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

[Johan Rudholm <johan.rudholm@axis.com>]

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