drm/i2c: tda9950: add CEC driver
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. Reviewed-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
This commit is contained in:
Russell King
parent
ba8975f15b
commit
f0316f9389
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@ -26,4 +26,9 @@ config DRM_I2C_NXP_TDA998X
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help
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Support for NXP Semiconductors TDA998X HDMI encoders.
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config DRM_I2C_NXP_TDA9950
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tristate "NXP Semiconductors TDA9950/TDA998X HDMI CEC"
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select CEC_NOTIFIER
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select CEC_CORE
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endmenu
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@ -7,3 +7,4 @@ obj-$(CONFIG_DRM_I2C_SIL164) += sil164.o
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tda998x-y := tda998x_drv.o
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obj-$(CONFIG_DRM_I2C_NXP_TDA998X) += tda998x.o
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obj-$(CONFIG_DRM_I2C_NXP_TDA9950) += tda9950.o
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@ -0,0 +1,509 @@
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/*
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* TDA9950 Consumer Electronics Control driver
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* The NXP TDA9950 implements the HDMI Consumer Electronics Control
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* interface. The host interface is similar to a mailbox: the data
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* registers starting at REG_CDR0 are written to send a command to the
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* internal CPU, and replies are read from these registers.
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*
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* As the data registers represent a mailbox, they must be accessed
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* as a single I2C transaction. See the TDA9950 data sheet for details.
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*/
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#include <linux/delay.h>
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#include <linux/i2c.h>
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#include <linux/interrupt.h>
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#include <linux/module.h>
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#include <linux/platform_data/tda9950.h>
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#include <linux/slab.h>
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#include <drm/drm_edid.h>
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#include <media/cec.h>
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#include <media/cec-notifier.h>
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enum {
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REG_CSR = 0x00,
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CSR_BUSY = BIT(7),
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CSR_INT = BIT(6),
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CSR_ERR = BIT(5),
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REG_CER = 0x01,
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REG_CVR = 0x02,
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REG_CCR = 0x03,
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CCR_RESET = BIT(7),
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CCR_ON = BIT(6),
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REG_ACKH = 0x04,
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REG_ACKL = 0x05,
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REG_CCONR = 0x06,
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CCONR_ENABLE_ERROR = BIT(4),
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CCONR_RETRY_MASK = 7,
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REG_CDR0 = 0x07,
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CDR1_REQ = 0x00,
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CDR1_CNF = 0x01,
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CDR1_IND = 0x81,
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CDR1_ERR = 0x82,
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CDR1_IER = 0x83,
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CDR2_CNF_SUCCESS = 0x00,
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CDR2_CNF_OFF_STATE = 0x80,
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CDR2_CNF_BAD_REQ = 0x81,
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CDR2_CNF_CEC_ACCESS = 0x82,
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CDR2_CNF_ARB_ERROR = 0x83,
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CDR2_CNF_BAD_TIMING = 0x84,
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CDR2_CNF_NACK_ADDR = 0x85,
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CDR2_CNF_NACK_DATA = 0x86,
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};
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struct tda9950_priv {
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struct i2c_client *client;
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struct device *hdmi;
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struct cec_adapter *adap;
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struct tda9950_glue *glue;
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u16 addresses;
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struct cec_msg rx_msg;
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struct cec_notifier *notify;
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bool open;
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};
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static int tda9950_write_range(struct i2c_client *client, u8 addr, u8 *p, int cnt)
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{
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struct i2c_msg msg;
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u8 buf[cnt + 1];
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int ret;
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buf[0] = addr;
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memcpy(buf + 1, p, cnt);
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msg.addr = client->addr;
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msg.flags = 0;
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msg.len = cnt + 1;
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msg.buf = buf;
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dev_dbg(&client->dev, "wr 0x%02x: %*ph\n", addr, cnt, p);
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ret = i2c_transfer(client->adapter, &msg, 1);
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if (ret < 0)
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dev_err(&client->dev, "Error %d writing to cec:0x%x\n", ret, addr);
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return ret < 0 ? ret : 0;
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}
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static void tda9950_write(struct i2c_client *client, u8 addr, u8 val)
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{
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tda9950_write_range(client, addr, &val, 1);
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}
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static int tda9950_read_range(struct i2c_client *client, u8 addr, u8 *p, int cnt)
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{
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struct i2c_msg msg[2];
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int ret;
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msg[0].addr = client->addr;
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msg[0].flags = 0;
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msg[0].len = 1;
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msg[0].buf = &addr;
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msg[1].addr = client->addr;
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msg[1].flags = I2C_M_RD;
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msg[1].len = cnt;
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msg[1].buf = p;
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ret = i2c_transfer(client->adapter, msg, 2);
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if (ret < 0)
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dev_err(&client->dev, "Error %d reading from cec:0x%x\n", ret, addr);
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dev_dbg(&client->dev, "rd 0x%02x: %*ph\n", addr, cnt, p);
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return ret;
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}
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static u8 tda9950_read(struct i2c_client *client, u8 addr)
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{
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int ret;
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u8 val;
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ret = tda9950_read_range(client, addr, &val, 1);
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if (ret < 0)
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val = 0;
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return val;
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}
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static irqreturn_t tda9950_irq(int irq, void *data)
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{
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struct tda9950_priv *priv = data;
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unsigned int tx_status;
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u8 csr, cconr, buf[19];
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u8 arb_lost_cnt, nack_cnt, err_cnt;
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if (!priv->open)
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return IRQ_NONE;
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csr = tda9950_read(priv->client, REG_CSR);
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if (!(csr & CSR_INT))
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return IRQ_NONE;
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cconr = tda9950_read(priv->client, REG_CCONR) & CCONR_RETRY_MASK;
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tda9950_read_range(priv->client, REG_CDR0, buf, sizeof(buf));
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/*
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* This should never happen: the data sheet says that there will
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* always be a valid message if the interrupt line is asserted.
