linux-stable/drivers/mmc/core/sd_ops.c
Ulf Hansson ead49373d2 mmc: core: Initial support for SD express card/host
In the SD specification v7.10 the SD express card has been added. This new
type of removable SD card, can be managed via a PCIe/NVMe based interface,
while also allowing backwards compatibility towards the legacy SD
interface.

To keep the backwards compatibility, it's required to start the
initialization through the legacy SD interface. If it turns out that the
mmc host and the SD card, both supports the PCIe/NVMe interface, then a
switch should be allowed.

Therefore, let's introduce some basic support for this type of SD cards to
the mmc core. The mmc host, should set MMC_CAP2_SD_EXP if it supports this
interface and MMC_CAP2_SD_EXP_1_2V, if also 1.2V is supported, as to inform
the core about it.

To deal with the switch to the PCIe/NVMe interface, the mmc host is
required to implement a new host ops, ->init_sd_express(). Based on the
initial communication between the host and the card, host->ios.timing is
set to either MMC_TIMING_SD_EXP or MMC_TIMING_SD_EXP_1_2V, depending on if
1.2V is supported or not. In this way, the mmc host can check these values
in its ->init_sd_express() ops, to know how to proceed with the handover.

Note that, to manage card insert/removal, the mmc core sticks with using
the ->get_cd() callback, which means it's the host's responsibility to make
sure it provides valid data, even if the card may be managed by PCIe/NVMe
at the moment. As long as the card seems to be present, the mmc core keeps
the card powered on.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Rui Feng <rui_feng@realsil.com.cn>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/1603936636-3126-1-git-send-email-rui_feng@realsil.com.cn
2020-11-16 11:59:28 +01:00

