Add a CEC driver for the TDA9950, which is a stand-alone I2C CEC device,
but is also integrated into HDMI transceivers such as the TDA9989 and
TDA19989.
The TDA9950 contains a command processor which handles retransmissions
and the low level bus protocol. The driver just has to read and write
the messages, and handle error conditions.
Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i2c/Kconfig | 5 +
drivers/gpu/drm/i2c/Makefile | 1 +
drivers/gpu/drm/i2c/tda9950.c | 507 ++++++++++++++++++++++++++++++++++
include/linux/platform_data/tda9950.h | 16 ++
4 files changed, 529 insertions(+)
create mode 100644 drivers/gpu/drm/i2c/tda9950.c
create mode 100644 include/linux/platform_data/tda9950.h
diff --git a/drivers/gpu/drm/i2c/Kconfig b/drivers/gpu/drm/i2c/Kconfig
index a6c92beb410a..3a232f5ff0a1 100644
--- a/drivers/gpu/drm/i2c/Kconfig
+++ b/drivers/gpu/drm/i2c/Kconfig
@@ -26,4 +26,9 @@ config DRM_I2C_NXP_TDA998X
help
Support for NXP Semiconductors TDA998X HDMI encoders.
+config DRM_I2C_NXP_TDA9950
+ tristate "NXP Semiconductors TDA9950/TDA998X HDMI CEC"
+ select CEC_NOTIFIER
+ select CEC_CORE
+
endmenu
diff --git a/drivers/gpu/drm/i2c/Makefile b/drivers/gpu/drm/i2c/Makefile
index b20100c18ffb..a962f6f08568 100644
--- a/drivers/gpu/drm/i2c/Makefile
+++ b/drivers/gpu/drm/i2c/Makefile
@@ -7,3 +7,4 @@ obj-$(CONFIG_DRM_I2C_SIL164) += sil164.o
tda998x-y := tda998x_drv.o
obj-$(CONFIG_DRM_I2C_NXP_TDA998X) += tda998x.o
+obj-$(CONFIG_DRM_I2C_NXP_TDA9950) += tda9950.o
diff --git a/drivers/gpu/drm/i2c/tda9950.c b/drivers/gpu/drm/i2c/tda9950.c
new file mode 100644
index 000000000000..6f7a37ddda05
--- /dev/null
+++ b/drivers/gpu/drm/i2c/tda9950.c
@@ -0,0 +1,507 @@
+/*
+ * TDA9950 Consumer Electronics Control driver
+ *
+ * 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.
+ *
+ * The NXP TDA9950 implements the HDMI Consumer Electronics Control
+ * interface. The host interface is similar to a mailbox: the data
+ * registers starting at REG_CDR0 are written to send a command to the
+ * internal CPU, and replies are read from these registers.
+ *
+ * As the data registers represent a mailbox, they must be accessed
+ * as a single I2C transaction. See the TDA9950 data sheet for details.
+ */
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/platform_data/tda9950.h>
+#include <linux/slab.h>
+#include <drm/drm_edid.h>
+#include <media/cec.h>
+#include <media/cec-notifier.h>
+
+enum {
+ REG_CSR = 0x00,
+ CSR_BUSY = BIT(7),
+ CSR_INT = BIT(6),
+ CSR_ERR = BIT(5),
+
+ REG_CER = 0x01,
+
+ REG_CVR = 0x02,
+
+ REG_CCR = 0x03,
+ CCR_RESET = BIT(7),
+ CCR_ON = BIT(6),
+
+ REG_ACKH = 0x04,
+ REG_ACKL = 0x05,
+
+ REG_CCONR = 0x06,
+ CCONR_ENABLE_ERROR = BIT(4),
+ CCONR_RETRY_MASK = 7,
+
+ REG_CDR0 = 0x07,
+
+ CDR1_REQ = 0x00,
+ CDR1_CNF = 0x01,
+ CDR1_IND = 0x81,
+ CDR1_ERR = 0x82,
+ CDR1_IER = 0x83,
+
+ CDR2_CNF_SUCCESS = 0x00,
+ CDR2_CNF_OFF_STATE = 0x80,
+ CDR2_CNF_BAD_REQ = 0x81,
+ CDR2_CNF_CEC_ACCESS = 0x82,
+ CDR2_CNF_ARB_ERROR = 0x83,
+ CDR2_CNF_BAD_TIMING = 0x84,
+ CDR2_CNF_NACK_ADDR = 0x85,
+ CDR2_CNF_NACK_DATA = 0x86,
+};
+
+struct tda9950_priv {
+ struct i2c_client *client;
+ struct device *hdmi;
+ struct cec_adapter *adap;
+ struct tda9950_glue *glue;
+ u16 addresses;
+ struct cec_msg rx_msg;
+ struct cec_notifier *notify;
+ bool open;
+};
+
+static int tda9950_write_range(struct i2c_client *client, u8 addr, u8 *p, int cnt)
+{
+ struct i2c_msg msg;
+ u8 buf[cnt + 1];
+ int ret;
+
+ buf[0] = addr;
+ memcpy(buf + 1, p, cnt);
+
+ msg.addr = client->addr;
+ msg.flags = 0;
+ msg.len = cnt + 1;
+ msg.buf = buf;
+
+ dev_dbg(&client->dev, "wr 0x%02x: %*ph\n", addr, cnt, p);
+
+ ret = i2c_transfer(client->adapter, &msg, 1);
+ if (ret < 0)
+ dev_err(&client->dev, "Error %d writing to cec:0x%x\n", ret, addr);
