/**
* Fusée SD/MMC driver for the Switch
* ~ktemkin
*/
#include <string.h>
#include <stdint.h>
#include <errno.h>
#include "lib/driver_utils.h"
#include "sdmmc.h"
#include "car.h"
#include "pinmux.h"
#include "timers.h"
#include "apb_misc.h"
#include "gpio.h"
#include "supplies.h"
#include "pmc.h"
#include "pad_control.h"
#define TEGRA_SDMMC_BASE (0x700B0000)
#define TEGRA_SDMMC_SIZE (0x200)
/**
* Map of tegra SDMMC registers
*/
struct PACKED tegra_sdmmc {
/* SDHCI standard registers */
uint32_t dma_address;
uint16_t block_size;
uint16_t block_count;
uint32_t argument;
uint16_t transfer_mode;
uint16_t command;
uint32_t response[0x4];
uint32_t buffer;
uint32_t present_state;
uint8_t host_control;
uint8_t power_control;
uint8_t block_gap_control;
uint8_t wake_up_control;
uint16_t clock_control;
uint8_t timeout_control;
uint8_t software_reset;
uint32_t int_status;
uint32_t int_enable;
uint32_t signal_enable;
uint16_t acmd12_err;
uint16_t host_control2;
uint32_t capabilities;
uint32_t capabilities_1;
uint32_t max_current;
uint32_t _0x4c;
uint16_t set_acmd12_error;
uint16_t set_int_error;
uint16_t adma_error;
uint8_t _0x55[0x3];
uint32_t adma_address;
uint32_t upper_adma_address;
uint16_t preset_for_init;
uint16_t preset_for_default;
uint16_t preset_for_high;
uint16_t preset_for_sdr12;
uint16_t preset_for_sdr25;
uint16_t preset_for_sdr50;
uint16_t preset_for_sdr104;
uint16_t preset_for_ddr50;
uint8_t _0x70[0x3];
uint32_t _0x74[0x22];
uint16_t slot_int_status;
uint16_t host_version;
/* vendor specific registers */
uint32_t vendor_clock_cntrl;
uint32_t vendor_sys_sw_cntrl;
uint32_t vendor_err_intr_status;
uint32_t vendor_cap_overrides;
uint32_t vendor_boot_cntrl;
uint32_t vendor_boot_ack_timeout;
uint32_t vendor_boot_dat_timeout;
uint32_t vendor_debounce_count;
uint32_t vendor_misc_cntrl;
uint32_t max_current_override;
uint32_t max_current_override_hi;
uint32_t _0x12c[0x21];
uint32_t vendor_io_trim_cntrl;
/* start of sdmmc2/sdmmc4 only */
uint32_t vendor_dllcal_cfg;
uint32_t vendor_dll_ctrl0;
uint32_t vendor_dll_ctrl1;
uint32_t vendor_dllcal_cfg_sta;
/* end of sdmmc2/sdmmc4 only */
uint32_t vendor_tuning_cntrl0;
uint32_t vendor_tuning_cntrl1;
uint32_t vendor_tuning_status0;
uint32_t vendor_tuning_status1;
uint32_t vendor_clk_gate_hysteresis_count;
uint32_t vendor_preset_val0;
uint32_t vendor_preset_val1;
uint32_t vendor_preset_val2;
uint32_t sdmemcomppadctrl;
uint32_t auto_cal_config;
uint32_t auto_cal_interval;
uint32_t auto_cal_status;
uint32_t io_spare;
uint32_t sdmmca_mccif_fifoctrl;
uint32_t timeout_wcoal_sdmmca;
uint32_t _0x1fc;
};
/**
* SDMMC response lengths
*/
enum sdmmc_response_type {
MMC_RESPONSE_NONE = 0,
MMC_RESPONSE_LEN136 = 1,
MMC_RESPONSE_LEN48 = 2,
MMC_RESPONSE_LEN48_CHK_BUSY = 3,
};
/**
* Lengths of SD command responses
*/
enum sdmmc_response_sizes {
/* Bytes in a LEN136 response */
MMC_RESPONSE_SIZE_LEN136 = 15,
};
/**
* SDMMC response sanity checks
* see the standard for when these should be used
*/
enum sdmmc_response_checks {
MMC_CHECKS_NONE = 0,
MMC_CHECKS_CRC = (1 << 3),
MMC_CHECKS_INDEX = (1 << 4),
MMC_CHECKS_ALL = (1 << 4) | (1 << 3),
};
/**
* General masks for SDMMC registers.
*/
enum sdmmc_register_bits {
/* Present state register */
MMC_COMMAND_INHIBIT = (1 << 0),
MMC_DATA_INHIBIT = (1 << 1),
MMC_BUFFER_WRITE_ENABLE = (1 << 10),
MMC_BUFFER_READ_ENABLE = (1 << 11),
MMC_DAT0_LINE_STATE = (1 << 20),
/* Block size register */
MMC_DMA_BOUNDARY_MAXIMUM = (0x3 << 12),
MMC_DMA_BOUNDARY_512K = (0x3 << 12),
MMC_DMA_BOUNDARY_16K = (0x2 << 12),
MMC_TRANSFER_BLOCK_512B = (0x200 << 0),
/* Command register */
MMC_COMMAND_NUMBER_SHIFT = 8,
MMC_COMMAND_RESPONSE_TYPE_SHIFT = 0,
MMC_COMMAND_HAS_DATA = 1 << 5,
MMC_COMMAND_TYPE_ABORT = 3 << 6,
MMC_COMMAND_CHECK_NUMBER = 1 << 4,
/* Transfer mode arguments */
MMC_TRANSFER_DMA_ENABLE = (1 << 0),
MMC_TRANSFER_LIMIT_BLOCK_COUNT = (1 << 1),
MMC_TRANSFER_MULTIPLE_BLOCKS = (1 << 5),
MMC_TRANSFER_AUTO_CMD_MASK = (0x3 << 2),
MMC_TRANSFER_AUTO_CMD = (0x3 << 2),
MMC_TRANSFER_AUTO_CMD12 = (0x1 << 2),
MMC_TRANSFER_CARD_TO_HOST = (1 << 4),
/* Interrupt status */
MMC_STATUS_COMMAND_COMPLETE = (1 << 0),
MMC_STATUS_TRANSFER_COMPLETE = (1 << 1),
MMC_STATUS_DMA_INTERRUPT = (1 << 3),
MMC_STATUS_COMMAND_TIMEOUT = (1 << 16),
MMC_STATUS_COMMAND_CRC_ERROR = (1 << 17),
MMC_STATUS_COMMAND_END_BIT_ERROR = (1 << 18),
MMC_STATUS_COMMAND_INDEX_ERROR = (1 << 19),
MMC_STATUS_ERROR_MASK = (0xF << 16),
/* Host control */
MMC_DMA_SELECT_MASK = (0x3 << 3),
MMC_DMA_SELECT_SDMA = (0x0 << 3),
MMC_HOST_BUS_WIDTH_MASK = (1 << 1) | (1 << 5),
MMC_HOST_BUS_WIDTH_4BIT = (1 << 1),
MMC_HOST_BUS_WIDTH_8BIT = (1 << 5),
/* Software reset */
MMC_SOFT_RESET_FULL = (1 << 0),
/* Vendor clock control */
MMC_CLOCK_TAP_MASK = (0xFF << 16),
MMC_CLOCK_TAP_SDMMC1 = (0x04 << 16),
MMC_CLOCK_TAP_SDMMC4 = (0x00 << 16),
MMC_CLOCK_TRIM_MASK = (0xFF << 24),
MMC_CLOCK_TRIM_SDMMC1 = (0x02 << 24),
MMC_CLOCK_TRIM_SDMMC4 = (0x08 << 24),
/* Auto cal configuration */
MMC_AUTOCAL_PDPU_CONFIG_MASK = 0x7f7f,
MMC_AUTOCAL_PDPU_SDMMC1_1V8 = 0x7b7b,
MMC_AUTOCAL_PDPU_SDMMC1_3V3 = 0x7d00,
MMC_AUTOCAL_PDPU_SDMMC4_1V8 = 0x0505,
};
/**
* SDMMC commands
*/
enum sdmmc_command {
CMD_GO_IDLE_OR_INIT = 0,
CMD_SEND_OPERATING_CONDITIONS = 1,
CMD_ALL_SEND_CID = 2,
CMD_SET_RELATIVE_ADDR = 3,
CMD_GET_RELATIVE_ADDR = 3,
CMD_SET_DSR = 4,
CMD_TOGGLE_SLEEP_AWAKE = 5,
CMD_SWITCH_MODE = 6,
CMD_TOGGLE_CARD_SELECT = 7,
CMD_SEND_EXT_CSD = 8,
CMD_SEND_IF_COND = 8,
CMD_SEND_CSD = 9,
CMD_SEND_CID = 10,
CMD_STOP_TRANSMISSION = 12,
CMD_READ_STATUS = 13,
CMD_BUS_TEST = 14,
CMD_GO_INACTIVE = 15,
CMD_SET_BLKLEN = 16,
CMD_READ_SINGLE_BLOCK = 17,
CMD_READ_MULTIPLE_BLOCK = 18,
CMD_WRITE_SINGLE_BLOCK = 24,
CMD_WRITE_MULTIPLE_BLOCK = 25,
CMD_APP_SEND_OP_COND = 41,
CMD_APP_COMMAND = 55,
};
/**
* String descriptions of each command.
