mmc: sdhci: Add PLL Enable support to internal clock setup

The GL9750 and GL9755 chipsets, and possibly others, require PLL Enable
setup as part of the internal clock setup as described in 3.2.1 Internal
Clock Setup Sequence of SD Host Controller Simplified Specification
Version 4.20.

Signed-off-by: Ben Chuang <ben.chuang@genesyslogic.com.tw>
Co-developed-by: Michael K Johnson <johnsonm@danlj.org>
Signed-off-by: Michael K Johnson <johnsonm@danlj.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

2 files changed, 24 insertions, 0 deletions

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 40de56d6da0b..de833b1eadb9 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1653,6 +1653,29 @@ void sdhci_enable_clk(struct sdhci_host *host, u16 clk)
                 udelay(10);
         }
 
+        if (host->version >= SDHCI_SPEC_410 && host->v4_mode) {
+                clk |= SDHCI_CLOCK_PLL_EN;
+                clk &= ~SDHCI_CLOCK_INT_STABLE;
+                sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
+
+                /* Wait max 150 ms */
+                timeout = ktime_add_ms(ktime_get(), 150);
+                while (1) {
+                        bool timedout = ktime_after(ktime_get(), timeout);
+
+                        clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
+                        if (clk & SDHCI_CLOCK_INT_STABLE)
+                                break;
+                        if (timedout) {
+                                pr_err("%s: PLL clock never stabilised.\n",
+                                       mmc_hostname(host->mmc));
+                                sdhci_dumpregs(host);
+                                return;
+                        }
+                        udelay(10);
+                }
+        }
+
         clk |= SDHCI_CLOCK_CARD_EN;
         sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
 }
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 902f855efe8f..929310e869a3 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -114,6 +114,7 @@
 #define  SDHCI_DIV_HI_MASK      0x300
 #define  SDHCI_PROG_CLOCK_MODE  0x0020
 #define  SDHCI_CLOCK_CARD_EN    0x0004
+#define  SDHCI_CLOCK_PLL_EN     0x0008
 #define  SDHCI_CLOCK_INT_STABLE 0x0002
 #define  SDHCI_CLOCK_INT_EN     0x0001