mfd: twl6040: Optional clk32k clock handling

In certain boards the source for the clk32k clock can be gated. In these
boards the clk32k clock can be provided to the driver and it is going to be
enabled/disabled when it is needed.
If the clk32k clock is not provided the driver will assume that it is always
running.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

diff --git a/Documentation/devicetree/bindings/mfd/twl6040.txt b/Documentation/devicetree/bindings/mfd/twl6040.txt
index 0f5dd709d752490815fab1a978b8c2ff1c1f383b..a41157b5d930d2c0ed1dfaee5fd9c0aa9d392d1e 100644 (file)
--- a/Documentation/devicetree/bindings/mfd/twl6040.txt
+++ b/Documentation/devicetree/bindings/mfd/twl6040.txt
@@ -19,6 +19,8 @@ Required properties:
 
 Optional properties, nodes:
 - enable-active-high: To power on the twl6040 during boot.
+- clocks: phandle to the clk32k clock provider
+- clock-names: Must be "clk32k"
 
 Vibra functionality
 Required properties:

diff --git a/drivers/mfd/twl6040.c b/drivers/mfd/twl6040.c
index cb37bb8f8e41e76877a098f18941c06ee4d08864..574774d7f826ab3d6ca047e22fcf7c6f239177ec 100644 (file)
--- a/drivers/mfd/twl6040.c
+++ b/drivers/mfd/twl6040.c
@@ -291,6 +291,8 @@ int twl6040_power(struct twl6040 *twl6040, int on)
                if (twl6040->power_count++)
                        goto out;
 
+               clk_prepare_enable(twl6040->clk32k);
+
                /* Allow writes to the chip */
                regcache_cache_only(twl6040->regmap, false);
 
@@ -346,6 +348,8 @@ int twl6040_power(struct twl6040 *twl6040, int on)
 
                twl6040->sysclk = 0;
                twl6040->mclk = 0;
+
+               clk_disable_unprepare(twl6040->clk32k);
        }
 
 out:
@@ -644,6 +648,12 @@ static int twl6040_probe(struct i2c_client *client,
 
        i2c_set_clientdata(client, twl6040);
 
+       twl6040->clk32k = devm_clk_get(&client->dev, "clk32k");
+       if (IS_ERR(twl6040->clk32k)) {
+               dev_info(&client->dev, "clk32k is not handled\n");
+               twl6040->clk32k = NULL;
+       }
+
        twl6040->supplies[0].supply = "vio";
        twl6040->supplies[1].supply = "v2v1";
        ret = devm_regulator_bulk_get(&client->dev, TWL6040_NUM_SUPPLIES,

diff --git a/include/linux/mfd/twl6040.h b/include/linux/mfd/twl6040.h
index a69d16b30c1862e610a05a4d76fe97e38c1dcf91..8f9fc3d26e6d1e8582938dc20004c1988aad4147 100644 (file)
--- a/include/linux/mfd/twl6040.h
+++ b/include/linux/mfd/twl6040.h
@@ -28,6 +28,7 @@
 #include <linux/interrupt.h>
 #include <linux/mfd/core.h>
 #include <linux/regulator/consumer.h>
+#include <linux/clk.h>
 
 #define TWL6040_REG_ASICID             0x01
 #define TWL6040_REG_ASICREV            0x02
@@ -223,6 +224,7 @@ struct twl6040 {
        struct regmap *regmap;
        struct regmap_irq_chip_data *irq_data;
        struct regulator_bulk_data supplies[2]; /* supplies for vio, v2v1 */
+       struct clk *clk32k;
        struct mutex mutex;
        struct mutex irq_mutex;
        struct mfd_cell cells[TWL6040_CELLS];