esp-idf/components/driver/sdmmc_host.c

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// Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include <stdbool.h>
#include <stddef.h>
#include <sys/param.h>
#include "esp_log.h"
#include "esp_intr_alloc.h"
#include "soc/sdmmc_struct.h"
#include "soc/sdmmc_reg.h"
#include "soc/io_mux_reg.h"
#include "soc/gpio_sig_map.h"
#include "rom/gpio.h"
#include "driver/gpio.h"
#include "driver/sdmmc_host.h"
#include "sdmmc_private.h"
#define SDMMC_EVENT_QUEUE_LENGTH 32
typedef struct {
uint32_t clk;
uint32_t cmd;
uint32_t d0;
uint32_t d1;
uint32_t d2;
uint32_t d3;
uint32_t d4;
uint32_t d5;
uint32_t d6;
uint32_t d7;
uint8_t card_detect;
uint8_t write_protect;
uint8_t width;
} sdmmc_slot_info_t;
static void sdmmc_isr(void* arg);
static void sdmmc_host_dma_init();
static const sdmmc_slot_info_t s_slot_info[2] = {
{
.clk = PERIPHS_IO_MUX_SD_CLK_U,
.cmd = PERIPHS_IO_MUX_SD_CMD_U,
.d0 = PERIPHS_IO_MUX_SD_DATA0_U,
.d1 = PERIPHS_IO_MUX_SD_DATA1_U,
.d2 = PERIPHS_IO_MUX_SD_DATA2_U,
.d3 = PERIPHS_IO_MUX_SD_DATA3_U,
.d4 = PERIPHS_IO_MUX_GPIO16_U,
.d5 = PERIPHS_IO_MUX_GPIO17_U,
.d6 = PERIPHS_IO_MUX_GPIO5_U,
.d7 = PERIPHS_IO_MUX_GPIO18_U,
.card_detect = HOST_CARD_DETECT_N_1_IDX,
.write_protect = HOST_CARD_WRITE_PRT_1_IDX,
.width = 8
},
{
.clk = PERIPHS_IO_MUX_MTMS_U,
.cmd = PERIPHS_IO_MUX_MTDO_U,
.d0 = PERIPHS_IO_MUX_GPIO2_U,
.d1 = PERIPHS_IO_MUX_GPIO4_U,
.d2 = PERIPHS_IO_MUX_MTDI_U,
.d3 = PERIPHS_IO_MUX_MTCK_U,
.card_detect = HOST_CARD_DETECT_N_2_IDX,
.write_protect = HOST_CARD_WRITE_PRT_2_IDX,
.width = 4
}
};
static const char* TAG = "sdmmc_periph";
static intr_handle_t s_intr_handle;
static QueueHandle_t s_event_queue;
void sdmmc_host_reset()
{
// Set reset bits
SDMMC.ctrl.controller_reset = 1;
SDMMC.ctrl.dma_reset = 1;
SDMMC.ctrl.fifo_reset = 1;
// Wait for the reset bits to be cleared by hardware
while (SDMMC.ctrl.controller_reset || SDMMC.ctrl.fifo_reset || SDMMC.ctrl.dma_reset) {
;
}
}
/* We have two clock divider stages:
* - one is the clock generator which drives SDMMC peripheral,
* it can be configured using SDMMC.clock register. It can generate
* frequencies 160MHz/(N + 1), where 0 < N < 16, I.e. from 10 to 80 MHz.
* - 4 clock dividers inside SDMMC peripheral, which can divide clock
* from the first stage by 2 * M, where 0 < M < 255
* (they can also be bypassed).
*
* For cards which aren't UHS-1 or UHS-2 cards, which we don't support,
* maximum bus frequency in high speed (HS) mode is 50 MHz.
* Note: for non-UHS-1 cards, HS mode is optional.
* Default speed (DS) mode is mandatory, it works up to 25 MHz.
* Whether the card supports HS or not can be determined using TRAN_SPEED
* field of card's CSD register.
*
* 50 MHz can not be obtained exactly, closest we can get is 53 MHz.
* For now set the first stage divider to generate 40MHz, and then configure
* the second stage dividers to generate the frequency requested.
