[PATCH v3 0/5] MT9M032 and MT9P031 sensor patches

[PATCH v3 0/5] MT9M032 and MT9P031 sensor patches

[Laurent Pinchart]

Hi,

I've missed a 64-bit division issue in v2. Here's a v3 that fixes that. Sorry
for the noise.

Danny Kukawka (1):
  mt9p031: Remove duplicate media/v4l2-subdev.h include

Laurent Pinchart (3):
  mt9p031: Remove unused xskip and yskip fields in struct mt9p031
  v4l: Aptina-style sensor PLL support
  mt9p031: Use generic PLL setup code

Martin Hostettler (1):
  v4l: Add driver for Micron MT9M032 camera sensor

 drivers/media/video/Kconfig      |   12 +
 drivers/media/video/Makefile     |    5 +
 drivers/media/video/aptina-pll.c |  174 ++++++++
 drivers/media/video/aptina-pll.h |   56 +++
 drivers/media/video/mt9m032.c    |  825 ++++++++++++++++++++++++++++++++++++++
 drivers/media/video/mt9p031.c    |   67 ++--
 include/media/mt9m032.h          |   36 ++
 7 files changed, 1135 insertions(+), 40 deletions(-)
 create mode 100644 drivers/media/video/aptina-pll.c
 create mode 100644 drivers/media/video/aptina-pll.h
 create mode 100644 drivers/media/video/mt9m032.c
 create mode 100644 include/media/mt9m032.h

-- 
Regards,

Laurent Pinchart

[PATCH v3 1/5] mt9p031: Remove duplicate media/v4l2-subdev.h include

[Laurent Pinchart]

From: Danny Kukawka <danny.kukawka@bisect.de>

drivers/media/video/mt9p031.c included 'media/v4l2-subdev.h' twice,
remove the duplicate.

Signed-off-by: Danny Kukawka <danny.kukawka@bisect.de>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 drivers/media/video/mt9p031.c |    1 -
 1 files changed, 0 insertions(+), 1 deletions(-)

diff --git a/drivers/media/video/mt9p031.c b/drivers/media/video/mt9p031.c
index 93c3ec7..dd937df 100644
--- a/drivers/media/video/mt9p031.c
+++ b/drivers/media/video/mt9p031.c
@@ -19,7 +19,6 @@
 #include <linux/log2.h>
 #include <linux/pm.h>
 #include <linux/slab.h>
-#include <media/v4l2-subdev.h>
 #include <linux/videodev2.h>
 
 #include <media/mt9p031.h>
-- 
1.7.3.4

[PATCH v3 2/5] mt9p031: Remove unused xskip and yskip fields in struct mt9p031

[Laurent Pinchart]

The fields are set but never used, remove them.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 drivers/media/video/mt9p031.c |    4 ----
 1 files changed, 0 insertions(+), 4 deletions(-)

diff --git a/drivers/media/video/mt9p031.c b/drivers/media/video/mt9p031.c
index dd937df..52dd9f8 100644
--- a/drivers/media/video/mt9p031.c
+++ b/drivers/media/video/mt9p031.c
@@ -114,8 +114,6 @@ struct mt9p031 {
 	struct mt9p031_platform_data *pdata;
 	struct mutex power_lock; /* lock to protect power_count */
 	int power_count;
-	u16 xskip;
-	u16 yskip;
 
 	const struct mt9p031_pll_divs *pll;
 
@@ -784,8 +782,6 @@ static int mt9p031_open(struct v4l2_subdev *subdev, struct v4l2_subdev_fh *fh)
 	format->field = V4L2_FIELD_NONE;
 	format->colorspace = V4L2_COLORSPACE_SRGB;
 
-	mt9p031->xskip = 1;
-	mt9p031->yskip = 1;
 	return mt9p031_set_power(subdev, 1);
 }
 
-- 
1.7.3.4

[PATCH v3 3/5] v4l: Aptina-style sensor PLL support

[Laurent Pinchart]

Add a generic helper function to compute PLL parameters for PLL found in
several Aptina sensors.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Sakari Ailus <sakari.ailus@iki.fi>
---
 drivers/media/video/Kconfig      |    3 +
 drivers/media/video/Makefile     |    4 +
 drivers/media/video/aptina-pll.c |  174 ++++++++++++++++++++++++++++++++++++++
 drivers/media/video/aptina-pll.h |   56 ++++++++++++
 4 files changed, 237 insertions(+), 0 deletions(-)
 create mode 100644 drivers/media/video/aptina-pll.c
 create mode 100644 drivers/media/video/aptina-pll.h

diff --git a/drivers/media/video/Kconfig b/drivers/media/video/Kconfig
index 9495b6a..7867b0b 100644
--- a/drivers/media/video/Kconfig
+++ b/drivers/media/video/Kconfig
@@ -459,6 +459,9 @@ config VIDEO_AK881X
 
 comment "Camera sensor devices"
 
+config VIDEO_APTINA_PLL
+	tristate
+
 config VIDEO_OV7670
 	tristate "OmniVision OV7670 sensor support"
 	depends on I2C && VIDEO_V4L2
diff --git a/drivers/media/video/Makefile b/drivers/media/video/Makefile
index 563443c..d1304e1 100644
--- a/drivers/media/video/Makefile
+++ b/drivers/media/video/Makefile
@@ -22,6 +22,10 @@ endif
 
 obj-$(CONFIG_VIDEO_V4L2_COMMON) += v4l2-common.o
 
+# Helper modules
+
+obj-$(CONFIG_VIDEO_APTINA_PLL) += aptina-pll.o
+
 # All i2c modules must come first:
 
 obj-$(CONFIG_VIDEO_TUNER) += tuner.o
diff --git a/drivers/media/video/aptina-pll.c b/drivers/media/video/aptina-pll.c
new file mode 100644
index 0000000..0bd3813
--- /dev/null
+++ b/drivers/media/video/aptina-pll.c
@@ -0,0 +1,174 @@
+/*
+ * Aptina Sensor PLL Configuration
+ *
+ * Copyright (C) 2012 Laurent Pinchart <laurent.pinchart@ideasonboard.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+#include <linux/device.h>
+#include <linux/gcd.h>
+#include <linux/kernel.h>
+#include <linux/lcm.h>
+#include <linux/module.h>
+
+#include "aptina-pll.h"
+
+int aptina_pll_calculate(struct device *dev,
+			 const struct aptina_pll_limits *limits,
+			 struct aptina_pll *pll)
+{
+	unsigned int mf_min;
+	unsigned int mf_max;
+	unsigned int p1_min;
+	unsigned int p1_max;
+	unsigned int p1;
+	unsigned int div;
+
+	dev_dbg(dev, "PLL: ext clock %u pix clock %u\n",
+		pll->ext_clock, pll->pix_clock);
+
+	if (pll->ext_clock < limits->ext_clock_min ||
+	    pll->ext_clock > limits->ext_clock_max) {
+		dev_err(dev, "pll: invalid external clock frequency.\n");
+		return -EINVAL;
+	}
+
+	if (pll->pix_clock == 0 || pll->pix_clock > limits->pix_clock_max) {
+		dev_err(dev, "pll: invalid pixel clock frequency.\n");
+		return -EINVAL;
+	}
+
+	/* Compute the multiplier M and combined N*P1 divisor. */
+	div = gcd(pll->pix_clock, pll->ext_clock);
+	pll->m = pll->pix_clock / div;
+	div = pll->ext_clock / div;
+
+	/* We now have the smallest M and N*P1 values that will result in the
+	 * desired pixel clock frequency, but they might be out of the valid
+	 * range. Compute the factor by which we should multiply them given the
+	 * following constraints:
+	 *
+	 * - minimum/maximum multiplier
+	 * - minimum/maximum multiplier output clock frequency assuming the
+	 *   minimum/maximum N value
+	 * - minimum/maximum combined N*P1 divisor
+	 */
+	mf_min = DIV_ROUND_UP(limits->m_min, pll->m);
+	mf_min = max(mf_min, limits->out_clock_min /
+		     (pll->ext_clock / limits->n_min * pll->m));
+	mf_min = max(mf_min, limits->n_min * limits->p1_min / div);
+	mf_max = limits->m_max / pll->m;
+	mf_max = min(mf_max, limits->out_clock_max /
+		    (pll->ext_clock / limits->n_max * pll->m));
+	mf_max = min(mf_max, DIV_ROUND_UP(limits->n_max * limits->p1_max, div));
+
+	dev_dbg(dev, "pll: mf min %u max %u\n", mf_min, mf_max);
+	if (mf_min > mf_max) {
+		dev_err(dev, "pll: no valid combined N*P1 divisor.\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * We're looking for the highest acceptable P1 value for which a
+	 * multiplier factor MF exists that fulfills the following conditions:
+	 *
+	 * 1. p1 is in the [p1_min, p1_max] range given by the limits and is
+	 *    even
+	 * 2. mf is in the [mf_min, mf_max] range computed above
+	 * 3. div * mf is a multiple of p1, in order to compute
+	 *	n = div * mf / p1
+	 *	m = pll->m * mf
+	 * 4. the internal clock frequency, given by ext_clock / n, is in the
+	 *    [int_clock_min, int_clock_max] range given by the limits
+	 * 5. the output clock frequency, given by ext_clock / n * m, is in the
+	 *    [out_clock_min, out_clock_max] range given by the limits
+	 *
+	 * The first naive approach is to iterate over all p1 values acceptable
+	 * according to (1) and all mf values acceptable according to (2), and
+	 * stop at the first combination that fulfills (3), (4) and (5). This
+	 * has a O(n^2) complexity.
+	 *
+	 * Instead of iterating over all mf values in the [mf_min, mf_max] range
+	 * we can compute the mf increment between two acceptable values
+	 * according to (3) with
+	 *
+	 *	mf_inc = p1 / gcd(div, p1)			(6)
+	 *
+	 * and round the minimum up to the nearest multiple of mf_inc. This will
+	 * restrict the number of mf values to be checked.
+	 *
+	 * Furthermore, conditions (4) and (5) only restrict the range of
+	 * acceptable p1 and mf values by modifying the minimum and maximum
+	 * limits. (5) can be expressed as
+	 *
+	 *	ext_clock / (div * mf / p1) * m * mf >= out_clock_min
+	 *	ext_clock / (div * mf / p1) * m * mf <= out_clock_max
+	 *
+	 * or
+	 *
+	 *	p1 >= out_clock_min * div / (ext_clock * m)	(7)
+	 *	p1 <= out_clock_max * div / (ext_clock * m)
+	 *
+	 * Similarly, (4) can be expressed as
+	 *
+	 *	mf >= ext_clock * p1 / (int_clock_max * div)	(8)
+	 *	mf <= ext_clock * p1 / (int_clock_min * div)
+	 *
+	 * We can thus iterate over the restricted p1 range defined by the
+	 * combination of (1) and (7), and then compute the restricted mf range
+	 * defined by the combination of (2), (6) and (8). If the resulting mf
+	 * range is not empty, any value in the mf range is acceptable. We thus
+	 * select the mf lwoer bound and the corresponding p1 value.
+	 */
+	if (limits->p1_min == 0) {
+		dev_err(dev, "pll: P1 minimum value must be >0.\n");
+		return -EINVAL;
+	}
+
+	p1_min = max(limits->p1_min, DIV_ROUND_UP(limits->out_clock_min * div,
+		     pll->ext_clock * pll->m));
+	p1_max = min(limits->p1_max, limits->out_clock_max * div /
+		     (pll->ext_clock * pll->m));
+
+	for (p1 = p1_max & ~1; p1 >= p1_min; p1 -= 2) {
+		unsigned int mf_inc = p1 / gcd(div, p1);
+		unsigned int mf_high;
+		unsigned int mf_low;
+
+		mf_low = max(roundup(mf_min, mf_inc),
+			     DIV_ROUND_UP(pll->ext_clock * p1,
+			       limits->int_clock_max * div));
+		mf_high = min(mf_max, pll->ext_clock * p1 /
+			      (limits->int_clock_min * div));
+
+		if (mf_low > mf_high)
+			continue;
+
+		pll->n = div * mf_low / p1;
+		pll->m *= mf_low;
+		pll->p1 = p1;
+		dev_dbg(dev, "PLL: N %u M %u P1 %u\n", pll->n, pll->m, pll->p1);
+		return 0;
+	}
+
+	dev_err(dev, "pll: no valid N and P1 divisors found.\n");
+	return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(aptina_pll_calculate);
+
+MODULE_DESCRIPTION("Aptina PLL Helpers");
+MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/media/video/aptina-pll.h b/drivers/media/video/aptina-pll.h
new file mode 100644
index 0000000..b370e34
--- /dev/null
+++ b/drivers/media/video/aptina-pll.h
@@ -0,0 +1,56 @@
+/*
+ * Aptina Sensor PLL Configuration
+ *
+ * Copyright (C) 2012 Laurent Pinchart <laurent.pinchart@ideasonboard.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+#ifndef __APTINA_PLL_H
+#define __APTINA_PLL_H
+
+struct aptina_pll {
+	unsigned int ext_clock;
+	unsigned int pix_clock;
+
+	unsigned int n;
+	unsigned int m;
+	unsigned int p1;
+};
+
+struct aptina_pll_limits {
+	unsigned int ext_clock_min;
+	unsigned int ext_clock_max;
+	unsigned int int_clock_min;
+	unsigned int int_clock_max;
+	unsigned int out_clock_min;
+	unsigned int out_clock_max;
+	unsigned int pix_clock_max;
+
+	unsigned int n_min;
+	unsigned int n_max;
+	unsigned int m_min;
+	unsigned int m_max;
+	unsigned int p1_min;
+	unsigned int p1_max;
+};
+
+struct device;
+
+int aptina_pll_calculate(struct device *dev,
+			 const struct aptina_pll_limits *limits,
+			 struct aptina_pll *pll);
+
+#endif /* __APTINA_PLL_H */
-- 
1.7.3.4

[PATCH v3 4/5] mt9p031: Use generic PLL setup code

[Laurent Pinchart]

