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u-boot/drivers/mmc/bcm2835_sdhost.c
Alexander Graf c8a73a26d6 mmc: Add bcm2835 sdhost controller 
The BCM2835 family of SoCs has 2 different SD controllers: One based on
the SDHCI spec and a custom, home-grown one.

This patch implements a driver for the latter based on the Linux driver.
This is needed so that we can make use of device trees that assume driver
presence of both SD controllers.

Signed-off-by: Alexander Graf <agraf@suse.de>
2018-01-28 12:27:32 -05:00

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/*
* bcm2835 sdhost driver.
*
* The 2835 has two SD controllers: The Arasan sdhci controller
* (supported by the iproc driver) and a custom sdhost controller
* (supported by this driver).
*
* The sdhci controller supports both sdcard and sdio. The sdhost
* controller supports the sdcard only, but has better performance.
* Also note that the rpi3 has sdio wifi, so driving the sdcard with
* the sdhost controller allows to use the sdhci controller for wifi
* support.
*
* The configuration is done by devicetree via pin muxing. Both
* SD controller are available on the same pins (2 pin groups = pin 22
* to 27 + pin 48 to 53). So it's possible to use both SD controllers
* at the same time with different pin groups.
*
* This code was ported to U-Boot by
* Alexander Graf <agraf@suse.de>
* and is based on drivers/mmc/host/bcm2835.c in Linux which is written by
* Phil Elwell <phil@raspberrypi.org>
* Copyright (C) 2015-2016 Raspberry Pi (Trading) Ltd.
* which is based on
* mmc-bcm2835.c by Gellert Weisz
* which is, in turn, based on
* sdhci-bcm2708.c by Broadcom
* sdhci-bcm2835.c by Stephen Warren and Oleksandr Tymoshenko
* sdhci.c and sdhci-pci.c by Pierre Ossman
*
* SPDX-License-Identifier: GPL-2.0
*/
#include <clk.h>
#include <common.h>
#include <dm.h>
#include <mmc.h>
#include <asm/arch/msg.h>
#include <asm/unaligned.h>
#include <linux/compat.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/sizes.h>
#include <mach/gpio.h>
#include <power/regulator.h>
DECLARE_GLOBAL_DATA_PTR;
#define msleep(a) udelay(a * 1000)
#define SDCMD 0x00 /* Command to SD card - 16 R/W */
#define SDARG 0x04 /* Argument to SD card - 32 R/W */
#define SDTOUT 0x08 /* Start value for timeout counter - 32 R/W */
#define SDCDIV 0x0c /* Start value for clock divider - 11 R/W */
#define SDRSP0 0x10 /* SD card response (31:0) - 32 R */
#define SDRSP1 0x14 /* SD card response (63:32) - 32 R */
#define SDRSP2 0x18 /* SD card response (95:64) - 32 R */
#define SDRSP3 0x1c /* SD card response (127:96) - 32 R */
#define SDHSTS 0x20 /* SD host status - 11 R/W */
#define SDVDD 0x30 /* SD card power control - 1 R/W */
#define SDEDM 0x34 /* Emergency Debug Mode - 13 R/W */
#define SDHCFG 0x38 /* Host configuration - 2 R/W */
