| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * TDA9950 Consumer Electronics Control driver |
| * |
| * 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[CEC_MAX_MSG_SIZE + 3]; |
| int ret; |
| |
| if (WARN_ON(cnt > sizeof(buf) - 1)) |
| return -EINVAL; |
| |
| 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 */ |
| if (tx_status != CEC_TX_STATUS_OK) |
| 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; |
| if (priv->rx_msg.len > CEC_MAX_MSG_SIZE) |
| priv->rx_msg.len = CEC_MAX_MSG_SIZE; |
| |
| 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[CEC_MAX_MSG_SIZE + 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_DEFAULTS, |
| 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@armlinux.org.uk>"); |
| MODULE_DESCRIPTION("TDA9950/TDA998x Consumer Electronics Control Driver"); |
| MODULE_LICENSE("GPL v2"); |