xref: /openbmc/linux/drivers/video/fbdev/gxt4500.c (revision b1c3d2be)
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/aperture.h>
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/fb.h>
13 #include <linux/console.h>
14 #include <linux/pci.h>
15 #include <linux/pci_ids.h>
16 #include <linux/delay.h>
17 #include <linux/string.h>
18 
19 #define PCI_DEVICE_ID_IBM_GXT4500P	0x21c
20 #define PCI_DEVICE_ID_IBM_GXT6500P	0x21b
21 #define PCI_DEVICE_ID_IBM_GXT4000P	0x16e
22 #define PCI_DEVICE_ID_IBM_GXT6000P	0x170
23 
24 /* GXT4500P registers */
25 
26 /* Registers in PCI config space */
27 #define CFG_ENDIAN0		0x40
28 
29 /* Misc control/status registers */
30 #define STATUS			0x1000
31 #define CTRL_REG0		0x1004
32 #define   CR0_HALT_DMA			0x4
33 #define   CR0_RASTER_RESET		0x8
34 #define   CR0_GEOM_RESET		0x10
35 #define   CR0_MEM_CTRLER_RESET		0x20
36 
37 /* Framebuffer control registers */
38 #define FB_AB_CTRL		0x1100
39 #define FB_CD_CTRL		0x1104
40 #define FB_WID_CTRL		0x1108
41 #define FB_Z_CTRL		0x110c
42 #define FB_VGA_CTRL		0x1110
43 #define REFRESH_AB_CTRL		0x1114
44 #define REFRESH_CD_CTRL		0x1118
45 #define FB_OVL_CTRL		0x111c
46 #define   FB_CTRL_TYPE			0x80000000
47 #define   FB_CTRL_WIDTH_MASK		0x007f0000
48 #define   FB_CTRL_WIDTH_SHIFT		16
49 #define   FB_CTRL_START_SEG_MASK	0x00003fff
50 
51 #define REFRESH_START		0x1098
52 #define REFRESH_SIZE		0x109c
53 
54 /* "Direct" framebuffer access registers */
55 #define DFA_FB_A		0x11e0
56 #define DFA_FB_B		0x11e4
57 #define DFA_FB_C		0x11e8
58 #define DFA_FB_D		0x11ec
59 #define   DFA_FB_ENABLE			0x80000000
60 #define   DFA_FB_BASE_MASK		0x03f00000
61 #define   DFA_FB_STRIDE_1k		0x00000000
62 #define   DFA_FB_STRIDE_2k		0x00000010
63 #define   DFA_FB_STRIDE_4k		0x00000020
64 #define   DFA_PIX_8BIT			0x00000000
65 #define   DFA_PIX_16BIT_565		0x00000001
66 #define   DFA_PIX_16BIT_1555		0x00000002
67 #define   DFA_PIX_24BIT			0x00000004
68 #define   DFA_PIX_32BIT			0x00000005
69 
70 /* maps DFA_PIX_* to pixel size in bytes */
71 static const unsigned char pixsize[] = {
72 	1, 2, 2, 2, 4, 4
73 };
74 
75 /* Display timing generator registers */
76 #define DTG_CONTROL		0x1900
77 #define   DTG_CTL_SCREEN_REFRESH	2
78 #define   DTG_CTL_ENABLE		1
79 #define DTG_HORIZ_EXTENT	0x1904
80 #define DTG_HORIZ_DISPLAY	0x1908
81 #define DTG_HSYNC_START		0x190c
82 #define DTG_HSYNC_END		0x1910
83 #define DTG_HSYNC_END_COMP	0x1914
84 #define DTG_VERT_EXTENT		0x1918
85 #define DTG_VERT_DISPLAY	0x191c
86 #define DTG_VSYNC_START		0x1920
87 #define DTG_VSYNC_END		0x1924
88 #define DTG_VERT_SHORT		0x1928
89 
90 /* PLL/RAMDAC registers */
91 #define DISP_CTL		0x402c
92 #define   DISP_CTL_OFF			2
93 #define SYNC_CTL		0x4034
94 #define   SYNC_CTL_SYNC_ON_RGB		1
95 #define   SYNC_CTL_SYNC_OFF		2
96 #define   SYNC_CTL_HSYNC_INV		8
97 #define   SYNC_CTL_VSYNC_INV		0x10
98 #define   SYNC_CTL_HSYNC_OFF		0x20
99 #define   SYNC_CTL_VSYNC_OFF		0x40
100 
101 #define PLL_M			0x4040
102 #define PLL_N			0x4044
103 #define PLL_POSTDIV		0x4048
104 #define PLL_C			0x404c
105 
106 /* Hardware cursor */
107 #define CURSOR_X		0x4078
108 #define CURSOR_Y		0x407c
109 #define CURSOR_HOTSPOT		0x4080
110 #define CURSOR_MODE		0x4084
