[PATCH] mfd: twl6040: Handle mclk used for HPPLL and optional internal clock source

[Peter Ujfalusi]

On some boards, like omap5-uevm the MCLK is gated by default and in order
to be able to use the High performance modes of twl6040 it need to be
enabled by SW.
Add support for handling the MCLK source clock via CCF.
At the same time lover the print priority of the notification that the 32K
clock is not proveded so it is not going to be handled by the driver.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@xxxxxx>
---
 Documentation/devicetree/bindings/mfd/twl6040.txt |  4 +--
 drivers/mfd/twl6040.c                             | 34 +++++++++++++++++------
 include/linux/mfd/twl6040.h                       |  3 +-
 3 files changed, 29 insertions(+), 12 deletions(-)

diff --git a/Documentation/devicetree/bindings/mfd/twl6040.txt b/Documentation/devicetree/bindings/mfd/twl6040.txt
index a41157b5d930..e6afdfa3543d 100644
--- a/Documentation/devicetree/bindings/mfd/twl6040.txt
+++ b/Documentation/devicetree/bindings/mfd/twl6040.txt
@@ -19,8 +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"
+- clocks: phandle to the clk32k and/or to mclk clock provider
+- clock-names: Must be "clk32k" for the 32K clock and "mclk" for the MCLK.
 
 Vibra functionality
 Required properties:
diff --git a/drivers/mfd/twl6040.c b/drivers/mfd/twl6040.c
index 852d5874aabb..f3dcf3a85e84 100644
--- a/drivers/mfd/twl6040.c
+++ b/drivers/mfd/twl6040.c
@@ -291,7 +291,7 @@ int twl6040_power(struct twl6040 *twl6040, int on)
 		if (twl6040->power_count++)
 			goto out;
 
-		ret = clk_prepare_enable(twl6040->clk32k);
+		ret = clk_prepare_enable(twl6040->clk32k_clk);
 		if (ret) {
 			twl6040->power_count = 0;
 			goto out;
@@ -304,7 +304,7 @@ int twl6040_power(struct twl6040 *twl6040, int on)
 			/* use automatic power-up sequence */
 			ret = twl6040_power_up_automatic(twl6040);
 			if (ret) {
-				clk_disable_unprepare(twl6040->clk32k);
+				clk_disable_unprepare(twl6040->clk32k_clk);
 				twl6040->power_count = 0;
 				goto out;
 			}
@@ -312,7 +312,7 @@ int twl6040_power(struct twl6040 *twl6040, int on)
 			/* use manual power-up sequence */
 			ret = twl6040_power_up_manual(twl6040);
 			if (ret) {
-				clk_disable_unprepare(twl6040->clk32k);
+				clk_disable_unprepare(twl6040->clk32k_clk);
 				twl6040->power_count = 0;
 				goto out;
 			}
@@ -355,7 +355,10 @@ int twl6040_power(struct twl6040 *twl6040, int on)
 		twl6040->sysclk = 0;
 		twl6040->mclk = 0;
 
-		clk_disable_unprepare(twl6040->clk32k);
+		if (twl6040->pll == TWL6040_SYSCLK_SEL_HPPLL)
+			clk_disable_unprepare(twl6040->mclk_clk);
+
+		clk_disable_unprepare(twl6040->clk32k_clk);
 	}
 
 out:
@@ -427,6 +430,8 @@ int twl6040_set_pll(struct twl6040 *twl6040, int pll_id,
 			ret = -EINVAL;
 			goto pll_out;
 		}
+
+		clk_disable_unprepare(twl6040->mclk_clk);
 		break;
 	case TWL6040_SYSCLK_SEL_HPPLL:
 		/* high-performance PLL can provide only 19.2 MHz */
@@ -468,6 +473,9 @@ int twl6040_set_pll(struct twl6040 *twl6040, int pll_id,
 				goto pll_out;
 			}
 
+			/* When switching to HPPLL, enable the mclk first */
+			if (pll_id != twl6040->pll)
+				clk_prepare_enable(twl6040->mclk_clk);
 			/*
 			 * enable clock slicer to ensure input waveform is
 			 * square
@@ -651,12 +659,20 @@ 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)) {
-		if (PTR_ERR(twl6040->clk32k) == -EPROBE_DEFER)
+	twl6040->clk32k_clk = devm_clk_get(&client->dev, "clk32k");
+	if (IS_ERR(twl6040->clk32k_clk)) {
+		if (PTR_ERR(twl6040->clk32k_clk) == -EPROBE_DEFER)
+			return -EPROBE_DEFER;
+		dev_dbg(&client->dev, "clk32k is not handled\n");
+		twl6040->clk32k_clk = NULL;
+	}
+
+	twl6040->mclk_clk = devm_clk_get(&client->dev, "mclk");
+	if (IS_ERR(twl6040->mclk_clk)) {
+		if (PTR_ERR(twl6040->mclk_clk) == -EPROBE_DEFER)
 			return -EPROBE_DEFER;
-		dev_info(&client->dev, "clk32k is not handled\n");
-		twl6040->clk32k = NULL;
+		dev_dbg(&client->dev, "mclk is not handled\n");
+		twl6040->mclk_clk = NULL;
 	}
 
 	twl6040->supplies[0].supply = "vio";
diff --git a/include/linux/mfd/twl6040.h b/include/linux/mfd/twl6040.h
index 8f9fc3d26e6d..a7c50e54f3e0 100644
--- a/include/linux/mfd/twl6040.h
+++ b/include/linux/mfd/twl6040.h
@@ -224,7 +224,8 @@ 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 clk *clk32k_clk;
+	struct clk *mclk_clk;
 	struct mutex mutex;
 	struct mutex irq_mutex;
 	struct mfd_cell cells[TWL6040_CELLS];
-- 
2.8.2