[PATCH v4 1/4] mfd: arizona: Factor out SYSCLK enable from wm5102 hardware patch

[Charles Keepax <ckeepax@opensource.wolfsonmicro.com>]

wm5102 applies a custom hardware boot sequence, for this the SYSCLK
needs to be enabled. This patch factors out the code that enables
SYSCLK for this sequence such that it can be used for other boot time
operations that require SYSCLK.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
---

Changes since v3:
 - Simplify error handling in arizona_disable_freerun_sysclk
 - Update some small formatting issues

Thanks,
Charles

 drivers/mfd/arizona-core.c |  102 +++++++++++++++++++++++++++++---------------
 1 files changed, 68 insertions(+), 34 deletions(-)

diff --git a/drivers/mfd/arizona-core.c b/drivers/mfd/arizona-core.c
index 6ca6dfa..13428cf 100644
--- a/drivers/mfd/arizona-core.c
+++ b/drivers/mfd/arizona-core.c
@@ -250,20 +250,26 @@ static int arizona_wait_for_boot(struct arizona *arizona)
 	return ret;
 }
 
-static int arizona_apply_hardware_patch(struct arizona* arizona)
+struct arizona_sysclk_state {
+	unsigned int fll;
+	unsigned int sysclk;
+};
+
+static int arizona_enable_freerun_sysclk(struct arizona *arizona,
+					 struct arizona_sysclk_state *state)
 {
-	unsigned int fll, sysclk;
 	int ret, err;
 
 	/* Cache existing FLL and SYSCLK settings */
-	ret = regmap_read(arizona->regmap, ARIZONA_FLL1_CONTROL_1, &fll);
-	if (ret != 0) {
+	ret = regmap_read(arizona->regmap, ARIZONA_FLL1_CONTROL_1, &state->fll);
+	if (ret) {
 		dev_err(arizona->dev, "Failed to cache FLL settings: %d\n",
 			ret);
 		return ret;
 	}
-	ret = regmap_read(arizona->regmap, ARIZONA_SYSTEM_CLOCK_1, &sysclk);
-	if (ret != 0) {
+	ret = regmap_read(arizona->regmap, ARIZONA_SYSTEM_CLOCK_1,
+			  &state->sysclk);
+	if (ret) {
 		dev_err(arizona->dev, "Failed to cache SYSCLK settings: %d\n",
 			ret);
 		return ret;
@@ -272,7 +278,7 @@ static int arizona_apply_hardware_patch(struct arizona* arizona)
 	/* Start up SYSCLK using the FLL in free running mode */
 	ret = regmap_write(arizona->regmap, ARIZONA_FLL1_CONTROL_1,
 			ARIZONA_FLL1_ENA | ARIZONA_FLL1_FREERUN);
-	if (ret != 0) {
+	if (ret) {
 		dev_err(arizona->dev,
 			"Failed to start FLL in freerunning mode: %d\n",
 			ret);
@@ -281,53 +287,81 @@ static int arizona_apply_hardware_patch(struct arizona* arizona)
 	ret = arizona_poll_reg(arizona, 25, ARIZONA_INTERRUPT_RAW_STATUS_5,
 			       ARIZONA_FLL1_CLOCK_OK_STS,
 			       ARIZONA_FLL1_CLOCK_OK_STS);
-	if (ret != 0) {
+	if (ret) {
 		ret = -ETIMEDOUT;
 		goto err_fll;
 	}
 
 	ret = regmap_write(arizona->regmap, ARIZONA_SYSTEM_CLOCK_1, 0x0144);
-	if (ret != 0) {
+	if (ret) {
 		dev_err(arizona->dev, "Failed to start SYSCLK: %d\n", ret);
 		goto err_fll;
 	}
 
+	return 0;
+
+err_fll:
+	err = regmap_write(arizona->regmap, ARIZONA_FLL1_CONTROL_1, state->fll);
+	if (err)
+		dev_err(arizona->dev,
+			"Failed to re-apply old FLL settings: %d\n", err);
+
+	return ret;
+}
+
+static int arizona_disable_freerun_sysclk(struct arizona *arizona,
+					  struct arizona_sysclk_state *state)
+{
+	int ret;
+
+	ret = regmap_write(arizona->regmap, ARIZONA_SYSTEM_CLOCK_1,
+			   state->sysclk);
+	if (ret) {
+		dev_err(arizona->dev,
+			"Failed to re-apply old SYSCLK settings: %d\n", ret);
+		return ret;
+	}
+
+	ret = regmap_write(arizona->regmap, ARIZONA_FLL1_CONTROL_1, state->fll);
+	if (ret) {
+		dev_err(arizona->dev,
+			"Failed to re-apply old FLL settings: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int wm5102_apply_hardware_patch(struct arizona *arizona)
+{
+	struct arizona_sysclk_state state;
+	int err, ret;
+
+	ret = arizona_enable_freerun_sysclk(arizona, &state);
+	if (ret)
+		return ret;
+
 	/* Start the write sequencer and wait for it to finish */
 	ret = regmap_write(arizona->regmap, ARIZONA_WRITE_SEQUENCER_CTRL_0,
 			ARIZONA_WSEQ_ENA | ARIZONA_WSEQ_START | 160);
-	if (ret != 0) {
+	if (ret) {
 		dev_err(arizona->dev, "Failed to start write sequencer: %d\n",
 			ret);
-		goto err_sysclk;
+		goto err;
 	}
+
 	ret = arizona_poll_reg(arizona, 5, ARIZONA_WRITE_SEQUENCER_CTRL_1,
 			       ARIZONA_WSEQ_BUSY, 0);
-	if (ret != 0) {
+	if (ret) {
 		regmap_write(arizona->regmap, ARIZONA_WRITE_SEQUENCER_CTRL_0,
-				ARIZONA_WSEQ_ABORT);
+			     ARIZONA_WSEQ_ABORT);
 		ret = -ETIMEDOUT;
 	}
 
-err_sysclk:
-	err = regmap_write(arizona->regmap, ARIZONA_SYSTEM_CLOCK_1, sysclk);
-	if (err != 0) {
-		dev_err(arizona->dev,
-			"Failed to re-apply old SYSCLK settings: %d\n",
-			err);
-	}
-
-err_fll:
-	err = regmap_write(arizona->regmap, ARIZONA_FLL1_CONTROL_1, fll);
-	if (err != 0) {
-		dev_err(arizona->dev,
-			"Failed to re-apply old FLL settings: %d\n",
-			err);
-	}
+err:
+	err = arizona_disable_freerun_sysclk(arizona, &state);
 
-	if (ret != 0)
-		return ret;
-	else
-		return err;
+	return ret ?: err;
 }
 
 #ifdef CONFIG_PM
@@ -366,7 +400,7 @@ static int arizona_runtime_resume(struct device *dev)
 			goto err;
 		}
 
-		ret = arizona_apply_hardware_patch(arizona);
+		ret = wm5102_apply_hardware_patch(arizona);
 		if (ret != 0) {
 			dev_err(arizona->dev,
 				"Failed to apply hardware patch: %d\n",
@@ -891,7 +925,7 @@ int arizona_dev_init(struct arizona *arizona)
 
 		switch (arizona->type) {
 		case WM5102:
-			ret = arizona_apply_hardware_patch(arizona);
+			ret = wm5102_apply_hardware_patch(arizona);
 			if (ret != 0) {
 				dev_err(arizona->dev,
 					"Failed to apply hardware patch: %d\n",
-- 
1.7.2.5