summaryrefslogtreecommitdiffstats
path: root/drivers/media/cec/core/cec-pin.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/media/cec/core/cec-pin.c')
-rw-r--r--drivers/media/cec/core/cec-pin.c1357
1 files changed, 1357 insertions, 0 deletions
diff --git a/drivers/media/cec/core/cec-pin.c b/drivers/media/cec/core/cec-pin.c
new file mode 100644
index 000000000..68353c5dc
--- /dev/null
+++ b/drivers/media/cec/core/cec-pin.c
@@ -0,0 +1,1357 @@
+// 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 3700
+#define CEC_TIM_START_BIT_LOW_MIN 3500
+#define CEC_TIM_START_BIT_LOW_MAX 3900
+#define CEC_TIM_START_BIT_TOTAL 4500
+#define CEC_TIM_START_BIT_TOTAL_MIN 4300
+#define CEC_TIM_START_BIT_TOTAL_MAX 4700
+
+/* data bit timings */
+#define CEC_TIM_DATA_BIT_0_LOW 1500
+#define CEC_TIM_DATA_BIT_0_LOW_MIN 1300
+#define CEC_TIM_DATA_BIT_0_LOW_MAX 1700
+#define CEC_TIM_DATA_BIT_1_LOW 600
+#define CEC_TIM_DATA_BIT_1_LOW_MIN 400
+#define CEC_TIM_DATA_BIT_1_LOW_MAX 800
+#define CEC_TIM_DATA_BIT_TOTAL 2400
+#define CEC_TIM_DATA_BIT_TOTAL_MIN 2050
+#define CEC_TIM_DATA_BIT_TOTAL_MAX 2750
+/* earliest safe time to sample the bit state */
+#define CEC_TIM_DATA_BIT_SAMPLE 850
+/* earliest time the bit is back to 1 (T7 + 50) */
+#define CEC_TIM_DATA_BIT_HIGH 1750
+
+/* when idle, sample once per millisecond */
+#define CEC_TIM_IDLE_SAMPLE 1000
+/* when processing the start bit, sample twice per millisecond */
+#define CEC_TIM_START_BIT_SAMPLE 500
+/* when polling for a state change, sample once every 50 microseconds */
+#define CEC_TIM_SAMPLE 50
+
+#define CEC_TIM_LOW_DRIVE_ERROR (1.5 * CEC_TIM_DATA_BIT_TOTAL)
+
+/*
+ * Total data bit time that is too short/long for a valid bit,
+ * used for error injection.
+ */
+#define CEC_TIM_DATA_BIT_TOTAL_SHORT 1800
+#define CEC_TIM_DATA_BIT_TOTAL_LONG 2900
+
+/*
+ * Total start bit time that is too short/long for a valid bit,
+ * used for error injection.
+ */
+#define CEC_TIM_START_BIT_TOTAL_SHORT 4100
+#define CEC_TIM_START_BIT_TOTAL_LONG 5000
+
+/* Data bits are 0-7, EOM is bit 8 and ACK is bit 9 */
+#define EOM_BIT 8
+#define ACK_BIT 9
+
+struct cec_state {
+ const char * const name;
+ unsigned int usecs;
+};
+
+static const struct cec_state states[CEC_PIN_STATES] = {
+ { "Off", 0 },
+ { "Idle", CEC_TIM_IDLE_SAMPLE },
+ { "Tx Wait", CEC_TIM_SAMPLE },
+ { "Tx Wait for High", CEC_TIM_IDLE_SAMPLE },
+ { "Tx Start Bit Low", CEC_TIM_START_BIT_LOW },
+ { "Tx Start Bit High", CEC_TIM_START_BIT_TOTAL - CEC_TIM_START_BIT_LOW },
+ { "Tx Start Bit High Short", CEC_TIM_START_BIT_TOTAL_SHORT - CEC_TIM_START_BIT_LOW },
+ { "Tx Start Bit High Long", CEC_TIM_START_BIT_TOTAL_LONG - CEC_TIM_START_BIT_LOW },
+ { "Tx Start Bit Low Custom", 0 },
+ { "Tx Start Bit High Custom", 0 },
+ { "Tx Data 0 Low", CEC_TIM_DATA_BIT_0_LOW },
