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#include <asm/system.h>
33
34#include <video/pmagb-b-fb.h>
35
36
37struct pmagbbfb_par {
38	volatile void __iomem *mmio;
39	volatile void __iomem *smem;
40	volatile u32 __iomem *sfb;
41	volatile u32 __iomem *dac;
42	unsigned int osc0;
43	unsigned int osc1;
44	int slot;
45};
46
47
48static struct fb_var_screeninfo pmagbbfb_defined __initdata = {
49	.bits_per_pixel	= 8,
50	.red.length	= 8,
51	.green.length	= 8,
52	.blue.length	= 8,
53	.activate	= FB_ACTIVATE_NOW,
54	.height		= -1,
55	.width		= -1,
56	.accel_flags	= FB_ACCEL_NONE,
57	.sync		= FB_SYNC_ON_GREEN,
58	.vmode		= FB_VMODE_NONINTERLACED,
59};
60
61static struct fb_fix_screeninfo pmagbbfb_fix __initdata = {
62	.id		= "PMAGB-BA",
63	.smem_len	= (2048 * 1024),
64	.type		= FB_TYPE_PACKED_PIXELS,
65	.visual		= FB_VISUAL_PSEUDOCOLOR,
66	.mmio_len	= PMAGB_B_FBMEM,
67};
68
69
70static inline void sfb_write(struct pmagbbfb_par *par, unsigned int reg, u32 v)
71{
72	writel(v, par->sfb + reg / 4);
73}
74
75static inline u32 sfb_read(struct pmagbbfb_par *par, unsigned int reg)
76{
77	return readl(par->sfb + reg / 4);
78}
79
80static inline void dac_write(struct pmagbbfb_par *par, unsigned int reg, u8 v)
81{
82	writeb(v, par->dac + reg / 4);
83}
84
85static inline u8 dac_read(struct pmagbbfb_par *par, unsigned int reg)
86{
87	return readb(par->dac + reg / 4);
88}
89
90static inline void gp0_write(struct pmagbbfb_par *par, u32 v)
91{
92	writel(v, par->mmio + PMAGB_B_GP0);
93}
94
95
96/*
97 * Set the palette.
98 */
99static int pmagbbfb_setcolreg(unsigned int regno, unsigned int red,
100			      unsigned int green, unsigned int blue,
101			      unsigned int transp, struct fb_info *info)
102{
103	struct pmagbbfb_par *par = info->par;
104
105	BUG_ON(regno >= info->cmap.len);
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 __init 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 __init pmagbbfb_osc_setup(struct fb_info *info)
183{
184	static unsigned int pmagbbfb_freqs[] __initdata = {
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 __init 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
258	info = framebuffer_alloc(sizeof(struct pmagbbfb_par), dev);
259	if (!info)
260		return -ENOMEM;
261
262	par = info->par;
263	dev_set_drvdata(dev, info);
264
265	if (fb_alloc_cmap(&info->cmap, 256, 0) < 0)
266		goto err_alloc;
267
268	info->fbops = &pmagbbfb_ops;
269	info->fix = pmagbbfb_fix;
270	info->var = pmagbbfb_defined;
271	info->flags = FBINFO_DEFAULT;
272
273	/* Request the I/O MEM resource.  */
274	start = tdev->resource.start;
275	len = tdev->resource.end - start + 1;
276	if (!request_mem_region(start, len, dev->bus_id))
277		goto err_cmap;
278
279	/* MMIO mapping setup.  */
280	info->fix.mmio_start = start;
281	par->mmio = ioremap_nocache(info->fix.mmio_start, info->fix.mmio_len);
282	if (!par->mmio)
283		goto err_resource;
284	par->sfb = par->mmio + PMAGB_B_SFB;
285	par->dac = par->mmio + PMAGB_B_BT459;
286
287	/* Frame buffer mapping setup.  */
288	info->fix.smem_start = start + PMAGB_B_FBMEM;
289	par->smem = ioremap_nocache(info->fix.smem_start, info->fix.smem_len);
290	if (!par->smem)
291		goto err_mmio_map;
292	vid_base = sfb_read(par, SFB_REG_VID_BASE);
293	info->screen_base = (void __iomem *)par->smem + vid_base * 0x1000;
294	info->screen_size = info->fix.smem_len - 2 * vid_base * 0x1000;
295
296	pmagbbfb_erase_cursor(info);
297	pmagbbfb_screen_setup(info);
298	pmagbbfb_osc_setup(info);
299
300	if (register_framebuffer(info) < 0)
301		goto err_smem_map;
302
303	get_device(dev);
304
305	snprintf(freq0, sizeof(freq0), "%u.%03uMHz",
306		 par->osc0 / 1000, par->osc0 % 1000);
307	snprintf(freq1, sizeof(freq1), "%u.%03uMHz",
308		 par->osc1 / 1000, par->osc1 % 1000);
309
310	pr_info("fb%d: %s frame buffer device at %s\n",
311		info->node, info->fix.id, dev->bus_id);
312	pr_info("fb%d: Osc0: %s, Osc1: %s, Osc%u selected\n",
313		info->node, freq0, par->osc1 ? freq1 : "disabled",
314		par->osc1 != 0);
315
316	return 0;
317
318
319err_smem_map:
320	iounmap(par->smem);
321
322err_mmio_map:
323	iounmap(par->mmio);
324
325err_resource:
326	release_mem_region(start, len);
327
328err_cmap:
329	fb_dealloc_cmap(&info->cmap);
330
331err_alloc:
332	framebuffer_release(info);
333	return -ENXIO;
334}
335
336static int __exit pmagbbfb_remove(struct device *dev)
337{
338	struct tc_dev *tdev = to_tc_dev(dev);
339	struct fb_info *info = dev_get_drvdata(dev);
340	struct pmagbbfb_par *par = info->par;
341	resource_size_t start, len;
342
343	put_device(dev);
344	unregister_framebuffer(info);
345	iounmap(par->smem);
346	iounmap(par->mmio);
347	start = tdev->resource.start;
348	len = tdev->resource.end - start + 1;
349	release_mem_region(start, len);
350	fb_dealloc_cmap(&info->cmap);
351	framebuffer_release(info);
352	return 0;
353}
354
355
356/*
357 * Initialize the framebuffer.
358 */
359static const struct tc_device_id pmagbbfb_tc_table[] = {
360	{ "DEC     ", "PMAGB-BA" },
361	{ }
362};
363MODULE_DEVICE_TABLE(tc, pmagbbfb_tc_table);
364
365static struct tc_driver pmagbbfb_driver = {
366	.id_table	= pmagbbfb_tc_table,
367	.driver		= {
368		.name	= "pmagbbfb",
369		.bus	= &tc_bus_type,
370		.probe	= pmagbbfb_probe,
371		.remove	= __exit_p(pmagbbfb_remove),
372	},
373};
374
375static int __init pmagbbfb_init(void)
376{
377#ifndef MODULE
378	if (fb_get_options("pmagbbfb", NULL))
379		return -ENXIO;
380#endif
381	return tc_register_driver(&pmagbbfb_driver);
382}
383
384static void __exit pmagbbfb_exit(void)
385{
386	tc_unregister_driver(&pmagbbfb_driver);
387}
388
389
390module_init(pmagbbfb_init);
391module_exit(pmagbbfb_exit);
392
393MODULE_LICENSE("GPL");
394