xref: /openbmc/linux/drivers/video/fbdev/gxt4500.c (revision d9fd5a71)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Frame buffer device for IBM GXT4500P/6500P and GXT4000P/6000P
4  * display adaptors
5  *
6  * Copyright (C) 2006 Paul Mackerras, IBM Corp. <paulus@samba.org>
7  */
8 
9 #include <linux/kernel.h>
10 #include <linux/module.h>
11 #include <linux/fb.h>
12 #include <linux/console.h>
13 #include <linux/pci.h>
14 #include <linux/pci_ids.h>
15 #include <linux/delay.h>
16 #include <linux/string.h>
17 
18 #define PCI_DEVICE_ID_IBM_GXT4500P	0x21c
19 #define PCI_DEVICE_ID_IBM_GXT6500P	0x21b
20 #define PCI_DEVICE_ID_IBM_GXT4000P	0x16e
21 #define PCI_DEVICE_ID_IBM_GXT6000P	0x170
22 
23 /* GXT4500P registers */
24 
25 /* Registers in PCI config space */
26 #define CFG_ENDIAN0		0x40
27 
28 /* Misc control/status registers */
29 #define STATUS			0x1000
30 #define CTRL_REG0		0x1004
31 #define   CR0_HALT_DMA			0x4
32 #define   CR0_RASTER_RESET		0x8
33 #define   CR0_GEOM_RESET		0x10
34 #define   CR0_MEM_CTRLER_RESET		0x20
35 
36 /* Framebuffer control registers */
37 #define FB_AB_CTRL		0x1100
38 #define FB_CD_CTRL		0x1104
39 #define FB_WID_CTRL		0x1108
40 #define FB_Z_CTRL		0x110c
41 #define FB_VGA_CTRL		0x1110
42 #define REFRESH_AB_CTRL		0x1114
43 #define REFRESH_CD_CTRL		0x1118
44 #define FB_OVL_CTRL		0x111c
45 #define   FB_CTRL_TYPE			0x80000000
46 #define   FB_CTRL_WIDTH_MASK		0x007f0000
47 #define   FB_CTRL_WIDTH_SHIFT		16
48 #define   FB_CTRL_START_SEG_MASK	0x00003fff
49 
50 #define REFRESH_START		0x1098
51 #define REFRESH_SIZE		0x109c
52 
53 /* "Direct" framebuffer access registers */
54 #define DFA_FB_A		0x11e0
55 #define DFA_FB_B		0x11e4
56 #define DFA_FB_C		0x11e8
57 #define DFA_FB_D		0x11ec
58 #define   DFA_FB_ENABLE			0x80000000
59 #define   DFA_FB_BASE_MASK		0x03f00000
60 #define   DFA_FB_STRIDE_1k		0x00000000
61 #define   DFA_FB_STRIDE_2k		0x00000010
62 #define   DFA_FB_STRIDE_4k		0x00000020
63 #define   DFA_PIX_8BIT			0x00000000
64 #define   DFA_PIX_16BIT_565		0x00000001
65 #define   DFA_PIX_16BIT_1555		0x00000002
66 #define   DFA_PIX_24BIT			0x00000004
67 #define   DFA_PIX_32BIT			0x00000005
68 
69 /* maps DFA_PIX_* to pixel size in bytes */
70 static const unsigned char pixsize[] = {
71 	1, 2, 2, 2, 4, 4
72 };
73 
74 /* Display timing generator registers */
75 #define DTG_CONTROL		0x1900
76 #define   DTG_CTL_SCREEN_REFRESH	2
77 #define   DTG_CTL_ENABLE		1
78 #define DTG_HORIZ_EXTENT	0x1904
79 #define DTG_HORIZ_DISPLAY	0x1908
80 #define DTG_HSYNC_START		0x190c
81 #define DTG_HSYNC_END		0x1910
82 #define DTG_HSYNC_END_COMP	0x1914
83 #define DTG_VERT_EXTENT		0x1918
84 #define DTG_VERT_DISPLAY	0x191c
85 #define DTG_VSYNC_START		0x1920
86 #define DTG_VSYNC_END		0x1924
87 #define DTG_VERT_SHORT		0x1928
88 
89 /* PLL/RAMDAC registers */
90 #define DISP_CTL		0x402c
91 #define   DISP_CTL_OFF			2
92 #define SYNC_CTL		0x4034
93 #define   SYNC_CTL_SYNC_ON_RGB		1
94 #define   SYNC_CTL_SYNC_OFF		2
95 #define   SYNC_CTL_HSYNC_INV		8
96 #define   SYNC_CTL_VSYNC_INV		0x10
97 #define   SYNC_CTL_HSYNC_OFF		0x20
98 #define   SYNC_CTL_VSYNC_OFF		0x40
99 
100 #define PLL_M			0x4040
101 #define PLL_N			0x4044
102 #define PLL_POSTDIV		0x4048
103 #define PLL_C			0x404c
104 
105 /* Hardware cursor */
106 #define CURSOR_X		0x4078