*/
static const char *sdmmc_command_string[] = {
"CMD_GO_IDLE_OR_INIT",
"CMD_SEND_OPERATING_CONDITIONS",
"CMD_ALL_SEND_CID",
"CMD_SET_RELATIVE_ADDR",
"CMD_SET_DSR",
"CMD_TOGGLE_SLEEP_AWAKE",
"CMD_SWITCH_MODE",
"CMD_TOGGLE_CARD_SELECT",
"CMD_SEND_EXT_CSD/CMD_SEND_IF_COND",
"CMD_SEND_CSD",
"CMD_SEND_CID ",
"<unsupported>",
"CMD_STOP_TRANSMISSION",
"CMD_READ_STATUS",
"CMD_BUS_TEST",
"CMD_GO_INACTIVE",
"CMD_SET_BLKLEN",
"CMD_READ_SINGLE_BLOCK",
"CMD_READ_MULTIPLE_BLOCK",
};
/**
* SDMMC command argument numbers
*/
enum sdmmc_command_magic {
MMC_ENABLE_BOOT_INIT_MAGIC = 0xf0f0f0f0,
MMC_ENABLE_BOOT_ENABLE_MAGIC = 0xfffffffa,
MMC_EMMC_OPERATING_COND_CAPACITY_MAGIC = 0x00ff8080,
MMC_EMMC_OPERATING_COND_CAPACITY_MASK = 0x0fffffff,
MMC_EMMC_OPERATING_COND_BUSY = (0x04 << 28),
MMC_EMMC_OPERATING_COND_READY = (0x0c << 28),
MMC_EMMC_OPERATING_READINESS_MASK = (0x0f << 28),
MMC_SD_OPERATING_COND_READY = (1 << 31),
MMC_SD_OPERATING_COND_HIGH_CAPACITY = (1 << 30),
MMC_SD_OPERATING_COND_ACCEPTS_3V3 = (1 << 20),
/* READ_STATUS responses */
MMC_STATUS_MASK = (0xf << 9),
MMC_STATUS_PROGRAMMING = (0x7 << 9),
MMC_STATUS_READY_FOR_DATA = (0x1 << 8),
MMC_STATUS_CHECK_ERROR = (~0x0206BF7F),
/* IF_COND components */
MMC_IF_VOLTAGE_3V3 = (1 << 8),
MMC_IF_CHECK_PATTERN = 0xAA,
};
/**
* Version magic numbers for different CSD versions.
*/
enum sdmmc_csd_versions {
MMC_CSD_VERSION1 = 0,
MMC_CSD_VERSION2 = 1,
};
/**
* Positions of different fields in various CSDs.
* May eventually be replaced with a bitfield struct, if we use enough of the CSDs.
*/
enum sdmmc_csd_extents {
/* csd structure version */
MMC_CSD_STRUCTURE_START = 126,
MMC_CSD_STRUCTURE_WIDTH = 2,
/* read block length */
MMC_CSD_V1_READ_BL_LENGTH_START = 80,
MMC_CSD_V1_READ_BL_LENGTH_WIDTH = 4,
};
/**
* Positions of the different fields in the Extended CSD.
*/
enum sdmmc_ext_csd_extents {
MMC_EXT_CSD_SIZE = 512,
/* Hardware partition registers */
MMC_EXT_CSD_PARTITION_SETTING_COMPLETE = 155,
MMC_EXT_CSD_PARTITION_SETTING_COMPLETED = (1 << 0),
MMC_EXT_CSD_PARTITION_ATTRIBUTE = 156,
MMC_EXT_CSD_PARTITION_ENHANCED_ATTRIBUTE = 0x1f,
MMC_EXT_CSD_PARTITION_SUPPORT = 160,
MMC_SUPPORTS_HARDWARE_PARTS = (1 << 0),
MMC_EXT_CSD_ERASE_GROUP_DEF = 175,
MMC_EXT_CSD_ERASE_GROUP_DEF_BIT = (1 << 0),
MMC_EXT_CSD_PARTITION_CONFIG = 179,
MMC_EXT_CSD_PARTITION_SELECT_MASK = 0x7,
MMC_EXT_CSD_PARTITION_SWITCH_TIME = 199,
MMC_EXT_CSD_PARTITION_SWITCH_SCALE_US = 10000,
};
/* SDMMC debug enable */
static int sdmmc_loglevel = 0;
/**
* Page-aligned bounce buffer to target with SDMMC DMA.
* If the size of this buffer is changed, the block_size
*/
static uint8_t ALIGN(4096) sdmmc_bounce_buffer[4096 * 4];
static const uint16_t sdmmc_bounce_dma_boundary = MMC_DMA_BOUNDARY_16K;
/**
* Sets the current SDMMC debugging loglevel.
*
* @param loglevel Current log level. A higher value prints more logs.
*/
void sdmmc_set_loglevel(int loglevel)
{
sdmmc_loglevel = loglevel;
}
/**
* Internal utility function for generating debug prints at various log levels.
*/
static void mmc_vprint(struct mmc *mmc, char *fmt, int required_loglevel, va_list list)
{
// Allow debug prints to be silenced by a negative loglevel.
if (sdmmc_loglevel < required_loglevel)
return;
printk("%s: ", mmc->name);
vprintk(fmt, list);
printk("\n");
}
/**
* Normal SDMMC print for SDMMC information.
*/
static void mmc_print(struct mmc *mmc, char *fmt, ...)
{
va_list list;
va_start(list, fmt);
mmc_vprint(mmc, fmt, 0, list);
va_end(list);
}
/**
* Normal SDMMC print for SDMMC information.
*/
static void mmc_debug(struct mmc *mmc, char *fmt, ...)
{
va_list list;
va_start(list, fmt);
mmc_vprint(mmc, fmt, 1, list);
va_end(list);
}
/**
* @return a statically allocated string that describes the given command
*/
static const char *sdmmc_get_command_string(enum sdmmc_command command)
{
switch (command) {
// Commands that aren't in the lower block.
case CMD_APP_COMMAND:
return "CMD_APP_COMMAND";
case CMD_APP_SEND_OP_COND:
return "CMD_APP_SEND_OP_COND";
case CMD_WRITE_SINGLE_BLOCK:
return "CMD_WRITE_SINGLE_BLOCK";
case CMD_WRITE_MULTIPLE_BLOCK:
return "CMD_WRITE_MULTIPLE_BLOCK";
// For commands with low numbers, read them string from the relevant array.
default:
return sdmmc_command_string[command];
}
}
/**
* Debug: print out any errors that occurred during a command timeout
*/
void mmc_print_command_errors(struct mmc *mmc, int command_errno)
{
if (command_errno & MMC_STATUS_COMMAND_TIMEOUT)
mmc_print(mmc, "ERROR: command timed out!");
if (command_errno & MMC_STATUS_COMMAND_CRC_ERROR)
mmc_print(mmc, "ERROR: command response had invalid CRC");
if (command_errno & MMC_STATUS_COMMAND_END_BIT_ERROR)
mmc_print(mmc, "ERROR: command response had invalid end bit");
if (command_errno & MMC_STATUS_COMMAND_INDEX_ERROR)
mmc_print(mmc, "ERROR: response appears not to be for the last issued command");
}
/**
* Retreives the SDMMC register range for the given controller.
*/
static struct tegra_sdmmc *sdmmc_get_regs(enum sdmmc_controller controller)
{
// Start with the base addresss of the SDMMC_BLOCK
uintptr_t addr = TEGRA_SDMMC_BASE;
// Offset our address by the controller number.
addr += (controller * TEGRA_SDMMC_SIZE);
// Return the controller.
return (struct tegra_sdmmc *)addr;
}
/**
* Performs a soft-reset of the SDMMC controller.
*
* @param mmc The MMC controller to be reset.
* @return 0 if the device successfully came out of reset; or an error code otherwise
*/
static int sdmmc_hardware_reset(struct mmc *mmc)
{
uint32_t timebase = get_time();
// Reset the MMC controller...
mmc->regs->software_reset |= MMC_SOFT_RESET_FULL;
// Wait for the SDMMC controller to come back up...
while (mmc->regs->software_reset & MMC_SOFT_RESET_FULL) {
if (get_time_since(timebase) > mmc->timeout) {
mmc_print(mmc, "failed to bring up SDMMC controller");
return ETIMEDOUT;
}
}
return 0;
}
/**
* Performs low-level initialization for SDMMC4, used for the eMMC.
*/
static int sdmmc4_set_up_clock_and_io(struct mmc *mmc)
{
volatile struct tegra_car *car = car_get_regs();
volatile struct tegra_padctl *padctl = padctl_get_regs();
(void)mmc;
// Put SDMMC4 in reset
car->rst_dev_l_set |= 0x8000;
// Set SDMMC4 clock source (PLLP_OUT0) and divisor (32).
// We use 32 beacuse Nintendo does, and they probably know what they're doing?
car->clk_src[CLK_SOURCE_SDMMC4] = CLK_SOURCE_FIRST | CLK_DIVIDER_32;
// Set the legacy divier used for detecting timeouts.
car->clk_src_y[CLK_SOURCE_SDMMC_LEGACY] = CLK_SOURCE_FIRST | CLK_DIVIDER_32;
// Set SDMMC4 clock enable
car->clk_enb_l_set |= 0x8000;
car->clk_enb_y_set |= CAR_CONTROL_SDMMC_LEGACY;
// host_clk_delay(0x64, clk_freq) -> Delay 100 host clock cycles
udelay(5000);
// Take SDMMC4 out of reset
car->rst_dev_l_clr |= 0x8000;
// Enable input paths for all pins.
padctl->sdmmc2_control |=
PADCTL_SDMMC4_ENABLE_DATA_IN | PADCTL_SDMMC4_ENABLE_CLK_IN | PADCTL_SDMMC4_DEEP_LOOPBACK;
return 0;
}
/**
* Enables power supplies for SDMMC4, used for eMMC.
*/
static int sdmmc4_enable_supplies(struct mmc *mmc)
{
// As a booot device, SDMMC4's power supply is always on.
return 0;
}
/**
* Enables power supplies for SDMMC1, used for the SD card slot.
