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authorJonathan Corbet <corbet@lwn.net>2007-05-22 00:37:58 -0300
committerMauro Carvalho Chehab <mchehab@infradead.org>2007-05-22 16:16:27 -0300
commit7acf90c70c6ee063f7465b2f10e2083bc49f355b (patch)
tree6b00a98e964864b400ec03dc52598cb5aa0c1ea7 /drivers/media/video/cafe_ccic.c
parent82c01d3d5a26f82aea1fb2e9a357dfb6404f44db (diff)
V4L/DVB (5690): Cafe_ccic: Properly power down the sensor
The proper method for powering down the sensor on OLPC systems has changed somewhat; in particular, the sensor must be powered down completely (rather than simply told to power down) or the associated "camera active" LED will stay on. Signed-off-by: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Diffstat (limited to 'drivers/media/video/cafe_ccic.c')
-rw-r--r--drivers/media/video/cafe_ccic.c18
1 files changed, 17 insertions, 1 deletions
diff --git a/drivers/media/video/cafe_ccic.c b/drivers/media/video/cafe_ccic.c
index 96254dbaf625..c08f650df423 100644
--- a/drivers/media/video/cafe_ccic.c
+++ b/drivers/media/video/cafe_ccic.c
@@ -775,6 +775,12 @@ static void cafe_ctlr_power_up(struct cafe_camera *cam)
spin_lock_irqsave(&cam->dev_lock, flags);
cafe_reg_clear_bit(cam, REG_CTRL1, C1_PWRDWN);
/*
+ * Part one of the sensor dance: turn the global
+ * GPIO signal on.
+ */
+ cafe_reg_write(cam, REG_GL_FCR, GFCR_GPIO_ON);
+ cafe_reg_write(cam, REG_GL_GPIOR, GGPIO_OUT|GGPIO_VAL);
+ /*
* Put the sensor into operational mode (assumes OLPC-style
* wiring). Control 0 is reset - set to 1 to operate.
* Control 1 is power down, set to 0 to operate.
@@ -784,6 +790,7 @@ static void cafe_ctlr_power_up(struct cafe_camera *cam)
cafe_reg_write(cam, REG_GPR, GPR_C1EN|GPR_C0EN|GPR_C0);
// mdelay(1); /* Enough? */
spin_unlock_irqrestore(&cam->dev_lock, flags);
+ msleep(5); /* Just to be sure */
}
static void cafe_ctlr_power_down(struct cafe_camera *cam)
@@ -792,6 +799,8 @@ static void cafe_ctlr_power_down(struct cafe_camera *cam)
spin_lock_irqsave(&cam->dev_lock, flags);
cafe_reg_write(cam, REG_GPR, GPR_C1EN|GPR_C0EN|GPR_C1);
+ cafe_reg_write(cam, REG_GL_FCR, GFCR_GPIO_ON);
+ cafe_reg_write(cam, REG_GL_GPIOR, GGPIO_OUT);
cafe_reg_set_bit(cam, REG_CTRL1, C1_PWRDWN);
spin_unlock_irqrestore(&cam->dev_lock, flags);
}
@@ -851,6 +860,7 @@ static int cafe_cam_init(struct cafe_camera *cam)
ret = 0;
cam->state = S_IDLE;
out:
+ cafe_ctlr_power_down(cam);
mutex_unlock(&cam->s_mutex);
return ret;
}
@@ -2103,10 +2113,16 @@ static int cafe_pci_probe(struct pci_dev *pdev,
ret = request_irq(pdev->irq, cafe_irq, IRQF_SHARED, "cafe-ccic", cam);
if (ret)
goto out_iounmap;
+ /*
+ * Initialize the controller and leave it powered up. It will
+ * stay that way until the sensor driver shows up.
+ */
cafe_ctlr_init(cam);
cafe_ctlr_power_up(cam);
/*
- * Set up I2C/SMBUS communications
+ * Set up I2C/SMBUS communications. We have to drop the mutex here
+ * because the sensor could attach in this call chain, leading to
+ * unsightly deadlocks.
*/
mutex_unlock(&cam->s_mutex); /* attach can deadlock */
ret = cafe_smbus_setup(cam);

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