Compute the PLL parameters at runtime using the generic Aptina PLL
helper.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 drivers/media/video/Kconfig   |    1 +
 drivers/media/video/mt9p031.c |   62 ++++++++++++++++++-----------------------
 2 files changed, 28 insertions(+), 35 deletions(-)

diff --git a/drivers/media/video/Kconfig b/drivers/media/video/Kconfig
index 7867b0b..666836d 100644
--- a/drivers/media/video/Kconfig
+++ b/drivers/media/video/Kconfig
@@ -473,6 +473,7 @@ config VIDEO_OV7670
 config VIDEO_MT9P031
 	tristate "Aptina MT9P031 support"
 	depends on I2C && VIDEO_V4L2 && VIDEO_V4L2_SUBDEV_API
+	select VIDEO_APTINA_PLL
 	---help---
 	  This is a Video4Linux2 sensor-level driver for the Aptina
 	  (Micron) mt9p031 5 Mpixel camera.
diff --git a/drivers/media/video/mt9p031.c b/drivers/media/video/mt9p031.c
index 52dd9f8..3bcd14b 100644
--- a/drivers/media/video/mt9p031.c
+++ b/drivers/media/video/mt9p031.c
@@ -27,6 +27,8 @@
 #include <media/v4l2-device.h>
 #include <media/v4l2-subdev.h>
 
+#include "aptina-pll.h"
+
 #define MT9P031_PIXEL_ARRAY_WIDTH			2752
 #define MT9P031_PIXEL_ARRAY_HEIGHT			2004
 
@@ -97,14 +99,6 @@
 #define MT9P031_TEST_PATTERN_RED			0xa2
 #define MT9P031_TEST_PATTERN_BLUE			0xa3
 
-struct mt9p031_pll_divs {
-	u32 ext_freq;
-	u32 target_freq;
-	u8 m;
-	u8 n;
-	u8 p1;
-};
-
 struct mt9p031 {
 	struct v4l2_subdev subdev;
 	struct media_pad pad;
@@ -115,7 +109,7 @@ struct mt9p031 {
 	struct mutex power_lock; /* lock to protect power_count */
 	int power_count;
 
-	const struct mt9p031_pll_divs *pll;
+	struct aptina_pll pll;
 
 	/* Registers cache */
 	u16 output_control;
@@ -183,33 +177,31 @@ static int mt9p031_reset(struct mt9p031 *mt9p031)
 					  0);
 }
 
-/*
- * This static table uses ext_freq and vdd_io values to select suitable
- * PLL dividers m, n and p1 which have been calculated as specifiec in p36
- * of Aptina's mt9p031 datasheet. New values should be added here.
- */
-static const struct mt9p031_pll_divs mt9p031_divs[] = {
-	/* ext_freq	target_freq	m	n	p1 */
-	{21000000,	48000000,	26,	2,	6}
-};
-
-static int mt9p031_pll_get_divs(struct mt9p031 *mt9p031)
+static int mt9p031_pll_setup(struct mt9p031 *mt9p031)
 {
+	static const struct aptina_pll_limits limits = {
+		.ext_clock_min = 6000000,
+		.ext_clock_max = 27000000,
+		.int_clock_min = 2000000,
+		.int_clock_max = 13500000,
+		.out_clock_min = 180000000,
+		.out_clock_max = 360000000,
+		.pix_clock_max = 96000000,
+		.n_min = 1,
+		.n_max = 64,
+		.m_min = 16,
+		.m_max = 255,
+		.p1_min = 1,
+		.p1_max = 128,
+	};
+
 	struct i2c_client *client = v4l2_get_subdevdata(&mt9p031->subdev);
-	int i;
+	struct mt9p031_platform_data *pdata = mt9p031->pdata;
 
-	for (i = 0; i < ARRAY_SIZE(mt9p031_divs); i++) {
-		if (mt9p031_divs[i].ext_freq == mt9p031->pdata->ext_freq &&
-		  mt9p031_divs[i].target_freq == mt9p031->pdata->target_freq) {
-			mt9p031->pll = &mt9p031_divs[i];
-			return 0;
-		}
-	}
+	mt9p031->pll.ext_clock = pdata->ext_freq;
+	mt9p031->pll.pix_clock = pdata->target_freq;
 
-	dev_err(&client->dev, "Couldn't find PLL dividers for ext_freq = %d, "
-		"target_freq = %d\n", mt9p031->pdata->ext_freq,
-		mt9p031->pdata->target_freq);
-	return -EINVAL;
+	return aptina_pll_calculate(&client->dev, &limits, &mt9p031->pll);
 }
 
 static int mt9p031_pll_enable(struct mt9p031 *mt9p031)
@@ -223,11 +215,11 @@ static int mt9p031_pll_enable(struct mt9p031 *mt9p031)
 		return ret;
 
 	ret = mt9p031_write(client, MT9P031_PLL_CONFIG_1,
-			    (mt9p031->pll->m << 8) | (mt9p031->pll->n - 1));
+			    (mt9p031->pll.m << 8) | (mt9p031->pll.n - 1));
 	if (ret < 0)
 		return ret;
 
-	ret = mt9p031_write(client, MT9P031_PLL_CONFIG_2, mt9p031->pll->p1 - 1);
+	ret = mt9p031_write(client, MT9P031_PLL_CONFIG_2, mt9p031->pll.p1 - 1);
 	if (ret < 0)
 		return ret;
 
@@ -900,7 +892,7 @@ static int mt9p031_probe(struct i2c_client *client,
 	mt9p031->format.field = V4L2_FIELD_NONE;
 	mt9p031->format.colorspace = V4L2_COLORSPACE_SRGB;
 
-	ret = mt9p031_pll_get_divs(mt9p031);
+	ret = mt9p031_pll_setup(mt9p031);
 
 done:
 	if (ret < 0) {
-- 
1.7.3.4

[PATCH v3 5/5] v4l: Add driver for Micron MT9M032 camera sensor

[Laurent Pinchart]

From: Martin Hostettler <martin@neutronstar.dyndns.org>

The MT9M032 is a parallel 1.6MP sensor from Micron controlled through I2C.

The driver creates a V4L2 subdevice. It currently supports cropping, gain,
exposure and v/h flipping controls in monochrome mode with an
external pixel clock.

Signed-off-by: Martin Hostettler <martin@neutronstar.dyndns.org>
[Lots of clean up, fixes and enhancements]
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 drivers/media/video/Kconfig   |    8 +
 drivers/media/video/Makefile  |    1 +
 drivers/media/video/mt9m032.c |  825 +++++++++++++++++++++++++++++++++++++++++
 include/media/mt9m032.h       |   36 ++
 4 files changed, 870 insertions(+), 0 deletions(-)
 create mode 100644 drivers/media/video/mt9m032.c
 create mode 100644 include/media/mt9m032.h

diff --git a/drivers/media/video/Kconfig b/drivers/media/video/Kconfig
index 666836d..2611708 100644
--- a/drivers/media/video/Kconfig
+++ b/drivers/media/video/Kconfig
@@ -947,6 +947,14 @@ config SOC_CAMERA_MT9M001
 	  This driver supports MT9M001 cameras from Micron, monochrome
 	  and colour models.
 
+config VIDEO_MT9M032
+	tristate "MT9M032 camera sensor support"
+	depends on I2C && VIDEO_V4L2
+	select VIDEO_APTINA_PLL
+	help
+	  This driver supports MT9M032 cameras from Micron, monochrome
+	  models only.
+
 config SOC_CAMERA_MT9M111
 	tristate "mt9m111, mt9m112 and mt9m131 support"
 	depends on SOC_CAMERA && I2C
diff --git a/drivers/media/video/Makefile b/drivers/media/video/Makefile
index d1304e1..8e037e9 100644
--- a/drivers/media/video/Makefile
+++ b/drivers/media/video/Makefile
@@ -82,6 +82,7 @@ obj-$(CONFIG_VIDEO_AS3645A)	+= as3645a.o
 