*/
static int sdmmc1_enable_supplies(struct mmc *mmc)
{
volatile struct tegra_pmc *pmc = pmc_get_regs();
volatile struct tegra_pinmux *pinmux = pinmux_get_regs();
// Set PAD_E_INPUT_OR_E_PWRD (relevant for eMMC only)
mmc->regs->sdmemcomppadctrl |= 0x80000000;
// Ensure the PMC is prepared for the SDMMC card to recieve power.
pmc->no_iopower &= ~PMC_CONTROL_SDMMC1;
pmc->pwr_det_val |= PMC_CONTROL_SDMMC1;
// Configure the enable line for the SD card power.
pinmux->dmic3_clk = PINMUX_SELECT_FUNCTION0;
gpio_configure_mode(GPIO_MICROSD_SUPPLY_ENABLE, GPIO_MODE_GPIO);
gpio_configure_direction(GPIO_MICROSD_SUPPLY_ENABLE, GPIO_DIRECTION_OUTPUT);
gpio_write(GPIO_MICROSD_SUPPLY_ENABLE, GPIO_LEVEL_HIGH);
return 0;
}
/**
* Performs low-level initialization for SDMMC1, used for the SD card slot.
*/
static int sdmmc1_set_up_clock_and_io(struct mmc *mmc)
{
volatile struct tegra_car *car = car_get_regs();
volatile struct tegra_pinmux *pinmux = pinmux_get_regs();
volatile struct tegra_padctl *padctl = padctl_get_regs();
(void)mmc;
// Set up each of the relevant pins to be connected to output drivers,
// and selected for SDMMC use.
pinmux->sdmmc1_clk = PINMUX_DRIVE_2X | PINMUX_PARKED | PINMUX_SELECT_FUNCTION0 | PINMUX_INPUT;
pinmux->sdmmc1_cmd = PINMUX_DRIVE_2X | PINMUX_PARKED | PINMUX_SELECT_FUNCTION0 | PINMUX_INPUT | PINMUX_PULL_UP;
pinmux->sdmmc1_dat3 = PINMUX_DRIVE_2X | PINMUX_PARKED | PINMUX_SELECT_FUNCTION0 | PINMUX_INPUT | PINMUX_PULL_UP;
pinmux->sdmmc1_dat2 = PINMUX_DRIVE_2X | PINMUX_PARKED | PINMUX_SELECT_FUNCTION0 | PINMUX_INPUT | PINMUX_PULL_UP;
pinmux->sdmmc1_dat1 = PINMUX_DRIVE_2X | PINMUX_PARKED | PINMUX_SELECT_FUNCTION0 | PINMUX_INPUT | PINMUX_PULL_UP;
pinmux->sdmmc1_dat0 = PINMUX_DRIVE_2X | PINMUX_PARKED | PINMUX_SELECT_FUNCTION0 | PINMUX_INPUT | PINMUX_PULL_UP;
// Set up the card detect pin as a GPIO input.
pinmux->pz1 = PINMUX_TRISTATE | PINMUX_SELECT_FUNCTION1 | PINMUX_PULL_UP | PINMUX_INPUT;
gpio_configure_mode(GPIO_MICROSD_CARD_DETECT, GPIO_MODE_GPIO);
gpio_configure_direction(GPIO_MICROSD_CARD_DETECT, GPIO_DIRECTION_INPUT);
udelay(100);
// Ensure we're using GPIO and not GPIO for the SD card's card detect.
padctl->vgpio_gpio_mux_sel &= ~PADCTL_SDMMC1_CD_SOURCE;
// Put SDMMC1 in reset
car->rst_dev_l_set |= CAR_CONTROL_SDMMC1;
// Set SDMMC1 clock source (PLLP_OUT0) and divisor (32).
// We use 32 beacuse Nintendo does, and they probably know what they're doing?
car->clk_src[CLK_SOURCE_SDMMC1] = CLK_SOURCE_FIRST | CLK_DIVIDER_32;
// Set the legacy divier used for detecting timeouts.
car->clk_src_y[CLK_SOURCE_SDMMC_LEGACY] = CLK_SOURCE_FIRST | CLK_DIVIDER_32;
// Set SDMMC1 clock enable
car->clk_enb_l_set |= CAR_CONTROL_SDMMC1;
car->clk_enb_y_set |= CAR_CONTROL_SDMMC_LEGACY;
// Set up SD card voltages.
udelay(1000);
supply_enable(SUPPLY_MICROSD);
udelay(1000);
// host_clk_delay(0x64, clk_freq) -> Delay 100 host clock cycles
udelay(5000);
// Take SDMMC4 out of reset
car->rst_dev_l_clr |= CAR_CONTROL_SDMMC1;
// Enable clock loopback.
padctl->sdmmc1_control |= PADCTL_SDMMC1_DEEP_LOOPBACK;
return 0;
}
/**
* Configures clocking parameters for a given controller.
*
* @param mmc The MMC controller to set up.
*/
static int sdmmc_set_up_clocking_parameters(struct mmc *mmc)
{
// TODO: decide if these should be split into separate functions after seeing how much
// is common to the tunable modes
// TODO: timing for HS400/HS667 modes
// TODO: timing for tuanble modes (SDR50/104/200)
// Clear the I/O conditioning constants.
mmc->regs->vendor_clock_cntrl &= ~(MMC_CLOCK_TRIM_MASK | MMC_CLOCK_TAP_MASK);
mmc->regs->auto_cal_config &= ~MMC_AUTOCAL_PDPU_CONFIG_MASK;
// Set up the I/O conditioning constants used to ensure we have a reliable clock.
// Constants above and procedure below from the TRM.
switch (mmc->controller) {
case SWITCH_EMMC:
mmc->regs->vendor_clock_cntrl |= (MMC_CLOCK_TRIM_SDMMC4 | MMC_CLOCK_TAP_SDMMC4);
mmc->regs->auto_cal_config |= MMC_AUTOCAL_PDPU_SDMMC4_1V8;
break;
case SWITCH_MICROSD:
mmc->regs->vendor_clock_cntrl |= (MMC_CLOCK_TRIM_SDMMC1 | MMC_CLOCK_TAP_SDMMC1);
mmc->regs->auto_cal_config |= MMC_AUTOCAL_PDPU_SDMMC1_3V3;
break;
default:
printk("ERROR: initialization not yet writen for SDMMC%d", mmc->controller);
return ENODEV;
}
return 0;
}
/**
* Initialize the low-level SDMMC hardware.
* Thanks to hexkyz for this init code.
*
* FIXME: clean up the magic numbers, split into sections.
*/
static int sdmmc_hardware_init(struct mmc *mmc)
{
volatile struct tegra_sdmmc *regs = mmc->regs;
uint32_t timebase;
bool is_timeout;
int rc;
// Initialize the Tegra resources necessary to use the given piece of hardware.
rc = mmc->set_up_clock_and_io(mmc);
if (rc) {
mmc_print(mmc, "ERROR: could not set up controller for use!");
return rc;
}
// Software reset the SDMMC device
rc = sdmmc_hardware_reset(mmc);
if (rc) {
mmc_print(mmc, "failed to reset!");
return rc;
}
// Turn on the card's power supplies...
rc = mmc->enable_supplies(mmc);
if (rc) {
mmc_print(mmc, "ERROR: could power on the card!");
return rc;
}
// Set IO_SPARE[19] (one cycle delay)
regs->io_spare |= 0x80000;
// Clear SEL_VREG
regs->vendor_io_trim_cntrl &= ~(0x04);
// Set SDMMC2TMC_CFG_SDMEMCOMP_VREF_SEL to 0x07
regs->sdmemcomppadctrl &= ~(0x0F);
regs->sdmemcomppadctrl |= 0x07;
// Set auto-calibration PD/PU offsets
/*
*/
// Set ourselves up to have a stable.
rc = sdmmc_set_up_clocking_parameters(mmc);
if (rc) {
mmc_print(mmc, "WARNING: could not optimize card clocking parameters. (%d)", rc);
}
// Set PAD_E_INPUT_OR_E_PWRD (relevant for eMMC only)
regs->sdmemcomppadctrl |= 0x80000000;
// Wait one milisecond
udelay(1000);
// Set AUTO_CAL_START and AUTO_CAL_ENABLE
regs->auto_cal_config |= 0xA0000000;
udelay(1000);
// Program a timeout of 10ms
is_timeout = false;
timebase = get_time();
// Wait for AUTO_CAL_ACTIVE to be cleared
while ((regs->auto_cal_status & 0x80000000) && !is_timeout) {
// Keep checking if timeout expired
is_timeout = get_time_since(timebase) > 10000;
}
// AUTO_CAL_ACTIVE was not cleared in time
if (is_timeout) {
mmc_print(mmc, "autocal failed!");
return ETIMEDOUT;
}
// Clear PAD_E_INPUT_OR_E_PWRD (relevant for eMMC only)
regs->sdmemcomppadctrl &= ~(0x80000000);
// Set SDHCI_CLOCK_INT_EN
regs->clock_control |= 0x01;
// Program a timeout of 2000ms
timebase = get_time();
is_timeout = false;
// Wait for SDHCI_CLOCK_INT_STABLE to be set
while (!(regs->clock_control & 0x02) && !is_timeout) {
// Keep checking if timeout expired
is_timeout = get_time_since(timebase) > 2000000;
}
// Clock failed to stabilize
if (is_timeout) {
mmc_print(mmc, "clock never stabalized!");
return -1;
}
// FIXME: replace this to support better clocks
regs->host_control2 = 0;
// Clear SDHCI_PROG_CLOCK_MODE
regs->clock_control &= ~(0x20);
// Clear SDHCI_CTRL_SDMA and SDHCI_CTRL_ADMA2
regs->host_control &= 0xE7;
// Set the timeout to be the maximum value
regs->timeout_control &= ~(0x0F);
regs->timeout_control |= 0x0E;
// Clear SDHCI_CTRL_4BITBUS and SDHCI_CTRL_8BITBUS
regs->host_control &= 0xFD;
regs->host_control &= 0xDF;
// Set up the SD card's voltage.
regs->power_control &= 0xF1;
regs->power_control |= mmc->operating_voltage << 1;
// Mark the power as on.
regs->power_control |= 0x01;
// Clear TAP_VAL_UPDATED_BY_HW
regs->vendor_tuning_cntrl0 &= ~(0x20000);
// Clear SDHCI_CTRL_HISPD
regs->host_control &= 0xFB;
// Clear SDHCI_CTRL_VDD_180
regs->host_control2 &= ~(0x08);
// Set SDHCI_DIVIDER and SDHCI_DIVIDER_HI
// FIXME: divider SD if necessary
regs->clock_control &= ~(0xFFC0);
regs->clock_control |= (0x30 << 8); // 200kHz, initially
// Set SDHCI_CLOCK_CARD_EN
regs->clock_control |= 0x04;
// Ensure we're using Single-operation DMA (SDMA) mode for DMA.
regs->host_control &= ~MMC_DMA_SELECT_MASK;
return 0;
}
/*
* Blocks until the card has reached a given physical state,
* as indicated by the present state register.
