1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 2007,2008 Freescale Semiconductor, Inc. All rights reserved.
4 *
5 * Author: John Rigby <jrigby@freescale.com>
6 *
7 * Description:
8 * MPC512x Shared code
9 */
10
11 #include <linux/clk.h>
12 #include <linux/kernel.h>
13 #include <linux/io.h>
14 #include <linux/irq.h>
15 #include <linux/of_address.h>
16 #include <linux/of_platform.h>
17 #include <linux/fsl-diu-fb.h>
18 #include <linux/memblock.h>
19 #include <sysdev/fsl_soc.h>
20
21 #include <asm/cacheflush.h>
22 #include <asm/machdep.h>
23 #include <asm/ipic.h>
24 #include <asm/time.h>
25 #include <asm/mpc5121.h>
26 #include <asm/mpc52xx_psc.h>
27
28 #include "mpc512x.h"
29
30 static struct mpc512x_reset_module __iomem *reset_module_base;
31
mpc512x_restart_init(void)32 static void __init mpc512x_restart_init(void)
33 {
34 struct device_node *np;
35 const char *reset_compat;
36
37 reset_compat = mpc512x_select_reset_compat();
38 np = of_find_compatible_node(NULL, NULL, reset_compat);
39 if (!np)
40 return;
41
42 reset_module_base = of_iomap(np, 0);
43 of_node_put(np);
44 }
45
mpc512x_restart(char * cmd)46 void __noreturn mpc512x_restart(char *cmd)
47 {
48 if (reset_module_base) {
49 /* Enable software reset "RSTE" */
50 out_be32(&reset_module_base->rpr, 0x52535445);
51 /* Set software hard reset */
52 out_be32(&reset_module_base->rcr, 0x2);
53 } else {
54 pr_err("Restart module not mapped.\n");
55 }
56 for (;;)
57 ;
58 }
59
60 struct fsl_diu_shared_fb {
61 u8 gamma[0x300]; /* 32-bit aligned! */
62 struct diu_ad ad0; /* 32-bit aligned! */
63 phys_addr_t fb_phys;
64 size_t fb_len;
65 bool in_use;
66 };
67
68 /* receives a pixel clock spec in pico seconds, adjusts the DIU clock rate */
mpc512x_set_pixel_clock(unsigned int pixclock)69 static void mpc512x_set_pixel_clock(unsigned int pixclock)
70 {
71 struct device_node *np;
72 struct clk *clk_diu;
73 unsigned long epsilon, minpixclock, maxpixclock;
74 unsigned long offset, want, got, delta;
75
76 /* lookup and enable the DIU clock */
77 np = of_find_compatible_node(NULL, NULL, "fsl,mpc5121-diu");
78 if (!np) {
79 pr_err("Could not find DIU device tree node.\n");
80 return;
81 }
82 clk_diu = of_clk_get(np, 0);
83 if (IS_ERR(clk_diu)) {
84 /* backwards compat with device trees that lack clock specs */
85 clk_diu = clk_get_sys(np->name, "ipg");
86 }
87 of_node_put(np);
88 if (IS_ERR(clk_diu)) {
89 pr_err("Could not lookup DIU clock.\n");
90 return;
91 }
92 if (clk_prepare_enable(clk_diu)) {
93 pr_err("Could not enable DIU clock.\n");
94 return;
95 }
96
97 /*
98 * convert the picoseconds spec into the desired clock rate,
99 * determine the acceptable clock range for the monitor (+/- 5%),
100 * do the calculation in steps to avoid integer overflow
101 */
102 pr_debug("DIU pixclock in ps - %u\n", pixclock);
103 pixclock = (1000000000 / pixclock) * 1000;
104 pr_debug("DIU pixclock freq - %u\n", pixclock);
105 epsilon = pixclock / 20; /* pixclock * 0.05 */
106 pr_debug("DIU deviation - %lu\n", epsilon);
107 minpixclock = pixclock - epsilon;
108 maxpixclock = pixclock + epsilon;
109 pr_debug("DIU minpixclock - %lu\n", minpixclock);
110 pr_debug("DIU maxpixclock - %lu\n", maxpixclock);
111
112 /*
113 * check whether the DIU supports the desired pixel clock
114 *
115 * - simply request the desired clock and see what the
116 * platform's clock driver will make of it, assuming that it
117 * will setup the best approximation of the requested value
