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 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
60static 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
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 const struct fb_ops pmagbbfb_ops = {
125	.owner		= THIS_MODULE,
126	FB_DEFAULT_IOMEM_OPS,
127	.fb_setcolreg	= pmagbbfb_setcolreg,
128};
129
130
131/*
132 * Turn the hardware cursor off.
133 */
134static void pmagbbfb_erase_cursor(struct fb_info *info)
135{
136	struct pmagbbfb_par *par = info->par;
137
138	mb();
139	dac_write(par, BT459_ADDR_LO, 0x00);
140	dac_write(par, BT459_ADDR_HI, 0x03);
141	wmb();
142	dac_write(par, BT459_DATA, 0x00);
143}
144
145/*
146 * Set up screen parameters.
147 */
148static void pmagbbfb_screen_setup(struct fb_info *info)
149{
150	struct pmagbbfb_par *par = info->par;
151
152	info->var.xres = ((sfb_read(par, SFB_REG_VID_HOR) >>
153			   SFB_VID_HOR_PIX_SHIFT) & SFB_VID_HOR_PIX_MASK) * 4;
154	info->var.xres_virtual = info->var.xres;
155	info->var.yres = (sfb_read(par, SFB_REG_VID_VER) >>
156			  SFB_VID_VER_SL_SHIFT) & SFB_VID_VER_SL_MASK;
157	info->var.yres_virtual = info->var.yres;
158	info->var.left_margin = ((sfb_read(par, SFB_REG_VID_HOR) >>
159				  SFB_VID_HOR_BP_SHIFT) &
160				 SFB_VID_HOR_BP_MASK) * 4;
161	info->var.right_margin = ((sfb_read(par, SFB_REG_VID_HOR) >>
162				   SFB_VID_HOR_FP_SHIFT) &
163				  SFB_VID_HOR_FP_MASK) * 4;
164	info->var.upper_margin = (sfb_read(par, SFB_REG_VID_VER) >>
165				  SFB_VID_VER_BP_SHIFT) & SFB_VID_VER_BP_MASK;
166	info->var.lower_margin = (sfb_read(par, SFB_REG_VID_VER) >>
167				  SFB_VID_VER_FP_SHIFT) & SFB_VID_VER_FP_MASK;
168	info->var.hsync_len = ((sfb_read(par, SFB_REG_VID_HOR) >>
169				SFB_VID_HOR_SYN_SHIFT) &
170			       SFB_VID_HOR_SYN_MASK) * 4;
171	info->var.vsync_len = (sfb_read(par, SFB_REG_VID_VER) >>
172			       SFB_VID_VER_SYN_SHIFT) & SFB_VID_VER_SYN_MASK;
173
174	info->fix.line_length = info->var.xres;
175};
176
177/*
178 * Determine oscillator configuration.
