diff options
Diffstat (limited to 'drivers/rtc/rtc-r7301.c')
| -rw-r--r-- | drivers/rtc/rtc-r7301.c | 35 |
1 files changed, 33 insertions, 2 deletions
diff --git a/drivers/rtc/rtc-r7301.c b/drivers/rtc/rtc-r7301.c index 5dbaeb7af6..ef913cf859 100644 --- a/drivers/rtc/rtc-r7301.c +++ b/drivers/rtc/rtc-r7301.c @@ -14,6 +14,7 @@ #include <linux/module.h> #include <linux/mod_devicetable.h> #include <linux/delay.h> +#include <linux/property.h> #include <linux/regmap.h> #include <linux/platform_device.h> #include <linux/rtc.h> @@ -55,12 +56,23 @@ struct rtc7301_priv { u8 bank; }; -static const struct regmap_config rtc7301_regmap_config = { +/* + * When the device is memory-mapped, some platforms pack the registers into + * 32-bit access using the lower 8 bits at each 4-byte stride, while others + * expose them as simply consecutive bytes. + */ +static const struct regmap_config rtc7301_regmap_32_config = { .reg_bits = 32, .val_bits = 8, .reg_stride = 4, }; +static const struct regmap_config rtc7301_regmap_8_config = { + .reg_bits = 8, + .val_bits = 8, + .reg_stride = 1, +}; + static u8 rtc7301_read(struct rtc7301_priv *priv, unsigned int reg) { int reg_stride = regmap_get_reg_stride(priv->regmap); @@ -356,7 +368,9 @@ static int __init rtc7301_rtc_probe(struct platform_device *dev) void __iomem *regs; struct rtc7301_priv *priv; struct rtc_device *rtc; + static const struct regmap_config *mapconf; int ret; + u32 val; priv = devm_kzalloc(&dev->dev, sizeof(*priv), GFP_KERNEL); if (!priv) @@ -366,8 +380,25 @@ static int __init rtc7301_rtc_probe(struct platform_device *dev) if (IS_ERR(regs)) return PTR_ERR(regs); + ret = device_property_read_u32(&dev->dev, "reg-io-width", &val); + if (ret) + /* Default to 32bit accesses */ + val = 4; + + switch (val) { + case 1: + mapconf = &rtc7301_regmap_8_config; + break; + case 4: + mapconf = &rtc7301_regmap_32_config; + break; + default: + dev_err(&dev->dev, "invalid reg-io-width %d\n", val); + return -EINVAL; + } + priv->regmap = devm_regmap_init_mmio(&dev->dev, regs, - &rtc7301_regmap_config); + mapconf); if (IS_ERR(priv->regmap)) return PTR_ERR(priv->regmap); |