*
* @param mmc The MMC controller whose state we should wait on
* @param present_state_mask A mask that indicates when we should return.
* Returns when the mask bits are no longer set in present_state if invert is true,
* or true when the mask bits are _set_ in the present state if invert is false.
*
* @return 0 on success, or an error on failure
*/
static int sdmmc_wait_for_physical_state(struct mmc *mmc, uint32_t present_state_mask, bool invert)
{
uint32_t timebase = get_time();
uint32_t condition;
// Retry until the event or an error happens
while (true) {
// Handle timeout.
if (get_time_since(timebase) > mmc->timeout) {
mmc_print(mmc, "timed out waiting for command readiness!");
return ETIMEDOUT;
}
// Read the status, and invert the condition, if necessary.
condition = mmc->regs->present_state & present_state_mask;
if (invert) {
condition = !condition;
}
// Return once our condition is met.
if (condition)
return 0;
}
}
/**
* Blocks until the SD driver is ready for a command,
* or the MMC controller's timeout interval is met.
*
* @param mmc The MMC controller
*/
static int sdmmc_wait_for_command_readiness(struct mmc *mmc)
{
return sdmmc_wait_for_physical_state(mmc, MMC_COMMAND_INHIBIT, true);
}
/**
* Blocks until the SD driver is ready to transmit data,
* or the MMC controller's timeout interval is met.
*
* @param mmc The MMC controller whose data line we should wait for.
*/
static int sdmmc_wait_for_data_readiness(struct mmc *mmc)
{
return sdmmc_wait_for_physical_state(mmc, MMC_DATA_INHIBIT, true);
}
/**
* Blocks until the SD driver's data lines are clear,
* indicating the card is no longer busy.
*
* @param mmc The MMC controller whose data line we should wait for.
*/
static int sdmmc_wait_until_no_longer_busy(struct mmc *mmc)
{
return sdmmc_wait_for_physical_state(mmc, MMC_DAT0_LINE_STATE, false);
}
/**
* Blocks until the SD driver has completed issuing a command.
*
* @param mmc The MMC controller on which to wait.
* @param target_irq A bitmask that specifies the bits that
* will make this function return success
* @param fault_conditions A bitmask that specifies the bits that
* will make this function return EFAULT.
*
* @return 0 on sucess, EFAULT if a fault condition occurs,
* or an error code if a transfer failure occurs
*/
static int sdmmc_wait_for_interrupt(struct mmc *mmc,
uint32_t target_irq, uint32_t fault_conditions)
{
uint32_t timebase = get_time();
// Wait until we either wind up ready, or until we've timed out.
while (true) {
if (get_time_since(timebase) > mmc->timeout)
return ETIMEDOUT;
if (mmc->regs->int_status & fault_conditions)
return EFAULT;
if (mmc->regs->int_status & target_irq)
return 0;
// If an error occurs, return it.
if (mmc->regs->int_status & MMC_STATUS_ERROR_MASK)
return (mmc->regs->int_status & MMC_STATUS_ERROR_MASK);
}
}
/**
* Blocks until the SD driver has completed issuing a command.
*
* @param mmc The MMC controller
*/
static int sdmmc_wait_for_command_completion(struct mmc *mmc)
{
return sdmmc_wait_for_interrupt(mmc, MMC_STATUS_COMMAND_COMPLETE, 0);
}
/**
* Blocks until the SD driver has completed issuing a command.
*
* @param mmc The MMC controller
*/
static int sdmmc_wait_for_transfer_completion(struct mmc *mmc)
{
return sdmmc_wait_for_interrupt(mmc, MMC_STATUS_TRANSFER_COMPLETE, MMC_STATUS_DMA_INTERRUPT);
}
/**
* Returns the block size for a given operation on the MMC controller.
*
* @param mmc The MMC controller for which we're quierying block size.
* @param is_write True iff the given operation is a write.
*/
static uint32_t sdmmc_get_block_size(struct mmc *mmc, bool is_write)
{
// FIXME: support write blocks?
(void)is_write;
return (1 << mmc->read_block_order);
}
/**
* Handles execution of a DATA stage using the CPU, rather than by using DMA.
*
* @param mmc The MMc controller to work with.
* @param blocks The number of blocks to work with.
* @param is_write True iff the data is being set _to_ the CARD.
* @param data_buffer The data buffer to be transmitted or populated.
*
* @return 0 on success, or an error code on failure.
*/
static int sdmmc_handle_cpu_transfer(struct mmc *mmc, uint16_t blocks, bool is_write, void *data_buffer)
{
uint16_t blocks_remaining = blocks;
uint16_t bytes_remaining_in_block;
uint32_t timebase = get_time();
// Get a window that lets us work with the data buffer in 32-bit chunks.
uint32_t *buffer = data_buffer;
// Figure out the mask to check based on whether this is a read or a write.
uint32_t mask = is_write ? MMC_BUFFER_WRITE_ENABLE : MMC_BUFFER_READ_ENABLE;
// While we have blocks left to read...
while (blocks_remaining) {
// Get the number of bytes per block read.
bytes_remaining_in_block = sdmmc_get_block_size(mmc, false);
// Wait for a block read to complete.
while (!(mmc->regs->present_state & mask)) {
// If an error occurs, return it.
if (mmc->regs->int_status & MMC_STATUS_ERROR_MASK) {
return (mmc->regs->int_status & MMC_STATUS_ERROR_MASK);
}
// Check for timeout.
if (get_time_since(timebase) > mmc->timeout)
return ETIMEDOUT;
}
// While we've still bytes left to read.
while (bytes_remaining_in_block) {
// Check for timeout.
if (get_time_since(timebase) > mmc->timeout)
return ETIMEDOUT;
// Transfer the data to the relevant
if (is_write) {
mmc->regs->buffer = *buffer;
} else {
*buffer = mmc->regs->buffer;
}
// Advance by a register size...
bytes_remaining_in_block -= sizeof(mmc->regs->buffer);
++buffer;
}
// Advice by a block...
--blocks_remaining;
}
return 0;
}
/**
* Prepare the data-related registers for command transmission.
*
* @param mmc The device to be used to transmit.
* @param blocks The total number of blocks to be transferred.
* @param is_write True iff we're sending data _to_ the card.
* @param auto_termiante True iff we should instruct the system
* to reclaim the data lines after a transaction.
*/
static void sdmmc_prepare_command_data(struct mmc *mmc, uint16_t blocks,
bool is_write, bool auto_terminate, int argument)
{
if (blocks) {
uint16_t block_size = sdmmc_get_block_size(mmc, is_write);
// If we're using DMA, target our bounce buffer.
if (mmc->use_dma)
mmc->regs->dma_address = (uint32_t)sdmmc_bounce_buffer;
// Set up the DMA block size and count.
// This is synchronized with the size of our bounce buffer.
mmc->regs->block_size = sdmmc_bounce_dma_boundary | block_size;
mmc->regs->block_count = blocks;
}
// Populate the command argument.
mmc->regs->argument = argument;
if (blocks) {
uint32_t to_write = MMC_TRANSFER_LIMIT_BLOCK_COUNT;
// If this controller should use DMA, set that up.
if (mmc->use_dma)
to_write |= MMC_TRANSFER_DMA_ENABLE;
// If this is a multi-block datagram, indicate so.
if (blocks > 1)
to_write |= MMC_TRANSFER_MULTIPLE_BLOCKS;
// If this command should automatically terminate, set the host to
// terminate it after the block span is complete.
if (auto_terminate)
to_write |= MMC_TRANSFER_AUTO_CMD12;
// If this is a read, set the READ mode.
if (!is_write)
to_write |= MMC_TRANSFER_CARD_TO_HOST;
mmc->regs->transfer_mode = to_write;
}
}
/**
* Prepare the command-related registers for command transmission.
*
* @param mmc The device to be used to transmit.
* @param blocks_to_xfer The total number of blocks to be transferred.
* @param command The command number to issue.
* @param response_type The type of response we'll expect.
*/
static void sdmmc_prepare_command_registers(struct mmc *mmc, int blocks_to_xfer,
enum sdmmc_command command, enum sdmmc_response_type response_type, enum sdmmc_response_checks checks)
{
// Populate the command number
uint16_t to_write = (command << MMC_COMMAND_NUMBER_SHIFT) | (response_type << MMC_COMMAND_RESPONSE_TYPE_SHIFT) | checks;
// If this is a "stop transmitting" command, set the abort flag.
if (command == CMD_STOP_TRANSMISSION)
to_write |= MMC_COMMAND_TYPE_ABORT;
// If this command has a data stage, include it.
if (blocks_to_xfer)
to_write |= MMC_COMMAND_HAS_DATA;
// Write our command to the given register.
// This must be all done at once, as writes to this register have semantic meaning.
mmc->regs->command = to_write;
}
/**
* Enables or disables the SDMMC interrupts.
* We leave these masked, but checkt their status in their status register.
*
* @param mmc The eMMC device to work with.
* @param enabled True if interrupts should enabled, or false to disable them.
