File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/drivers/media/i2c/cx25840/cx25840-firmware.c b/drivers/media/i2c/cx25840/cx25840-firmware.c
new file mode 100644
index 0000000..9bbb31a
--- /dev/null
+++ b/drivers/media/i2c/cx25840/cx25840-firmware.c
@@ -0,0 +1,174 @@
+/* cx25840 firmware functions
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * 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/module.h>
+#include <linux/i2c.h>
+#include <linux/firmware.h>
+#include <media/v4l2-common.h>
+#include <media/cx25840.h>
+
+#include "cx25840-core.h"
+
+/*
+ * Mike Isely <isely@pobox.com> - The FWSEND parameter controls the
+ * size of the firmware chunks sent down the I2C bus to the chip.
+ * Previously this had been set to 1024 but unfortunately some I2C
+ * implementations can't transfer data in such big gulps.
+ * Specifically, the pvrusb2 driver has a hard limit of around 60
+ * bytes, due to the encapsulation there of I2C traffic into USB
+ * messages.  So we have to significantly reduce this parameter.
+ */
+#define FWSEND 48
+
+#define FWDEV(x) &((x)->dev)
+
+static char *firmware = "";
+
+module_param(firmware, charp, 0444);
+
+MODULE_PARM_DESC(firmware, "Firmware image to load");
+
+static void start_fw_load(struct i2c_client *client)
+{
+	/* DL_ADDR_LB=0 DL_ADDR_HB=0 */
+	cx25840_write(client, 0x800, 0x00);
+	cx25840_write(client, 0x801, 0x00);
+	// DL_MAP=3 DL_AUTO_INC=0 DL_ENABLE=1
+	cx25840_write(client, 0x803, 0x0b);
+	/* AUTO_INC_DIS=1 */
+	cx25840_write(client, 0x000, 0x20);
+}
+
+static void end_fw_load(struct i2c_client *client)
+{
+	/* AUTO_INC_DIS=0 */
+	cx25840_write(client, 0x000, 0x00);
+	/* DL_ENABLE=0 */
+	cx25840_write(client, 0x803, 0x03);
+}
+
+#define CX2388x_FIRMWARE "v4l-cx23885-avcore-01.fw"
+#define CX231xx_FIRMWARE "v4l-cx231xx-avcore-01.fw"
+#define CX25840_FIRMWARE "v4l-cx25840.fw"
+
+static const char *get_fw_name(struct i2c_client *client)
+{
+	struct cx25840_state *state = to_state(i2c_get_clientdata(client));
+
+	if (firmware[0])
+		return firmware;
+	if (is_cx2388x(state))
+		return CX2388x_FIRMWARE;
+	if (is_cx231xx(state))
+		return CX231xx_FIRMWARE;
+	return CX25840_FIRMWARE;
+}
+
+static int check_fw_load(struct i2c_client *client, int size)
+{
+	/* DL_ADDR_HB DL_ADDR_LB */
+	int s = cx25840_read(client, 0x801) << 8;
+	s |= cx25840_read(client, 0x800);
+
+	if (size != s) {
+		v4l_err(client, "firmware %s load failed\n",
+				get_fw_name(client));
+		return -EINVAL;
+	}
+
+	v4l_info(client, "loaded %s firmware (%d bytes)\n",
+			get_fw_name(client), size);
+	return 0;
+}
+
+static int fw_write(struct i2c_client *client, const u8 *data, int size)
+{
+	if (i2c_master_send(client, data, size) < size) {
+		v4l_err(client, "firmware load i2c failure\n");
+		return -ENOSYS;
+	}
+
+	return 0;
+}
+
+int cx25840_loadfw(struct i2c_client *client)
+{
+	struct cx25840_state *state = to_state(i2c_get_clientdata(client));
+	const struct firmware *fw = NULL;
+	u8 buffer[FWSEND];
+	const u8 *ptr;
+	const char *fwname = get_fw_name(client);
+	int size, retval;
+	int max_buf_size = FWSEND;
+	u32 gpio_oe = 0, gpio_da = 0;
+
+	if (is_cx2388x(state)) {
+		/* Preserve the GPIO OE and output bits */
+		gpio_oe = cx25840_read(client, 0x160);
+		gpio_da = cx25840_read(client, 0x164);
+	}
+
+	/* cx231xx cannot accept more than 16 bytes at a time */
+	if (is_cx231xx(state) && max_buf_size > 16)
+		max_buf_size = 16;
+
+	if (request_firmware(&fw, fwname, FWDEV(client)) != 0) {
+		v4l_err(client, "unable to open firmware %s\n", fwname);
+		return -EINVAL;
+	}
+
+	start_fw_load(client);
+
+	buffer[0] = 0x08;
+	buffer[1] = 0x02;
+
+	size = fw->size;
+	ptr = fw->data;
+	while (size > 0) {
+		int len = min(max_buf_size - 2, size);
+
+		memcpy(buffer + 2, ptr, len);
+
+		retval = fw_write(client, buffer, len + 2);
+
+		if (retval < 0) {
+			release_firmware(fw);
+			return retval;
+		}
+
+		size -= len;
+		ptr += len;
+	}
+
+	end_fw_load(client);
+
+	size = fw->size;
+	release_firmware(fw);
+
+	if (is_cx2388x(state)) {
+		/* Restore GPIO configuration after f/w load */
+		cx25840_write(client, 0x160, gpio_oe);
+		cx25840_write(client, 0x164, gpio_da);
+	}
+
+	return check_fw_load(client, size);
+}
+
+MODULE_FIRMWARE(CX2388x_FIRMWARE);
+MODULE_FIRMWARE(CX231xx_FIRMWARE);
+MODULE_FIRMWARE(CX25840_FIRMWARE);
+