118 * - try other candidate frequencies in the order of decreasing
119 * preference (i.e. with increasing distance from the desired
120 * pixel clock, and checking the lower frequency before the
121 * higher frequency to not overload the hardware) until the
122 * first match is found -- any potential subsequent match
123 * would only be as good as the former match or typically
124 * would be less preferrable
125 *
126 * the offset increment of pixelclock divided by 64 is an
127 * arbitrary choice -- it's simple to calculate, in the typical
128 * case we expect the first check to succeed already, in the
129 * worst case seven frequencies get tested (the exact center and
130 * three more values each to the left and to the right) before
131 * the 5% tolerance window is exceeded, resulting in fast enough
132 * execution yet high enough probability of finding a suitable
133 * value, while the error rate will be in the order of single
134 * percents
135 */
136 for (offset = 0; offset <= epsilon; offset += pixclock / 64) {
137 want = pixclock - offset;
138 pr_debug("DIU checking clock - %lu\n", want);
139 clk_set_rate(clk_diu, want);
140 got = clk_get_rate(clk_diu);
141 delta = abs(pixclock - got);
142 if (delta < epsilon)
143 break;
144 if (!offset)
145 continue;
146 want = pixclock + offset;
147 pr_debug("DIU checking clock - %lu\n", want);
148 clk_set_rate(clk_diu, want);
149 got = clk_get_rate(clk_diu);
150 delta = abs(pixclock - got);
151 if (delta < epsilon)
152 break;
153 }
154 if (offset <= epsilon) {
155 pr_debug("DIU clock accepted - %lu\n", want);
156 pr_debug("DIU pixclock want %u, got %lu, delta %lu, eps %lu\n",
157 pixclock, got, delta, epsilon);
158 return;
159 }
160 pr_warn("DIU pixclock auto search unsuccessful\n");
161
162 /*
163 * what is the most appropriate action to take when the search
164 * for an available pixel clock which is acceptable to the
165 * monitor has failed? disable the DIU (clock) or just provide
166 * a "best effort"? we go with the latter
167 */
168 pr_warn("DIU pixclock best effort fallback (backend's choice)\n");
169 clk_set_rate(clk_diu, pixclock);
170 got = clk_get_rate(clk_diu);
171 delta = abs(pixclock - got);
172 pr_debug("DIU pixclock want %u, got %lu, delta %lu, eps %lu\n",
173 pixclock, got, delta, epsilon);
174 }
175
176 static enum fsl_diu_monitor_port
mpc512x_valid_monitor_port(enum fsl_diu_monitor_port port)177 mpc512x_valid_monitor_port(enum fsl_diu_monitor_port port)
178 {
179 return FSL_DIU_PORT_DVI;
180 }
181
182 static struct fsl_diu_shared_fb __attribute__ ((__aligned__(8))) diu_shared_fb;
183
mpc512x_free_bootmem(struct page * page)184 static inline void mpc512x_free_bootmem(struct page *page)
185 {
186 BUG_ON(PageTail(page));
187 BUG_ON(page_ref_count(page) > 1);
188 free_reserved_page(page);
189 }
190
mpc512x_release_bootmem(void)191 static void mpc512x_release_bootmem(void)
192 {
193 unsigned long addr = diu_shared_fb.fb_phys & PAGE_MASK;
194 unsigned long size = diu_shared_fb.fb_len;
195 unsigned long start, end;
196
197 if (diu_shared_fb.in_use) {
198 start = PFN_UP(addr);
199 end = PFN_DOWN(addr + size);
200
201 for (; start < end; start++)
202 mpc512x_free_bootmem(pfn_to_page(start));
203
204 diu_shared_fb.in_use = false;
205 }
206 diu_ops.release_bootmem = NULL;
207 }
208
209 /*
210 * Check if DIU was pre-initialized. If so, perform steps
211 * needed to continue displaying through the whole boot process.
