1 files changed, 334 insertions, 0 deletions
diff --git a/drivers/staging/media/solo6x10/solo6x10-i2c.c b/drivers/staging/media/solo6x10/solo6x10-i2c.c
new file mode 100644
index 000000000000..01aa417c9258
--- /dev/null
+++ b/drivers/staging/media/solo6x10/solo6x10-i2c.c
@@ -0,0 +1,334 @@
+/*
+ * Copyright (C) 2010-2013 Bluecherry, LLC <http://www.bluecherrydvr.com>
+ *
+ * Original author:
+ * Ben Collins <bcollins@ubuntu.com>
+ *
+ * Additional work by:
+ * John Brooks <john.brooks@bluecherry.net>
+ *
+ * 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+/* XXX: The SOLO6x10 i2c does not have separate interrupts for each i2c
+ * channel. The bus can only handle one i2c event at a time. The below handles
+ * this all wrong. We should be using the status registers to see if the bus
+ * is in use, and have a global lock to check the status register. Also,
+ * the bulk of the work should be handled out-of-interrupt. The ugly loops
+ * that occur during interrupt scare me. The ISR should merely signal
+ * thread context, ACK the interrupt, and move on. -- BenC */
+
+#include <linux/kernel.h>
+
+#include "solo6x10.h"
+
+u8 solo_i2c_readbyte(struct solo_dev *solo_dev, int id, u8 addr, u8 off)
+{
+	struct i2c_msg msgs[2];
+	u8 data;
+
+	msgs[0].flags = 0;
+	msgs[0].addr = addr;
+	msgs[0].len = 1;
+	msgs[0].buf = &off;
+
+	msgs[1].flags = I2C_M_RD;
+	msgs[1].addr = addr;
+	msgs[1].len = 1;
+	msgs[1].buf = &data;
+
+	i2c_transfer(&solo_dev->i2c_adap[id], msgs, 2);
+
+	return data;
+}
+
+void solo_i2c_writebyte(struct solo_dev *solo_dev, int id, u8 addr,
+			u8 off, u8 data)
+{
+	struct i2c_msg msgs;
+	u8 buf[2];
+
+	buf[0] = off;
+	buf[1] = data;
+	msgs.flags = 0;
+	msgs.addr = addr;
+	msgs.len = 2;
+	msgs.buf = buf;
+
+	i2c_transfer(&solo_dev->i2c_adap[id], &msgs, 1);
+}
+
+static void solo_i2c_flush(struct solo_dev *solo_dev, int wr)
+{
+	u32 ctrl;
+
+	ctrl = SOLO_IIC_CH_SET(solo_dev->i2c_id);
+
+	if (solo_dev->i2c_state == IIC_STATE_START)
+		ctrl |= SOLO_IIC_START;
+
+	if (wr) {
+		ctrl |= SOLO_IIC_WRITE;
+	} else {
+		ctrl |= SOLO_IIC_READ;
+		if (!(solo_dev->i2c_msg->flags & I2C_M_NO_RD_ACK))
+			ctrl |= SOLO_IIC_ACK_EN;
+	}
+
+	if (solo_dev->i2c_msg_ptr == solo_dev->i2c_msg->len)
+		ctrl |= SOLO_IIC_STOP;
+
+	solo_reg_write(solo_dev, SOLO_IIC_CTRL, ctrl);
+}
+
+static void solo_i2c_start(struct solo_dev *solo_dev)
+{
+	u32 addr = solo_dev->i2c_msg->addr << 1;
+
+	if (solo_dev->i2c_msg->flags & I2C_M_RD)
+		addr |= 1;
+
+	solo_dev->i2c_state = IIC_STATE_START;
