[media] cobalt: add new driver

The cobalt device is a PCIe card with 4 HDMI inputs (adv7604) and a
connector that can be used to hook up an adv7511 transmitter or an
adv7842 receiver daughterboard.

This device is used within Cisco but is sadly not available outside
of Cisco. Nevertheless it is a very interesting driver that can serve
as an example of how to support HDMI hardware and how to use the popular
adv devices.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

1 files changed, 396 insertions, 0 deletions

diff --git a/drivers/media/pci/cobalt/cobalt-i2c.c b/drivers/media/pci/cobalt/cobalt-i2c.c
new file mode 100644
index 0000000..57b330f
--- /dev/null
+++ b/drivers/media/pci/cobalt/cobalt-i2c.c
@@ -0,0 +1,396 @@
+/*
+ *  cobalt I2C functions
+ *
+ *  Derived from cx18-i2c.c
+ *
+ *  Copyright 2012-2015 Cisco Systems, Inc. and/or its affiliates.
+ *  All rights reserved.
+ *
+ *  This program is free software; you may redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; version 2 of the License.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ *  BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ *  ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ *  CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ *  SOFTWARE.
+ */
+
+#include "cobalt-driver.h"
+#include "cobalt-i2c.h"
+
+struct cobalt_i2c_regs {
+	/* Clock prescaler register lo-byte */
+	u8 prerlo;
+	u8 dummy0[3];
+	/* Clock prescaler register high-byte */
+	u8 prerhi;
+	u8 dummy1[3];
+	/* Control register */
+	u8 ctr;
+	u8 dummy2[3];
+	/* Transmit/Receive register */
+	u8 txr_rxr;
+	u8 dummy3[3];
+	/* Command and Status register */
+	u8 cr_sr;
+	u8 dummy4[3];
+};
+
+/* CTR[7:0] - Control register */
+
+/* I2C Core enable bit */
+#define M00018_CTR_BITMAP_EN_MSK	(1 << 7)
+
+/* I2C Core interrupt enable bit */
+#define M00018_CTR_BITMAP_IEN_MSK	(1 << 6)
+
+/* CR[7:0] - Command register */
+
+/* I2C start condition */
+#define M00018_CR_BITMAP_STA_MSK	(1 << 7)
+
+/* I2C stop condition */
+#define M00018_CR_BITMAP_STO_MSK	(1 << 6)
+
+/* I2C read from slave */
+#define M00018_CR_BITMAP_RD_MSK		(1 << 5)
+
+/* I2C write to slave */
+#define M00018_CR_BITMAP_WR_MSK		(1 << 4)
+
+/* I2C ack */
+#define M00018_CR_BITMAP_ACK_MSK	(1 << 3)
+
+/* I2C Interrupt ack */
+#define M00018_CR_BITMAP_IACK_MSK	(1 << 0)
+
+/* SR[7:0] - Status register */
+
+/* Receive acknowledge from slave */
+#define M00018_SR_BITMAP_RXACK_MSK	(1 << 7)
+
+/* Busy, I2C bus busy (as defined by start / stop bits) */
+#define M00018_SR_BITMAP_BUSY_MSK	(1 << 6)
+
+/* Arbitration lost - core lost arbitration */
+#define M00018_SR_BITMAP_AL_MSK		(1 << 5)
+
+/* Transfer in progress */
+#define M00018_SR_BITMAP_TIP_MSK	(1 << 1)
+
+/* Interrupt flag */
+#define M00018_SR_BITMAP_IF_MSK		(1 << 0)
+
+/* Frequency, in Hz */
+#define I2C_FREQUENCY			400000
+#define ALT_CPU_FREQ			83333333
+
+static volatile struct cobalt_i2c_regs __iomem *
+cobalt_i2c_regs(struct cobalt *cobalt, unsigned idx)
+{
+	switch (idx) {
+	case 0:
+	default:
+		return (volatile struct cobalt_i2c_regs __iomem *)
+			(cobalt->bar1 + COBALT_I2C_0_BASE);
+	case 1:
+		return (volatile struct cobalt_i2c_regs __iomem *)
+			(cobalt->bar1 + COBALT_I2C_1_BASE);
+	case 2:
+		return (volatile struct cobalt_i2c_regs __iomem *)
+			(cobalt->bar1 + COBALT_I2C_2_BASE);
+	case 3:
+		return (volatile struct cobalt_i2c_regs __iomem *)
+			(cobalt->bar1 + COBALT_I2C_3_BASE);
+	case 4:
+		return (volatile struct cobalt_i2c_regs __iomem *)
+			(cobalt->bar1 + COBALT_I2C_HSMA_BASE);
+	}
+}
+
+/* Do low-level i2c byte transfer.
+ * Returns -1 in case of an error or 0 otherwise.