+ return ret < 0 ? ret : 0;
+}
+
+static void tda9950_write(struct i2c_client *client, u8 addr, u8 val)
+{
+ tda9950_write_range(client, addr, &val, 1);
+}
+
+static int tda9950_read_range(struct i2c_client *client, u8 addr, u8 *p, int cnt)
+{
+ struct i2c_msg msg[2];
+ int ret;
+
+ msg[0].addr = client->addr;
+ msg[0].flags = 0;
+ msg[0].len = 1;
+ msg[0].buf = &addr;
+ msg[1].addr = client->addr;
+ msg[1].flags = I2C_M_RD;
+ msg[1].len = cnt;
+ msg[1].buf = p;
+
+ ret = i2c_transfer(client->adapter, msg, 2);
+ if (ret < 0)
+ dev_err(&client->dev, "Error %d reading from cec:0x%x\n", ret, addr);
+
+ dev_dbg(&client->dev, "rd 0x%02x: %*ph\n", addr, cnt, p);
+
+ return ret;
+}
+
+static u8 tda9950_read(struct i2c_client *client, u8 addr)
+{
+ int ret;
+ u8 val;
+
+ ret = tda9950_read_range(client, addr, &val, 1);
+ if (ret < 0)
+ val = 0;
+
+ return val;
+}
+
+static irqreturn_t tda9950_irq(int irq, void *data)
+{
+ struct tda9950_priv *priv = data;
+ unsigned int tx_status;
+ u8 csr, cconr, buf[19];
+ u8 arb_lost_cnt, nack_cnt, err_cnt;
+
+ if (!priv->open)
+ return IRQ_NONE;
+
+ csr = tda9950_read(priv->client, REG_CSR);
+ if (!(csr & CSR_INT))
+ return IRQ_NONE;
+
+ cconr = tda9950_read(priv->client, REG_CCONR) & CCONR_RETRY_MASK;
+
+ tda9950_read_range(priv->client, REG_CDR0, buf, sizeof(buf));
+
+ /*
+ * This should never happen: the data sheet says that there will
+ * always be a valid message if the interrupt line is asserted.
+ */
+ if (buf[0] == 0) {
+ dev_warn(&priv->client->dev, "interrupt pending, but no message?\n");
+ return IRQ_NONE;
+ }
+
+ switch (buf[1]) {
+ case CDR1_CNF: /* transmit result */
+ arb_lost_cnt = nack_cnt = err_cnt = 0;
+ switch (buf[2]) {
+ case CDR2_CNF_SUCCESS:
+ tx_status = CEC_TX_STATUS_OK;
+ break;
+
+ case CDR2_CNF_ARB_ERROR:
+ tx_status = CEC_TX_STATUS_ARB_LOST;
+ arb_lost_cnt = cconr;
+ break;
+
+ case CDR2_CNF_NACK_ADDR:
+ tx_status = CEC_TX_STATUS_NACK;
+ nack_cnt = cconr;
+ break;
+
+ default: /* some other error, refer to TDA9950 docs */
+ dev_err(&priv->client->dev, "CNF reply error 0x%02x\n",
+ buf[2]);
+ tx_status = CEC_TX_STATUS_ERROR;
+ err_cnt = cconr;
+ break;
+ }
+ /* TDA9950 executes all retries for us */
+ tx_status |= CEC_TX_STATUS_MAX_RETRIES;
+ cec_transmit_done(priv->adap, tx_status, arb_lost_cnt,
+ nack_cnt, 0, err_cnt);
+ break;
+
+ case CDR1_IND:
+ priv->rx_msg.len = buf[0] - 2;
+ memcpy(priv->rx_msg.msg, buf + 2, priv->rx_msg.len);
+ cec_received_msg(priv->adap, &priv->rx_msg);
+ break;
+
+ default: /* unknown */
+ dev_err(&priv->client->dev, "unknown service id 0x%02x\n",
+ buf[1]);
+ break;
+ }
+
+ return IRQ_HANDLED;
+}
+
+static int tda9950_cec_transmit(struct cec_adapter *adap, u8 attempts,
+ u32 signal_free_time, struct cec_msg *msg)
+{
+ struct tda9950_priv *priv = adap->priv;
+ u8 buf[16 + 2];
+
+ buf[0] = 2 + msg->len;
+ buf[1] = CDR1_REQ;
+ memcpy(buf + 2, msg->msg, msg->len);
+
+ if (attempts > 5)
+ attempts = 5;
+
+ tda9950_write(priv->client, REG_CCONR, attempts);
+
+ return tda9950_write_range(priv->client, REG_CDR0, buf, 2 + msg->len);
+}
+
+static int tda9950_cec_adap_log_addr(struct cec_adapter *adap, u8 addr)
+{
+ struct tda9950_priv *priv = adap->priv;
+ u16 addresses;
+ u8 buf[2];
+
+ if (addr == CEC_LOG_ADDR_INVALID)
+ addresses = priv->addresses = 0;
+ else
+ addresses = priv->addresses |= BIT(addr);
+
+ /* TDA9950 doesn't want address 15 set */
+ addresses &= 0x7fff;
+ buf[0] = addresses >> 8;
+ buf[1] = addresses;
+
+ return tda9950_write_range(priv->client, REG_ACKH, buf, 2);
+}
+
+/*
+ * When operating as part of the TDA998x, we need additional handling
+ * to initialise and shut down the TDA9950 part of the device. These
+ * two hooks are provided to allow the TDA998x code to perform those
+ * activities.
