * 1000)/cvt->hperiod + 1 +`
148			`FB_CVT_MIN_VPORCH;`
149			`min_vbi_lines = cvt->vsync + FB_CVT_MIN_BPORCH +`
150			`FB_CVT_MIN_VPORCH;`
151			`}`
152
153			`if (vbi_lines < min_vbi_lines)`
154			`act_vbi_lines = min_vbi_lines;`
155			`else`
156			`act_vbi_lines = vbi_lines;`
157
158			`return act_vbi_lines;`
159			`}`
160
161			`static u32 fb_cvt_vtotal(struct fb_cvt_data *cvt)`
162			`{`
163			`u32 vtotal = cvt->yres/cvt->interlace;`
164
165			`vtotal += 2 * cvt->v_margin + cvt->interlace/2 + fb_cvt_vbi_lines(cvt);`
166			`vtotal \|= cvt->interlace/2;`
167
168			`return vtotal;`
169			`}`
170
171			`static u32 fb_cvt_pixclock(struct fb_cvt_data *cvt)`
172			`{`
173			`u32 pixclock;`
174
175			`if (cvt->flags & FB_CVT_FLAG_REDUCED_BLANK)`
176			`pixclock = (cvt->f_refresh * cvt->vtotal * cvt->htotal)/1000;`
177			`else`
178			`pixclock = (cvt->htotal * 1000000)/cvt->hperiod;`
179
180			`pixclock /= 250;`
181			`pixclock *= 250;`
182			`pixclock *= 1000;`
183
184			`return pixclock;`
185			`}`
186
187			`static u32 fb_cvt_aspect_ratio(struct fb_cvt_data *cvt)`
188			`{`
189			`u32 xres = cvt->xres;`
190			`u32 yres = cvt->yres;`
191			`u32 aspect = -1;`
192
193			`if (xres == (yres * 4)/3 && !((yres * 4) % 3))`
194			`aspect = 0;`
195			`else if (xres == (yres * 16)/9 && !((yres * 16) % 9))`
196			`aspect = 1;`
197			`else if (xres == (yres * 16)/10 && !((yres * 16) % 10))`
198			`aspect = 2;`
199			`else if (xres == (yres * 5)/4 && !((yres * 5) % 4))`
200			`aspect = 3;`
201			`else if (xres == (yres * 15)/9 && !((yres * 15) % 9))`
202			`aspect = 4;`
203			`else {`
204			`printk(KERN_INFO "fbcvt: Aspect ratio not CVT "`
205			`"standard\n");`
206			`aspect = 7;`
207			`cvt->status = 1;`
208			`}`
209
210			`return aspect;`
211			`}`
212
213			`static void fb_cvt_print_name(struct fb_cvt_data *cvt)`
214			`{`
215			`u32 pixcount, pixcount_mod;`
216			`int cnt = 255, offset = 0, read = 0;`
217			`u8 *buf = kzalloc(256, GFP_KERNEL);`
218
219			`if (!buf)`
220			`return;`
221
222			`pixcount = (cvt->xres * (cvt->yres/cvt->interlace))/1000000;`
223			`pixcount_mod = (cvt->xres * (cvt->yres/cvt->interlace)) % 1000000;`
224			`pixcount_mod /= 1000;`
225
226			`read = snprintf(buf+offset, cnt, "fbcvt: %dx%d@%d: CVT Name - ",`
227			`cvt->xres, cvt->yres, cvt->refresh);`
228			`offset += read;`
229			`cnt -= read;`
230
231			`if (cvt->status)`
232			`snprintf(buf+offset, cnt, "Not a CVT standard - %d.%03d Mega "`
233			`"Pixel Image\n", pixcount, pixcount_mod);`
234			`else {`
235			`if (pixcount) {`
236			`read = snprintf(buf+offset, cnt, "%d", pixcount);`
237			`cnt -= read;`
238			`offset += read;`
239			`}`
240
241			`read = snprintf(buf+offset, cnt, ".%03dM", pixcount_mod);`
242			`cnt -= read;`
243			`offset += read;`
244
245			`if (cvt->aspect_ratio == 0)`
246			`read = snprintf(buf+offset, cnt, "3");`
247			`else if (cvt->aspect_ratio == 3)`
248			`read = snprintf(buf+offset, cnt, "4");`
249			`else if (cvt->aspect_ratio == 1 \|\| cvt->aspect_ratio == 4)`
250			`read = snprintf(buf+offset, cnt, "9");`
251			`else if (cvt->aspect_ratio == 2)`
252			`read = snprintf(buf+offset, cnt, "A");`
253			`else`
254			`read = 0;`
255			`cnt -= read;`
256			`offset += read;`
257
258			`if (cvt->flags & FB_CVT_FLAG_REDUCED_BLANK) {`
259			`read = snprintf(buf+offset, cnt, "-R");`
260			`cnt -= read;`
261			`offset += read;`
262			`}`
263			`}`
264
265			`printk(KERN_INFO "%s\n", buf);`
266			`kfree(buf);`
267			`}`
268
269			`static void fb_cvt_convert_to_mode(struct fb_cvt_data *cvt,`
270			`struct fb_videomode *mode)`
271			`{`
272			`mode->refresh = cvt->f_refresh;`
