xref: /openbmc/u-boot/board/freescale/p1022ds/diu.c (revision ae03661f)
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 
67 void diu_set_pixel_clock(unsigned int pixclock)
68 {
69 	ccsr_gur_t *gur = (void *)(CONFIG_SYS_MPC85xx_GUTS_ADDR);
70 	unsigned long speed_ccb, temp;
71 	u32 pixval;
72 
73 	speed_ccb = get_bus_freq(0);
74 	temp = 1000000000 / pixclock;
75 	temp *= 1000;
76 	pixval = speed_ccb / temp;
77 	debug("DIU pixval = %u\n", pixval);
78 
79 	/* Modify PXCLK in GUTS CLKDVDR */
80 	temp = in_be32(&gur->clkdvdr) & 0x2000FFFF;
81 	out_be32(&gur->clkdvdr, temp);			/* turn off clock */
82 	out_be32(&gur->clkdvdr, temp | 0x80000000 | ((pixval & 0x1F) << 16));
83 }
84 
85 int platform_diu_init(unsigned int xres, unsigned int yres, const char *port)
86 {
87 	ccsr_gur_t *gur = (void *)(CONFIG_SYS_MPC85xx_GUTS_ADDR);
88 	const char *name;
89 	u32 pixel_format;
90 	u8 temp;
91 
92 	/* Save the LBC LCS0 and LCS1 addresses for the DIU mux functions */
93 	lbc_lcs0_ba = (void *)(get_lbc_br(0) & get_lbc_or(0) & 0xFFFF8000);
94 	lbc_lcs1_ba = (void *)(get_lbc_br(1) & get_lbc_or(1) & 0xFFFF8000);
95 
96 	pixel_format = cpu_to_le32(AD_BYTE_F | (3 << AD_ALPHA_C_SHIFT) |
97 		(0 << AD_BLUE_C_SHIFT) | (1 << AD_GREEN_C_SHIFT) |
98 		(2 << AD_RED_C_SHIFT) | (8 << AD_COMP_3_SHIFT) |
99 		(8 << AD_COMP_2_SHIFT) | (8 << AD_COMP_1_SHIFT) |
100 		(8 << AD_COMP_0_SHIFT) | (3 << AD_PIXEL_S_SHIFT));
101 
102 	temp = in_8(&pixis->brdcfg1);
103 
104 	if (strncmp(port, "lvds", 4) == 0) {
105 		/* Single link LVDS */
106 		temp &= ~PX_BRDCFG1_DVIEN;
107 		/*
108 		 * LVDS also needs backlight enabled, otherwise the display
109 		 * will be blank.
110 		 */
111 		temp |= (PX_BRDCFG1_DFPEN | PX_BRDCFG1_BACKLIGHT);
112 		name = "Single-Link LVDS";
113 	} else {	/* DVI */
114 		/* Enable the DVI port, disable the DFP and the backlight */
115 		temp &= ~(PX_BRDCFG1_DFPEN | PX_BRDCFG1_BACKLIGHT);
116 		temp |= PX_BRDCFG1_DVIEN;
117 		name = "DVI";
118 	}
119 
120 	printf("DIU:   Switching to %s monitor @ %ux%u\n", name, xres, yres);
121 	out_8(&pixis->brdcfg1, temp);
122 
123 	/*
124 	 * Enable PIXIS indirect access mode.  This is a hack that allows us to
125 	 * access PIXIS registers even when the LBC pins have been muxed to the
126 	 * DIU.
127 	 */
128 	setbits_8(&pixis->csr, PX_CTL_ALTACC);
129 
130 	/*
131 	 * Route the LAD pins to the DIU.  This will disable access to the eLBC,
132 	 * which means we won't be able to read/write any NOR flash addresses!
133 	 */
134 	out_8(lbc_lcs0_ba, offsetof(ngpixis_t, brdcfg0));
135 	px_brdcfg0 = in_8(lbc_lcs1_ba);
136 	out_8(lbc_lcs1_ba, px_brdcfg0 | PX_BRDCFG0_ELBC_DIU);
137 
138 	/* Set PMUXCR to switch the muxed pins from the LBC to the DIU */
139 	clrsetbits_be32(&gur->pmuxcr, PMUXCR_ELBCDIU_MASK, PMUXCR_ELBCDIU_DIU);
140 	pmuxcr = in_be32(&gur->pmuxcr);
141 
142 	return fsl_diu_init(xres, yres, pixel_format, 0);
143 }
144 
145 /*
146  * set_mux_to_lbc - disable the DIU so that we can read/write to elbc
147  *
148  * On the Freescale P1022, the DIU video signal and the LBC address/data lines
149  * share the same pins, which means that when the DIU is active (e.g. the
150  * console is on the DVI display), NOR flash cannot be accessed.  So we use the
151  * weak accessor feature of the CFI flash code to temporarily switch the pin
152  * mux from DIU to LBC whenever we want to read or write flash.  This has a
153  * significant performance penalty, but it's the only way to make it work.