107 #define CURSOR_Y		0x407c
108 #define CURSOR_HOTSPOT		0x4080
109 #define CURSOR_MODE		0x4084
110 #define   CURSOR_MODE_OFF		0
111 #define   CURSOR_MODE_4BPP		1
112 #define CURSOR_PIXMAP		0x5000
113 #define CURSOR_CMAP		0x7400
114 
115 /* Window attribute table */
116 #define WAT_FMT			0x4100
117 #define   WAT_FMT_24BIT			0
118 #define   WAT_FMT_16BIT_565		1
119 #define   WAT_FMT_16BIT_1555		2
120 #define   WAT_FMT_32BIT			3	/* 0 vs. 3 is a guess */
121 #define   WAT_FMT_8BIT_332		9
122 #define   WAT_FMT_8BIT			0xa
123 #define   WAT_FMT_NO_CMAP		4	/* ORd in to other values */
124 #define WAT_CMAP_OFFSET		0x4104		/* 4-bit value gets << 6 */
125 #define WAT_CTRL		0x4108
126 #define   WAT_CTRL_SEL_B		1	/* select B buffer if 1 */
127 #define   WAT_CTRL_NO_INC		2
128 #define WAT_GAMMA_CTRL		0x410c
129 #define   WAT_GAMMA_DISABLE		1	/* disables gamma cmap */
130 #define WAT_OVL_CTRL		0x430c		/* controls overlay */
131 
132 /* Indexed by DFA_PIX_* values */
133 static const unsigned char watfmt[] = {
134 	WAT_FMT_8BIT, WAT_FMT_16BIT_565, WAT_FMT_16BIT_1555, 0,
135 	WAT_FMT_24BIT, WAT_FMT_32BIT
136 };
137 
138 /* Colormap array; 1k entries of 4 bytes each */
139 #define CMAP			0x6000
140 
141 #define readreg(par, reg)	readl((par)->regs + (reg))
142 #define writereg(par, reg, val)	writel((val), (par)->regs + (reg))
143 
144 struct gxt4500_par {
145 	void __iomem *regs;
146 	int wc_cookie;
147 	int pixfmt;		/* pixel format, see DFA_PIX_* values */
148 
149 	/* PLL parameters */
150 	int refclk_ps;		/* ref clock period in picoseconds */
151 	int pll_m;		/* ref clock divisor */
152 	int pll_n;		/* VCO divisor */
153 	int pll_pd1;		/* first post-divisor */
154 	int pll_pd2;		/* second post-divisor */
155 
156 	u32 pseudo_palette[16];	/* used in color blits */
157 };
158 
159 /* mode requested by user */
160 static char *mode_option;
161 
162 /* default mode: 1280x1024 @ 60 Hz, 8 bpp */
163 static const struct fb_videomode defaultmode = {
164 	.refresh = 60,
165 	.xres = 1280,
166 	.yres = 1024,
167 	.pixclock = 9295,
168 	.left_margin = 248,
169 	.right_margin = 48,
170 	.upper_margin = 38,
171 	.lower_margin = 1,
172 	.hsync_len = 112,
173 	.vsync_len = 3,
174 	.vmode = FB_VMODE_NONINTERLACED
175 };
176 
177 /* List of supported cards */
178 enum gxt_cards {
179 	GXT4500P,
180 	GXT6500P,
181 	GXT4000P,
182 	GXT6000P
183 };
184 
185 /* Card-specific information */
186 static const struct cardinfo {
187 	int	refclk_ps;	/* period of PLL reference clock in ps */
188 	const char *cardname;
189 } cardinfo[] = {
190 	[GXT4500P] = { .refclk_ps = 9259, .cardname = "IBM GXT4500P" },
191 	[GXT6500P] = { .refclk_ps = 9259, .cardname = "IBM GXT6500P" },
192 	[GXT4000P] = { .refclk_ps = 40000, .cardname = "IBM GXT4000P" },
193 	[GXT6000P] = { .refclk_ps = 40000, .cardname = "IBM GXT6000P" },
194 };
195 
196 /*
197  * The refclk and VCO dividers appear to use a linear feedback shift
198  * register, which gets reloaded when it reaches a terminal value, at
199  * which point the divider output is toggled.  Thus one can obtain
200  * whatever divisor is required by putting the appropriate value into
201  * the reload register.  For a divisor of N, one puts the value from
202  * the LFSR sequence that comes N-1 places before the terminal value
203  * into the reload register.
