// SPDX-License-Identifier: GPL-2.0-only /* * Copyright 2017 Cisco Systems, Inc. and/or its affiliates. All rights reserved. */ #include <linux/delay.h> #include <linux/slab.h> #include <linux/sched/types.h> #include <media/cec-pin.h> #include "cec-pin-priv.h" /* All timings are in microseconds */ /* start bit timings */ #define CEC_TIM_START_BIT_LOW … #define CEC_TIM_START_BIT_LOW_MIN … #define CEC_TIM_START_BIT_LOW_MAX … #define CEC_TIM_START_BIT_TOTAL … #define CEC_TIM_START_BIT_TOTAL_MIN … #define CEC_TIM_START_BIT_TOTAL_MAX … /* data bit timings */ #define CEC_TIM_DATA_BIT_0_LOW … #define CEC_TIM_DATA_BIT_0_LOW_MIN … #define CEC_TIM_DATA_BIT_0_LOW_MAX … #define CEC_TIM_DATA_BIT_1_LOW … #define CEC_TIM_DATA_BIT_1_LOW_MIN … #define CEC_TIM_DATA_BIT_1_LOW_MAX … #define CEC_TIM_DATA_BIT_TOTAL … #define CEC_TIM_DATA_BIT_TOTAL_MIN … #define CEC_TIM_DATA_BIT_TOTAL_MAX … /* earliest safe time to sample the bit state */ #define CEC_TIM_DATA_BIT_SAMPLE … /* earliest time the bit is back to 1 (T7 + 50) */ #define CEC_TIM_DATA_BIT_HIGH … /* when idle, sample once per millisecond */ #define CEC_TIM_IDLE_SAMPLE … /* when processing the start bit, sample twice per millisecond */ #define CEC_TIM_START_BIT_SAMPLE … /* when polling for a state change, sample once every 50 microseconds */ #define CEC_TIM_SAMPLE … #define CEC_TIM_LOW_DRIVE_ERROR … /* * Total data bit time that is too short/long for a valid bit, * used for error injection. */ #define CEC_TIM_DATA_BIT_TOTAL_SHORT … #define CEC_TIM_DATA_BIT_TOTAL_LONG … /* * Total start bit time that is too short/long for a valid bit, * used for error injection. */ #define CEC_TIM_START_BIT_TOTAL_SHORT … #define CEC_TIM_START_BIT_TOTAL_LONG … /* Data bits are 0-7, EOM is bit 8 and ACK is bit 9 */ #define EOM_BIT … #define ACK_BIT … struct cec_state { … }; static const struct cec_state states[CEC_PIN_STATES] = …; static void cec_pin_update(struct cec_pin *pin, bool v, bool force) { … } static bool cec_pin_read(struct cec_pin *pin) { … } static void cec_pin_low(struct cec_pin *pin) { … } static bool cec_pin_high(struct cec_pin *pin) { … } static bool rx_error_inj(struct cec_pin *pin, unsigned int mode_offset, int arg_idx, u8 *arg) { … } static bool rx_nack(struct cec_pin *pin) { … } static bool rx_low_drive(struct cec_pin *pin) { … } static bool rx_add_byte(struct cec_pin *pin) { … } static bool rx_remove_byte(struct cec_pin *pin) { … } static bool rx_arb_lost(struct cec_pin *pin, u8 *poll) { … } static bool tx_error_inj(struct cec_pin *pin, unsigned int mode_offset, int arg_idx, u8 *arg) { … } static bool tx_no_eom(struct cec_pin *pin) { … } static bool tx_early_eom(struct cec_pin *pin) { … } static bool tx_short_bit(struct cec_pin *pin) { … } static bool tx_long_bit(struct cec_pin *pin) { … } static bool tx_custom_bit(struct cec_pin *pin) { … } static bool tx_short_start(struct cec_pin *pin) { … } static bool tx_long_start(struct cec_pin *pin) { … } static bool tx_custom_start(struct cec_pin *pin) { … } static bool tx_last_bit(struct cec_pin *pin) { … } static u8 tx_add_bytes(struct cec_pin *pin) { … } static bool tx_remove_byte(struct cec_pin *pin) { … } static bool tx_low_drive(struct cec_pin *pin) { … } static void cec_pin_to_idle(struct cec_pin *pin) { … } /* * Handle Transmit-related states * * Basic state changes when transmitting: * * Idle -> Tx Wait (waiting for the end of signal free time) -> * Tx Start Bit Low -> Tx Start Bit High -> * * Regular data bits + EOM: * Tx Data 0 Low -> Tx Data 0 High -> * or: * Tx Data 1 Low -> Tx Data 1 High -> * * First 4 data bits or Ack bit: * Tx Data 0 Low -> Tx Data 0 High -> * or: * Tx Data 1 Low -> Tx Data 1 High -> Tx Data 1 Pre Sample -> * Tx Data 1 Post Sample -> * * After the last Ack go to Idle. * * If it detects a Low Drive condition then: * Tx Wait For High -> Idle * * If it loses arbitration, then it switches to state Rx Data Post Sample. */ static void cec_pin_tx_states(struct cec_pin *pin, ktime_t ts) { … } /* * Handle Receive-related states * * Basic state changes when receiving: * * Rx Start Bit Low -> Rx Start Bit High -> * Regular data bits + EOM: * Rx Data Sample -> Rx Data Post Sample -> Rx Data High -> * Ack bit 0: * Rx Ack Low -> Rx Ack Low Post -> Rx Data High -> * Ack bit 1: * Rx Ack High Post -> Rx Data High -> * Ack bit 0 && EOM: * Rx Ack Low -> Rx Ack Low Post -> Rx Ack Finish -> Idle */ static void cec_pin_rx_states(struct cec_pin *pin, ktime_t ts) { … } /* * Main timer function * */ static enum hrtimer_restart cec_pin_timer(struct hrtimer *timer) { … } static int cec_pin_thread_func(void *_adap) { … } static int cec_pin_adap_enable(struct cec_adapter *adap, bool enable) { … } static int cec_pin_adap_log_addr(struct cec_adapter *adap, u8 log_addr) { … } void cec_pin_start_timer(struct cec_pin *pin) { … } static int cec_pin_adap_transmit(struct cec_adapter *adap, u8 attempts, u32 signal_free_time, struct cec_msg *msg) { … } static void cec_pin_adap_status(struct cec_adapter *adap, struct seq_file *file) { … } static int cec_pin_adap_monitor_all_enable(struct cec_adapter *adap, bool enable) { … } static void cec_pin_adap_free(struct cec_adapter *adap) { … } static int cec_pin_received(struct cec_adapter *adap, struct cec_msg *msg) { … } void cec_pin_changed(struct cec_adapter *adap, bool value) { … } EXPORT_SYMBOL_GPL(…); static const struct cec_adap_ops cec_pin_adap_ops = …; struct cec_adapter *cec_pin_allocate_adapter(const struct cec_pin_ops *pin_ops, void *priv, const char *name, u32 caps) { … } EXPORT_SYMBOL_GPL(…);
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