#define SDHBCT 0x3c /* Host byte count (debug) - 32 R/W */
#define SDDATA 0x40 /* Data to/from SD card - 32 R/W */
#define SDHBLC 0x50 /* Host block count (SDIO/SDHC) - 9 R/W */
#define SDCMD_NEW_FLAG 0x8000
#define SDCMD_FAIL_FLAG 0x4000
#define SDCMD_BUSYWAIT 0x800
#define SDCMD_NO_RESPONSE 0x400
#define SDCMD_LONG_RESPONSE 0x200
#define SDCMD_WRITE_CMD 0x80
#define SDCMD_READ_CMD 0x40
#define SDCMD_CMD_MASK 0x3f
#define SDCDIV_MAX_CDIV 0x7ff
#define SDHSTS_BUSY_IRPT 0x400
#define SDHSTS_BLOCK_IRPT 0x200
#define SDHSTS_SDIO_IRPT 0x100
#define SDHSTS_REW_TIME_OUT 0x80
#define SDHSTS_CMD_TIME_OUT 0x40
#define SDHSTS_CRC16_ERROR 0x20
#define SDHSTS_CRC7_ERROR 0x10
#define SDHSTS_FIFO_ERROR 0x08
#define SDHSTS_DATA_FLAG 0x01
#define SDHSTS_CLEAR_MASK (SDHSTS_BUSY_IRPT | \
SDHSTS_BLOCK_IRPT | \
SDHSTS_SDIO_IRPT | \
SDHSTS_REW_TIME_OUT | \
SDHSTS_CMD_TIME_OUT | \
SDHSTS_CRC16_ERROR | \
SDHSTS_CRC7_ERROR | \
SDHSTS_FIFO_ERROR)
#define SDHSTS_TRANSFER_ERROR_MASK (SDHSTS_CRC7_ERROR | \
SDHSTS_CRC16_ERROR | \
SDHSTS_REW_TIME_OUT | \
SDHSTS_FIFO_ERROR)
#define SDHSTS_ERROR_MASK (SDHSTS_CMD_TIME_OUT | \
SDHSTS_TRANSFER_ERROR_MASK)
#define SDHCFG_BUSY_IRPT_EN BIT(10)
#define SDHCFG_BLOCK_IRPT_EN BIT(8)
#define SDHCFG_SDIO_IRPT_EN BIT(5)
#define SDHCFG_DATA_IRPT_EN BIT(4)
#define SDHCFG_SLOW_CARD BIT(3)
#define SDHCFG_WIDE_EXT_BUS BIT(2)
#define SDHCFG_WIDE_INT_BUS BIT(1)
#define SDHCFG_REL_CMD_LINE BIT(0)
#define SDVDD_POWER_OFF 0
#define SDVDD_POWER_ON 1
#define SDEDM_FORCE_DATA_MODE BIT(19)
#define SDEDM_CLOCK_PULSE BIT(20)
#define SDEDM_BYPASS BIT(21)
#define SDEDM_FIFO_FILL_SHIFT 4
#define SDEDM_FIFO_FILL_MASK 0x1f
static u32 edm_fifo_fill(u32 edm)
{
return (edm >> SDEDM_FIFO_FILL_SHIFT) & SDEDM_FIFO_FILL_MASK;
}
#define SDEDM_WRITE_THRESHOLD_SHIFT 9
#define SDEDM_READ_THRESHOLD_SHIFT 14
#define SDEDM_THRESHOLD_MASK 0x1f
#define SDEDM_FSM_MASK 0xf
#define SDEDM_FSM_IDENTMODE 0x0
#define SDEDM_FSM_DATAMODE 0x1
#define SDEDM_FSM_READDATA 0x2
#define SDEDM_FSM_WRITEDATA 0x3
#define SDEDM_FSM_READWAIT 0x4
#define SDEDM_FSM_READCRC 0x5
#define SDEDM_FSM_WRITECRC 0x6
#define SDEDM_FSM_WRITEWAIT1 0x7
#define SDEDM_FSM_POWERDOWN 0x8
#define SDEDM_FSM_POWERUP 0x9
#define SDEDM_FSM_WRITESTART1 0xa
#define SDEDM_FSM_WRITESTART2 0xb
#define SDEDM_FSM_GENPULSES 0xc
#define SDEDM_FSM_WRITEWAIT2 0xd
#define SDEDM_FSM_STARTPOWDOWN 0xf
#define SDDATA_FIFO_WORDS 16
#define FIFO_READ_THRESHOLD 4
#define FIFO_WRITE_THRESHOLD 4
#define SDDATA_FIFO_PIO_BURST 8
#define SDHST_TIMEOUT_MAX_USEC 100000
struct bcm2835_plat {
struct mmc_config cfg;
struct mmc mmc;
};
struct bcm2835_host {
void __iomem *ioaddr;
u32 phys_addr;
int clock; /* Current clock speed */
unsigned int max_clk; /* Max possible freq */
unsigned int blocks; /* remaining PIO blocks */
int irq; /* Device IRQ */
u32 ns_per_fifo_word;
/* cached registers */