 obj-$(CONFIG_SOC_CAMERA_IMX074)		+= imx074.o
 obj-$(CONFIG_SOC_CAMERA_MT9M001)	+= mt9m001.o
+obj-$(CONFIG_VIDEO_MT9M032)             += mt9m032.o
 obj-$(CONFIG_SOC_CAMERA_MT9M111)	+= mt9m111.o
 obj-$(CONFIG_SOC_CAMERA_MT9T031)	+= mt9t031.o
 obj-$(CONFIG_SOC_CAMERA_MT9T112)	+= mt9t112.o
diff --git a/drivers/media/video/mt9m032.c b/drivers/media/video/mt9m032.c
new file mode 100644
index 0000000..c3d69aa
--- /dev/null
+++ b/drivers/media/video/mt9m032.c
@@ -0,0 +1,825 @@
+/*
+ * Driver for MT9M032 CMOS Image Sensor from Micron
+ *
+ * Copyright (C) 2010-2011 Lund Engineering
+ * Contact: Gil Lund <gwlund@lundeng.com>
+ * Author: Martin Hostettler <martin@neutronstar.dyndns.org>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/math64.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/v4l2-mediabus.h>
+
+#include <media/media-entity.h>
+#include <media/mt9m032.h>
+#include <media/v4l2-ctrls.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-subdev.h>
+
+#include "aptina-pll.h"
+
+/*
+ * width and height include active boundary and black parts
+ *
+ * column    0-  15 active boundry
+ * column   16-1455 image
+ * column 1456-1471 active boundry
+ * column 1472-1599 black
+ *
+ * row       0-  51 black
+ * row      53-  59 active boundry
+ * row      60-1139 image
+ * row    1140-1147 active boundry
+ * row    1148-1151 black
+ */
+
+#define MT9M032_PIXEL_ARRAY_WIDTH			1600
+#define MT9M032_PIXEL_ARRAY_HEIGHT			1152
+
+#define MT9M032_CHIP_VERSION				0x00
+#define		MT9M032_CHIP_VERSION_VALUE		0x1402
+#define MT9M032_ROW_START				0x01
+#define		MT9M032_ROW_START_MIN			0
+#define		MT9M032_ROW_START_MAX			1152
+#define		MT9M032_ROW_START_DEF			60
+#define MT9M032_COLUMN_START				0x02
+#define		MT9M032_COLUMN_START_MIN		0
+#define		MT9M032_COLUMN_START_MAX		1600
+#define		MT9M032_COLUMN_START_DEF		16
+#define MT9M032_ROW_SIZE				0x03
+#define		MT9M032_ROW_SIZE_MIN			32
+#define		MT9M032_ROW_SIZE_MAX			1152
+#define		MT9M032_ROW_SIZE_DEF			1080
+#define MT9M032_COLUMN_SIZE				0x04
+#define		MT9M032_COLUMN_SIZE_MIN			32
+#define		MT9M032_COLUMN_SIZE_MAX			1600
+#define		MT9M032_COLUMN_SIZE_DEF			1440
+#define MT9M032_HBLANK					0x05
+#define MT9M032_VBLANK					0x06
+#define		MT9M032_VBLANK_MAX			0x7ff
+#define MT9M032_SHUTTER_WIDTH_HIGH			0x08
+#define MT9M032_SHUTTER_WIDTH_LOW			0x09
+#define		MT9M032_SHUTTER_WIDTH_MIN		1
+#define		MT9M032_SHUTTER_WIDTH_MAX		1048575
+#define		MT9M032_SHUTTER_WIDTH_DEF		1943
+#define MT9M032_PIX_CLK_CTRL				0x0a
+#define		MT9M032_PIX_CLK_CTRL_INV_PIXCLK		0x8000
+#define MT9M032_RESTART					0x0b
+#define MT9M032_RESET					0x0d
+#define MT9M032_PLL_CONFIG1				0x11
+#define		MT9M032_PLL_CONFIG1_OUTDIV_MASK		0x3f
+#define		MT9M032_PLL_CONFIG1_MUL_SHIFT		8
+#define MT9M032_READ_MODE1				0x1e
+#define MT9M032_READ_MODE2				0x20
+#define		MT9M032_READ_MODE2_VFLIP_SHIFT		15
+#define		MT9M032_READ_MODE2_HFLIP_SHIFT		14
+#define		MT9M032_READ_MODE2_ROW_BLC		0x40
+#define MT9M032_GAIN_GREEN1				0x2b
+#define MT9M032_GAIN_BLUE				0x2c
+#define MT9M032_GAIN_RED				0x2d
+#define MT9M032_GAIN_GREEN2				0x2e
+
+/* write only */
+#define MT9M032_GAIN_ALL				0x35
+#define		MT9M032_GAIN_DIGITAL_MASK		0x7f
+#define		MT9M032_GAIN_DIGITAL_SHIFT		8
+#define		MT9M032_GAIN_AMUL_SHIFT			6
+#define		MT9M032_GAIN_ANALOG_MASK		0x3f
+#define MT9M032_FORMATTER1				0x9e
+#define MT9M032_FORMATTER2				0x9f
+#define		MT9M032_FORMATTER2_DOUT_EN		0x1000
+#define		MT9M032_FORMATTER2_PIXCLK_EN		0x2000
+
+/*
+ * The available MT9M032 datasheet is missing documentation for register 0x10
+ * MT9P031 seems to be close enough, so use constants from that datasheet for
+ * now.
+ * But keep the name MT9P031 to remind us, that this isn't really confirmed
+ * for this sensor.
+ */
+#define MT9P031_PLL_CONTROL				0x10
+#define		MT9P031_PLL_CONTROL_PWROFF		0x0050
+#define		MT9P031_PLL_CONTROL_PWRON		0x0051
+#define		MT9P031_PLL_CONTROL_USEPLL		0x0052
+#define MT9P031_PLL_CONFIG2				0x11
+#define		MT9P031_PLL_CONFIG2_P1_DIV_MASK		0x1f
+
+struct mt9m032 {
+	struct v4l2_subdev subdev;
+	struct media_pad pad;
+	struct mt9m032_platform_data *pdata;
+
+	struct v4l2_ctrl_handler ctrls;
+	struct {
+		struct v4l2_ctrl *hflip;
+		struct v4l2_ctrl *vflip;
+	};
+
+	bool streaming;
+
+	unsigned int pix_clock;
+
+	struct v4l2_mbus_framefmt format;
+	struct v4l2_rect crop;
+	struct v4l2_fract frame_interval;
+};
+
+#define to_mt9m032(sd)	container_of(sd, struct mt9m032, subdev)
+#define to_dev(sensor) \
+	(&((struct i2c_client *)v4l2_get_subdevdata(&(sensor)->subdev))->dev)
+
+static int mt9m032_read(struct i2c_client *client, u8 reg)
+{
+	return i2c_smbus_read_word_swapped(client, reg);
+}
+
+static int mt9m032_write(struct i2c_client *client, u8 reg, const u16 data)
+{
+	return i2c_smbus_write_word_swapped(client, reg, data);
+}
+
+static u32 mt9m032_row_time(struct mt9m032 *sensor, unsigned int width)
+{
+	unsigned int effective_width;
+	u32 ns;
+
+	effective_width = width + 716; /* emperical value */
+	ns = div_u64(1000000000ULL * effective_width, sensor->pix_clock);
+	dev_dbg(to_dev(sensor),	"MT9M032 line time: %u ns\n", ns);
+	return ns;
+}
+
+static int mt9m032_update_timing(struct mt9m032 *sensor,
+				 struct v4l2_fract *interval)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&sensor->subdev);
+	struct v4l2_rect *crop = &sensor->crop;
+	unsigned int min_vblank;
+	unsigned int vblank;
+	u32 row_time;
+
+	if (!interval)
+		interval = &sensor->frame_interval;
+
+	row_time = mt9m032_row_time(sensor, crop->width);
+
+	vblank = div_u64(1000000000ULL * interval->numerator,
+			 (u64)row_time * interval->denominator)
+	       - crop->height;
+
+	if (vblank > MT9M032_VBLANK_MAX) {
+		/* hardware limits to 11 bit values */
+		interval->denominator = 1000;
+		interval->numerator =
+			div_u64((crop->height + MT9M032_VBLANK_MAX) *
+				(u64)row_time * interval->denominator,
+				1000000000ULL);
+		vblank = div_u64(1000000000ULL * interval->numerator,
+				 (u64)row_time * interval->denominator)
+		       - crop->height;
+	}
+	/* enforce minimal 1.6ms blanking time. */
+	min_vblank = 1600000 / row_time;
+	vblank = clamp_t(unsigned int, vblank, min_vblank, MT9M032_VBLANK_MAX);
+
+	return mt9m032_write(client, MT9M032_VBLANK, vblank);
+}
+
+static int mt9m032_update_geom_timing(struct mt9m032 *sensor)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&sensor->subdev);
+	int ret;
+
+	ret = mt9m032_write(client, MT9M032_COLUMN_SIZE,
+			    sensor->crop.width - 1);
+	if (!ret)
+		ret = mt9m032_write(client, MT9M032_ROW_SIZE,
+				    sensor->crop.height - 1);
+	if (!ret)
+		ret = mt9m032_write(client, MT9M032_COLUMN_START,
+				    sensor->crop.left);
+	if (!ret)
+		ret = mt9m032_write(client, MT9M032_ROW_START,
+				    sensor->crop.top);
+	if (!ret)
+		ret = mt9m032_update_timing(sensor, NULL);
+	return ret;
+}
+
+static int update_formatter2(struct mt9m032 *sensor, bool streaming)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&sensor->subdev);
+	u16 reg_val =   MT9M032_FORMATTER2_DOUT_EN
+		      | 0x0070;  /* parts reserved! */
+				 /* possibly for changing to 14-bit mode */
+
+	if (streaming)
+		reg_val |= MT9M032_FORMATTER2_PIXCLK_EN;   /* pixclock enable */
+
+	return mt9m032_write(client, MT9M032_FORMATTER2, reg_val);
+}
+
+static int mt9m032_setup_pll(struct mt9m032 *sensor)
+{
+	static const struct aptina_pll_limits limits = {
+		.ext_clock_min = 8000000,
+		.ext_clock_max = 16500000,
+		.int_clock_min = 2000000,
+		.int_clock_max = 24000000,
+		.out_clock_min = 322000000,
+		.out_clock_max = 693000000,
+		.pix_clock_max = 99000000,
+		.n_min = 1,
+		.n_max = 64,
+		.m_min = 16,
+		.m_max = 255,
+		.p1_min = 1,
+		.p1_max = 128,
+	};
+
+	struct i2c_client *client = v4l2_get_subdevdata(&sensor->subdev);
+	struct mt9m032_platform_data *pdata = sensor->pdata;
+	struct aptina_pll pll;
+	int ret;
+
+	pll.ext_clock = pdata->ext_clock;
+	pll.pix_clock = pdata->pix_clock;
+
+	ret = aptina_pll_calculate(&client->dev, &limits, &pll);
+	if (ret < 0)
+		return ret;
+
+	sensor->pix_clock = pll.pix_clock;
+
+	ret = mt9m032_write(client, MT9M032_PLL_CONFIG1,
+			    (pll.m << MT9M032_PLL_CONFIG1_MUL_SHIFT)
+			    | (pll.p1 - 1));
+	if (!ret)
+		ret = mt9m032_write(client, MT9P031_PLL_CONFIG2, pll.n - 1);
+	if (!ret)
+		ret = mt9m032_write(client, MT9P031_PLL_CONTROL,
+				    MT9P031_PLL_CONTROL_PWRON |
+				    MT9P031_PLL_CONTROL_USEPLL);
+	if (!ret)		/* more reserved, Continuous, Master Mode */
+		ret = mt9m032_write(client, MT9M032_READ_MODE1, 0x8006);
+	if (!ret)		/* Set 14-bit mode, select 7 divider */
+		ret = mt9m032_write(client, MT9M032_FORMATTER1, 0x111e);
+
+	return ret;
+}
+
+/* -----------------------------------------------------------------------------
+ * Subdev pad operations
+ */
+
+static int mt9m032_enum_mbus_code(struct v4l2_subdev *subdev,
+				  struct v4l2_subdev_fh *fh,
+				  struct v4l2_subdev_mbus_code_enum *code)
+{
+	if (code->index != 0)
+		return -EINVAL;
+
+	code->code = V4L2_MBUS_FMT_Y8_1X8;
+	return 0;
+}
+
+static int mt9m032_enum_frame_size(struct v4l2_subdev *subdev,
+				   struct v4l2_subdev_fh *fh,
+				   struct v4l2_subdev_frame_size_enum *fse)
+{
+	if (fse->index != 0 || fse->code != V4L2_MBUS_FMT_Y8_1X8)
+		return -EINVAL;
+
+	fse->min_width = MT9M032_COLUMN_SIZE_DEF;
+	fse->max_width = MT9M032_COLUMN_SIZE_DEF;
+	fse->min_height = MT9M032_ROW_SIZE_DEF;
+	fse->max_height = MT9M032_ROW_SIZE_DEF;
+
+	return 0;
+}
+
+/**
+ * __mt9m032_get_pad_crop() - get crop rect
+ * @sensor: pointer to the sensor struct
+ * @fh: filehandle for getting the try crop rect from
+ * @which: select try or active crop rect
+ *
+ * Returns a pointer the current active or fh relative try crop rect
+ */
+static struct v4l2_rect *
+__mt9m032_get_pad_crop(struct mt9m032 *sensor, struct v4l2_subdev_fh *fh,
+		       enum v4l2_subdev_format_whence which)
+{
+	switch (which) {
+	case V4L2_SUBDEV_FORMAT_TRY:
+		return v4l2_subdev_get_try_crop(fh, 0);
+	case V4L2_SUBDEV_FORMAT_ACTIVE:
+		return &sensor->crop;
+	default:
+		return NULL;
+	}
+}
+
+/**
+ * __mt9m032_get_pad_format() - get format
+ * @sensor: pointer to the sensor struct
+ * @fh: filehandle for getting the try format from
+ * @which: select try or active format
+ *
+ * Returns a pointer the current active or fh relative try format
+ */
+static struct v4l2_mbus_framefmt *
+__mt9m032_get_pad_format(struct mt9m032 *sensor, struct v4l2_subdev_fh *fh,
+			 enum v4l2_subdev_format_whence which)
+{
+	switch (which) {
+	case V4L2_SUBDEV_FORMAT_TRY:
+		return v4l2_subdev_get_try_format(fh, 0);
+	case V4L2_SUBDEV_FORMAT_ACTIVE:
+		return &sensor->format;
+	default:
+		return NULL;
+	}
+}
+
+static int mt9m032_get_pad_format(struct v4l2_subdev *subdev,
+				  struct v4l2_subdev_fh *fh,
+				  struct v4l2_subdev_format *fmt)
+{
+	struct mt9m032 *sensor = to_mt9m032(subdev);
+
+	fmt->format = *__mt9m032_get_pad_format(sensor, fh, fmt->which);
+	return 0;
+}
+
+static int mt9m032_set_pad_format(struct v4l2_subdev *subdev,
+				  struct v4l2_subdev_fh *fh,
+				  struct v4l2_subdev_format *fmt)
+{
+	struct mt9m032 *sensor = to_mt9m032(subdev);
+
+	if (sensor->streaming && fmt->which == V4L2_SUBDEV_FORMAT_ACTIVE)
+		return -EBUSY;
+
+	/* Scaling is not supported, the format is thus fixed. */
+	return mt9m032_get_pad_format(subdev, fh, fmt);
+}
+
+static int mt9m032_get_crop(struct v4l2_subdev *subdev,
+			    struct v4l2_subdev_fh *fh,
+			    struct v4l2_subdev_crop *crop)
+{
+	struct mt9m032 *sensor = to_mt9m032(subdev);
+
+	crop->rect = *__mt9m032_get_pad_crop(sensor, fh, crop->which);
+
+	return 0;
+}
+
+static int mt9m032_set_crop(struct v4l2_subdev *subdev,
+			    struct v4l2_subdev_fh *fh,
+			    struct v4l2_subdev_crop *crop)
+{
+	struct mt9m032 *sensor = to_mt9m032(subdev);
+	struct v4l2_mbus_framefmt *format;
+	struct v4l2_rect *__crop;
+	struct v4l2_rect rect;
+
+	if (sensor->streaming && crop->which == V4L2_SUBDEV_FORMAT_ACTIVE)
+		return -EBUSY;
+
+	/* Clamp the crop rectangle boundaries and align them to a multiple of 2
+	 * pixels to ensure a GRBG Bayer pattern.
+	 */
+	rect.left = clamp(ALIGN(crop->rect.left, 2), MT9M032_COLUMN_START_MIN,
+			  MT9M032_COLUMN_START_MAX);
+	rect.top = clamp(ALIGN(crop->rect.top, 2), MT9M032_ROW_START_MIN,
+			 MT9M032_ROW_START_MAX);
+	rect.width = clamp(ALIGN(crop->rect.width, 2), MT9M032_COLUMN_SIZE_MIN,
+			   MT9M032_COLUMN_SIZE_MAX);
+	rect.height = clamp(ALIGN(crop->rect.height, 2), MT9M032_ROW_SIZE_MIN,
+			    MT9M032_ROW_SIZE_MAX);
+
+	rect.width = min(rect.width, MT9M032_PIXEL_ARRAY_WIDTH - rect.left);
+	rect.height = min(rect.height, MT9M032_PIXEL_ARRAY_HEIGHT - rect.top);
+
+	__crop = __mt9m032_get_pad_crop(sensor, fh, crop->which);
+
+	if (rect.width != __crop->width || rect.height != __crop->height) {
+		/* Reset the output image size if the crop rectangle size has
+		 * been modified.
+		 */
+		format = __mt9m032_get_pad_format(sensor, fh, crop->which);
+		format->width = rect.width;
+		format->height = rect.height;
+	}
+
+	*__crop = rect;
+	crop->rect = rect;
+
+	if (crop->which != V4L2_SUBDEV_FORMAT_ACTIVE)
+		return 0;
+
+	return mt9m032_update_geom_timing(sensor);
+}
+
+static int mt9m032_get_frame_interval(struct v4l2_subdev *subdev,
+				      struct v4l2_subdev_frame_interval *fi)
+{
+	struct mt9m032 *sensor = to_mt9m032(subdev);
+
+	memset(fi, 0, sizeof(*fi));
+	fi->interval = sensor->frame_interval;
+
+	return 0;
+}
+
+static int mt9m032_set_frame_interval(struct v4l2_subdev *subdev,
+				      struct v4l2_subdev_frame_interval *fi)
+{
+	struct mt9m032 *sensor = to_mt9m032(subdev);
+	int ret;
+
+	if (sensor->streaming)
+		return -EBUSY;
+
+	memset(fi->reserved, 0, sizeof(fi->reserved));
+
+	ret = mt9m032_update_timing(sensor, &fi->interval);
+	if (!ret)
+		sensor->frame_interval = fi->interval;
+
+	return ret;
+}
+
+static int mt9m032_s_stream(struct v4l2_subdev *subdev, int streaming)
+{
+	struct mt9m032 *sensor = to_mt9m032(subdev);
+	int ret;
+
+	ret = update_formatter2(sensor, streaming);
+	if (!ret)
+		sensor->streaming = streaming;
+	return ret;
+}
+
+/* -----------------------------------------------------------------------------
+ * V4L2 subdev core operations
+ */
+
+#ifdef CONFIG_VIDEO_ADV_DEBUG
+static int mt9m032_g_register(struct v4l2_subdev *sd,
+			      struct v4l2_dbg_register *reg)
+{
+	struct mt9m032 *sensor = to_mt9m032(sd);
+	struct i2c_client *client = v4l2_get_subdevdata(&sensor->subdev);
+	int val;
+
+	if (reg->match.type != V4L2_CHIP_MATCH_I2C_ADDR || reg->reg > 0xff)
+		return -EINVAL;
+	if (reg->match.addr != client->addr)
+		return -ENODEV;
+
+	val = mt9m032_read(client, reg->reg);
+	if (val < 0)
+		return -EIO;
+
+	reg->size = 2;
+	reg->val = val;
+
+	return 0;
+}
+
+static int mt9m032_s_register(struct v4l2_subdev *sd,
+			      struct v4l2_dbg_register *reg)
+{
+	struct mt9m032 *sensor = to_mt9m032(sd);
+	struct i2c_client *client = v4l2_get_subdevdata(&sensor->subdev);
+
+	if (reg->match.type != V4L2_CHIP_MATCH_I2C_ADDR || reg->reg > 0xff)
+		return -EINVAL;
+
+	if (reg->match.addr != client->addr)
+		return -ENODEV;
+
+	return mt9m032_write(client, reg->reg, reg->val);
+}
+#endif
+
+/* -----------------------------------------------------------------------------
+ * V4L2 subdev control operations
+ */
+
+static int update_read_mode2(struct mt9m032 *sensor, bool vflip, bool hflip)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&sensor->subdev);
+	int reg_val = (!!vflip) << MT9M032_READ_MODE2_VFLIP_SHIFT
+		    | (!!hflip) << MT9M032_READ_MODE2_HFLIP_SHIFT
+		    | MT9M032_READ_MODE2_ROW_BLC
+		    | 0x0007;
+
+	return mt9m032_write(client, MT9M032_READ_MODE2, reg_val);
+}
+
+static int mt9m032_set_gain(struct mt9m032 *sensor, s32 val)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&sensor->subdev);
+	int digital_gain_val;	/* in 1/8th (0..127) */
+	int analog_mul;		/* 0 or 1 */
+	int analog_gain_val;	/* in 1/16th. (0..63) */
+	u16 reg_val;
+
+	digital_gain_val = 51; /* from setup example */
+
+	if (val < 63) {
+		analog_mul = 0;
+		analog_gain_val = val;
+	} else {
+		analog_mul = 1;
+		analog_gain_val = val / 2;
+	}
+
+	/* a_gain = (1+analog_mul) + (analog_gain_val+1)/16 */
+	/* overall_gain = a_gain * (1 + digital_gain_val / 8) */
+
+	reg_val = ((digital_gain_val & MT9M032_GAIN_DIGITAL_MASK)
+		   << MT9M032_GAIN_DIGITAL_SHIFT)
+		| ((analog_mul & 1) << MT9M032_GAIN_AMUL_SHIFT)
+		| (analog_gain_val & MT9M032_GAIN_ANALOG_MASK);
+
+	return mt9m032_write(client, MT9M032_GAIN_ALL, reg_val);
+}
+
+static int mt9m032_try_ctrl(struct v4l2_ctrl *ctrl)
+{
+	if (ctrl->id == V4L2_CID_GAIN && ctrl->val >= 63) {
+		/* round because of multiplier used for values >= 63 */
+		ctrl->val &= ~1;
+	}
+
+	return 0;
+}
+
+static int mt9m032_set_ctrl(struct v4l2_ctrl *ctrl)
+{
+	struct mt9m032 *sensor =
+		container_of(ctrl->handler, struct mt9m032, ctrls);
+	struct i2c_client *client = v4l2_get_subdevdata(&sensor->subdev);
+	int ret;
+
+	switch (ctrl->id) {
+	case V4L2_CID_GAIN:
+		return mt9m032_set_gain(sensor, ctrl->val);
+
+	case V4L2_CID_HFLIP:
+	case V4L2_CID_VFLIP:
+		return update_read_mode2(sensor, sensor->vflip->val,
+					 sensor->hflip->val);
+
+	case V4L2_CID_EXPOSURE:
+		ret = mt9m032_write(client, MT9M032_SHUTTER_WIDTH_HIGH,
+				    (ctrl->val >> 16) & 0xffff);
+		if (ret < 0)
+			return ret;
+
+		return mt9m032_write(client, MT9M032_SHUTTER_WIDTH_LOW,
+				     ctrl->val & 0xffff);
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static struct v4l2_ctrl_ops mt9m032_ctrl_ops = {
+	.s_ctrl = mt9m032_set_ctrl,
+	.try_ctrl = mt9m032_try_ctrl,
+};
+
+/* -------------------------------------------------------------------------- */
+
+static const struct v4l2_subdev_core_ops mt9m032_core_ops = {
+#ifdef CONFIG_VIDEO_ADV_DEBUG
+	.g_register = mt9m032_g_register,
+	.s_register = mt9m032_s_register,
+#endif
+};
+
+static const struct v4l2_subdev_video_ops mt9m032_video_ops = {
+	.s_stream = mt9m032_s_stream,
+	.g_frame_interval = mt9m032_get_frame_interval,
+	.s_frame_interval = mt9m032_set_frame_interval,
+};
+
+static const struct v4l2_subdev_pad_ops mt9m032_pad_ops = {
+	.enum_mbus_code = mt9m032_enum_mbus_code,
+	.enum_frame_size = mt9m032_enum_frame_size,
+	.get_fmt = mt9m032_get_pad_format,
+	.set_fmt = mt9m032_set_pad_format,
+	.set_crop = mt9m032_set_crop,
+	.get_crop = mt9m032_get_crop,
+};
+
+static const struct v4l2_subdev_ops mt9m032_ops = {
+	.core = &mt9m032_core_ops,
+	.video = &mt9m032_video_ops,
+	.pad = &mt9m032_pad_ops,
+};
+
+/* -----------------------------------------------------------------------------
+ * Driver initialization and probing
+ */
+
+static int mt9m032_probe(struct i2c_client *client,
+			 const struct i2c_device_id *devid)
+{
+	struct i2c_adapter *adapter = client->adapter;
+	struct mt9m032 *sensor;
+	int chip_version;
+	int ret;
+
+	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA)) {
+		dev_warn(&client->dev,
+			 "I2C-Adapter doesn't support I2C_FUNC_SMBUS_WORD\n");
+		return -EIO;
+	}
+
+	if (!client->dev.platform_data)
+		return -ENODEV;
+
+	sensor = kzalloc(sizeof(*sensor), GFP_KERNEL);
+	if (sensor == NULL)
+		return -ENOMEM;
+
+	sensor->pdata = client->dev.platform_data;
+
+	v4l2_i2c_subdev_init(&sensor->subdev, client, &mt9m032_ops);
+	sensor->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
+
+	chip_version = mt9m032_read(client, MT9M032_CHIP_VERSION);
+	if (chip_version != MT9M032_CHIP_VERSION_VALUE) {
+		dev_err(&client->dev, "MT9M032 not detected, wrong version "
+			"0x%04x\n", chip_version);
+		ret = -ENODEV;
+		goto free_sensor;
+	}
+
+	dev_info(&client->dev, "MT9P031 detected at address 0x%02x\n",
+		 client->addr);
+
+	sensor->frame_interval.numerator = 1;
+	sensor->frame_interval.denominator = 30;
+
+	sensor->crop.left = 416;
+	sensor->crop.top = 360;
+	sensor->crop.width = 640;
+	sensor->crop.height = 480;
+
+	sensor->format.width = sensor->crop.width;
+	sensor->format.height = sensor->crop.height;
+	sensor->format.code = V4L2_MBUS_FMT_Y8_1X8;
+	sensor->format.field = V4L2_FIELD_NONE;
+	sensor->format.colorspace = V4L2_COLORSPACE_SRGB;
+
+	v4l2_ctrl_handler_init(&sensor->ctrls, 4);
+
+	v4l2_ctrl_new_std(&sensor->ctrls, &mt9m032_ctrl_ops,
+			  V4L2_CID_GAIN, 0, 127, 1, 64);
+
+	sensor->hflip = v4l2_ctrl_new_std(&sensor->ctrls,
+					  &mt9m032_ctrl_ops,
+					  V4L2_CID_HFLIP, 0, 1, 1, 0);
+	sensor->vflip = v4l2_ctrl_new_std(&sensor->ctrls,
+					  &mt9m032_ctrl_ops,
+					  V4L2_CID_VFLIP, 0, 1, 1, 0);
+
+	v4l2_ctrl_new_std(&sensor->ctrls, &mt9m032_ctrl_ops,
+			  V4L2_CID_EXPOSURE, MT9M032_SHUTTER_WIDTH_MIN,
+			  MT9M032_SHUTTER_WIDTH_MAX, 1,
+			  MT9M032_SHUTTER_WIDTH_DEF);
+
+	if (sensor->ctrls.error) {
+		ret = sensor->ctrls.error;
+		dev_err(&client->dev, "control initialization error %d\n", ret);
+		goto free_ctrl;
+	}
+
+	v4l2_ctrl_cluster(2, &sensor->hflip);
+
+	sensor->subdev.ctrl_handler = &sensor->ctrls;
+	sensor->pad.flags = MEDIA_PAD_FL_SOURCE;
+	ret = media_entity_init(&sensor->subdev.entity, 1, &sensor->pad, 0);
+	if (ret < 0)
+		goto free_ctrl;
+
+	ret = mt9m032_write(client, MT9M032_RESET, 1);	/* reset on */
+	if (ret < 0)
+		goto free_ctrl;
+	mt9m032_write(client, MT9M032_RESET, 0);	/* reset off */
+	if (ret < 0)
+		goto free_ctrl;
+
+	ret = mt9m032_setup_pll(sensor);
+	if (ret < 0)
+		goto free_ctrl;
+	usleep_range(10000, 11000);
+
+	v4l2_ctrl_handler_setup(&sensor->ctrls);
+
+	/* SIZE */
+	ret = mt9m032_update_geom_timing(sensor);
+	if (ret < 0)
+		goto free_ctrl;
+
+	ret = mt9m032_write(client, 0x41, 0x0000);	/* reserved !!! */
+	if (ret < 0)
+		goto free_ctrl;
+	ret = mt9m032_write(client, 0x42, 0x0003);	/* reserved !!! */
+	if (ret < 0)
+		goto free_ctrl;
+	ret = mt9m032_write(client, 0x43, 0x0003);	/* reserved !!! */
+	if (ret < 0)
+		goto free_ctrl;
+	ret = mt9m032_write(client, 0x7f, 0x0000);	/* reserved !!! */
+	if (ret < 0)
+		goto free_ctrl;
+	if (sensor->pdata->invert_pixclock) {
+		ret = mt9m032_write(client, MT9M032_PIX_CLK_CTRL,
+				    MT9M032_PIX_CLK_CTRL_INV_PIXCLK);
+		if (ret < 0)
+			goto free_ctrl;
+	}
+
+	ret = mt9m032_write(client, MT9M032_RESTART, 1); /* Restart on */
+	if (ret < 0)
+		goto free_ctrl;
+	msleep(100);
+	ret = mt9m032_write(client, MT9M032_RESTART, 0); /* Restart off */
+	if (ret < 0)
+		goto free_ctrl;
+	msleep(100);
+	ret = update_formatter2(sensor, false);
+	if (ret < 0)
+		goto free_ctrl;
+
+	return ret;
+
+free_ctrl:
+	v4l2_ctrl_handler_free(&sensor->ctrls);
+
+free_sensor:
+	kfree(sensor);
+	return ret;
+}
+
+static int mt9m032_remove(struct i2c_client *client)
+{
+	struct v4l2_subdev *subdev = i2c_get_clientdata(client);
+	struct mt9m032 *sensor = to_mt9m032(subdev);
+
+	v4l2_device_unregister_subdev(&sensor->subdev);
+	v4l2_ctrl_handler_free(&sensor->ctrls);
+	media_entity_cleanup(&sensor->subdev.entity);
+	kfree(sensor);
+	return 0;
+}
+
+static const struct i2c_device_id mt9m032_id_table[] = {
+	{ MT9M032_NAME, 0 },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(i2c, mt9m032_id_table);
+
+static struct i2c_driver mt9m032_i2c_driver = {
+	.driver = {
+		.name = MT9M032_NAME,
+	},
+	.probe = mt9m032_probe,
+	.remove = mt9m032_remove,
+	.id_table = mt9m032_id_table,
+};
+
+module_i2c_driver(mt9m032_i2c_driver);
+
+MODULE_AUTHOR("Martin Hostettler <martin@neutronstar.dyndns.org>");
+MODULE_DESCRIPTION("MT9M032 camera sensor driver");
+MODULE_LICENSE("GPL v2");
diff --git a/include/media/mt9m032.h b/include/media/mt9m032.h
new file mode 100644
index 0000000..c3a7811
--- /dev/null
+++ b/include/media/mt9m032.h
@@ -0,0 +1,36 @@
+/*
+ * Driver for MT9M032 CMOS Image Sensor from Micron
+ *
+ * Copyright (C) 2010-2011 Lund Engineering
+ * Contact: Gil Lund <gwlund@lundeng.com>
+ * Author: Martin Hostettler <martin@neutronstar.dyndns.org>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ *
+ */
+
+#ifndef MT9M032_H
+#define MT9M032_H
+
+#define MT9M032_NAME		"mt9m032"
+#define MT9M032_I2C_ADDR	(0xb8 >> 1)
+
+struct mt9m032_platform_data {
+	u32 ext_clock;
+	u32 pix_clock;
+	bool invert_pixclock;
+
+};
+#endif /* MT9M032_H */
-- 
1.7.3.4

