diff options
Diffstat (limited to 'drivers/gpu/drm/i2c/tda9950.c')
| -rw-r--r-- | drivers/gpu/drm/i2c/tda9950.c | 510 |
1 files changed, 510 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i2c/tda9950.c b/drivers/gpu/drm/i2c/tda9950.c new file mode 100644 index 000000000..5b03fdd1e --- /dev/null +++ b/drivers/gpu/drm/i2c/tda9950.c @@ -0,0 +1,510 @@ +// 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_CAP_CONNECTOR_INFO, + 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_cec_adap_register(priv->hdmi, NULL, + priv->adap); + if (!priv->notify) + return -ENOMEM; + + ret = cec_register_adapter(priv->adap, priv->hdmi); + if (ret < 0) { + cec_notifier_cec_adap_unregister(priv->notify, priv->adap); + 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); + + return 0; +} + +static int tda9950_remove(struct i2c_client *client) +{ + struct tda9950_priv *priv = i2c_get_clientdata(client); + + cec_notifier_cec_adap_unregister(priv->notify, priv->adap); + cec_unregister_adapter(priv->adap); + + 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"); |