*
* Of the second stage dividers, div0 is used for card 0, and div1 is used
* for card 1.
*/
static void sdmmc_host_input_clk_enable()
{
// Set frequency to 160MHz / (p + 1) = 40MHz, duty cycle (h + 1)/(p + 1) = 1/2
SDMMC.clock.div_factor_p = 3;
SDMMC.clock.div_factor_h = 1;
SDMMC.clock.div_factor_m = 3;
// Set phases for in/out clocks
SDMMC.clock.phase_dout = 4;
SDMMC.clock.phase_din = 4;
SDMMC.clock.phase_core = 0;
// Wait for the clock to propagate
ets_delay_us(10);
}
static void sdmmc_host_input_clk_disable()
{
SDMMC.clock.val = 0;
}
static void sdmmc_host_clock_update_command(int slot)
{
// Clock update command (not a real command; just updates CIU registers)
sdmmc_hw_cmd_t cmd_val = {
.card_num = slot,
.update_clk_reg = 1,
.wait_complete = 1
};
bool repeat = true;
while(repeat) {
sdmmc_host_start_command(slot, cmd_val, 0);
while (true) {
// Sending clock update command to the CIU can generate HLE error.
// According to the manual, this is okay and we must retry the command.
if (SDMMC.rintsts.hle) {
SDMMC.rintsts.hle = 1;
repeat = true;
break;
}
// When the command is accepted by CIU, start_command bit will be
// cleared in SDMMC.cmd register.
if (SDMMC.cmd.start_command == 0) {
repeat = false;
break;
}
}
}
}
esp_err_t sdmmc_host_set_card_clk(int slot, uint32_t freq_khz)
{
if (!(slot == 0 || slot == 1)) {
return ESP_ERR_INVALID_ARG;
}
const int clk40m = 40000;
// Disable clock first
SDMMC.clkena.cclk_enable &= ~BIT(slot);
sdmmc_host_clock_update_command(slot);
// Calculate new dividers
int div = 0;
if (freq_khz < clk40m) {
// round up; extra *2 is because clock divider divides by 2*n
div = (clk40m + freq_khz * 2 - 1) / (freq_khz * 2);
}
ESP_LOGD(TAG, "slot=%d div=%d freq=%dkHz", slot, div,
(div == 0) ? clk40m : clk40m / (2 * div));
// Program CLKDIV and CLKSRC, send them to the CIU
switch(slot) {
case 0:
SDMMC.clksrc.card0 = 0;
SDMMC.clkdiv.div0 = div;
break;
case 1:
SDMMC.clksrc.card1 = 1;
SDMMC.clkdiv.div1 = div;
break;
}
sdmmc_host_clock_update_command(slot);
// Re-enable clocks
SDMMC.clkena.cclk_enable |= BIT(slot);
SDMMC.clkena.cclk_low_power |= BIT(slot);
sdmmc_host_clock_update_command(slot);
// set data timeout
const uint32_t data_timeout_ms = 100;
uint32_t data_timeout_cycles = data_timeout_ms * freq_khz;
const uint32_t data_timeout_cycles_max = 0xffffff;
if (data_timeout_cycles > data_timeout_cycles_max) {
data_timeout_cycles = data_timeout_cycles_max;
}
SDMMC.tmout.data = data_timeout_cycles;
// always set response timeout to highest value, it's small enough anyway
SDMMC.tmout.response = 255;
return ESP_OK;
}
esp_err_t sdmmc_host_start_command(int slot, sdmmc_hw_cmd_t cmd, uint32_t arg) {
if (!(slot == 0 || slot == 1)) {
return ESP_ERR_INVALID_ARG;
}
while (SDMMC.cmd.start_command == 1) {
;
}
SDMMC.cmdarg = arg;
cmd.card_num = slot;
cmd.start_command = 1;
SDMMC.cmd = cmd;
return ESP_OK;
}
esp_err_t sdmmc_host_init()
{
if (s_intr_handle) {
return ESP_ERR_INVALID_STATE;
}
// Enable clock to peripheral
sdmmc_host_input_clk_enable();
