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From deb568b94c448aa7ffcc9e6788bcf9069fd3b864 Mon Sep 17 00:00:00 2001
From: Steve Sakoman <sakoman@gmail.com>
Date: Tue, 15 Dec 2009 15:24:10 -0800
Subject: [PATCH 04/16] drivers: input: touchscreen: ads7846: return ENODEV if device is not found
Signed-off-by: Steve Sakoman <sakoman@gmail.com>
---
drivers/input/touchscreen/ads7846.c | 13 ++++++++++---
1 files changed, 10 insertions(+), 3 deletions(-)
diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c
index 09c8109..7cc9973 100644
--- a/drivers/input/touchscreen/ads7846.c
+++ b/drivers/input/touchscreen/ads7846.c
@@ -1170,9 +1170,16 @@ static int __devinit ads7846_probe(struct spi_device *spi)
/* take a first sample, leaving nPENIRQ active and vREF off; avoid
* the touchscreen, in case it's not connected.
*/
- (void) ads7846_read12_ser(&spi->dev,
+ err = ads7846_read12_ser(&spi->dev,
READ_12BIT_SER(vaux) | ADS_PD10_ALL_ON);
+ /* if sample is all 0's or all 1's then there is no device on spi */
+ if ( (err == 0x000) || (err == 0xfff)) {
+ dev_info(&spi->dev, "no device detected, test read result was 0x%08X\n", err);
+ err = -ENODEV;
+ goto err_free_irq;
+ }
+
err = sysfs_create_group(&spi->dev.kobj, &ads784x_attr_group);
if (err)
goto err_remove_hwmon;
@@ -1190,7 +1197,7 @@ static int __devinit ads7846_probe(struct spi_device *spi)
err_free_irq:
free_irq(spi->irq, ts);
err_free_gpio:
- if (ts->gpio_pendown != -1)
+ if (!ts->get_pendown_state && ts->gpio_pendown != -1)
gpio_free(ts->gpio_pendown);
err_cleanup_filter:
if (ts->filter_cleanup)
@@ -1217,7 +1224,7 @@ static int __devexit ads7846_remove(struct spi_device *spi)
/* suspend left the IRQ disabled */
enable_irq(ts->spi->irq);
- if (ts->gpio_pendown != -1)
+ if (!ts->get_pendown_state && ts->gpio_pendown != -1)
gpio_free(ts->gpio_pendown);
if (ts->filter_cleanup)
--
1.6.2.4
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