u32 hcfg;
u32 cdiv;
struct mmc_cmd *cmd; /* Current command */
struct mmc_data *data; /* Current data request */
bool data_complete:1;/* Data finished before cmd */
bool use_busy:1; /* Wait for busy interrupt */
bool wait_data_complete:1; /* Wait for data */
/* for threaded irq handler */
bool irq_block;
bool irq_busy;
bool irq_data;
struct udevice *dev;
struct mmc *mmc;
struct bcm2835_plat *plat;
};
static void bcm2835_dumpregs(struct bcm2835_host *host)
{
dev_dbg(dev, "=========== REGISTER DUMP ===========\n");
dev_dbg(dev, "SDCMD 0x%08x\n", readl(host->ioaddr + SDCMD));
dev_dbg(dev, "SDARG 0x%08x\n", readl(host->ioaddr + SDARG));
dev_dbg(dev, "SDTOUT 0x%08x\n", readl(host->ioaddr + SDTOUT));
dev_dbg(dev, "SDCDIV 0x%08x\n", readl(host->ioaddr + SDCDIV));
dev_dbg(dev, "SDRSP0 0x%08x\n", readl(host->ioaddr + SDRSP0));
dev_dbg(dev, "SDRSP1 0x%08x\n", readl(host->ioaddr + SDRSP1));
dev_dbg(dev, "SDRSP2 0x%08x\n", readl(host->ioaddr + SDRSP2));
dev_dbg(dev, "SDRSP3 0x%08x\n", readl(host->ioaddr + SDRSP3));
dev_dbg(dev, "SDHSTS 0x%08x\n", readl(host->ioaddr + SDHSTS));
dev_dbg(dev, "SDVDD 0x%08x\n", readl(host->ioaddr + SDVDD));
dev_dbg(dev, "SDEDM 0x%08x\n", readl(host->ioaddr + SDEDM));
dev_dbg(dev, "SDHCFG 0x%08x\n", readl(host->ioaddr + SDHCFG));
dev_dbg(dev, "SDHBCT 0x%08x\n", readl(host->ioaddr + SDHBCT));
dev_dbg(dev, "SDHBLC 0x%08x\n", readl(host->ioaddr + SDHBLC));
dev_dbg(dev, "===========================================\n");
}
static void bcm2835_reset_internal(struct bcm2835_host *host)
{
u32 temp;
writel(SDVDD_POWER_OFF, host->ioaddr + SDVDD);
writel(0, host->ioaddr + SDCMD);
writel(0, host->ioaddr + SDARG);
/* Set timeout to a big enough value so we don't hit it */
writel(0xf00000, host->ioaddr + SDTOUT);
writel(0, host->ioaddr + SDCDIV);
/* Clear status register */
writel(SDHSTS_CLEAR_MASK, host->ioaddr + SDHSTS);
writel(0, host->ioaddr + SDHCFG);
writel(0, host->ioaddr + SDHBCT);
writel(0, host->ioaddr + SDHBLC);
/* Limit fifo usage due to silicon bug */
temp = readl(host->ioaddr + SDEDM);
temp &= ~((SDEDM_THRESHOLD_MASK << SDEDM_READ_THRESHOLD_SHIFT) |
(SDEDM_THRESHOLD_MASK << SDEDM_WRITE_THRESHOLD_SHIFT));
temp |= (FIFO_READ_THRESHOLD << SDEDM_READ_THRESHOLD_SHIFT) |
(FIFO_WRITE_THRESHOLD << SDEDM_WRITE_THRESHOLD_SHIFT);
writel(temp, host->ioaddr + SDEDM);
/* Wait for FIFO threshold to populate */
msleep(20);
writel(SDVDD_POWER_ON, host->ioaddr + SDVDD);
/* Wait for all components to go through power on cycle */
msleep(20);
host->clock = 0;
writel(host->hcfg, host->ioaddr + SDHCFG);
writel(host->cdiv, host->ioaddr + SDCDIV);
}
static int bcm2835_finish_command(struct bcm2835_host *host);
static void bcm2835_wait_transfer_complete(struct bcm2835_host *host)
{
int timediff;
u32 alternate_idle;
alternate_idle = (host->data->flags & MMC_DATA_READ) ?
