mfd: bcm590xx: Add support for secondary I2C slave address

BCM590xx utilizes a secondary I2C slave address to access additional
register space. Add support for the secondary address space by
instantiating a dummy I2C device with the appropriate secondary
I2C slave address. Also expose a secondary regmap register space so
that MFD drivers can access this secondary i2c slave address space.

Signed-off-by: Matt Porter <mporter@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

diff --git a/drivers/mfd/bcm590xx.c b/drivers/mfd/bcm590xx.c
index e9a33c7..43cba1a 100644 (file)
--- a/drivers/mfd/bcm590xx.c
+++ b/drivers/mfd/bcm590xx.c
@@ -28,39 +28,71 @@ static const struct mfd_cell bcm590xx_devs[] = {
        },
 };
 
-static const struct regmap_config bcm590xx_regmap_config = {
+static const struct regmap_config bcm590xx_regmap_config_pri = {
        .reg_bits       = 8,
        .val_bits       = 8,
-       .max_register   = BCM590XX_MAX_REGISTER,
+       .max_register   = BCM590XX_MAX_REGISTER_PRI,
        .cache_type     = REGCACHE_RBTREE,
 };
 
-static int bcm590xx_i2c_probe(struct i2c_client *i2c,
+static const struct regmap_config bcm590xx_regmap_config_sec = {
+       .reg_bits       = 8,
+       .val_bits       = 8,
+       .max_register   = BCM590XX_MAX_REGISTER_SEC,
+       .cache_type     = REGCACHE_RBTREE,
+};
+
+static int bcm590xx_i2c_probe(struct i2c_client *i2c_pri,
                              const struct i2c_device_id *id)
 {
        struct bcm590xx *bcm590xx;
        int ret;
 
-       bcm590xx = devm_kzalloc(&i2c->dev, sizeof(*bcm590xx), GFP_KERNEL);
+       bcm590xx = devm_kzalloc(&i2c_pri->dev, sizeof(*bcm590xx), GFP_KERNEL);
        if (!bcm590xx)
                return -ENOMEM;
 
-       i2c_set_clientdata(i2c, bcm590xx);
-       bcm590xx->dev = &i2c->dev;
-       bcm590xx->i2c_client = i2c;
+       i2c_set_clientdata(i2c_pri, bcm590xx);
+       bcm590xx->dev = &i2c_pri->dev;
+       bcm590xx->i2c_pri = i2c_pri;
 
-       bcm590xx->regmap = devm_regmap_init_i2c(i2c, &bcm590xx_regmap_config);
-       if (IS_ERR(bcm590xx->regmap)) {
-               ret = PTR_ERR(bcm590xx->regmap);
-               dev_err(&i2c->dev, "regmap initialization failed: %d\n", ret);
+       bcm590xx->regmap_pri = devm_regmap_init_i2c(i2c_pri,
+                                                &bcm590xx_regmap_config_pri);
+       if (IS_ERR(bcm590xx->regmap_pri)) {
+               ret = PTR_ERR(bcm590xx->regmap_pri);
+               dev_err(&i2c_pri->dev, "primary regmap init failed: %d\n", ret);
                return ret;
        }
 
-       ret = mfd_add_devices(&i2c->dev, -1, bcm590xx_devs,
+       /* Secondary I2C slave address is the base address with A(2) asserted */
+       bcm590xx->i2c_sec = i2c_new_dummy(i2c_pri->adapter,
+                                         i2c_pri->addr | BIT(2));
+       if (IS_ERR_OR_NULL(bcm590xx->i2c_sec)) {
+               dev_err(&i2c_pri->dev, "failed to add secondary I2C device\n");
+               return -ENODEV;
+       }
+       i2c_set_clientdata(bcm590xx->i2c_sec, bcm590xx);
+
+       bcm590xx->regmap_sec = devm_regmap_init_i2c(bcm590xx->i2c_sec,
+                                               &bcm590xx_regmap_config_sec);
+       if (IS_ERR(bcm590xx->regmap_sec)) {
+               ret = PTR_ERR(bcm590xx->regmap_sec);
+               dev_err(&bcm590xx->i2c_sec->dev,
+                       "secondary regmap init failed: %d\n", ret);
+               goto err;
+       }
+
+       ret = mfd_add_devices(&i2c_pri->dev, -1, bcm590xx_devs,
                              ARRAY_SIZE(bcm590xx_devs), NULL, 0, NULL);
-       if (ret < 0)
-               dev_err(&i2c->dev, "failed to add sub-devices: %d\n", ret);
+       if (ret < 0) {
+               dev_err(&i2c_pri->dev, "failed to add sub-devices: %d\n", ret);
+               goto err;
+       }
+
+       return 0;
 
+err:
+       i2c_unregister_device(bcm590xx->i2c_sec);
        return ret;
 }
 

diff --git a/include/linux/mfd/bcm590xx.h b/include/linux/mfd/bcm590xx.h
index 434df2d..267aede 100644 (file)
--- a/include/linux/mfd/bcm590xx.h
+++ b/include/linux/mfd/bcm590xx.h
@@ -19,12 +19,15 @@
 #include <linux/regmap.h>
 
 /* max register address */
-#define BCM590XX_MAX_REGISTER  0xe7
+#define BCM590XX_MAX_REGISTER_PRI      0xe7
+#define BCM590XX_MAX_REGISTER_SEC      0xf0
 
 struct bcm590xx {
        struct device *dev;
-       struct i2c_client *i2c_client;
-       struct regmap *regmap;
+       struct i2c_client *i2c_pri;
+       struct i2c_client *i2c_sec;
+       struct regmap *regmap_pri;
+       struct regmap *regmap_sec;
        unsigned int id;
 };