+	solo_reg_write(solo_dev, SOLO_IIC_TXD, addr);
+	solo_i2c_flush(solo_dev, 1);
+}
+
+static void solo_i2c_stop(struct solo_dev *solo_dev)
+{
+	solo_irq_off(solo_dev, SOLO_IRQ_IIC);
+	solo_reg_write(solo_dev, SOLO_IIC_CTRL, 0);
+	solo_dev->i2c_state = IIC_STATE_STOP;
+	wake_up(&solo_dev->i2c_wait);
+}
+
+static int solo_i2c_handle_read(struct solo_dev *solo_dev)
+{
+prepare_read:
+	if (solo_dev->i2c_msg_ptr != solo_dev->i2c_msg->len) {
+		solo_i2c_flush(solo_dev, 0);
+		return 0;
+	}
+
+	solo_dev->i2c_msg_ptr = 0;
+	solo_dev->i2c_msg++;
+	solo_dev->i2c_msg_num--;
+
+	if (solo_dev->i2c_msg_num == 0) {
+		solo_i2c_stop(solo_dev);
+		return 0;
+	}
+
+	if (!(solo_dev->i2c_msg->flags & I2C_M_NOSTART)) {
+		solo_i2c_start(solo_dev);
+	} else {
+		if (solo_dev->i2c_msg->flags & I2C_M_RD)
+			goto prepare_read;
+		else
+			solo_i2c_stop(solo_dev);
+	}
+
+	return 0;
+}
+
+static int solo_i2c_handle_write(struct solo_dev *solo_dev)
+{
+retry_write:
+	if (solo_dev->i2c_msg_ptr != solo_dev->i2c_msg->len) {
+		solo_reg_write(solo_dev, SOLO_IIC_TXD,
+			       solo_dev->i2c_msg->buf[solo_dev->i2c_msg_ptr]);
+		solo_dev->i2c_msg_ptr++;
+		solo_i2c_flush(solo_dev, 1);
+		return 0;
+	}
+
+	solo_dev->i2c_msg_ptr = 0;
+	solo_dev->i2c_msg++;
+	solo_dev->i2c_msg_num--;
+
+	if (solo_dev->i2c_msg_num == 0) {
+		solo_i2c_stop(solo_dev);
+		return 0;
+	}
+
+	if (!(solo_dev->i2c_msg->flags & I2C_M_NOSTART)) {
+		solo_i2c_start(solo_dev);
+	} else {
+		if (solo_dev->i2c_msg->flags & I2C_M_RD)
+			solo_i2c_stop(solo_dev);
+		else
+			goto retry_write;
+	}
+
+	return 0;
+}
+
+int solo_i2c_isr(struct solo_dev *solo_dev)
+{
+	u32 status = solo_reg_read(solo_dev, SOLO_IIC_CTRL);
+	int ret = -EINVAL;
+
+
+	if (CHK_FLAGS(status, SOLO_IIC_STATE_TRNS | SOLO_IIC_STATE_SIG_ERR)
+	    || solo_dev->i2c_id < 0) {
+		solo_i2c_stop(solo_dev);
+		return -ENXIO;
+	}
+
+	switch (solo_dev->i2c_state) {
+	case IIC_STATE_START:
+		if (solo_dev->i2c_msg->flags & I2C_M_RD) {
+			solo_dev->i2c_state = IIC_STATE_READ;
+			ret = solo_i2c_handle_read(solo_dev);
+			break;
+		}
+
+		solo_dev->i2c_state = IIC_STATE_WRITE;
+	case IIC_STATE_WRITE:
+		ret = solo_i2c_handle_write(solo_dev);
+		break;
+
+	case IIC_STATE_READ:
+		solo_dev->i2c_msg->buf[solo_dev->i2c_msg_ptr] =
+			solo_reg_read(solo_dev, SOLO_IIC_RXD);
+		solo_dev->i2c_msg_ptr++;
+
+		ret = solo_i2c_handle_read(solo_dev);
+		break;
+
+	default:
+		solo_i2c_stop(solo_dev);
+	}
+
+	return ret;
+}
+
+static int solo_i2c_master_xfer(struct i2c_adapter *adap,
+				struct i2c_msg msgs[], int num)