390 lines
7.7 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* linux/drivers/mmc/core/sd_ops.h
*
* Copyright 2006-2007 Pierre Ossman
*/
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/export.h>
#include <linux/scatterlist.h>
#include <linux/mmc/host.h>
#include <linux/mmc/card.h>
#include <linux/mmc/mmc.h>
#include <linux/mmc/sd.h>
#include "core.h"
#include "sd_ops.h"
int mmc_app_cmd(struct mmc_host *host, struct mmc_card *card)
{
int err;
struct mmc_command cmd = {};
if (WARN_ON(card && card->host != host))
return -EINVAL;
cmd.opcode = MMC_APP_CMD;
if (card) {
cmd.arg = card->rca << 16;
cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_AC;
} else {
cmd.arg = 0;
cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_BCR;
}
err = mmc_wait_for_cmd(host, &cmd, 0);
if (err)
return err;
/* Check that card supported application commands */
if (!mmc_host_is_spi(host) && !(cmd.resp[0] & R1_APP_CMD))
return -EOPNOTSUPP;
return 0;
}
EXPORT_SYMBOL_GPL(mmc_app_cmd);
static int mmc_wait_for_app_cmd(struct mmc_host *host, struct mmc_card *card,
struct mmc_command *cmd)
{
struct mmc_request mrq = {};
int i, err = -EIO;
/*
* We have to resend MMC_APP_CMD for each attempt so
* we cannot use the retries field in mmc_command.
*/
for (i = 0; i <= MMC_CMD_RETRIES; i++) {
err = mmc_app_cmd(host, card);
if (err) {
/* no point in retrying; no APP commands allowed */
if (mmc_host_is_spi(host)) {
if (cmd->resp[0] & R1_SPI_ILLEGAL_COMMAND)
break;
}
continue;
}
memset(&mrq, 0, sizeof(struct mmc_request));
memset(cmd->resp, 0, sizeof(cmd->resp));
cmd->retries = 0;
mrq.cmd = cmd;
cmd->data = NULL;
mmc_wait_for_req(host, &mrq);
err = cmd->error;
if (!cmd->error)
break;
/* no point in retrying illegal APP commands */
if (mmc_host_is_spi(host)) {
if (cmd->resp[0] & R1_SPI_ILLEGAL_COMMAND)
break;
}
}
return err;
}
int mmc_app_set_bus_width(struct mmc_card *card, int width)
{
struct mmc_command cmd = {};
cmd.opcode = SD_APP_SET_BUS_WIDTH;
cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
switch (width) {
case MMC_BUS_WIDTH_1:
cmd.arg = SD_BUS_WIDTH_1;
break;
case MMC_BUS_WIDTH_4:
cmd.arg = SD_BUS_WIDTH_4;
break;
default:
return -EINVAL;
}
return mmc_wait_for_app_cmd(card->host, card, &cmd);
}
int mmc_send_app_op_cond(struct mmc_host *host, u32 ocr, u32 *rocr)
{
struct mmc_command cmd = {};
int i, err = 0;
cmd.opcode = SD_APP_OP_COND;
if (mmc_host_is_spi(host))
cmd.arg = ocr & (1 << 30); /* SPI only defines one bit */
else
cmd.arg = ocr;
cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R3 | MMC_CMD_BCR;
for (i = 100; i; i--) {
err = mmc_wait_for_app_cmd(host, NULL, &cmd);
if (err)
break;
/* if we're just probing, do a single pass */
if (ocr == 0)
break;
/* otherwise wait until reset completes */
if (mmc_host_is_spi(host)) {
if (!(cmd.resp[0] & R1_SPI_IDLE))
break;
} else {
if (cmd.resp[0] & MMC_CARD_BUSY)
break;
}
err = -ETIMEDOUT;
mmc_delay(10);
}
if (!i)
pr_err("%s: card never left busy state\n", mmc_hostname(host));
if (rocr && !mmc_host_is_spi(host))
*rocr = cmd.resp[0];
return err;
}
static int __mmc_send_if_cond(struct mmc_host *host, u32 ocr, u8 pcie_bits,
u32 *resp)
{
struct mmc_command cmd = {};
int err;
static const u8 test_pattern = 0xAA;
u8 result_pattern;
/*
* To support SD 2.0 cards, we must always invoke SD_SEND_IF_COND
* before SD_APP_OP_COND. This command will harmlessly fail for
* SD 1.0 cards.
*/
cmd.opcode = SD_SEND_IF_COND;
cmd.arg = ((ocr & 0xFF8000) != 0) << 8 | pcie_bits << 8 | test_pattern;
cmd.flags = MMC_RSP_SPI_R7 | MMC_RSP_R7 | MMC_CMD_BCR;
err = mmc_wait_for_cmd(host, &cmd, 0);
if (err)
return err;
if (mmc_host_is_spi(host))
result_pattern = cmd.resp[1] & 0xFF;
else
result_pattern = cmd.resp[0] & 0xFF;