SDEDM_FSM_READWAIT : SDEDM_FSM_WRITESTART1;
timediff = 0;
while (1) {
u32 edm, fsm;
edm = readl(host->ioaddr + SDEDM);
fsm = edm & SDEDM_FSM_MASK;
if ((fsm == SDEDM_FSM_IDENTMODE) ||
(fsm == SDEDM_FSM_DATAMODE))
break;
if (fsm == alternate_idle) {
writel(edm | SDEDM_FORCE_DATA_MODE,
host->ioaddr + SDEDM);
break;
}
/* Error out after 100000 register reads (~1s) */
if (timediff++ == 100000) {
dev_err(host->dev,
"wait_transfer_complete - still waiting after %d retries\n",
timediff);
bcm2835_dumpregs(host);
return;
}
}
}
static int bcm2835_transfer_block_pio(struct bcm2835_host *host, bool is_read)
{
struct mmc_data *data = host->data;
size_t blksize = data->blocksize;
int copy_words;
u32 hsts = 0;
u32 *buf;
if (blksize % sizeof(u32))
return -EINVAL;
buf = is_read ? (u32 *)data->dest : (u32 *)data->src;
if (is_read)
data->dest += blksize;
else
data->src += blksize;
copy_words = blksize / sizeof(u32);
/*
* Copy all contents from/to the FIFO as far as it reaches,
* then wait for it to fill/empty again and rewind.
*/
while (copy_words) {
int burst_words, words;
u32 edm;
burst_words = min(SDDATA_FIFO_PIO_BURST, copy_words);
edm = readl(host->ioaddr + SDEDM);
if (is_read)
words = edm_fifo_fill(edm);
else
words = SDDATA_FIFO_WORDS - edm_fifo_fill(edm);
if (words < burst_words) {
int fsm_state = (edm & SDEDM_FSM_MASK);
if ((is_read &&
(fsm_state != SDEDM_FSM_READDATA &&
fsm_state != SDEDM_FSM_READWAIT &&
fsm_state != SDEDM_FSM_READCRC)) ||
(!is_read &&
(fsm_state != SDEDM_FSM_WRITEDATA &&
fsm_state != SDEDM_FSM_WRITESTART1 &&
fsm_state != SDEDM_FSM_WRITESTART2))) {
hsts = readl(host->ioaddr + SDHSTS);
printf("fsm %x, hsts %08x\n", fsm_state, hsts);
if (hsts & SDHSTS_ERROR_MASK)
break;
}
continue;
} else if (words > copy_words) {
words = copy_words;
}
copy_words -= words;
/* Copy current chunk to/from the FIFO */
while (words) {
if (is_read)
*(buf++) = readl(host->ioaddr + SDDATA);
else
writel(*(buf++), host->ioaddr + SDDATA);
words--;
}
}
return 0;
}
static int bcm2835_transfer_pio(struct bcm2835_host *host)
{
u32 sdhsts;
bool is_read;
int ret = 0;
is_read = (host->data->flags & MMC_DATA_READ) != 0;
ret = bcm2835_transfer_block_pio(host, is_read);
if (host->wait_data_complete)
bcm2835_wait_transfer_complete(host);
sdhsts = readl(host->ioaddr + SDHSTS);
if (sdhsts & (SDHSTS_CRC16_ERROR |
SDHSTS_CRC7_ERROR |
SDHSTS_FIFO_ERROR)) {
printf("%s transfer error - HSTS %08x\n",
is_read ? "read" : "write", sdhsts);
ret = -EILSEQ;
} else if ((sdhsts & (SDHSTS_CMD_TIME_OUT |
SDHSTS_REW_TIME_OUT))) {
printf("%s timeout error - HSTS %08x\n",
is_read ? "read" : "write", sdhsts);
ret = -ETIMEDOUT;
}
return ret;
}