+ */
+static int tda9950_glue_open(struct tda9950_priv *priv)
+{
+ int ret = 0;
+
+ if (priv->glue && priv->glue->open)
+ ret = priv->glue->open(priv->glue->data);
+
+ priv->open = true;
+
+ return ret;
+}
+
+static void tda9950_glue_release(struct tda9950_priv *priv)
+{
+ priv->open = false;
+
+ if (priv->glue && priv->glue->release)
+ priv->glue->release(priv->glue->data);
+}
+
+static int tda9950_open(struct tda9950_priv *priv)
+{
+ struct i2c_client *client = priv->client;
+ int ret;
+
+ ret = tda9950_glue_open(priv);
+ if (ret)
+ return ret;
+
+ /* Reset the TDA9950, and wait 250ms for it to recover */
+ tda9950_write(client, REG_CCR, CCR_RESET);
+ msleep(250);
+
+ tda9950_cec_adap_log_addr(priv->adap, CEC_LOG_ADDR_INVALID);
+
+ /* Start the command processor */
+ tda9950_write(client, REG_CCR, CCR_ON);
+
+ return 0;
+}
+
+static void tda9950_release(struct tda9950_priv *priv)
+{
+ struct i2c_client *client = priv->client;
+ int timeout = 50;
+ u8 csr;
+
+ /* Stop the command processor */
+ tda9950_write(client, REG_CCR, 0);
+
+ /* Wait up to .5s for it to signal non-busy */
+ do {
+ csr = tda9950_read(client, REG_CSR);
+ if (!(csr & CSR_BUSY) || --timeout)
+ break;
+ msleep(10);
+ } while (1);
+
+ /* Warn the user that their IRQ may die if it's shared. */
+ if (csr & CSR_BUSY)
+ dev_warn(&client->dev, "command processor failed to stop, irq%d may die (csr=0x%02x)\n",
+ client->irq, csr);
+
+ tda9950_glue_release(priv);
+}
+
+static int tda9950_cec_adap_enable(struct cec_adapter *adap, bool enable)
+{
+ struct tda9950_priv *priv = adap->priv;
+
+ if (!enable) {
+ tda9950_release(priv);
+ return 0;
+ } else {
+ return tda9950_open(priv);
+ }
+}
+
+static const struct cec_adap_ops tda9950_cec_ops = {
+ .adap_enable = tda9950_cec_adap_enable,
+ .adap_log_addr = tda9950_cec_adap_log_addr,
+ .adap_transmit = tda9950_cec_transmit,
+};
+
+/*
+ * When operating as part of the TDA998x, we need to claim additional
+ * resources. These two hooks permit the management of those resources.
+ */
+static void tda9950_devm_glue_exit(void *data)
+{
+ struct tda9950_glue *glue = data;
+
+ if (glue && glue->exit)
+ glue->exit(glue->data);
+}
+
+static int tda9950_devm_glue_init(struct device *dev, struct tda9950_glue *glue)
+{
+ int ret;
+
+ if (glue && glue->init) {
+ ret = glue->init(glue->data);
+ if (ret)
+ return ret;
+ }
+
+ ret = devm_add_action(dev, tda9950_devm_glue_exit, glue);
+ if (ret)
+ tda9950_devm_glue_exit(glue);
+
+ return ret;
+}
+
+static void tda9950_cec_del(void *data)
+{
+ struct tda9950_priv *priv = data;
+
+ cec_delete_adapter(priv->adap);
+}
+
+static int tda9950_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct tda9950_glue *glue = client->dev.platform_data;
+ struct device *dev = &client->dev;
+ struct tda9950_priv *priv;
+ unsigned long irqflags;
+ int ret;
+ u8 cvr;
+
+ /*
+ * We must have I2C functionality: our multi-byte accesses
+ * must be performed as a single contiguous transaction.