// Reset
sdmmc_host_reset();
ESP_LOGD(TAG, "peripheral version %x, hardware config %08x", SDMMC.verid, SDMMC.hcon);
// Clear interrupt status and set interrupt mask to known state
SDMMC.rintsts.val = 0xffffffff;
SDMMC.intmask.val = 0;
SDMMC.ctrl.int_enable = 0;
// Allocate event queue
s_event_queue = xQueueCreate(SDMMC_EVENT_QUEUE_LENGTH, sizeof(sdmmc_event_t));
if (!s_event_queue) {
return ESP_ERR_NO_MEM;
}
// Attach interrupt handler
esp_err_t ret = esp_intr_alloc(ETS_SDIO_HOST_INTR_SOURCE, 0, &sdmmc_isr, s_event_queue, &s_intr_handle);
if (ret != ESP_OK) {
vQueueDelete(s_event_queue);
s_event_queue = NULL;
return ret;
}
// Enable interrupts
SDMMC.intmask.val =
SDMMC_INTMASK_CD |
SDMMC_INTMASK_CMD_DONE |
SDMMC_INTMASK_DATA_OVER |
SDMMC_INTMASK_RCRC | SDMMC_INTMASK_DCRC |
SDMMC_INTMASK_RTO | SDMMC_INTMASK_DTO | SDMMC_INTMASK_HTO |
SDMMC_INTMASK_SBE | SDMMC_INTMASK_EBE |
SDMMC_INTMASK_RESP_ERR | SDMMC_INTMASK_HLE;
SDMMC.ctrl.int_enable = 1;
// Enable DMA
sdmmc_host_dma_init();
// Initialize transaction handler
ret = sdmmc_host_transaction_handler_init();
if (ret != ESP_OK) {
vQueueDelete(s_event_queue);
s_event_queue = NULL;
esp_intr_free(s_intr_handle);
s_intr_handle = NULL;
return ret;
}
return ESP_OK;
}
static inline void configure_pin(uint32_t io_mux_reg)
{
const int sdmmc_func = 3;
const int drive_strength = 3;
PIN_INPUT_ENABLE(io_mux_reg);
PIN_FUNC_SELECT(io_mux_reg, sdmmc_func);
PIN_SET_DRV(io_mux_reg, drive_strength);
}
esp_err_t sdmmc_host_init_slot(int slot, const sdmmc_slot_config_t* slot_config)
{
if (!s_intr_handle) {
return ESP_ERR_INVALID_STATE;
}
if (!(slot == 0 || slot == 1)) {
return ESP_ERR_INVALID_ARG;
}
if (slot_config == NULL) {
return ESP_ERR_INVALID_ARG;
}
int gpio_cd = slot_config->gpio_cd;
int gpio_wp = slot_config->gpio_wp;
uint8_t slot_width = slot_config->width;
// Configure pins
const sdmmc_slot_info_t* pslot = &s_slot_info[slot];
if (slot_width == SDMMC_SLOT_WIDTH_DEFAULT) {
slot_width = pslot->width;
}
else if (slot_width > pslot->width) {
return ESP_ERR_INVALID_ARG;
}
configure_pin(pslot->clk);
configure_pin(pslot->cmd);
configure_pin(pslot->d0);
if (slot_width >= 4) {
configure_pin(pslot->d1);
configure_pin(pslot->d2);
configure_pin(pslot->d3);
if (slot_width == 8) {
configure_pin(pslot->d4);
configure_pin(pslot->d5);
configure_pin(pslot->d6);
configure_pin(pslot->d7);
}
}
if (gpio_cd != -1) {
gpio_set_direction(gpio_cd, GPIO_MODE_INPUT);
gpio_matrix_in(gpio_cd, pslot->card_detect, 0);
}
if (gpio_wp != -1) {
gpio_set_direction(gpio_wp, GPIO_MODE_INPUT);
gpio_matrix_in(gpio_wp, pslot->write_protect, 0);
}
// By default, set probing frequency (400kHz) and 1-bit bus
esp_err_t ret = sdmmc_host_set_card_clk(slot, 400);
if (ret != ESP_OK) {
return ret;
}
ret = sdmmc_host_set_bus_width(slot, 1);
if (ret != ESP_OK) {
return ret;
}
return ESP_OK;
}
esp_err_t sdmmc_host_deinit()
{
if (!s_intr_handle) {
return ESP_ERR_INVALID_STATE;
}
esp_intr_free(s_intr_handle);
s_intr_handle = NULL;
vQueueDelete(s_event_queue);
