This client driver allows you to use a GPIO pin as a source for PPS
[linux-2.6/next.git] / arch / arm / kernel / tcm.c
blob30e302d33e0add9d51e5aeb1261ad350d935c9d4
1 /*
2 * Copyright (C) 2008-2009 ST-Ericsson AB
3 * License terms: GNU General Public License (GPL) version 2
4 * TCM memory handling for ARM systems
6 * Author: Linus Walleij <linus.walleij@stericsson.com>
7 * Author: Rickard Andersson <rickard.andersson@stericsson.com>
8 */
9 #include <linux/init.h>
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/stddef.h>
13 #include <linux/ioport.h>
14 #include <linux/genalloc.h>
15 #include <linux/string.h> /* memcpy */
16 #include <asm/cputype.h>
17 #include <asm/mach/map.h>
18 #include <asm/memory.h>
19 #include "tcm.h"
21 static struct gen_pool *tcm_pool;
22 static bool dtcm_present;
23 static bool itcm_present;
25 /* TCM section definitions from the linker */
26 extern char __itcm_start, __sitcm_text, __eitcm_text;
27 extern char __dtcm_start, __sdtcm_data, __edtcm_data;
29 /* These will be increased as we run */
30 u32 dtcm_end = DTCM_OFFSET;
31 u32 itcm_end = ITCM_OFFSET;
34 * TCM memory resources
36 static struct resource dtcm_res = {
37 .name = "DTCM RAM",
38 .start = DTCM_OFFSET,
39 .end = DTCM_OFFSET,
40 .flags = IORESOURCE_MEM
43 static struct resource itcm_res = {
44 .name = "ITCM RAM",
45 .start = ITCM_OFFSET,
46 .end = ITCM_OFFSET,
47 .flags = IORESOURCE_MEM
50 static struct map_desc dtcm_iomap[] __initdata = {
52 .virtual = DTCM_OFFSET,
53 .pfn = __phys_to_pfn(DTCM_OFFSET),
54 .length = 0,
55 .type = MT_MEMORY_DTCM
59 static struct map_desc itcm_iomap[] __initdata = {
61 .virtual = ITCM_OFFSET,
62 .pfn = __phys_to_pfn(ITCM_OFFSET),
63 .length = 0,
64 .type = MT_MEMORY_ITCM
69 * Allocate a chunk of TCM memory
71 void *tcm_alloc(size_t len)
73 unsigned long vaddr;
75 if (!tcm_pool)
76 return NULL;
78 vaddr = gen_pool_alloc(tcm_pool, len);
79 if (!vaddr)
80 return NULL;
82 return (void *) vaddr;
84 EXPORT_SYMBOL(tcm_alloc);
87 * Free a chunk of TCM memory
89 void tcm_free(void *addr, size_t len)
91 gen_pool_free(tcm_pool, (unsigned long) addr, len);
93 EXPORT_SYMBOL(tcm_free);
95 bool tcm_dtcm_present(void)
97 return dtcm_present;
99 EXPORT_SYMBOL(tcm_dtcm_present);
101 bool tcm_itcm_present(void)
103 return itcm_present;
105 EXPORT_SYMBOL(tcm_itcm_present);
107 static int __init setup_tcm_bank(u8 type, u8 bank, u8 banks,
108 u32 *offset)
110 const int tcm_sizes[16] = { 0, -1, -1, 4, 8, 16, 32, 64, 128,
111 256, 512, 1024, -1, -1, -1, -1 };
112 u32 tcm_region;
113 int tcm_size;
116 * If there are more than one TCM bank of this type,
117 * select the TCM bank to operate on in the TCM selection
118 * register.
120 if (banks > 1)
121 asm("mcr p15, 0, %0, c9, c2, 0"
122 : /* No output operands */
123 : "r" (bank));
125 /* Read the special TCM region register c9, 0 */
126 if (!type)
127 asm("mrc p15, 0, %0, c9, c1, 0"
128 : "=r" (tcm_region));
129 else
130 asm("mrc p15, 0, %0, c9, c1, 1"
131 : "=r" (tcm_region));
133 tcm_size = tcm_sizes[(tcm_region >> 2) & 0x0f];
134 if (tcm_size < 0) {
135 pr_err("CPU: %sTCM%d of unknown size\n",
136 type ? "I" : "D", bank);
137 return -EINVAL;
138 } else if (tcm_size > 32) {
139 pr_err("CPU: %sTCM%d larger than 32k found\n",
140 type ? "I" : "D", bank);
141 return -EINVAL;
142 } else {
143 pr_info("CPU: found %sTCM%d %dk @ %08x, %senabled\n",
144 type ? "I" : "D",
145 bank,
146 tcm_size,
147 (tcm_region & 0xfffff000U),
148 (tcm_region & 1) ? "" : "not ");
151 /* Not much fun you can do with a size 0 bank */
152 if (tcm_size == 0)
153 return 0;
155 /* Force move the TCM bank to where we want it, enable */
156 tcm_region = *offset | (tcm_region & 0x00000ffeU) | 1;
158 if (!type)
159 asm("mcr p15, 0, %0, c9, c1, 0"
160 : /* No output operands */
161 : "r" (tcm_region));
162 else
163 asm("mcr p15, 0, %0, c9, c1, 1"
164 : /* No output operands */
165 : "r" (tcm_region));
167 /* Increase offset */
168 *offset += (tcm_size << 10);
170 pr_info("CPU: moved %sTCM%d %dk to %08x, enabled\n",
171 type ? "I" : "D",
172 bank,
173 tcm_size,
174 (tcm_region & 0xfffff000U));
175 return 0;