212 * Move area descriptor and gamma table elsewhere, they are
213 * destroyed by bootmem allocator otherwise. The frame buffer
214 * address range will be reserved in setup_arch() after bootmem
215 * allocator is up.
216 */
mpc512x_init_diu(void)217 static void __init mpc512x_init_diu(void)
218 {
219 struct device_node *np;
220 struct diu __iomem *diu_reg;
221 phys_addr_t desc;
222 void __iomem *vaddr;
223 unsigned long mode, pix_fmt, res, bpp;
224 unsigned long dst;
225
226 np = of_find_compatible_node(NULL, NULL, "fsl,mpc5121-diu");
227 if (!np) {
228 pr_err("No DIU node\n");
229 return;
230 }
231
232 diu_reg = of_iomap(np, 0);
233 of_node_put(np);
234 if (!diu_reg) {
235 pr_err("Can't map DIU\n");
236 return;
237 }
238
239 mode = in_be32(&diu_reg->diu_mode);
240 if (mode == MFB_MODE0) {
241 pr_info("%s: DIU OFF\n", __func__);
242 goto out;
243 }
244
245 desc = in_be32(&diu_reg->desc[0]);
246 vaddr = ioremap(desc, sizeof(struct diu_ad));
247 if (!vaddr) {
248 pr_err("Can't map DIU area desc.\n");
249 goto out;
250 }
251 memcpy(&diu_shared_fb.ad0, vaddr, sizeof(struct diu_ad));
252 /* flush fb area descriptor */
253 dst = (unsigned long)&diu_shared_fb.ad0;
254 flush_dcache_range(dst, dst + sizeof(struct diu_ad) - 1);
255
256 res = in_be32(&diu_reg->disp_size);
257 pix_fmt = in_le32(vaddr);
258 bpp = ((pix_fmt >> 16) & 0x3) + 1;
259 diu_shared_fb.fb_phys = in_le32(vaddr + 4);
260 diu_shared_fb.fb_len = ((res & 0xfff0000) >> 16) * (res & 0xfff) * bpp;
261 diu_shared_fb.in_use = true;
262 iounmap(vaddr);
263
264 desc = in_be32(&diu_reg->gamma);
265 vaddr = ioremap(desc, sizeof(diu_shared_fb.gamma));
266 if (!vaddr) {
267 pr_err("Can't map DIU area desc.\n");
268 diu_shared_fb.in_use = false;
269 goto out;
270 }
271 memcpy(&diu_shared_fb.gamma, vaddr, sizeof(diu_shared_fb.gamma));
272 /* flush gamma table */
273 dst = (unsigned long)&diu_shared_fb.gamma;
274 flush_dcache_range(dst, dst + sizeof(diu_shared_fb.gamma) - 1);
275
276 iounmap(vaddr);
277 out_be32(&diu_reg->gamma, virt_to_phys(&diu_shared_fb.gamma));
278 out_be32(&diu_reg->desc[1], 0);
279 out_be32(&diu_reg->desc[2], 0);
280 out_be32(&diu_reg->desc[0], virt_to_phys(&diu_shared_fb.ad0));
281
282 out:
283 iounmap(diu_reg);
284 }
285
mpc512x_setup_diu(void)286 static void __init mpc512x_setup_diu(void)
287 {
288 int ret;
289
290 /*
291 * We do not allocate and configure new area for bitmap buffer
292 * because it would require copying bitmap data (splash image)
293 * and so negatively affect boot time. Instead we reserve the
294 * already configured frame buffer area so that it won't be
295 * destroyed. The starting address of the area to reserve and
296 * also it's length is passed to memblock_reserve(). It will be
297 * freed later on first open of fbdev, when splash image is not
298 * needed any more.
