diff options
Diffstat (limited to 'drivers/gpu/drm/bridge/adv7511/adv7511_cec.c')
| -rw-r--r-- | drivers/gpu/drm/bridge/adv7511/adv7511_cec.c | 392 |
1 files changed, 392 insertions, 0 deletions
diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_cec.c b/drivers/gpu/drm/bridge/adv7511/adv7511_cec.c new file mode 100644 index 000000000..99964f5a5 --- /dev/null +++ b/drivers/gpu/drm/bridge/adv7511/adv7511_cec.c @@ -0,0 +1,392 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * adv7511_cec.c - Analog Devices ADV7511/33 cec driver + * + * Copyright 2017 Cisco Systems, Inc. and/or its affiliates. All rights reserved. + */ + +#include <linux/device.h> +#include <linux/module.h> +#include <linux/of_device.h> +#include <linux/slab.h> +#include <linux/clk.h> + +#include <media/cec.h> + +#include "adv7511.h" + +static const u8 ADV7511_REG_CEC_RX_FRAME_HDR[] = { + ADV7511_REG_CEC_RX1_FRAME_HDR, + ADV7511_REG_CEC_RX2_FRAME_HDR, + ADV7511_REG_CEC_RX3_FRAME_HDR, +}; + +static const u8 ADV7511_REG_CEC_RX_FRAME_LEN[] = { + ADV7511_REG_CEC_RX1_FRAME_LEN, + ADV7511_REG_CEC_RX2_FRAME_LEN, + ADV7511_REG_CEC_RX3_FRAME_LEN, +}; + +#define ADV7511_INT1_CEC_MASK \ + (ADV7511_INT1_CEC_TX_READY | ADV7511_INT1_CEC_TX_ARBIT_LOST | \ + ADV7511_INT1_CEC_TX_RETRY_TIMEOUT | ADV7511_INT1_CEC_RX_READY1 | \ + ADV7511_INT1_CEC_RX_READY2 | ADV7511_INT1_CEC_RX_READY3) + +static void adv_cec_tx_raw_status(struct adv7511 *adv7511, u8 tx_raw_status) +{ + unsigned int offset = adv7511->reg_cec_offset; + unsigned int val; + + if (regmap_read(adv7511->regmap_cec, + ADV7511_REG_CEC_TX_ENABLE + offset, &val)) + return; + + if ((val & 0x01) == 0) + return; + + if (tx_raw_status & ADV7511_INT1_CEC_TX_ARBIT_LOST) { + cec_transmit_attempt_done(adv7511->cec_adap, + CEC_TX_STATUS_ARB_LOST); + return; + } + if (tx_raw_status & ADV7511_INT1_CEC_TX_RETRY_TIMEOUT) { + u8 status; + u8 err_cnt = 0; + u8 nack_cnt = 0; + u8 low_drive_cnt = 0; + unsigned int cnt; + + /* + * We set this status bit since this hardware performs + * retransmissions. + */ + status = CEC_TX_STATUS_MAX_RETRIES; + if (regmap_read(adv7511->regmap_cec, + ADV7511_REG_CEC_TX_LOW_DRV_CNT + offset, &cnt)) { + err_cnt = 1; + status |= CEC_TX_STATUS_ERROR; + } else { + nack_cnt = cnt & 0xf; + if (nack_cnt) + status |= CEC_TX_STATUS_NACK; + low_drive_cnt = cnt >> 4; + if (low_drive_cnt) + status |= CEC_TX_STATUS_LOW_DRIVE; + } + cec_transmit_done(adv7511->cec_adap, status, + 0, nack_cnt, low_drive_cnt, err_cnt); + return; + } + if (tx_raw_status & ADV7511_INT1_CEC_TX_READY) { + cec_transmit_attempt_done(adv7511->cec_adap, CEC_TX_STATUS_OK); + return; + } +} + +static void adv7511_cec_rx(struct adv7511 *adv7511, int rx_buf) +{ + unsigned int offset = adv7511->reg_cec_offset; + struct cec_msg msg = {}; + unsigned int len; + unsigned int val; + u8 i; + + if (regmap_read(adv7511->regmap_cec, + ADV7511_REG_CEC_RX_FRAME_LEN[rx_buf] + offset, &len)) + return; + + msg.len = len & 0x1f; + + if (msg.len > 16) + msg.len = 16; + + if (!msg.len) + return; + + for (i = 0; i < msg.len; i++) { + regmap_read(adv7511->regmap_cec, + i + ADV7511_REG_CEC_RX_FRAME_HDR[rx_buf] + offset, + &val); + msg.msg[i] = val; + } + + /* Toggle RX Ready Clear bit to re-enable this RX buffer */ + regmap_update_bits(adv7511->regmap_cec, + ADV7511_REG_CEC_RX_BUFFERS + offset, BIT(rx_buf), + BIT(rx_buf)); + regmap_update_bits(adv7511->regmap_cec, + ADV7511_REG_CEC_RX_BUFFERS + offset, BIT(rx_buf), 0); + + cec_received_msg(adv7511->cec_adap, &msg); +} + +void adv7511_cec_irq_process(struct adv7511 *adv7511, unsigned int irq1) +{ + unsigned int offset = adv7511->reg_cec_offset; + const u32 irq_tx_mask = ADV7511_INT1_CEC_TX_READY | + ADV7511_INT1_CEC_TX_ARBIT_LOST | + ADV7511_INT1_CEC_TX_RETRY_TIMEOUT; + const u32 irq_rx_mask = ADV7511_INT1_CEC_RX_READY1 | + ADV7511_INT1_CEC_RX_READY2 | + ADV7511_INT1_CEC_RX_READY3; + unsigned int rx_status; + int rx_order[3] = { -1, -1, -1 }; + int i; + + if (irq1 & irq_tx_mask) + adv_cec_tx_raw_status(adv7511, irq1); + + if (!(irq1 & irq_rx_mask)) + return; + + if (regmap_read(adv7511->regmap_cec, + ADV7511_REG_CEC_RX_STATUS + offset, &rx_status)) + return; + + /* + * ADV7511_REG_CEC_RX_STATUS[5:0] contains the reception order of RX + * buffers 0, 1, and 2 in bits [1:0], [3:2], and [5:4] respectively. + * The values are to be interpreted as follows: + * + * 0 = buffer unused + * 1 = buffer contains oldest received frame (if applicable) + * 2 = buffer contains second oldest received frame (if applicable) + * 3 = buffer contains third oldest received frame (if applicable) + * + * Fill rx_order with the sequence of RX buffer indices to + * read from in order, where -1 indicates that there are no + * more buffers to process. + */ + for (i = 0; i < 3; i++) { + unsigned int timestamp = (rx_status >> (2 * i)) & 0x3; + + if (timestamp) + rx_order[timestamp - 1] = i; + } + + /* Read CEC RX buffers in the appropriate order as prescribed above */ + for (i = 0; i < 3; i++) { + int rx_buf = rx_order[i]; + + if (rx_buf < 0) + break; + + adv7511_cec_rx(adv7511, rx_buf); + } +} + +static int adv7511_cec_adap_enable(struct cec_adapter *adap, bool enable) +{ + struct adv7511 *adv7511 = cec_get_drvdata(adap); + unsigned int offset = adv7511->reg_cec_offset; + + if (adv7511->i2c_cec == NULL) + return -EIO; + + if (!adv7511->cec_enabled_adap && enable) { + /* power up cec section */ + regmap_update_bits(adv7511->regmap_cec, + ADV7511_REG_CEC_CLK_DIV + offset, + 0x03, 0x01); + /* non-legacy mode and clear all rx buffers */ + regmap_write(adv7511->regmap_cec, + ADV7511_REG_CEC_RX_BUFFERS + offset, 0x0f); + regmap_write(adv7511->regmap_cec, + ADV7511_REG_CEC_RX_BUFFERS + offset, 0x08); + /* initially disable tx */ + regmap_update_bits(adv7511->regmap_cec, + ADV7511_REG_CEC_TX_ENABLE + offset, 1, 0); + /* enabled irqs: */ + /* tx: ready */ + /* tx: arbitration lost */ + /* tx: retry timeout */ + /* rx: ready 1-3 */ + regmap_update_bits(adv7511->regmap, + ADV7511_REG_INT_ENABLE(1), 0x3f, + ADV7511_INT1_CEC_MASK); + } else if (adv7511->cec_enabled_adap && !enable) { + regmap_update_bits(adv7511->regmap, + ADV7511_REG_INT_ENABLE(1), 0x3f, 0); + /* disable address mask 1-3 */ + regmap_update_bits(adv7511->regmap_cec, + ADV7511_REG_CEC_LOG_ADDR_MASK + offset, + 0x70, 0x00); + /* power down cec section */ + regmap_update_bits(adv7511->regmap_cec, + ADV7511_REG_CEC_CLK_DIV + offset, + 0x03, 0x00); + adv7511->cec_valid_addrs = 0; + } + adv7511->cec_enabled_adap = enable; + return 0; +} + +static int adv7511_cec_adap_log_addr(struct cec_adapter *adap, u8 addr) +{ + struct adv7511 *adv7511 = cec_get_drvdata(adap); + unsigned int offset = adv7511->reg_cec_offset; + unsigned int i, free_idx = ADV7511_MAX_ADDRS; + + if (!adv7511->cec_enabled_adap) + return addr == CEC_LOG_ADDR_INVALID ? 0 : -EIO; + + if (addr == CEC_LOG_ADDR_INVALID) { + regmap_update_bits(adv7511->regmap_cec, + ADV7511_REG_CEC_LOG_ADDR_MASK + offset, + 0x70, 0); + adv7511->cec_valid_addrs = 0; + return 0; + } + + for (i = 0; i < ADV7511_MAX_ADDRS; i++) { + bool is_valid = adv7511->cec_valid_addrs & (1 << i); + + if (free_idx == ADV7511_MAX_ADDRS && !is_valid) + free_idx = i; + if (is_valid && adv7511->cec_addr[i] == addr) + return 0; + } + if (i == ADV7511_MAX_ADDRS) { + i = free_idx; + if (i == ADV7511_MAX_ADDRS) + return -ENXIO; + } + adv7511->cec_addr[i] = addr; + adv7511->cec_valid_addrs |= 1 << i; + + switch (i) { + case 0: + /* enable address mask 0 */ + regmap_update_bits(adv7511->regmap_cec, + ADV7511_REG_CEC_LOG_ADDR_MASK + offset, + 0x10, 0x10); + /* set address for mask 0 */ + regmap_update_bits(adv7511->regmap_cec, + ADV7511_REG_CEC_LOG_ADDR_0_1 + offset, + 0x0f, addr); + break; + case 1: + /* enable address mask 1 */ + regmap_update_bits(adv7511->regmap_cec, + ADV7511_REG_CEC_LOG_ADDR_MASK + offset, + 0x20, 0x20); + /* set address for mask 1 */ + regmap_update_bits(adv7511->regmap_cec, + ADV7511_REG_CEC_LOG_ADDR_0_1 + offset, + 0xf0, addr << 4); + break; + case 2: + /* enable address mask 2 */ + regmap_update_bits(adv7511->regmap_cec, + ADV7511_REG_CEC_LOG_ADDR_MASK + offset, + 0x40, 0x40); + /* set address for mask 1 */ + regmap_update_bits(adv7511->regmap_cec, + ADV7511_REG_CEC_LOG_ADDR_2 + offset, + 0x0f, addr); + break; + } + return 0; +} + +static int adv7511_cec_adap_transmit(struct cec_adapter *adap, u8 attempts, + u32 signal_free_time, struct cec_msg *msg) +{ + struct adv7511 *adv7511 = cec_get_drvdata(adap); + unsigned int offset = adv7511->reg_cec_offset; + u8 len = msg->len; + unsigned int i; + + /* + * The number of retries is the number of attempts - 1, but retry + * at least once. It's not clear if a value of 0 is allowed, so + * let's do at least one retry. + */ + regmap_update_bits(adv7511->regmap_cec, + ADV7511_REG_CEC_TX_RETRY + offset, + 0x70, max(1, attempts - 1) << 4); + + /* blocking, clear cec tx irq status */ + regmap_update_bits(adv7511->regmap, ADV7511_REG_INT(1), 0x38, 0x38); + + /* write data */ + for (i = 0; i < len; i++) + regmap_write(adv7511->regmap_cec, + i + ADV7511_REG_CEC_TX_FRAME_HDR + offset, + msg->msg[i]); + + /* set length (data + header) */ + regmap_write(adv7511->regmap_cec, + ADV7511_REG_CEC_TX_FRAME_LEN + offset, len); + /* start transmit, enable tx */ + regmap_write(adv7511->regmap_cec, + ADV7511_REG_CEC_TX_ENABLE + offset, 0x01); + return 0; +} + +static const struct cec_adap_ops adv7511_cec_adap_ops = { + .adap_enable = adv7511_cec_adap_enable, + .adap_log_addr = adv7511_cec_adap_log_addr, + .adap_transmit = adv7511_cec_adap_transmit, +}; + +static int adv7511_cec_parse_dt(struct device *dev, struct adv7511 *adv7511) +{ + adv7511->cec_clk = devm_clk_get(dev, "cec"); + if (IS_ERR(adv7511->cec_clk)) { + int ret = PTR_ERR(adv7511->cec_clk); + + adv7511->cec_clk = NULL; + return ret; + } + clk_prepare_enable(adv7511->cec_clk); + adv7511->cec_clk_freq = clk_get_rate(adv7511->cec_clk); + return 0; +} + +int adv7511_cec_init(struct device *dev, struct adv7511 *adv7511) +{ + unsigned int offset = adv7511->reg_cec_offset; + int ret = adv7511_cec_parse_dt(dev, adv7511); + + if (ret) + goto err_cec_parse_dt; + + adv7511->cec_adap = cec_allocate_adapter(&adv7511_cec_adap_ops, + adv7511, dev_name(dev), CEC_CAP_DEFAULTS, ADV7511_MAX_ADDRS); + if (IS_ERR(adv7511->cec_adap)) { + ret = PTR_ERR(adv7511->cec_adap); + goto err_cec_alloc; + } + + regmap_write(adv7511->regmap, ADV7511_REG_CEC_CTRL, 0); + /* cec soft reset */ + regmap_write(adv7511->regmap_cec, + ADV7511_REG_CEC_SOFT_RESET + offset, 0x01); + regmap_write(adv7511->regmap_cec, + ADV7511_REG_CEC_SOFT_RESET + offset, 0x00); + + /* non-legacy mode - use all three RX buffers */ + regmap_write(adv7511->regmap_cec, + ADV7511_REG_CEC_RX_BUFFERS + offset, 0x08); + + regmap_write(adv7511->regmap_cec, + ADV7511_REG_CEC_CLK_DIV + offset, + ((adv7511->cec_clk_freq / 750000) - 1) << 2); + + ret = cec_register_adapter(adv7511->cec_adap, dev); + if (ret) + goto err_cec_register; + return 0; + +err_cec_register: + cec_delete_adapter(adv7511->cec_adap); + adv7511->cec_adap = NULL; +err_cec_alloc: + dev_info(dev, "Initializing CEC failed with error %d, disabling CEC\n", + ret); +err_cec_parse_dt: + regmap_write(adv7511->regmap, ADV7511_REG_CEC_CTRL, + ADV7511_CEC_CTRL_POWER_DOWN); + return ret == -EPROBE_DEFER ? ret : 0; +} |