[PATCH] Backport of development SPI SD-card patches to RTEMS 4.10.
Pavel Pisa
ppisa4lists at pikron.com
Tue Oct 8 08:43:40 UTC 2013
From: Pavel Pisa <ppisa at pikron.com>
Arnout Vandecappelle:
PR 1569/misc
* libchip/i2c/spi-sd-card.c: Added CRC checks.
PR 1576/misc
* libchip/i2c/spi-sd-card.c: Enable CRC checks.
PR 1567/misc
* libchip/i2c/spi-sd-card.h, libchip/i2c/spi-sd-card.c: Fixed
timeouts.
PR 1579/misc
* libchip/i2c/spi-sd-card.c: Gradually increasing sleep times when
waiting for write to finish.
PR 1580/misc
* libchip/i2c/spi-sd-card.c: Use bigger chunks and yield processor
while waiting for read data.
PR 1586/misc
* libchip/i2c/spi-sd-card.h, libchip/i2c/spi-sd-card.c: Add retries to
SD card accesses.
Signed-off-by: Pavel Pisa <ppisa at pikron.com>
---
c/src/libchip/i2c/spi-sd-card.c | 214 +++++++++++++++++++++++++++++++--------
c/src/libchip/i2c/spi-sd-card.h | 9 +-
2 files changed, 176 insertions(+), 47 deletions(-)
diff --git a/c/src/libchip/i2c/spi-sd-card.c b/c/src/libchip/i2c/spi-sd-card.c
index 71d307d..5a30451 100644
--- a/c/src/libchip/i2c/spi-sd-card.c
+++ b/c/src/libchip/i2c/spi-sd-card.c
@@ -12,11 +12,13 @@
* Germany
* rtems at embedded-brains.de
*
- * The license and distribution terms for this file may be found in the file
- * LICENSE in this distribution or at http://www.rtems.com/license/LICENSE.
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.com/license/LICENSE.
*/
#include <stdio.h>
+#include <string.h>
#include <errno.h>
#include <inttypes.h>
@@ -301,9 +303,55 @@ static inline uint32_t sd_card_access_time( const uint8_t *csd)
static inline uint32_t sd_card_max_access_time( const uint8_t *csd, uint32_t transfer_speed)
{
uint64_t ac = sd_card_access_time( csd);
+ uint32_t ac_100ms = transfer_speed / 80;
uint32_t n = SD_CARD_CSD_GET_NSAC( csd) * 100;
- ac = (ac * transfer_speed) / 8000000000ULL;
- return n + (uint32_t) ac;
+ /* ac is in ns, transfer_speed in bps, max_access_time in bytes.
+ max_access_time is 100 times typical access time (taac+nsac) */
+ ac = ac * transfer_speed / 80000000;
+ ac = ac + 100*n;
+ if ((uint32_t)ac > ac_100ms)
+ return ac_100ms;
+ else
+ return (uint32_t)ac;
+}
+
+/** @} */
+
+/**
+ * @name CRC functions
+ *
+ * Based on http://en.wikipedia.org/wiki/Computation_of_CRC
+ *
+ * @{
+ */
+
+static uint8_t sd_card_compute_crc7 (uint8_t *data, size_t len)
+{
+ uint8_t e, f, crc;
+ size_t i;
+
+ crc = 0;
+ for (i = 0; i < len; i++) {
+ e = crc ^ data[i];
+ f = e ^ (e >> 4) ^ (e >> 7);
+ crc = (f << 1) ^ (f << 4);
+ }
+ return crc >> 1;
+}
+
+static uint16_t sd_card_compute_crc16 (uint8_t *data, size_t len)
+{
+ uint8_t s, t;
+ uint16_t crc;
+ size_t i;
+
+ crc = 0;
+ for (i = 0; i < len; i++) {
+ s = data[i] ^ (crc >> 8);
+ t = s ^ (s >> 4);
+ crc = (crc << 8) ^ t ^ (t << 5) ^ (t << 12);
+ }
+ return crc;
}
/** @} */
@@ -323,6 +371,14 @@ static int sd_card_wait( sd_card_driver_entry *e)
int rv = 0;
int r = 0;
int n = 2;
+ /* For writes, the timeout is 2.5 times that of reads; since we
+ don't know if it is a write or read, assume write.