+ */
+static int cobalt_tx_bytes(volatile struct cobalt_i2c_regs __iomem *regs,
+		struct i2c_adapter *adap, bool start, bool stop,
+		u8 *data, u16 len)
+{
+	unsigned long start_time;
+	int status;
+	int cmd;
+	int i;
+
+	for (i = 0; i < len; i++) {
+		/* Setup data */
+		regs->txr_rxr = data[i];
+
+		/* Setup command */
+		if (i == 0 && start != 0) {
+			/* Write + Start */
+			cmd = M00018_CR_BITMAP_WR_MSK |
+			      M00018_CR_BITMAP_STA_MSK;
+		} else if (i == len - 1 && stop != 0) {
+			/* Write + Stop */
+			cmd = M00018_CR_BITMAP_WR_MSK |
+			      M00018_CR_BITMAP_STO_MSK;
+		} else {
+			/* Write only */
+			cmd = M00018_CR_BITMAP_WR_MSK;
+		}
+
+		/* Execute command */
+		regs->cr_sr = cmd;
+
+		/* Wait for transfer to complete (TIP = 0) */
+		start_time = jiffies;
+		status = regs->cr_sr;
+		while (status & M00018_SR_BITMAP_TIP_MSK) {
+			if (time_after(jiffies, start_time + adap->timeout))
+				return -ETIMEDOUT;
+			cond_resched();
+			status = regs->cr_sr;
+		}
+
+		/* Verify ACK */
+		if (status & M00018_SR_BITMAP_RXACK_MSK) {
+			/* NO ACK! */
+			return -EIO;
+		}
+
+		/* Verify arbitration */
+		if (status & M00018_SR_BITMAP_AL_MSK) {
+			/* Arbitration lost! */
+			return -EIO;
+		}
+	}
+	return 0;
+}
+
+/* Do low-level i2c byte read.
+ * Returns -1 in case of an error or 0 otherwise.
+ */
+static int cobalt_rx_bytes(volatile struct cobalt_i2c_regs __iomem *regs,
+		struct i2c_adapter *adap, bool start, bool stop,
+		u8 *data, u16 len)
+{
+	unsigned long start_time;
+	int status;
+	int cmd;
+	int i;
+
+	for (i = 0; i < len; i++) {
+		/* Setup command */
+		if (i == 0 && start != 0) {
+			/* Read + Start */
+			cmd = M00018_CR_BITMAP_RD_MSK |
+			      M00018_CR_BITMAP_STA_MSK;
+		} else if (i == len - 1 && stop != 0) {
+			/* Read + Stop */
+			cmd = M00018_CR_BITMAP_RD_MSK |
+			      M00018_CR_BITMAP_STO_MSK;
+		} else {
+			/* Read only */
+			cmd = M00018_CR_BITMAP_RD_MSK;
+		}
+
+		/* Last byte to read, no ACK */
+		if (i == len - 1)
+			cmd |= M00018_CR_BITMAP_ACK_MSK;
+
+		/* Execute command */
+		regs->cr_sr = cmd;
+
+		/* Wait for transfer to complete (TIP = 0) */
+		start_time = jiffies;
+		status = regs->cr_sr;
+		while (status & M00018_SR_BITMAP_TIP_MSK) {
+			if (time_after(jiffies, start_time + adap->timeout))
+				return -ETIMEDOUT;
+			cond_resched();
+			status = regs->cr_sr;
+		}
+
+		/* Verify arbitration */
+		if (status & M00018_SR_BITMAP_AL_MSK) {
+			/* Arbitration lost! */
+			return -EIO;
+		}
+
+		/* Store data */
+		data[i] = regs->txr_rxr;
+	}
+	return 0;
+}
+
+/* Generate stop condition on i2c bus.
+ * The m00018 stop isn't doing the right thing (wrong timing).
+ * So instead send a start condition, 8 zeroes and a stop condition.