111 #define   CURSOR_MODE_OFF		0
112 #define   CURSOR_MODE_4BPP		1
113 #define CURSOR_PIXMAP		0x5000
114 #define CURSOR_CMAP		0x7400
115 
116 /* Window attribute table */
117 #define WAT_FMT			0x4100
118 #define   WAT_FMT_24BIT			0
119 #define   WAT_FMT_16BIT_565		1
120 #define   WAT_FMT_16BIT_1555		2
121 #define   WAT_FMT_32BIT			3	/* 0 vs. 3 is a guess */
122 #define   WAT_FMT_8BIT_332		9
123 #define   WAT_FMT_8BIT			0xa
124 #define   WAT_FMT_NO_CMAP		4	/* ORd in to other values */
125 #define WAT_CMAP_OFFSET		0x4104		/* 4-bit value gets << 6 */
126 #define WAT_CTRL		0x4108
127 #define   WAT_CTRL_SEL_B		1	/* select B buffer if 1 */
128 #define   WAT_CTRL_NO_INC		2
129 #define WAT_GAMMA_CTRL		0x410c
130 #define   WAT_GAMMA_DISABLE		1	/* disables gamma cmap */
131 #define WAT_OVL_CTRL		0x430c		/* controls overlay */
132 
133 /* Indexed by DFA_PIX_* values */
134 static const unsigned char watfmt[] = {
135 	WAT_FMT_8BIT, WAT_FMT_16BIT_565, WAT_FMT_16BIT_1555, 0,
136 	WAT_FMT_24BIT, WAT_FMT_32BIT
137 };
138 
139 /* Colormap array; 1k entries of 4 bytes each */
140 #define CMAP			0x6000
141 
142 #define readreg(par, reg)	readl((par)->regs + (reg))
143 #define writereg(par, reg, val)	writel((val), (par)->regs + (reg))
144 
145 struct gxt4500_par {
146 	void __iomem *regs;
147 	int wc_cookie;
148 	int pixfmt;		/* pixel format, see DFA_PIX_* values */
149 
150 	/* PLL parameters */
151 	int refclk_ps;		/* ref clock period in picoseconds */
152 	int pll_m;		/* ref clock divisor */
153 	int pll_n;		/* VCO divisor */
154 	int pll_pd1;		/* first post-divisor */
155 	int pll_pd2;		/* second post-divisor */
156 
157 	u32 pseudo_palette[16];	/* used in color blits */
158 };
159 
160 /* mode requested by user */
161 static char *mode_option;
162 
163 /* default mode: 1280x1024 @ 60 Hz, 8 bpp */
164 static const struct fb_videomode defaultmode = {
165 	.refresh = 60,
166 	.xres = 1280,
167 	.yres = 1024,
168 	.pixclock = 9295,
169 	.left_margin = 248,
170 	.right_margin = 48,
171 	.upper_margin = 38,
172 	.lower_margin = 1,
173 	.hsync_len = 112,
174 	.vsync_len = 3,
175 	.vmode = FB_VMODE_NONINTERLACED
176 };
177 
178 /* List of supported cards */
179 enum gxt_cards {
180 	GXT4500P,
181 	GXT6500P,
182 	GXT4000P,
183 	GXT6000P
184 };
185 
186 /* Card-specific information */
187 static const struct cardinfo {
188 	int	refclk_ps;	/* period of PLL reference clock in ps */
189 	const char *cardname;
190 } cardinfo[] = {
191 	[GXT4500P] = { .refclk_ps = 9259, .cardname = "IBM GXT4500P" },
192 	[GXT6500P] = { .refclk_ps = 9259, .cardname = "IBM GXT6500P" },
193 	[GXT4000P] = { .refclk_ps = 40000, .cardname = "IBM GXT4000P" },
194 	[GXT6000P] = { .refclk_ps = 40000, .cardname = "IBM GXT6000P" },
195 };
196 
197 /*
198  * The refclk and VCO dividers appear to use a linear feedback shift
199  * register, which gets reloaded when it reaches a terminal value, at
200  * which point the divider output is toggled.  Thus one can obtain
201  * whatever divisor is required by putting the appropriate value into
202  * the reload register.  For a divisor of N, one puts the value from
203  * the LFSR sequence that comes N-1 places before the terminal value
204  * into the reload register.
