[PATCH v2] Input: Make ADS7846 independent on regulator

[Marek Vasut]

In case regulator was not found, ADS7846 failed to probe.

This fixes a problem on some Sharp Zaurus devices, where there is no regulator
present and the touchscreen is used.

Signed-off-by: Marek Vasut <marek.vasut at gmail.com>
---
 drivers/input/touchscreen/ads7846.c |   38 +++++++++++++++++++---------------
 1 files changed, 21 insertions(+), 17 deletions(-)

diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index a9fdf55..53b318b 100644
--- a/drivers/input/touchscreen/ads7846.c
+++ b/drivers/input/touchscreen/ads7846.c
@@ -791,7 +791,8 @@ static void ads7846_disable(struct ads7846 *ts)
 		}
 	}
 
-	regulator_disable(ts->reg);
+	if (ts->reg)
+		regulator_disable(ts->reg);
 
 	/* we know the chip's in lowpower mode since we always
 	 * leave it that way after every request
@@ -804,7 +805,8 @@ static void ads7846_enable(struct ads7846 *ts)
 	if (!ts->disabled)
 		return;
 
-	regulator_enable(ts->reg);
+	if (ts->reg)
+		regulator_enable(ts->reg);
 
 	ts->disabled = 0;
 	ts->irq_disabled = 0;
@@ -1162,16 +1164,15 @@ static int __devinit ads7846_probe(struct spi_device *spi)
 	ts->last_msg = m;
 
 	ts->reg = regulator_get(&spi->dev, "vcc");
-	if (IS_ERR(ts->reg)) {
-		err = PTR_ERR(ts->reg);
-		dev_err(&spi->dev, "unable to get regulator: %d\n", err);
-		goto err_free_gpio;
-	}
-
-	err = regulator_enable(ts->reg);
-	if (err) {
-		dev_err(&spi->dev, "unable to enable regulator: %d\n", err);
-		goto err_put_regulator;
+	if (IS_ERR(ts->reg))
+		ts->reg = NULL;
+	else {
+		err = regulator_enable(ts->reg);
+		if (err) {
+			dev_err(&spi->dev, "unable to enable regulator: %d\n",
+				err);
+			goto err_put_regulator;
+		}
 	}
 
 	if (request_irq(spi->irq, ads7846_irq, IRQF_TRIGGER_FALLING,
@@ -1218,10 +1219,11 @@ static int __devinit ads7846_probe(struct spi_device *spi)
  err_free_irq:
 	free_irq(spi->irq, ts);
  err_disable_regulator:
-	regulator_disable(ts->reg);
+	if (ts->reg)
+		regulator_disable(ts->reg);
  err_put_regulator:
-	regulator_put(ts->reg);
- err_free_gpio:
+	if (ts->reg)
+		regulator_put(ts->reg);
 	if (ts->gpio_pendown != -1)
 		gpio_free(ts->gpio_pendown);
  err_cleanup_filter:
@@ -1251,8 +1253,10 @@ static int __devexit ads7846_remove(struct spi_device *spi)
 	/* suspend left the IRQ disabled */
 	enable_irq(ts->spi->irq);
 
-	regulator_disable(ts->reg);
-	regulator_put(ts->reg);
+	if (ts->reg) {
+		regulator_disable(ts->reg);
+		regulator_put(ts->reg);
+	}
 
 	if (ts->gpio_pendown != -1)
 		gpio_free(ts->gpio_pendown);
-- 
1.7.1