+ FIXME should actually look at R2W_FACTOR for non-HC cards. */
+ int retries = e->n_ac_max * 25 / 10;
+ /* n_ac_max/100 is supposed to be the average waiting time. To
+ approximate this, we start with waiting n_ac_max/150 and
+ gradually increase the waiting time. */
+ int wait_time_bytes = (retries + 149) / 150;
while (e->busy) {
/* Query busy tokens */
rv = sd_card_query( e, e->response, n);
@@ -335,11 +391,20 @@ static int sd_card_wait( sd_card_driver_entry *e)
return 0;
}
}
- n = SD_CARD_COMMAND_SIZE;
+ retries -= n;
+ if (retries <= 0) {
+ return -RTEMS_TIMEOUT;
+ }
if (e->schedule_if_busy) {
- /* Invoke the scheduler */
- rtems_task_wake_after( RTEMS_YIELD_PROCESSOR);
+ uint64_t wait_time_us = wait_time_bytes;
+ wait_time_us *= 8000000;
+ wait_time_us /= e->transfer_mode.baudrate;
+ rtems_task_wake_after( RTEMS_MICROSECONDS_TO_TICKS(wait_time_us));
+ retries -= wait_time_bytes;
+ wait_time_bytes = wait_time_bytes * 15 / 10;
+ } else {
+ n = SD_CARD_COMMAND_SIZE;
}
}
return 0;
@@ -354,6 +419,7 @@ static int sd_card_send_command( sd_card_driver_entry *e, uint32_t command, uint
.byte_cnt = SD_CARD_COMMAND_SIZE
};
int r = 0;
+ uint8_t crc7;
SD_CARD_INVALIDATE_RESPONSE_INDEX( e);
@@ -364,6 +430,8 @@ static int sd_card_send_command( sd_card_driver_entry *e, uint32_t command, uint
/* Write command and read response */
SD_CARD_COMMAND_SET_COMMAND( e->command, command);
SD_CARD_COMMAND_SET_ARGUMENT( e->command, argument);
+ crc7 = sd_card_compute_crc7( e->command + 1, 5);
+ SD_CARD_COMMAND_SET_CRC7( e->command, crc7);
rv = rtems_libi2c_ioctl( e->bus, RTEMS_LIBI2C_IOCTL_READ_WRITE, &rw);
RTEMS_CHECK_RV( rv, "Write command and read response");
@@ -404,6 +472,7 @@ sd_card_send_command_error:
static int sd_card_send_register_command( sd_card_driver_entry *e, uint32_t command, uint32_t argument, uint32_t *reg)
{
int rv = 0;
+ uint8_t crc7;
rv = sd_card_send_command( e, command, argument);
RTEMS_CHECK_RV( rv, "Send command");
@@ -417,6 +486,13 @@ static int sd_card_send_register_command( sd_card_driver_entry *e, uint32_t comm
return -RTEMS_IO_ERROR;
}
+ crc7 = sd_card_compute_crc7( e->response + e->response_index, 5);
+ if (crc7 != SD_CARD_COMMAND_GET_CRC7( e->response + e->response_index) &&
+ SD_CARD_COMMAND_GET_CRC7( e->response + e->response_index) != 0x7f) {
+ RTEMS_SYSLOG_ERROR( "CRC check failed on register command\n");
+ return -RTEMS_IO_ERROR;
+ }
+
*reg = sd_card_get_uint32( e->response + e->response_index + 1);
return 0;
@@ -456,54 +532,65 @@ static int sd_card_read( sd_card_driver_entry *e, uint8_t start_token, uint8_t *
{
int rv = 0;
- /* Access time idle tokens */
- uint32_t n_ac = 1;
-
/* Discard command response */
int r = e->response_index + 1;
- /* Minimum token number before data start */
- int next_response_size = 2;
-
/* Standard response size */
int response_size = SD_CARD_COMMAND_SIZE;
+ /* Where the response is stored */
+ uint8_t *response = e->response;
+
/* Data input index */
int i = 0;
+ /* CRC check of data */
+ uint16_t crc16;
+
+ /* Maximum number of tokens to read. */
+ int retries = e->n_ac_max;
+
SD_CARD_INVALIDATE_RESPONSE_INDEX( e);
while (true) {
RTEMS_DEBUG_PRINT( "Search from %u to %u\n", r, response_size - 1);
/* Search the data start token in in current response buffer */
+ retries -= (response_size - r);
while (r < response_size) {
- RTEMS_DEBUG_PRINT( "Token [%02u]: 0x%02x\n", r, e->response [r]);
- if (n_ac > e->n_ac_max) {
- RTEMS_SYSLOG_ERROR( "Timeout\n");
- return -RTEMS_IO_ERROR;
- } else if (e->response [r] == start_token) {
+ RTEMS_DEBUG_PRINT( "Token [%02u]: 0x%02x\n", r, response [r]);
