xref: /openbmc/u-boot/board/freescale/p1022ds/diu.c (revision 00a2749d)
1 /*
2  * Copyright 2010-2011 Freescale Semiconductor, Inc.
3  * Authors: Timur Tabi <timur@freescale.com>
4  *
5  * FSL DIU Framebuffer driver
6  *
7  * This program is free software; you can redistribute it and/or modify it
8  * under the terms of the GNU General Public License as published by the Free
9  * Software Foundation; either version 2 of the License, or (at your option)
10  * any later version.
11  */
12 
13 #include <common.h>
14 #include <command.h>
15 #include <linux/ctype.h>
16 #include <asm/io.h>
17 #include <stdio_dev.h>
18 #include <video_fb.h>
19 #include "../common/ngpixis.h"
20 #include <fsl_diu_fb.h>
21 
22 /* The CTL register is called 'csr' in the ngpixis_t structure */
23 #define PX_CTL_ALTACC		0x80
24 
25 #define PX_BRDCFG0_ELBC_SPI_MASK	0xc0
26 #define PX_BRDCFG0_ELBC_SPI_ELBC	0x00
27 #define PX_BRDCFG0_ELBC_SPI_NULL	0xc0
28 #define PX_BRDCFG0_ELBC_DIU		0x02
29 
30 #define PX_BRDCFG1_DVIEN	0x80
31 #define PX_BRDCFG1_DFPEN	0x40
32 #define PX_BRDCFG1_BACKLIGHT	0x20
33 
34 #define PMUXCR_ELBCDIU_MASK	0xc0000000
35 #define PMUXCR_ELBCDIU_NOR16	0x80000000
36 #define PMUXCR_ELBCDIU_DIU	0x40000000
37 
38 /*
39  * DIU Area Descriptor
40  *
41  * Note that we need to byte-swap the value before it's written to the AD
42  * register.  So even though the registers don't look like they're in the same
43  * bit positions as they are on the MPC8610, the same value is written to the
44  * AD register on the MPC8610 and on the P1022.
45  */
46 #define AD_BYTE_F		0x10000000
47 #define AD_ALPHA_C_SHIFT	25
48 #define AD_BLUE_C_SHIFT		23
49 #define AD_GREEN_C_SHIFT	21
50 #define AD_RED_C_SHIFT		19
51 #define AD_PIXEL_S_SHIFT	16
52 #define AD_COMP_3_SHIFT		12
53 #define AD_COMP_2_SHIFT		8
54 #define AD_COMP_1_SHIFT		4
55 #define AD_COMP_0_SHIFT		0
56 
57 /*
58  * Variables used by the DIU/LBC switching code.  It's safe to makes these
59  * global, because the DIU requires DDR, so we'll only run this code after
60  * relocation.
61  */
62 static u8 px_brdcfg0;
63 static u32 pmuxcr;
64 static void *lbc_lcs0_ba;
65 static void *lbc_lcs1_ba;
66 static u32 old_br0, old_or0, old_br1, old_or1;
67 static u32 new_br0, new_or0, new_br1, new_or1;
68 
69 void diu_set_pixel_clock(unsigned int pixclock)
70 {
71 	ccsr_gur_t *gur = (void *)(CONFIG_SYS_MPC85xx_GUTS_ADDR);
72 	unsigned long speed_ccb, temp;
73 	u32 pixval;
74 
75 	speed_ccb = get_bus_freq(0);
76 	temp = 1000000000 / pixclock;
77 	temp *= 1000;
78 	pixval = speed_ccb / temp;
79 	debug("DIU pixval = %u\n", pixval);
80 
81 	/* Modify PXCLK in GUTS CLKDVDR */
82 	temp = in_be32(&gur->clkdvdr) & 0x2000FFFF;
83 	out_be32(&gur->clkdvdr, temp);			/* turn off clock */
84 	out_be32(&gur->clkdvdr, temp | 0x80000000 | ((pixval & 0x1F) << 16));
85 }
86 
87 int platform_diu_init(unsigned int xres, unsigned int yres, const char *port)
88 {
89 	ccsr_gur_t *gur = (void *)(CONFIG_SYS_MPC85xx_GUTS_ADDR);
90 	const char *name;
91 	u32 pixel_format;
92 	u8 temp;
93 	phys_addr_t phys0, phys1; /* BR0/BR1 physical addresses */
94 
95 	/*
96 	 * Indirect mode requires both BR0 and BR1 to be set to "GPCM",
97 	 * otherwise writes to these addresses won't actually appear on the
98 	 * local bus, and so the PIXIS won't see them.
