fdt: Add APIs to read memory info from FDT
Implement `fdt_channel_count` and `fdt_get_channel_info` to obtain
memory information for FDT.
`fdt_channel_count` reports number of cahnnel utilized by the memory.
`fdt_get_channel_info` reports per channel memory information.
Including,
- LPDDR type
- Manufacturer ID
- Revision IDs
- IO width
- Total density per channel in megabits
- Total rank counts
BUG=b:348095503
TEST=USE="mosys_platform_arm -mosys_platform_geralt emerge-geralt mosys
Change-Id: I65f23a0280addb59394aaf4631b15422276ac3ab
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/mosys/+/5767005
Commit-Queue: Yidi Lin <yidilin@google.com>
Reviewed-by: Yu-Ping Wu <yupingso@chromium.org>
Reviewed-by: Jack Rosenthal <jrosenth@chromium.org>
Tested-by: Yidi Lin <yidilin@google.com>
diff --git a/include/lib/fdt.h b/include/lib/fdt.h
index 71c0ad0..95e23f9 100644
--- a/include/lib/fdt.h
+++ b/include/lib/fdt.h
@@ -54,4 +54,16 @@
extern int fdt_get_ram_ids(uint8_t *manufacturer_id, uint8_t *revision_id1,
uint8_t *revision_id2);
+struct fdt_memory_channel {
+ uint8_t lpddr_type;
+ uint8_t manufacturer_id;
+ uint8_t revision[2];
+ size_t io_width;
+ size_t density_mbits;
+ size_t num_ranks;
+};
+
+size_t fdt_channel_count(void);
+int fdt_get_channel_info(int channel, struct fdt_memory_channel *mem_info);
+
#endif /* MOSYS_LIB_FDT_H__ */
diff --git a/lib/file/fdt.c b/lib/file/fdt.c
index 45388d1..367dbdc 100644
--- a/lib/file/fdt.c
+++ b/lib/file/fdt.c
@@ -32,10 +32,13 @@
#include <arpa/inet.h>
#include <errno.h>
#include <inttypes.h>
+#include <limits.h>
#include <string.h>
+#include <unistd.h>
#include "lib/fdt.h"
#include "lib/file.h"
+#include "lib/nonspd.h"
#include "mosys/alloc.h"
#include "mosys/log.h"
@@ -53,7 +56,7 @@
/* Leave room for a null-terminator in the buffer */
char buf[sizeof(*val) + 1];
- if (read_file(path, buf, ARRAY_SIZE(buf), LOG_ERR) < 0)
+ if (read_file(path, buf, ARRAY_SIZE(buf), LOG_DEBUG) < 0)
return -1;
*val = ntohl(*(uint32_t *)buf);
@@ -76,12 +79,15 @@
return 0;
}
-int fdt_get_ram_ids(uint8_t *manufacturer_id, uint8_t *revision_id1,
- uint8_t *revision_id2)
+static int fdt_extract_info_from_compatible(const char *path,
+ uint8_t *lpddr_type,
+ uint8_t *manufacturer_id,
+ uint8_t *revision_id1,
+ uint8_t *revision_id2)
{
char buf[32];
- if (read_file(LPDDR3_COMPAT_PATH, buf, sizeof(buf), LOG_ERR) <= 0) {
+ if (read_file(path, buf, sizeof(buf), LOG_ERR) <= 0) {
lprintf(LOG_ERR, "%s: Error when reading Manufacturer ID\n",
__func__);
return -1;
@@ -91,16 +97,126 @@
* Manufacturer ID is in ascii value gated between '-' and ','
* characters. Revision ID is the hex number after the ','.
