[PATCH v6 1/2] mmc: core: refactor the hw_reset routines

Johan Rudholm
2015-01-09T11:08:43Z

Move the (e)MMC specific hw_reset code from core.c into mmc.c Call the
code from the new bus_ops member hw_reset. This also allows for adding
a SD card specific reset procedure.

Always check if the card is alive after a successful reset. This allows
us to remove mmc_hw_reset_check(), leaving mmc_hw_reset() as the only
card reset interface. This also informs any callers, for instance the
block layer, if a reset was sucessful or not.

Signed-off-by: Johan Rudholm <johanru@axis.com>
---
drivers/mmc/card/mmc_test.c | 18 ++++-------
drivers/mmc/core/core.c | 70 +++++++++++++++----------------------------
drivers/mmc/core/core.h | 1 +
drivers/mmc/core/mmc.c | 32 +++++++++++++++++++
include/linux/mmc/core.h | 1 -
5 files changed, 64 insertions(+), 58 deletions(-)

diff --git a/drivers/mmc/card/mmc_test.c b/drivers/mmc/card/mmc_test.c
index 0a7430f..7dac469 100644
--- a/drivers/mmc/card/mmc_test.c
+++ b/drivers/mmc/card/mmc_test.c
@@ -2342,20 +2342,16 @@ static int mmc_test_hw_reset(struct mmc_test_card *test)
struct mmc_host *host = card->host;
int err;

- err = mmc_hw_reset_check(host);
+ if (!mmc_card_mmc(card) || !mmc_can_reset(card))
+ return RESULT_UNSUP_CARD;
+
+ err = mmc_hw_reset(host);
if (!err)
return RESULT_OK;
+ else if (err == -EOPNOTSUPP)
+ return RESULT_UNSUP_HOST;

- if (err == -ENOSYS)
- return RESULT_FAIL;
-
- if (err != -EOPNOTSUPP)
- return err;
-
- if (!mmc_can_reset(card))
- return RESULT_UNSUP_CARD;
-
- return RESULT_UNSUP_HOST;
+ return RESULT_FAIL;
}

static const struct mmc_test_case mmc_test_cases[] = {
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index d3bfbdf..8598287 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -2273,67 +2273,45 @@ static void mmc_hw_reset_for_init(struct mmc_host *host)
mmc_host_clk_release(host);
}

-int mmc_can_reset(struct mmc_card *card)
-{
- u8 rst_n_function;
-
- if (!mmc_card_mmc(card))
- return 0;
- rst_n_function = card->ext_csd.rst_n_function;
- if ((rst_n_function & EXT_CSD_RST_N_EN_MASK) != EXT_CSD_RST_N_ENABLED)
- return 0;
- return 1;
-}
-EXPORT_SYMBOL(mmc_can_reset);
-
-static int mmc_do_hw_reset(struct mmc_host *host, int check)
+int mmc_hw_reset(struct mmc_host *host)
{
- struct mmc_card *card = host->card;
-
- if (!(host->caps & MMC_CAP_HW_RESET) || !host->ops->hw_reset)
- return -EOPNOTSUPP;
+ int ret = 0;
+ int card_alive = 0;
+ u32 status;

- if (!card)
+ if (!host->card)
return -EINVAL;

- if (!mmc_can_reset(card))
- return -EOPNOTSUPP;
-
- mmc_host_clk_hold(host);
- mmc_set_clock(host, host->f_init);
+ mmc_bus_get(host);
+ if (!host->bus_ops || host->bus_dead || !host->bus_ops->hw_reset) {
+ ret = -EOPNOTSUPP;
+ goto out;
+ }

- host->ops->hw_reset(host);
+ ret = host->bus_ops->hw_reset(host);
+ if (ret)
+ goto out;

/* If the reset has happened, then a status command will fail */
- if (check) {
- u32 status;
+ if (!mmc_send_status(host->card, &status))
+ card_alive = 1;