204  */
205 
206 static const unsigned char mdivtab[] = {
207 /* 1 */		      0x3f, 0x00, 0x20, 0x10, 0x28, 0x14, 0x2a, 0x15, 0x0a,
208 /* 10 */	0x25, 0x32, 0x19, 0x0c, 0x26, 0x13, 0x09, 0x04, 0x22, 0x11,
209 /* 20 */	0x08, 0x24, 0x12, 0x29, 0x34, 0x1a, 0x2d, 0x36, 0x1b, 0x0d,
210 /* 30 */	0x06, 0x23, 0x31, 0x38, 0x1c, 0x2e, 0x17, 0x0b, 0x05, 0x02,
211 /* 40 */	0x21, 0x30, 0x18, 0x2c, 0x16, 0x2b, 0x35, 0x3a, 0x1d, 0x0e,
212 /* 50 */	0x27, 0x33, 0x39, 0x3c, 0x1e, 0x2f, 0x37, 0x3b, 0x3d, 0x3e,
213 /* 60 */	0x1f, 0x0f, 0x07, 0x03, 0x01,
214 };
215 
216 static const unsigned char ndivtab[] = {
217 /* 2 */		            0x00, 0x80, 0xc0, 0xe0, 0xf0, 0x78, 0xbc, 0x5e,
218 /* 10 */	0x2f, 0x17, 0x0b, 0x85, 0xc2, 0xe1, 0x70, 0x38, 0x9c, 0x4e,
219 /* 20 */	0xa7, 0xd3, 0xe9, 0xf4, 0xfa, 0xfd, 0xfe, 0x7f, 0xbf, 0xdf,
220 /* 30 */	0xef, 0x77, 0x3b, 0x1d, 0x8e, 0xc7, 0xe3, 0x71, 0xb8, 0xdc,
221 /* 40 */	0x6e, 0xb7, 0x5b, 0x2d, 0x16, 0x8b, 0xc5, 0xe2, 0xf1, 0xf8,
222 /* 50 */	0xfc, 0x7e, 0x3f, 0x9f, 0xcf, 0x67, 0xb3, 0xd9, 0x6c, 0xb6,
223 /* 60 */	0xdb, 0x6d, 0x36, 0x9b, 0x4d, 0x26, 0x13, 0x89, 0xc4, 0x62,
224 /* 70 */	0xb1, 0xd8, 0xec, 0xf6, 0xfb, 0x7d, 0xbe, 0x5f, 0xaf, 0x57,
225 /* 80 */	0x2b, 0x95, 0x4a, 0x25, 0x92, 0x49, 0xa4, 0x52, 0x29, 0x94,
226 /* 90 */	0xca, 0x65, 0xb2, 0x59, 0x2c, 0x96, 0xcb, 0xe5, 0xf2, 0x79,
227 /* 100 */	0x3c, 0x1e, 0x0f, 0x07, 0x83, 0x41, 0x20, 0x90, 0x48, 0x24,
228 /* 110 */	0x12, 0x09, 0x84, 0x42, 0xa1, 0x50, 0x28, 0x14, 0x8a, 0x45,
229 /* 120 */	0xa2, 0xd1, 0xe8, 0x74, 0xba, 0xdd, 0xee, 0xf7, 0x7b, 0x3d,
230 /* 130 */	0x9e, 0x4f, 0x27, 0x93, 0xc9, 0xe4, 0x72, 0x39, 0x1c, 0x0e,
231 /* 140 */	0x87, 0xc3, 0x61, 0x30, 0x18, 0x8c, 0xc6, 0x63, 0x31, 0x98,
232 /* 150 */	0xcc, 0xe6, 0x73, 0xb9, 0x5c, 0x2e, 0x97, 0x4b, 0xa5, 0xd2,
233 /* 160 */	0x69,
234 };
235 
236 static int calc_pll(int period_ps, struct gxt4500_par *par)
237 {
238 	int m, n, pdiv1, pdiv2, postdiv;
239 	int pll_period, best_error, t, intf;
240 
241 	/* only deal with range 5MHz - 300MHz */
242 	if (period_ps < 3333 || period_ps > 200000)
243 		return -1;
244 
245 	best_error = 1000000;
246 	for (pdiv1 = 1; pdiv1 <= 8; ++pdiv1) {
247 		for (pdiv2 = 1; pdiv2 <= pdiv1; ++pdiv2) {
248 			postdiv = pdiv1 * pdiv2;
249 			pll_period = DIV_ROUND_UP(period_ps, postdiv);
250 			/* keep pll in range 350..600 MHz */
251 			if (pll_period < 1666 || pll_period > 2857)
252 				continue;
253 			for (m = 1; m <= 64; ++m) {
254 				intf = m * par->refclk_ps;
255 				if (intf > 500000)
256 					break;
257 				n = intf * postdiv / period_ps;
258 				if (n < 3 || n > 160)
259 					continue;
260 				t = par->refclk_ps * m * postdiv / n;
261 				t -= period_ps;
262 				if (t >= 0 && t < best_error) {
263 					par->pll_m = m;
264 					par->pll_n = n;
265 					par->pll_pd1 = pdiv1;
266 					par->pll_pd2 = pdiv2;
267 					best_error = t;
268 				}
269 			}
270 		}
271 	}
272 	if (best_error == 1000000)
273 		return -1;
274 	return 0;
275 }
276 
277 static int calc_pixclock(struct gxt4500_par *par)
278 {
279 	return par->refclk_ps * par->pll_m * par->pll_pd1 * par->pll_pd2
280 		/ par->pll_n;