Re: [PATCH v3 2/5] mt9p031: Remove unused xskip and yskip fields in struct mt9p031

[Sakari Ailus]

Hi Laurent,

Thanks for the patch.

Laurent Pinchart wrote:
> The fields are set but never used, remove them.
> 
> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> ---
>  drivers/media/video/mt9p031.c |    4 ----
>  1 files changed, 0 insertions(+), 4 deletions(-)

Reviewed-by: Sakari Ailus <sakari.ailus@iki.fi>

-- 
Sakari Ailus
sakari.ailus@iki.fi

Re: [PATCH v3 4/5] mt9p031: Use generic PLL setup code

[Sakari Ailus]

Thanks for the patch, Laurent!

Laurent Pinchart wrote:
> Compute the PLL parameters at runtime using the generic Aptina PLL
> helper.
> 
> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> ---
>  drivers/media/video/Kconfig   |    1 +
>  drivers/media/video/mt9p031.c |   62 ++++++++++++++++++-----------------------
>  2 files changed, 28 insertions(+), 35 deletions(-)

Acked-by: Sakari Ailus <sakari.ailus@iki.fi>

-- 
Sakari Ailus
sakari.ailus@iki.fi

Re: [PATCH v3 5/5] v4l: Add driver for Micron MT9M032 camera sensor

[Sakari Ailus]

Hi Laurent,

Thanks for the patch.

I have a few comments below. Just one fairly general question: locking.
Shouldn't you serialise accesses to sensor registers and your data,
possibly by using a mutex?