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*/
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if (buf[0] == 0) {
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dev_warn(&priv->client->dev, "interrupt pending, but no message?\n");
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return IRQ_NONE;
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}
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switch (buf[1]) {
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case CDR1_CNF: /* transmit result */
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arb_lost_cnt = nack_cnt = err_cnt = 0;
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switch (buf[2]) {
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case CDR2_CNF_SUCCESS:
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tx_status = CEC_TX_STATUS_OK;
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break;
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case CDR2_CNF_ARB_ERROR:
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tx_status = CEC_TX_STATUS_ARB_LOST;
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arb_lost_cnt = cconr;
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break;
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case CDR2_CNF_NACK_ADDR:
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tx_status = CEC_TX_STATUS_NACK;
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nack_cnt = cconr;
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break;
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default: /* some other error, refer to TDA9950 docs */
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dev_err(&priv->client->dev, "CNF reply error 0x%02x\n",
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buf[2]);
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tx_status = CEC_TX_STATUS_ERROR;
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err_cnt = cconr;
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break;
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}
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/* TDA9950 executes all retries for us */
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tx_status |= CEC_TX_STATUS_MAX_RETRIES;
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cec_transmit_done(priv->adap, tx_status, arb_lost_cnt,
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nack_cnt, 0, err_cnt);
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break;
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case CDR1_IND:
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priv->rx_msg.len = buf[0] - 2;
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if (priv->rx_msg.len > CEC_MAX_MSG_SIZE)
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priv->rx_msg.len = CEC_MAX_MSG_SIZE;
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memcpy(priv->rx_msg.msg, buf + 2, priv->rx_msg.len);
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cec_received_msg(priv->adap, &priv->rx_msg);
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break;
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default: /* unknown */
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dev_err(&priv->client->dev, "unknown service id 0x%02x\n",
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buf[1]);
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break;
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}
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return IRQ_HANDLED;
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}
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static int tda9950_cec_transmit(struct cec_adapter *adap, u8 attempts,
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u32 signal_free_time, struct cec_msg *msg)
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{
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struct tda9950_priv *priv = adap->priv;
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u8 buf[CEC_MAX_MSG_SIZE + 2];
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buf[0] = 2 + msg->len;
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buf[1] = CDR1_REQ;
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memcpy(buf + 2, msg->msg, msg->len);
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if (attempts > 5)
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attempts = 5;
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tda9950_write(priv->client, REG_CCONR, attempts);
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return tda9950_write_range(priv->client, REG_CDR0, buf, 2 + msg->len);
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}
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static int tda9950_cec_adap_log_addr(struct cec_adapter *adap, u8 addr)
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{
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struct tda9950_priv *priv = adap->priv;
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u16 addresses;
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u8 buf[2];
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if (addr == CEC_LOG_ADDR_INVALID)
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addresses = priv->addresses = 0;
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else
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addresses = priv->addresses |= BIT(addr);
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/* TDA9950 doesn't want address 15 set */
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addresses &= 0x7fff;
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buf[0] = addresses >> 8;
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buf[1] = addresses;
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return tda9950_write_range(priv->client, REG_ACKH, buf, 2);
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}
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/*
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* When operating as part of the TDA998x, we need additional handling
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* to initialise and shut down the TDA9950 part of the device. These
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* two hooks are provided to allow the TDA998x code to perform those
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* activities.
