On 15/05/2020 04:51, Jeff Chase wrote:
> Add a CEC device driver for the Chrontel ch7322 CEC conroller.
> This is an I2C device capable of sending and receiving CEC messages.
>
> Signed-off-by: Jeff Chase <jnchase@xxxxxxxxxx>
> ---
> MAINTAINERS | 1 +
> drivers/media/cec/Kconfig | 1 +
> drivers/media/cec/Makefile | 2 +-
> drivers/media/cec/i2c/Kconfig | 14 +
> drivers/media/cec/i2c/Makefile | 5 +
> drivers/media/cec/i2c/ch7322.c | 499 +++++++++++++++++++++++++++++++++
> 6 files changed, 521 insertions(+), 1 deletion(-)
> create mode 100644 drivers/media/cec/i2c/Kconfig
> create mode 100644 drivers/media/cec/i2c/Makefile
> create mode 100644 drivers/media/cec/i2c/ch7322.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 34c6d30e61e5..43e876395686 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -4053,6 +4053,7 @@ L: linux-media@xxxxxxxxxxxxxxx
> S: Maintained
> T: git git://linuxtv.org/media_tree.git
> F: Documentation/devicetree/bindings/media/i2c/chontel,ch7322.yaml
> +F: drivers/media/cec/i2c/ch7322.c
>
> CIRRUS LOGIC AUDIO CODEC DRIVERS
> M: James Schulman <james.schulman@xxxxxxxxxx>
> diff --git a/drivers/media/cec/Kconfig b/drivers/media/cec/Kconfig
> index eea74b7cfa8c..3e934aa239ab 100644
> --- a/drivers/media/cec/Kconfig
> +++ b/drivers/media/cec/Kconfig
> @@ -33,6 +33,7 @@ menuconfig MEDIA_CEC_SUPPORT
> adapter that supports HDMI CEC.
>
> if MEDIA_CEC_SUPPORT
> +source "drivers/media/cec/i2c/Kconfig"
> source "drivers/media/cec/platform/Kconfig"
> source "drivers/media/cec/usb/Kconfig"
> endif
> diff --git a/drivers/media/cec/Makefile b/drivers/media/cec/Makefile
> index 74e80e1b3571..23539339bc81 100644
> --- a/drivers/media/cec/Makefile
> +++ b/drivers/media/cec/Makefile
> @@ -1,2 +1,2 @@
> # SPDX-License-Identifier: GPL-2.0
> -obj-y += core/ platform/ usb/
> +obj-y += core/ i2c/ platform/ usb/
> diff --git a/drivers/media/cec/i2c/Kconfig b/drivers/media/cec/i2c/Kconfig
> new file mode 100644
> index 000000000000..e445ca2110b3
> --- /dev/null
> +++ b/drivers/media/cec/i2c/Kconfig
> @@ -0,0 +1,14 @@
> +# SPDX-License-Identifier: GPL-2.0
> +#
> +# I2C drivers
> +
> +config CEC_CH7322
> + tristate "Chrontel CH7322 CEC controller"
> + select I2C
> + select REGMAP_I2C
> + select CEC_CORE
> + help
> + This is a driver for the Chrontel CH7322 CEC controller. It uses the
> + generic CEC framework interface.
> + CEC bus is present in the HDMI connector and enables communication
> + between compatible devices.
> diff --git a/drivers/media/cec/i2c/Makefile b/drivers/media/cec/i2c/Makefile
> new file mode 100644
> index 000000000000..d7496dfd0fa4
> --- /dev/null
> +++ b/drivers/media/cec/i2c/Makefile
> @@ -0,0 +1,5 @@
> +# SPDX-License-Identifier: GPL-2.0
> +#
> +# Makefile for the CEC I2C device drivers.
> +#
> +obj-$(CONFIG_CEC_CH7322) += ch7322.o
> diff --git a/drivers/media/cec/i2c/ch7322.c b/drivers/media/cec/i2c/ch7322.c
> new file mode 100644
> index 000000000000..40bc87ae5282
> --- /dev/null
> +++ b/drivers/media/cec/i2c/ch7322.c
> @@ -0,0 +1,499 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Driver for the Chrontel CH7322 CEC Controller
> + *
> + * Copyright 2020 Google LLC.