99 	 *
100 	 * In FCM mode, writes go to the NAND controller, which does not pass
101 	 * them to the localbus directly.  So we force BR0 and BR1 into GPCM
102 	 * mode, since we don't care about what's behind the localbus any
103 	 * more.  However, we save those registers first, so that we can
104 	 * restore them when necessary.
105 	 */
106 	new_br0 = old_br0 = get_lbc_br(0);
107 	new_br1 = old_br1 = get_lbc_br(1);
108 	new_or0 = old_or0 = get_lbc_or(0);
109 	new_or1 = old_or1 = get_lbc_or(1);
110 
111 	/*
112 	 * Use the existing BRx/ORx values if it's already GPCM. Otherwise,
113 	 * force the values to simple 32KB GPCM windows with the most
114 	 * conservative timing.
115 	 */
116 	if ((old_br0 & BR_MSEL) != BR_MS_GPCM) {
117 		new_br0 = (get_lbc_br(0) & BR_BA) | BR_V;
118 		new_or0 = OR_AM_32KB | 0xFF7;
119 		set_lbc_br(0, new_br0);
120 		set_lbc_or(0, new_or0);
121 	}
122 	if ((old_br1 & BR_MSEL) != BR_MS_GPCM) {
123 		new_br1 = (get_lbc_br(1) & BR_BA) | BR_V;
124 		new_or1 = OR_AM_32KB | 0xFF7;
125 		set_lbc_br(1, new_br1);
126 		set_lbc_or(1, new_or1);
127 	}
128 
129 	/*
130 	 * Determine the physical addresses for Chip Selects 0 and 1.  The
131 	 * BR0/BR1 registers contain the truncated physical addresses for the
132 	 * chip selects, mapped via the localbus LAW.  Since the BRx registers
133 	 * only contain the lower 32 bits of the address, we have to determine
134 	 * the upper 4 bits some other way.  The proper way is to scan the LAW
135 	 * table looking for a matching localbus address. Instead, we cheat.
136 	 * We know that the upper bits are 0 for 32-bit addressing, or 0xF for
137 	 * 36-bit addressing.
138 	 */
139 #ifdef CONFIG_PHYS_64BIT
140 	phys0 = 0xf00000000ULL | (old_br0 & old_or0 & BR_BA);
141 	phys1 = 0xf00000000ULL | (old_br1 & old_or1 & BR_BA);
142 #else
143 	phys0 = old_br0 & old_or0 & BR_BA;
144 	phys1 = old_br1 & old_or1 & BR_BA;
145 #endif
146 
147 	 /* Save the LBC LCS0 and LCS1 addresses for the DIU mux functions */
148 	lbc_lcs0_ba = map_physmem(phys0, 1, 0);
149 	lbc_lcs1_ba = map_physmem(phys1, 1, 0);
150 
151 	pixel_format = cpu_to_le32(AD_BYTE_F | (3 << AD_ALPHA_C_SHIFT) |
152 		(0 << AD_BLUE_C_SHIFT) | (1 << AD_GREEN_C_SHIFT) |
153 		(2 << AD_RED_C_SHIFT) | (8 << AD_COMP_3_SHIFT) |
154 		(8 << AD_COMP_2_SHIFT) | (8 << AD_COMP_1_SHIFT) |
155 		(8 << AD_COMP_0_SHIFT) | (3 << AD_PIXEL_S_SHIFT));
156 
157 	temp = in_8(&pixis->brdcfg1);
158 
159 	if (strncmp(port, "lvds", 4) == 0) {
160 		/* Single link LVDS */
161 		temp &= ~PX_BRDCFG1_DVIEN;
162 		/*
163 		 * LVDS also needs backlight enabled, otherwise the display
164 		 * will be blank.