281 }
282 
283 static int gxt4500_var_to_par(struct fb_var_screeninfo *var,
284 			      struct gxt4500_par *par)
285 {
286 	if (var->xres + var->xoffset > var->xres_virtual ||
287 	    var->yres + var->yoffset > var->yres_virtual ||
288 	    var->xres_virtual > 4096)
289 		return -EINVAL;
290 	if ((var->vmode & FB_VMODE_MASK) != FB_VMODE_NONINTERLACED)
291 		return -EINVAL;
292 
293 	if (calc_pll(var->pixclock, par) < 0)
294 		return -EINVAL;
295 
296 	switch (var->bits_per_pixel) {
297 	case 32:
298 		if (var->transp.length)
299 			par->pixfmt = DFA_PIX_32BIT;
300 		else
301 			par->pixfmt = DFA_PIX_24BIT;
302 		break;
303 	case 24:
304 		par->pixfmt = DFA_PIX_24BIT;
305 		break;
306 	case 16:
307 		if (var->green.length == 5)
308 			par->pixfmt = DFA_PIX_16BIT_1555;
309 		else
310 			par->pixfmt = DFA_PIX_16BIT_565;
311 		break;
312 	case 8:
313 		par->pixfmt = DFA_PIX_8BIT;
314 		break;
315 	default:
316 		return -EINVAL;
317 	}
318 
319 	return 0;
320 }
321 
322 static const struct fb_bitfield eightbits = {0, 8};
323 static const struct fb_bitfield nobits = {0, 0};
324 
325 static void gxt4500_unpack_pixfmt(struct fb_var_screeninfo *var,
326 				  int pixfmt)
327 {
328 	var->bits_per_pixel = pixsize[pixfmt] * 8;
329 	var->red = eightbits;
330 	var->green = eightbits;
331 	var->blue = eightbits;
332 	var->transp = nobits;
333 
334 	switch (pixfmt) {
335 	case DFA_PIX_16BIT_565:
336 		var->red.length = 5;
337 		var->green.length = 6;
338 		var->blue.length = 5;
339 		break;
340 	case DFA_PIX_16BIT_1555:
341 		var->red.length = 5;
342 		var->green.length = 5;
343 		var->blue.length = 5;
344 		var->transp.length = 1;
345 		break;
346 	case DFA_PIX_32BIT:
347 		var->transp.length = 8;
348 		break;
349 	}
350 	if (pixfmt != DFA_PIX_8BIT) {
351 		var->blue.offset = 0;
352 		var->green.offset = var->blue.length;
353 		var->red.offset = var->green.offset + var->green.length;
354 		if (var->transp.length)
355 			var->transp.offset =
356 				var->red.offset + var->red.length;
357 	}
358 }
359 
360 static int gxt4500_check_var(struct fb_var_screeninfo *var,
361 			     struct fb_info *info)
362 {
363 	struct gxt4500_par par;
364 	int err;
365 
366 	par = *(struct gxt4500_par *)info->par;
367 	err = gxt4500_var_to_par(var, &par);
368 	if (!err) {
369 		var->pixclock = calc_pixclock(&par);
370 		gxt4500_unpack_pixfmt(var, par.pixfmt);
371 	}
372 	return err;
373 }
374 
375 static int gxt4500_set_par(struct fb_info *info)
376 {
377 	struct gxt4500_par *par = info->par;
378 	struct fb_var_screeninfo *var = &info->var;
379 	int err;
380 	u32 ctrlreg, tmp;
381 	unsigned int dfa_ctl, pixfmt, stride;
382 	unsigned int wid_tiles, i;
383 	unsigned int prefetch_pix, htot;
384 	struct gxt4500_par save_par;
385 
386 	save_par = *par;
387 	err = gxt4500_var_to_par(var, par);
388 	if (err) {
389 		*par = save_par;
390 		return err;
391 	}
392 
393 	/* turn off DTG for now */
394 	ctrlreg = readreg(par, DTG_CONTROL);
395 	ctrlreg &= ~(DTG_CTL_ENABLE | DTG_CTL_SCREEN_REFRESH);
396 	writereg(par, DTG_CONTROL, ctrlreg);
397 
398 	/* set PLL registers */