> + */
> +
> +/*
> + * Notes
> + *
> + * - This device powers on in Auto Mode which has limited functionality. This
> + * driver disables Auto Mode when it attaches.
> + *
> + */
> +
> +#include <linux/cec.h>
> +#include <linux/i2c.h>
> +#include <linux/interrupt.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/regmap.h>
> +#include <media/cec.h>
> +
> +#define CH7322_WRITE 0x00
> +#define CH7322_WRITE_MSENT 0x80
> +#define CH7322_WRITE_BOK 0x40
> +#define CH7322_WRITE_NMASK 0x0F
The coding style is to use lowercase for hex values. So 0x0f in this case.
> +
> +/* Write buffer is 0x01-0x10 */
> +#define CH7322_WRBUF 0x01
> +#define CH7322_WRBUF_LEN 0x10
> +
> +#define CH7322_READ 0x40
> +#define CH7322_READ_NRDT 0x80
> +#define CH7322_READ_MSENT 0x20
> +#define CH7322_READ_NMASK 0x0F
> +
> +/* Read buffer is 0x41-0x50 */
> +#define CH7322_RDBUF 0x41
> +#define CH7322_RDBUF_LEN 0x10
> +
> +#define CH7322_MODE 0x11
> +#define CH7322_MODE_AUTO 0x78
> +#define CH7322_MODE_SW 0xB5
> +
> +#define CH7322_RESET 0x12
> +#define CH7322_POWER 0x13
> +
> +#define CH7322_CFG0 0x17
> +#define CH7322_CFG0_EOBEN 0x40
> +#define CH7322_CFG0_PEOB 0x20
> +#define CH7322_CFG0_CLRSPP 0x10
> +#define CH7322_CFG0_FLOW 0x08
> +
> +#define CH7322_CFG1 0x1A
> +#define CH7322_CFG1_STDBYO 0x04
> +#define CH7322_CFG1_HPBP 0x02
> +#define CH7322_CFG1_PIO 0x01
> +
> +#define CH7322_INTCTL 0x1B
> +#define CH7322_INTCTL_INTPB 0x80
> +#define CH7322_INTCTL_STDBY 0x40
> +#define CH7322_INTCTL_HPDFALL 0x20
> +#define CH7322_INTCTL_HPDRISE 0x10
> +#define CH7322_INTCTL_RXMSG 0x08
> +#define CH7322_INTCTL_TXMSG 0x04
> +#define CH7322_INTCTL_NEWPHA 0x02
> +#define CH7322_INTCTL_ERROR 0x01
> +
> +#define CH7322_DVCLKFNH 0x1D
> +#define CH7322_DVCLKFNL 0x1E
> +
> +#define CH7322_CTL 0x31
> +#define CH7322_CTL_FSTDBY 0x80
> +#define CH7322_CTL_PLSEN 0x40
> +#define CH7322_CTL_PLSPB 0x20
> +#define CH7322_CTL_SPADL 0x10
> +#define CH7322_CTL_HINIT 0x08
> +#define CH7322_CTL_WPHYA 0x04
> +#define CH7322_CTL_H1T 0x02
> +#define CH7322_CTL_S1T 0x01
> +
> +#define CH7322_PAWH 0x32
> +#define CH7322_PAWL 0x33
> +
> +#define CH7322_ADDLW 0x34
> +#define CH7322_ADDLW_MASK 0xF0
> +
> +#define CH7322_ADDLR 0x3D
> +#define CH7322_ADDLR_HPD 0x80
> +#define CH7322_ADDLR_MASK 0x0F
> +
> +#define CH7322_INTDATA 0x3E
> +#define CH7322_INTDATA_MODE 0x80
> +#define CH7322_INTDATA_STDBY 0x40
> +#define CH7322_INTDATA_HPDFALL 0x20
> +#define CH7322_INTDATA_HPDRISE 0x10
