From 7e5f28ca06be8efdbe2c03a252e09a2d5a1b8384 Mon Sep 17 00:00:00 2001 From: Steve Sakoman Date: Tue, 15 Dec 2009 15:24:10 -0800 Subject: [PATCH 18/30] drivers: input: touchscreen: ads7846: return ENODEV if device is not found Signed-off-by: Steve Sakoman --- 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 52d2ca1..ce12c63 100644 --- a/drivers/input/touchscreen/ads7846.c +++ b/drivers/input/touchscreen/ads7846.c @@ -1161,9 +1161,16 @@ 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; @@ -1181,7 +1188,7 @@ 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) @@ -1208,7 +1215,7 @@ 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) -- 1.6.6.1