399 	tmp = readreg(par, PLL_C) & ~0x7f;
400 	if (par->pll_n < 38)
401 		tmp |= 0x29;
402 	if (par->pll_n < 69)
403 		tmp |= 0x35;
404 	else if (par->pll_n < 100)
405 		tmp |= 0x76;
406 	else
407 		tmp |= 0x7e;
408 	writereg(par, PLL_C, tmp);
409 	writereg(par, PLL_M, mdivtab[par->pll_m - 1]);
410 	writereg(par, PLL_N, ndivtab[par->pll_n - 2]);
411 	tmp = ((8 - par->pll_pd2) << 3) | (8 - par->pll_pd1);
412 	if (par->pll_pd1 == 8 || par->pll_pd2 == 8) {
413 		/* work around erratum */
414 		writereg(par, PLL_POSTDIV, tmp | 0x9);
415 		udelay(1);
416 	}
417 	writereg(par, PLL_POSTDIV, tmp);
418 	msleep(20);
419 
420 	/* turn off hardware cursor */
421 	writereg(par, CURSOR_MODE, CURSOR_MODE_OFF);
422 
423 	/* reset raster engine */
424 	writereg(par, CTRL_REG0, CR0_RASTER_RESET | (CR0_RASTER_RESET << 16));
425 	udelay(10);
426 	writereg(par, CTRL_REG0, CR0_RASTER_RESET << 16);
427 
428 	/* set display timing generator registers */
429 	htot = var->xres + var->left_margin + var->right_margin +
430 		var->hsync_len;
431 	writereg(par, DTG_HORIZ_EXTENT, htot - 1);
432 	writereg(par, DTG_HORIZ_DISPLAY, var->xres - 1);
433 	writereg(par, DTG_HSYNC_START, var->xres + var->right_margin - 1);
434 	writereg(par, DTG_HSYNC_END,
435 		 var->xres + var->right_margin + var->hsync_len - 1);
436 	writereg(par, DTG_HSYNC_END_COMP,
437 		 var->xres + var->right_margin + var->hsync_len - 1);
438 	writereg(par, DTG_VERT_EXTENT,
439 		 var->yres + var->upper_margin + var->lower_margin +
440 		 var->vsync_len - 1);
441 	writereg(par, DTG_VERT_DISPLAY, var->yres - 1);
442 	writereg(par, DTG_VSYNC_START, var->yres + var->lower_margin - 1);
443 	writereg(par, DTG_VSYNC_END,
444 		 var->yres + var->lower_margin + var->vsync_len - 1);
445 	prefetch_pix = 3300000 / var->pixclock;
446 	if (prefetch_pix >= htot)
447 		prefetch_pix = htot - 1;
448 	writereg(par, DTG_VERT_SHORT, htot - prefetch_pix - 1);
449 	ctrlreg |= DTG_CTL_ENABLE | DTG_CTL_SCREEN_REFRESH;
450 	writereg(par, DTG_CONTROL, ctrlreg);
451 
452 	/* calculate stride in DFA aperture */
453 	if (var->xres_virtual > 2048) {
454 		stride = 4096;
455 		dfa_ctl = DFA_FB_STRIDE_4k;
456 	} else if (var->xres_virtual > 1024) {
457 		stride = 2048;
458 		dfa_ctl = DFA_FB_STRIDE_2k;
459 	} else {
460 		stride = 1024;
461 		dfa_ctl = DFA_FB_STRIDE_1k;
462 	}
463 
464 	/* Set up framebuffer definition */
465 	wid_tiles = (var->xres_virtual + 63) >> 6;
466 
467 	/* XXX add proper FB allocation here someday */
468 	writereg(par, FB_AB_CTRL, FB_CTRL_TYPE | (wid_tiles << 16) | 0);
469 	writereg(par, REFRESH_AB_CTRL, FB_CTRL_TYPE | (wid_tiles << 16) | 0);
470 	writereg(par, FB_CD_CTRL, FB_CTRL_TYPE | (wid_tiles << 16) | 0);
471 	writereg(par, REFRESH_CD_CTRL, FB_CTRL_TYPE | (wid_tiles << 16) | 0);
472 	writereg(par, REFRESH_START, (var->xoffset << 16) | var->yoffset);
473 	writereg(par, REFRESH_SIZE, (var->xres << 16) | var->yres);
474 
475 	/* Set up framebuffer access by CPU */
476 
477 	pixfmt = par->pixfmt;
478 	dfa_ctl |= DFA_FB_ENABLE | pixfmt;
479 	writereg(par, DFA_FB_A, dfa_ctl);
480 
481 	/*
482 	 * Set up window attribute table.