205  */
206 
207 static const unsigned char mdivtab[] = {
208 /* 1 */		      0x3f, 0x00, 0x20, 0x10, 0x28, 0x14, 0x2a, 0x15, 0x0a,
209 /* 10 */	0x25, 0x32, 0x19, 0x0c, 0x26, 0x13, 0x09, 0x04, 0x22, 0x11,
210 /* 20 */	0x08, 0x24, 0x12, 0x29, 0x34, 0x1a, 0x2d, 0x36, 0x1b, 0x0d,
211 /* 30 */	0x06, 0x23, 0x31, 0x38, 0x1c, 0x2e, 0x17, 0x0b, 0x05, 0x02,
212 /* 40 */	0x21, 0x30, 0x18, 0x2c, 0x16, 0x2b, 0x35, 0x3a, 0x1d, 0x0e,
213 /* 50 */	0x27, 0x33, 0x39, 0x3c, 0x1e, 0x2f, 0x37, 0x3b, 0x3d, 0x3e,
214 /* 60 */	0x1f, 0x0f, 0x07, 0x03, 0x01,
215 };
216 
217 static const unsigned char ndivtab[] = {
218 /* 2 */		            0x00, 0x80, 0xc0, 0xe0, 0xf0, 0x78, 0xbc, 0x5e,
219 /* 10 */	0x2f, 0x17, 0x0b, 0x85, 0xc2, 0xe1, 0x70, 0x38, 0x9c, 0x4e,
220 /* 20 */	0xa7, 0xd3, 0xe9, 0xf4, 0xfa, 0xfd, 0xfe, 0x7f, 0xbf, 0xdf,
221 /* 30 */	0xef, 0x77, 0x3b, 0x1d, 0x8e, 0xc7, 0xe3, 0x71, 0xb8, 0xdc,
222 /* 40 */	0x6e, 0xb7, 0x5b, 0x2d, 0x16, 0x8b, 0xc5, 0xe2, 0xf1, 0xf8,
223 /* 50 */	0xfc, 0x7e, 0x3f, 0x9f, 0xcf, 0x67, 0xb3, 0xd9, 0x6c, 0xb6,
224 /* 60 */	0xdb, 0x6d, 0x36, 0x9b, 0x4d, 0x26, 0x13, 0x89, 0xc4, 0x62,
225 /* 70 */	0xb1, 0xd8, 0xec, 0xf6, 0xfb, 0x7d, 0xbe, 0x5f, 0xaf, 0x57,
226 /* 80 */	0x2b, 0x95, 0x4a, 0x25, 0x92, 0x49, 0xa4, 0x52, 0x29, 0x94,
227 /* 90 */	0xca, 0x65, 0xb2, 0x59, 0x2c, 0x96, 0xcb, 0xe5, 0xf2, 0x79,
228 /* 100 */	0x3c, 0x1e, 0x0f, 0x07, 0x83, 0x41, 0x20, 0x90, 0x48, 0x24,
229 /* 110 */	0x12, 0x09, 0x84, 0x42, 0xa1, 0x50, 0x28, 0x14, 0x8a, 0x45,
230 /* 120 */	0xa2, 0xd1, 0xe8, 0x74, 0xba, 0xdd, 0xee, 0xf7, 0x7b, 0x3d,
231 /* 130 */	0x9e, 0x4f, 0x27, 0x93, 0xc9, 0xe4, 0x72, 0x39, 0x1c, 0x0e,
232 /* 140 */	0x87, 0xc3, 0x61, 0x30, 0x18, 0x8c, 0xc6, 0x63, 0x31, 0x98,
233 /* 150 */	0xcc, 0xe6, 0x73, 0xb9, 0x5c, 0x2e, 0x97, 0x4b, 0xa5, 0xd2,
234 /* 160 */	0x69,
235 };
236 
237 static int calc_pll(int period_ps, struct gxt4500_par *par)
238 {
239 	int m, n, pdiv1, pdiv2, postdiv;
240 	int pll_period, best_error, t, intf;
241 
242 	/* only deal with range 5MHz - 300MHz */
243 	if (period_ps < 3333 || period_ps > 200000)
244 		return -1;
245 
246 	best_error = 1000000;
247 	for (pdiv1 = 1; pdiv1 <= 8; ++pdiv1) {
248 		for (pdiv2 = 1; pdiv2 <= pdiv1; ++pdiv2) {
249 			postdiv = pdiv1 * pdiv2;
250 			pll_period = DIV_ROUND_UP(period_ps, postdiv);
251 			/* keep pll in range 350..600 MHz */
252 			if (pll_period < 1666 || pll_period > 2857)
253 				continue;
254 			for (m = 1; m <= 64; ++m) {
255 				intf = m * par->refclk_ps;
256 				if (intf > 500000)
257 					break;
258 				n = intf * postdiv / period_ps;
259 				if (n < 3 || n > 160)
260 					continue;
261 				t = par->refclk_ps * m * postdiv / n;
262 				t -= period_ps;
263 				if (t >= 0 && t < best_error) {
264 					par->pll_m = m;
265 					par->pll_n = n;
266 					par->pll_pd1 = pdiv1;
267 					par->pll_pd2 = pdiv2;
268 					best_error = t;
269 				}
270 			}
271 		}
272 	}
273 	if (best_error == 1000000)
274 		return -1;
275 	return 0;
276 }
277 
278 static int calc_pixclock(struct gxt4500_par *par)
279 {
280 	return par->refclk_ps * par->pll_m * par->pll_pd1 * par->pll_pd2
281 		/ par->pll_n;