> +#define CH7322_INTDATA_RXMSG 0x08
> +#define CH7322_INTDATA_TXMSG 0x04
> +#define CH7322_INTDATA_NEWPHA 0x02
> +#define CH7322_INTDATA_ERROR 0x01
> +
> +#define CH7322_EVENT 0x3F
> +#define CH7322_EVENT_TXERR 0x80
> +#define CH7322_EVENT_HRST 0x40
> +#define CH7322_EVENT_HFST 0x20
> +#define CH7322_EVENT_PHACHG 0x10
> +#define CH7322_EVENT_ACTST 0x08
> +#define CH7322_EVENT_PHARDY 0x04
> +#define CH7322_EVENT_BSOK 0x02
> +#define CH7322_EVENT_ERRADCF 0x01
> +
> +#define CH7322_DID 0x51
> +#define CH7322_DID_CH7322 0x5B
> +#define CH7322_DID_CH7323 0x5F
> +
> +#define CH7322_REVISIONID 0x52
> +
> +#define CH7322_PARH 0x53
> +#define CH7322_PARL 0x54
> +
> +#define CH7322_IOCFG2 0x75
> +#define CH7322_IOCFG_CIO 0x80
> +#define CH7322_IOCFG_IOCFGMASK 0x78
> +#define CH7322_IOCFG_AUDIO 0x04
> +#define CH7322_IOCFG_SPAMST 0x02
> +#define CH7322_IOCFG_SPAMSP 0x01
> +
> +#define CH7322_CTL3 0x7B
> +#define CH7322_CTL3_SWENA 0x80
> +#define CH7322_CTL3_FC_INIT 0x40
> +#define CH7322_CTL3_SML_FL 0x20
> +#define CH7322_CTL3_SM_RDST 0x10
> +#define CH7322_CTL3_SPP_CIAH 0x08
> +#define CH7322_CTL3_SPP_CIAL 0x04
> +#define CH7322_CTL3_SPP_ACTH 0x02
> +#define CH7322_CTL3_SPP_ACTL 0x01
> +
> +/* BOK status means NACK */
> +#define CH7322_TX_FLAG_NACK BIT(0)
> +/* Device will retry automatically */
> +#define CH7322_TX_FLAG_RETRY BIT(1)
> +
> +struct ch7322 {
> + struct i2c_client *i2c;
> + struct regmap *regmap;
> + struct cec_adapter *cec;
> + struct mutex mutex; /* device access mutex */
> + u8 tx_flags;
> +};
> +
> +static const struct regmap_config ch7322_regmap = {
> + .reg_bits = 8,
> + .val_bits = 8,
> + .max_register = 0x7F,
> + .disable_locking = true,
> +};
> +
> +static int ch7322_send_message(struct ch7322 *ch7322, const struct cec_msg *msg)
> +{
> + unsigned int val;
> + unsigned int len = msg->len;
> + int ret;
> + int i;
> +
> + WARN_ON(!mutex_is_locked(&ch7322->mutex));
> +
> + if (len > CH7322_WRBUF_LEN || len < 1)
> + return -EINVAL;
> +
> + ret = regmap_read(ch7322->regmap, CH7322_WRITE, &val);
> + if (ret)
> + return ret;
> +
> + /* Buffer not ready */
> + if (!(val & CH7322_WRITE_MSENT))
> + return -EBUSY;
> +
> + if (cec_msg_opcode(msg) == -1 &&
> + cec_msg_initiator(msg) == cec_msg_destination(msg)) {
> + ch7322->tx_flags = CH7322_TX_FLAG_NACK | CH7322_TX_FLAG_RETRY;
> + } else if (cec_msg_is_broadcast(msg)) {
> + ch7322->tx_flags = CH7322_TX_FLAG_NACK;
> + } else {
