staging/atomisp: Add support for the Intel IPU v2

This patch adds support for the Intel IPU v2 as found on Android and IoT
Baytrail-T and Baytrail-CR platforms (those with the IPU PCI mapped). You
will also need the firmware files from your device (Android usually puts
them into /etc) - or you can find them in the downloadable restore/upgrade
kits if you blew them away for some reason.

It may be possible to extend the driver to handle the BYT/T windows
platforms such as the ASUS T100TA. These platforms don't expose the IPU via
the PCI interface but via ACPI buried in the GPU description and with the
camera information somewhere unknown so would need a platform driver
interface adding to the codebase *IFF* the firmware works on such devices.

To get good results you also need a suitable support library such as
libxcam. The camera is intended to be driven from Android so it has a lot of
features that many desktop apps don't fully spport.

In theory all the pieces are there to build it with -DISP2401 and some
differing files to get CherryTrail/T support, but unifying the drivers
properlly is a work in progress.

The IPU driver represents the work of a lot of people within Intel over many
years. It's historical goal was portability rather than Linux upstream. Any
queries about the upstream aimed driver should be sent to me not to the
original authors.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 90 insertions, 0 deletions

diff --git a/drivers/staging/media/atomisp/i2c/imx/otp_e2prom.c b/drivers/staging/media/atomisp/i2c/imx/otp_e2prom.c
new file mode 100644
index 0000000..ce4e7ab
--- /dev/null
+++ b/drivers/staging/media/atomisp/i2c/imx/otp_e2prom.c
@@ -0,0 +1,90 @@
+/*
+ * Copyright (c) 2013 Intel Corporation. All Rights Reserved.
+ *
+ * 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 Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ */
+#include <linux/bitops.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/i2c.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <media/v4l2-device.h>
+#include "common.h"
+
+/*
+ * Read EEPROM data from the gerneral e2prom chip(eg.
+ * CAT24C08, CAT24C128, le24l042cs, and store
+ * it into a kmalloced buffer. On error return NULL.
+ * @size: set to the size of the returned EEPROM data.
+ */
+void *e2prom_otp_read(struct v4l2_subdev *sd, u8 dev_addr,
+	u32 start_addr, u32 size)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(sd);
+	unsigned int e2prom_i2c_addr = dev_addr >> 1;
+	static const unsigned int max_read_size = 30;
+	int addr;
+	u32 s_addr = start_addr & E2PROM_ADDR_MASK;
+	bool two_addr = (start_addr & E2PROM_2ADDR) >> 31;
+	char *buffer;
+
+	buffer = devm_kzalloc(&client->dev, size, GFP_KERNEL);
+	if (!buffer)
+		return NULL;
+
+	for (addr = s_addr; addr < size; addr += max_read_size) {
+		struct i2c_msg msg[2];
+		unsigned int i2c_addr = e2prom_i2c_addr;
+		u16 addr_buf;
+		int r;
+
+		msg[0].flags = 0;
+		if (two_addr) {
+			msg[0].addr = i2c_addr;
+			addr_buf = cpu_to_be16(addr & 0xFFFF);
+			msg[0].len = 2;
+			msg[0].buf = (u8 *)&addr_buf;
+		} else {
+			i2c_addr |= (addr >> 8) & 0x7;
+			msg[0].addr = i2c_addr;
+			addr_buf = addr & 0xFF;
+			msg[0].len = 1;
+			msg[0].buf = (u8 *)&addr_buf;
+		}
+
+		msg[1].addr = i2c_addr;
+		msg[1].flags = I2C_M_RD;
+		msg[1].len = min(max_read_size, size - addr);
+		msg[1].buf = &buffer[addr];
+
+		r = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
+		if (r != ARRAY_SIZE(msg)) {
+			kfree(buffer);
+			dev_err(&client->dev, "read failed at 0x%03x\n", addr);
+			return NULL;
+		}
+	}
+	return buffer;
+}
+
+