+ */
+static int cobalt_stop(volatile struct cobalt_i2c_regs __iomem *regs,
+		struct i2c_adapter *adap)
+{
+	u8 data = 0;
+
+	return cobalt_tx_bytes(regs, adap, true, true, &data, 1);
+}
+
+static int cobalt_xfer(struct i2c_adapter *adap,
+			struct i2c_msg msgs[], int num)
+{
+	struct cobalt_i2c_data *data = adap->algo_data;
+	volatile struct cobalt_i2c_regs __iomem *regs = data->regs;
+	struct i2c_msg *pmsg;
+	unsigned short flags;
+	int ret = 0;
+	int i, j;
+
+	for (i = 0; i < num; i++) {
+		int stop = (i == num - 1);
+
+		pmsg = &msgs[i];
+		flags = pmsg->flags;
+
+		if (!(pmsg->flags & I2C_M_NOSTART)) {
+			u8 addr = pmsg->addr << 1;
+
+			if (flags & I2C_M_RD)
+				addr |= 1;
+			if (flags & I2C_M_REV_DIR_ADDR)
+				addr ^= 1;
+			for (j = 0; j < adap->retries; j++) {
+				ret = cobalt_tx_bytes(regs, adap, true, false,
+						      &addr, 1);
+				if (!ret)
+					break;
+				cobalt_stop(regs, adap);
+			}
+			if (ret < 0)
+				return ret;
+			ret = 0;
+		}
+		if (pmsg->flags & I2C_M_RD) {
+			/* read bytes into buffer */
+			ret = cobalt_rx_bytes(regs, adap, false, stop,
+					pmsg->buf, pmsg->len);
+			if (ret < 0)
+				goto bailout;
+		} else {
+			/* write bytes from buffer */
+			ret = cobalt_tx_bytes(regs, adap, false, stop,
+					pmsg->buf, pmsg->len);
+			if (ret < 0)
+				goto bailout;
+		}
+	}
+	ret = i;
+
+bailout:
+	if (ret < 0)
+		cobalt_stop(regs, adap);
+	return ret;
+}
+
+static u32 cobalt_func(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+/* template for i2c-bit-algo */
+static struct i2c_adapter cobalt_i2c_adap_template = {
+	.name = "cobalt i2c driver",
+	.algo = NULL,                   /* set by i2c-algo-bit */
+	.algo_data = NULL,              /* filled from template */
+	.owner = THIS_MODULE,
+};
+
+static const struct i2c_algorithm cobalt_algo = {
+	.master_xfer	= cobalt_xfer,
+	.functionality	= cobalt_func,
+};
+
+/* init + register i2c algo-bit adapter */
+int cobalt_i2c_init(struct cobalt *cobalt)
+{
+	int i, err;
+	int status;
+	int prescale;
+	unsigned long start_time;
+
+	cobalt_dbg(1, "i2c init\n");
+
+	/* Define I2C clock prescaler */
+	prescale = ((ALT_CPU_FREQ) / (5 * I2C_FREQUENCY)) - 1;
+
+	for (i = 0; i < COBALT_NUM_ADAPTERS; i++) {
+		volatile struct cobalt_i2c_regs __iomem *regs =
+			cobalt_i2c_regs(cobalt, i);
+		struct i2c_adapter *adap = &cobalt->i2c_adap[i];
+
+		/* Disable I2C */
+		regs->cr_sr = M00018_CTR_BITMAP_EN_MSK;
+		regs->ctr = 0;
+		regs->cr_sr = 0;
+
+		start_time = jiffies;
+		do {
+			if (time_after(jiffies, start_time + HZ)) {
+				if (cobalt_ignore_err) {
+					adap->dev.parent = NULL;
+					return 0;
+				}
+				return -ETIMEDOUT;
+			}
+			status = regs->cr_sr;
+		} while (status & M00018_SR_BITMAP_TIP_MSK);
+
+		/* Disable I2C */
+		regs->ctr = 0;
+		regs->cr_sr = 0;
+
+		/* Calculate i2c prescaler */
+		regs->prerlo = prescale & 0xff;
+		regs->prerhi = (prescale >> 8) & 0xff;
+		/* Enable I2C, interrupts disabled */
+		regs->ctr = M00018_CTR_BITMAP_EN_MSK;
+		/* Setup algorithm for adapter */
+		cobalt->i2c_data[i].cobalt = cobalt;
+		cobalt->i2c_data[i].regs = regs;
+		*adap = cobalt_i2c_adap_template;
+		adap->algo = &cobalt_algo;
+		adap->algo_data = &cobalt->i2c_data[i];
+		adap->retries = 3;
+		sprintf(adap->name + strlen(adap->name),
+				" #%d-%d", cobalt->instance, i);
+		i2c_set_adapdata(adap, &cobalt->v4l2_dev);
+		adap->dev.parent = &cobalt->pci_dev->dev;
+		err = i2c_add_adapter(adap);
+		if (err) {
+			if (cobalt_ignore_err) {
+				adap->dev.parent = NULL;
+				return 0;
+			}
+			while (i--)
+				i2c_del_adapter(&cobalt->i2c_adap[i]);
+			return err;
+		}
+		cobalt_info("registered bus %s\n", adap->name);
+	}
+	return 0;
+}
+
+void cobalt_i2c_exit(struct cobalt *cobalt)
+{
+	int i;
+
+	cobalt_dbg(1, "i2c exit\n");
+
+	for (i = 0; i < COBALT_NUM_ADAPTERS; i++) {
+		cobalt_err("unregistered bus %s\n", cobalt->i2c_adap[i].name);
+		i2c_del_adapter(&cobalt->i2c_adap[i]);
+	}
+}