Laurent Pinchart wrote:
> From: Martin Hostettler <martin@neutronstar.dyndns.org>
> 
> The MT9M032 is a parallel 1.6MP sensor from Micron controlled through I2C.
> 
> The driver creates a V4L2 subdevice. It currently supports cropping, gain,
> exposure and v/h flipping controls in monochrome mode with an
> external pixel clock.
> 
> Signed-off-by: Martin Hostettler <martin@neutronstar.dyndns.org>
> [Lots of clean up, fixes and enhancements]
> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> ---
>  drivers/media/video/Kconfig   |    8 +
>  drivers/media/video/Makefile  |    1 +
>  drivers/media/video/mt9m032.c |  825 +++++++++++++++++++++++++++++++++++++++++
>  include/media/mt9m032.h       |   36 ++
>  4 files changed, 870 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/media/video/mt9m032.c
>  create mode 100644 include/media/mt9m032.h
> 
> diff --git a/drivers/media/video/Kconfig b/drivers/media/video/Kconfig
> index 666836d..2611708 100644
> --- a/drivers/media/video/Kconfig
> +++ b/drivers/media/video/Kconfig
> @@ -947,6 +947,14 @@ config SOC_CAMERA_MT9M001
>  	  This driver supports MT9M001 cameras from Micron, monochrome
>  	  and colour models.
>  
> +config VIDEO_MT9M032
> +	tristate "MT9M032 camera sensor support"
> +	depends on I2C && VIDEO_V4L2
> +	select VIDEO_APTINA_PLL
> +	help
> +	  This driver supports MT9M032 cameras from Micron, monochrome
> +	  models only.
> +
>  config SOC_CAMERA_MT9M111
>  	tristate "mt9m111, mt9m112 and mt9m131 support"
>  	depends on SOC_CAMERA && I2C
> diff --git a/drivers/media/video/Makefile b/drivers/media/video/Makefile
> index d1304e1..8e037e9 100644
> --- a/drivers/media/video/Makefile
> +++ b/drivers/media/video/Makefile
> @@ -82,6 +82,7 @@ obj-$(CONFIG_VIDEO_AS3645A)	+= as3645a.o
>  
>  obj-$(CONFIG_SOC_CAMERA_IMX074)		+= imx074.o
>  obj-$(CONFIG_SOC_CAMERA_MT9M001)	+= mt9m001.o
> +obj-$(CONFIG_VIDEO_MT9M032)             += mt9m032.o

I would put this among the other subdev sensor drivers instead.

>  obj-$(CONFIG_SOC_CAMERA_MT9M111)	+= mt9m111.o
>  obj-$(CONFIG_SOC_CAMERA_MT9T031)	+= mt9t031.o
>  obj-$(CONFIG_SOC_CAMERA_MT9T112)	+= mt9t112.o
> diff --git a/drivers/media/video/mt9m032.c b/drivers/media/video/mt9m032.c
> new file mode 100644
> index 0000000..c3d69aa
> --- /dev/null
> +++ b/drivers/media/video/mt9m032.c
> @@ -0,0 +1,825 @@
> +/*
> + * Driver for MT9M032 CMOS Image Sensor from Micron
> + *
> + * Copyright (C) 2010-2011 Lund Engineering
> + * Contact: Gil Lund <gwlund@lundeng.com>
> + * Author: Martin Hostettler <martin@neutronstar.dyndns.org>
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License
> + * version 2 as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful, but
> + * WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
> + * 02110-1301 USA
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/i2c.h>
> +#include <linux/init.h>
> +#include <linux/kernel.h>
> +#include <linux/math64.h>
> +#include <linux/module.h>
> +#include <linux/slab.h>
> +#include <linux/v4l2-mediabus.h>
> +
> +#include <media/media-entity.h>
> +#include <media/mt9m032.h>
> +#include <media/v4l2-ctrls.h>
> +#include <media/v4l2-device.h>
> +#include <media/v4l2-subdev.h>
> +
> +#include "aptina-pll.h"
> +
> +/*
> + * width and height include active boundary and black parts
> + *
> + * column    0-  15 active boundry
> + * column   16-1455 image
> + * column 1456-1471 active boundry
> + * column 1472-1599 black
> + *
> + * row       0-  51 black
> + * row      53-  59 active boundry
> + * row      60-1139 image
> + * row    1140-1147 active boundry
> + * row    1148-1151 black
> + */
> +
> +#define MT9M032_PIXEL_ARRAY_WIDTH			1600
> +#define MT9M032_PIXEL_ARRAY_HEIGHT			1152
> +
> +#define MT9M032_CHIP_VERSION				0x00
> +#define		MT9M032_CHIP_VERSION_VALUE		0x1402
> +#define MT9M032_ROW_START				0x01
> +#define		MT9M032_ROW_START_MIN			0
> +#define		MT9M032_ROW_START_MAX			1152
> +#define		MT9M032_ROW_START_DEF			60
> +#define MT9M032_COLUMN_START				0x02
> +#define		MT9M032_COLUMN_START_MIN		0
> +#define		MT9M032_COLUMN_START_MAX		1600
> +#define		MT9M032_COLUMN_START_DEF		16
> +#define MT9M032_ROW_SIZE				0x03
> +#define		MT9M032_ROW_SIZE_MIN			32
> +#define		MT9M032_ROW_SIZE_MAX			1152
> +#define		MT9M032_ROW_SIZE_DEF			1080
> +#define MT9M032_COLUMN_SIZE				0x04
> +#define		MT9M032_COLUMN_SIZE_MIN			32
> +#define		MT9M032_COLUMN_SIZE_MAX			1600
> +#define		MT9M032_COLUMN_SIZE_DEF			1440
> +#define MT9M032_HBLANK					0x05
> +#define MT9M032_VBLANK					0x06
> +#define		MT9M032_VBLANK_MAX			0x7ff
> +#define MT9M032_SHUTTER_WIDTH_HIGH			0x08
> +#define MT9M032_SHUTTER_WIDTH_LOW			0x09
> +#define		MT9M032_SHUTTER_WIDTH_MIN		1
> +#define		MT9M032_SHUTTER_WIDTH_MAX		1048575
> +#define		MT9M032_SHUTTER_WIDTH_DEF		1943
> +#define MT9M032_PIX_CLK_CTRL				0x0a
> +#define		MT9M032_PIX_CLK_CTRL_INV_PIXCLK		0x8000
> +#define MT9M032_RESTART					0x0b
> +#define MT9M032_RESET					0x0d
> +#define MT9M032_PLL_CONFIG1				0x11
> +#define		MT9M032_PLL_CONFIG1_OUTDIV_MASK		0x3f
> +#define		MT9M032_PLL_CONFIG1_MUL_SHIFT		8
> +#define MT9M032_READ_MODE1				0x1e
> +#define MT9M032_READ_MODE2				0x20
> +#define		MT9M032_READ_MODE2_VFLIP_SHIFT		15
> +#define		MT9M032_READ_MODE2_HFLIP_SHIFT		14
> +#define		MT9M032_READ_MODE2_ROW_BLC		0x40
> +#define MT9M032_GAIN_GREEN1				0x2b
> +#define MT9M032_GAIN_BLUE				0x2c
> +#define MT9M032_GAIN_RED				0x2d
> +#define MT9M032_GAIN_GREEN2				0x2e
> +
> +/* write only */
> +#define MT9M032_GAIN_ALL				0x35
> +#define		MT9M032_GAIN_DIGITAL_MASK		0x7f
> +#define		MT9M032_GAIN_DIGITAL_SHIFT		8
> +#define		MT9M032_GAIN_AMUL_SHIFT			6
> +#define		MT9M032_GAIN_ANALOG_MASK		0x3f
> +#define MT9M032_FORMATTER1				0x9e
> +#define MT9M032_FORMATTER2				0x9f
> +#define		MT9M032_FORMATTER2_DOUT_EN		0x1000
> +#define		MT9M032_FORMATTER2_PIXCLK_EN		0x2000
> +
> +/*
> + * The available MT9M032 datasheet is missing documentation for register 0x10
> + * MT9P031 seems to be close enough, so use constants from that datasheet for
> + * now.
> + * But keep the name MT9P031 to remind us, that this isn't really confirmed
> + * for this sensor.
> + */
> +#define MT9P031_PLL_CONTROL				0x10
> +#define		MT9P031_PLL_CONTROL_PWROFF		0x0050
> +#define		MT9P031_PLL_CONTROL_PWRON		0x0051
> +#define		MT9P031_PLL_CONTROL_USEPLL		0x0052
> +#define MT9P031_PLL_CONFIG2				0x11
> +#define		MT9P031_PLL_CONFIG2_P1_DIV_MASK		0x1f
> +
> +struct mt9m032 {
> +	struct v4l2_subdev subdev;
> +	struct media_pad pad;
> +	struct mt9m032_platform_data *pdata;
> +
> +	struct v4l2_ctrl_handler ctrls;
> +	struct {
> +		struct v4l2_ctrl *hflip;
> +		struct v4l2_ctrl *vflip;
> +	};
> +
> +	bool streaming;
> +
> +	unsigned int pix_clock;
> +
> +	struct v4l2_mbus_framefmt format;
> +	struct v4l2_rect crop;
> +	struct v4l2_fract frame_interval;
> +};
> +
> +#define to_mt9m032(sd)	container_of(sd, struct mt9m032, subdev)
> +#define to_dev(sensor) \
> +	(&((struct i2c_client *)v4l2_get_subdevdata(&(sensor)->subdev))->dev)
> +
> +static int mt9m032_read(struct i2c_client *client, u8 reg)
> +{
> +	return i2c_smbus_read_word_swapped(client, reg);
> +}
> +
> +static int mt9m032_write(struct i2c_client *client, u8 reg, const u16 data)
> +{
> +	return i2c_smbus_write_word_swapped(client, reg, data);
> +}
> +
> +static u32 mt9m032_row_time(struct mt9m032 *sensor, unsigned int width)
> +{
> +	unsigned int effective_width;
> +	u32 ns;
> +
> +	effective_width = width + 716; /* emperical value */

Why empirical value? This should be directly related to image width
(before binning) and horizontal blanking.

> +	ns = div_u64(1000000000ULL * effective_width, sensor->pix_clock);
> +	dev_dbg(to_dev(sensor),	"MT9M032 line time: %u ns\n", ns);
> +	return ns;
> +}
> +
> +static int mt9m032_update_timing(struct mt9m032 *sensor,
> +				 struct v4l2_fract *interval)
> +{
> +	struct i2c_client *client = v4l2_get_subdevdata(&sensor->subdev);
> +	struct v4l2_rect *crop = &sensor->crop;
> +	unsigned int min_vblank;
> +	unsigned int vblank;
> +	u32 row_time;
> +
> +	if (!interval)
> +		interval = &sensor->frame_interval;
> +
> +	row_time = mt9m032_row_time(sensor, crop->width);
> +
> +	vblank = div_u64(1000000000ULL * interval->numerator,
> +			 (u64)row_time * interval->denominator)
> +	       - crop->height;
> +
> +	if (vblank > MT9M032_VBLANK_MAX) {
> +		/* hardware limits to 11 bit values */
> +		interval->denominator = 1000;
> +		interval->numerator =
> +			div_u64((crop->height + MT9M032_VBLANK_MAX) *
> +				(u64)row_time * interval->denominator,
> +				1000000000ULL);
> +		vblank = div_u64(1000000000ULL * interval->numerator,
> +				 (u64)row_time * interval->denominator)
> +		       - crop->height;
> +	}
> +	/* enforce minimal 1.6ms blanking time. */
> +	min_vblank = 1600000 / row_time;
> +	vblank = clamp_t(unsigned int, vblank, min_vblank, MT9M032_VBLANK_MAX);
> +
> +	return mt9m032_write(client, MT9M032_VBLANK, vblank);
> +}
> +
> +static int mt9m032_update_geom_timing(struct mt9m032 *sensor)
> +{
> +	struct i2c_client *client = v4l2_get_subdevdata(&sensor->subdev);
> +	int ret;
> +
> +	ret = mt9m032_write(client, MT9M032_COLUMN_SIZE,
> +			    sensor->crop.width - 1);
> +	if (!ret)
> +		ret = mt9m032_write(client, MT9M032_ROW_SIZE,
> +				    sensor->crop.height - 1);
> +	if (!ret)
> +		ret = mt9m032_write(client, MT9M032_COLUMN_START,
> +				    sensor->crop.left);
> +	if (!ret)
> +		ret = mt9m032_write(client, MT9M032_ROW_START,
> +				    sensor->crop.top);
> +	if (!ret)
> +		ret = mt9m032_update_timing(sensor, NULL);
> +	return ret;
> +}
> +
> +static int update_formatter2(struct mt9m032 *sensor, bool streaming)
> +{
> +	struct i2c_client *client = v4l2_get_subdevdata(&sensor->subdev);
> +	u16 reg_val =   MT9M032_FORMATTER2_DOUT_EN
> +		      | 0x0070;  /* parts reserved! */
> +				 /* possibly for changing to 14-bit mode */
> +
> +	if (streaming)
> +		reg_val |= MT9M032_FORMATTER2_PIXCLK_EN;   /* pixclock enable */
> +
> +	return mt9m032_write(client, MT9M032_FORMATTER2, reg_val);
> +}
> +
> +static int mt9m032_setup_pll(struct mt9m032 *sensor)
> +{
> +	static const struct aptina_pll_limits limits = {
> +		.ext_clock_min = 8000000,
> +		.ext_clock_max = 16500000,
> +		.int_clock_min = 2000000,
> +		.int_clock_max = 24000000,
> +		.out_clock_min = 322000000,
> +		.out_clock_max = 693000000,
> +		.pix_clock_max = 99000000,
> +		.n_min = 1,
> +		.n_max = 64,
> +		.m_min = 16,
> +		.m_max = 255,
> +		.p1_min = 1,
> +		.p1_max = 128,
> +	};
> +
> +	struct i2c_client *client = v4l2_get_subdevdata(&sensor->subdev);
> +	struct mt9m032_platform_data *pdata = sensor->pdata;
> +	struct aptina_pll pll;
> +	int ret;
> +
> +	pll.ext_clock = pdata->ext_clock;
> +	pll.pix_clock = pdata->pix_clock;

You could initialise these in the declaration.

> +	ret = aptina_pll_calculate(&client->dev, &limits, &pll);
> +	if (ret < 0)
> +		return ret;
> +
> +	sensor->pix_clock = pll.pix_clock;
> +
> +	ret = mt9m032_write(client, MT9M032_PLL_CONFIG1,
> +			    (pll.m << MT9M032_PLL_CONFIG1_MUL_SHIFT)
> +			    | (pll.p1 - 1));
> +	if (!ret)
> +		ret = mt9m032_write(client, MT9P031_PLL_CONFIG2, pll.n - 1);
> +	if (!ret)
> +		ret = mt9m032_write(client, MT9P031_PLL_CONTROL,
> +				    MT9P031_PLL_CONTROL_PWRON |
> +				    MT9P031_PLL_CONTROL_USEPLL);
> +	if (!ret)		/* more reserved, Continuous, Master Mode */
> +		ret = mt9m032_write(client, MT9M032_READ_MODE1, 0x8006);
> +	if (!ret)		/* Set 14-bit mode, select 7 divider */
> +		ret = mt9m032_write(client, MT9M032_FORMATTER1, 0x111e);

I hope the datasheet is public. :-)

If there is one in a known URL it wouldn't hurt to refer to it, I think.