179 */
180static void pmagbbfb_osc_setup(struct fb_info *info)
181{
182	static unsigned int pmagbbfb_freqs[] = {
183		130808, 119843, 104000, 92980, 74370, 72800,
184		69197, 66000, 65000, 50350, 36000, 32000, 25175
185	};
186	struct pmagbbfb_par *par = info->par;
187	struct tc_bus *tbus = to_tc_dev(info->device)->bus;
188	u32 count0 = 8, count1 = 8, counttc = 16 * 256 + 8;
189	u32 freq0, freq1, freqtc = tc_get_speed(tbus) / 250;
190	int i, j;
191
192	gp0_write(par, 0);				/* select Osc0 */
193	for (j = 0; j < 16; j++) {
194		mb();
195		sfb_write(par, SFB_REG_TCCLK_COUNT, 0);
196		mb();
197		for (i = 0; i < 100; i++) {	/* nominally max. 20.5us */
198			if (sfb_read(par, SFB_REG_TCCLK_COUNT) == 0)
199				break;
200			udelay(1);
201		}
202		count0 += sfb_read(par, SFB_REG_VIDCLK_COUNT);
203	}
204
205	gp0_write(par, 1);				/* select Osc1 */
206	for (j = 0; j < 16; j++) {
207		mb();
208		sfb_write(par, SFB_REG_TCCLK_COUNT, 0);
209
210		for (i = 0; i < 100; i++) {	/* nominally max. 20.5us */
211			if (sfb_read(par, SFB_REG_TCCLK_COUNT) == 0)
212				break;
213			udelay(1);
214		}
215		count1 += sfb_read(par, SFB_REG_VIDCLK_COUNT);
216	}
217
218	freq0 = (freqtc * count0 + counttc / 2) / counttc;
219	par->osc0 = freq0;
220	if (freq0 >= pmagbbfb_freqs[0] - (pmagbbfb_freqs[0] + 32) / 64 &&
221	    freq0 <= pmagbbfb_freqs[0] + (pmagbbfb_freqs[0] + 32) / 64)
222		par->osc0 = pmagbbfb_freqs[0];
223
224	freq1 = (par->osc0 * count1 + count0 / 2) / count0;
225	par->osc1 = freq1;
226	for (i = 0; i < ARRAY_SIZE(pmagbbfb_freqs); i++)
227		if (freq1 >= pmagbbfb_freqs[i] -
228			     (pmagbbfb_freqs[i] + 128) / 256 &&
229		    freq1 <= pmagbbfb_freqs[i] +
230			     (pmagbbfb_freqs[i] + 128) / 256) {
231			par->osc1 = pmagbbfb_freqs[i];
232			break;
233		}
234
235	if (par->osc0 - par->osc1 <= (par->osc0 + par->osc1 + 256) / 512 ||
236	    par->osc1 - par->osc0 <= (par->osc0 + par->osc1 + 256) / 512)
237		par->osc1 = 0;
238
239	gp0_write(par, par->osc1 != 0);			/* reselect OscX */
240
241	info->var.pixclock = par->osc1 ?
242			     (1000000000 + par->osc1 / 2) / par->osc1 :
243			     (1000000000 + par->osc0 / 2) / par->osc0;
244};
245
246
247static int pmagbbfb_probe(struct device *dev)
248{
249	struct tc_dev *tdev = to_tc_dev(dev);
250	resource_size_t start, len;
251	struct fb_info *info;
252	struct pmagbbfb_par *par;
253	char freq0[12], freq1[12];
254	u32 vid_base;
255	int err;
256
257	info = framebuffer_alloc(sizeof(struct pmagbbfb_par), dev);
258	if (!info)
259		return -ENOMEM;
260
261	par = info->par;
262	dev_set_drvdata(dev, info);
263
264	if (fb_alloc_cmap(&info->cmap, 256, 0) < 0) {
265		printk(KERN_ERR "%s: Cannot allocate color map\n",
266		       dev_name(dev));
267		err = -ENOMEM;
268		goto err_alloc;
269	}
270
271	info->fbops = &pmagbbfb_ops;
272	info->fix = pmagbbfb_fix;
273	info->var = pmagbbfb_defined;
274
275	/* Request the I/O MEM resource.  */
276	start = tdev->resource.start;
277	len = tdev->resource.end - start + 1;
278	if (!request_mem_region(start, len, dev_name(dev))) {
279		printk(KERN_ERR "%s: Cannot reserve FB region\n",
280		       dev_name(dev));
281		err = -EBUSY;
282		goto err_cmap;
283	}
284