- if (!mmc_send_status(card, &status)) {
- mmc_host_clk_release(host);
- return -ENOSYS;
- }
- }
+ pr_warn("%s: tried to reset card (%s)\n", mmc_hostname(host),
+ card_alive ? "failed" : "ok");

/* Set initial state and call mmc_set_ios */
mmc_set_initial_state(host);
+ ret = host->bus_ops->power_restore(host);

- mmc_host_clk_release(host);
-
- return host->bus_ops->power_restore(host);
-}
-
-int mmc_hw_reset(struct mmc_host *host)
-{
- return mmc_do_hw_reset(host, 0);
+out:
+ mmc_bus_put(host);
+ if (card_alive)
+ return -ENOSYS;
+ else
+ return ret;
}
EXPORT_SYMBOL(mmc_hw_reset);

-int mmc_hw_reset_check(struct mmc_host *host)
-{
- return mmc_do_hw_reset(host, 1);
-}
-EXPORT_SYMBOL(mmc_hw_reset_check);
-
static int mmc_rescan_try_freq(struct mmc_host *host, unsigned freq)
{
host->f_init = freq;
diff --git a/drivers/mmc/core/core.h b/drivers/mmc/core/core.h
index b528c0e..4d1ee8a 100644
--- a/drivers/mmc/core/core.h
+++ b/drivers/mmc/core/core.h
@@ -27,6 +27,7 @@ struct mmc_bus_ops {
int (*power_restore)(struct mmc_host *);
int (*alive)(struct mmc_host *);
int (*shutdown)(struct mmc_host *);
+ int (*hw_reset)(struct mmc_host *);
};

void mmc_attach_bus(struct mmc_host *host, const struct mmc_bus_ops *ops);
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 0b8ec87..f64a53e 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -1795,6 +1795,37 @@ static int mmc_power_restore(struct mmc_host *host)
return ret;
}

+int mmc_can_reset(struct mmc_card *card)
+{
+ u8 rst_n_function;
+
+ rst_n_function = card->ext_csd.rst_n_function;
+ if ((rst_n_function & EXT_CSD_RST_N_EN_MASK) != EXT_CSD_RST_N_ENABLED)
+ return 0;
+ return 1;
+}
+EXPORT_SYMBOL(mmc_can_reset);
+
+static int mmc_mmc_hw_reset(struct mmc_host *host)
+{
+ struct mmc_card *card = host->card;
+
+ if (!(host->caps & MMC_CAP_HW_RESET) || !host->ops->hw_reset)
+ return -EOPNOTSUPP;
+
+ if (!mmc_can_reset(card))
+ return -EOPNOTSUPP;
+
+ mmc_host_clk_hold(host);
+ mmc_set_clock(host, host->f_init);
+
+ host->ops->hw_reset(host);
+
+ mmc_host_clk_release(host);
+
+ return 0;
+}
+
static const struct mmc_bus_ops mmc_ops = {
.remove = mmc_remove,
.detect = mmc_detect,
@@ -1805,6 +1836,7 @@ static const struct mmc_bus_ops mmc_ops = {
.power_restore = mmc_power_restore,
.alive = mmc_alive,
.shutdown = mmc_shutdown,
+ .hw_reset = mmc_mmc_hw_reset,
};

/*
diff --git a/include/linux/mmc/core.h b/include/linux/mmc/core.h
index cb2b040..160448f 100644
--- a/include/linux/mmc/core.h
+++ b/include/linux/mmc/core.h
@@ -182,7 +182,6 @@ extern int mmc_set_blocklen(struct mmc_card *card, unsigned int blocklen);
extern int mmc_set_blockcount(struct mmc_card *card, unsigned int blockcount,
bool is_rel_write);
extern int mmc_hw_reset(struct mmc_host *host);
-extern int mmc_hw_reset_check(struct mmc_host *host);
extern int mmc_can_reset(struct mmc_card *card);

extern void mmc_set_data_timeout(struct mmc_data *, const struct mmc_card *);
--
1.7.2.5