483 	 * We set all WAT entries the same so it doesn't matter what the
484 	 * window ID (WID) plane contains.
485 	 */
486 	for (i = 0; i < 32; ++i) {
487 		writereg(par, WAT_FMT + (i << 4), watfmt[pixfmt]);
488 		writereg(par, WAT_CMAP_OFFSET + (i << 4), 0);
489 		writereg(par, WAT_CTRL + (i << 4), 0);
490 		writereg(par, WAT_GAMMA_CTRL + (i << 4), WAT_GAMMA_DISABLE);
491 	}
492 
493 	/* Set sync polarity etc. */
494 	ctrlreg = readreg(par, SYNC_CTL) &
495 		~(SYNC_CTL_SYNC_ON_RGB | SYNC_CTL_HSYNC_INV |
496 		  SYNC_CTL_VSYNC_INV);
497 	if (var->sync & FB_SYNC_ON_GREEN)
498 		ctrlreg |= SYNC_CTL_SYNC_ON_RGB;
499 	if (!(var->sync & FB_SYNC_HOR_HIGH_ACT))
500 		ctrlreg |= SYNC_CTL_HSYNC_INV;
501 	if (!(var->sync & FB_SYNC_VERT_HIGH_ACT))
502 		ctrlreg |= SYNC_CTL_VSYNC_INV;
503 	writereg(par, SYNC_CTL, ctrlreg);
504 
505 	info->fix.line_length = stride * pixsize[pixfmt];
506 	info->fix.visual = (pixfmt == DFA_PIX_8BIT)? FB_VISUAL_PSEUDOCOLOR:
507 		FB_VISUAL_DIRECTCOLOR;
508 
509 	return 0;
510 }
511 
512 static int gxt4500_setcolreg(unsigned int reg, unsigned int red,
513 			     unsigned int green, unsigned int blue,
514 			     unsigned int transp, struct fb_info *info)
515 {
516 	u32 cmap_entry;
517 	struct gxt4500_par *par = info->par;
518 
519 	if (reg > 1023)
520 		return 1;
521 	cmap_entry = ((transp & 0xff00) << 16) | ((red & 0xff00) << 8) |
522 		(green & 0xff00) | (blue >> 8);
523 	writereg(par, CMAP + reg * 4, cmap_entry);
524 
525 	if (reg < 16 && par->pixfmt != DFA_PIX_8BIT) {
526 		u32 *pal = info->pseudo_palette;
527 		u32 val = reg;
528 		switch (par->pixfmt) {
529 		case DFA_PIX_16BIT_565:
530 			val |= (reg << 11) | (reg << 5);
531 			break;
532 		case DFA_PIX_16BIT_1555:
533 			val |= (reg << 10) | (reg << 5);
534 			break;
535 		case DFA_PIX_32BIT:
536 			val |= (reg << 24);
537 			fallthrough;
538 		case DFA_PIX_24BIT:
539 			val |= (reg << 16) | (reg << 8);
540 			break;
541 		}
542 		pal[reg] = val;
543 	}
544 
545 	return 0;
546 }
547 
548 static int gxt4500_pan_display(struct fb_var_screeninfo *var,
549 			       struct fb_info *info)
550 {
551 	struct gxt4500_par *par = info->par;
552 
553 	if (var->xoffset & 7)
554 		return -EINVAL;
555 	if (var->xoffset + info->var.xres > info->var.xres_virtual ||
556 	    var->yoffset + info->var.yres > info->var.yres_virtual)
557 		return -EINVAL;
558 
559 	writereg(par, REFRESH_START, (var->xoffset << 16) | var->yoffset);
560 	return 0;
561 }
562 
563 static int gxt4500_blank(int blank, struct fb_info *info)
564 {
565 	struct gxt4500_par *par = info->par;
566 	int ctrl, dctl;
567 
568 	ctrl = readreg(par, SYNC_CTL);
569 	ctrl &= ~(SYNC_CTL_SYNC_OFF | SYNC_CTL_HSYNC_OFF | SYNC_CTL_VSYNC_OFF);
570 	dctl = readreg(par, DISP_CTL);
571 	dctl |= DISP_CTL_OFF;
572 	switch (blank) {
573 	case FB_BLANK_UNBLANK:
574 		dctl &= ~DISP_CTL_OFF;
575 		break;
576 	case FB_BLANK_POWERDOWN:
577 		ctrl |= SYNC_CTL_SYNC_OFF;
578 		break;
579 	case FB_BLANK_HSYNC_SUSPEND:
580 		ctrl |= SYNC_CTL_HSYNC_OFF;
581 		break;
582 	case FB_BLANK_VSYNC_SUSPEND:
583 		ctrl |= SYNC_CTL_VSYNC_OFF;
584 		break;
585 	default: ;
586 	}
587 	writereg(par, SYNC_CTL, ctrl);
588 	writereg(par, DISP_CTL, dctl);