*/
static void sdmmc_enable_interrupts(struct mmc *mmc, bool enabled)
{
// Get an mask that represents all interrupts.
uint32_t all_interrupts =
MMC_STATUS_COMMAND_COMPLETE | MMC_STATUS_TRANSFER_COMPLETE |
MMC_STATUS_DMA_INTERRUPT | MMC_STATUS_ERROR_MASK;
// Clear any pending interrupts.
mmc->regs->int_status |= all_interrupts;
// And enable or disable the pseudo-interrupts.
if (enabled) {
mmc->regs->int_enable |= all_interrupts;
} else {
mmc->regs->int_enable &= ~all_interrupts;
}
}
/**
* Handle the response to an SDMMC command, copying the data
* from the SDMMC response holding area to the user-provided response buffer.
*/
static int sdmmc_handle_command_response(struct mmc *mmc,
enum sdmmc_response_type type, void *response_buffer)
{
uint32_t *buffer = (uint32_t *)response_buffer;
int rc;
// If we don't have a place to put the response,
// skip copying it out.
if (!response_buffer)
return 0;
switch (type) {
// Easy case: we don't have a response. We don't need to do anything.
case MMC_RESPONSE_NONE:
break;
// If we have a response we have to wait on busy-completion for,
// wait for the DAT0 line to clear.
case MMC_RESPONSE_LEN48_CHK_BUSY:
mmc_print(mmc, "waiting for card to stop being busy...");
rc = sdmmc_wait_until_no_longer_busy(mmc);
if (rc) {
mmc_print(mmc, "failure waiting for card to finish being busy (%d)", rc);
return rc;
}
// (fall-through)
// If we have a 48-bit response, then we have 32 bits of response and 16 bits of CRC/command.
// The naming is a little odd, but that's thanks to the SDMMC standard.
case MMC_RESPONSE_LEN48:
*buffer = mmc->regs->response[0];
break;
// If we have a 136-bit response, we have 128 of response and 8 bits of CRC.
// TODO: validate that this is the right format/endianness/everything
case MMC_RESPONSE_LEN136:
// Copy the response to the buffer manually.
// We avoid memcpy here, because this is volatile.
for(int i = 0; i < 4; ++i)
buffer[i] = mmc->regs->response[i];
break;
default:
mmc_print(mmc, "invalid response type; not handling response");
}
return 0;
}
/**
* Sends a command to the SD card, and awaits a response.
*
* @param mmc The SDMMC device to be used to transmit the command.
* @param response_type The type of response to expect-- mostly specifies the length.
* @param checks Determines which sanity checks the host controller should run.
* @param argument The argument to the SDMMC command.
* @param response_buffer A buffer to store the response. Should be at uint32_t for a LEN48 command,
* or 16 bytes for a LEN136 command. If this arguemnt is NULL, no response will be returned.
* @param blocks_to_transfer The number of SDMMC blocks to be transferred with the given command,
* or 0 to indicate that this command should not expect response data.
* @param is_write True iff the given command issues data _to_ the card, instead of vice versa.
* @param auto_terminate True iff the gven command needs to be terminated with e.g. CMD12
* @param data_buffer A byte buffer that either contains the data to be sent, or which should
* receive data, depending on the is_write argument.
*
* @returns 0 on success, an error number on failure
*/
static int sdmmc_send_command(struct mmc *mmc, enum sdmmc_command command,
enum sdmmc_response_type response_type, enum sdmmc_response_checks checks,
uint32_t argument, void *response_buffer, uint16_t blocks_to_transfer,
bool is_write, bool auto_terminate, void *data_buffer)
{
uint32_t total_data_to_xfer = sdmmc_get_block_size(mmc, is_write) * blocks_to_transfer;
int rc;
// If this transfer would have us send more than we can, fail out.
if (total_data_to_xfer > sizeof(sdmmc_bounce_buffer)) {
mmc_print(mmc, "ERROR: transfer is larger than our maximum DMA transfer size!");
return -E2BIG;
}
// Sanity check: if this is a data transfer, make sure we have a data buffer...
if (blocks_to_transfer && !data_buffer) {
mmc_print(mmc, "ERROR: no data buffer provided, but this is a data transfer!");
return -EINVAL;
}
// Wait until we can issue commands to the device.
rc = sdmmc_wait_for_command_readiness(mmc);
if (rc) {
mmc_print(mmc, "card not willing to accept commands (%d / %08x)", rc, mmc->regs->present_state);
return -EBUSY;
}
// If this is a data command, or a command that uses the data lines for busy-detection.
if (blocks_to_transfer || (response_type == MMC_RESPONSE_LEN48_CHK_BUSY)) {
rc = sdmmc_wait_for_data_readiness(mmc);
if (rc) {
mmc_print(mmc, "card not willing to accept data-commands (%d / %08x)", rc, mmc->regs->present_state);
return -EBUSY;
}
}
// If we have data to send, prepare it.
sdmmc_prepare_command_data(mmc, blocks_to_transfer, is_write, auto_terminate, argument);
// If this is a write and we have data, we'll need to populate the bounce buffer before
// issuing the command.
if (blocks_to_transfer && is_write && mmc->use_dma) {
memcpy(sdmmc_bounce_buffer, data_buffer, total_data_to_xfer);
}
// Configure the controller to send the command.
sdmmc_prepare_command_registers(mmc, blocks_to_transfer, command, response_type, checks);
// Ensure we get the status response we want.
sdmmc_enable_interrupts(mmc, true);
// Wait for the command to be completed.
rc = sdmmc_wait_for_command_completion(mmc);
if (rc) {
mmc_print(mmc, "failed to issue %s (arg=%08x, rc=%d)", sdmmc_get_command_string(command), argument, rc);
mmc_print_command_errors(mmc, rc);
sdmmc_enable_interrupts(mmc, false);
return rc;
}
// Copy the response received to the output buffer, if applicable.
rc = sdmmc_handle_command_response(mmc, response_type, response_buffer);
if (rc) {
mmc_print(mmc, "failed to handle %s response! (%d)", sdmmc_get_command_string(command), rc);
return rc;
}
// If we had a data stage, handle it.
if (blocks_to_transfer) {
// If this is a DMA transfer, wait for its completion.
if (mmc->use_dma) {
// Wait for the transfer to be complete...
rc = sdmmc_wait_for_transfer_completion(mmc);
if (rc) {
mmc_print(mmc, "failed to complete %s data stage via DMA (%d)", sdmmc_get_command_string(command), command, rc);
sdmmc_enable_interrupts(mmc, false);
return rc;
}
// If this is a read, and we've just finished a transfer, copy the data from
// our bounce buffer to the target data buffer.
if (!is_write) {
memcpy(data_buffer, sdmmc_bounce_buffer, total_data_to_xfer);
}
}
// Otherwise, perform the transfer using the CPU.
else {
rc = sdmmc_handle_cpu_transfer(mmc, blocks_to_transfer, is_write, data_buffer);
if (rc) {
mmc_print(mmc, "failed to complete CMD%d data stage via CPU (%d)", command, rc);
sdmmc_enable_interrupts(mmc, false);
return rc;
}
}
}
// Disable resporting psuedo-interrupts.
// (This is mostly for when the GIC is brought up)
sdmmc_enable_interrupts(mmc, false);
mmc_debug(mmc, "completed %s.", sdmmc_get_command_string(command));
return 0;
}
/**
* Convenience function that sends a simple SDMMC command
* and awaits response. Wrapper around sdmmc_send_command.
*
* @param mmc The SDMMC device to be used to transmit the command.
* @param response_type The type of response to expect-- mostly specifies the length.
* @param argument The argument to the SDMMC command.
* @param response_buffer A buffer to store the response. Should be at uint32_t for a LEN48 command,
* or 16 bytes for a LEN136 command.
*
* @returns 0 on success, an error number on failure
*/
static int sdmmc_send_simple_command(struct mmc *mmc, enum sdmmc_command command,
enum sdmmc_response_type response_type, uint32_t argument, void *response_buffer)
{
// If we don't expect a response, don't check; otherwise check everything.
enum sdmmc_response_checks checks = (response_type == MMC_RESPONSE_NONE) ? MMC_CHECKS_NONE : MMC_CHECKS_ALL;
// Deletegate the full checks function.
return sdmmc_send_command(mmc, command, response_type, checks, argument, response_buffer, 0, false, false, NULL);
}
/**
* Sends an SDMMC application command.
*
* @param mmc The SDMMC device to be used to transmit the command.
* @param response_type The type of response to expect-- mostly specifies the length.
* @param checks Determines which sanity checks the host controller should run.
* @param argument The argument to the SDMMC command.
* @param response_buffer A buffer to store the response. Should be at uint32_t for a LEN48 command,
* or 16 bytes for a LEN136 command.
*
* @returns 0 on success, an error number on failure
*/
static int sdmmc_send_simple_app_command(struct mmc *mmc, enum sdmmc_command command,
enum sdmmc_response_type response_type, enum sdmmc_response_checks checks,
uint32_t argument, void *response_buffer)
{
int rc;
// First, send the application command.
rc = sdmmc_send_simple_command(mmc, CMD_APP_COMMAND, MMC_RESPONSE_LEN48, 0, NULL);
if (rc) {
mmc_print(mmc, "failed to prepare application command! (%d)", rc);
return rc;
}
// And issue the body of the command.
return sdmmc_send_command(mmc, command, response_type, checks, argument, response_buffer, 0, false, false, NULL);
}
/**
* Reads a collection of bits from the CSD register.
*
* @param csd An array of four uint32_ts containing the CSD.
* @param start The bit number to start at.
* @param width. The width of the relveant read.
*
* @returns the extracted bits
*/
static uint32_t sdmmc_extract_csd_bits(uint32_t *csd, int start, int width)
{
uint32_t relevant_dword, result;
int offset_into_dword, bits_into_next_dword;
// Sanity check our span.
if ((start + width) > 128) {
printk("MMC ERROR: invalid CSD slice!\n");
return 0xFFFFFFFF;
}
// Figure out where the relevant range is in our CSD.
relevant_dword = csd[start / 32];
offset_into_dword = start % 32;
// Grab all the bits we can from the relevant DWORD.
result = relevant_dword >> offset_into_dword;
// Special case: if we spanned a word boundary, we'll
// need to read one word.