165 		 */
166 		temp |= (PX_BRDCFG1_DFPEN | PX_BRDCFG1_BACKLIGHT);
167 		name = "Single-Link LVDS";
168 	} else {	/* DVI */
169 		/* Enable the DVI port, disable the DFP and the backlight */
170 		temp &= ~(PX_BRDCFG1_DFPEN | PX_BRDCFG1_BACKLIGHT);
171 		temp |= PX_BRDCFG1_DVIEN;
172 		name = "DVI";
173 	}
174 
175 	printf("DIU:   Switching to %s monitor @ %ux%u\n", name, xres, yres);
176 	out_8(&pixis->brdcfg1, temp);
177 
178 	/*
179 	 * Enable PIXIS indirect access mode.  This is a hack that allows us to
180 	 * access PIXIS registers even when the LBC pins have been muxed to the
181 	 * DIU.
182 	 */
183 	setbits_8(&pixis->csr, PX_CTL_ALTACC);
184 
185 	/*
186 	 * Route the LAD pins to the DIU.  This will disable access to the eLBC,
187 	 * which means we won't be able to read/write any NOR flash addresses!
188 	 */
189 	out_8(lbc_lcs0_ba, offsetof(ngpixis_t, brdcfg0));
190 	px_brdcfg0 = in_8(lbc_lcs1_ba);
191 	out_8(lbc_lcs1_ba, px_brdcfg0 | PX_BRDCFG0_ELBC_DIU);
192 	in_8(lbc_lcs1_ba);
193 
194 	/* Set PMUXCR to switch the muxed pins from the LBC to the DIU */
195 	clrsetbits_be32(&gur->pmuxcr, PMUXCR_ELBCDIU_MASK, PMUXCR_ELBCDIU_DIU);
196 	pmuxcr = in_be32(&gur->pmuxcr);
197 
198 	return fsl_diu_init(xres, yres, pixel_format, 0);
199 }
200 
201 /*
202  * set_mux_to_lbc - disable the DIU so that we can read/write to elbc
203  *
204  * On the Freescale P1022, the DIU video signal and the LBC address/data lines
205  * share the same pins, which means that when the DIU is active (e.g. the
206  * console is on the DVI display), NOR flash cannot be accessed.  So we use the
207  * weak accessor feature of the CFI flash code to temporarily switch the pin
208  * mux from DIU to LBC whenever we want to read or write flash.  This has a
209  * significant performance penalty, but it's the only way to make it work.
210  *
211  * There are two muxes: one on the chip, and one on the board. The chip mux
212  * controls whether the pins are used for the DIU or the LBC, and it is
213  * set via PMUXCR.  The board mux controls whether those signals go to
214  * the video connector or the NOR flash chips, and it is set via the ngPIXIS.
215  */
216 static int set_mux_to_lbc(void)
217 {
218 	ccsr_gur_t *gur = (void *)CONFIG_SYS_MPC85xx_GUTS_ADDR;
219 
220 	/* Switch the muxes only if they're currently set to DIU mode */
221 	if ((in_be32(&gur->pmuxcr) & PMUXCR_ELBCDIU_MASK) !=
222 	    PMUXCR_ELBCDIU_NOR16) {
223 		/*
224 		 * In DIU mode, the PIXIS can only be accessed indirectly
225 		 * since we can't read/write the LBC directly.
226 		 */
227 		/* Set the board mux to LBC.  This will disable the display. */
228 		out_8(lbc_lcs0_ba, offsetof(ngpixis_t, brdcfg0));
229 		out_8(lbc_lcs1_ba, px_brdcfg0);
230 		in_8(lbc_lcs1_ba);
231 
232 		/* Disable indirect PIXIS mode */
233 		out_8(lbc_lcs0_ba, offsetof(ngpixis_t, csr));
234 		clrbits_8(lbc_lcs1_ba, PX_CTL_ALTACC);
235 
236 		/* Set the chip mux to LBC mode, so that writes go to flash. */
237 		out_be32(&gur->pmuxcr, (pmuxcr & ~PMUXCR_ELBCDIU_MASK) |
238 			 PMUXCR_ELBCDIU_NOR16);
239 		in_be32(&gur->pmuxcr);
240 
241 		/* Restore the BR0 and BR1 settings */
242 		set_lbc_br(0, old_br0);
243 		set_lbc_or(0, old_or0);
244 		set_lbc_br(1, old_br1);
245 		set_lbc_or(1, old_or1);
246 
247 		return 1;
248 	}
249 
250 	return 0;
251 }
252 
253 /*
254  * set_mux_to_diu - re-enable the DIU muxing
255  *
256  * This function restores the chip and board muxing to point to the DIU.
