1 /*
2  *  Port on Texas Instruments TMS320C6x architecture
3  *
4  *  Copyright (C) 2004, 2006, 2009, 2010, 2011 Texas Instruments Incorporated
5  *  Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com)
6  *
7  *  This program is free software; you can redistribute it and/or modify
8  *  it under the terms of the GNU General Public License version 2 as
9  *  published by the Free Software Foundation.
10  */
11 #include <linux/dma-mapping.h>
12 #include <linux/memblock.h>
13 #include <linux/seq_file.h>
14 #include <linux/bootmem.h>
15 #include <linux/clkdev.h>
16 #include <linux/initrd.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/of_fdt.h>
20 #include <linux/string.h>
21 #include <linux/errno.h>
22 #include <linux/cache.h>
23 #include <linux/delay.h>
24 #include <linux/sched.h>
25 #include <linux/clk.h>
26 #include <linux/cpu.h>
27 #include <linux/fs.h>
28 #include <linux/of.h>
29 #include <linux/console.h>
30 #include <linux/screen_info.h>
31 
32 #include <asm/sections.h>
33 #include <asm/div64.h>
34 #include <asm/setup.h>
35 #include <asm/dscr.h>
36 #include <asm/clock.h>
37 #include <asm/soc.h>
38 #include <asm/special_insns.h>
39 
40 static const char *c6x_soc_name;
41 
42 struct screen_info screen_info;
43 
44 int c6x_num_cores;
45 EXPORT_SYMBOL_GPL(c6x_num_cores);
46 
47 unsigned int c6x_silicon_rev;
48 EXPORT_SYMBOL_GPL(c6x_silicon_rev);
49 
50 /*
51  * Device status register. This holds information
52  * about device configuration needed by some drivers.
53  */
54 unsigned int c6x_devstat;
55 EXPORT_SYMBOL_GPL(c6x_devstat);
56 
57 /*
58  * Some SoCs have fuse registers holding a unique MAC
59  * address. This is parsed out of the device tree with
60  * the resulting MAC being held here.
61  */
62 unsigned char c6x_fuse_mac[6];
63 
64 unsigned long memory_start;
65 unsigned long memory_end;
66 EXPORT_SYMBOL(memory_end);
67 
68 unsigned long ram_start;
69 unsigned long ram_end;
70 
71 /* Uncached memory for DMA consistent use (memdma=) */
72 static unsigned long dma_start __initdata;
73 static unsigned long dma_size __initdata;
74 
75 struct cpuinfo_c6x {
76 	const char *cpu_name;
77 	const char *cpu_voltage;
78 	const char *mmu;
79 	const char *fpu;
80 	char *cpu_rev;
81 	unsigned int core_id;
82 	char __cpu_rev[5];
83 };
84 
85 static DEFINE_PER_CPU(struct cpuinfo_c6x, cpu_data);
86 
87 unsigned int ticks_per_ns_scaled;
88 EXPORT_SYMBOL(ticks_per_ns_scaled);
89 
90 unsigned int c6x_core_freq;
91 
get_cpuinfo(void)92 static void __init get_cpuinfo(void)
93 {
94 	unsigned cpu_id, rev_id, csr;
95 	struct clk *coreclk = clk_get_sys(NULL, "core");
96 	unsigned long core_khz;
97 	u64 tmp;
98 	struct cpuinfo_c6x *p;
99 	struct device_node *node, *np;
100 
101 	p = &per_cpu(cpu_data, smp_processor_id());
102 
103 	if (!IS_ERR(coreclk))
104 		c6x_core_freq = clk_get_rate(coreclk);
105 	else {
106 		printk(KERN_WARNING
107 		       "Cannot find core clock frequency. Using 700MHz\n");
108 		c6x_core_freq = 700000000;
109 	}
110 
111 	core_khz = c6x_core_freq / 1000;
112 
113 	tmp = (uint64_t)core_khz << C6X_NDELAY_SCALE;
114 	do_div(tmp, 1000000);
115 	ticks_per_ns_scaled = tmp;
116 
117 	csr = get_creg(CSR);
118 	cpu_id = csr >> 24;
119 	rev_id = (csr >> 16) & 0xff;
120 
121 	p->mmu = "none";
122 	p->fpu = "none";
123 	p->cpu_voltage = "unknown";
124 
125 	switch (cpu_id) {
126 	case 0:
127 		p->cpu_name = "C67x";
128 		p->fpu = "yes";