+ if (response [r] == start_token) {
/* Discard data start token */
++r;
goto sd_card_read_start;
- } else if (SD_CARD_IS_DATA_ERROR( e->response [r])) {
- RTEMS_SYSLOG_ERROR( "Data error token [%02i]: 0x%02" PRIx8 "\n", r, e->response [r]);
+ } else if (SD_CARD_IS_DATA_ERROR( response [r])) {
+ RTEMS_SYSLOG_ERROR( "Data error token [%02i]: 0x%02" PRIx8 "\n", r, response [r]);
return -RTEMS_IO_ERROR;
- } else if (e->response [r] != SD_CARD_IDLE_TOKEN) {
- RTEMS_SYSLOG_ERROR( "Unexpected token [%02i]: 0x%02" PRIx8 "\n", r, e->response [r]);
+ } else if (response [r] != SD_CARD_IDLE_TOKEN) {
+ RTEMS_SYSLOG_ERROR( "Unexpected token [%02i]: 0x%02" PRIx8 "\n", r, response [r]);
return -RTEMS_IO_ERROR;
}
- ++n_ac;
++r;
}
- /* Query more */
- rv = sd_card_query( e, e->response, next_response_size);
- RTEMS_CHECK_RV( rv, "Query data start token");
+ if (retries <= 0) {
+ RTEMS_SYSLOG_ERROR( "Timeout\n");
+ return -RTEMS_IO_ERROR;
+ }
+
+ if (e->schedule_if_busy)
+ rtems_task_wake_after( RTEMS_YIELD_PROCESSOR);
- /* Set standard query size */
- response_size = next_response_size;
- next_response_size = SD_CARD_COMMAND_SIZE;
+ /* Query more. We typically have to wait between 10 and 100
+ bytes. To reduce overhead, read the response in chunks of
+ 50 bytes - this doesn't introduce too much copy overhead
+ but does allow SPI DMA transfers to work efficiently. */
+ response = in;
+ response_size = 50;
+ if (response_size > n)
+ response_size = n;
+ rv = sd_card_query( e, response, response_size);
+ RTEMS_CHECK_RV( rv, "Query data start token");
/* Reset start position */
r = 0;
@@ -513,7 +600,7 @@ sd_card_read_start:
/* Read data */
while (r < response_size && i < n) {
- in [i++] = e->response [r++];
+ in [i++] = response [r++];
}
/* Read more data? */
@@ -527,13 +614,21 @@ sd_card_read_start:
rv = sd_card_query( e, e->response, 3);
RTEMS_CHECK_RV( rv, "Read CRC 16");
+ crc16 = sd_card_compute_crc16 (in, n);
+ if ((e->response[0] != ((crc16 >> 8) & 0xff)) ||
+ (e->response[1] != (crc16 & 0xff))) {
+ RTEMS_SYSLOG_ERROR( "CRC check failed on read\n");
+ return -RTEMS_IO_ERROR;
+ }
+
return i;
}
static int sd_card_write( sd_card_driver_entry *e, uint8_t start_token, uint8_t *out, int n)
{
int rv = 0;
- uint8_t crc16 [2] = { 0, 0 };
+ uint8_t crc16_bytes [2] = { 0, 0 };
+ uint16_t crc16;
/* Data output index */
int o = 0;
@@ -551,7 +646,10 @@ static int sd_card_write( sd_card_driver_entry *e, uint8_t start_token, uint8_t
RTEMS_CHECK_RV( o, "Write data");
/* Write CRC 16 */
- rv = rtems_libi2c_write_bytes( e->bus, crc16, 2);
+ crc16 = sd_card_compute_crc16(out, n);
+ crc16_bytes[0] = (crc16>>8) & 0xff;
+ crc16_bytes[1] = (crc16) & 0xff;
+ rv = rtems_libi2c_write_bytes( e->bus, crc16_bytes, 2);
RTEMS_CHECK_RV( rv, "Write CRC 16");
/* Read data response */
@@ -605,6 +703,7 @@ static rtems_status_code sd_card_init( sd_card_driver_entry *e)
uint32_t write_block_size = 0;
uint8_t csd_structure = 0;
uint64_t capacity = 0;
+ uint8_t crc7;
/* Assume first that we have a SD card and not a MMC card */
bool assume_sd = true;
@@ -671,12 +770,8 @@ static rtems_status_code sd_card_init( sd_card_driver_entry *e)
* getting the High Capacity Support flag HCS and checks that the
* voltage is right. Some MMCs accept this command but will still fail
* on ACMD41. SD 1.x cards will fails this command and do not support
- * HCS (> 2G capacity). SD spec requires the correct CRC7 be sent even
- * when in SPI mode. So this will just change the default CRC7 and
- * keep it there for all subsequent commands (which just require a do
- * not care CRC byte).