257  */
258 static void set_mux_to_diu(void)
259 {
260 	ccsr_gur_t *gur = (void *)CONFIG_SYS_MPC85xx_GUTS_ADDR;
261 
262 	/* Set BR0 and BR1 to GPCM mode */
263 	set_lbc_br(0, new_br0);
264 	set_lbc_or(0, new_or0);
265 	set_lbc_br(1, new_br1);
266 	set_lbc_or(1, new_or1);
267 
268 	/* Enable indirect PIXIS mode */
269 	setbits_8(&pixis->csr, PX_CTL_ALTACC);
270 
271 	/* Set the board mux to DIU.  This will enable the display. */
272 	out_8(lbc_lcs0_ba, offsetof(ngpixis_t, brdcfg0));
273 	out_8(lbc_lcs1_ba, px_brdcfg0 | PX_BRDCFG0_ELBC_DIU);
274 	in_8(lbc_lcs1_ba);
275 
276 	/* Set the chip mux to DIU mode. */
277 	out_be32(&gur->pmuxcr, pmuxcr);
278 	in_be32(&gur->pmuxcr);
279 }
280 
281 /*
282  * pixis_read - board-specific function to read from the PIXIS
283  *
284  * This function overrides the generic pixis_read() function, so that it can
285  * use PIXIS indirect mode if necessary.
286  */
287 u8 pixis_read(unsigned int reg)
288 {
289 	ccsr_gur_t *gur = (void *)CONFIG_SYS_MPC85xx_GUTS_ADDR;
290 
291 	/* Use indirect mode if the mux is currently set to DIU mode */
292 	if ((in_be32(&gur->pmuxcr) & PMUXCR_ELBCDIU_MASK) !=
293 	    PMUXCR_ELBCDIU_NOR16) {
294 		out_8(lbc_lcs0_ba, reg);
295 		return in_8(lbc_lcs1_ba);
296 	} else {
297 		void *p = (void *)PIXIS_BASE;
298 
299 		return in_8(p + reg);
300 	}
301 }
302 
303 /*
304  * pixis_write - board-specific function to write to the PIXIS
305  *
306  * This function overrides the generic pixis_write() function, so that it can
307  * use PIXIS indirect mode if necessary.
308  */
309 void pixis_write(unsigned int reg, u8 value)
310 {
311 	ccsr_gur_t *gur = (void *)CONFIG_SYS_MPC85xx_GUTS_ADDR;
312 
313 	/* Use indirect mode if the mux is currently set to DIU mode */
314 	if ((in_be32(&gur->pmuxcr) & PMUXCR_ELBCDIU_MASK) !=
315 	    PMUXCR_ELBCDIU_NOR16) {
316 		out_8(lbc_lcs0_ba, reg);
317 		out_8(lbc_lcs1_ba, value);
318 		/* Do a read-back to ensure the write completed */
319 		in_8(lbc_lcs1_ba);
320 	} else {
321 		void *p = (void *)PIXIS_BASE;
322 
323 		out_8(p + reg, value);
324 	}
325 }
326 
327 void pixis_bank_reset(void)
328 {
329 	/*
330 	 * For some reason, a PIXIS bank reset does not work if the PIXIS is
331 	 * in indirect mode, so switch to direct mode first.
332 	 */
333 	set_mux_to_lbc();
334 
335 	out_8(&pixis->vctl, 0);
336 	out_8(&pixis->vctl, 1);
337 
338 	while (1);
339 }
340 
341 #ifdef CONFIG_CFI_FLASH_USE_WEAK_ACCESSORS
342 
343 void flash_write8(u8 value, void *addr)
344 {
345 	int sw = set_mux_to_lbc();
346 
347 	__raw_writeb(value, addr);
348 	if (sw) {
349 		/*
350 		 * To ensure the post-write is completed to eLBC, software must
351 		 * perform a dummy read from one valid address from eLBC space
352 		 * before changing the eLBC_DIU from NOR mode to DIU mode.
