From: Victor Shih <victor.shih@xxxxxxxxxxxxxxxxxxx>
This is a sdhci version of mmc's uhs2_[enable|disable]_clk operations.
Updates in V8:
- Remove unnecessary include file.
- read_poll_timeout() to instead of read_poll_timeout_atomic()
in sdhci_uhs2_enable_clk().
- Put the comment on the end and put the lines in descending
line length in sdhci_uhs2_enable_clk().
- Modify return value in sdhci_uhs2_enable_clk().
Updates in V6:
- Remove unnecessary functions.
Signed-off-by: Ben Chuang <ben.chuang@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@xxxxxxxxxx>
Signed-off-by: Victor Shih <victor.shih@xxxxxxxxxxxxxxxxxxx>
---
drivers/mmc/host/sdhci-uhs2.c | 30 ++++++++++++++++++++++++++++++
1 file changed, 30 insertions(+)
diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
index 4c2a56629ab3..af1b0c5e48fd 100644
--- a/drivers/mmc/host/sdhci-uhs2.c
+++ b/drivers/mmc/host/sdhci-uhs2.c
@@ -329,6 +329,36 @@ static int sdhci_uhs2_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
return 0;
}
+static int sdhci_uhs2_disable_clk(struct mmc_host *mmc)
+{
+ struct sdhci_host *host = mmc_priv(mmc);
+ u16 clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
+
+ clk &= ~SDHCI_CLOCK_CARD_EN;
+ sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
+
+ return 0;
+}
+
+static int sdhci_uhs2_enable_clk(struct mmc_host *mmc)
+{
+ struct sdhci_host *host = mmc_priv(mmc);
+ u16 clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
+ int timeout_us = 20000; /* 20ms */
+ u32 val;
+
+ clk |= SDHCI_CLOCK_CARD_EN;
+ sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
+
+ if (read_poll_timeout(sdhci_readw, val, (val & SDHCI_CLOCK_INT_STABLE),
+ 10, timeout_us, true, host, SDHCI_CLOCK_CONTROL)) {
+ pr_err("%s: Internal clock never stabilised.\n", mmc_hostname(host->mmc));
+ sdhci_dumpregs(host);
+ return -EIO;
+ }
+ return 0;
+}
+
/*****************************************************************************\
* *
* Driver init/exit *
--
2.25.1
