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
36struct 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
47static 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
60static 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
69static inline void sfb_write(struct pmagbbfb_par *par, unsigned int reg, u32 v)
70{
71	writel(v, par->sfb + reg / 4);
72}
73
74static inline u32 sfb_read(struct pmagbbfb_par *par, unsigned int reg)
75{
76	return readl(par->sfb + reg / 4);
77}
78
79static inline void dac_write(struct pmagbbfb_par *par, unsigned int reg, u8 v)
80{
81	writeb(v, par->dac + reg / 4);
82}
83
84static inline u8 dac_read(struct pmagbbfb_par *par, unsigned int reg)
85{
86	return readb(par->dac + reg / 4);
87}
88
89static 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 */
98static 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
124static 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 */
136static void __init 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 */
150static 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 */
182static 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
249static 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		printk(KERN_ERR "%s: Cannot allocate memory\n", dev_name(dev));
262		return -ENOMEM;
263	}
264
265	par = info->par;
266	dev_set_drvdata(dev, info);
267
268	if (fb_alloc_cmap(&info->cmap, 256, 0) < 0) {
269		printk(KERN_ERR "%s: Cannot allocate color map\n",
270		       dev_name(dev));
271		err = -ENOMEM;
272		goto err_alloc;
273	}
274
275	info->fbops = &pmagbbfb_ops;
276	info->fix = pmagbbfb_fix;
277	info->var = pmagbbfb_defined;
278	info->flags = FBINFO_DEFAULT;
279
280	/* Request the I/O MEM resource.  */
281	start = tdev->resource.start;
282	len = tdev->resource.end - start + 1;
283	if (!request_mem_region(start, len, dev_name(dev))) {
284		printk(KERN_ERR "%s: Cannot reserve FB region\n",
285		       dev_name(dev));
286		err = -EBUSY;
287		goto err_cmap;
288	}
289
290	/* MMIO mapping setup.  */
291	info->fix.mmio_start = start;
292	par->mmio = ioremap_nocache(info->fix.mmio_start, info->fix.mmio_len);
293	if (!par->mmio) {
294		printk(KERN_ERR "%s: Cannot map MMIO\n", dev_name(dev));
295		err = -ENOMEM;
296		goto err_resource;
297	}
298	par->sfb = par->mmio + PMAGB_B_SFB;
299	par->dac = par->mmio + PMAGB_B_BT459;
300
301	/* Frame buffer mapping setup.  */
302	info->fix.smem_start = start + PMAGB_B_FBMEM;
303	par->smem = ioremap_nocache(info->fix.smem_start, info->fix.smem_len);
304	if (!par->smem) {
305		printk(KERN_ERR "%s: Cannot map FB\n", dev_name(dev));
306		err = -ENOMEM;
307		goto err_mmio_map;
308	}
309	vid_base = sfb_read(par, SFB_REG_VID_BASE);
310	info->screen_base = (void __iomem *)par->smem + vid_base * 0x1000;
311	info->screen_size = info->fix.smem_len - 2 * vid_base * 0x1000;
312
313	pmagbbfb_erase_cursor(info);
314	pmagbbfb_screen_setup(info);
315	pmagbbfb_osc_setup(info);
316
317	err = register_framebuffer(info);
318	if (err < 0) {
319		printk(KERN_ERR "%s: Cannot register framebuffer\n",
320		       dev_name(dev));
321		goto err_smem_map;
322	}
323
324	get_device(dev);
325
326	snprintf(freq0, sizeof(freq0), "%u.%03uMHz",
327		 par->osc0 / 1000, par->osc0 % 1000);
328	snprintf(freq1, sizeof(freq1), "%u.%03uMHz",
329		 par->osc1 / 1000, par->osc1 % 1000);
330
331	fb_info(info, "%s frame buffer device at %s\n",
332		info->fix.id, dev_name(dev));
333	fb_info(info, "Osc0: %s, Osc1: %s, Osc%u selected\n",
334		freq0, par->osc1 ? freq1 : "disabled", par->osc1 != 0);
335
336	return 0;
337
338
339err_smem_map:
340	iounmap(par->smem);
341
342err_mmio_map:
343	iounmap(par->mmio);
344
345err_resource:
346	release_mem_region(start, len);
347
348err_cmap:
349	fb_dealloc_cmap(&info->cmap);
350
351err_alloc:
352	framebuffer_release(info);
353	return err;
354}
355
356static int __exit pmagbbfb_remove(struct device *dev)
357{
358	struct tc_dev *tdev = to_tc_dev(dev);
359	struct fb_info *info = dev_get_drvdata(dev);
360	struct pmagbbfb_par *par = info->par;
361	resource_size_t start, len;
362
363	put_device(dev);
364	unregister_framebuffer(info);
365	iounmap(par->smem);
366	iounmap(par->mmio);
367	start = tdev->resource.start;
368	len = tdev->resource.end - start + 1;
369	release_mem_region(start, len);
370	fb_dealloc_cmap(&info->cmap);
371	framebuffer_release(info);
372	return 0;
373}
374
375
376/*
377 * Initialize the framebuffer.
378 */
379static const struct tc_device_id pmagbbfb_tc_table[] = {
380	{ "DEC     ", "PMAGB-BA" },
381	{ }
382};
383MODULE_DEVICE_TABLE(tc, pmagbbfb_tc_table);
384
385static struct tc_driver pmagbbfb_driver = {
386	.id_table	= pmagbbfb_tc_table,
387	.driver		= {
388		.name	= "pmagbbfb",
389		.bus	= &tc_bus_type,
390		.probe	= pmagbbfb_probe,
391		.remove	= __exit_p(pmagbbfb_remove),
392	},
393};
394
395static int __init pmagbbfb_init(void)
396{
397#ifndef MODULE
398	if (fb_get_options("pmagbbfb", NULL))
399		return -ENXIO;
400#endif
401	return tc_register_driver(&pmagbbfb_driver);
402}
403
404static void __exit pmagbbfb_exit(void)
405{
406	tc_unregister_driver(&pmagbbfb_driver);
407}
408
409
410module_init(pmagbbfb_init);
411module_exit(pmagbbfb_exit);
412
413MODULE_LICENSE("GPL");
414