589 
590 	return 0;
591 }
592 
593 static const struct fb_fix_screeninfo gxt4500_fix = {
594 	.id = "IBM GXT4500P",
595 	.type = FB_TYPE_PACKED_PIXELS,
596 	.visual = FB_VISUAL_PSEUDOCOLOR,
597 	.xpanstep = 8,
598 	.ypanstep = 1,
599 	.mmio_len = 0x20000,
600 };
601 
602 static const struct fb_ops gxt4500_ops = {
603 	.owner = THIS_MODULE,
604 	.fb_check_var = gxt4500_check_var,
605 	.fb_set_par = gxt4500_set_par,
606 	.fb_setcolreg = gxt4500_setcolreg,
607 	.fb_pan_display = gxt4500_pan_display,
608 	.fb_blank = gxt4500_blank,
609 	.fb_fillrect = cfb_fillrect,
610 	.fb_copyarea = cfb_copyarea,
611 	.fb_imageblit = cfb_imageblit,
612 };
613 
614 /* PCI functions */
615 static int gxt4500_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
616 {
617 	int err;
618 	unsigned long reg_phys, fb_phys;
619 	struct gxt4500_par *par;
620 	struct fb_info *info;
621 	struct fb_var_screeninfo var;
622 	enum gxt_cards cardtype;
623 
624 	err = pci_enable_device(pdev);
625 	if (err) {
626 		dev_err(&pdev->dev, "gxt4500: cannot enable PCI device: %d\n",
627 			err);
628 		return err;
629 	}
630 
631 	reg_phys = pci_resource_start(pdev, 0);
632 	if (!request_mem_region(reg_phys, pci_resource_len(pdev, 0),
633 				"gxt4500 regs")) {
634 		dev_err(&pdev->dev, "gxt4500: cannot get registers\n");
635 		goto err_nodev;
636 	}
637 
638 	fb_phys = pci_resource_start(pdev, 1);
639 	if (!request_mem_region(fb_phys, pci_resource_len(pdev, 1),
640 				"gxt4500 FB")) {
641 		dev_err(&pdev->dev, "gxt4500: cannot get framebuffer\n");
642 		goto err_free_regs;
643 	}
644 
645 	info = framebuffer_alloc(sizeof(struct gxt4500_par), &pdev->dev);
646 	if (!info)
647 		goto err_free_fb;
648 
649 	par = info->par;
650 	cardtype = ent->driver_data;
651 	par->refclk_ps = cardinfo[cardtype].refclk_ps;
652 	info->fix = gxt4500_fix;
653 	strlcpy(info->fix.id, cardinfo[cardtype].cardname,
654 		sizeof(info->fix.id));
655 	info->pseudo_palette = par->pseudo_palette;
656 
657 	info->fix.mmio_start = reg_phys;
658 	par->regs = pci_ioremap_bar(pdev, 0);
659 	if (!par->regs) {
660 		dev_err(&pdev->dev, "gxt4500: cannot map registers\n");
661 		goto err_free_all;
662 	}
663 
664 	info->fix.smem_start = fb_phys;
665 	info->fix.smem_len = pci_resource_len(pdev, 1);
666 	info->screen_base = pci_ioremap_wc_bar(pdev, 1);
667 	if (!info->screen_base) {
668 		dev_err(&pdev->dev, "gxt4500: cannot map framebuffer\n");
669 		goto err_unmap_regs;
670 	}
671 
672 	pci_set_drvdata(pdev, info);
673 
674 	par->wc_cookie = arch_phys_wc_add(info->fix.smem_start,
675 					  info->fix.smem_len);
676 
677 #ifdef __BIG_ENDIAN
678 	/* Set byte-swapping for DFA aperture for all pixel sizes */
679 	pci_write_config_dword(pdev, CFG_ENDIAN0, 0x333300);
680 #else /* __LITTLE_ENDIAN */
681 	/* not sure what this means but fgl23 driver does that */
682 	pci_write_config_dword(pdev, CFG_ENDIAN0, 0x2300);
683 /*	pci_write_config_dword(pdev, CFG_ENDIAN0 + 4, 0x400000);*/
684 	pci_write_config_dword(pdev, CFG_ENDIAN0 + 8, 0x98530000);
685 #endif
686 
687 	info->fbops = &gxt4500_ops;
688 	info->flags = FBINFO_FLAG_DEFAULT | FBINFO_HWACCEL_XPAN |
689 					    FBINFO_HWACCEL_YPAN;
690 
