[media] smiapp: Add driver

Add driver for SMIA++/SMIA image sensors. The driver exposes the sensor as
three subdevs, pixel array, binner and scaler --- in case the device has a
scaler.

Currently it relies on the board code for external clock handling. There is
no fast way out of this dependency before the ISP drivers (omap3isp) among
others will be able to export that clock through the clock framework
instead.

Signed-off-by: Sakari Ailus <sakari.ailus@maxwell.research.nokia.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 213 insertions, 0 deletions

diff --git a/drivers/media/video/smiapp/smiapp-regs.c b/drivers/media/video/smiapp/smiapp-regs.c
new file mode 100644
index 00000000000..4851ff71077
--- /dev/null
+++ b/drivers/media/video/smiapp/smiapp-regs.c
@@ -0,0 +1,213 @@
+/*
+ * drivers/media/video/smiapp/smiapp-regs.c
+ *
+ * Generic driver for SMIA/SMIA++ compliant camera modules
+ *
+ * Copyright (C) 2011--2012 Nokia Corporation
+ * Contact: Sakari Ailus <sakari.ailus@maxwell.research.nokia.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 "smiapp-debug.h"
+
+#include <linux/delay.h>
+#include <linux/i2c.h>
+
+#include "smiapp-regs.h"
+
+static uint32_t float_to_u32_mul_1000000(struct i2c_client *client,
+					 uint32_t phloat)
+{
+	int32_t exp;
+	uint64_t man;
+
+	if (phloat >= 0x80000000) {
+		dev_err(&client->dev, "this is a negative number\n");
+		return 0;
+	}
+
+	if (phloat == 0x7f800000)
+		return ~0; /* Inf. */
+
+	if ((phloat & 0x7f800000) == 0x7f800000) {
+		dev_err(&client->dev, "NaN or other special number\n");
+		return 0;
+	}
+
+	/* Valid cases begin here */
+	if (phloat == 0)
+		return 0; /* Valid zero */
+
+	if (phloat > 0x4f800000)
+		return ~0; /* larger than 4294967295 */
+
+	/*
+	 * Unbias exponent (note how phloat is now guaranteed to
+	 * have 0 in the high bit)
+	 */
+	exp = ((int32_t)phloat >> 23) - 127;
+
+	/* Extract mantissa, add missing '1' bit and it's in MHz */
+	man = ((phloat & 0x7fffff) | 0x800000) * 1000000ULL;
+
+	if (exp < 0)
+		man >>= -exp;
+	else
+		man <<= exp;
+
+	man >>= 23; /* Remove mantissa bias */
+
+	return man & 0xffffffff;
+}
+
+
+/*
+ * Read a 8/16/32-bit i2c register.  The value is returned in 'val'.
+ * Returns zero if successful, or non-zero otherwise.
+ */
+int smiapp_read(struct i2c_client *client, u32 reg, u32 *val)
+{
+	struct i2c_msg msg;
+	unsigned char data[4];
+	unsigned int len = (u8)(reg >> 16);
+	u16 offset = reg;
+	int r;
+
+	if (len != SMIA_REG_8BIT && len != SMIA_REG_16BIT
+	    && len != SMIA_REG_32BIT)
+		return -EINVAL;
+
+	msg.addr = client->addr;
+	msg.flags = 0;
+	msg.len = 2;
+	msg.buf = data;
+
+	/* high byte goes out first */
+	data[0] = (u8) (offset >> 8);
+	data[1] = (u8) offset;
+	r = i2c_transfer(client->adapter, &msg, 1);
+	if (r != 1) {
+		if (r >= 0)
+			r = -EBUSY;
+		goto err;
+	}
+
+	msg.len = len;
+	msg.flags = I2C_M_RD;
+	r = i2c_transfer(client->adapter, &msg, 1);
+	if (r != 1) {
+		if (r >= 0)
+			r = -EBUSY;
+		goto err;
+	}
+
+	*val = 0;
+	/* high byte comes first */
+	switch (len) {
+	case SMIA_REG_32BIT:
+		*val = (data[0] << 24) + (data[1] << 16) + (data[2] << 8) +
+			data[3];
+		break;
+	case SMIA_REG_16BIT:
+		*val = (data[0] << 8) + data[1];
+		break;
+	case SMIA_REG_8BIT:
+		*val = data[0];
+		break;
+	default:
+		BUG();
+	}
+
+	if (reg & SMIA_REG_FLAG_FLOAT)
+		*val = float_to_u32_mul_1000000(client, *val);
+
+	return 0;
+
+err:
+	dev_err(&client->dev, "read from offset 0x%x error %d\n", offset, r);
+
+	return r;
+}
+
+/*
+ * Write to a 8/16-bit register.
+ * Returns zero if successful, or non-zero otherwise.
+ */
+int smiapp_write(struct i2c_client *client, u32 reg, u32 val)
+{
+	struct i2c_msg msg;
+	unsigned char data[6];
+	unsigned int retries;
+	unsigned int flags = reg >> 24;
+	unsigned int len = (u8)(reg >> 16);
+	u16 offset = reg;
+	int r;
+
+	if ((len != SMIA_REG_8BIT && len != SMIA_REG_16BIT &&
+	     len != SMIA_REG_32BIT) || flags)
+		return -EINVAL;
+
+	msg.addr = client->addr;
+	msg.flags = 0; /* Write */
+	msg.len = 2 + len;
+	msg.buf = data;
+
+	/* high byte goes out first */
+	data[0] = (u8) (reg >> 8);
+	data[1] = (u8) (reg & 0xff);
+
+	switch (len) {
+	case SMIA_REG_8BIT:
+		data[2] = val;
+		break;
+	case SMIA_REG_16BIT:
+		data[2] = val >> 8;
+		data[3] = val;
+		break;
+	case SMIA_REG_32BIT:
+		data[2] = val >> 24;
+		data[3] = val >> 16;
+		data[4] = val >> 8;
+		data[5] = val;
+		break;
+	default:
+		BUG();
+	}
+
+	for (retries = 0; retries < 5; retries++) {
+		/*
+		 * Due to unknown reason sensor stops responding. This
+		 * loop is a temporaty solution until the root cause
+		 * is found.
+		 */
+		r = i2c_transfer(client->adapter, &msg, 1);
+		if (r == 1) {
+			if (retries)
+				dev_err(&client->dev,
+					"sensor i2c stall encountered. "
+					"retries: %d\n", retries);
+			return 0;
+		}
+
+		usleep_range(2000, 2000);
+	}
+
+	dev_err(&client->dev,
+		"wrote 0x%x to offset 0x%x error %d\n", val, offset, r);
+
+	return r;
+}