282 }
283 
284 static int gxt4500_var_to_par(struct fb_var_screeninfo *var,
285 			      struct gxt4500_par *par)
286 {
287 	if (var->xres + var->xoffset > var->xres_virtual ||
288 	    var->yres + var->yoffset > var->yres_virtual ||
289 	    var->xres_virtual > 4096)
290 		return -EINVAL;
291 	if ((var->vmode & FB_VMODE_MASK) != FB_VMODE_NONINTERLACED)
292 		return -EINVAL;
293 
294 	if (calc_pll(var->pixclock, par) < 0)
295 		return -EINVAL;
296 
297 	switch (var->bits_per_pixel) {
298 	case 32:
299 		if (var->transp.length)
300 			par->pixfmt = DFA_PIX_32BIT;
301 		else
302 			par->pixfmt = DFA_PIX_24BIT;
303 		break;
304 	case 24:
305 		par->pixfmt = DFA_PIX_24BIT;
306 		break;
307 	case 16:
308 		if (var->green.length == 5)
309 			par->pixfmt = DFA_PIX_16BIT_1555;
310 		else
311 			par->pixfmt = DFA_PIX_16BIT_565;
312 		break;
313 	case 8:
314 		par->pixfmt = DFA_PIX_8BIT;
315 		break;
316 	default:
317 		return -EINVAL;
318 	}
319 
320 	return 0;
321 }
322 
323 static const struct fb_bitfield eightbits = {0, 8};
324 static const struct fb_bitfield nobits = {0, 0};
325 
326 static void gxt4500_unpack_pixfmt(struct fb_var_screeninfo *var,
327 				  int pixfmt)
328 {
329 	var->bits_per_pixel = pixsize[pixfmt] * 8;
330 	var->red = eightbits;
331 	var->green = eightbits;
332 	var->blue = eightbits;
333 	var->transp = nobits;
334 
335 	switch (pixfmt) {
336 	case DFA_PIX_16BIT_565:
337 		var->red.length = 5;
338 		var->green.length = 6;
339 		var->blue.length = 5;
340 		break;
341 	case DFA_PIX_16BIT_1555:
342 		var->red.length = 5;
343 		var->green.length = 5;
344 		var->blue.length = 5;
345 		var->transp.length = 1;
346 		break;
347 	case DFA_PIX_32BIT:
348 		var->transp.length = 8;
349 		break;
350 	}
351 	if (pixfmt != DFA_PIX_8BIT) {
352 		var->blue.offset = 0;
353 		var->green.offset = var->blue.length;
354 		var->red.offset = var->green.offset + var->green.length;
355 		if (var->transp.length)
356 			var->transp.offset =
357 				var->red.offset + var->red.length;
358 	}
359 }
360 
361 static int gxt4500_check_var(struct fb_var_screeninfo *var,
362 			     struct fb_info *info)
363 {
364 	struct gxt4500_par par;
365 	int err;
366 
367 	par = *(struct gxt4500_par *)info->par;
368 	err = gxt4500_var_to_par(var, &par);
369 	if (!err) {
370 		var->pixclock = calc_pixclock(&par);
371 		gxt4500_unpack_pixfmt(var, par.pixfmt);
372 	}
373 	return err;
374 }
375 
376 static int gxt4500_set_par(struct fb_info *info)
377 {
378 	struct gxt4500_par *par = info->par;
379 	struct fb_var_screeninfo *var = &info->var;
380 	int err;
381 	u32 ctrlreg, tmp;
382 	unsigned int dfa_ctl, pixfmt, stride;
383 	unsigned int wid_tiles, i;
384 	unsigned int prefetch_pix, htot;
385 	struct gxt4500_par save_par;
386 
387 	save_par = *par;
388 	err = gxt4500_var_to_par(var, par);
389 	if (err) {
390 		*par = save_par;
391 		return err;
392 	}
393 
394 	/* turn off DTG for now */
395 	ctrlreg = readreg(par, DTG_CONTROL);
396 	ctrlreg &= ~(DTG_CTL_ENABLE | DTG_CTL_SCREEN_REFRESH);
397 	writereg(par, DTG_CONTROL, ctrlreg);
398 
399 	/* set PLL registers */