299 */
300 if (diu_shared_fb.in_use) {
301 ret = memblock_reserve(diu_shared_fb.fb_phys,
302 diu_shared_fb.fb_len);
303 if (ret) {
304 pr_err("%s: reserve bootmem failed\n", __func__);
305 diu_shared_fb.in_use = false;
306 }
307 }
308
309 diu_ops.set_pixel_clock = mpc512x_set_pixel_clock;
310 diu_ops.valid_monitor_port = mpc512x_valid_monitor_port;
311 diu_ops.release_bootmem = mpc512x_release_bootmem;
312 }
313
mpc512x_init_IRQ(void)314 void __init mpc512x_init_IRQ(void)
315 {
316 struct device_node *np;
317
318 np = of_find_compatible_node(NULL, NULL, "fsl,mpc5121-ipic");
319 if (!np)
320 return;
321
322 ipic_init(np, 0);
323 of_node_put(np);
324
325 /*
326 * Initialize the default interrupt mapping priorities,
327 * in case the boot rom changed something on us.
328 */
329 ipic_set_default_priority();
330 }
331
332 /*
333 * Nodes to do bus probe on, soc and localbus
334 */
335 static const struct of_device_id of_bus_ids[] __initconst = {
336 { .compatible = "fsl,mpc5121-immr", },
337 { .compatible = "fsl,mpc5121-localbus", },
338 { .compatible = "fsl,mpc5121-mbx", },
339 { .compatible = "fsl,mpc5121-nfc", },
340 { .compatible = "fsl,mpc5121-sram", },
341 { .compatible = "fsl,mpc5121-pci", },
342 { .compatible = "gpio-leds", },
343 {},
344 };
345
mpc512x_declare_of_platform_devices(void)346 static void __init mpc512x_declare_of_platform_devices(void)
347 {
348 if (of_platform_bus_probe(NULL, of_bus_ids, NULL))
349 printk(KERN_ERR __FILE__ ": "
350 "Error while probing of_platform bus\n");
351 }
352
353 #define DEFAULT_FIFO_SIZE 16
354
mpc512x_select_psc_compat(void)355 const char *__init mpc512x_select_psc_compat(void)
356 {
357 if (of_machine_is_compatible("fsl,mpc5121"))
358 return "fsl,mpc5121-psc";
359
360 if (of_machine_is_compatible("fsl,mpc5125"))
361 return "fsl,mpc5125-psc";
362
363 return NULL;
364 }
365
mpc512x_select_reset_compat(void)366 const char *__init mpc512x_select_reset_compat(void)
367 {
368 if (of_machine_is_compatible("fsl,mpc5121"))
369 return "fsl,mpc5121-reset";
370
371 if (of_machine_is_compatible("fsl,mpc5125"))
372 return "fsl,mpc5125-reset";
373
374 return NULL;
375 }
376
get_fifo_size(struct device_node * np,char * prop_name)377 static unsigned int __init get_fifo_size(struct device_node *np,
378 char *prop_name)
379 {
380 const unsigned int *fp;
381
382 fp = of_get_property(np, prop_name, NULL);
383 if (fp)
384 return *fp;
385
386 pr_warn("no %s property in %pOF node, defaulting to %d\n",
387 prop_name, np, DEFAULT_FIFO_SIZE);
388
389 return DEFAULT_FIFO_SIZE;
390 }
391
392 #define FIFOC(_base) ((struct mpc512x_psc_fifo __iomem *) \
393 ((u32)(_base) + sizeof(struct mpc52xx_psc)))
394
395 /* Init PSC FIFO space for TX and RX slices */
mpc512x_psc_fifo_init(void)396 static void __init mpc512x_psc_fifo_init(void)
397 {
398 struct device_node *np;
399 void __iomem *psc;
400 unsigned int tx_fifo_size;