static void bcm2835_set_transfer_irqs(struct bcm2835_host *host)
{
u32 all_irqs = SDHCFG_DATA_IRPT_EN | SDHCFG_BLOCK_IRPT_EN |
SDHCFG_BUSY_IRPT_EN;
host->hcfg = (host->hcfg & ~all_irqs) |
SDHCFG_DATA_IRPT_EN |
SDHCFG_BUSY_IRPT_EN;
writel(host->hcfg, host->ioaddr + SDHCFG);
}
static
void bcm2835_prepare_data(struct bcm2835_host *host, struct mmc_cmd *cmd,
struct mmc_data *data)
{
WARN_ON(host->data);
host->data = data;
if (!data)
return;
host->wait_data_complete = cmd->cmdidx != MMC_CMD_READ_MULTIPLE_BLOCK;
host->data_complete = false;
/* Use PIO */
host->blocks = data->blocks;
bcm2835_set_transfer_irqs(host);
writel(data->blocksize, host->ioaddr + SDHBCT);
writel(data->blocks, host->ioaddr + SDHBLC);
}
static u32 bcm2835_read_wait_sdcmd(struct bcm2835_host *host)
{
u32 value;
int ret;
int timeout_us = SDHST_TIMEOUT_MAX_USEC;
ret = readl_poll_timeout(host->ioaddr + SDCMD, value,
!(value & SDCMD_NEW_FLAG), timeout_us);
if (ret == -ETIMEDOUT)
printf("%s: timeout (%d us)\n", __func__, timeout_us);
return value;
}
static int bcm2835_send_command(struct bcm2835_host *host, struct mmc_cmd *cmd,
struct mmc_data *data)
{
u32 sdcmd, sdhsts;
WARN_ON(host->cmd);
if ((cmd->resp_type & MMC_RSP_136) && (cmd->resp_type & MMC_RSP_BUSY)) {
printf("unsupported response type!\n");
return -EINVAL;
}
sdcmd = bcm2835_read_wait_sdcmd(host);
if (sdcmd & SDCMD_NEW_FLAG) {
printf("previous command never completed.\n");
bcm2835_dumpregs(host);
return -EBUSY;
}
host->cmd = cmd;
/* Clear any error flags */
sdhsts = readl(host->ioaddr + SDHSTS);
if (sdhsts & SDHSTS_ERROR_MASK)
writel(sdhsts, host->ioaddr + SDHSTS);
bcm2835_prepare_data(host, cmd, data);
writel(cmd->cmdarg, host->ioaddr + SDARG);
sdcmd = cmd->cmdidx & SDCMD_CMD_MASK;
host->use_busy = false;
if (!(cmd->resp_type & MMC_RSP_PRESENT)) {
sdcmd |= SDCMD_NO_RESPONSE;
} else {
if (cmd->resp_type & MMC_RSP_136)
sdcmd |= SDCMD_LONG_RESPONSE;
if (cmd->resp_type & MMC_RSP_BUSY) {
sdcmd |= SDCMD_BUSYWAIT;
host->use_busy = true;
}
}
if (data) {
if (data->flags & MMC_DATA_WRITE)
sdcmd |= SDCMD_WRITE_CMD;
if (data->flags & MMC_DATA_READ)
sdcmd |= SDCMD_READ_CMD;
}
writel(sdcmd | SDCMD_NEW_FLAG, host->ioaddr + SDCMD);
return 0;
}
static int bcm2835_transfer_complete(struct bcm2835_host *host)
{
int ret = 0;
WARN_ON(!host->data_complete);
host->data = NULL;
return ret;
}
static void bcm2835_finish_data(struct bcm2835_host *host)
{
host->hcfg &= ~(SDHCFG_DATA_IRPT_EN | SDHCFG_BLOCK_IRPT_EN);
writel(host->hcfg, host->ioaddr + SDHCFG);
host->data_complete = true;
if (host->cmd) {
/* Data managed to finish before the
* command completed. Make sure we do
* things in the proper order.