400 	tmp = readreg(par, PLL_C) & ~0x7f;
401 	if (par->pll_n < 38)
402 		tmp |= 0x29;
403 	if (par->pll_n < 69)
404 		tmp |= 0x35;
405 	else if (par->pll_n < 100)
406 		tmp |= 0x76;
407 	else
408 		tmp |= 0x7e;
409 	writereg(par, PLL_C, tmp);
410 	writereg(par, PLL_M, mdivtab[par->pll_m - 1]);
411 	writereg(par, PLL_N, ndivtab[par->pll_n - 2]);
412 	tmp = ((8 - par->pll_pd2) << 3) | (8 - par->pll_pd1);
413 	if (par->pll_pd1 == 8 || par->pll_pd2 == 8) {
414 		/* work around erratum */
415 		writereg(par, PLL_POSTDIV, tmp | 0x9);
416 		udelay(1);
417 	}
418 	writereg(par, PLL_POSTDIV, tmp);
419 	msleep(20);
420 
421 	/* turn off hardware cursor */
422 	writereg(par, CURSOR_MODE, CURSOR_MODE_OFF);
423 
424 	/* reset raster engine */
425 	writereg(par, CTRL_REG0, CR0_RASTER_RESET | (CR0_RASTER_RESET << 16));
426 	udelay(10);
427 	writereg(par, CTRL_REG0, CR0_RASTER_RESET << 16);
428 
429 	/* set display timing generator registers */
430 	htot = var->xres + var->left_margin + var->right_margin +
431 		var->hsync_len;
432 	writereg(par, DTG_HORIZ_EXTENT, htot - 1);
433 	writereg(par, DTG_HORIZ_DISPLAY, var->xres - 1);
434 	writereg(par, DTG_HSYNC_START, var->xres + var->right_margin - 1);
435 	writereg(par, DTG_HSYNC_END,
436 		 var->xres + var->right_margin + var->hsync_len - 1);
437 	writereg(par, DTG_HSYNC_END_COMP,
438 		 var->xres + var->right_margin + var->hsync_len - 1);
439 	writereg(par, DTG_VERT_EXTENT,
440 		 var->yres + var->upper_margin + var->lower_margin +
441 		 var->vsync_len - 1);
442 	writereg(par, DTG_VERT_DISPLAY, var->yres - 1);
443 	writereg(par, DTG_VSYNC_START, var->yres + var->lower_margin - 1);
444 	writereg(par, DTG_VSYNC_END,
445 		 var->yres + var->lower_margin + var->vsync_len - 1);
446 	prefetch_pix = 3300000 / var->pixclock;
447 	if (prefetch_pix >= htot)
448 		prefetch_pix = htot - 1;
449 	writereg(par, DTG_VERT_SHORT, htot - prefetch_pix - 1);
450 	ctrlreg |= DTG_CTL_ENABLE | DTG_CTL_SCREEN_REFRESH;
451 	writereg(par, DTG_CONTROL, ctrlreg);
452 
453 	/* calculate stride in DFA aperture */
454 	if (var->xres_virtual > 2048) {
455 		stride = 4096;
456 		dfa_ctl = DFA_FB_STRIDE_4k;
457 	} else if (var->xres_virtual > 1024) {
458 		stride = 2048;
459 		dfa_ctl = DFA_FB_STRIDE_2k;
460 	} else {
461 		stride = 1024;
462 		dfa_ctl = DFA_FB_STRIDE_1k;
463 	}
464 
465 	/* Set up framebuffer definition */
466 	wid_tiles = (var->xres_virtual + 63) >> 6;
467 
468 	/* XXX add proper FB allocation here someday */
469 	writereg(par, FB_AB_CTRL, FB_CTRL_TYPE | (wid_tiles << 16) | 0);
470 	writereg(par, REFRESH_AB_CTRL, FB_CTRL_TYPE | (wid_tiles << 16) | 0);
471 	writereg(par, FB_CD_CTRL, FB_CTRL_TYPE | (wid_tiles << 16) | 0);
472 	writereg(par, REFRESH_CD_CTRL, FB_CTRL_TYPE | (wid_tiles << 16) | 0);
473 	writereg(par, REFRESH_START, (var->xoffset << 16) | var->yoffset);
474 	writereg(par, REFRESH_SIZE, (var->xres << 16) | var->yres);
475 
476 	/* Set up framebuffer access by CPU */
477 
478 	pixfmt = par->pixfmt;
479 	dfa_ctl |= DFA_FB_ENABLE | pixfmt;
480 	writereg(par, DFA_FB_A, dfa_ctl);
481 
482 	/*
483 	 * Set up window attribute table.