154  *
155  * There are two muxes: one on the chip, and one on the board. The chip mux
156  * controls whether the pins are used for the DIU or the LBC, and it is
157  * set via PMUXCR.  The board mux controls whether those signals go to
158  * the video connector or the NOR flash chips, and it is set via the ngPIXIS.
159  */
160 static int set_mux_to_lbc(void)
161 {
162 	ccsr_gur_t *gur = (void *)CONFIG_SYS_MPC85xx_GUTS_ADDR;
163 
164 	/* Switch the muxes only if they're currently set to DIU mode */
165 	if ((in_be32(&gur->pmuxcr) & PMUXCR_ELBCDIU_MASK) !=
166 	    PMUXCR_ELBCDIU_NOR16) {
167 		/*
168 		 * In DIU mode, the PIXIS can only be accessed indirectly
169 		 * since we can't read/write the LBC directly.
170 		 */
171 
172 		/* Set the board mux to LBC.  This will disable the display. */
173 		out_8(lbc_lcs0_ba, offsetof(ngpixis_t, brdcfg0));
174 		px_brdcfg0 = in_8(lbc_lcs1_ba);
175 		out_8(lbc_lcs1_ba, (px_brdcfg0 & ~(PX_BRDCFG0_ELBC_SPI_MASK
176 			| PX_BRDCFG0_ELBC_DIU)) | PX_BRDCFG0_ELBC_SPI_ELBC);
177 
178 		/* Disable indirect PIXIS mode */
179 		out_8(lbc_lcs0_ba, offsetof(ngpixis_t, csr));
180 		clrbits_8(lbc_lcs1_ba, PX_CTL_ALTACC);
181 
182 		/* Set the chip mux to LBC mode, so that writes go to flash. */
183 		out_be32(&gur->pmuxcr, (pmuxcr & ~PMUXCR_ELBCDIU_MASK) |
184 			 PMUXCR_ELBCDIU_NOR16);
185 		in_be32(&gur->pmuxcr);
186 
187 		return 1;
188 	}
189 
190 	return 0;
191 }
192 
193 /*
194  * set_mux_to_diu - re-enable the DIU muxing
195  *
196  * This function restores the chip and board muxing to point to the DIU.
197  */
198 static void set_mux_to_diu(void)
199 {
200 	ccsr_gur_t *gur = (void *)CONFIG_SYS_MPC85xx_GUTS_ADDR;
201 
202 	/* Enable indirect PIXIS mode */
203 	setbits_8(&pixis->csr, PX_CTL_ALTACC);
204 
205 	/* Set the board mux to DIU.  This will enable the display. */
206 	out_8(lbc_lcs0_ba, offsetof(ngpixis_t, brdcfg0));
207 	out_8(lbc_lcs1_ba, px_brdcfg0);
208 	in_8(lbc_lcs1_ba);
209 
210 	/* Set the chip mux to DIU mode. */
211 	out_be32(&gur->pmuxcr, pmuxcr);
212 	in_be32(&gur->pmuxcr);
213 }
214 
215 /*
216  * pixis_read - board-specific function to read from the PIXIS
217  *
218  * This function overrides the generic pixis_read() function, so that it can
219  * use PIXIS indirect mode if necessary.
220  */
221 u8 pixis_read(unsigned int reg)
222 {
223 	ccsr_gur_t *gur = (void *)CONFIG_SYS_MPC85xx_GUTS_ADDR;
224 
225 	/* Use indirect mode if the mux is currently set to DIU mode */
226 	if ((in_be32(&gur->pmuxcr) & PMUXCR_ELBCDIU_MASK) !=
227 	    PMUXCR_ELBCDIU_NOR16) {
228 		out_8(lbc_lcs0_ba, reg);
229 		return in_8(lbc_lcs1_ba);
230 	} else {
231 		void *p = (void *)PIXIS_BASE;
232 
233 		return in_8(p + reg);
234 	}
235 }
236 
237 /*
238  * pixis_write - board-specific function to write to the PIXIS
239  *
240  * This function overrides the generic pixis_write() function, so that it can
241  * use PIXIS indirect mode if necessary.
242  */
243 void pixis_write(unsigned int reg, u8 value)
244 {
245 	ccsr_gur_t *gur = (void *)CONFIG_SYS_MPC85xx_GUTS_ADDR;
246 
247 	/* Use indirect mode if the mux is currently set to DIU mode */
248 	if ((in_be32(&gur->pmuxcr) & PMUXCR_ELBCDIU_MASK) !=
249 	    PMUXCR_ELBCDIU_NOR16) {
250 		out_8(lbc_lcs0_ba, reg);
251 		out_8(lbc_lcs1_ba, value);
252 		/* Do a read-back to ensure the write completed */
253 		in_8(lbc_lcs1_ba);
254 	} else {
255 		void *p = (void *)PIXIS_BASE;
256 
257 		out_8(p + reg, value);
258 	}
259 }
260 
261 void pixis_bank_reset(void)
262 {
263 	/*
264 	 * For some reason, a PIXIS bank reset does not work if the PIXIS is
265 	 * in indirect mode, so switch to direct mode first.
