xref: /openbmc/linux/drivers/video/fbdev/pmagb-b-fb.c (revision f77d1a49)
1 /*
2  *	linux/drivers/video/pmagb-b-fb.c
3  *
4  *	PMAGB-B TURBOchannel Smart Frame Buffer (SFB) card support,
5  *	derived from:
6  *	"HP300 Topcat framebuffer support (derived from macfb of all things)
7  *	Phil Blundell <philb@gnu.org> 1998", the original code can be
8  *	found in the file hpfb.c in the same directory.
9  *
10  *	DECstation related code Copyright (C) 1999, 2000, 2001 by
11  *	Michael Engel <engel@unix-ag.org>,
12  *	Karsten Merker <merker@linuxtag.org> and
13  *	Harald Koerfgen.
14  *	Copyright (c) 2005, 2006  Maciej W. Rozycki
15  *
16  *	This file is subject to the terms and conditions of the GNU General
17  *	Public License.  See the file COPYING in the main directory of this
18  *	archive for more details.
19  */
20 
21 #include <linux/compiler.h>
22 #include <linux/delay.h>
23 #include <linux/errno.h>
24 #include <linux/fb.h>
25 #include <linux/init.h>
26 #include <linux/kernel.h>
27 #include <linux/module.h>
28 #include <linux/tc.h>
29 #include <linux/types.h>
30 
31 #include <asm/io.h>
32 
33 #include <video/pmagb-b-fb.h>
34 
35 
36 struct pmagbbfb_par {
37 	volatile void __iomem *mmio;
38 	volatile void __iomem *smem;
39 	volatile u32 __iomem *sfb;
40 	volatile u32 __iomem *dac;
41 	unsigned int osc0;
42 	unsigned int osc1;
43 	int slot;
44 };
45 
46 
47 static const struct fb_var_screeninfo pmagbbfb_defined = {
48 	.bits_per_pixel	= 8,
49 	.red.length	= 8,
50 	.green.length	= 8,
51 	.blue.length	= 8,
52 	.activate	= FB_ACTIVATE_NOW,
53 	.height		= -1,
54 	.width		= -1,
55 	.accel_flags	= FB_ACCEL_NONE,
56 	.sync		= FB_SYNC_ON_GREEN,
57 	.vmode		= FB_VMODE_NONINTERLACED,
58 };
59 
60 static const struct fb_fix_screeninfo pmagbbfb_fix = {
61 	.id		= "PMAGB-BA",
62 	.smem_len	= (2048 * 1024),
63 	.type		= FB_TYPE_PACKED_PIXELS,
64 	.visual		= FB_VISUAL_PSEUDOCOLOR,
65 	.mmio_len	= PMAGB_B_FBMEM,
66 };
67 
68 
69 static inline void sfb_write(struct pmagbbfb_par *par, unsigned int reg, u32 v)
70 {
71 	writel(v, par->sfb + reg / 4);
72 }
73 
74 static inline u32 sfb_read(struct pmagbbfb_par *par, unsigned int reg)
75 {
76 	return readl(par->sfb + reg / 4);
77 }
78 
79 static inline void dac_write(struct pmagbbfb_par *par, unsigned int reg, u8 v)
80 {
81 	writeb(v, par->dac + reg / 4);
82 }
83 
84 static inline u8 dac_read(struct pmagbbfb_par *par, unsigned int reg)
85 {
86 	return readb(par->dac + reg / 4);
87 }
88 
89 static inline void gp0_write(struct pmagbbfb_par *par, u32 v)
90 {
91 	writel(v, par->mmio + PMAGB_B_GP0);
92 }
93 
94 
95 /*
96  * Set the palette.