s_event_queue = NULL;
sdmmc_host_input_clk_disable();
sdmmc_host_transaction_handler_deinit();
return ESP_OK;
}
esp_err_t sdmmc_host_wait_for_event(int tick_count, sdmmc_event_t* out_event)
{
if (!out_event) {
return ESP_ERR_INVALID_ARG;
}
if (!s_event_queue) {
return ESP_ERR_INVALID_STATE;
}
int ret = xQueueReceive(s_event_queue, out_event, tick_count);
if (ret == pdFALSE) {
return ESP_ERR_TIMEOUT;
}
return ESP_OK;
}
esp_err_t sdmmc_host_set_bus_width(int slot, size_t width)
{
if (!(slot == 0 || slot == 1)) {
return ESP_ERR_INVALID_ARG;
}
if (s_slot_info[slot].width < width) {
return ESP_ERR_INVALID_ARG;
}
const uint16_t mask = BIT(slot);
if (width == 1) {
SDMMC.ctype.card_width_8 &= ~mask;
SDMMC.ctype.card_width &= ~mask;
} else if (width == 4) {
SDMMC.ctype.card_width_8 &= ~mask;
SDMMC.ctype.card_width |= mask;
} else if (width == 8){
SDMMC.ctype.card_width_8 |= mask;
} else {
return ESP_ERR_INVALID_ARG;
}
ESP_LOGD(TAG, "slot=%d width=%d", slot, width);
return ESP_OK;
}
static void sdmmc_host_dma_init()
{
SDMMC.ctrl.dma_enable = 1;
SDMMC.bmod.val = 0;
SDMMC.bmod.sw_reset = 1;
SDMMC.idinten.ni = 1;
SDMMC.idinten.ri = 1;
SDMMC.idinten.ti = 1;
}
void sdmmc_host_dma_stop()
{
SDMMC.ctrl.use_internal_dma = 0;
SDMMC.ctrl.dma_reset = 1;
SDMMC.bmod.fb = 0;
SDMMC.bmod.enable = 0;
}
void sdmmc_host_dma_prepare(sdmmc_desc_t* desc, size_t block_size, size_t data_size)
{
// Set size of data and DMA descriptor pointer
SDMMC.bytcnt = data_size;
SDMMC.blksiz = block_size;
SDMMC.dbaddr = desc;
// Enable everything needed to use DMA
SDMMC.ctrl.dma_enable = 1;
SDMMC.ctrl.use_internal_dma = 1;
SDMMC.bmod.enable = 1;
SDMMC.bmod.fb = 1;
sdmmc_host_dma_resume();
}
void sdmmc_host_dma_resume()
{
SDMMC.pldmnd = 1;
}
/**
* @brief SDMMC interrupt handler
*
* Ignoring SDIO and streaming read/writes for now (and considering just SD memory cards),
* all communication is driven by the master, and the hardware handles things like stop
* commands automatically. So the interrupt handler doesn't need to do much, we just push
* interrupt status into a queue, clear interrupt flags, and let the task currently doing
* communication figure out what to do next.
*
* Card detect interrupts pose a small issue though, because if a card is plugged in and
* out a few times, while there is no task to process the events, event queue can become
* full and some card detect events may be dropped. We ignore this problem for now, since
* the there are no other interesting events which can get lost due to this.
*/
static void sdmmc_isr(void* arg) {
QueueHandle_t queue = (QueueHandle_t) arg;
sdmmc_event_t event;
uint32_t pending = SDMMC.mintsts.val;
SDMMC.rintsts.val = pending;
event.sdmmc_status = pending;
uint32_t dma_pending = SDMMC.idsts.val;
SDMMC.idsts.val = dma_pending;
event.dma_status = dma_pending & 0x1f;
int higher_priority_task_awoken = pdFALSE;
xQueueSendFromISR(queue, &event, &higher_priority_task_awoken);
if (higher_priority_task_awoken == pdTRUE) {
portYIELD_FROM_ISR();
}
}