> + ch7322->tx_flags = CH7322_TX_FLAG_RETRY;
> + }
> +
> + ret = regmap_write(ch7322->regmap, CH7322_WRITE, len - 1);
> + if (ret)
> + return ret;
> +
> + for (i = 0; i < len; i++) {
> + ret = regmap_write(ch7322->regmap,
> + CH7322_WRBUF + i, msg->msg[i]);
> + if (ret)
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int ch7322_receive_message(struct ch7322 *ch7322, struct cec_msg *msg)
> +{
> + unsigned int val;
> + int ret = 0;
> + int i;
> +
> + WARN_ON(!mutex_is_locked(&ch7322->mutex));
> +
> + ret = regmap_read(ch7322->regmap, CH7322_READ, &val);
> + if (ret)
> + return ret;
> +
> + /* Message not ready */
> + if (!(val & CH7322_READ_NRDT))
> + return -EIO;
> +
> + msg->len = (val & CH7322_READ_NMASK) + 1;
> +
> + /* Read entire RDBUF to clear state */
> + for (i = 0; i < CH7322_RDBUF_LEN; i++) {
> + ret = regmap_read(ch7322->regmap, CH7322_RDBUF + i, &val);
> + if (ret)
> + return ret;
> + msg->msg[i] = (u8)val;
> + }
> +
> + return 0;
> +}
> +
> +static void ch7322_tx_done(struct ch7322 *ch7322)
> +{
> + int ret;
> + unsigned int val;
> + u8 status, flags;
> +
> + mutex_lock(&ch7322->mutex);
> + ret = regmap_read(ch7322->regmap, CH7322_WRITE, &val);
> + flags = ch7322->tx_flags;
> + mutex_unlock(&ch7322->mutex);
> +
> + /*
> + * The device returns a one-bit OK status which usually means ACK but
> + * actually means NACK when sending a logical address query or a
> + * broadcast.
> + */
> + if (ret)
> + status = CEC_TX_STATUS_ERROR;
> + else if ((val & CH7322_WRITE_BOK) && (flags & CH7322_TX_FLAG_NACK))
> + status = CEC_TX_STATUS_NACK;
> + else if (val & CH7322_WRITE_BOK)
> + status = CEC_TX_STATUS_OK;
> + else if (flags & CH7322_TX_FLAG_NACK)
> + status = CEC_TX_STATUS_OK;
> + else
> + status = CEC_TX_STATUS_NACK;
> +
> + if (status == CEC_TX_STATUS_NACK && (flags & CH7322_TX_FLAG_RETRY))
> + status |= CEC_TX_STATUS_MAX_RETRIES;
> +
> + cec_transmit_attempt_done(ch7322->cec, status);
> +}
> +
> +static void ch7322_rx_done(struct ch7322 *ch7322)
> +{
> + struct cec_msg msg;
> + int ret;
> +
> + mutex_lock(&ch7322->mutex);
> + ret = ch7322_receive_message(ch7322, &msg);
> + mutex_unlock(&ch7322->mutex);
> +
> + if (ret)
> + dev_err(&ch7322->i2c->dev, "cec receive error: %d\n", ret);
> + else
> + cec_received_msg(ch7322->cec, &msg);
> +}
> +
> +/*
> + * This device can either monitor the DDC lines to obtain the physical address
> + * or it can allow the host to program it. This driver lets the device obtain
> + * it.