129 		break;
130 	case 2:
131 		p->cpu_name = "C62x";
132 		break;
133 	case 8:
134 		p->cpu_name = "C64x";
135 		break;
136 	case 12:
137 		p->cpu_name = "C64x";
138 		break;
139 	case 16:
140 		p->cpu_name = "C64x+";
141 		p->cpu_voltage = "1.2";
142 		break;
143 	case 21:
144 		p->cpu_name = "C66X";
145 		p->cpu_voltage = "1.2";
146 		break;
147 	default:
148 		p->cpu_name = "unknown";
149 		break;
150 	}
151 
152 	if (cpu_id < 16) {
153 		switch (rev_id) {
154 		case 0x1:
155 			if (cpu_id > 8) {
156 				p->cpu_rev = "DM640/DM641/DM642/DM643";
157 				p->cpu_voltage = "1.2 - 1.4";
158 			} else {
159 				p->cpu_rev = "C6201";
160 				p->cpu_voltage = "2.5";
161 			}
162 			break;
163 		case 0x2:
164 			p->cpu_rev = "C6201B/C6202/C6211";
165 			p->cpu_voltage = "1.8";
166 			break;
167 		case 0x3:
168 			p->cpu_rev = "C6202B/C6203/C6204/C6205";
169 			p->cpu_voltage = "1.5";
170 			break;
171 		case 0x201:
172 			p->cpu_rev = "C6701 revision 0 (early CPU)";
173 			p->cpu_voltage = "1.8";
174 			break;
175 		case 0x202:
176 			p->cpu_rev = "C6701/C6711/C6712";
177 			p->cpu_voltage = "1.8";
178 			break;
179 		case 0x801:
180 			p->cpu_rev = "C64x";
181 			p->cpu_voltage = "1.5";
182 			break;
183 		default:
184 			p->cpu_rev = "unknown";
185 		}
186 	} else {
187 		p->cpu_rev = p->__cpu_rev;
188 		snprintf(p->__cpu_rev, sizeof(p->__cpu_rev), "0x%x", cpu_id);
189 	}
190 
191 	p->core_id = get_coreid();
192 
193 	node = of_find_node_by_name(NULL, "cpus");
194 	if (node) {
195 		for_each_child_of_node(node, np)
196 			if (!strcmp("cpu", np->name))
197 				++c6x_num_cores;
198 		of_node_put(node);
199 	}
200 
201 	node = of_find_node_by_name(NULL, "soc");
202 	if (node) {
203 		if (of_property_read_string(node, "model", &c6x_soc_name))
204 			c6x_soc_name = "unknown";
205 		of_node_put(node);
206 	} else
207 		c6x_soc_name = "unknown";
208 
209 	printk(KERN_INFO "CPU%d: %s rev %s, %s volts, %uMHz\n",
210 	       p->core_id, p->cpu_name, p->cpu_rev,
211 	       p->cpu_voltage, c6x_core_freq / 1000000);
212 }
213 
214 /*
215  * Early parsing of the command line
216  */
217 static u32 mem_size __initdata;
218 
219 /* "mem=" parsing. */
early_mem(char * p)220 static int __init early_mem(char *p)
221 {
222 	if (!p)
223 		return -EINVAL;
224 
225 	mem_size = memparse(p, &p);
226 	/* don't remove all of memory when handling "mem={invalid}" */
227 	if (mem_size == 0)
228 		return -EINVAL;
229 
230 	return 0;
231 }
232 early_param("mem", early_mem);
233 
234 /* "memdma=<size>[@<address>]" parsing. */
early_memdma(char * p)235 static int __init early_memdma(char *p)
236 {
237 	if (!p)
238 		return -EINVAL;
239 
240 	dma_size = memparse(p, &p);
241 	if (*p == '@')
242 		dma_start = memparse(p, &p);
243 
244 	return 0;
245 }
246 early_param("memdma", early_memdma);
247 
c6x_add_memory(phys_addr_t start,unsigned long size)248 int __init c6x_add_memory(phys_addr_t start, unsigned long size)
249 {
250 	static int ram_found __initdata;
251 
252 	/* We only handle one bank (the one with PAGE_OFFSET) for now */
253 	if (ram_found)
254 		return -EINVAL;
255 
256 	if (start > PAGE_OFFSET || PAGE_OFFSET >= (start + size))
257 		return 0;
258 
259 	ram_start = start;
260 	ram_end = start + size;
261 
262 	ram_found = 1;
263 	return 0;
264 }
265 
266 /*
267  * Do early machine setup and device tree parsing. This is called very
268  * early on the boot process.