if (result_pattern != test_pattern)
return -EIO;
if (resp)
*resp = cmd.resp[0];
return 0;
}
int mmc_send_if_cond(struct mmc_host *host, u32 ocr)
{
return __mmc_send_if_cond(host, ocr, 0, NULL);
}
int mmc_send_if_cond_pcie(struct mmc_host *host, u32 ocr)
{
u32 resp = 0;
u8 pcie_bits = 0;
int ret;
if (host->caps2 & MMC_CAP2_SD_EXP) {
/* Probe card for SD express support via PCIe. */
pcie_bits = 0x10;
if (host->caps2 & MMC_CAP2_SD_EXP_1_2V)
/* Probe also for 1.2V support. */
pcie_bits = 0x30;
}
ret = __mmc_send_if_cond(host, ocr, pcie_bits, &resp);
if (ret)
return 0;
/* Continue with the SD express init, if the card supports it. */
resp &= 0x3000;
if (pcie_bits && resp) {
if (resp == 0x3000)
host->ios.timing = MMC_TIMING_SD_EXP_1_2V;
else
host->ios.timing = MMC_TIMING_SD_EXP;
/*
* According to the spec the clock shall also be gated, but
* let's leave this to the host driver for more flexibility.
*/
return host->ops->init_sd_express(host, &host->ios);
}
return 0;
}
int mmc_send_relative_addr(struct mmc_host *host, unsigned int *rca)
{
int err;
struct mmc_command cmd = {};
cmd.opcode = SD_SEND_RELATIVE_ADDR;
cmd.arg = 0;
cmd.flags = MMC_RSP_R6 | MMC_CMD_BCR;
err = mmc_wait_for_cmd(host, &cmd, MMC_CMD_RETRIES);
if (err)
return err;
*rca = cmd.resp[0] >> 16;
return 0;
}
int mmc_app_send_scr(struct mmc_card *card)
{
int err;
struct mmc_request mrq = {};
struct mmc_command cmd = {};
struct mmc_data data = {};
struct scatterlist sg;
__be32 *scr;
/* NOTE: caller guarantees scr is heap-allocated */
err = mmc_app_cmd(card->host, card);
if (err)
return err;
/* dma onto stack is unsafe/nonportable, but callers to this
* routine normally provide temporary on-stack buffers ...
*/
scr = kmalloc(sizeof(card->raw_scr), GFP_KERNEL);
if (!scr)
return -ENOMEM;
mrq.cmd = &cmd;
mrq.data = &data;
cmd.opcode = SD_APP_SEND_SCR;
cmd.arg = 0;
cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;
data.blksz = 8;
data.blocks = 1;
data.flags = MMC_DATA_READ;
data.sg = &sg;
data.sg_len = 1;
sg_init_one(&sg, scr, 8);
mmc_set_data_timeout(&data, card);
mmc_wait_for_req(card->host, &mrq);
card->raw_scr[0] = be32_to_cpu(scr[0]);
card->raw_scr[1] = be32_to_cpu(scr[1]);
kfree(scr);
if (cmd.error)
return cmd.error;
if (data.error)
return data.error;
return 0;
}
int mmc_sd_switch(struct mmc_card *card, int mode, int group,
u8 value, u8 *resp)
{
struct mmc_request mrq = {};
struct mmc_command cmd = {};
struct mmc_data data = {};
struct scatterlist sg;
/* NOTE: caller guarantees resp is heap-allocated */
mode = !!mode;
value &= 0xF;
mrq.cmd = &cmd;
mrq.data = &data;
cmd.opcode = SD_SWITCH;
cmd.arg = mode << 31 | 0x00FFFFFF;
cmd.arg &= ~(0xF << (group * 4));
cmd.arg |= value << (group * 4);
cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;
data.blksz = 64;
data.blocks = 1;
data.flags = MMC_DATA_READ;
data.sg = &sg;
data.sg_len = 1;
sg_init_one(&sg, resp, 64);
mmc_set_data_timeout(&data, card);
mmc_wait_for_req(card->host, &mrq);
if (cmd.error)
return cmd.error;
if (data.error)
return data.error;
return 0;
}
int mmc_app_sd_status(struct mmc_card *card, void *ssr)
{
int err;
struct mmc_request mrq = {};
struct mmc_command cmd = {};
struct mmc_data data = {};
struct scatterlist sg;
/* NOTE: caller guarantees ssr is heap-allocated */
err = mmc_app_cmd(card->host, card);
if (err)
return err;
mrq.cmd = &cmd;
mrq.data = &data;
cmd.opcode = SD_APP_SD_STATUS;
cmd.arg = 0;
cmd.flags = MMC_RSP_SPI_R2 | MMC_RSP_R1 | MMC_CMD_ADTC;
data.blksz = 64;
data.blocks = 1;
data.flags = MMC_DATA_READ;
data.sg = &sg;
data.sg_len = 1;
sg_init_one(&sg, ssr, 64);
mmc_set_data_timeout(&data, card);
mmc_wait_for_req(card->host, &mrq);
if (cmd.error)
return cmd.error;
if (data.error)
return data.error;
return 0;
}