diff options
Diffstat (limited to 'os/hal/src/sdc.c')
| -rw-r--r-- | os/hal/src/sdc.c | 22 |
1 files changed, 12 insertions, 10 deletions
diff --git a/os/hal/src/sdc.c b/os/hal/src/sdc.c index 8e5546f87..11fcfa51a 100644 --- a/os/hal/src/sdc.c +++ b/os/hal/src/sdc.c @@ -303,24 +303,26 @@ static bool sdc_cmd6_check_status(sd_switch_function_t function, * @notapi
*/
static bool sdc_detect_bus_clk(SDCDriver *sdcp, sdcbusclk_t *clk) {
- uint32_t cmdarg = 0;
- uint8_t *scratchpad = sdcp->config->scratchpad;
+ uint32_t cmdarg;
+ const size_t N = 64;
+ uint8_t tmp[N];
/* Safe default.*/
*clk = SDC_CLK_25MHz;
- /* Use safe default when there is no space for data.*/
- if (NULL == scratchpad)
- return HAL_SUCCESS;
-
- if (sdc_lld_read_special(sdcp, scratchpad, 64, MMCSD_CMD_SWITCH, cmdarg))
+ /* Read switch functions' register.*/
+ if (sdc_lld_read_special(sdcp, tmp, N, MMCSD_CMD_SWITCH, 0))
return HAL_FAILED;
- if ((sdc_cmd6_extract_info(SD_SWITCH_FUNCTION_SPEED, scratchpad) & 2) == 2) {
+ /* Check card capabilities parsing acquired data.*/
+ if ((sdc_cmd6_extract_info(SD_SWITCH_FUNCTION_SPEED, tmp) & 2) == 2) {
+ /* Construct command to set the bus speed.*/
cmdarg = sdc_cmd6_construct(SD_SWITCH_SET, SD_SWITCH_FUNCTION_SPEED, 1);
- if (sdc_lld_read_special(sdcp, scratchpad, 64, MMCSD_CMD_SWITCH, cmdarg))
+ /* Write constructed command and read operation status in single call.*/
+ if (sdc_lld_read_special(sdcp, tmp, N, MMCSD_CMD_SWITCH, cmdarg))
return HAL_FAILED;
- if (HAL_SUCCESS == sdc_cmd6_check_status(SD_SWITCH_FUNCTION_SPEED, scratchpad))
+ /* Check card answer for success status bits.*/
+ if (HAL_SUCCESS == sdc_cmd6_check_status(SD_SWITCH_FUNCTION_SPEED, tmp))
*clk = SDC_CLK_50MHz;
}
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