269  */
machine_init(unsigned long dt_ptr)270 notrace void __init machine_init(unsigned long dt_ptr)
271 {
272 	void *dtb = __va(dt_ptr);
273 	void *fdt = _fdt_start;
274 
275 	/* interrupts must be masked */
276 	set_creg(IER, 2);
277 
278 	/*
279 	 * Set the Interrupt Service Table (IST) to the beginning of the
280 	 * vector table.
281 	 */
282 	set_ist(_vectors_start);
283 
284 	/*
285 	 * dtb is passed in from bootloader.
286 	 * fdt is linked in blob.
287 	 */
288 	if (dtb && dtb != fdt)
289 		fdt = dtb;
290 
291 	/* Do some early initialization based on the flat device tree */
292 	early_init_dt_scan(fdt);
293 
294 	parse_early_param();
295 }
296 
setup_arch(char ** cmdline_p)297 void __init setup_arch(char **cmdline_p)
298 {
299 	int bootmap_size;
300 	struct memblock_region *reg;
301 
302 	printk(KERN_INFO "Initializing kernel\n");
303 
304 	/* Initialize command line */
305 	*cmdline_p = boot_command_line;
306 
307 	memory_end = ram_end;
308 	memory_end &= ~(PAGE_SIZE - 1);
309 
310 	if (mem_size && (PAGE_OFFSET + PAGE_ALIGN(mem_size)) < memory_end)
311 		memory_end = PAGE_OFFSET + PAGE_ALIGN(mem_size);
312 
313 	/* add block that this kernel can use */
314 	memblock_add(PAGE_OFFSET, memory_end - PAGE_OFFSET);
315 
316 	/* reserve kernel text/data/bss */
317 	memblock_reserve(PAGE_OFFSET,
318 			 PAGE_ALIGN((unsigned long)&_end - PAGE_OFFSET));
319 
320 	if (dma_size) {
321 		/* align to cacheability granularity */
322 		dma_size = CACHE_REGION_END(dma_size);
323 
324 		if (!dma_start)
325 			dma_start = memory_end - dma_size;
326 
327 		/* align to cacheability granularity */
328 		dma_start = CACHE_REGION_START(dma_start);
329 
330 		/* reserve DMA memory taken from kernel memory */
331 		if (memblock_is_region_memory(dma_start, dma_size))
332 			memblock_reserve(dma_start, dma_size);
333 	}
334 
335 	memory_start = PAGE_ALIGN((unsigned int) &_end);
336 
337 	printk(KERN_INFO "Memory Start=%08lx, Memory End=%08lx\n",
338 	       memory_start, memory_end);
339 
340 #ifdef CONFIG_BLK_DEV_INITRD
341 	/*
342 	 * Reserve initrd memory if in kernel memory.
343 	 */
344 	if (initrd_start < initrd_end)
345 		if (memblock_is_region_memory(initrd_start,
346 					      initrd_end - initrd_start))
347 			memblock_reserve(initrd_start,
348 					 initrd_end - initrd_start);
349 #endif
350 
351 	init_mm.start_code = (unsigned long) &_stext;
352 	init_mm.end_code   = (unsigned long) &_etext;
353 	init_mm.end_data   = memory_start;
354 	init_mm.brk        = memory_start;
355 
356 	/*
357 	 * Give all the memory to the bootmap allocator,  tell it to put the
358 	 * boot mem_map at the start of memory
359 	 */
360 	bootmap_size = init_bootmem_node(NODE_DATA(0),
361 					 memory_start >> PAGE_SHIFT,
362 					 PAGE_OFFSET >> PAGE_SHIFT,
363 					 memory_end >> PAGE_SHIFT);
364 	memblock_reserve(memory_start, bootmap_size);
365 
366 	unflatten_device_tree();
367 
368 	c6x_cache_init();
369 
370 	/* Set the whole external memory as non-cacheable */
371 	disable_caching(ram_start, ram_end - 1);
372 
373 	/* Set caching of external RAM used by Linux */
374 	for_each_memblock(memory, reg)
375 		enable_caching(CACHE_REGION_START(reg->base),
376 			       CACHE_REGION_START(reg->base + reg->size - 1));
377 
378 #ifdef CONFIG_BLK_DEV_INITRD
379 	/*
380 	 * Enable caching for initrd which falls outside kernel memory.
381 	 */
382 	if (initrd_start < initrd_end) {
383 		if (!memblock_is_region_memory(initrd_start,
384 					       initrd_end - initrd_start))
385 			enable_caching(CACHE_REGION_START(initrd_start),
386 				       CACHE_REGION_START(initrd_end - 1));
387 	}
388 #endif
389 
390 	/*
391 	 * Disable caching for dma coherent memory taken from kernel memory.