//
// FIXME: I'm writing this at 5AM, and this requires basic arithemtic,
// my greatest weakness. This is going to be stupid wrong.
if (offset_into_dword + width > 32) {
bits_into_next_dword = (offset_into_dword + width) - 32;
// Grab the next dword in the CSD...
relevant_dword = csd[(start / 32) + 1];
// ... mask away the bits higher than the bits we want...
relevant_dword &= (1 << (bits_into_next_dword)) - 1;
// .. and shift the relevant bits up to their position.
relevant_dword <<= (width - bits_into_next_dword);
// Finally, combine in the new word.
result |= relevant_dword;
}
return result;
}
/**
* Parses a fetched CSD per the Version 1 standard.
*
* @param mmc The MMC structure to be populated.
* @param csd A four-dword array containing the read CSD.
*
* @returns int 0 on success, or an error code if the CSD appears invalid
*/
static int sdmmc_parse_csd_version1(struct mmc *mmc, uint32_t *csd)
{
// Get the maximum allowed read-block size.
mmc->read_block_order = sdmmc_extract_csd_bits(csd, MMC_CSD_V1_READ_BL_LENGTH_START, MMC_CSD_V1_READ_BL_LENGTH_WIDTH);
// TODO: handle other attributes
return 0;
}
/**
* Reads the active MMC card's Card Specific Data, and updates the MMC object's properties.
*
* @param mmc The MMC to be queired and updated.
* @returns 0 on success, or an errno on failure
*/
static int sdmmc_read_and_parse_csd(struct mmc *mmc)
{
int rc;
uint32_t csd[4];
uint16_t csd_version;
// Request the CSD from the device.
rc = sdmmc_send_simple_command(mmc, CMD_SEND_CSD, MMC_RESPONSE_LEN136, mmc->relative_address << 16, csd);
if (rc) {
mmc_print(mmc, "could not get the card's CSD!");
return ENODEV;
}
// Figure out the CSD version.
csd_version = sdmmc_extract_csd_bits(csd, MMC_CSD_STRUCTURE_START, MMC_CSD_STRUCTURE_WIDTH);
// Handle each CSD version.
switch (csd_version) {
// Handle version 1 CSDs.
// (The Switch eMMC appears to always use ver1 CSDs.)
case MMC_CSD_VERSION1:
return sdmmc_parse_csd_version1(mmc, csd);
// For now, don't support any others.
default:
mmc_print(mmc, "ERROR: we don't currently support cards with v%d CSDs!", csd_version);
return ENOTTY;
}
}
/**
* Reads the active MMC card's Card Specific Data, and updates the MMC object's properties.
*
* @param mmc The MMC to be queired and updated.
* @returns 0 on success, or an errno on failure
*/
static int sdmmc_read_and_parse_ext_csd(struct mmc *mmc)
{
int rc;
uint8_t ext_csd[MMC_EXT_CSD_SIZE];
// Read the single EXT CSD block.
rc = sdmmc_send_command(mmc, CMD_SEND_EXT_CSD, MMC_RESPONSE_LEN48,
MMC_CHECKS_ALL, 0, NULL, 1, false, false, ext_csd);
if (rc) {
mmc_print(mmc, "ERROR: failed to read the extended CSD!");
return rc;
}
/**
* Parse the extended CSD:
*/
// Hardware partition support.
mmc->partition_support = ext_csd[MMC_EXT_CSD_PARTITION_SUPPORT];
mmc->partition_config = ext_csd[MMC_EXT_CSD_PARTITION_CONFIG] & ~MMC_EXT_CSD_PARTITION_SELECT_MASK;
mmc->partition_switch_time = ext_csd[MMC_EXT_CSD_PARTITION_SWITCH_TIME] * MMC_EXT_CSD_PARTITION_SWITCH_SCALE_US;
mmc->partitioned = ext_csd[MMC_EXT_CSD_PARTITION_SETTING_COMPLETE] & MMC_EXT_CSD_PARTITION_SETTING_COMPLETED;
mmc->partition_attribute = ext_csd[MMC_EXT_CSD_PARTITION_ATTRIBUTE];
return 0;
}
/**
* Decides on a block transfer sized based on the information observed,
* and applies it to the card.
*/
static int sdmmc_set_up_block_transfer_size(struct mmc *mmc)
{
int rc;
// For now, we'll only ever set up 512B blocks, because
// 1) every card supports this, and 2) we use SDMA, which only supports up to 512B
mmc->read_block_order = 9;
// Inform the card of the block size we'll want to use.
rc = sdmmc_send_simple_command(mmc, CMD_SET_BLKLEN, MMC_RESPONSE_LEN48, 1 << mmc->read_block_order, NULL);
if (rc) {
mmc_print(mmc, "could not fetch the CID");
return ENODEV;
}
return 0;
}
/**
* Switches the SDMMC card and controller to the fullest bus width possible.
*
* @param mmc The MMC controller to switch up to a full bus width.
*/
static int sdmmc_switch_bus_width(struct mmc *mmc, enum sdmmc_bus_width width)
{
// Ask the card to adjust to the wider bus width.
int rc = mmc->switch_mode(mmc, MMC_SWITCH_EXTCSD_NORMAL,
MMC_BUS_WIDTH, width, mmc->timeout);
if (rc) {
mmc_print(mmc, "could not switch mode on the card side!");
return rc;
}
// And switch the bus width on our side.
mmc->regs->host_control &= ~MMC_HOST_BUS_WIDTH_MASK;
switch (width) {
case MMC_BUS_WIDTH_4BIT:
mmc->regs->host_control |= MMC_HOST_BUS_WIDTH_4BIT;
break;
case MMC_BUS_WIDTH_8BIT:
mmc->regs->host_control |= MMC_HOST_BUS_WIDTH_8BIT;
break;
default:
break;
}
return 0;
}
/**
* Optimize our SDMMC transfer mode to fully utilize the bus.
*/
static int mmc_optimize_transfer_mode(struct mmc *mmc)
{
int rc;
// Switch the device to its maximum bus width.
rc = sdmmc_switch_bus_width(mmc, mmc->max_bus_width);
if (rc) {
mmc_print(mmc, "could not switch the controller's bus width!");
return rc;
}
// TODO: step up into high speed modes
mmc_print(mmc, "now operating with a wider bus width");
return 0;
}
/**
* Retrieves information about the card, and populates the MMC structure accordingly.
* Used as part of the SDMMC initialization process.
*/
static int sdmmc_set_up_partitions(struct mmc *mmc)
{
// If the card doesn't support partitions, fail out.
if (!(mmc->partition_support & MMC_SUPPORTS_HARDWARE_PARTS))
return ENOTTY;
// If the card hasn't been partitioned, fail out.
// We don't support setting up hardware partitioning.
if (!mmc->partitioned) {
mmc_print(mmc, "NOTE: card supports partitions but is not partitioned");
return ENOTDIR;
}
mmc_print(mmc, "detected a card with hardware partitions.");
// Use partitioning.
return mmc->switch_mode(mmc, MMC_SWITCH_EXTCSD_NORMAL,
MMC_GROUP_ERASE_DEF, MMC_EXT_CSD_ERASE_GROUP_DEF_BIT, mmc->timeout);
}
/**
* Requests that an MMC target use the card's current relative address.
*
* @param mmc The SDMMC controller to work with.
* @return 0 on success, or an error code on failure.
*/
static int sdmmc_set_relative_address(struct mmc *mmc)
{
int rc;
// Set up the card's relative address.
rc = sdmmc_send_simple_command(mmc, CMD_SET_RELATIVE_ADDR, MMC_RESPONSE_LEN48, mmc->relative_address << 16, NULL);
if (rc) {
mmc_print(mmc, "could not set the card's relative address! (%d)", rc);
return rc;
}
return 0;
}
/**
* Requests that an SD target report a relative address for us to use
* to communicate with it.
*
* @param mmc The SDMMC controller to work with.
* @return 0 on success, or an error code on failure.
*/
static int sdmmc_get_relative_address(struct mmc *mmc)
{
int rc;
uint32_t response;
//uint32_t timebase = get_time();
// TODO: do we need to repeatedly retry this? other codebases do
// Set up the card's relative address.
rc = sdmmc_send_simple_command(mmc, CMD_GET_RELATIVE_ADDR, MMC_RESPONSE_LEN48, 0, &response);
if (rc) {
mmc_print(mmc, "could not get the card's relative address! (%d)", rc);
return rc;
}
// Apply the fetched relative address.
mmc->relative_address = response >> 16;
return 0;
}
/**
* Retrieves information about the card, and populates the MMC structure accordingly.
* Used as part of the SDMMC initialization process.
*/
static int sdmmc_card_init(struct mmc *mmc)
{
int rc;
uint32_t response[4];
// Retreive the card ID.
rc = sdmmc_send_simple_command(mmc, CMD_ALL_SEND_CID, MMC_RESPONSE_LEN136, 0, response);
if (rc) {
mmc_print(mmc, "could not fetch the CID");
return rc;
}
// Store the card ID for later.
memcpy(mmc->cid, response, sizeof(mmc->cid));
// Establish a relative address to communicate with
rc = mmc->establish_relative_address(mmc);
if (rc) {
mmc_print(mmc, "could not establish a relative address! (%d)", rc);
return rc;
}
// Read and handle card's Card Specific Data (CSD).
rc = sdmmc_read_and_parse_csd(mmc);
if (rc) {
mmc_print(mmc, "could not populate CSD attributes! (%d)", rc);
return rc;
}
// Select our eMMC card, so it knows we're talking to it.
rc = sdmmc_send_simple_command(mmc, CMD_TOGGLE_CARD_SELECT, MMC_RESPONSE_LEN48, mmc->relative_address << 16, response);
if (rc) {
mmc_print(mmc, "could not select the active card for use! (%d)", rc);
return rc;
}
// Determine the block size we want to work with, and then set up the size accordingly.
rc = sdmmc_set_up_block_transfer_size(mmc);
if (rc) {
mmc_print(mmc, "could not set up block transfer sizes! (%d)", rc);
return rc;
}
return 0;
}
/**
* Blocks until the eMMC card is fully initialized.