484 	 * We set all WAT entries the same so it doesn't matter what the
485 	 * window ID (WID) plane contains.
486 	 */
487 	for (i = 0; i < 32; ++i) {
488 		writereg(par, WAT_FMT + (i << 4), watfmt[pixfmt]);
489 		writereg(par, WAT_CMAP_OFFSET + (i << 4), 0);
490 		writereg(par, WAT_CTRL + (i << 4), 0);
491 		writereg(par, WAT_GAMMA_CTRL + (i << 4), WAT_GAMMA_DISABLE);
492 	}
493 
494 	/* Set sync polarity etc. */
495 	ctrlreg = readreg(par, SYNC_CTL) &
496 		~(SYNC_CTL_SYNC_ON_RGB | SYNC_CTL_HSYNC_INV |
497 		  SYNC_CTL_VSYNC_INV);
498 	if (var->sync & FB_SYNC_ON_GREEN)
499 		ctrlreg |= SYNC_CTL_SYNC_ON_RGB;
500 	if (!(var->sync & FB_SYNC_HOR_HIGH_ACT))
501 		ctrlreg |= SYNC_CTL_HSYNC_INV;
502 	if (!(var->sync & FB_SYNC_VERT_HIGH_ACT))
503 		ctrlreg |= SYNC_CTL_VSYNC_INV;
504 	writereg(par, SYNC_CTL, ctrlreg);
505 
506 	info->fix.line_length = stride * pixsize[pixfmt];
507 	info->fix.visual = (pixfmt == DFA_PIX_8BIT)? FB_VISUAL_PSEUDOCOLOR:
508 		FB_VISUAL_DIRECTCOLOR;
509 
510 	return 0;
511 }
512 
513 static int gxt4500_setcolreg(unsigned int reg, unsigned int red,
514 			     unsigned int green, unsigned int blue,
515 			     unsigned int transp, struct fb_info *info)
516 {
517 	u32 cmap_entry;
518 	struct gxt4500_par *par = info->par;
519 
520 	if (reg > 1023)
521 		return 1;
522 	cmap_entry = ((transp & 0xff00) << 16) | ((red & 0xff00) << 8) |
523 		(green & 0xff00) | (blue >> 8);
524 	writereg(par, CMAP + reg * 4, cmap_entry);
525 
526 	if (reg < 16 && par->pixfmt != DFA_PIX_8BIT) {
527 		u32 *pal = info->pseudo_palette;
528 		u32 val = reg;
529 		switch (par->pixfmt) {
530 		case DFA_PIX_16BIT_565:
531 			val |= (reg << 11) | (reg << 5);
532 			break;
533 		case DFA_PIX_16BIT_1555:
534 			val |= (reg << 10) | (reg << 5);
535 			break;
536 		case DFA_PIX_32BIT:
537 			val |= (reg << 24);
538 			fallthrough;
539 		case DFA_PIX_24BIT:
540 			val |= (reg << 16) | (reg << 8);
541 			break;
542 		}
543 		pal[reg] = val;
544 	}
545 
546 	return 0;
547 }
548 
549 static int gxt4500_pan_display(struct fb_var_screeninfo *var,
550 			       struct fb_info *info)
551 {
552 	struct gxt4500_par *par = info->par;
553 
554 	if (var->xoffset & 7)
555 		return -EINVAL;
556 	if (var->xoffset + info->var.xres > info->var.xres_virtual ||
557 	    var->yoffset + info->var.yres > info->var.yres_virtual)
558 		return -EINVAL;
559 
560 	writereg(par, REFRESH_START, (var->xoffset << 16) | var->yoffset);
561 	return 0;
562 }
563 
564 static int gxt4500_blank(int blank, struct fb_info *info)
565 {
566 	struct gxt4500_par *par = info->par;
567 	int ctrl, dctl;
568 
569 	ctrl = readreg(par, SYNC_CTL);
570 	ctrl &= ~(SYNC_CTL_SYNC_OFF | SYNC_CTL_HSYNC_OFF | SYNC_CTL_VSYNC_OFF);
571 	dctl = readreg(par, DISP_CTL);
572 	dctl |= DISP_CTL_OFF;
573 	switch (blank) {
574 	case FB_BLANK_UNBLANK:
575 		dctl &= ~DISP_CTL_OFF;
576 		break;
577 	case FB_BLANK_POWERDOWN:
578 		ctrl |= SYNC_CTL_SYNC_OFF;
579 		break;
580 	case FB_BLANK_HSYNC_SUSPEND:
581 		ctrl |= SYNC_CTL_HSYNC_OFF;
582 		break;
583 	case FB_BLANK_VSYNC_SUSPEND:
584 		ctrl |= SYNC_CTL_VSYNC_OFF;
585 		break;
586 	default: ;
587 	}
588 	writereg(par, SYNC_CTL, ctrl);
589 	writereg(par, DISP_CTL, dctl);
590 
591 	return 0;
592 }
593 
