From: Venkat Gopalakrishnan <venkatg@xxxxxxxxxxxxxx>
SDCC core with minor version >= 0x42 requires a change in the reset
sequence for DLL tuning. Make necessary changes as needed.
Without this patch we see below errors on such SDHC controllers
sdhci_msm 7464900.sdhci: mmc0: DLL failed to LOCK
mmc0: tuning execution failed: -110
Signed-off-by: Venkat Gopalakrishnan <venkatg@xxxxxxxxxxxxxx>
Signed-off-by: Ritesh Harjani <riteshh@xxxxxxxxxxxxxx>
---
drivers/mmc/host/sdhci-msm.c | 45 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 45 insertions(+)
diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
index 8ef44a2a..9e08424 100644
--- a/drivers/mmc/host/sdhci-msm.c
+++ b/drivers/mmc/host/sdhci-msm.c
@@ -58,11 +58,17 @@
#define CORE_DLL_CONFIG 0x100
#define CORE_DLL_STATUS 0x108
+#define CORE_DLL_CONFIG_2 0x1b4
+#define CORE_FLL_CYCLE_CNT BIT(18)
+#define CORE_DLL_CLOCK_DISABLE BIT(21)
+
#define CORE_VENDOR_SPEC 0x10c
#define CORE_CLK_PWRSAVE BIT(1)
#define CORE_VENDOR_SPEC_CAPABILITIES0 0x11c
+#define TCXO_FREQ 19200000
+
#define CDR_SELEXT_SHIFT 20
#define CDR_SELEXT_MASK (0xf << CDR_SELEXT_SHIFT)
#define CMUX_SHIFT_PHASE_SHIFT 24
@@ -76,6 +82,7 @@ struct sdhci_msm_host {
struct clk *pclk; /* SDHC peripheral bus clock */
struct clk *bus_clk; /* SDHC bus voter clock */
struct mmc_host *mmc;
+ bool use_updated_dll_reset;
};
/* Platform specific tuning */
@@ -303,6 +310,8 @@ static inline void msm_cm_dll_set_freq(struct sdhci_host *host)
static int msm_init_cm_dll(struct sdhci_host *host)
{
struct mmc_host *mmc = host->mmc;
+ struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+ struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
int wait_cnt = 50;
unsigned long flags;
@@ -316,6 +325,15 @@ static int msm_init_cm_dll(struct sdhci_host *host)
writel_relaxed((readl_relaxed(host->ioaddr + CORE_VENDOR_SPEC)
& ~CORE_CLK_PWRSAVE), host->ioaddr + CORE_VENDOR_SPEC);
+ if (msm_host->use_updated_dll_reset) {
+ writel_relaxed((readl_relaxed(host->ioaddr + CORE_DLL_CONFIG)
+ & ~CORE_CK_OUT_EN),
+ host->ioaddr + CORE_DLL_CONFIG);
+ writel_relaxed((readl_relaxed(host->ioaddr + CORE_DLL_CONFIG_2)
+ | CORE_DLL_CLOCK_DISABLE),
+ host->ioaddr + CORE_DLL_CONFIG_2);
+ }
+
/* Write 1 to DLL_RST bit of DLL_CONFIG register */
writel_relaxed((readl_relaxed(host->ioaddr + CORE_DLL_CONFIG)
| CORE_DLL_RST), host->ioaddr + CORE_DLL_CONFIG);
@@ -325,6 +343,22 @@ static int msm_init_cm_dll(struct sdhci_host *host)
| CORE_DLL_PDN), host->ioaddr + CORE_DLL_CONFIG);
msm_cm_dll_set_freq(host);
+ if (msm_host->use_updated_dll_reset) {
+ u32 mclk_freq = 0;
+
+ if ((readl_relaxed(host->ioaddr + CORE_DLL_CONFIG_2)
+ & CORE_FLL_CYCLE_CNT))
+ mclk_freq = (u32) ((host->clock / TCXO_FREQ) * 8);
+ else
+ mclk_freq = (u32) ((host->clock / TCXO_FREQ) * 4);
+
+ writel_relaxed(((readl_relaxed(host->ioaddr + CORE_DLL_CONFIG_2)
+ & ~(0xFF << 10)) | (mclk_freq << 10)),
+ host->ioaddr + CORE_DLL_CONFIG_2);
+ /* wait for 5us before enabling DLL clock */
+ udelay(5);
+ }
+
/* Write 0 to DLL_RST bit of DLL_CONFIG register */
writel_relaxed((readl_relaxed(host->ioaddr + CORE_DLL_CONFIG)
& ~CORE_DLL_RST), host->ioaddr + CORE_DLL_CONFIG);
@@ -333,6 +367,14 @@ static int msm_init_cm_dll(struct sdhci_host *host)
writel_relaxed((readl_relaxed(host->ioaddr + CORE_DLL_CONFIG)
& ~CORE_DLL_PDN), host->ioaddr + CORE_DLL_CONFIG);
+ if (msm_host->use_updated_dll_reset) {
+ msm_cm_dll_set_freq(host);
+ /* Enable the DLL clock */
+ writel_relaxed((readl_relaxed(host->ioaddr + CORE_DLL_CONFIG_2)
+ & ~CORE_DLL_CLOCK_DISABLE),
+ host->ioaddr + CORE_DLL_CONFIG_2);
+ }
+
/* Set DLL_EN bit to 1. */
writel_relaxed((readl_relaxed(host->ioaddr + CORE_DLL_CONFIG)
| CORE_DLL_EN), host->ioaddr + CORE_DLL_CONFIG);
@@ -631,6 +673,9 @@ static int sdhci_msm_probe(struct platform_device *pdev)
dev_dbg(&pdev->dev, "MCI Version: 0x%08x, major: 0x%04x, minor: 0x%02x\n",
core_version, core_major, core_minor);
+ if ((core_major == 1) && (core_minor >= 0x42))
+ msm_host->use_updated_dll_reset = true;
+
/*
* Support for some capabilities is not advertised by newer
* controller versions and must be explicitly enabled.
--
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