392 	 */
393 	if (dma_size && memblock_is_region_memory(dma_start, dma_size))
394 		disable_caching(dma_start,
395 				CACHE_REGION_START(dma_start + dma_size - 1));
396 
397 	/* Initialize the coherent memory allocator */
398 	coherent_mem_init(dma_start, dma_size);
399 
400 	/*
401 	 * Free all memory as a starting point.
402 	 */
403 	free_bootmem(PAGE_OFFSET, memory_end - PAGE_OFFSET);
404 
405 	/*
406 	 * Then reserve memory which is already being used.
407 	 */
408 	for_each_memblock(reserved, reg) {
409 		pr_debug("reserved - 0x%08x-0x%08x\n",
410 			 (u32) reg->base, (u32) reg->size);
411 		reserve_bootmem(reg->base, reg->size, BOOTMEM_DEFAULT);
412 	}
413 
414 	max_low_pfn = PFN_DOWN(memory_end);
415 	min_low_pfn = PFN_UP(memory_start);
416 	max_mapnr = max_low_pfn - min_low_pfn;
417 
418 	/* Get kmalloc into gear */
419 	paging_init();
420 
421 	/*
422 	 * Probe for Device State Configuration Registers.
423 	 * We have to do this early in case timer needs to be enabled
424 	 * through DSCR.
425 	 */
426 	dscr_probe();
427 
428 	/* We do this early for timer and core clock frequency */
429 	c64x_setup_clocks();
430 
431 	/* Get CPU info */
432 	get_cpuinfo();
433 
434 #if defined(CONFIG_VT) && defined(CONFIG_DUMMY_CONSOLE)
435 	conswitchp = &dummy_con;
436 #endif
437 }
438 
439 #define cpu_to_ptr(n) ((void *)((long)(n)+1))
440 #define ptr_to_cpu(p) ((long)(p) - 1)
441 
show_cpuinfo(struct seq_file * m,void * v)442 static int show_cpuinfo(struct seq_file *m, void *v)
443 {
444 	int n = ptr_to_cpu(v);
445 	struct cpuinfo_c6x *p = &per_cpu(cpu_data, n);
446 
447 	if (n == 0) {
448 		seq_printf(m,
449 			   "soc\t\t: %s\n"
450 			   "soc revision\t: 0x%x\n"
451 			   "soc cores\t: %d\n",
452 			   c6x_soc_name, c6x_silicon_rev, c6x_num_cores);
453 	}
454 
455 	seq_printf(m,
456 		   "\n"
457 		   "processor\t: %d\n"
458 		   "cpu\t\t: %s\n"
459 		   "core revision\t: %s\n"
460 		   "core voltage\t: %s\n"
461 		   "core id\t\t: %d\n"
462 		   "mmu\t\t: %s\n"
463 		   "fpu\t\t: %s\n"
464 		   "cpu MHz\t\t: %u\n"
465 		   "bogomips\t: %lu.%02lu\n\n",
466 		   n,
467 		   p->cpu_name, p->cpu_rev, p->cpu_voltage,
468 		   p->core_id, p->mmu, p->fpu,
469 		   (c6x_core_freq + 500000) / 1000000,
470 		   (loops_per_jiffy/(500000/HZ)),
471 		   (loops_per_jiffy/(5000/HZ))%100);
472 
473 	return 0;
474 }
475 
c_start(struct seq_file * m,loff_t * pos)476 static void *c_start(struct seq_file *m, loff_t *pos)
477 {
478 	return *pos < nr_cpu_ids ? cpu_to_ptr(*pos) : NULL;
479 }
c_next(struct seq_file * m,void * v,loff_t * pos)480 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
481 {
482 	++*pos;
483 	return NULL;
484 }
c_stop(struct seq_file * m,void * v)485 static void c_stop(struct seq_file *m, void *v)
486 {
487 }
488 
489 const struct seq_operations cpuinfo_op = {
490 	c_start,
491 	c_stop,
492 	c_next,
493 	show_cpuinfo
494 };
495 
496 static struct cpu cpu_devices[NR_CPUS];
497 
topology_init(void)498 static int __init topology_init(void)
499 {
500 	int i;
501 
502 	for_each_present_cpu(i)
503 		register_cpu(&cpu_devices[i], i);
504 
505 	return 0;
506 }
507 
508 subsys_initcall(topology_init);
509