594 static const struct fb_fix_screeninfo gxt4500_fix = {
595 	.id = "IBM GXT4500P",
596 	.type = FB_TYPE_PACKED_PIXELS,
597 	.visual = FB_VISUAL_PSEUDOCOLOR,
598 	.xpanstep = 8,
599 	.ypanstep = 1,
600 	.mmio_len = 0x20000,
601 };
602 
603 static const struct fb_ops gxt4500_ops = {
604 	.owner = THIS_MODULE,
605 	.fb_check_var = gxt4500_check_var,
606 	.fb_set_par = gxt4500_set_par,
607 	.fb_setcolreg = gxt4500_setcolreg,
608 	.fb_pan_display = gxt4500_pan_display,
609 	.fb_blank = gxt4500_blank,
610 	.fb_fillrect = cfb_fillrect,
611 	.fb_copyarea = cfb_copyarea,
612 	.fb_imageblit = cfb_imageblit,
613 };
614 
615 /* PCI functions */
616 static int gxt4500_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
617 {
618 	int err;
619 	unsigned long reg_phys, fb_phys;
620 	struct gxt4500_par *par;
621 	struct fb_info *info;
622 	struct fb_var_screeninfo var;
623 	enum gxt_cards cardtype;
624 
625 	err = aperture_remove_conflicting_pci_devices(pdev, "gxt4500fb");
626 	if (err)
627 		return err;
628 
629 	err = pci_enable_device(pdev);
630 	if (err) {
631 		dev_err(&pdev->dev, "gxt4500: cannot enable PCI device: %d\n",
632 			err);
633 		return err;
634 	}
635 
636 	reg_phys = pci_resource_start(pdev, 0);
637 	if (!request_mem_region(reg_phys, pci_resource_len(pdev, 0),
638 				"gxt4500 regs")) {
639 		dev_err(&pdev->dev, "gxt4500: cannot get registers\n");
640 		goto err_nodev;
641 	}
642 
643 	fb_phys = pci_resource_start(pdev, 1);
644 	if (!request_mem_region(fb_phys, pci_resource_len(pdev, 1),
645 				"gxt4500 FB")) {
646 		dev_err(&pdev->dev, "gxt4500: cannot get framebuffer\n");
647 		goto err_free_regs;
648 	}
649 
650 	info = framebuffer_alloc(sizeof(struct gxt4500_par), &pdev->dev);
651 	if (!info)
652 		goto err_free_fb;
653 
654 	par = info->par;
655 	cardtype = ent->driver_data;
656 	par->refclk_ps = cardinfo[cardtype].refclk_ps;
657 	info->fix = gxt4500_fix;
658 	strscpy(info->fix.id, cardinfo[cardtype].cardname,
659 		sizeof(info->fix.id));
660 	info->pseudo_palette = par->pseudo_palette;
661 
662 	info->fix.mmio_start = reg_phys;
663 	par->regs = pci_ioremap_bar(pdev, 0);
664 	if (!par->regs) {
665 		dev_err(&pdev->dev, "gxt4500: cannot map registers\n");
666 		goto err_free_all;
667 	}
668 
669 	info->fix.smem_start = fb_phys;
670 	info->fix.smem_len = pci_resource_len(pdev, 1);
671 	info->screen_base = pci_ioremap_wc_bar(pdev, 1);
672 	if (!info->screen_base) {
673 		dev_err(&pdev->dev, "gxt4500: cannot map framebuffer\n");
674 		goto err_unmap_regs;
675 	}
676 
677 	pci_set_drvdata(pdev, info);
678 
679 	par->wc_cookie = arch_phys_wc_add(info->fix.smem_start,
680 					  info->fix.smem_len);
681 
682 #ifdef __BIG_ENDIAN
683 	/* Set byte-swapping for DFA aperture for all pixel sizes */
684 	pci_write_config_dword(pdev, CFG_ENDIAN0, 0x333300);
685 #else /* __LITTLE_ENDIAN */
686 	/* not sure what this means but fgl23 driver does that */
687 	pci_write_config_dword(pdev, CFG_ENDIAN0, 0x2300);
688 /*	pci_write_config_dword(pdev, CFG_ENDIAN0 + 4, 0x400000);*/
689 	pci_write_config_dword(pdev, CFG_ENDIAN0 + 8, 0x98530000);
690 #endif
691 
692 	info->fbops = &gxt4500_ops;
693 	info->flags = FBINFO_FLAG_DEFAULT | FBINFO_HWACCEL_XPAN |
694 					    FBINFO_HWACCEL_YPAN;
695 
696 	err = fb_alloc_cmap(&info->cmap, 256, 0);
