[PATCH v6 4/5] mmc: sdhci-msm: Add Device tree parsing logic for DLL settings

Ram Prakash Gupta
2025-12-15T12:00:37Z

From: Sachin Gupta <quic_sachgupt@quicinc.com>

This update introduces the capability to configure HS200
and HS400 DLL settings via the device tree and parsing it.

Signed-off-by: Sachin Gupta <quic_sachgupt@quicinc.com>
Signed-off-by: Ram Prakash Gupta <quic_rampraka@quicinc.com>
---
drivers/mmc/host/sdhci-msm.c | 41 ++++++++++++++++++++++++++++++++++++
1 file changed, 41 insertions(+)

diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
index dc79f828522b..1fcd92158bee 100644
--- a/drivers/mmc/host/sdhci-msm.c
+++ b/drivers/mmc/host/sdhci-msm.c
@@ -266,6 +266,19 @@ struct sdhci_msm_variant_info {
const struct sdhci_msm_offset *offset;
};

+/*
+ * DLL registers which needs be programmed with HSR settings.
+ * Add any new register only at the end and don't change the
+ * sequence.
+ */
+struct sdhci_msm_dll {
+ u32 dll_config;
+ u32 dll_config_2;
+ u32 dll_config_3;
+ u32 dll_usr_ctl;
+ u32 ddr_config;
+};
+
struct sdhci_msm_host {
struct platform_device *pdev;
void __iomem *core_mem; /* MSM SDCC mapped address */
@@ -274,6 +287,7 @@ struct sdhci_msm_host {
struct clk *xo_clk; /* TCXO clk needed for FLL feature of cm_dll*/
/* core, iface, cal and sleep clocks */
struct clk_bulk_data bulk_clks[4];
+ struct sdhci_msm_dll dll[2];
#ifdef CONFIG_MMC_CRYPTO
struct qcom_ice *ice;
#endif
@@ -302,6 +316,7 @@ struct sdhci_msm_host {
u32 dll_config;
u32 ddr_config;
bool vqmmc_enabled;
+ bool artanis_dll;
};

static const struct sdhci_msm_offset *sdhci_priv_msm_offset(struct sdhci_host *host)
@@ -2534,6 +2549,23 @@ static int sdhci_msm_gcc_reset(struct device *dev, struct sdhci_host *host)
return ret;
}

+#define DLL_SIZE 10
+static int sdhci_msm_dt_parse_dll_info(struct device *dev, struct sdhci_msm_host *msm_host)
+{
+ u32 *dll_table = &msm_host->dll[0].dll_config;
+ int ret;
+
+ msm_host->artanis_dll = false;
+
+ ret = of_property_read_variable_u32_array(dev->of_node,
+ "qcom,dll-presets",
+ dll_table, DLL_SIZE, DLL_SIZE);
+ if (ret == DLL_SIZE)
+ msm_host->artanis_dll = true;
+
+ return ret;
+}
+
static int sdhci_msm_probe(struct platform_device *pdev)
{
struct sdhci_host *host;
@@ -2580,6 +2612,15 @@ static int sdhci_msm_probe(struct platform_device *pdev)

msm_host->saved_tuning_phase = INVALID_TUNING_PHASE;

+ /*
+ * Parse HSR dll only when property is present in DT.
+ */
+ ret = sdhci_msm_dt_parse_dll_info(&pdev->dev, msm_host);
+ if (ret == -ENODATA || ret == -EOVERFLOW) {
+ dev_err(&pdev->dev, "Bad DLL in dt (%d)\n", ret);
+ return ret;
+ }
+
ret = sdhci_msm_gcc_reset(&pdev->dev, host);
if (ret)
return ret;
--
2.34.1