> + */
> +static void ch7322_phys_addr(struct ch7322 *ch7322)
> +{
> + unsigned int pah, pal;
> + int ret = 0;
> +
> + mutex_lock(&ch7322->mutex);
> + ret |= regmap_read(ch7322->regmap, CH7322_PARH, &pah);
> + ret |= regmap_read(ch7322->regmap, CH7322_PARL, &pal);
> + mutex_unlock(&ch7322->mutex);
> +
> + if (ret)
> + dev_err(&ch7322->i2c->dev, "phys addr error\n");
> + else
> + cec_s_phys_addr(ch7322->cec, pal | (pah << 8), false);
> +}
> +
> +static void ch7322_handle_events(struct ch7322 *ch7322)
> +{
> + unsigned int data = 0;
> +
> + mutex_lock(&ch7322->mutex);
> + regmap_read(ch7322->regmap, CH7322_INTDATA, &data);
> + regmap_write(ch7322->regmap, CH7322_INTDATA, data);
> + mutex_unlock(&ch7322->mutex);
> +
> + if (data & CH7322_INTDATA_HPDFALL)
> + cec_phys_addr_invalidate(ch7322->cec);
> +
> + if (data & CH7322_INTDATA_TXMSG)
> + ch7322_tx_done(ch7322);
> +
> + if (data & CH7322_INTDATA_RXMSG)
> + ch7322_rx_done(ch7322);
> +
> + if (data & CH7322_INTDATA_NEWPHA)
> + ch7322_phys_addr(ch7322);
> +
> + if (data & CH7322_INTDATA_ERROR)
> + dev_dbg(&ch7322->i2c->dev, "unknown error\n");
> +}
> +
> +static irqreturn_t ch7322_irq(int irq, void *dev)
> +{
> + struct ch7322 *ch7322 = dev;
> +
> + ch7322_handle_events(ch7322);
> +
> + return IRQ_HANDLED;
> +}
> +
> +/* This device is always enabled */
> +static int ch7322_cec_adap_enable(struct cec_adapter *adap, bool enable)
> +{
I'd disable the interrupt here if enable is false.
There is a power down mode as well, so perhaps that's something that can be
done here too.
> + return 0;
> +}
> +
> +static int ch7322_cec_adap_log_addr(struct cec_adapter *adap, u8 log_addr)
> +{
> + struct ch7322 *ch7322 = cec_get_drvdata(adap);
> + int ret;
> +
> + mutex_lock(&ch7322->mutex);
> + ret = regmap_update_bits(ch7322->regmap, CH7322_ADDLW,
> + CH7322_ADDLW_MASK, log_addr << 4);
> + mutex_unlock(&ch7322->mutex);
If log_addr is CEC_LOG_ADDR_INVALID, then that means that the current
logical address configuration is to be cleared. In this case the logical
address is set to 0xf (unregistered/broadcast). That should mean that the
CEC device will not Ack any logical addresses, correct?
But it does receive broadcast messages and (I think) also messages from
other logical addresses, except that those will not be Acked by this
CEC adapter.
If it still receives messages from other LAs, then that means that you can
add the CEC_CAP_MONITOR_ALL capability. I.e., 'sudo cec-ctl -M' without
configuring anything should see all CEC traffic.
What is the default value of CH7322_ADDLW? It should start with 0xf as
the logical address (i.e. no received messages should be Acked).
Regards,
Hans
> +
> + return ret;
> +}
> +
> +static int ch7322_cec_adap_transmit(struct cec_adapter *adap, u8 attempts,
> + u32 signal_free_time, struct cec_msg *msg)
> +{
> + struct ch7322 *ch7322 = cec_get_drvdata(adap);
> + int ret;
> +
> + mutex_lock(&ch7322->mutex);
> + ret = ch7322_send_message(ch7322, msg);
> + mutex_unlock(&ch7322->mutex);
> +
> + return ret;
> +}
> +
> +static const struct cec_adap_ops ch7322_cec_adap_ops = {
> + .adap_enable = ch7322_cec_adap_enable,
> + .adap_log_addr = ch7322_cec_adap_log_addr,
> + .adap_transmit = ch7322_cec_adap_transmit,