*/
dev_dbg(dev, "Finished early - HSTS %08x\n",
readl(host->ioaddr + SDHSTS));
} else {
bcm2835_transfer_complete(host);
}
}
static int bcm2835_finish_command(struct bcm2835_host *host)
{
struct mmc_cmd *cmd = host->cmd;
u32 sdcmd;
int ret = 0;
sdcmd = bcm2835_read_wait_sdcmd(host);
/* Check for errors */
if (sdcmd & SDCMD_NEW_FLAG) {
printf("command never completed.\n");
bcm2835_dumpregs(host);
return -EIO;
} else if (sdcmd & SDCMD_FAIL_FLAG) {
u32 sdhsts = readl(host->ioaddr + SDHSTS);
/* Clear the errors */
writel(SDHSTS_ERROR_MASK, host->ioaddr + SDHSTS);
if (!(sdhsts & SDHSTS_CRC7_ERROR) ||
(host->cmd->cmdidx != MMC_CMD_SEND_OP_COND)) {
if (sdhsts & SDHSTS_CMD_TIME_OUT) {
ret = -ETIMEDOUT;
} else {
printf("unexpected command %d error\n",
host->cmd->cmdidx);
bcm2835_dumpregs(host);
ret = -EILSEQ;
}
return ret;
}
}
if (cmd->resp_type & MMC_RSP_PRESENT) {
if (cmd->resp_type & MMC_RSP_136) {
int i;
for (i = 0; i < 4; i++) {
cmd->response[3 - i] =
readl(host->ioaddr + SDRSP0 + i * 4);
}
} else {
cmd->response[0] = readl(host->ioaddr + SDRSP0);
}
}
/* Processed actual command. */
host->cmd = NULL;
if (host->data && host->data_complete)
ret = bcm2835_transfer_complete(host);
return ret;
}
static int bcm2835_check_cmd_error(struct bcm2835_host *host, u32 intmask)
{
int ret = -EINVAL;
if (!(intmask & SDHSTS_ERROR_MASK))
return 0;
if (!host->cmd)
return -EINVAL;
printf("sdhost_busy_irq: intmask %08x\n", intmask);
if (intmask & SDHSTS_CRC7_ERROR) {
ret = -EILSEQ;
} else if (intmask & (SDHSTS_CRC16_ERROR |
SDHSTS_FIFO_ERROR)) {
ret = -EILSEQ;
} else if (intmask & (SDHSTS_REW_TIME_OUT | SDHSTS_CMD_TIME_OUT)) {
ret = -ETIMEDOUT;
}
bcm2835_dumpregs(host);
return ret;
}
static int bcm2835_check_data_error(struct bcm2835_host *host, u32 intmask)
{
int ret = 0;
if (!host->data)
return 0;
if (intmask & (SDHSTS_CRC16_ERROR | SDHSTS_FIFO_ERROR))
ret = -EILSEQ;
if (intmask & SDHSTS_REW_TIME_OUT)
ret = -ETIMEDOUT;
if (ret)
printf("%s:%d %d\n", __func__, __LINE__, ret);
return ret;
}
static void bcm2835_busy_irq(struct bcm2835_host *host)
{
if (WARN_ON(!host->cmd)) {
bcm2835_dumpregs(host);
return;
}
if (WARN_ON(!host->use_busy)) {
bcm2835_dumpregs(host);
return;
}
host->use_busy = false;
bcm2835_finish_command(host);
}
static void bcm2835_data_irq(struct bcm2835_host *host, u32 intmask)
{
int ret;
/*
* There are no dedicated data/space available interrupt
* status bits, so it is necessary to use the single shared
* data/space available FIFO status bits. It is therefore not
* an error to get here when there is no data transfer in
* progress.
*/
if (!host->data)
return;
ret = bcm2835_check_data_error(host, intmask);
if (ret)
goto finished;
if (host->data->flags & MMC_DATA_WRITE) {
/* Use the block interrupt for writes after the first block */
host->hcfg &= ~(SDHCFG_DATA_IRPT_EN);
host->hcfg |= SDHCFG_BLOCK_IRPT_EN;
writel(host->hcfg, host->ioaddr + SDHCFG);
bcm2835_transfer_pio(host);
} else {
bcm2835_transfer_pio(host);
host->blocks--;
if ((host->blocks == 0))
goto finished;
}
return;
finished:
host->hcfg &= ~(SDHCFG_DATA_IRPT_EN | SDHCFG_BLOCK_IRPT_EN);
writel(host->hcfg, host->ioaddr + SDHCFG);
}
static void bcm2835_data_threaded_irq(struct bcm2835_host *host)
{
if (!host->data)
return;
if ((host->blocks == 0))
bcm2835_finish_data(host);
}
static void bcm2835_block_irq(struct bcm2835_host *host)
{
if (WARN_ON(!host->data)) {
bcm2835_dumpregs(host);
return;
}
WARN_ON(!host->blocks);
if ((--host->blocks == 0))
bcm2835_finish_data(host);
else
bcm2835_transfer_pio(host);
}
static irqreturn_t bcm2835_irq(int irq, void *dev_id)
{
irqreturn_t result = IRQ_NONE;
struct bcm2835_host *host = dev_id;
u32 intmask;
intmask = readl(host->ioaddr + SDHSTS);
writel(SDHSTS_BUSY_IRPT |
SDHSTS_BLOCK_IRPT |
SDHSTS_SDIO_IRPT |
SDHSTS_DATA_FLAG,
host->ioaddr + SDHSTS);
if (intmask & SDHSTS_BLOCK_IRPT) {
bcm2835_check_data_error(host, intmask);
host->irq_block = true;
result = IRQ_WAKE_THREAD;
}
if (intmask & SDHSTS_BUSY_IRPT) {
if (!bcm2835_check_cmd_error(host, intmask)) {
host->irq_busy = true;
result = IRQ_WAKE_THREAD;
} else {
result = IRQ_HANDLED;
}
}
/* There is no true data interrupt status bit, so it is
* necessary to qualify the data flag with the interrupt
* enable bit.