> +	return ret;
> +}
> +
> +/* -----------------------------------------------------------------------------
> + * Subdev pad operations
> + */
> +
> +static int mt9m032_enum_mbus_code(struct v4l2_subdev *subdev,
> +				  struct v4l2_subdev_fh *fh,
> +				  struct v4l2_subdev_mbus_code_enum *code)
> +{
> +	if (code->index != 0)
> +		return -EINVAL;
> +
> +	code->code = V4L2_MBUS_FMT_Y8_1X8;
> +	return 0;
> +}
> +
> +static int mt9m032_enum_frame_size(struct v4l2_subdev *subdev,
> +				   struct v4l2_subdev_fh *fh,
> +				   struct v4l2_subdev_frame_size_enum *fse)
> +{
> +	if (fse->index != 0 || fse->code != V4L2_MBUS_FMT_Y8_1X8)
> +		return -EINVAL;
> +
> +	fse->min_width = MT9M032_COLUMN_SIZE_DEF;
> +	fse->max_width = MT9M032_COLUMN_SIZE_DEF;
> +	fse->min_height = MT9M032_ROW_SIZE_DEF;
> +	fse->max_height = MT9M032_ROW_SIZE_DEF;
> +
> +	return 0;
> +}
> +
> +/**
> + * __mt9m032_get_pad_crop() - get crop rect
> + * @sensor: pointer to the sensor struct
> + * @fh: filehandle for getting the try crop rect from
> + * @which: select try or active crop rect
> + *
> + * Returns a pointer the current active or fh relative try crop rect
> + */
> +static struct v4l2_rect *
> +__mt9m032_get_pad_crop(struct mt9m032 *sensor, struct v4l2_subdev_fh *fh,
> +		       enum v4l2_subdev_format_whence which)
> +{
> +	switch (which) {
> +	case V4L2_SUBDEV_FORMAT_TRY:
> +		return v4l2_subdev_get_try_crop(fh, 0);
> +	case V4L2_SUBDEV_FORMAT_ACTIVE:
> +		return &sensor->crop;
> +	default:
> +		return NULL;

BUG()? Just a thought.

> +	}
> +}
> +
> +/**
> + * __mt9m032_get_pad_format() - get format
> + * @sensor: pointer to the sensor struct
> + * @fh: filehandle for getting the try format from
> + * @which: select try or active format
> + *
> + * Returns a pointer the current active or fh relative try format
> + */
> +static struct v4l2_mbus_framefmt *
> +__mt9m032_get_pad_format(struct mt9m032 *sensor, struct v4l2_subdev_fh *fh,
> +			 enum v4l2_subdev_format_whence which)
> +{
> +	switch (which) {
> +	case V4L2_SUBDEV_FORMAT_TRY:
> +		return v4l2_subdev_get_try_format(fh, 0);
> +	case V4L2_SUBDEV_FORMAT_ACTIVE:
> +		return &sensor->format;
> +	default:
> +		return NULL;

Here as well?

> +	}
> +}
> +
> +static int mt9m032_get_pad_format(struct v4l2_subdev *subdev,
> +				  struct v4l2_subdev_fh *fh,
> +				  struct v4l2_subdev_format *fmt)
> +{
> +	struct mt9m032 *sensor = to_mt9m032(subdev);
> +
> +	fmt->format = *__mt9m032_get_pad_format(sensor, fh, fmt->which);
> +	return 0;
> +}
> +
> +static int mt9m032_set_pad_format(struct v4l2_subdev *subdev,
> +				  struct v4l2_subdev_fh *fh,
> +				  struct v4l2_subdev_format *fmt)
> +{
> +	struct mt9m032 *sensor = to_mt9m032(subdev);
> +
> +	if (sensor->streaming && fmt->which == V4L2_SUBDEV_FORMAT_ACTIVE)
> +		return -EBUSY;
> +
> +	/* Scaling is not supported, the format is thus fixed. */
> +	return mt9m032_get_pad_format(subdev, fh, fmt);
> +}
> +
> +static int mt9m032_get_crop(struct v4l2_subdev *subdev,
> +			    struct v4l2_subdev_fh *fh,
> +			    struct v4l2_subdev_crop *crop)
> +{
> +	struct mt9m032 *sensor = to_mt9m032(subdev);
> +
> +	crop->rect = *__mt9m032_get_pad_crop(sensor, fh, crop->which);
> +
> +	return 0;
> +}
> +
> +static int mt9m032_set_crop(struct v4l2_subdev *subdev,
> +			    struct v4l2_subdev_fh *fh,
> +			    struct v4l2_subdev_crop *crop)
> +{
> +	struct mt9m032 *sensor = to_mt9m032(subdev);
> +	struct v4l2_mbus_framefmt *format;
> +	struct v4l2_rect *__crop;
> +	struct v4l2_rect rect;
> +
> +	if (sensor->streaming && crop->which == V4L2_SUBDEV_FORMAT_ACTIVE)
> +		return -EBUSY;
> +
> +	/* Clamp the crop rectangle boundaries and align them to a multiple of 2
> +	 * pixels to ensure a GRBG Bayer pattern.
> +	 */
> +	rect.left = clamp(ALIGN(crop->rect.left, 2), MT9M032_COLUMN_START_MIN,
> +			  MT9M032_COLUMN_START_MAX);
> +	rect.top = clamp(ALIGN(crop->rect.top, 2), MT9M032_ROW_START_MIN,
> +			 MT9M032_ROW_START_MAX);
> +	rect.width = clamp(ALIGN(crop->rect.width, 2), MT9M032_COLUMN_SIZE_MIN,
> +			   MT9M032_COLUMN_SIZE_MAX);
> +	rect.height = clamp(ALIGN(crop->rect.height, 2), MT9M032_ROW_SIZE_MIN,
> +			    MT9M032_ROW_SIZE_MAX);
> +
> +	rect.width = min(rect.width, MT9M032_PIXEL_ARRAY_WIDTH - rect.left);
> +	rect.height = min(rect.height, MT9M032_PIXEL_ARRAY_HEIGHT - rect.top);
> +
> +	__crop = __mt9m032_get_pad_crop(sensor, fh, crop->which);
> +
> +	if (rect.width != __crop->width || rect.height != __crop->height) {
> +		/* Reset the output image size if the crop rectangle size has
> +		 * been modified.
> +		 */
> +		format = __mt9m032_get_pad_format(sensor, fh, crop->which);
> +		format->width = rect.width;
> +		format->height = rect.height;

I think you can do this unconditionally.

> +	}
> +
> +	*__crop = rect;
> +	crop->rect = rect;
> +
> +	if (crop->which != V4L2_SUBDEV_FORMAT_ACTIVE)
> +		return 0;
> +
> +	return mt9m032_update_geom_timing(sensor);
> +}
> +
> +static int mt9m032_get_frame_interval(struct v4l2_subdev *subdev,
> +				      struct v4l2_subdev_frame_interval *fi)
> +{
> +	struct mt9m032 *sensor = to_mt9m032(subdev);
> +
> +	memset(fi, 0, sizeof(*fi));
> +	fi->interval = sensor->frame_interval;
> +
> +	return 0;
> +}
> +
v> +static int mt9m032_set_frame_interval(struct v4l2_subdev *subdev,
> +				      struct v4l2_subdev_frame_interval *fi)
> +{
> +	struct mt9m032 *sensor = to_mt9m032(subdev);
> +	int ret;
> +
> +	if (sensor->streaming)
> +		return -EBUSY;
> +
> +	memset(fi->reserved, 0, sizeof(fi->reserved));

I'm not quite sure these should be touched.

> +	ret = mt9m032_update_timing(sensor, &fi->interval);
> +	if (!ret)
> +		sensor->frame_interval = fi->interval;
> +
> +	return ret;
> +}
> +
> +static int mt9m032_s_stream(struct v4l2_subdev *subdev, int streaming)
> +{
> +	struct mt9m032 *sensor = to_mt9m032(subdev);
> +	int ret;
> +
> +	ret = update_formatter2(sensor, streaming);
> +	if (!ret)
> +		sensor->streaming = streaming;
> +	return ret;
> +}
> +
> +/* -----------------------------------------------------------------------------
> + * V4L2 subdev core operations
> + */
> +
> +#ifdef CONFIG_VIDEO_ADV_DEBUG
> +static int mt9m032_g_register(struct v4l2_subdev *sd,
> +			      struct v4l2_dbg_register *reg)
> +{
> +	struct mt9m032 *sensor = to_mt9m032(sd);
> +	struct i2c_client *client = v4l2_get_subdevdata(&sensor->subdev);
> +	int val;
> +
> +	if (reg->match.type != V4L2_CHIP_MATCH_I2C_ADDR || reg->reg > 0xff)
> +		return -EINVAL;
> +	if (reg->match.addr != client->addr)
> +		return -ENODEV;
> +
> +	val = mt9m032_read(client, reg->reg);
> +	if (val < 0)
> +		return -EIO;
> +
> +	reg->size = 2;
> +	reg->val = val;
> +
> +	return 0;
> +}
> +
> +static int mt9m032_s_register(struct v4l2_subdev *sd,
> +			      struct v4l2_dbg_register *reg)
> +{
> +	struct mt9m032 *sensor = to_mt9m032(sd);
> +	struct i2c_client *client = v4l2_get_subdevdata(&sensor->subdev);
> +
> +	if (reg->match.type != V4L2_CHIP_MATCH_I2C_ADDR || reg->reg > 0xff)
> +		return -EINVAL;
> +
> +	if (reg->match.addr != client->addr)
> +		return -ENODEV;
> +
> +	return mt9m032_write(client, reg->reg, reg->val);
> +}
> +#endif
> +
> +/* -----------------------------------------------------------------------------
> + * V4L2 subdev control operations
> + */
> +
> +static int update_read_mode2(struct mt9m032 *sensor, bool vflip, bool hflip)
> +{
> +	struct i2c_client *client = v4l2_get_subdevdata(&sensor->subdev);
> +	int reg_val = (!!vflip) << MT9M032_READ_MODE2_VFLIP_SHIFT
> +		    | (!!hflip) << MT9M032_READ_MODE2_HFLIP_SHIFT
> +		    | MT9M032_READ_MODE2_ROW_BLC
> +		    | 0x0007;
> +
> +	return mt9m032_write(client, MT9M032_READ_MODE2, reg_val);
> +}
> +
> +static int mt9m032_set_gain(struct mt9m032 *sensor, s32 val)
> +{
> +	struct i2c_client *client = v4l2_get_subdevdata(&sensor->subdev);
> +	int digital_gain_val;	/* in 1/8th (0..127) */
> +	int analog_mul;		/* 0 or 1 */
> +	int analog_gain_val;	/* in 1/16th. (0..63) */
> +	u16 reg_val;
> +
> +	digital_gain_val = 51; /* from setup example */
> +
> +	if (val < 63) {
> +		analog_mul = 0;
> +		analog_gain_val = val;
> +	} else {
> +		analog_mul = 1;
> +		analog_gain_val = val / 2;
> +	}
> +
> +	/* a_gain = (1+analog_mul) + (analog_gain_val+1)/16 */
> +	/* overall_gain = a_gain * (1 + digital_gain_val / 8) */
> +
> +	reg_val = ((digital_gain_val & MT9M032_GAIN_DIGITAL_MASK)
> +		   << MT9M032_GAIN_DIGITAL_SHIFT)
> +		| ((analog_mul & 1) << MT9M032_GAIN_AMUL_SHIFT)
> +		| (analog_gain_val & MT9M032_GAIN_ANALOG_MASK);
> +
> +	return mt9m032_write(client, MT9M032_GAIN_ALL, reg_val);
> +}
> +
> +static int mt9m032_try_ctrl(struct v4l2_ctrl *ctrl)
> +{
> +	if (ctrl->id == V4L2_CID_GAIN && ctrl->val >= 63) {
> +		/* round because of multiplier used for values >= 63 */
> +		ctrl->val &= ~1;
> +	}
> +
> +	return 0;
> +}
> +
> +static int mt9m032_set_ctrl(struct v4l2_ctrl *ctrl)
> +{
> +	struct mt9m032 *sensor =
> +		container_of(ctrl->handler, struct mt9m032, ctrls);
> +	struct i2c_client *client = v4l2_get_subdevdata(&sensor->subdev);
> +	int ret;
> +
> +	switch (ctrl->id) {
> +	case V4L2_CID_GAIN:
> +		return mt9m032_set_gain(sensor, ctrl->val);

The gain control only touches analogue gain. Shouldn't you use
V4L2_CID_ANALOGUE_GAIN (or something alike) instead?

