[PATCH V15 11/22] mmc: sdhci-uhs2: add reset function function
From: Victor Shih
Date: Mon Apr 22 2024 - 06:41:36 EST
From: Victor Shih <victor.shih@xxxxxxxxxxxxxxxxxxx>
Sdhci_uhs2_reset() does a UHS-II specific reset operation.
Signed-off-by: Ben Chuang <ben.chuang@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@xxxxxxxxxx>
Signed-off-by: Victor Shih <victor.shih@xxxxxxxxxxxxxxxxxxx>
---
Updates in V15:
- Refer the SD Host Controller Standard Specification Section 3.10
to add reset command data mechanism.
Updates in V14:
- Since mmc_card_uhs2() is the same as sdhci_uhs2_mode(), so drop
sdhci_uhs2_mode() and use mmc_card_uhs2() instead of sdhci_uhs2_mode().
Updates in V13:
- Use ios timing to stead MMC_UHS2_SUPPORT for indicate the UHS2 mode.
Updates in V8:
- Adjust the position of matching brackets.
Updates in V6:
- Remove unnecessary functions and simplify code.
---
drivers/mmc/host/sdhci-uhs2.c | 57 +++++++++++++++++++++++++++++++++++
drivers/mmc/host/sdhci-uhs2.h | 1 +
drivers/mmc/host/sdhci.c | 3 +-
drivers/mmc/host/sdhci.h | 1 +
4 files changed, 61 insertions(+), 1 deletion(-)
diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
index 9cb0f1b2a37d..7652158ea151 100644
--- a/drivers/mmc/host/sdhci-uhs2.c
+++ b/drivers/mmc/host/sdhci-uhs2.c
@@ -10,7 +10,9 @@
* Author: AKASHI Takahiro <takahiro.akashi@xxxxxxxxxx>
*/
+#include <linux/delay.h>
#include <linux/module.h>
+#include <linux/iopoll.h>
#include "sdhci.h"
#include "sdhci-uhs2.h"
@@ -21,6 +23,8 @@
#define SDHCI_UHS2_DUMP(f, x...) \
pr_err("%s: " DRIVER_NAME ": " f, mmc_hostname(host->mmc), ## x)
+#define UHS2_RESET_TIMEOUT_100MS 100000
+
void sdhci_uhs2_dump_regs(struct sdhci_host *host)
{
if (!(mmc_card_uhs2(host->mmc)))
@@ -49,6 +53,57 @@ void sdhci_uhs2_dump_regs(struct sdhci_host *host)
}
EXPORT_SYMBOL_GPL(sdhci_uhs2_dump_regs);
+/*****************************************************************************\
+ * *
+ * Low level functions *
+ * *
+\*****************************************************************************/
+
+/**
+ * sdhci_uhs2_reset - invoke SW reset
+ * @host: SDHCI host
+ * @mask: Control mask
+ *
+ * Invoke SW reset, depending on a bit in @mask and wait for completion.
+ */
+void sdhci_uhs2_reset(struct sdhci_host *host, u16 mask)
+{
+ u32 val;
+
+ sdhci_writew(host, mask, SDHCI_UHS2_SW_RESET);
+
+ if (mask & SDHCI_UHS2_SW_RESET_FULL)
+ host->clock = 0;
+
+ /* hw clears the bit when it's done */
+ if (read_poll_timeout_atomic(sdhci_readw, val, !(val & mask), 10,
+ UHS2_RESET_TIMEOUT_100MS, true, host, SDHCI_UHS2_SW_RESET)) {
+ pr_warn("%s: %s: Reset 0x%x never completed. %s: clean reset bit.\n", __func__,
+ mmc_hostname(host->mmc), (int)mask, mmc_hostname(host->mmc));
+ sdhci_writeb(host, 0, SDHCI_UHS2_SW_RESET);
+ return;
+ }
+}
+EXPORT_SYMBOL_GPL(sdhci_uhs2_reset);
+
+static void sdhci_uhs2_reset_cmd_data(struct mmc_host *mmc)
+{
+ struct sdhci_host *host = mmc_priv(mmc);
+
+ sdhci_do_reset(host, SDHCI_RESET_CMD | SDHCI_RESET_DATA);
+
+ if (host->mmc->ios.timing == MMC_TIMING_UHS2_SPEED_A ||
+ host->mmc->ios.timing == MMC_TIMING_UHS2_SPEED_A_HD ||
+ host->mmc->ios.timing == MMC_TIMING_UHS2_SPEED_B ||
+ host->mmc->ios.timing == MMC_TIMING_UHS2_SPEED_B_HD) {
+ sdhci_uhs2_reset(host, SDHCI_UHS2_SW_RESET_SD);
+
+ sdhci_writel(host, host->ier, SDHCI_INT_ENABLE);
+ sdhci_writel(host, host->ier, SDHCI_SIGNAL_ENABLE);
+ sdhci_uhs2_clear_set_irqs(host, SDHCI_INT_ALL_MASK, SDHCI_UHS2_INT_ERROR_MASK);
+ }
+}
+
/*****************************************************************************\
* *
* Driver init/exit *
@@ -57,6 +112,8 @@ EXPORT_SYMBOL_GPL(sdhci_uhs2_dump_regs);
static int sdhci_uhs2_host_ops_init(struct sdhci_host *host)
{
+ host->mmc_host_ops.uhs2_reset_cmd_data = sdhci_uhs2_reset_cmd_data;
+
return 0;
}
diff --git a/drivers/mmc/host/sdhci-uhs2.h b/drivers/mmc/host/sdhci-uhs2.h
index 2bfe18d29bca..caaf9fba4975 100644
--- a/drivers/mmc/host/sdhci-uhs2.h
+++ b/drivers/mmc/host/sdhci-uhs2.h
@@ -177,5 +177,6 @@
struct sdhci_host;
void sdhci_uhs2_dump_regs(struct sdhci_host *host);
+void sdhci_uhs2_reset(struct sdhci_host *host, u16 mask);
#endif /* __SDHCI_UHS2_H */
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 27ea5b875c29..f9db861853b4 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -236,7 +236,7 @@ void sdhci_reset(struct sdhci_host *host, u8 mask)
}
EXPORT_SYMBOL_GPL(sdhci_reset);
-static bool sdhci_do_reset(struct sdhci_host *host, u8 mask)
+bool sdhci_do_reset(struct sdhci_host *host, u8 mask)
{
if (host->quirks & SDHCI_QUIRK_NO_CARD_NO_RESET) {
struct mmc_host *mmc = host->mmc;
@@ -249,6 +249,7 @@ static bool sdhci_do_reset(struct sdhci_host *host, u8 mask)
return true;
}
+EXPORT_SYMBOL_GPL(sdhci_do_reset);
static void sdhci_reset_for_all(struct sdhci_host *host)
{
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 782c399fae15..47962cebee22 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -844,6 +844,7 @@ void sdhci_request(struct mmc_host *mmc, struct mmc_request *mrq);
int sdhci_request_atomic(struct mmc_host *mmc, struct mmc_request *mrq);
void sdhci_set_bus_width(struct sdhci_host *host, int width);
void sdhci_reset(struct sdhci_host *host, u8 mask);
+bool sdhci_do_reset(struct sdhci_host *host, u8 mask);
void sdhci_set_uhs_signaling(struct sdhci_host *host, unsigned timing);
int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode);
int __sdhci_execute_tuning(struct sdhci_host *host, u32 opcode);
--
2.25.1