diff options
| author | Haijun Zhang <Haijun.Zhang@freescale.com> | 2013-08-26 09:19:22 +0800 |
|---|---|---|
| committer | Chris Ball <cjb@laptop.org> | 2013-08-26 11:31:40 -0400 |
| commit | 6e9e318b304fd7373a0754805a76a02ddbc69a41 (patch) | |
| tree | 43c05fa267bf780264a154e7145fe29aa0ad6c77 /drivers | |
| parent | bcf24e1daa94f4c52ef7a3f657e43cc6bc50d46b (diff) | |
mmc: core: parse voltage from device-tree
Add function to support getting voltage from device-tree.
If voltage-range is specified in device-tree node, this function
will parse it and return the available voltage mask.
Signed-off-by: Haijun Zhang <haijun.zhang@freescale.com>
Acked-by: Anton Vorontsov <anton@enomsg.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/mmc/core/core.c | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index 49a5bca418b..b9b9fb6e449 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 /** |