> +	case V4L2_CID_HFLIP:
> +	case V4L2_CID_VFLIP:
> +		return update_read_mode2(sensor, sensor->vflip->val,
> +					 sensor->hflip->val);
> +
> +	case V4L2_CID_EXPOSURE:
> +		ret = mt9m032_write(client, MT9M032_SHUTTER_WIDTH_HIGH,
> +				    (ctrl->val >> 16) & 0xffff);
> +		if (ret < 0)
> +			return ret;
> +
> +		return mt9m032_write(client, MT9M032_SHUTTER_WIDTH_LOW,
> +				     ctrl->val & 0xffff);
> +
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static struct v4l2_ctrl_ops mt9m032_ctrl_ops = {
> +	.s_ctrl = mt9m032_set_ctrl,
> +	.try_ctrl = mt9m032_try_ctrl,
> +};
> +
> +/* -------------------------------------------------------------------------- */
> +
> +static const struct v4l2_subdev_core_ops mt9m032_core_ops = {
> +#ifdef CONFIG_VIDEO_ADV_DEBUG
> +	.g_register = mt9m032_g_register,
> +	.s_register = mt9m032_s_register,
> +#endif
> +};
> +
> +static const struct v4l2_subdev_video_ops mt9m032_video_ops = {
> +	.s_stream = mt9m032_s_stream,
> +	.g_frame_interval = mt9m032_get_frame_interval,
> +	.s_frame_interval = mt9m032_set_frame_interval,
> +};
> +
> +static const struct v4l2_subdev_pad_ops mt9m032_pad_ops = {
> +	.enum_mbus_code = mt9m032_enum_mbus_code,
> +	.enum_frame_size = mt9m032_enum_frame_size,
> +	.get_fmt = mt9m032_get_pad_format,
> +	.set_fmt = mt9m032_set_pad_format,
> +	.set_crop = mt9m032_set_crop,
> +	.get_crop = mt9m032_get_crop,
> +};
> +
> +static const struct v4l2_subdev_ops mt9m032_ops = {
> +	.core = &mt9m032_core_ops,
> +	.video = &mt9m032_video_ops,
> +	.pad = &mt9m032_pad_ops,
> +};
> +
> +/* -----------------------------------------------------------------------------
> + * Driver initialization and probing
> + */
> +
> +static int mt9m032_probe(struct i2c_client *client,
> +			 const struct i2c_device_id *devid)
> +{
> +	struct i2c_adapter *adapter = client->adapter;
> +	struct mt9m032 *sensor;
> +	int chip_version;
> +	int ret;
> +
> +	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA)) {
> +		dev_warn(&client->dev,
> +			 "I2C-Adapter doesn't support I2C_FUNC_SMBUS_WORD\n");
> +		return -EIO;
> +	}
> +
> +	if (!client->dev.platform_data)
> +		return -ENODEV;
> +
> +	sensor = kzalloc(sizeof(*sensor), GFP_KERNEL);
> +	if (sensor == NULL)
> +		return -ENOMEM;
> +
> +	sensor->pdata = client->dev.platform_data;
> +
> +	v4l2_i2c_subdev_init(&sensor->subdev, client, &mt9m032_ops);
> +	sensor->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> +
> +	chip_version = mt9m032_read(client, MT9M032_CHIP_VERSION);
> +	if (chip_version != MT9M032_CHIP_VERSION_VALUE) {
> +		dev_err(&client->dev, "MT9M032 not detected, wrong version "
> +			"0x%04x\n", chip_version);
> +		ret = -ENODEV;
> +		goto free_sensor;
> +	}
> +
> +	dev_info(&client->dev, "MT9P031 detected at address 0x%02x\n",
> +		 client->addr);
> +
> +	sensor->frame_interval.numerator = 1;
> +	sensor->frame_interval.denominator = 30;
> +
> +	sensor->crop.left = 416;
> +	sensor->crop.top = 360;
> +	sensor->crop.width = 640;
> +	sensor->crop.height = 480;
> +
> +	sensor->format.width = sensor->crop.width;
> +	sensor->format.height = sensor->crop.height;
> +	sensor->format.code = V4L2_MBUS_FMT_Y8_1X8;
> +	sensor->format.field = V4L2_FIELD_NONE;
> +	sensor->format.colorspace = V4L2_COLORSPACE_SRGB;
> +
> +	v4l2_ctrl_handler_init(&sensor->ctrls, 4);
> +
> +	v4l2_ctrl_new_std(&sensor->ctrls, &mt9m032_ctrl_ops,
> +			  V4L2_CID_GAIN, 0, 127, 1, 64);
> +
> +	sensor->hflip = v4l2_ctrl_new_std(&sensor->ctrls,
> +					  &mt9m032_ctrl_ops,
> +					  V4L2_CID_HFLIP, 0, 1, 1, 0);
> +	sensor->vflip = v4l2_ctrl_new_std(&sensor->ctrls,
> +					  &mt9m032_ctrl_ops,
> +					  V4L2_CID_VFLIP, 0, 1, 1, 0);
> +
> +	v4l2_ctrl_new_std(&sensor->ctrls, &mt9m032_ctrl_ops,
> +			  V4L2_CID_EXPOSURE, MT9M032_SHUTTER_WIDTH_MIN,
> +			  MT9M032_SHUTTER_WIDTH_MAX, 1,
> +			  MT9M032_SHUTTER_WIDTH_DEF);
> +
> +	if (sensor->ctrls.error) {
> +		ret = sensor->ctrls.error;
> +		dev_err(&client->dev, "control initialization error %d\n", ret);
> +		goto free_ctrl;
> +	}
> +
> +	v4l2_ctrl_cluster(2, &sensor->hflip);
> +
> +	sensor->subdev.ctrl_handler = &sensor->ctrls;
> +	sensor->pad.flags = MEDIA_PAD_FL_SOURCE;
> +	ret = media_entity_init(&sensor->subdev.entity, 1, &sensor->pad, 0);
> +	if (ret < 0)
> +		goto free_ctrl;
> +
> +	ret = mt9m032_write(client, MT9M032_RESET, 1);	/* reset on */
> +	if (ret < 0)
> +		goto free_ctrl;
> +	mt9m032_write(client, MT9M032_RESET, 0);	/* reset off */
> +	if (ret < 0)
> +		goto free_ctrl;
> +
> +	ret = mt9m032_setup_pll(sensor);
> +	if (ret < 0)
> +		goto free_ctrl;
> +	usleep_range(10000, 11000);
> +
> +	v4l2_ctrl_handler_setup(&sensor->ctrls);
> +
> +	/* SIZE */
> +	ret = mt9m032_update_geom_timing(sensor);
> +	if (ret < 0)
> +		goto free_ctrl;
> +
> +	ret = mt9m032_write(client, 0x41, 0x0000);	/* reserved !!! */
> +	if (ret < 0)
> +		goto free_ctrl;
> +	ret = mt9m032_write(client, 0x42, 0x0003);	/* reserved !!! */
> +	if (ret < 0)
> +		goto free_ctrl;
> +	ret = mt9m032_write(client, 0x43, 0x0003);	/* reserved !!! */
> +	if (ret < 0)
> +		goto free_ctrl;
> +	ret = mt9m032_write(client, 0x7f, 0x0000);	/* reserved !!! */
> +	if (ret < 0)
> +		goto free_ctrl;
> +	if (sensor->pdata->invert_pixclock) {
> +		ret = mt9m032_write(client, MT9M032_PIX_CLK_CTRL,
> +				    MT9M032_PIX_CLK_CTRL_INV_PIXCLK);
> +		if (ret < 0)
> +			goto free_ctrl;
> +	}
> +
> +	ret = mt9m032_write(client, MT9M032_RESTART, 1); /* Restart on */
> +	if (ret < 0)
> +		goto free_ctrl;
> +	msleep(100);
> +	ret = mt9m032_write(client, MT9M032_RESTART, 0); /* Restart off */
> +	if (ret < 0)
> +		goto free_ctrl;
> +	msleep(100);
> +	ret = update_formatter2(sensor, false);
> +	if (ret < 0)
> +		goto free_ctrl;
> +
> +	return ret;
> +
> +free_ctrl:
> +	v4l2_ctrl_handler_free(&sensor->ctrls);
> +
> +free_sensor:
> +	kfree(sensor);
> +	return ret;
> +}
> +
> +static int mt9m032_remove(struct i2c_client *client)
> +{
> +	struct v4l2_subdev *subdev = i2c_get_clientdata(client);
> +	struct mt9m032 *sensor = to_mt9m032(subdev);
> +
> +	v4l2_device_unregister_subdev(&sensor->subdev);
> +	v4l2_ctrl_handler_free(&sensor->ctrls);
> +	media_entity_cleanup(&sensor->subdev.entity);
> +	kfree(sensor);
> +	return 0;
> +}
> +
> +static const struct i2c_device_id mt9m032_id_table[] = {
> +	{ MT9M032_NAME, 0 },
> +	{ }
> +};
> +
> +MODULE_DEVICE_TABLE(i2c, mt9m032_id_table);
> +
> +static struct i2c_driver mt9m032_i2c_driver = {
> +	.driver = {
> +		.name = MT9M032_NAME,
> +	},
> +	.probe = mt9m032_probe,
> +	.remove = mt9m032_remove,
> +	.id_table = mt9m032_id_table,
> +};
> +
> +module_i2c_driver(mt9m032_i2c_driver);
> +
> +MODULE_AUTHOR("Martin Hostettler <martin@neutronstar.dyndns.org>");
> +MODULE_DESCRIPTION("MT9M032 camera sensor driver");
> +MODULE_LICENSE("GPL v2");
> diff --git a/include/media/mt9m032.h b/include/media/mt9m032.h
> new file mode 100644
> index 0000000..c3a7811
> --- /dev/null
> +++ b/include/media/mt9m032.h
> @@ -0,0 +1,36 @@
> +/*
> + * Driver for MT9M032 CMOS Image Sensor from Micron
> + *
> + * Copyright (C) 2010-2011 Lund Engineering
> + * Contact: Gil Lund <gwlund@lundeng.com>
> + * Author: Martin Hostettler <martin@neutronstar.dyndns.org>
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License
> + * version 2 as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful, but
> + * WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
> + * 02110-1301 USA
> + *
> + */
> +
> +#ifndef MT9M032_H
> +#define MT9M032_H
> +
> +#define MT9M032_NAME		"mt9m032"
> +#define MT9M032_I2C_ADDR	(0xb8 >> 1)
> +
> +struct mt9m032_platform_data {
> +	u32 ext_clock;
> +	u32 pix_clock;
> +	bool invert_pixclock;
> +
> +};
> +#endif /* MT9M032_H */

Regards,

-- 
Sakari Ailus
sakari.ailus@iki.fi

Re: [PATCH v3 5/5] v4l: Add driver for Micron MT9M032 camera sensor

[Laurent Pinchart]

Hi Sakari,

On Wednesday 07 March 2012 01:16:33 Sakari Ailus wrote:
> Hi Laurent,
> 
> Thanks for the patch.
> 
> I have a few comments below. Just one fairly general question: locking.
> Shouldn't you serialise accesses to sensor registers and your data,
> possibly by using a mutex?

I guess I should, yes... :-) will fix.

> Laurent Pinchart wrote:
> > From: Martin Hostettler <martin@neutronstar.dyndns.org>
> > 
> > The MT9M032 is a parallel 1.6MP sensor from Micron controlled through I2C.
> > 
> > The driver creates a V4L2 subdevice. It currently supports cropping, gain,
> > exposure and v/h flipping controls in monochrome mode with an
> > external pixel clock.
> > 
> > Signed-off-by: Martin Hostettler <martin@neutronstar.dyndns.org>
> > [Lots of clean up, fixes and enhancements]
> > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

[snip]

> > diff --git a/drivers/media/video/Makefile b/drivers/media/video/Makefile
> > index d1304e1..8e037e9 100644
> > --- a/drivers/media/video/Makefile
> > +++ b/drivers/media/video/Makefile
> > @@ -82,6 +82,7 @@ obj-$(CONFIG_VIDEO_AS3645A)	+= as3645a.o
> > 
> >  obj-$(CONFIG_SOC_CAMERA_IMX074)		+= imx074.o
> >  obj-$(CONFIG_SOC_CAMERA_MT9M001)	+= mt9m001.o
> > 
> > +obj-$(CONFIG_VIDEO_MT9M032)             += mt9m032.o
> 
> I would put this among the other subdev sensor drivers instead.

Good point.

> >  obj-$(CONFIG_SOC_CAMERA_MT9M111)	+= mt9m111.o
> >  obj-$(CONFIG_SOC_CAMERA_MT9T031)	+= mt9t031.o
> >  obj-$(CONFIG_SOC_CAMERA_MT9T112)	+= mt9t112.o
> > 
> > diff --git a/drivers/media/video/mt9m032.c b/drivers/media/video/mt9m032.c
> > new file mode 100644
> > index 0000000..c3d69aa
> > --- /dev/null
> > +++ b/drivers/media/video/mt9m032.c

[snip]

> > +static u32 mt9m032_row_time(struct mt9m032 *sensor, unsigned int width)
> > +{
> > +	unsigned int effective_width;
> > +	u32 ns;
> > +
> > +	effective_width = width + 716; /* emperical value */
> 
> Why empirical value? This should be directly related to image width
> (before binning) and horizontal blanking.

Ask Martin :-)

I don't have access to the documentation nor the hardware, so I'd rather keep 
the value as-is for now.

> > +	ns = div_u64(1000000000ULL * effective_width, sensor->pix_clock);
> > +	dev_dbg(to_dev(sensor),	"MT9M032 line time: %u ns\n", ns);
> > +	return ns;
> > +}

[snip]

> > +static int mt9m032_setup_pll(struct mt9m032 *sensor)
> > +{
> > +	static const struct aptina_pll_limits limits = {
> > +		.ext_clock_min = 8000000,
> > +		.ext_clock_max = 16500000,
> > +		.int_clock_min = 2000000,
> > +		.int_clock_max = 24000000,
> > +		.out_clock_min = 322000000,
> > +		.out_clock_max = 693000000,
> > +		.pix_clock_max = 99000000,
> > +		.n_min = 1,
> > +		.n_max = 64,
> > +		.m_min = 16,
> > +		.m_max = 255,
> > +		.p1_min = 1,
> > +		.p1_max = 128,
> > +	};
> > +
> > +	struct i2c_client *client = v4l2_get_subdevdata(&sensor->subdev);
> > +	struct mt9m032_platform_data *pdata = sensor->pdata;
> > +	struct aptina_pll pll;
> > +	int ret;
> > +
> > +	pll.ext_clock = pdata->ext_clock;
> > +	pll.pix_clock = pdata->pix_clock;
> 
> You could initialise these in the declaration.

Yes, but I would find that less readable :-)

> > +	ret = aptina_pll_calculate(&client->dev, &limits, &pll);
> > +	if (ret < 0)
> > +		return ret;
> > +
> > +	sensor->pix_clock = pll.pix_clock;
> > +
> > +	ret = mt9m032_write(client, MT9M032_PLL_CONFIG1,
> > +			    (pll.m << MT9M032_PLL_CONFIG1_MUL_SHIFT)
> > +			    | (pll.p1 - 1));
> > +	if (!ret)
> > +		ret = mt9m032_write(client, MT9P031_PLL_CONFIG2, pll.n - 1);
> > +	if (!ret)
> > +		ret = mt9m032_write(client, MT9P031_PLL_CONTROL,
> > +				    MT9P031_PLL_CONTROL_PWRON |
> > +				    MT9P031_PLL_CONTROL_USEPLL);
> > +	if (!ret)		/* more reserved, Continuous, Master Mode */
> > +		ret = mt9m032_write(client, MT9M032_READ_MODE1, 0x8006);
> > +	if (!ret)		/* Set 14-bit mode, select 7 divider */
> > +		ret = mt9m032_write(client, MT9M032_FORMATTER1, 0x111e);
> 
> I hope the datasheet is public. :-)
> 
> If there is one in a known URL it wouldn't hurt to refer to it, I think.