97  */
98 static int pmagbbfb_setcolreg(unsigned int regno, unsigned int red,
99 			      unsigned int green, unsigned int blue,
100 			      unsigned int transp, struct fb_info *info)
101 {
102 	struct pmagbbfb_par *par = info->par;
103 
104 	if (regno >= info->cmap.len)
105 		return 1;
106 
107 	red   >>= 8;	/* The cmap fields are 16 bits    */
108 	green >>= 8;	/* wide, but the hardware colormap */
109 	blue  >>= 8;	/* registers are only 8 bits wide */
110 
111 	mb();
112 	dac_write(par, BT459_ADDR_LO, regno);
113 	dac_write(par, BT459_ADDR_HI, 0x00);
114 	wmb();
115 	dac_write(par, BT459_CMAP, red);
116 	wmb();
117 	dac_write(par, BT459_CMAP, green);
118 	wmb();
119 	dac_write(par, BT459_CMAP, blue);
120 
121 	return 0;
122 }
123 
124 static const struct fb_ops pmagbbfb_ops = {
125 	.owner		= THIS_MODULE,
126 	.fb_setcolreg	= pmagbbfb_setcolreg,
127 	.fb_fillrect	= cfb_fillrect,
128 	.fb_copyarea	= cfb_copyarea,
129 	.fb_imageblit	= cfb_imageblit,
130 };
131 
132 
133 /*
134  * Turn the hardware cursor off.
135  */
136 static void pmagbbfb_erase_cursor(struct fb_info *info)
137 {
138 	struct pmagbbfb_par *par = info->par;
139 
140 	mb();
141 	dac_write(par, BT459_ADDR_LO, 0x00);
142 	dac_write(par, BT459_ADDR_HI, 0x03);
143 	wmb();
144 	dac_write(par, BT459_DATA, 0x00);
145 }
146 
147 /*
148  * Set up screen parameters.
149  */
150 static void pmagbbfb_screen_setup(struct fb_info *info)
151 {
152 	struct pmagbbfb_par *par = info->par;
153 
154 	info->var.xres = ((sfb_read(par, SFB_REG_VID_HOR) >>
155 			   SFB_VID_HOR_PIX_SHIFT) & SFB_VID_HOR_PIX_MASK) * 4;
156 	info->var.xres_virtual = info->var.xres;
157 	info->var.yres = (sfb_read(par, SFB_REG_VID_VER) >>
158 			  SFB_VID_VER_SL_SHIFT) & SFB_VID_VER_SL_MASK;
159 	info->var.yres_virtual = info->var.yres;
160 	info->var.left_margin = ((sfb_read(par, SFB_REG_VID_HOR) >>
161 				  SFB_VID_HOR_BP_SHIFT) &
162 				 SFB_VID_HOR_BP_MASK) * 4;
163 	info->var.right_margin = ((sfb_read(par, SFB_REG_VID_HOR) >>
164 				   SFB_VID_HOR_FP_SHIFT) &
165 				  SFB_VID_HOR_FP_MASK) * 4;
166 	info->var.upper_margin = (sfb_read(par, SFB_REG_VID_VER) >>
167 				  SFB_VID_VER_BP_SHIFT) & SFB_VID_VER_BP_MASK;
168 	info->var.lower_margin = (sfb_read(par, SFB_REG_VID_VER) >>
169 				  SFB_VID_VER_FP_SHIFT) & SFB_VID_VER_FP_MASK;
170 	info->var.hsync_len = ((sfb_read(par, SFB_REG_VID_HOR) >>
171 				SFB_VID_HOR_SYN_SHIFT) &
172 			       SFB_VID_HOR_SYN_MASK) * 4;
173 	info->var.vsync_len = (sfb_read(par, SFB_REG_VID_VER) >>
174 			       SFB_VID_VER_SYN_SHIFT) & SFB_VID_VER_SYN_MASK;
175 
176 	info->fix.line_length = info->var.xres;
177 };
178 
179 /*
180  * Determine oscillator configuration.