+ */
+ if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+ dev_err(&client->dev,
+ "adapter does not support I2C functionality\n");
+ return -ENXIO;
+ }
+
+ /* We must have an interrupt to be functional. */
+ if (client->irq <= 0) {
+ dev_err(&client->dev, "driver requires an interrupt\n");
+ return -ENXIO;
+ }
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->client = client;
+ priv->glue = glue;
+
+ i2c_set_clientdata(client, priv);
+
+ /*
+ * If we're part of a TDA998x, we want the class devices to be
+ * associated with the HDMI Tx so we have a tight relationship
+ * between the HDMI interface and the CEC interface.
+ */
+ priv->hdmi = dev;
+ if (glue && glue->parent)
+ priv->hdmi = glue->parent;
+
+ priv->adap = cec_allocate_adapter(&tda9950_cec_ops, priv, "tda9950",
+ CEC_CAP_LOG_ADDRS |
+ CEC_CAP_TRANSMIT | CEC_CAP_RC,
+ CEC_MAX_LOG_ADDRS);
+ if (IS_ERR(priv->adap))
+ return PTR_ERR(priv->adap);
+
+ ret = devm_add_action(dev, tda9950_cec_del, priv);
+ if (ret) {
+ cec_delete_adapter(priv->adap);
+ return ret;
+ }
+
+ ret = tda9950_devm_glue_init(dev, glue);
+ if (ret)
+ return ret;
+
+ ret = tda9950_glue_open(priv);
+ if (ret)
+ return ret;
+
+ cvr = tda9950_read(client, REG_CVR);
+
+ dev_info(&client->dev,
+ "TDA9950 CEC interface, hardware version %u.%u\n",
+ cvr >> 4, cvr & 15);
+
+ tda9950_glue_release(priv);
+
+ irqflags = IRQF_TRIGGER_FALLING;
+ if (glue)
+ irqflags = glue->irq_flags;
+
+ ret = devm_request_threaded_irq(dev, client->irq, NULL, tda9950_irq,
+ irqflags | IRQF_SHARED | IRQF_ONESHOT,
+ dev_name(&client->dev), priv);
+ if (ret < 0)
+ return ret;
+
+ priv->notify = cec_notifier_get(priv->hdmi);
+ if (!priv->notify)
+ return -ENOMEM;
+
+ ret = cec_register_adapter(priv->adap, priv->hdmi);
+ if (ret < 0) {
+ cec_notifier_put(priv->notify);
+ return ret;
+ }
+
+ /*
+ * CEC documentation says we must not call cec_delete_adapter
+ * after a successful call to cec_register_adapter().
+ */
+ devm_remove_action(dev, tda9950_cec_del, priv);
+
+ cec_register_cec_notifier(priv->adap, priv->notify);
+
+ return 0;
+}
+
+static int tda9950_remove(struct i2c_client *client)
+{
+ struct tda9950_priv *priv = i2c_get_clientdata(client);
+
+ cec_unregister_adapter(priv->adap);
+ cec_notifier_put(priv->notify);
+
+ return 0;
+}
+
+static struct i2c_device_id tda9950_ids[] = {
+ { "tda9950", 0 },
+ { },
+};
+MODULE_DEVICE_TABLE(i2c, tda9950_ids);
+
+static struct i2c_driver tda9950_driver = {
+ .probe = tda9950_probe,
+ .remove = tda9950_remove,
+ .driver = {
+ .name = "tda9950",
+ },
+ .id_table = tda9950_ids,
+};
+
+module_i2c_driver(tda9950_driver);
+
+MODULE_AUTHOR("Russell King <rmk+kernel@xxxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("TDA9950/TDA998x Consumer Electronics Control Driver");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/platform_data/tda9950.h b/include/linux/platform_data/tda9950.h
new file mode 100644
index 000000000000..c65efd461102
--- /dev/null
+++ b/include/linux/platform_data/tda9950.h
@@ -0,0 +1,16 @@
+#ifndef LINUX_PLATFORM_DATA_TDA9950_H
+#define LINUX_PLATFORM_DATA_TDA9950_H
+
+struct device;
+
+struct tda9950_glue {
+ struct device *parent;
+ unsigned long irq_flags;
+ void *data;
+ int (*init)(void *);
+ void (*exit)(void *);
+ int (*open)(void *);
+ void (*release)(void *);
+};
+
+#endif
--
2.7.4
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