+{
+	struct solo_dev *solo_dev = adap->algo_data;
+	unsigned long timeout;
+	int ret;
+	int i;
+	DEFINE_WAIT(wait);
+
+	for (i = 0; i < SOLO_I2C_ADAPTERS; i++) {
+		if (&solo_dev->i2c_adap[i] == adap)
+			break;
+	}
+
+	if (i == SOLO_I2C_ADAPTERS)
+		return num; /* XXX Right return value for failure? */
+
+	mutex_lock(&solo_dev->i2c_mutex);
+	solo_dev->i2c_id = i;
+	solo_dev->i2c_msg = msgs;
+	solo_dev->i2c_msg_num = num;
+	solo_dev->i2c_msg_ptr = 0;
+
+	solo_reg_write(solo_dev, SOLO_IIC_CTRL, 0);
+	solo_irq_on(solo_dev, SOLO_IRQ_IIC);
+	solo_i2c_start(solo_dev);
+
+	timeout = HZ / 2;
+
+	for (;;) {
+		prepare_to_wait(&solo_dev->i2c_wait, &wait,
+				TASK_INTERRUPTIBLE);
+
+		if (solo_dev->i2c_state == IIC_STATE_STOP)
+			break;
+
+		timeout = schedule_timeout(timeout);
+		if (!timeout)
+			break;
+
+		if (signal_pending(current))
+			break;
+	}
+
+	finish_wait(&solo_dev->i2c_wait, &wait);
+	ret = num - solo_dev->i2c_msg_num;
+	solo_dev->i2c_state = IIC_STATE_IDLE;
+	solo_dev->i2c_id = -1;
+
+	mutex_unlock(&solo_dev->i2c_mutex);
+
+	return ret;
+}
+
+static u32 solo_i2c_functionality(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C;
+}
+
+static const struct i2c_algorithm solo_i2c_algo = {
+	.master_xfer	= solo_i2c_master_xfer,
+	.functionality	= solo_i2c_functionality,
+};
+
+int solo_i2c_init(struct solo_dev *solo_dev)
+{
+	int i;
+	int ret;
+
+	solo_reg_write(solo_dev, SOLO_IIC_CFG,
+		       SOLO_IIC_PRESCALE(8) | SOLO_IIC_ENABLE);
+
+	solo_dev->i2c_id = -1;
+	solo_dev->i2c_state = IIC_STATE_IDLE;
+	init_waitqueue_head(&solo_dev->i2c_wait);
+	mutex_init(&solo_dev->i2c_mutex);
+
+	for (i = 0; i < SOLO_I2C_ADAPTERS; i++) {
+		struct i2c_adapter *adap = &solo_dev->i2c_adap[i];
+
+		snprintf(adap->name, I2C_NAME_SIZE, "%s I2C %d",
+			 SOLO6X10_NAME, i);
+		adap->algo = &solo_i2c_algo;
+		adap->algo_data = solo_dev;
+		adap->retries = 1;
+		adap->dev.parent = &solo_dev->pdev->dev;
+
+		ret = i2c_add_adapter(adap);
+		if (ret) {
+			adap->algo_data = NULL;
+			break;
+		}
+	}
+
+	if (ret) {
+		for (i = 0; i < SOLO_I2C_ADAPTERS; i++) {
+			if (!solo_dev->i2c_adap[i].algo_data)
+				break;
+			i2c_del_adapter(&solo_dev->i2c_adap[i]);
+			solo_dev->i2c_adap[i].algo_data = NULL;
+		}
+		return ret;
+	}
+
+	return 0;
+}
+
+void solo_i2c_exit(struct solo_dev *solo_dev)
+{
+	int i;
+
+	for (i = 0; i < SOLO_I2C_ADAPTERS; i++) {
+		if (!solo_dev->i2c_adap[i].algo_data)
+			continue;
+		i2c_del_adapter(&solo_dev->i2c_adap[i]);
+		solo_dev->i2c_adap[i].algo_data = NULL;
+	}
+}