181  */
182 static void pmagbbfb_osc_setup(struct fb_info *info)
183 {
184 	static unsigned int pmagbbfb_freqs[] = {
185 		130808, 119843, 104000, 92980, 74370, 72800,
186 		69197, 66000, 65000, 50350, 36000, 32000, 25175
187 	};
188 	struct pmagbbfb_par *par = info->par;
189 	struct tc_bus *tbus = to_tc_dev(info->device)->bus;
190 	u32 count0 = 8, count1 = 8, counttc = 16 * 256 + 8;
191 	u32 freq0, freq1, freqtc = tc_get_speed(tbus) / 250;
192 	int i, j;
193 
194 	gp0_write(par, 0);				/* select Osc0 */
195 	for (j = 0; j < 16; j++) {
196 		mb();
197 		sfb_write(par, SFB_REG_TCCLK_COUNT, 0);
198 		mb();
199 		for (i = 0; i < 100; i++) {	/* nominally max. 20.5us */
200 			if (sfb_read(par, SFB_REG_TCCLK_COUNT) == 0)
201 				break;
202 			udelay(1);
203 		}
204 		count0 += sfb_read(par, SFB_REG_VIDCLK_COUNT);
205 	}
206 
207 	gp0_write(par, 1);				/* select Osc1 */
208 	for (j = 0; j < 16; j++) {
209 		mb();
210 		sfb_write(par, SFB_REG_TCCLK_COUNT, 0);
211 
212 		for (i = 0; i < 100; i++) {	/* nominally max. 20.5us */
213 			if (sfb_read(par, SFB_REG_TCCLK_COUNT) == 0)
214 				break;
215 			udelay(1);
216 		}
217 		count1 += sfb_read(par, SFB_REG_VIDCLK_COUNT);
218 	}
219 
220 	freq0 = (freqtc * count0 + counttc / 2) / counttc;
221 	par->osc0 = freq0;
222 	if (freq0 >= pmagbbfb_freqs[0] - (pmagbbfb_freqs[0] + 32) / 64 &&
223 	    freq0 <= pmagbbfb_freqs[0] + (pmagbbfb_freqs[0] + 32) / 64)
224 		par->osc0 = pmagbbfb_freqs[0];
225 
226 	freq1 = (par->osc0 * count1 + count0 / 2) / count0;
227 	par->osc1 = freq1;
228 	for (i = 0; i < ARRAY_SIZE(pmagbbfb_freqs); i++)
229 		if (freq1 >= pmagbbfb_freqs[i] -
230 			     (pmagbbfb_freqs[i] + 128) / 256 &&
231 		    freq1 <= pmagbbfb_freqs[i] +
232 			     (pmagbbfb_freqs[i] + 128) / 256) {
233 			par->osc1 = pmagbbfb_freqs[i];
234 			break;
235 		}
236 
237 	if (par->osc0 - par->osc1 <= (par->osc0 + par->osc1 + 256) / 512 ||
238 	    par->osc1 - par->osc0 <= (par->osc0 + par->osc1 + 256) / 512)
239 		par->osc1 = 0;
240 
241 	gp0_write(par, par->osc1 != 0);			/* reselect OscX */
242 
243 	info->var.pixclock = par->osc1 ?
244 			     (1000000000 + par->osc1 / 2) / par->osc1 :
245 			     (1000000000 + par->osc0 / 2) / par->osc0;
246 };
247 
248 
249 static int pmagbbfb_probe(struct device *dev)
250 {
251 	struct tc_dev *tdev = to_tc_dev(dev);
252 	resource_size_t start, len;
253 	struct fb_info *info;
254 	struct pmagbbfb_par *par;
255 	char freq0[12], freq1[12];
256 	u32 vid_base;
257 	int err;
258 
259 	info = framebuffer_alloc(sizeof(struct pmagbbfb_par), dev);
260 	if (!info)
261 		return -ENOMEM;
262 
263 	par = info->par;
264 	dev_set_drvdata(dev, info);
265 
266 	if (fb_alloc_cmap(&info->cmap, 256, 0) < 0) {
267 		printk(KERN_ERR "%s: Cannot allocate color map\n",
268 		       dev_name(dev));
269 		err = -ENOMEM;
270 		goto err_alloc;
271 	}
272 
273 	info->fbops = &pmagbbfb_ops;
274 	info->fix = pmagbbfb_fix;
275 	info->var = pmagbbfb_defined;
276 
277 	/* Request the I/O MEM resource.  */
278 	start = tdev->resource.start;
279 	len = tdev->resource.end - start + 1;
280 	if (!request_mem_region(start, len, dev_name(dev))) {
281 		printk(KERN_ERR "%s: Cannot reserve FB region\n",
282 		       dev_name(dev));
283 		err = -EBUSY;
284 		goto err_cmap;
285 	}
286 
287 	/* MMIO mapping setup.  */