*/
if ((intmask & SDHSTS_DATA_FLAG) &&
(host->hcfg & SDHCFG_DATA_IRPT_EN)) {
bcm2835_data_irq(host, intmask);
host->irq_data = true;
result = IRQ_WAKE_THREAD;
}
return result;
}
static irqreturn_t bcm2835_threaded_irq(int irq, void *dev_id)
{
struct bcm2835_host *host = dev_id;
if (host->irq_block) {
host->irq_block = false;
bcm2835_block_irq(host);
}
if (host->irq_busy) {
host->irq_busy = false;
bcm2835_busy_irq(host);
}
if (host->irq_data) {
host->irq_data = false;
bcm2835_data_threaded_irq(host);
}
return IRQ_HANDLED;
}
static void bcm2835_irq_poll(struct bcm2835_host *host)
{
u32 intmask;
while (1) {
intmask = readl(host->ioaddr + SDHSTS);
if (intmask & (SDHSTS_BUSY_IRPT | SDHSTS_BLOCK_IRPT |
SDHSTS_SDIO_IRPT | SDHSTS_DATA_FLAG)) {
bcm2835_irq(0, host);
bcm2835_threaded_irq(0, host);
return;
}
}
}
static void bcm2835_set_clock(struct bcm2835_host *host, unsigned int clock)
{
int div;
/* The SDCDIV register has 11 bits, and holds (div - 2). But
* in data mode the max is 50MHz wihout a minimum, and only
* the bottom 3 bits are used. Since the switch over is
* automatic (unless we have marked the card as slow...),
* chosen values have to make sense in both modes. Ident mode
* must be 100-400KHz, so can range check the requested
* clock. CMD15 must be used to return to data mode, so this
* can be monitored.
*
* clock 250MHz -> 0->125MHz, 1->83.3MHz, 2->62.5MHz, 3->50.0MHz
* 4->41.7MHz, 5->35.7MHz, 6->31.3MHz, 7->27.8MHz
*
* 623->400KHz/27.8MHz
* reset value (507)->491159/50MHz
*
* BUT, the 3-bit clock divisor in data mode is too small if
* the core clock is higher than 250MHz, so instead use the
* SLOW_CARD configuration bit to force the use of the ident
* clock divisor at all times.
*/
if (clock < 100000) {
/* Can't stop the clock, but make it as slow as possible
* to show willing
*/
host->cdiv = SDCDIV_MAX_CDIV;
writel(host->cdiv, host->ioaddr + SDCDIV);
return;
}
div = host->max_clk / clock;
if (div < 2)
div = 2;
if ((host->max_clk / div) > clock)
div++;
div -= 2;
if (div > SDCDIV_MAX_CDIV)
div = SDCDIV_MAX_CDIV;
clock = host->max_clk / (div + 2);
host->mmc->clock = clock;
/* Calibrate some delays */
host->ns_per_fifo_word = (1000000000 / clock) *
((host->mmc->card_caps & MMC_MODE_4BIT) ? 8 : 32);
host->cdiv = div;
writel(host->cdiv, host->ioaddr + SDCDIV);
/* Set the timeout to 500ms */
writel(host->mmc->clock / 2, host->ioaddr + SDTOUT);
}
static inline int is_power_of_2(u64 x)
{
return !(x & (x - 1));
}
static int bcm2835_send_cmd(struct udevice *dev, struct mmc_cmd *cmd,
struct mmc_data *data)
{
struct bcm2835_host *host = dev_get_priv(dev);
u32 edm, fsm;
int ret = 0;
if (data && !is_power_of_2(data->blocksize)) {
printf("unsupported block size (%d bytes)\n", data->blocksize);
if (cmd)
return -EINVAL;
}
edm = readl(host->ioaddr + SDEDM);
fsm = edm & SDEDM_FSM_MASK;
if ((fsm != SDEDM_FSM_IDENTMODE) &&
(fsm != SDEDM_FSM_DATAMODE) &&