273			`mode->pixclock = KHZ2PICOS(cvt->pixclock/1000);`
274			`mode->left_margin = cvt->h_back_porch;`
275			`mode->right_margin = cvt->h_front_porch;`
276			`mode->hsync_len = cvt->hsync;`
277			`mode->upper_margin = cvt->v_back_porch;`
278			`mode->lower_margin = cvt->v_front_porch;`
279			`mode->vsync_len = cvt->vsync;`
280
281			`mode->sync &= ~(FB_SYNC_HOR_HIGH_ACT \| FB_SYNC_VERT_HIGH_ACT);`
282
283			`if (cvt->flags & FB_CVT_FLAG_REDUCED_BLANK)`
284			`mode->sync \|= FB_SYNC_HOR_HIGH_ACT;`
285			`else`
286			`mode->sync \|= FB_SYNC_VERT_HIGH_ACT;`
287			`}`
288
289			`/*`
290			`* fb_find_mode_cvt - calculate mode using VESA(TM) CVT`
291			`* @mode: pointer to fb_videomode; xres, yres, refresh and vmode must be`
292			`* pre-filled with the desired values`
293			`* @margins: add margin to calculation (1.8% of xres and yres)`
294			`* @rb: compute with reduced blanking (for flatpanels)`
295			`*`
296			`* RETURNS:`
297			`* 0 for success`
298			`* @mode is filled with computed values. If interlaced, the refresh field`
299			`* will be filled with the field rate (2x the frame rate)`
300			`*`
301			`* DESCRIPTION:`
302			`* Computes video timings using VESA(TM) Coordinated Video Timings`
303			`*/`
304			`int fb_find_mode_cvt(struct fb_videomode *mode, int margins, int rb)`
305			`{`
306			`struct fb_cvt_data cvt;`
307
308			`memset(&cvt, 0, sizeof(cvt));`
309
310			`if (margins)`
311			`cvt.flags \|= FB_CVT_FLAG_MARGINS;`
312
313			`if (rb)`
314			`cvt.flags \|= FB_CVT_FLAG_REDUCED_BLANK;`
315
316			`if (mode->vmode & FB_VMODE_INTERLACED)`
317			`cvt.flags \|= FB_CVT_FLAG_INTERLACED;`
318
319			`cvt.xres = mode->xres;`
320			`cvt.yres = mode->yres;`
321			`cvt.refresh = mode->refresh;`
322			`cvt.f_refresh = cvt.refresh;`
323			`cvt.interlace = 1;`
324
325			`if (!cvt.xres \|\| !cvt.yres \|\| !cvt.refresh) {`
326			`printk(KERN_INFO "fbcvt: Invalid input parameters\n");`
327			`return 1;`
328			`}`
329
330			`if (!(cvt.refresh == 50 \|\| cvt.refresh == 60 \|\| cvt.refresh == 70 \|\|`
331			`cvt.refresh == 85)) {`
332			`printk(KERN_INFO "fbcvt: Refresh rate not CVT "`
333			`"standard\n");`
334			`cvt.status = 1;`
335			`}`
336
337			`cvt.xres &= ~(FB_CVT_CELLSIZE - 1);`
338
339			`if (cvt.flags & FB_CVT_FLAG_INTERLACED) {`
340			`cvt.interlace = 2;`
341			`cvt.f_refresh *= 2;`
342			`}`
343
344			`if (cvt.flags & FB_CVT_FLAG_REDUCED_BLANK) {`
345			`if (cvt.refresh != 60) {`
346			`printk(KERN_INFO "fbcvt: 60Hz refresh rate "`
347			`"advised for reduced blanking\n");`
348			`cvt.status = 1;`
349			`}`
350			`}`
351
352			`if (cvt.flags & FB_CVT_FLAG_MARGINS) {`
353			`cvt.h_margin = (cvt.xres * 18)/1000;`
354			`cvt.h_margin &= ~(FB_CVT_CELLSIZE - 1);`
355			`cvt.v_margin = ((cvt.yres/cvt.interlace)* 18)/1000;`
356			`}`
357
358			`cvt.aspect_ratio = fb_cvt_aspect_ratio(&cvt);`
359			`cvt.active_pixels = cvt.xres + 2 * cvt.h_margin;`
360			`cvt.hperiod = fb_cvt_hperiod(&cvt);`
361			`cvt.vsync = fb_cvt_vbi_tab[cvt.aspect_ratio];`
362			`cvt.vtotal = fb_cvt_vtotal(&cvt);`
363			`cvt.hblank = fb_cvt_hblank(&cvt);`
364			`cvt.htotal = cvt.active_pixels + cvt.hblank;`
365			`cvt.hsync = fb_cvt_hsync(&cvt);`
366			`cvt.pixclock = fb_cvt_pixclock(&cvt);`
367			`cvt.hfreq = cvt.pixclock/cvt.htotal;`
368			`cvt.h_back_porch = cvt.hblank/2 + cvt.h_margin;`
369			`cvt.h_front_porch = cvt.hblank - cvt.hsync - cvt.h_back_porch +`
370			`2 * cvt.h_margin;`
371			`cvt.v_back_porch = 3 + cvt.v_margin;`
372			`cvt.v_front_porch = cvt.vtotal - cvt.yres/cvt.interlace -`
373			`cvt.v_back_porch - cvt.vsync;`
374			`fb_cvt_print_name(&cvt);`
375			`fb_cvt_convert_to_mode(&cvt, mode);`
376
377			`return 0;`
378			`}`