> +};
> +
> +static int ch7322_probe(struct i2c_client *client)
> +{
> + struct ch7322 *ch7322;
> + int ret;
> + unsigned int val;
> +
> + ch7322 = devm_kzalloc(&client->dev, sizeof(*ch7322), GFP_KERNEL);
> + if (!ch7322)
> + return -ENOMEM;
> +
> + ch7322->regmap = devm_regmap_init_i2c(client, &ch7322_regmap);
> + if (IS_ERR(ch7322->regmap))
> + return PTR_ERR(ch7322->regmap);
> +
> + ret = regmap_read(ch7322->regmap, CH7322_DID, &val);
> + if (ret)
> + return ret;
> +
> + if (val != CH7322_DID_CH7322)
> + return -ENOTSUPP;
> +
> + mutex_init(&ch7322->mutex);
> + ch7322->i2c = client;
> + ch7322->tx_flags = 0;
> +
> + i2c_set_clientdata(client, ch7322);
> +
> + /* Disable auto mode */
> + ret = regmap_write(ch7322->regmap, CH7322_MODE, CH7322_MODE_SW);
> + if (ret)
> + goto err_mutex;
> +
> + /* Enable logical address register */
> + ret = regmap_update_bits(ch7322->regmap, CH7322_CTL,
> + CH7322_CTL_SPADL, CH7322_CTL_SPADL);
> + if (ret)
> + goto err_mutex;
> +
> + ch7322->cec = cec_allocate_adapter(&ch7322_cec_adap_ops, ch7322,
> + dev_name(&client->dev),
> + CEC_CAP_DEFAULTS, 1);
> +
> + if (IS_ERR(ch7322->cec)) {
> + ret = PTR_ERR(ch7322->cec);
> + goto err_mutex;
> + }
> +
> + ret = cec_register_adapter(ch7322->cec, &client->dev);
> + if (ret) {
> + cec_delete_adapter(ch7322->cec);
> + goto err_mutex;
> + }
> +
> + /* Configure and mask interrupt */
> + ret = regmap_write(ch7322->regmap, CH7322_CFG1, 0);
> + if (ret)
> + goto err_cec;
> +
> + ret = regmap_write(ch7322->regmap, CH7322_INTCTL, CH7322_INTCTL_INTPB);
> + if (ret)
> + goto err_cec;
> +
> + ret = devm_request_threaded_irq(&client->dev, client->irq, NULL,
> + ch7322_irq,
> + IRQF_ONESHOT | IRQF_TRIGGER_RISING,
> + client->name, ch7322);
> + if (ret)
> + goto err_cec;
> +
> + ch7322_handle_events(ch7322);
> +
> + /* Unmask interrupt */
> + mutex_lock(&ch7322->mutex);
> + ret = regmap_write(ch7322->regmap, CH7322_INTCTL, 0xff);
> + mutex_unlock(&ch7322->mutex);
> +
> + if (ret)
> + goto err_cec;
> +
> + dev_info(&client->dev, "device registered\n");
> +
> + return 0;
> +
> +err_cec:
> + cec_unregister_adapter(ch7322->cec);
> +
> +err_mutex:
> + mutex_destroy(&ch7322->mutex);
> + return ret;
> +}
> +
> +static int ch7322_remove(struct i2c_client *client)
> +{
> + struct ch7322 *ch7322 = i2c_get_clientdata(client);
> +
> + /* Mask interrupt */
> + mutex_lock(&ch7322->mutex);
> + regmap_write(ch7322->regmap, CH7322_INTCTL, CH7322_INTCTL_INTPB);
> + mutex_unlock(&ch7322->mutex);
> +
> + cec_unregister_adapter(ch7322->cec);
> + mutex_destroy(&ch7322->mutex);
> +
> + dev_info(&client->dev, "device unregistered\n");
> +
> + return 0;
> +}
> +
> +static const struct of_device_id ch7322_of_match[] = {
> + { .compatible = "chrontel,ch7322", },
> + {},
> +};
> +MODULE_DEVICE_TABLE(of, ch7322_of_match);
> +
> +static struct i2c_driver ch7322_i2c_driver = {
> + .driver = {
> + .name = "ch7322",
> + .of_match_table = of_match_ptr(ch7322_of_match),
> + },
> + .probe_new = ch7322_probe,
> + .remove = ch7322_remove,
> +};
> +
> +module_i2c_driver(ch7322_i2c_driver);
> +
> +MODULE_DESCRIPTION("Chrontel CH7322 CEC Controller Driver");
> +MODULE_AUTHOR("Jeff Chase <jnchase@xxxxxxxxxx>");
> +MODULE_LICENSE("GPL");
>