266 	 */
267 	set_mux_to_lbc();
268 
269 	out_8(&pixis->vctl, 0);
270 	out_8(&pixis->vctl, 1);
271 
272 	while (1);
273 }
274 
275 #ifdef CONFIG_CFI_FLASH_USE_WEAK_ACCESSORS
276 
277 void flash_write8(u8 value, void *addr)
278 {
279 	int sw = set_mux_to_lbc();
280 
281 	__raw_writeb(value, addr);
282 	if (sw) {
283 		/*
284 		 * To ensure the post-write is completed to eLBC, software must
285 		 * perform a dummy read from one valid address from eLBC space
286 		 * before changing the eLBC_DIU from NOR mode to DIU mode.
287 		 * set_mux_to_diu() includes a sync that will ensure the
288 		 * __raw_readb() completes before it switches the mux.
289 		 */
290 		__raw_readb(addr);
291 		set_mux_to_diu();
292 	}
293 }
294 
295 void flash_write16(u16 value, void *addr)
296 {
297 	int sw = set_mux_to_lbc();
298 
299 	__raw_writew(value, addr);
300 	if (sw) {
301 		/*
302 		 * To ensure the post-write is completed to eLBC, software must
303 		 * perform a dummy read from one valid address from eLBC space
304 		 * before changing the eLBC_DIU from NOR mode to DIU mode.
305 		 * set_mux_to_diu() includes a sync that will ensure the
306 		 * __raw_readb() completes before it switches the mux.
307 		 */
308 		__raw_readb(addr);
309 		set_mux_to_diu();
310 	}
311 }
312 
313 void flash_write32(u32 value, void *addr)
314 {
315 	int sw = set_mux_to_lbc();
316 
317 	__raw_writel(value, addr);
318 	if (sw) {
319 		/*
320 		 * To ensure the post-write is completed to eLBC, software must
321 		 * perform a dummy read from one valid address from eLBC space
322 		 * before changing the eLBC_DIU from NOR mode to DIU mode.
323 		 * set_mux_to_diu() includes a sync that will ensure the
324 		 * __raw_readb() completes before it switches the mux.
325 		 */
326 		__raw_readb(addr);
327 		set_mux_to_diu();
328 	}
329 }
330 
331 void flash_write64(u64 value, void *addr)
332 {
333 	int sw = set_mux_to_lbc();
334 	uint32_t *p = addr;
335 
336 	/*
337 	 * There is no __raw_writeq(), so do the write manually.  We don't trust
338 	 * the compiler, so we use inline assembly.
339 	 */
340 	__asm__ __volatile__(
341 		"stw%U0%X0 %2,%0;\n"
342 		"stw%U1%X1 %3,%1;\n"
343 		: "=m" (*p), "=m" (*(p + 1))
344 		: "r" ((uint32_t) (value >> 32)), "r" ((uint32_t) (value)));
345 
346 	if (sw) {
347 		/*
348 		 * To ensure the post-write is completed to eLBC, software must
349 		 * perform a dummy read from one valid address from eLBC space
350 		 * before changing the eLBC_DIU from NOR mode to DIU mode.  We
351 		 * read addr+4 because we just wrote to addr+4, so that's how we
352 		 * maintain execution order.  set_mux_to_diu() includes a sync
353 		 * that will ensure the __raw_readb() completes before it
354 		 * switches the mux.
355 		 */
356 		__raw_readb(addr + 4);
357 		set_mux_to_diu();
358 	}
359 }
360 
361 u8 flash_read8(void *addr)
362 {
363 	u8 ret;
364 
365 	int sw = set_mux_to_lbc();
366 
367 	ret = __raw_readb(addr);
368 	if (sw)
369 		set_mux_to_diu();
370 
371 	return ret;
372 }
373 
374 u16 flash_read16(void *addr)
375 {
376 	u16 ret;
377 
378 	int sw = set_mux_to_lbc();
379 
380 	ret = __raw_readw(addr);
381 	if (sw)
382 		set_mux_to_diu();
383 
384 	return ret;
385 }
386 
387 u32 flash_read32(void *addr)
388 {
389 	u32 ret;
390 
391 	int sw = set_mux_to_lbc();
392 
393 	ret = __raw_readl(addr);
394 	if (sw)
395 		set_mux_to_diu();
396 
397 	return ret;
398 }
399 
400 u64 flash_read64(void *addr)
401 {
402 	u64 ret;
403 
404 	int sw = set_mux_to_lbc();
405 
406 	/* There is no __raw_readq(), so do the read manually */
407 	ret = *(volatile u64 *)addr;
408 	if (sw)
409 		set_mux_to_diu();
410 
411 	return ret;
412 }
413 
414 #endif
415