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 V3:
- Correct the type of return value.
changes for v2:
- Update the parameters of function
drivers/mmc/core/core.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
include/linux/mmc/core.h | 2 ++
2 files changed, 47 insertions(+)
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 49a5bca..1b13c37 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -1196,6 +1196,51 @@ 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.
+ *
+ * 1. Return zero: voltage-ranges unspecified in device-tree
+ * 2. Return negative errno: voltage-range is invalid.
+ * 3. Return ocr_mask: a mask of voltages that parse from device-tree
+ * node that can be provided to MMC/SD/SDIO devices.
+ */
+int mmc_of_parse_voltage(struct device_node *np)
+{
+ const u32 *voltage_ranges;
+ int num_ranges, i;
+ int ocr_mask;
+
+ 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 0;
+ }
+
+ for (i = 0; i < num_ranges; i++) {
+ const int j = i * 2;
+ u32 mask;
+
+ mask = mmc_vddrange_to_ocrmask(
+ be32_to_cpu(voltage_ranges[j]),
+ be32_to_cpu(voltage_ranges[j + 1]));
+ if (!mask) {
+ pr_err("%s: voltage-range #%d is invalid\n",
+ np->full_name, i);
+ return -EINVAL;
+ }
+ ocr_mask |= mask;
+ }
+
+ return ocr_mask;
+}
+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..117f719 100644
--- a/include/linux/mmc/core.h
+++ b/include/linux/mmc/core.h
@@ -10,6 +10,7 @@
#include <linux/interrupt.h>
#include <linux/completion.h>
+#include <linux/of.h>
struct request;
struct mmc_data;
@@ -209,5 +210,6 @@ static inline void mmc_claim_host(struct mmc_host *host)
}
extern u32 mmc_vddrange_to_ocrmask(int vdd_min, int vdd_max);
+extern int mmc_of_parse_voltage(struct device_node *np);
#endif /* LINUX_MMC_CORE_H */
--
1.8.0
--
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