179 * This initializes the TCM memory
181 void __init tcm_init(void)
183 u32 tcm_status = read_cpuid_tcmstatus();
184 u8 dtcm_banks = (tcm_status >> 16) & 0x03;
185 u8 itcm_banks = (tcm_status & 0x03);
186 size_t dtcm_code_sz = &__edtcm_data - &__sdtcm_data;
187 size_t itcm_code_sz = &__eitcm_text - &__sitcm_text;
188 char *start;
189 char *end;
190 char *ram;
191 int ret;
192 int i;
194 /* Values greater than 2 for D/ITCM banks are "reserved" */
195 if (dtcm_banks > 2)
196 dtcm_banks = 0;
197 if (itcm_banks > 2)
198 itcm_banks = 0;
200 /* Setup DTCM if present */
201 if (dtcm_banks > 0) {
202 for (i = 0; i < dtcm_banks; i++) {
203 ret = setup_tcm_bank(0, i, dtcm_banks, &dtcm_end);
204 if (ret)
205 return;
207 /* This means you compiled more code than fits into DTCM */
208 if (dtcm_code_sz > (dtcm_end - DTCM_OFFSET)) {
209 pr_info("CPU DTCM: %u bytes of code compiled to "
210 "DTCM but only %lu bytes of DTCM present\n",
211 dtcm_code_sz, (dtcm_end - DTCM_OFFSET));
212 goto no_dtcm;
214 dtcm_res.end = dtcm_end - 1;
215 request_resource(&iomem_resource, &dtcm_res);
216 dtcm_iomap[0].length = dtcm_end - DTCM_OFFSET;
217 iotable_init(dtcm_iomap, 1);
218 /* Copy data from RAM to DTCM */
219 start = &__sdtcm_data;
220 end = &__edtcm_data;
221 ram = &__dtcm_start;
222 memcpy(start, ram, dtcm_code_sz);
223 pr_debug("CPU DTCM: copied data from %p - %p\n",
224 start, end);
225 dtcm_present = true;
226 } else if (dtcm_code_sz) {
227 pr_info("CPU DTCM: %u bytes of code compiled to DTCM but no "
228 "DTCM banks present in CPU\n", dtcm_code_sz);
231 no_dtcm:
232 /* Setup ITCM if present */
233 if (itcm_banks > 0) {
234 for (i = 0; i < itcm_banks; i++) {
235 ret = setup_tcm_bank(1, i, itcm_banks, &itcm_end);
236 if (ret)
237 return;
239 /* This means you compiled more code than fits into ITCM */
240 if (itcm_code_sz > (itcm_end - ITCM_OFFSET)) {
241 pr_info("CPU ITCM: %u bytes of code compiled to "
242 "ITCM but only %lu bytes of ITCM present\n",
243 itcm_code_sz, (itcm_end - ITCM_OFFSET));
244 return;
246 itcm_res.end = itcm_end - 1;
247 request_resource(&iomem_resource, &itcm_res);
248 itcm_iomap[0].length = itcm_end - ITCM_OFFSET;
249 iotable_init(itcm_iomap, 1);
250 /* Copy code from RAM to ITCM */
251 start = &__sitcm_text;
252 end = &__eitcm_text;
253 ram = &__itcm_start;
254 memcpy(start, ram, itcm_code_sz);
255 pr_debug("CPU ITCM: copied code from %p - %p\n",
256 start, end);
257 itcm_present = true;
258 } else if (itcm_code_sz) {
259 pr_info("CPU ITCM: %u bytes of code compiled to ITCM but no "
260 "ITCM banks present in CPU\n", itcm_code_sz);
265 * This creates the TCM memory pool and has to be done later,
266 * during the core_initicalls, since the allocator is not yet
267 * up and running when the first initialization runs.
269 static int __init setup_tcm_pool(void)
271 u32 dtcm_pool_start = (u32) &__edtcm_data;
272 u32 itcm_pool_start = (u32) &__eitcm_text;
273 int ret;
276 * Set up malloc pool, 2^2 = 4 bytes granularity since
277 * the TCM is sometimes just 4 KiB. NB: pages and cache
278 * line alignments does not matter in TCM!
280 tcm_pool = gen_pool_create(2, -1);
282 pr_debug("Setting up TCM memory pool\n");
284 /* Add the rest of DTCM to the TCM pool */
285 if (dtcm_present) {
286 if (dtcm_pool_start < dtcm_end) {
287 ret = gen_pool_add(tcm_pool, dtcm_pool_start,
288 dtcm_end - dtcm_pool_start, -1);
289 if (ret) {
290 pr_err("CPU DTCM: could not add DTCM " \
291 "remainder to pool!\n");
292 return ret;
294 pr_debug("CPU DTCM: Added %08x bytes @ %08x to " \
295 "the TCM memory pool\n",
296 dtcm_end - dtcm_pool_start,
297 dtcm_pool_start);
301 /* Add the rest of ITCM to the TCM pool */
302 if (itcm_present) {
303 if (itcm_pool_start < itcm_end) {
304 ret = gen_pool_add(tcm_pool, itcm_pool_start,
305 itcm_end - itcm_pool_start, -1);
306 if (ret) {
307 pr_err("CPU ITCM: could not add ITCM " \
308 "remainder to pool!\n");
309 return ret;
311 pr_debug("CPU ITCM: Added %08x bytes @ %08x to " \
312 "the TCM memory pool\n",
313 itcm_end - itcm_pool_start,
314 itcm_pool_start);
317 return 0;
320 core_initcall(setup_tcm_pool);