Add function to support get voltage from device-tree.
If there are voltage-range specified in device-tree node, this function
will parse it and return the available voltage mask.
Signed-off-by: Haijun Zhang <haijun.zh...@freescale.com>
---
changes for v5:
- add binding spec for this device node
changes for v4:
- Add new parameter mask to return voltages.
.../devicetree/bindings/mmc/fsl-esdhc.txt | 4 ++
drivers/mmc/core/core.c | 44 ++++++++++++++++++++++
include/linux/mmc/core.h | 2 +
3 files changed, 50 insertions(+)
diff --git a/Documentation/devicetree/bindings/mmc/fsl-esdhc.txt
b/Documentation/devicetree/bindings/mmc/fsl-esdhc.txt
index bd9be0b..b7943f3 100644
--- a/Documentation/devicetree/bindings/mmc/fsl-esdhc.txt
+++ b/Documentation/devicetree/bindings/mmc/fsl-esdhc.txt
@@ -19,6 +19,9 @@ Optional properties:
"bus-width = <1>" property.
- sdhci,auto-cmd12: specifies that a controller can only handle auto
CMD12.
+ - voltage-ranges : two cells are required, first cell specifies minimum
+ slot voltage (mV), second cell specifies maximum slot voltage (mV).
+ Several ranges could be specified.
Example:
@@ -29,4 +32,5 @@ sdhci@2e000 {
interrupt-parent = <&ipic>;
/* Filled in by U-Boot */
clock-frequency = <0>;
+ voltage-ranges = <3300 3300>;
};
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 49a5bca..b9b9fb6 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -27,6 +27,7 @@
#include <linux/fault-inject.h>
#include <linux/random.h>
#include <linux/slab.h>
+#include <linux/of.h>
#include <linux/mmc/card.h>
#include <linux/mmc/host.h>
@@ -1196,6 +1197,49 @@ u32 mmc_vddrange_to_ocrmask(int vdd_min, int vdd_max)
}
EXPORT_SYMBOL(mmc_vddrange_to_ocrmask);
+#ifdef CONFIG_OF
+
+/**
+ * mmc_of_parse_voltage - return mask of supported voltages
+ * @np: The device node need to be parsed.
+ * @mask: mask of voltages available for MMC/SD/SDIO
+ *
+ * 1. Return zero on success.
+ * 2. Return negative errno: voltage-range is invalid.
+ */
+int mmc_of_parse_voltage(struct device_node *np, u32 *mask)
+{
+ const u32 *voltage_ranges;
+ int num_ranges, i;
+
+ voltage_ranges = of_get_property(np, "voltage-ranges", &num_ranges);
+ num_ranges = num_ranges / sizeof(*voltage_ranges) / 2;
+ if (!voltage_ranges || !num_ranges) {
+ pr_info("%s: voltage-ranges unspecified\n", np->full_name);
+ return -EINVAL;
+ }
+
+ for (i = 0; i < num_ranges; i++) {
+ const int j = i * 2;
+ u32 ocr_mask;
+
+ ocr_mask = mmc_vddrange_to_ocrmask(
+ be32_to_cpu(voltage_ranges[j]),
+ be32_to_cpu(voltage_ranges[j + 1]));
+ if (!ocr_mask) {
+ pr_err("%s: voltage-range #%d is invalid\n",
+ np->full_name, i);
+ return -EINVAL;
+ }
+ *mask |= ocr_mask;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(mmc_of_parse_voltage);
+
+#endif /* CONFIG_OF */
+
#ifdef CONFIG_REGULATOR
/**
diff --git a/include/linux/mmc/core.h b/include/linux/mmc/core.h
index 443243b..da51bec 100644
--- a/include/linux/mmc/core.h
+++ b/include/linux/mmc/core.h
@@ -208,6 +208,8 @@ static inline void mmc_claim_host(struct mmc_host *host)
__mmc_claim_host(host, NULL);
}
+struct device_node;
extern u32 mmc_vddrange_to_ocrmask(int vdd_min, int vdd_max);
+extern int mmc_of_parse_voltage(struct device_node *np, u32 *mask);
#endif /* LINUX_MMC_CORE_H */
--
1.8.0
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