353 		 * set_mux_to_diu() includes a sync that will ensure the
354 		 * __raw_readb() completes before it switches the mux.
355 		 */
356 		__raw_readb(addr);
357 		set_mux_to_diu();
358 	}
359 }
360 
361 void flash_write16(u16 value, void *addr)
362 {
363 	int sw = set_mux_to_lbc();
364 
365 	__raw_writew(value, addr);
366 	if (sw) {
367 		/*
368 		 * To ensure the post-write is completed to eLBC, software must
369 		 * perform a dummy read from one valid address from eLBC space
370 		 * before changing the eLBC_DIU from NOR mode to DIU mode.
371 		 * set_mux_to_diu() includes a sync that will ensure the
372 		 * __raw_readb() completes before it switches the mux.
373 		 */
374 		__raw_readb(addr);
375 		set_mux_to_diu();
376 	}
377 }
378 
379 void flash_write32(u32 value, void *addr)
380 {
381 	int sw = set_mux_to_lbc();
382 
383 	__raw_writel(value, addr);
384 	if (sw) {
385 		/*
386 		 * To ensure the post-write is completed to eLBC, software must
387 		 * perform a dummy read from one valid address from eLBC space
388 		 * before changing the eLBC_DIU from NOR mode to DIU mode.
389 		 * set_mux_to_diu() includes a sync that will ensure the
390 		 * __raw_readb() completes before it switches the mux.
391 		 */
392 		__raw_readb(addr);
393 		set_mux_to_diu();
394 	}
395 }
396 
397 void flash_write64(u64 value, void *addr)
398 {
399 	int sw = set_mux_to_lbc();
400 	uint32_t *p = addr;
401 
402 	/*
403 	 * There is no __raw_writeq(), so do the write manually.  We don't trust
404 	 * the compiler, so we use inline assembly.
405 	 */
406 	__asm__ __volatile__(
407 		"stw%U0%X0 %2,%0;\n"
408 		"stw%U1%X1 %3,%1;\n"
409 		: "=m" (*p), "=m" (*(p + 1))
410 		: "r" ((uint32_t) (value >> 32)), "r" ((uint32_t) (value)));
411 
412 	if (sw) {
413 		/*
414 		 * To ensure the post-write is completed to eLBC, software must
415 		 * perform a dummy read from one valid address from eLBC space
416 		 * before changing the eLBC_DIU from NOR mode to DIU mode.  We
417 		 * read addr+4 because we just wrote to addr+4, so that's how we
418 		 * maintain execution order.  set_mux_to_diu() includes a sync
419 		 * that will ensure the __raw_readb() completes before it
420 		 * switches the mux.
421 		 */
422 		__raw_readb(addr + 4);
423 		set_mux_to_diu();
424 	}
425 }
426 
427 u8 flash_read8(void *addr)
428 {
429 	u8 ret;
430 
431 	int sw = set_mux_to_lbc();
432 
433 	ret = __raw_readb(addr);
434 	if (sw)
435 		set_mux_to_diu();
436 
437 	return ret;
438 }
439 
440 u16 flash_read16(void *addr)
441 {
442 	u16 ret;
443 
444 	int sw = set_mux_to_lbc();
445 
446 	ret = __raw_readw(addr);
447 	if (sw)
448 		set_mux_to_diu();
449 
450 	return ret;
451 }
452 
453 u32 flash_read32(void *addr)
454 {
455 	u32 ret;
456 
457 	int sw = set_mux_to_lbc();
458 
459 	ret = __raw_readl(addr);
460 	if (sw)
461 		set_mux_to_diu();
462 
463 	return ret;
464 }
465 
466 u64 flash_read64(void *addr)
467 {
468 	u64 ret;
469 
470 	int sw = set_mux_to_lbc();
471 
472 	/* There is no __raw_readq(), so do the read manually */
473 	ret = *(volatile u64 *)addr;
474 	if (sw)
475 		set_mux_to_diu();
476 
477 	return ret;
478 }
479 
480 #endif
481