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*/
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static int tda9950_glue_open(struct tda9950_priv *priv)
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{
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int ret = 0;
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if (priv->glue && priv->glue->open)
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ret = priv->glue->open(priv->glue->data);
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priv->open = true;
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return ret;
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}
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static void tda9950_glue_release(struct tda9950_priv *priv)
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{
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priv->open = false;
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if (priv->glue && priv->glue->release)
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priv->glue->release(priv->glue->data);
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}
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static int tda9950_open(struct tda9950_priv *priv)
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{
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struct i2c_client *client = priv->client;
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int ret;
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ret = tda9950_glue_open(priv);
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if (ret)
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return ret;
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/* Reset the TDA9950, and wait 250ms for it to recover */
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tda9950_write(client, REG_CCR, CCR_RESET);
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msleep(250);
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tda9950_cec_adap_log_addr(priv->adap, CEC_LOG_ADDR_INVALID);
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/* Start the command processor */
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tda9950_write(client, REG_CCR, CCR_ON);
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return 0;
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}
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static void tda9950_release(struct tda9950_priv *priv)
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{
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struct i2c_client *client = priv->client;
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int timeout = 50;
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u8 csr;
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/* Stop the command processor */
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tda9950_write(client, REG_CCR, 0);
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/* Wait up to .5s for it to signal non-busy */
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do {
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csr = tda9950_read(client, REG_CSR);
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if (!(csr & CSR_BUSY) || --timeout)
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break;
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msleep(10);
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} while (1);
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/* Warn the user that their IRQ may die if it's shared. */
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if (csr & CSR_BUSY)
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dev_warn(&client->dev, "command processor failed to stop, irq%d may die (csr=0x%02x)\n",
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client->irq, csr);
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tda9950_glue_release(priv);
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}
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static int tda9950_cec_adap_enable(struct cec_adapter *adap, bool enable)
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{
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struct tda9950_priv *priv = adap->priv;
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if (!enable) {
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tda9950_release(priv);
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return 0;
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} else {
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return tda9950_open(priv);
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}
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}
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static const struct cec_adap_ops tda9950_cec_ops = {
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.adap_enable = tda9950_cec_adap_enable,
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.adap_log_addr = tda9950_cec_adap_log_addr,
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.adap_transmit = tda9950_cec_transmit,
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};
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/*
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* When operating as part of the TDA998x, we need to claim additional
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* resources. These two hooks permit the management of those resources.
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*/
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static void tda9950_devm_glue_exit(void *data)
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{
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struct tda9950_glue *glue = data;
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if (glue && glue->exit)
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glue->exit(glue->data);
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}
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static int tda9950_devm_glue_init(struct device *dev, struct tda9950_glue *glue)
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{
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int ret;
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if (glue && glue->init) {
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ret = glue->init(glue->data);
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if (ret)
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return ret;
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}
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ret = devm_add_action(dev, tda9950_devm_glue_exit, glue);
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if (ret)
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tda9950_devm_glue_exit(glue);
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return ret;
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}
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static void tda9950_cec_del(void *data)
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{
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struct tda9950_priv *priv = data;
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cec_delete_adapter(priv->adap);
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}
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static int tda9950_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct tda9950_glue *glue = client->dev.platform_data;
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struct device *dev = &client->dev;
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struct tda9950_priv *priv;
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unsigned long irqflags;
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int ret;
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u8 cvr;
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/*
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* We must have I2C functionality: our multi-byte accesses
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* must be performed as a single contiguous transaction.
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*/
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if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
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dev_err(&client->dev,
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"adapter does not support I2C functionality\n");
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return -ENXIO;
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}
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/* We must have an interrupt to be functional. */
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if (client->irq <= 0) {
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dev_err(&client->dev, "driver requires an interrupt\n");
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return -ENXIO;
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}
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priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
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if (!priv)
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return -ENOMEM;
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priv->client = client;
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priv->glue = glue;
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i2c_set_clientdata(client, priv);
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/*
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* If we're part of a TDA998x, we want the class devices to be
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* associated with the HDMI Tx so we have a tight relationship
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* between the HDMI interface and the CEC interface.
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*/
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priv->hdmi = dev;
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if (glue && glue->parent)
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priv->hdmi = glue->parent;
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priv->adap = cec_allocate_adapter(&tda9950_cec_ops, priv, "tda9950",
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CEC_CAP_DEFAULTS,
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CEC_MAX_LOG_ADDRS);
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if (IS_ERR(priv->adap))
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return PTR_ERR(priv->adap);
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ret = devm_add_action(dev, tda9950_cec_del, priv);
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if (ret) {
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cec_delete_adapter(priv->adap);
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return ret;
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}
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ret = tda9950_devm_glue_init(dev, glue);
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if (ret)
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return ret;
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ret = tda9950_glue_open(priv);
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if (ret)
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return ret;
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cvr = tda9950_read(client, REG_CVR);
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dev_info(&client->dev,
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"TDA9950 CEC interface, hardware version %u.%u\n",
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cvr >> 4, cvr & 15);
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tda9950_glue_release(priv);
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irqflags = IRQF_TRIGGER_FALLING;
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if (glue)
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irqflags = glue->irq_flags;
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ret = devm_request_threaded_irq(dev, client->irq, NULL, tda9950_irq,
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irqflags | IRQF_SHARED | IRQF_ONESHOT,
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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");
|
||||
|
|
@ -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
|
||||
Loading…
Reference in New Issue