+ * HCS (> 2G capacity).
*/
- SD_CARD_COMMAND_SET_CRC7( e->command, 0x43U);
rv = sd_card_send_register_command( e, SD_CARD_CMD_SEND_IF_COND, if_cond_reg, &if_cond_reg);
/*
@@ -692,6 +787,9 @@ static rtems_status_code sd_card_init( sd_card_driver_entry *e)
cmd_arg = SD_CARD_FLAG_HCS;
}
+ /* Enable CRC */
+ sd_card_send_command( e, SD_CARD_CMD_CRC_ON_OFF, 1);
+
/* Initialize card */
while (true) {
if (assume_sd) {
@@ -840,6 +938,9 @@ static rtems_status_code sd_card_init( sd_card_driver_entry *e)
RTEMS_SYSLOG( "Product serial number : %" PRIu32 "\n", SD_CARD_CID_GET_PSN( block));
RTEMS_SYSLOG( "Manufacturing date : %" PRIu8 "\n", SD_CARD_CID_GET_MDT( block));
RTEMS_SYSLOG( "7-bit CRC checksum : %" PRIu8 "\n", SD_CARD_CID_GET_CRC7( block));
+ crc7 = sd_card_compute_crc7( block, 15);
+ if (crc7 != SD_CARD_CID_GET_CRC7( block))
+ RTEMS_SYSLOG( " Failed! (computed %02" PRIx8 ")\n", crc7);
}
/* Card Specific Data */
@@ -850,6 +951,13 @@ static rtems_status_code sd_card_init( sd_card_driver_entry *e)
rv = sd_card_read( e, SD_CARD_START_BLOCK_SINGLE_BLOCK_READ, block, SD_CARD_CSD_SIZE);
RTEMS_CLEANUP_RV_SC( rv, sc, sd_card_driver_init_cleanup, "Read: SD_CARD_CMD_SEND_CSD");
+ crc7 = sd_card_compute_crc7( block, 15);
+ if (crc7 != SD_CARD_CID_GET_CRC7( block)) {
+ RTEMS_SYSLOG( "SD_CARD_CMD_SEND_CSD CRC failed\n");
+ sc = RTEMS_IO_ERROR;
+ goto sd_card_driver_init_cleanup;
+ }
+
/* CSD Structure */
csd_structure = SD_CARD_CSD_GET_CSD_STRUCTURE( block);
@@ -883,6 +991,9 @@ static rtems_status_code sd_card_init( sd_card_driver_entry *e)
capacity = (c_size + 1) * 512 * 1024;
read_block_size = 512;
write_block_size = 512;
+
+ /* Timeout is fixed at 100ms in CSD Version 2.0 */
+ e->n_ac_max = transfer_speed / 80;
} else {
RTEMS_DO_CLEANUP_SC( RTEMS_IO_ERROR, sc, sd_card_driver_init_cleanup, "Unexpected CSD Structure number");
}
@@ -893,6 +1004,7 @@ static rtems_status_code sd_card_init( sd_card_driver_entry *e)
RTEMS_SYSLOG( "CSD structure : %" PRIu8 "\n", SD_CARD_CSD_GET_CSD_STRUCTURE( block));
RTEMS_SYSLOG( "Spec version : %" PRIu8 "\n", SD_CARD_CSD_GET_SPEC_VERS( block));
RTEMS_SYSLOG( "Access time [ns] : %" PRIu32 "\n", sd_card_access_time( block));
+ RTEMS_SYSLOG( "Access time [N] : %" PRIu32 "\n", SD_CARD_CSD_GET_NSAC( block)*100);
RTEMS_SYSLOG( "Max access time [N] : %" PRIu32 "\n", e->n_ac_max);
RTEMS_SYSLOG( "Max read block size [B] : %" PRIu32 "\n", read_block_size);
RTEMS_SYSLOG( "Max write block size [B] : %" PRIu32 "\n", write_block_size);
@@ -1023,7 +1135,7 @@ sd_card_disk_block_read_cleanup:
/* Done */
r->req_done( r->done_arg, RTEMS_IO_ERROR);
- return rv;
+ return 0;
}
static int sd_card_disk_block_write( sd_card_driver_entry *e, rtems_blkdev_request *r)
