[PATCH V20 13/22] mmc: sdhci-uhs2: add set_timeout()

Victor Shih
2024-09-05T10:21:02Z

This is a UHS-II version of sdhci's set_timeout() operation.
Use sdhci_uhs2_set_timeout() to set and calculate the timeout time.

Signed-off-by: Ben Chuang <ben.chuang@genesyslogic.com.tw>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Victor Shih <victor.shih@genesyslogic.com.tw>
---

Updates in V14:
- Use mmc_card_uhs2() to stead sdhci_uhs2_mode() in the
sdhci_uhs2_set_timeout().

Updates in V13:
- Modify comment message.

Updates in V8:
- Initialization be combined with declaration and realigned
in sdhci_calc_timeout_uhs2().
- Forward declare struct mmc_command in sdhci_uhs2.h.

Updates in V6:
- Use GENMASK() and FIELD_PREP() in some case.
- Use sdhci_uhs2_mode() to simplify code.
- Remove unnecessary functions.

---

drivers/mmc/host/sdhci-uhs2.c | 72 +++++++++++++++++++++++++++++++++++
drivers/mmc/host/sdhci-uhs2.h | 2 +
2 files changed, 74 insertions(+)

diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
index 0cfe9a3f91f7..8bd2baa79d76 100644
--- a/drivers/mmc/host/sdhci-uhs2.c
+++ b/drivers/mmc/host/sdhci-uhs2.c
@@ -13,6 +13,7 @@
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/iopoll.h>
+#include <linux/bitfield.h>

#include "sdhci.h"
#include "sdhci-uhs2.h"
@@ -135,6 +136,77 @@ void sdhci_uhs2_set_power(struct sdhci_host *host, unsigned char mode, unsigned
}
EXPORT_SYMBOL_GPL(sdhci_uhs2_set_power);

+static u8 sdhci_calc_timeout_uhs2(struct sdhci_host *host, u8 *cmd_res, u8 *dead_lock)
+{
+ /* timeout in us */
+ unsigned int dead_lock_timeout = 1 * 1000 * 1000;
+ unsigned int cmd_res_timeout = 5 * 1000;
+ unsigned int current_timeout;
+ u8 count;
+
+ /*
+ * Figure out needed cycles.
+ * We do this in steps in order to fit inside a 32 bit int.
+ * The first step is the minimum timeout, which will have a
+ * minimum resolution of 6 bits:
+ * (1) 2^13*1000 > 2^22,
+ * (2) host->timeout_clk < 2^16
+ * =>
+ * (1) / (2) > 2^6
+ */
+ count = 0;
+ current_timeout = (1 << 13) * 1000 / host->timeout_clk;
+ while (current_timeout < cmd_res_timeout) {
+ count++;
+ current_timeout <<= 1;
+ if (count >= 0xF)
+ break;
+ }
+
+ if (count >= 0xF) {
+ DBG("%s: Too large timeout 0x%x requested for CMD_RES!\n",
+ mmc_hostname(host->mmc), count);
+ count = 0xE;
+ }
+ *cmd_res = count;
+
+ count = 0;
+ current_timeout = (1 << 13) * 1000 / host->timeout_clk;
+ while (current_timeout < dead_lock_timeout) {
+ count++;
+ current_timeout <<= 1;
+ if (count >= 0xF)
+ break;
+ }
+
+ if (count >= 0xF) {
+ DBG("%s: Too large timeout 0x%x requested for DEADLOCK!\n",
+ mmc_hostname(host->mmc), count);
+ count = 0xE;
+ }
+ *dead_lock = count;
+
+ return count;
+}
+
+static void __sdhci_uhs2_set_timeout(struct sdhci_host *host)
+{
+ u8 cmd_res, dead_lock;
+
+ sdhci_calc_timeout_uhs2(host, &cmd_res, &dead_lock);
+ cmd_res |= FIELD_PREP(SDHCI_UHS2_TIMER_CTRL_DEADLOCK_MASK, dead_lock);
+ sdhci_writeb(host, cmd_res, SDHCI_UHS2_TIMER_CTRL);
+}
+
+void sdhci_uhs2_set_timeout(struct sdhci_host *host, struct mmc_command *cmd)
+{
+ __sdhci_set_timeout(host, cmd);
+
+ if (mmc_card_uhs2(host->mmc))
+ __sdhci_uhs2_set_timeout(host);
+}
+EXPORT_SYMBOL_GPL(sdhci_uhs2_set_timeout);
+
/*****************************************************************************\
* *
* Driver init/exit *
diff --git a/drivers/mmc/host/sdhci-uhs2.h b/drivers/mmc/host/sdhci-uhs2.h
index 3efa8dd690bf..9bd3f610cf8c 100644
--- a/drivers/mmc/host/sdhci-uhs2.h
+++ b/drivers/mmc/host/sdhci-uhs2.h
@@ -175,9 +175,11 @@
#define SDHCI_UHS2_VENDOR_PTR 0xE8

struct sdhci_host;
+struct mmc_command;

void sdhci_uhs2_dump_regs(struct sdhci_host *host);
void sdhci_uhs2_reset(struct sdhci_host *host, u16 mask);
void sdhci_uhs2_set_power(struct sdhci_host *host, unsigned char mode, unsigned short vdd);
+void sdhci_uhs2_set_timeout(struct sdhci_host *host, struct mmc_command *cmd);

#endif /* __SDHCI_UHS2_H */
--
2.25.1