285	/* MMIO mapping setup.  */
286	info->fix.mmio_start = start;
287	par->mmio = ioremap(info->fix.mmio_start, info->fix.mmio_len);
288	if (!par->mmio) {
289		printk(KERN_ERR "%s: Cannot map MMIO\n", dev_name(dev));
290		err = -ENOMEM;
291		goto err_resource;
292	}
293	par->sfb = par->mmio + PMAGB_B_SFB;
294	par->dac = par->mmio + PMAGB_B_BT459;
295
296	/* Frame buffer mapping setup.  */
297	info->fix.smem_start = start + PMAGB_B_FBMEM;
298	par->smem = ioremap(info->fix.smem_start, info->fix.smem_len);
299	if (!par->smem) {
300		printk(KERN_ERR "%s: Cannot map FB\n", dev_name(dev));
301		err = -ENOMEM;
302		goto err_mmio_map;
303	}
304	vid_base = sfb_read(par, SFB_REG_VID_BASE);
305	info->screen_base = (void __iomem *)par->smem + vid_base * 0x1000;
306	info->screen_size = info->fix.smem_len - 2 * vid_base * 0x1000;
307
308	pmagbbfb_erase_cursor(info);
309	pmagbbfb_screen_setup(info);
310	pmagbbfb_osc_setup(info);
311
312	err = register_framebuffer(info);
313	if (err < 0) {
314		printk(KERN_ERR "%s: Cannot register framebuffer\n",
315		       dev_name(dev));
316		goto err_smem_map;
317	}
318
319	get_device(dev);
320
321	snprintf(freq0, sizeof(freq0), "%u.%03uMHz",
322		 par->osc0 / 1000, par->osc0 % 1000);
323	snprintf(freq1, sizeof(freq1), "%u.%03uMHz",
324		 par->osc1 / 1000, par->osc1 % 1000);
325
326	fb_info(info, "%s frame buffer device at %s\n",
327		info->fix.id, dev_name(dev));
328	fb_info(info, "Osc0: %s, Osc1: %s, Osc%u selected\n",
329		freq0, par->osc1 ? freq1 : "disabled", par->osc1 != 0);
330
331	return 0;
332
333
334err_smem_map:
335	iounmap(par->smem);
336
337err_mmio_map:
338	iounmap(par->mmio);
339
340err_resource:
341	release_mem_region(start, len);
342
343err_cmap:
344	fb_dealloc_cmap(&info->cmap);
345
346err_alloc:
347	framebuffer_release(info);
348	return err;
349}
350
351static int pmagbbfb_remove(struct device *dev)
352{
353	struct tc_dev *tdev = to_tc_dev(dev);
354	struct fb_info *info = dev_get_drvdata(dev);
355	struct pmagbbfb_par *par = info->par;
356	resource_size_t start, len;
357
358	put_device(dev);
359	unregister_framebuffer(info);
360	iounmap(par->smem);
361	iounmap(par->mmio);
362	start = tdev->resource.start;
363	len = tdev->resource.end - start + 1;
364	release_mem_region(start, len);
365	fb_dealloc_cmap(&info->cmap);
366	framebuffer_release(info);
367	return 0;
368}
369
370
371/*
372 * Initialize the framebuffer.
373 */
374static const struct tc_device_id pmagbbfb_tc_table[] = {
375	{ "DEC     ", "PMAGB-BA" },
376	{ }
377};
378MODULE_DEVICE_TABLE(tc, pmagbbfb_tc_table);
379
380static struct tc_driver pmagbbfb_driver = {
381	.id_table	= pmagbbfb_tc_table,
382	.driver		= {
383		.name	= "pmagbbfb",
384		.bus	= &tc_bus_type,
385		.probe	= pmagbbfb_probe,
386		.remove	= pmagbbfb_remove,
387	},
388};
389
390static int __init pmagbbfb_init(void)
391{
392#ifndef MODULE
393	if (fb_get_options("pmagbbfb", NULL))
394		return -ENXIO;
395#endif
396	return tc_register_driver(&pmagbbfb_driver);
397}
398
399static void __exit pmagbbfb_exit(void)
400{
401	tc_unregister_driver(&pmagbbfb_driver);
402}
403
404
405module_init(pmagbbfb_init);
406module_exit(pmagbbfb_exit);
407
408MODULE_LICENSE("GPL");
409