288 	info->fix.mmio_start = start;
289 	par->mmio = ioremap(info->fix.mmio_start, info->fix.mmio_len);
290 	if (!par->mmio) {
291 		printk(KERN_ERR "%s: Cannot map MMIO\n", dev_name(dev));
292 		err = -ENOMEM;
293 		goto err_resource;
294 	}
295 	par->sfb = par->mmio + PMAGB_B_SFB;
296 	par->dac = par->mmio + PMAGB_B_BT459;
297 
298 	/* Frame buffer mapping setup.  */
299 	info->fix.smem_start = start + PMAGB_B_FBMEM;
300 	par->smem = ioremap(info->fix.smem_start, info->fix.smem_len);
301 	if (!par->smem) {
302 		printk(KERN_ERR "%s: Cannot map FB\n", dev_name(dev));
303 		err = -ENOMEM;
304 		goto err_mmio_map;
305 	}
306 	vid_base = sfb_read(par, SFB_REG_VID_BASE);
307 	info->screen_base = (void __iomem *)par->smem + vid_base * 0x1000;
308 	info->screen_size = info->fix.smem_len - 2 * vid_base * 0x1000;
309 
310 	pmagbbfb_erase_cursor(info);
311 	pmagbbfb_screen_setup(info);
312 	pmagbbfb_osc_setup(info);
313 
314 	err = register_framebuffer(info);
315 	if (err < 0) {
316 		printk(KERN_ERR "%s: Cannot register framebuffer\n",
317 		       dev_name(dev));
318 		goto err_smem_map;
319 	}
320 
321 	get_device(dev);
322 
323 	snprintf(freq0, sizeof(freq0), "%u.%03uMHz",
324 		 par->osc0 / 1000, par->osc0 % 1000);
325 	snprintf(freq1, sizeof(freq1), "%u.%03uMHz",
326 		 par->osc1 / 1000, par->osc1 % 1000);
327 
328 	fb_info(info, "%s frame buffer device at %s\n",
329 		info->fix.id, dev_name(dev));
330 	fb_info(info, "Osc0: %s, Osc1: %s, Osc%u selected\n",
331 		freq0, par->osc1 ? freq1 : "disabled", par->osc1 != 0);
332 
333 	return 0;
334 
335 
336 err_smem_map:
337 	iounmap(par->smem);
338 
339 err_mmio_map:
340 	iounmap(par->mmio);
341 
342 err_resource:
343 	release_mem_region(start, len);
344 
345 err_cmap:
346 	fb_dealloc_cmap(&info->cmap);
347 
348 err_alloc:
349 	framebuffer_release(info);
350 	return err;
351 }
352 
353 static int pmagbbfb_remove(struct device *dev)
354 {
355 	struct tc_dev *tdev = to_tc_dev(dev);
356 	struct fb_info *info = dev_get_drvdata(dev);
357 	struct pmagbbfb_par *par = info->par;
358 	resource_size_t start, len;
359 
360 	put_device(dev);
361 	unregister_framebuffer(info);
362 	iounmap(par->smem);
363 	iounmap(par->mmio);
364 	start = tdev->resource.start;
365 	len = tdev->resource.end - start + 1;
366 	release_mem_region(start, len);
367 	fb_dealloc_cmap(&info->cmap);
368 	framebuffer_release(info);
369 	return 0;
370 }
371 
372 
373 /*
374  * Initialize the framebuffer.
375  */
376 static const struct tc_device_id pmagbbfb_tc_table[] = {
377 	{ "DEC     ", "PMAGB-BA" },
378 	{ }
379 };
380 MODULE_DEVICE_TABLE(tc, pmagbbfb_tc_table);
381 
382 static struct tc_driver pmagbbfb_driver = {
383 	.id_table	= pmagbbfb_tc_table,
384 	.driver		= {
385 		.name	= "pmagbbfb",
386 		.bus	= &tc_bus_type,
387 		.probe	= pmagbbfb_probe,
388 		.remove	= pmagbbfb_remove,
389 	},
390 };
391 
392 static int __init pmagbbfb_init(void)
393 {
394 #ifndef MODULE
395 	if (fb_get_options("pmagbbfb", NULL))
396 		return -ENXIO;
397 #endif
398 	return tc_register_driver(&pmagbbfb_driver);
399 }
400 
401 static void __exit pmagbbfb_exit(void)
402 {
403 	tc_unregister_driver(&pmagbbfb_driver);
404 }
405 
406 
407 module_init(pmagbbfb_init);
408 module_exit(pmagbbfb_exit);
409 
410 MODULE_LICENSE("GPL");
411