*
* @param mmc The MMC device that should do the waiting.
*/
static int sdmmc_mmc_wait_for_card_readiness(struct mmc *mmc)
{
int rc;
uint32_t response[4];
while (true) {
uint32_t response_masked;
// Ask the SD card to identify its state. It will respond with readiness and a capacity magic.
rc = sdmmc_send_command(mmc, CMD_SEND_OPERATING_CONDITIONS, MMC_RESPONSE_LEN48,
MMC_CHECKS_NONE, 0x40000080, response, 0, false, false, NULL);
if (rc) {
mmc_print(mmc, "ERROR: could not read the card's operating conditions!");
return rc;
}
// Validate that this is a valid Switch eMMC.
// Per the spec, any card greater than 2GiB should respond with this magic number.
response_masked = response[0] & MMC_EMMC_OPERATING_COND_CAPACITY_MASK;
if (response_masked != MMC_EMMC_OPERATING_COND_CAPACITY_MAGIC) {
mmc_print(mmc, "ERROR: this doesn't appear to be a valid Switch eMMC!");
return ENOTTY;
}
// If the device has just become ready, we're done!
response_masked = response[0] & MMC_EMMC_OPERATING_READINESS_MASK;
if (response_masked == MMC_EMMC_OPERATING_COND_READY) {
return 0;
}
}
}
/**
* Blocks until the SD card is fully initialized.
*
* @param mmc The MMC device that should do the waiting.
* @aparam response Out argument that recieves the final, ready command response.
* Should have roon for uint32_t.
*/
static int sdmmc_sd_wait_for_card_readiness(struct mmc *mmc, uint32_t *response)
{
int rc;
uint32_t argument = MMC_SD_OPERATING_COND_ACCEPTS_3V3;
// If this is a SDv2 or higher card, check for an SDHC card.
if (mmc->spec_version >= SD_VERSION_2) {
argument |= MMC_SD_OPERATING_COND_HIGH_CAPACITY;
}
while (true) {
// Ask the SD card to identify its state. It will respond with readiness and a capacity magic.
rc = sdmmc_send_simple_app_command(mmc, CMD_APP_SEND_OP_COND,
MMC_RESPONSE_LEN48, MMC_CHECKS_NONE, argument, response);
if (rc) {
mmc_print(mmc, "ERROR: could not read the card's operating conditions!");
return rc;
}
// If the device has just become ready, we're done!
if (response[0] & MMC_SD_OPERATING_COND_READY)
return 0;
// Wait a delay so we're not spamming the card incessantly.
udelay(1000);
}
}
/**
* Handles MMC-specific card initialization.
*/
static int sdmmc_mmc_card_init(struct mmc *mmc)
{
int rc;
mmc_debug(mmc, "setting up card as MMC");
// Bring the bus out of its idle state.
rc = sdmmc_send_simple_command(mmc, CMD_GO_IDLE_OR_INIT, MMC_RESPONSE_NONE, 0, NULL);
if (rc) {
mmc_print(mmc, "could not bring bus to idle!");
return rc;
}
// Wait for the card to finish being busy.
rc = sdmmc_mmc_wait_for_card_readiness(mmc);
if (rc) {
mmc_print(mmc, "card failed to come up! (%d)", rc);
return rc;
}
// Run the common core card initialization.
rc = sdmmc_card_init(mmc);
if (rc) {
mmc_print(mmc, "failed to set up card (%d)!", rc);
return rc;
}
// Switch to a transfer mode that can more efficiently utilize the bus.
/*
rc = mmc_optimize_transfer_mode(mmc);
if (rc) {
mmc_print(mmc, "could not optimize bus utlization! (%d)", rc);
}
*/
(void)mmc_optimize_transfer_mode;
// Read and handle card's Extended Card Specific Data (ext-CSD).
rc = sdmmc_read_and_parse_ext_csd(mmc);
if (rc) {
mmc_print(mmc, "could not populate extended-CSD attributes! (%d)", rc);
return EPIPE;
}
// Set up MMC card partitioning, if supported.
rc = sdmmc_set_up_partitions(mmc);
if (rc) {
mmc_print(mmc, "NOTE: card cannot be used with hardware partitions", rc);
}
return 0;
}
/**
* Evalutes a check pattern response (used with interface commands)
* and validates that it contains our common check pattern.
*
* @param response The response recieved after a given command.
* @return True iff the given response has a valid check pattern.
*/
static bool sdmmc_check_pattern_present(uint32_t response)
{
uint32_t pattern_byte = response & 0xFF;
return pattern_byte == MMC_IF_CHECK_PATTERN;
}
/**
* Handles SD-specific card initialization.
*/
static int sdmmc_sd_card_init(struct mmc *mmc)
{
int rc;
uint32_t ocr, response;
mmc_debug(mmc, "setting up card as SD");
// Bring the bus out of its idle state.
rc = sdmmc_send_simple_command(mmc, CMD_GO_IDLE_OR_INIT, MMC_RESPONSE_NONE, 0, NULL);
if (rc) {
mmc_print(mmc, "could not bring bus to idle!");
return rc;
}
udelay(1000);
// Validate that the card can handle working with the voltages we can provide.
rc = sdmmc_send_simple_command(mmc, CMD_SEND_IF_COND, MMC_RESPONSE_LEN48, MMC_IF_VOLTAGE_3V3 | MMC_IF_CHECK_PATTERN, &response);
if (rc || !sdmmc_check_pattern_present(response)) {
// TODO: This is either a broken, SDv1 or MMC card.
// Handle the latter two cases as best we can.
mmc_print(mmc, "ERROR: this card isn't an SDHC card!");
mmc_print(mmc, " we don't yet support low-capacity cards. :(");
return rc;
}
// If this responded, indicate that this is a v2 card.
else {
// store that this is a v2 card
mmc->spec_version = SD_VERSION_2;
}
// Wait for the card to finish being busy.
rc = sdmmc_sd_wait_for_card_readiness(mmc, &ocr);
if (rc) {
mmc_print(mmc, "card failed to come up! (%d)", rc);
return rc;
}
// If the response indicated this was a high capacity card,
// always use block addressing.
mmc->uses_block_addressing = !!(ocr & MMC_SD_OPERATING_COND_HIGH_CAPACITY);
// Run the common core card initialization.
rc = sdmmc_card_init(mmc);
if (rc) {
mmc_print(mmc, "failed to set up card (%d)!", rc);
return rc;
}
// FIXME: optimize bus utilization here?
// is this just a call to the same routine as for eMMC?
return 0;
}
/**
* @returns true iff the given READ_STATUS response indicates readiness
*/
static bool sdmmc_status_indicates_readiness(uint32_t status)
{
// If the card is currently programming, it's not ready.
if ((status & MMC_STATUS_MASK) == MMC_STATUS_PROGRAMMING)
return false;
// Return true iff the card is ready for data.
return status & MMC_STATUS_READY_FOR_DATA;
}
/**
* Waits for card readiness; should be issued after e.g. enabling partitioning.
*
* @param mmc The MMC to wait on.
* @param 0 if the wait completed with the card being ready; or an error code otherwise
*/
static int sdmmc_wait_for_card_ready(struct mmc *mmc, uint32_t timeout)
{
int rc;
uint32_t status;
uint32_t timebase = get_time();
while (true) {
// Read the card's status.
rc = sdmmc_send_simple_command(mmc, CMD_READ_STATUS, MMC_RESPONSE_LEN48, mmc->relative_address << 16, &status);
// Ensure we haven't timed out.
if (get_time_since(timebase) > timeout)
return ETIMEDOUT;
// If we couldn't read, try again.
if (rc)
continue;
// Check to see if we hit a fatal error.
if (status & MMC_STATUS_CHECK_ERROR)
return EPIPE;
// Check for ready status.
if (sdmmc_status_indicates_readiness(status))
return 0;
}
}
/**
* Issues a SWITCH_MODE command, which can be used to write registers on the MMC card's controller,
* and thus to e.g. switch partitions.
*
* @param mmc The MMC device to use for comms.
* @param mode The access mode with which to access the controller.
* @param field The field to access.
* @param value The argument to the access mode.
* @param timeout The timeout, which is often longer than the normal MMC timeout.
*
* @return 0 on success, or an error code on failure
*/
static int sdmmc_mmc_switch_mode(struct mmc *mmc, enum sdmmc_switch_access_mode mode, enum sdmmc_switch_field field, uint16_t value, uint32_t timeout)
{
// Collapse our various parameters into a single argument.
uint32_t argument =
(mode << MMC_SWITCH_ACCESS_MODE_SHIFT) |
(field << MMC_SWITCH_FIELD_SHIFT) |
(value << MMC_SWITCH_VALUE_SHIFT);
// Issue the switch mode command.
int rc = sdmmc_send_simple_command(mmc, CMD_SWITCH_MODE, MMC_RESPONSE_LEN48_CHK_BUSY, argument, NULL);
if (rc){
mmc_print(mmc, "failed to issue SWITCH_MODE command! (%d / %d / %d; rc=%d)", mode, field, value, rc);
return rc;
}
// Wait until we have a sense of the card status to return.
if (timeout != 0) {
rc = sdmmc_wait_for_card_ready(mmc, timeout);
if (rc){
mmc_print(mmc, "failed to talk to the card after SWITCH_MODE (%d)", rc);
return rc;
}
}
return 0;
}
/**
* Issues a SWITCH_MODE command, which can be used to write registers on the SD card's controller,
* and thus to e.g. switch partitions.
*
* @param mmc The MMC device to use for comms.
* @param mode The access mode with which to access the controller.
* @param field The field to access.
* @param value The argument to the access mode.