(cmd && cmd->cmdidx != MMC_CMD_STOP_TRANSMISSION)) {
printf("previous command (%d) not complete (EDM %08x)\n",
readl(host->ioaddr + SDCMD) & SDCMD_CMD_MASK, edm);
bcm2835_dumpregs(host);
if (cmd)
return -EILSEQ;
return 0;
}
if (cmd) {
ret = bcm2835_send_command(host, cmd, data);
if (!ret && !host->use_busy)
ret = bcm2835_finish_command(host);
}
/* Wait for completion of busy signal or data transfer */
while (host->use_busy || host->data)
bcm2835_irq_poll(host);
return ret;
}
static int bcm2835_set_ios(struct udevice *dev)
{
struct bcm2835_host *host = dev_get_priv(dev);
struct mmc *mmc = mmc_get_mmc_dev(dev);
if (!mmc->clock || mmc->clock != host->clock) {
bcm2835_set_clock(host, mmc->clock);
host->clock = mmc->clock;
}
/* set bus width */
host->hcfg &= ~SDHCFG_WIDE_EXT_BUS;
if (mmc->bus_width == 4)
host->hcfg |= SDHCFG_WIDE_EXT_BUS;
host->hcfg |= SDHCFG_WIDE_INT_BUS;
/* Disable clever clock switching, to cope with fast core clocks */
host->hcfg |= SDHCFG_SLOW_CARD;
writel(host->hcfg, host->ioaddr + SDHCFG);
return 0;
}
static void bcm2835_add_host(struct bcm2835_host *host)
{
struct mmc_config *cfg = &host->plat->cfg;
cfg->f_max = host->max_clk;
cfg->f_min = host->max_clk / SDCDIV_MAX_CDIV;
cfg->b_max = 65535;
dev_dbg(dev, "f_max %d, f_min %d\n",
cfg->f_max, cfg->f_min);
/* host controller capabilities */
cfg->host_caps = MMC_MODE_4BIT | MMC_MODE_HS | MMC_MODE_HS_52MHz;
/* report supported voltage ranges */
cfg->voltages = MMC_VDD_32_33 | MMC_VDD_33_34;
/* Set interrupt enables */
host->hcfg = SDHCFG_BUSY_IRPT_EN;
bcm2835_reset_internal(host);
}
static int bcm2835_probe(struct udevice *dev)
{
struct bcm2835_plat *plat = dev_get_platdata(dev);
struct bcm2835_host *host = dev_get_priv(dev);
struct mmc *mmc = mmc_get_mmc_dev(dev);
struct mmc_uclass_priv *upriv = dev_get_uclass_priv(dev);
host->dev = dev;
host->mmc = mmc;
host->plat = plat;
upriv->mmc = &plat->mmc;
plat->cfg.name = dev->name;
host->phys_addr = devfdt_get_addr(dev);
if (host->phys_addr == FDT_ADDR_T_NONE)
return -EINVAL;
host->ioaddr = devm_ioremap(dev, host->phys_addr, SZ_256);
if (!host->ioaddr)
return -ENOMEM;
host->max_clk = bcm2835_get_mmc_clock();
bcm2835_add_host(host);
dev_dbg(dev, "%s -> OK\n", __func__);
return 0;
}
static const struct udevice_id bcm2835_match[] = {
{ .compatible = "brcm,bcm2835-sdhost" },
{ }
};
static const struct dm_mmc_ops bcm2835_ops = {
.send_cmd = bcm2835_send_cmd,
.set_ios = bcm2835_set_ios,
};
static int bcm2835_bind(struct udevice *dev)
{
struct bcm2835_plat *plat = dev_get_platdata(dev);
return mmc_bind(dev, &plat->mmc, &plat->cfg);
}
U_BOOT_DRIVER(bcm2835_sdhost) = {
.name = "bcm2835-sdhost",
.id = UCLASS_MMC,
.of_match = bcm2835_match,
.bind = bcm2835_bind,
.probe = bcm2835_probe,
.priv_auto_alloc_size = sizeof(struct bcm2835_host),
.platdata_auto_alloc_size = sizeof(struct bcm2835_plat),
.ops = &bcm2835_ops,
};
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