regmap: Add support for device specific write and read flag masks.

Some buses like SPI have no standard notation of read or write operations.
The general scheme here is to set or clear specific bits in the register
address to indicate whether the operation is a read or write. We already
support having a read flag mask per bus, but as there is no standard
the bits which need to be set or cleared differ between devices and vendors,
thus we need a mechanism to specify them per device.

This patch adds two new entries to the regmap_config struct, read_flag_mask and
write_flag_mask. These will be or'ed onto the top byte when doing a read or
write operation. If both masks are empty the device will fallback to the
regmap_bus masks.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h
index 5ab3fefa4b05dbf0eac29c8b006ee1496017e88e..7e14d5a6f53e6a990c8411838212b5abe1925b5f 100644 (file)
--- a/drivers/base/regmap/internal.h
+++ b/drivers/base/regmap/internal.h
@@ -46,6 +46,9 @@ struct regmap {
        bool (*readable_reg)(struct device *dev, unsigned int reg);
        bool (*volatile_reg)(struct device *dev, unsigned int reg);
        bool (*precious_reg)(struct device *dev, unsigned int reg);
+
+       u8 read_flag_mask;
+       u8 write_flag_mask;
 };
 
 bool regmap_writeable(struct regmap *map, unsigned int reg);

diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index 86b1847761998bd45ee5ce39994d87803daf7b09..e7adfe70e42506dd0d92a421b30746ec26d126ed 100644 (file)
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -147,6 +147,13 @@ struct regmap *regmap_init(struct device *dev,
        map->volatile_reg = config->volatile_reg;
        map->precious_reg = config->precious_reg;
 
+       if (config->read_flag_mask || config->write_flag_mask) {
+               map->read_flag_mask = config->read_flag_mask;
+               map->write_flag_mask = config->write_flag_mask;
+       } else {
+               map->read_flag_mask = bus->read_flag_mask;
+       }
+
        switch (config->reg_bits) {
        case 4:
                switch (config->val_bits) {
@@ -226,6 +233,7 @@ EXPORT_SYMBOL_GPL(regmap_exit);
 static int _regmap_raw_write(struct regmap *map, unsigned int reg,
                             const void *val, size_t val_len)
 {
+       u8 *u8 = map->work_buf;
        void *buf;
        int ret = -ENOTSUPP;
        size_t len;
@@ -239,6 +247,8 @@ static int _regmap_raw_write(struct regmap *map, unsigned int reg,
 
        map->format.format_reg(map->work_buf, reg);
 
+       u8[0] |= map->write_flag_mask;
+
        trace_regmap_hw_write_start(map->dev, reg,
                                    val_len / map->format.val_bytes);
 
@@ -366,13 +376,12 @@ static int _regmap_raw_read(struct regmap *map, unsigned int reg, void *val,
        map->format.format_reg(map->work_buf, reg);
 
        /*
-        * Some buses flag reads by setting the high bits in the
+        * Some buses or devices flag reads by setting the high bits in the
         * register addresss; since it's always the high bits for all
         * current formats we can do this here rather than in
         * formatting.  This may break if we get interesting formats.
         */
-       if (map->bus->read_flag_mask)
-               u8[0] |= map->bus->read_flag_mask;
+       u8[0] |= map->read_flag_mask;
 
        trace_regmap_hw_read_start(map->dev, reg,
                                   val_len / map->format.val_bytes);

diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index 9438a89e1573890b9308beb289563d61f0dfd46d..18d4afaac166418a1271bca2778c1690d5309ba1 100644 (file)
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -53,6 +53,12 @@ struct reg_default {
  * @reg_defaults: Power on reset values for registers (for use with
  *                register cache support).
  * @num_reg_defaults: Number of elements in reg_defaults.
+ *
+ * @read_flag_mask: Mask to be set in the top byte of the register when doing
+ *                  a read.
+ * @write_flag_mask: Mask to be set in the top byte of the register when doing
+ *                   a write. If both read_flag_mask and write_flag_mask are
+ *                   empty the regmap_bus default masks are used.
  */
 struct regmap_config {
        int reg_bits;
@@ -66,6 +72,9 @@ struct regmap_config {
        unsigned int max_register;
        struct reg_default *reg_defaults;
        int num_reg_defaults;
+
+       u8 read_flag_mask;
+       u8 write_flag_mask;
 };
 
 typedef int (*regmap_hw_write)(struct device *dev, const void *data,