* @param timeout The timeout, which is often longer than the normal MMC timeout.
*
* @return 0 on success, or an error code on failure
*/
static int sdmmc_sd_switch_mode(struct mmc *mmc, enum sdmmc_switch_access_mode mode, enum sdmmc_switch_field field, uint16_t value, uint32_t timeout)
{
mmc_print(mmc, "ERROR: SD card mode switching not yet implemented");
return ENOSYS;
}
/**
* @return True iff the given MMC card supports hardare partitions.
*/
static bool sdmmc_supports_hardware_partitions(struct mmc *mmc)
{
return mmc->partition_support & MMC_SUPPORTS_HARDWARE_PARTS;
}
/**
* card detect method for built-in cards.
*/
bool sdmmc_builtin_card_present(struct mmc *mmc)
{
return true;
}
/**
* card detect method for GPIO-based card detects
*/
bool sdmmc_external_card_present(struct mmc *mmc)
{
return !gpio_read(mmc->card_detect_gpio);
}
/**
* Switches a given SDMMC Controller where
*/
static void sdmmc_apply_card_type(struct mmc *mmc, enum sdmmc_card_type type)
{
// Store the card type for our own reference...
mmc->card_type = type;
// Set up our per-protocol function pointers.
switch (type) {
// MMC-protoco cards
case MMC_CARD_EMMC:
case MMC_CARD_MMC:
mmc->card_init = sdmmc_mmc_card_init;
mmc->establish_relative_address = sdmmc_set_relative_address;
mmc->switch_mode = sdmmc_mmc_switch_mode;
break;
// SD-protocol cards
case MMC_CARD_SD:
mmc->card_init = sdmmc_sd_card_init;
mmc->establish_relative_address = sdmmc_get_relative_address;
mmc->switch_mode = sdmmc_sd_switch_mode;
break;
// Switch-cart protocol cards
case MMC_CARD_CART:
printk("BUG: trying to use an impossible code path!\n");
panic(0);
}
}
/**
* Populates the given MMC object with defaults for its controller.
*
* @param mmc The mmc object to populate.
*/
static int sdmmc_initialize_defaults(struct mmc *mmc)
{
// Set up based on the controller
switch (mmc->controller) {
case SWITCH_EMMC:
mmc->name = "eMMC";
mmc->max_bus_width = MMC_BUS_WIDTH_8BIT;
mmc->operating_voltage = MMC_VOLTAGE_1V8;
// Set up function pointers for each of our per-instance functions.
mmc->set_up_clock_and_io = sdmmc4_set_up_clock_and_io;
mmc->enable_supplies = sdmmc4_enable_supplies;
mmc->card_present = sdmmc_builtin_card_present;
// The EMMC controller always uses an EMMC card.
sdmmc_apply_card_type(mmc, MMC_CARD_EMMC);
// The Switch's eMMC always uses block addressing.
mmc->uses_block_addressing = true;
break;
case SWITCH_MICROSD:
mmc->name = "uSD";
mmc->card_type = MMC_CARD_SD;
mmc->max_bus_width = MMC_BUS_WIDTH_4BIT;
mmc->operating_voltage = MMC_VOLTAGE_3V3;
mmc->card_detect_gpio = GPIO_MICROSD_CARD_DETECT;
// For the microSD card slot, assume we have an SD-type card.
// Negotiation has a chance to change this, later.
mmc->set_up_clock_and_io = sdmmc1_set_up_clock_and_io;
mmc->enable_supplies = sdmmc1_enable_supplies;
mmc->card_present = sdmmc_external_card_present;
sdmmc_apply_card_type(mmc, MMC_CARD_SD);
// Start off assuming byte addressing; we'll detect and correct this
// later, if necessary.
mmc->uses_block_addressing = false;
break;
default:
printk("ERROR: initialization not yet writen for SDMMC%d", mmc->controller + 1);
return ENOSYS;
}
return 0;
}
/**
* Set up a new SDMMC driver.
* FIXME: clean up!
*
* @param mmc The SDMMC structure to be initiailized with the device state.
* @param controler The controller description to be used; usually SWITCH_EMMC
* or SWTICH_MICROSD.
*/
int sdmmc_init(struct mmc *mmc, enum sdmmc_controller controller)
{
int rc;
// Get a reference to the registers for the relevant SDMMC controller.
mmc->controller = controller;
mmc->regs = sdmmc_get_regs(controller);
// Set the defaults for the card, including the default function pointers
// for the assumed card type, and the per-controller options.
rc = sdmmc_initialize_defaults(mmc);
if (rc) {
printk("ERROR: controller SDMMC%d not currently supported!\n", controller + 1);
return rc;
}
// Default to a timeout of 1S.
mmc->timeout = 1000000;
mmc->partition_switch_time = 1000;
// Use DMA, by default.
mmc->use_dma = true;
// Don't allow writing unless the caller explicitly enables it.
mmc->write_enable = SDMMC_WRITE_DISABLED;
// Default to relative address of zero.
mmc->relative_address = 0;
// Initialize the raw SDMMC controller.
rc = sdmmc_hardware_init(mmc);
if (rc) {
mmc_print(mmc, "failed to set up controller! (%d)", rc);
return rc;
}
// ... and verify that the card is there.
if (!mmc->card_present(mmc)) {
mmc_print(mmc, "ERROR: no card detected!");
return ENODEV;
}
// Handle the initialization that's specific to the card type.
rc = mmc->card_init(mmc);
if (rc) {
mmc_print(mmc, "failed to set run card-specific initialization (%d)!", rc);
return rc;
}
return 0;
}
/**
* Selects the active MMC partition. Can be used to select
* boot partitions for access. Affects all operations going forward.
*
* @param mmc The MMC controller whose card is to be used.
* @param partition The partition number to be selected.
*
* @return 0 on success, or an error code on failure.
*/
int sdmmc_select_partition(struct mmc *mmc, enum sdmmc_partition partition)
{
uint16_t argument = partition;
int rc;
// If we're trying to access hardware partitions on a device that doesn't support them,
// bail out.
if (!sdmmc_supports_hardware_partitions(mmc))
return ENOTTY;
// Set the PARTITION_CONFIG register to select the active partition.
mmc_print(mmc, "switching to partition %d", partition);
rc = mmc->switch_mode(mmc, MMC_SWITCH_MODE_WRITE_BYTE, MMC_PARTITION_CONFIG, argument, 0);
if (rc) {
mmc_print(mmc, "failed to select partition %d (%02x, rc=%d)", partition, argument, rc);
}
mmc_print(mmc, "waiting for %d us", mmc->partition_switch_time);
udelay(mmc->partition_switch_time);
return rc;
}
/**
* Reads a sector or sectors from a given SD/MMC card.
*
* @param mmc The MMC device to work with.
* @param buffer The output buffer to target.
* @param block The sector number to read.
* @param count The number of sectors to read.
*
* @return 0 on success, or an error code on failure.
*/
int sdmmc_read(struct mmc *mmc, void *buffer, uint32_t block, unsigned int count)
{
uint32_t command = (count == 1) ? CMD_READ_SINGLE_BLOCK : CMD_READ_MULTIPLE_BLOCK;
// Determine the argument, which indicates which address we're reading/writing.
uint32_t extent = block;
// If this card uses byte addressing rather than sector addressing,
// multiply by the block size.
if (!mmc->uses_block_addressing) {
extent *= sdmmc_get_block_size(mmc, false);
}
// Execute the relevant read.
return sdmmc_send_command(mmc, command, MMC_RESPONSE_LEN48, MMC_CHECKS_ALL, extent, NULL, count, false, count > 1, buffer);
}
/**
* Releases the SDMMC write lockout, enabling access to the card.
* Note that by default, setting this to WRITE_ENABLED will not allow access to eMMC.
* Check the source for a third constant that can be used to enable eMMC writes.
*
* @param perms The permissions to apply-- typically WRITE_DISABLED or WRITE_ENABLED.
*/
void sdmmc_set_write_enable(struct mmc *mmc, enum sdmmc_write_permission perms)
{
mmc->write_enable = perms;
}
/**
* Writes a sector or sectors to a given SD/MMC card.
*
* @param mmc The MMC device to work with.
* @param buffer The input buffer to write.
* @param block The sector number to write from.
* @param count The number of sectors to write.
*
* @return 0 on success, or an error code on failure.
*/
int sdmmc_write(struct mmc *mmc, void *buffer, uint32_t block, unsigned int count)
{
// Sanity check variables: we're especially careful about allowing writes to the switch eMMC.
bool is_emmc = (mmc->controller == SWITCH_EMMC);
bool allow_mmc_write = (mmc->write_enable == SDMMC_WRITE_ENABLED_INCLUDING_EMMC);
uint32_t command = (count == 1) ? CMD_WRITE_SINGLE_BLOCK : CMD_WRITE_MULTIPLE_BLOCK;
// Determine the argument, which indicates which address we're reading/writing.
uint32_t extent = block;
// If we don't have an explict write enable, don't allow writes.
if (mmc->write_enable == SDMMC_WRITE_DISABLED) {
mmc_print(mmc, "tried to write to an external card, but write was not enabled!");
return EACCES;
}
// Explicitly protect the switch's eMMC to prevent bricks.
if (is_emmc && !allow_mmc_write) {
mmc_print(mmc, "cowardly refusing to write to the switch's eMMMC");
return EACCES;
}
// If this card uses byte addressing rather than sector addressing,
// multiply by the block size.
if (!mmc->uses_block_addressing) {
extent *= sdmmc_get_block_size(mmc, false);
}
// Execute the relevant read.
return sdmmc_send_command(mmc, command, MMC_RESPONSE_LEN48, MMC_CHECKS_ALL, extent, NULL, count, true, count > 1, buffer);
}
/**
* Checks to see whether an SD card is present.
*
* @mmc mmc The controller with which to check for card presence.
* @return true iff a card is present
*/
bool sdmmc_card_present(struct mmc *mmc)
{
return mmc->card_present(mmc);
}