401 unsigned int rx_fifo_size;
402 const char *psc_compat;
403 int fifobase = 0; /* current fifo address in 32 bit words */
404
405 psc_compat = mpc512x_select_psc_compat();
406 if (!psc_compat) {
407 pr_err("%s: no compatible devices found\n", __func__);
408 return;
409 }
410
411 for_each_compatible_node(np, NULL, psc_compat) {
412 tx_fifo_size = get_fifo_size(np, "fsl,tx-fifo-size");
413 rx_fifo_size = get_fifo_size(np, "fsl,rx-fifo-size");
414
415 /* size in register is in 4 byte units */
416 tx_fifo_size /= 4;
417 rx_fifo_size /= 4;
418 if (!tx_fifo_size)
419 tx_fifo_size = 1;
420 if (!rx_fifo_size)
421 rx_fifo_size = 1;
422
423 psc = of_iomap(np, 0);
424 if (!psc) {
425 pr_err("%s: Can't map %pOF device\n",
426 __func__, np);
427 continue;
428 }
429
430 /* FIFO space is 4KiB, check if requested size is available */
431 if ((fifobase + tx_fifo_size + rx_fifo_size) > 0x1000) {
432 pr_err("%s: no fifo space available for %pOF\n",
433 __func__, np);
434 iounmap(psc);
435 /*
436 * chances are that another device requests less
437 * fifo space, so we continue.
438 */
439 continue;
440 }
441
442 /* set tx and rx fifo size registers */
443 out_be32(&FIFOC(psc)->txsz, (fifobase << 16) | tx_fifo_size);
444 fifobase += tx_fifo_size;
445 out_be32(&FIFOC(psc)->rxsz, (fifobase << 16) | rx_fifo_size);
446 fifobase += rx_fifo_size;
447
448 /* reset and enable the slices */
449 out_be32(&FIFOC(psc)->txcmd, 0x80);
450 out_be32(&FIFOC(psc)->txcmd, 0x01);
451 out_be32(&FIFOC(psc)->rxcmd, 0x80);
452 out_be32(&FIFOC(psc)->rxcmd, 0x01);
453
454 iounmap(psc);
455 }
456 }
457
mpc512x_init_early(void)458 void __init mpc512x_init_early(void)
459 {
460 mpc512x_restart_init();
461 if (IS_ENABLED(CONFIG_FB_FSL_DIU))
462 mpc512x_init_diu();
463 }
464
mpc512x_init(void)465 void __init mpc512x_init(void)
466 {
467 mpc5121_clk_init();
468 mpc512x_declare_of_platform_devices();
469 mpc512x_psc_fifo_init();
470 }
471
mpc512x_setup_arch(void)472 void __init mpc512x_setup_arch(void)
473 {
474 if (IS_ENABLED(CONFIG_FB_FSL_DIU))
475 mpc512x_setup_diu();
476 }
477
478 /**
479 * mpc512x_cs_config - Setup chip select configuration
480 * @cs: chip select number
481 * @val: chip select configuration value
482 *
483 * Perform chip select configuration for devices on LocalPlus Bus.
484 * Intended to dynamically reconfigure the chip select parameters
485 * for configurable devices on the bus.
486 */
mpc512x_cs_config(unsigned int cs,u32 val)487 int mpc512x_cs_config(unsigned int cs, u32 val)
488 {
489 static struct mpc512x_lpc __iomem *lpc;
490 struct device_node *np;
491
492 if (cs > 7)
493 return -EINVAL;
494
495 if (!lpc) {
496 np = of_find_compatible_node(NULL, NULL, "fsl,mpc5121-lpc");
497 lpc = of_iomap(np, 0);
498 of_node_put(np);
499 if (!lpc)
500 return -ENOMEM;
501 }
502
503 out_be32(&lpc->cs_cfg[cs], val);
504 return 0;
505 }
506 EXPORT_SYMBOL(mpc512x_cs_config);
507