It's not public, and I don't have access to it (yet at least). I would have 
modified this otherwise.

> > +	return ret;
> > +}

[snip]

> > +/**
> > + * __mt9m032_get_pad_crop() - get crop rect
> > + * @sensor: pointer to the sensor struct
> > + * @fh: filehandle for getting the try crop rect from
> > + * @which: select try or active crop rect
> > + *
> > + * Returns a pointer the current active or fh relative try crop rect
> > + */
> > +static struct v4l2_rect *
> > +__mt9m032_get_pad_crop(struct mt9m032 *sensor, struct v4l2_subdev_fh *fh,
> > +		       enum v4l2_subdev_format_whence which)
> > +{
> > +	switch (which) {
> > +	case V4L2_SUBDEV_FORMAT_TRY:
> > +		return v4l2_subdev_get_try_crop(fh, 0);
> > +	case V4L2_SUBDEV_FORMAT_ACTIVE:
> > +		return &sensor->crop;
> > +	default:
> > +		return NULL;
> 
> BUG()? Just a thought.

BUG() will result in a panic(), while NULL here will "just" trigger an oops 
(so the bug will be caught) and won't render the system unusable.

> > +	}
> > +}
> > +
> > +/**
> > + * __mt9m032_get_pad_format() - get format
> > + * @sensor: pointer to the sensor struct
> > + * @fh: filehandle for getting the try format from
> > + * @which: select try or active format
> > + *
> > + * Returns a pointer the current active or fh relative try format
> > + */
> > +static struct v4l2_mbus_framefmt *
> > +__mt9m032_get_pad_format(struct mt9m032 *sensor, struct v4l2_subdev_fh
> > *fh, +			 enum v4l2_subdev_format_whence which)
> > +{
> > +	switch (which) {
> > +	case V4L2_SUBDEV_FORMAT_TRY:
> > +		return v4l2_subdev_get_try_format(fh, 0);
> > +	case V4L2_SUBDEV_FORMAT_ACTIVE:
> > +		return &sensor->format;
> > +	default:
> > +		return NULL;
> 
> Here as well?
> 
> > +	}
> > +}

[snip]

> > +static int mt9m032_set_crop(struct v4l2_subdev *subdev,
> > +			    struct v4l2_subdev_fh *fh,
> > +			    struct v4l2_subdev_crop *crop)
> > +{
> > +	struct mt9m032 *sensor = to_mt9m032(subdev);
> > +	struct v4l2_mbus_framefmt *format;
> > +	struct v4l2_rect *__crop;
> > +	struct v4l2_rect rect;
> > +
> > +	if (sensor->streaming && crop->which == V4L2_SUBDEV_FORMAT_ACTIVE)
> > +		return -EBUSY;
> > +
> > +	/* Clamp the crop rectangle boundaries and align them to a multiple 
of 2
> > +	 * pixels to ensure a GRBG Bayer pattern.
> > +	 */
> > +	rect.left = clamp(ALIGN(crop->rect.left, 2), 
MT9M032_COLUMN_START_MIN,
> > +			  MT9M032_COLUMN_START_MAX);
> > +	rect.top = clamp(ALIGN(crop->rect.top, 2), MT9M032_ROW_START_MIN,
> > +			 MT9M032_ROW_START_MAX);
> > +	rect.width = clamp(ALIGN(crop->rect.width, 2), 
MT9M032_COLUMN_SIZE_MIN,
> > +			   MT9M032_COLUMN_SIZE_MAX);
> > +	rect.height = clamp(ALIGN(crop->rect.height, 2), 
MT9M032_ROW_SIZE_MIN,
> > +			    MT9M032_ROW_SIZE_MAX);
> > +
> > +	rect.width = min(rect.width, MT9M032_PIXEL_ARRAY_WIDTH - rect.left);
> > +	rect.height = min(rect.height, MT9M032_PIXEL_ARRAY_HEIGHT - 
rect.top);
> > +
> > +	__crop = __mt9m032_get_pad_crop(sensor, fh, crop->which);
> > +
> > +	if (rect.width != __crop->width || rect.height != __crop->height) {
> > +		/* Reset the output image size if the crop rectangle size has
> > +		 * been modified.
> > +		 */
> > +		format = __mt9m032_get_pad_format(sensor, fh, crop->which);
> > +		format->width = rect.width;
> > +		format->height = rect.height;
> 
> I think you can do this unconditionally.

I could, but I hope to add binning/skipping support to this driver soon. The 
check will be needed then.
 
> > +	}
> > +
> > +	*__crop = rect;
> > +	crop->rect = rect;
> > +
> > +	if (crop->which != V4L2_SUBDEV_FORMAT_ACTIVE)
> > +		return 0;
> > +
> > +	return mt9m032_update_geom_timing(sensor);
> > +}

[snip]

> > +static int mt9m032_set_frame_interval(struct v4l2_subdev *subdev,
> > +				      struct v4l2_subdev_frame_interval *fi)
> > +{
> > +	struct mt9m032 *sensor = to_mt9m032(subdev);
> > +	int ret;
> > +
> > +	if (sensor->streaming)
> > +		return -EBUSY;
> > +
> > +	memset(fi->reserved, 0, sizeof(fi->reserved));
> 
> I'm not quite sure these should be touched.

Why not ? Do you think this could cause a regression in the future when the 
fields won't be reserved anymore ?

> > +	ret = mt9m032_update_timing(sensor, &fi->interval);
> > +	if (!ret)
> > +		sensor->frame_interval = fi->interval;
> > +
> > +	return ret;
> > +}


> > +static int mt9m032_set_ctrl(struct v4l2_ctrl *ctrl)
> > +{
> > +	struct mt9m032 *sensor =
> > +		container_of(ctrl->handler, struct mt9m032, ctrls);
> > +	struct i2c_client *client = v4l2_get_subdevdata(&sensor->subdev);
> > +	int ret;
> > +
> > +	switch (ctrl->id) {
> > +	case V4L2_CID_GAIN:
> > +		return mt9m032_set_gain(sensor, ctrl->val);
> 
> The gain control only touches analogue gain. Shouldn't you use
> V4L2_CID_ANALOGUE_GAIN (or something alike) instead?

If there was such a control in mainline, sure ;-)

I plan to revisit controls in the various Aptina sensor drivers I maintain in 
the near future. Analog/digital gains will be on my to-do list.

> > +	case V4L2_CID_HFLIP:
> > +	case V4L2_CID_VFLIP:
> > +		return update_read_mode2(sensor, sensor->vflip->val,
> > +					 sensor->hflip->val);
> > +
> > +	case V4L2_CID_EXPOSURE:
> > +		ret = mt9m032_write(client, MT9M032_SHUTTER_WIDTH_HIGH,
> > +				    (ctrl->val >> 16) & 0xffff);
> > +		if (ret < 0)
> > +			return ret;
> > +
> > +		return mt9m032_write(client, MT9M032_SHUTTER_WIDTH_LOW,
> > +				     ctrl->val & 0xffff);
> > +
> > +	default:
> > +		return -EINVAL;
> > +	}
> > +}

-- 
Regards,

Laurent Pinchart

Re: [PATCH v3 5/5] v4l: Add driver for Micron MT9M032 camera sensor

[Sakari Ailus]

Hi Laurent,

On Wed, Mar 07, 2012 at 12:31:34PM +0100, Laurent Pinchart wrote:
...
> > > +static u32 mt9m032_row_time(struct mt9m032 *sensor, unsigned int width)
> > > +{
> > > +	unsigned int effective_width;
> > > +	u32 ns;
> > > +
> > > +	effective_width = width + 716; /* emperical value */
> > 
> > Why empirical value? This should be directly related to image width
> > (before binning) and horizontal blanking.
> 
> Ask Martin :-)
> 
> I don't have access to the documentation nor the hardware, so I'd rather keep 
> the value as-is for now.

Ok. Let's keep this one then.

> > > +	ns = div_u64(1000000000ULL * effective_width, sensor->pix_clock);
> > > +	dev_dbg(to_dev(sensor),	"MT9M032 line time: %u ns\n", ns);
> > > +	return ns;
> > > +}
> 
> [snip]
> 
> > > +static int mt9m032_setup_pll(struct mt9m032 *sensor)
> > > +{
> > > +	static const struct aptina_pll_limits limits = {
> > > +		.ext_clock_min = 8000000,
> > > +		.ext_clock_max = 16500000,
> > > +		.int_clock_min = 2000000,
> > > +		.int_clock_max = 24000000,
> > > +		.out_clock_min = 322000000,
> > > +		.out_clock_max = 693000000,
> > > +		.pix_clock_max = 99000000,
> > > +		.n_min = 1,
> > > +		.n_max = 64,
> > > +		.m_min = 16,
> > > +		.m_max = 255,
> > > +		.p1_min = 1,
> > > +		.p1_max = 128,
> > > +	};
> > > +
> > > +	struct i2c_client *client = v4l2_get_subdevdata(&sensor->subdev);
> > > +	struct mt9m032_platform_data *pdata = sensor->pdata;
> > > +	struct aptina_pll pll;
> > > +	int ret;
> > > +
> > > +	pll.ext_clock = pdata->ext_clock;
> > > +	pll.pix_clock = pdata->pix_clock;
> > 
> > You could initialise these in the declaration.
> 
> Yes, but I would find that less readable :-)

Ok.

...

> > > +	rect.width = min(rect.width, MT9M032_PIXEL_ARRAY_WIDTH - rect.left);
> > > +	rect.height = min(rect.height, MT9M032_PIXEL_ARRAY_HEIGHT - 
> rect.top);
> > > +
> > > +	__crop = __mt9m032_get_pad_crop(sensor, fh, crop->which);
> > > +
> > > +	if (rect.width != __crop->width || rect.height != __crop->height) {
> > > +		/* Reset the output image size if the crop rectangle size has
> > > +		 * been modified.
> > > +		 */
> > > +		format = __mt9m032_get_pad_format(sensor, fh, crop->which);
> > > +		format->width = rect.width;
> > > +		format->height = rect.height;
> > 
> > I think you can do this unconditionally.
> 
> I could, but I hope to add binning/skipping support to this driver soon. The 
> check will be needed then.

Sounds fine for me.

> > > +	}
> > > +
> > > +	*__crop = rect;
> > > +	crop->rect = rect;
> > > +
> > > +	if (crop->which != V4L2_SUBDEV_FORMAT_ACTIVE)
> > > +		return 0;
> > > +
> > > +	return mt9m032_update_geom_timing(sensor);
> > > +}
> 
> [snip]
> 
> > > +static int mt9m032_set_frame_interval(struct v4l2_subdev *subdev,
> > > +				      struct v4l2_subdev_frame_interval *fi)
> > > +{
> > > +	struct mt9m032 *sensor = to_mt9m032(subdev);
> > > +	int ret;
> > > +
> > > +	if (sensor->streaming)
> > > +		return -EBUSY;
> > > +
> > > +	memset(fi->reserved, 0, sizeof(fi->reserved));
> > 
> > I'm not quite sure these should be touched.
> 
> Why not ? Do you think this could cause a regression in the future when the 
> fields won't be reserved anymore ?

The user is responsible for setting those fields to zero. If we set them to
zero for them they will start relying on that. At some point that might not
hold true anymore.

> > > +	ret = mt9m032_update_timing(sensor, &fi->interval);
> > > +	if (!ret)
> > > +		sensor->frame_interval = fi->interval;
> > > +
> > > +	return ret;
> > > +}
> 
> 
> > > +static int mt9m032_set_ctrl(struct v4l2_ctrl *ctrl)
> > > +{
> > > +	struct mt9m032 *sensor =
> > > +		container_of(ctrl->handler, struct mt9m032, ctrls);
> > > +	struct i2c_client *client = v4l2_get_subdevdata(&sensor->subdev);
> > > +	int ret;
> > > +
> > > +	switch (ctrl->id) {
> > > +	case V4L2_CID_GAIN:
> > > +		return mt9m032_set_gain(sensor, ctrl->val);
> > 
> > The gain control only touches analogue gain. Shouldn't you use
> > V4L2_CID_ANALOGUE_GAIN (or something alike) instead?
> 
> If there was such a control in mainline, sure ;-)
> 
> I plan to revisit controls in the various Aptina sensor drivers I maintain in 
> the near future. Analog/digital gains will be on my to-do list.

Fine for me. Let's think these after 3.4 merge window.

Cheers,

-- 
Sakari Ailus
e-mail: sakari.ailus@iki.fi	jabber/XMPP/Gmail: sailus@retiisi.org.uk

Re: [PATCH v3 5/5] v4l: Add driver for Micron MT9M032 camera sensor

[Laurent Pinchart]

Hi Sakari,

On Thursday 08 March 2012 19:17:46 Sakari Ailus wrote:
> On Wed, Mar 07, 2012 at 12:31:34PM +0100, Laurent Pinchart wrote:

[snip]

> > > > +static int mt9m032_set_frame_interval(struct v4l2_subdev *subdev,
> > > > +				      struct v4l2_subdev_frame_interval *fi)
> > > > +{
> > > > +	struct mt9m032 *sensor = to_mt9m032(subdev);
> > > > +	int ret;
> > > > +
> > > > +	if (sensor->streaming)
> > > > +		return -EBUSY;
> > > > +
> > > > +	memset(fi->reserved, 0, sizeof(fi->reserved));
> > > 
> > > I'm not quite sure these should be touched.
> > 
> > Why not ? Do you think this could cause a regression in the future when
> > the fields won't be reserved anymore ?
> 
> The user is responsible for setting those fields to zero. If we set them to
> zero for them they will start relying on that. At some point that might not
> hold true anymore.

Thinking about it some more, applications should set the reserved fields to 0, 
or first issue a get call and modify the fields it's interested in, keeping 
the reserved fields at their default value. I'll remove the memset here.

-- 
Regards,

Laurent Pinchart