*/
- if (sscanf(buf, "lpddr%*1d-%2hhx,%2hhx%2hhx", manufacturer_id,
- revision_id1, revision_id2) != 3) {
+ if (sscanf(buf, "lpddr%1hhu-%2hhx,%2hhx%2hhx", lpddr_type,
+ manufacturer_id, revision_id1, revision_id2) != 4) {
lprintf(LOG_ERR,
- "%s: Error when parsing Manufacturer/Revision ID\n",
+ "%s: Error when parsing LPDDR type/Manufacturer/Revision ID\n",
__func__);
return -1;
}
lprintf(LOG_DEBUG,
- "%s: manufacturer_id: %#02x, revision_id: %#02x %#02x\n",
- __func__, *manufacturer_id, *revision_id1, *revision_id2);
+ "%s: lpddr_type: %u, manufacturer_id: %#02x, revision_id: %#02x %#02x\n",
+ __func__, *lpddr_type, *manufacturer_id, *revision_id1,
+ *revision_id2);
+ return 0;
+}
+
+int fdt_get_ram_ids(uint8_t *manufacturer_id, uint8_t *revision_id1,
+ uint8_t *revision_id2)
+{
+ uint8_t lpddr_type;
+
+ return fdt_extract_info_from_compatible(LPDDR3_COMPAT_PATH, &lpddr_type,
+ manufacturer_id, revision_id1,
+ revision_id2);
+}
+
+size_t fdt_channel_count(void)
+{
+ int status = 0;
+ size_t channel_count = 0;
+ char filepath[PATH_MAX];
+
+ while (status == 0) {
+ snprintf(filepath, sizeof(filepath),
+ "/proc/device-tree/lpddr-channel%zu/name",
+ channel_count);
+ status = access(filepath, F_OK);
+
+ if (status == 0)
+ channel_count++;
+ }
+
+ return channel_count;
+}
+
+int fdt_get_channel_info(int channel, struct fdt_memory_channel *chan_info)
+{
+ int status = 0, rank_count = 0;
+ char filepath[PATH_MAX], channel_path[PATH_MAX];
+ uint8_t lpddr_type, mfg_id, rev_id1, rev_id2;
+ uint32_t rank_size, channel_io_width, rank_io_width, density;
+
+ if (!chan_info)
+ return -1;
+
+ snprintf(channel_path, sizeof(channel_path),
+ "/proc/device-tree/lpddr-channel%d", channel);
+
+ /* Get channel-io-width */
+ snprintf(filepath, sizeof(filepath), "%s/io-width", channel_path);
+ if (fdt_get_uint32_val(filepath, &channel_io_width)) {
+ lprintf(LOG_ERR, "%s: Error when reading channel-io-width\n",
+ __func__);
+ return -1;
+ }
+
+ /* Get rank-io-width */
+ snprintf(filepath, sizeof(filepath), "%s/rank@%d/io-width",
+ channel_path, rank_count);
+ if (fdt_get_uint32_val(filepath, &rank_io_width)) {
+ lprintf(LOG_ERR, "%s: Error when reading rank-io-width\n",
+ __func__);
+ return -1;
+ }
+
+ if (rank_io_width == 0 || channel_io_width % rank_io_width) {
+ lprintf(LOG_ERR,
+ "%s: channel_io_width is not a multiple of "
+ "rank_io_width\n",
+ __func__);
+ return -1;
+ }
+
+ /* Calculate rank_count and density */
+ density = 0;
+ while (status == 0) {
+ snprintf(filepath, sizeof(filepath), "%s/rank@%d/density",
+ channel_path, rank_count);
+ status = fdt_get_uint32_val(filepath, &rank_size);
+
+ if (status == 0) {
+ density +=
+ rank_size * (channel_io_width / rank_io_width);
+ rank_count++;
+ }
+ }
+
+ if (rank_count == 0) {
+ lprintf(LOG_ERR, "%s: Error when reading rank size\n",
+ __func__);
+ return -1;
+ }
+
+ /* Get LPDDR type, manufacturer ID, revision IDs */
+ snprintf(filepath, sizeof(filepath), "%s/rank@0/compatible",
+ channel_path);
+ if (fdt_extract_info_from_compatible(filepath, &lpddr_type, &mfg_id,
+ &rev_id1, &rev_id2)) {
+ lprintf(LOG_ERR,
+ "%s: Error when reading info from compatible\n",
+ __func__);
+ return -1;
+ }
+
+ chan_info->lpddr_type = lpddr_type;
+ chan_info->manufacturer_id = mfg_id;
+ chan_info->revision[0] = rev_id1;
+ chan_info->revision[1] = rev_id2;
+ chan_info->io_width = rank_io_width;
+ chan_info->density_mbits = density;
+ chan_info->num_ranks = rank_count;
+
return 0;
}