@@ -1116,7 +1228,7 @@ sd_card_disk_block_write_cleanup:
/* Done */
r->req_done( r->done_arg, RTEMS_IO_ERROR);
- return rv;
+ return 0;
}
static int sd_card_disk_ioctl( rtems_disk_device *dd, uint32_t req, void *arg)
@@ -1126,20 +1238,31 @@ static int sd_card_disk_ioctl( rtems_disk_device *dd, uint32_t req, void *arg)
rtems_device_minor_number minor = rtems_disk_get_minor_number( dd);
sd_card_driver_entry *e = &sd_card_driver_table [minor];
rtems_blkdev_request *r = (rtems_blkdev_request *) arg;
+ int (*f)( sd_card_driver_entry *, rtems_blkdev_request *);
+ uint32_t retries = e->retries;
+ int result;
+
switch (r->req) {
case RTEMS_BLKDEV_REQ_READ:
- return sd_card_disk_block_read( e, r);
+ f = sd_card_disk_block_read;
+ break;
case RTEMS_BLKDEV_REQ_WRITE:
- return sd_card_disk_block_write( e, r);
+ f = sd_card_disk_block_write;
+ break;
default:
- errno = EINVAL;
+ errno = EINVAL;
return -1;
}
+ do {
+ result = f( e, r);
+ } while (retries-- > 0 && result != 0);
+ return result;
+
} else if (req == RTEMS_BLKIO_CAPABILITIES) {
*(uint32_t *) arg = RTEMS_BLKDEV_CAP_MULTISECTOR_CONT;
return 0;
} else {
- errno = EINVAL;
+ errno = EINVAL;
return -1;
}
}
@@ -1155,9 +1278,12 @@ static rtems_status_code sd_card_disk_init( rtems_device_major_number major, rte
for (minor = 0; minor < sd_card_driver_table_size; ++minor) {
sd_card_driver_entry *e = &sd_card_driver_table [minor];
dev_t dev = rtems_filesystem_make_dev_t( major, minor);
+ uint32_t retries = e->retries;
/* Initialize SD Card */
- sc = sd_card_init( e);
+ do {
+ sc = sd_card_init( e);
+ } while (retries-- > 0 && sc != RTEMS_SUCCESSFUL);
RTEMS_CHECK_SC( sc, "Initialize SD Card");
/* Create disk device */
diff --git a/c/src/libchip/i2c/spi-sd-card.h b/c/src/libchip/i2c/spi-sd-card.h
index 9817381..6c4f95c 100644
--- a/c/src/libchip/i2c/spi-sd-card.h
+++ b/c/src/libchip/i2c/spi-sd-card.h
@@ -12,8 +12,9 @@
* Germany
* rtems at embedded-brains.de
*
- * The license and distribution terms for this file may be found in the file
- * LICENSE in this distribution or at http://www.rtems.com/license/LICENSE.
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.com/license/LICENSE.
*/
#ifndef LIBI2C_SD_CARD_H
@@ -52,7 +53,8 @@ extern "C" {
SD_CARD_IDLE_TOKEN \
}
-#define SD_CARD_N_AC_MAX_DEFAULT 8
+/* Default speed = 400kbps, default timeout = 100ms, n_ac_max is in bytes */
+#define SD_CARD_N_AC_MAX_DEFAULT 5000
typedef struct {
const char *device_name;
@@ -68,6 +70,7 @@ typedef struct {
bool busy;
bool verbose;
bool schedule_if_busy;
+ uint32_t retries;
} sd_card_driver_entry;
extern sd_card_driver_entry sd_card_driver_table [];
--
1.7.10.4
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