691 	err = fb_alloc_cmap(&info->cmap, 256, 0);
692 	if (err) {
693 		dev_err(&pdev->dev, "gxt4500: cannot allocate cmap\n");
694 		goto err_unmap_all;
695 	}
696 
697 	gxt4500_blank(FB_BLANK_UNBLANK, info);
698 
699 	if (!fb_find_mode(&var, info, mode_option, NULL, 0, &defaultmode, 8)) {
700 		dev_err(&pdev->dev, "gxt4500: cannot find valid video mode\n");
701 		goto err_free_cmap;
702 	}
703 	info->var = var;
704 	if (gxt4500_set_par(info)) {
705 		printk(KERN_ERR "gxt4500: cannot set video mode\n");
706 		goto err_free_cmap;
707 	}
708 
709 	if (register_framebuffer(info) < 0) {
710 		dev_err(&pdev->dev, "gxt4500: cannot register framebuffer\n");
711 		goto err_free_cmap;
712 	}
713 	fb_info(info, "%s frame buffer device\n", info->fix.id);
714 
715 	return 0;
716 
717  err_free_cmap:
718 	fb_dealloc_cmap(&info->cmap);
719  err_unmap_all:
720 	iounmap(info->screen_base);
721  err_unmap_regs:
722 	iounmap(par->regs);
723  err_free_all:
724 	framebuffer_release(info);
725  err_free_fb:
726 	release_mem_region(fb_phys, pci_resource_len(pdev, 1));
727  err_free_regs:
728 	release_mem_region(reg_phys, pci_resource_len(pdev, 0));
729  err_nodev:
730 	return -ENODEV;
731 }
732 
733 static void gxt4500_remove(struct pci_dev *pdev)
734 {
735 	struct fb_info *info = pci_get_drvdata(pdev);
736 	struct gxt4500_par *par;
737 
738 	if (!info)
739 		return;
740 	par = info->par;
741 	unregister_framebuffer(info);
742 	arch_phys_wc_del(par->wc_cookie);
743 	fb_dealloc_cmap(&info->cmap);
744 	iounmap(par->regs);
745 	iounmap(info->screen_base);
746 	release_mem_region(pci_resource_start(pdev, 0),
747 			   pci_resource_len(pdev, 0));
748 	release_mem_region(pci_resource_start(pdev, 1),
749 			   pci_resource_len(pdev, 1));
750 	framebuffer_release(info);
751 }
752 
753 /* supported chipsets */
754 static const struct pci_device_id gxt4500_pci_tbl[] = {
755 	{ PCI_DEVICE(PCI_VENDOR_ID_IBM, PCI_DEVICE_ID_IBM_GXT4500P),
756 	  .driver_data = GXT4500P },
757 	{ PCI_DEVICE(PCI_VENDOR_ID_IBM, PCI_DEVICE_ID_IBM_GXT6500P),
758 	  .driver_data = GXT6500P },
759 	{ PCI_DEVICE(PCI_VENDOR_ID_IBM, PCI_DEVICE_ID_IBM_GXT4000P),
760 	  .driver_data = GXT4000P },
761 	{ PCI_DEVICE(PCI_VENDOR_ID_IBM, PCI_DEVICE_ID_IBM_GXT6000P),
762 	  .driver_data = GXT6000P },
763 	{ 0 }
764 };
765 
766 MODULE_DEVICE_TABLE(pci, gxt4500_pci_tbl);
767 
768 static struct pci_driver gxt4500_driver = {
769 	.name = "gxt4500",
770 	.id_table = gxt4500_pci_tbl,
771 	.probe = gxt4500_probe,
772 	.remove = gxt4500_remove,
773 };
774 
775 static int gxt4500_init(void)
776 {
777 #ifndef MODULE
778 	if (fb_get_options("gxt4500", &mode_option))
779 		return -ENODEV;
780 #endif
781 
782 	return pci_register_driver(&gxt4500_driver);
783 }
784 module_init(gxt4500_init);
785 
786 static void __exit gxt4500_exit(void)
787 {
788 	pci_unregister_driver(&gxt4500_driver);
789 }
790 module_exit(gxt4500_exit);
791 
792 MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
793 MODULE_DESCRIPTION("FBDev driver for IBM GXT4500P/6500P and GXT4000P/6000P");
794 MODULE_LICENSE("GPL");
795 module_param(mode_option, charp, 0);
796 MODULE_PARM_DESC(mode_option, "Specify resolution as \"<xres>x<yres>[-<bpp>][@<refresh>]\"");
797