[PATCH RFC 1/2] mmc: sdhci-msm: Add support to store supported vdd-io voltages

[Vijay Viswanath]

During probe check whether the vdd-io regulator of sdhc platform device
can support 1.8V and 3V and store this information as a capability of
platform device.

Signed-off-by: Vijay Viswanath <vviswana@xxxxxxxxxxxxxx>
---
 drivers/mmc/host/sdhci-msm.c | 38 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
index c283291..5c23e92 100644
--- a/drivers/mmc/host/sdhci-msm.c
+++ b/drivers/mmc/host/sdhci-msm.c
@@ -23,6 +23,7 @@
 #include <linux/iopoll.h>
 
 #include "sdhci-pltfm.h"
+#include <linux/regulator/consumer.h>
 
 #define CORE_MCI_VERSION		0x50
 #define CORE_VERSION_MAJOR_SHIFT	28
@@ -81,6 +82,9 @@
 #define CORE_HC_SELECT_IN_HS400	(6 << 19)
 #define CORE_HC_SELECT_IN_MASK	(7 << 19)
 
+#define CORE_3_0V_SUPPORT	(1 << 25)
+#define CORE_1_8V_SUPPORT	(1 << 26)
+
 #define CORE_CSR_CDC_CTLR_CFG0		0x130
 #define CORE_SW_TRIG_FULL_CALIB		BIT(16)
 #define CORE_HW_AUTOCAL_ENA		BIT(17)
@@ -148,6 +152,7 @@ struct sdhci_msm_host {
 	u32 curr_io_level;
 	wait_queue_head_t pwr_irq_wait;
 	bool pwr_irq_flag;
+	u32 caps_0;
 };
 
 static unsigned int msm_get_clock_rate_for_bus_mode(struct sdhci_host *host,
@@ -1313,6 +1318,35 @@ static void sdhci_msm_writeb(struct sdhci_host *host, u8 val, int reg)
 		sdhci_msm_check_power_status(host, req_type);
 }
 
+static int sdhci_msm_set_regulator_caps(struct sdhci_msm_host *msm_host)
+{
+	struct mmc_host *mmc = msm_host->mmc;
+	struct regulator *supply = mmc->supply.vqmmc;
+	int i, count;
+	u32 caps = 0, vdd_uV;
+
+	if (!IS_ERR(mmc->supply.vqmmc)) {
+		count = regulator_count_voltages(supply);
+		if (count < 0)
+			return count;
+		for (i = 0; i < count; i++) {
+			vdd_uV = regulator_list_voltage(supply, i);
+			if (vdd_uV <= 0)
+				continue;
+			if (vdd_uV > 2700000)
+				caps |= CORE_3_0V_SUPPORT;
+			if (vdd_uV < 1950000)
+				caps |= CORE_1_8V_SUPPORT;
+		}
+	}
+	msm_host->caps_0 |= caps;
+	pr_debug("%s: %s: supported caps: 0x%08x\n", mmc_hostname(mmc),
+			__func__, caps);
+
+	return 0;
+}
+
+
 static const struct of_device_id sdhci_msm_dt_match[] = {
 	{ .compatible = "qcom,sdhci-msm-v4" },
 	{},
@@ -1530,6 +1564,10 @@ static int sdhci_msm_probe(struct platform_device *pdev)
 	ret = sdhci_add_host(host);
 	if (ret)
 		goto pm_runtime_disable;
+	ret = sdhci_msm_set_regulator_caps(msm_host);
+	if (ret)
+		dev_err(&pdev->dev, "%s: Failed to set regulator caps: %d\n",
+				__func__, ret);
 
 	pm_runtime_mark_last_busy(&pdev->dev);
 	pm_runtime_put_autosuspend(&pdev->dev);
-- 
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