697 	if (err) {
698 		dev_err(&pdev->dev, "gxt4500: cannot allocate cmap\n");
699 		goto err_unmap_all;
700 	}
701 
702 	gxt4500_blank(FB_BLANK_UNBLANK, info);
703 
704 	if (!fb_find_mode(&var, info, mode_option, NULL, 0, &defaultmode, 8)) {
705 		dev_err(&pdev->dev, "gxt4500: cannot find valid video mode\n");
706 		goto err_free_cmap;
707 	}
708 	info->var = var;
709 	if (gxt4500_set_par(info)) {
710 		printk(KERN_ERR "gxt4500: cannot set video mode\n");
711 		goto err_free_cmap;
712 	}
713 
714 	if (register_framebuffer(info) < 0) {
715 		dev_err(&pdev->dev, "gxt4500: cannot register framebuffer\n");
716 		goto err_free_cmap;
717 	}
718 	fb_info(info, "%s frame buffer device\n", info->fix.id);
719 
720 	return 0;
721 
722  err_free_cmap:
723 	fb_dealloc_cmap(&info->cmap);
724  err_unmap_all:
725 	iounmap(info->screen_base);
726  err_unmap_regs:
727 	iounmap(par->regs);
728  err_free_all:
729 	framebuffer_release(info);
730  err_free_fb:
731 	release_mem_region(fb_phys, pci_resource_len(pdev, 1));
732  err_free_regs:
733 	release_mem_region(reg_phys, pci_resource_len(pdev, 0));
734  err_nodev:
735 	return -ENODEV;
736 }
737 
738 static void gxt4500_remove(struct pci_dev *pdev)
739 {
740 	struct fb_info *info = pci_get_drvdata(pdev);
741 	struct gxt4500_par *par;
742 
743 	if (!info)
744 		return;
745 	par = info->par;
746 	unregister_framebuffer(info);
747 	arch_phys_wc_del(par->wc_cookie);
748 	fb_dealloc_cmap(&info->cmap);
749 	iounmap(par->regs);
750 	iounmap(info->screen_base);
751 	release_mem_region(pci_resource_start(pdev, 0),
752 			   pci_resource_len(pdev, 0));
753 	release_mem_region(pci_resource_start(pdev, 1),
754 			   pci_resource_len(pdev, 1));
755 	framebuffer_release(info);
756 }
757 
758 /* supported chipsets */
759 static const struct pci_device_id gxt4500_pci_tbl[] = {
760 	{ PCI_DEVICE(PCI_VENDOR_ID_IBM, PCI_DEVICE_ID_IBM_GXT4500P),
761 	  .driver_data = GXT4500P },
762 	{ PCI_DEVICE(PCI_VENDOR_ID_IBM, PCI_DEVICE_ID_IBM_GXT6500P),
763 	  .driver_data = GXT6500P },
764 	{ PCI_DEVICE(PCI_VENDOR_ID_IBM, PCI_DEVICE_ID_IBM_GXT4000P),
765 	  .driver_data = GXT4000P },
766 	{ PCI_DEVICE(PCI_VENDOR_ID_IBM, PCI_DEVICE_ID_IBM_GXT6000P),
767 	  .driver_data = GXT6000P },
768 	{ 0 }
769 };
770 
771 MODULE_DEVICE_TABLE(pci, gxt4500_pci_tbl);
772 
773 static struct pci_driver gxt4500_driver = {
774 	.name = "gxt4500",
775 	.id_table = gxt4500_pci_tbl,
776 	.probe = gxt4500_probe,
777 	.remove = gxt4500_remove,
778 };
779 
780 static int gxt4500_init(void)
781 {
782 	if (fb_modesetting_disabled("gxt4500"))
783 		return -ENODEV;
784 
785 #ifndef MODULE
786 	if (fb_get_options("gxt4500", &mode_option))
787 		return -ENODEV;
788 #endif
789 
790 	return pci_register_driver(&gxt4500_driver);
791 }
792 module_init(gxt4500_init);
793 
794 static void __exit gxt4500_exit(void)
795 {
796 	pci_unregister_driver(&gxt4500_driver);
797 }
798 module_exit(gxt4500_exit);
799 
800 MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
801 MODULE_DESCRIPTION("FBDev driver for IBM GXT4500P/6500P and GXT4000P/6000P");
802 MODULE_LICENSE("GPL");
803 module_param(mode_option, charp, 0);
804 MODULE_PARM_DESC(mode_option, "Specify resolution as \"<xres>x<yres>[-<bpp>][@<refresh>]\"");
805