+ { "Tx Data 0 High", CEC_TIM_DATA_BIT_TOTAL - CEC_TIM_DATA_BIT_0_LOW },
+ { "Tx Data 0 High Short", CEC_TIM_DATA_BIT_TOTAL_SHORT - CEC_TIM_DATA_BIT_0_LOW },
+ { "Tx Data 0 High Long", CEC_TIM_DATA_BIT_TOTAL_LONG - CEC_TIM_DATA_BIT_0_LOW },
+ { "Tx Data 1 Low", CEC_TIM_DATA_BIT_1_LOW },
+ { "Tx Data 1 High", CEC_TIM_DATA_BIT_TOTAL - CEC_TIM_DATA_BIT_1_LOW },
+ { "Tx Data 1 High Short", CEC_TIM_DATA_BIT_TOTAL_SHORT - CEC_TIM_DATA_BIT_1_LOW },
+ { "Tx Data 1 High Long", CEC_TIM_DATA_BIT_TOTAL_LONG - CEC_TIM_DATA_BIT_1_LOW },
+ { "Tx Data 1 High Pre Sample", CEC_TIM_DATA_BIT_SAMPLE - CEC_TIM_DATA_BIT_1_LOW },
+ { "Tx Data 1 High Post Sample", CEC_TIM_DATA_BIT_TOTAL - CEC_TIM_DATA_BIT_SAMPLE },
+ { "Tx Data 1 High Post Sample Short", CEC_TIM_DATA_BIT_TOTAL_SHORT - CEC_TIM_DATA_BIT_SAMPLE },
+ { "Tx Data 1 High Post Sample Long", CEC_TIM_DATA_BIT_TOTAL_LONG - CEC_TIM_DATA_BIT_SAMPLE },
+ { "Tx Data Bit Low Custom", 0 },
+ { "Tx Data Bit High Custom", 0 },
+ { "Tx Pulse Low Custom", 0 },
+ { "Tx Pulse High Custom", 0 },
+ { "Tx Low Drive", CEC_TIM_LOW_DRIVE_ERROR },
+ { "Rx Start Bit Low", CEC_TIM_SAMPLE },
+ { "Rx Start Bit High", CEC_TIM_SAMPLE },
+ { "Rx Data Sample", CEC_TIM_DATA_BIT_SAMPLE },
+ { "Rx Data Post Sample", CEC_TIM_DATA_BIT_HIGH - CEC_TIM_DATA_BIT_SAMPLE },
+ { "Rx Data Wait for Low", CEC_TIM_SAMPLE },
+ { "Rx Ack Low", CEC_TIM_DATA_BIT_0_LOW },
+ { "Rx Ack Low Post", CEC_TIM_DATA_BIT_HIGH - CEC_TIM_DATA_BIT_0_LOW },
+ { "Rx Ack High Post", CEC_TIM_DATA_BIT_HIGH },
+ { "Rx Ack Finish", CEC_TIM_DATA_BIT_TOTAL_MIN - CEC_TIM_DATA_BIT_HIGH },
+ { "Rx Low Drive", CEC_TIM_LOW_DRIVE_ERROR },
+ { "Rx Irq", 0 },
+};
+
+static void cec_pin_update(struct cec_pin *pin, bool v, bool force)
+{
+ if (!force && v == pin->adap->cec_pin_is_high)
+ return;
+
+ pin->adap->cec_pin_is_high = v;
+ if (atomic_read(&pin->work_pin_num_events) < CEC_NUM_PIN_EVENTS) {
+ u8 ev = v;
+
+ if (pin->work_pin_events_dropped) {
+ pin->work_pin_events_dropped = false;
+ ev |= CEC_PIN_EVENT_FL_DROPPED;
+ }
+ pin->work_pin_events[pin->work_pin_events_wr] = ev;
+ pin->work_pin_ts[pin->work_pin_events_wr] = ktime_get();
+ pin->work_pin_events_wr =
+ (pin->work_pin_events_wr + 1) % CEC_NUM_PIN_EVENTS;
+ atomic_inc(&pin->work_pin_num_events);
+ } else {
+ pin->work_pin_events_dropped = true;
+ pin->work_pin_events_dropped_cnt++;
+ }
+ wake_up_interruptible(&pin->kthread_waitq);
+}
+
+static bool cec_pin_read(struct cec_pin *pin)
+{
+ bool v = call_pin_op(pin, read);
+
+ cec_pin_update(pin, v, false);
+ return v;
+}
+
+static void cec_pin_low(struct cec_pin *pin)
+{
+ call_void_pin_op(pin, low);
+ cec_pin_update(pin, false, false);
+}
+
+static bool cec_pin_high(struct cec_pin *pin)
+{
+ call_void_pin_op(pin, high);
+ return cec_pin_read(pin);
+}
+
+static bool rx_error_inj(struct cec_pin *pin, unsigned int mode_offset,
+ int arg_idx, u8 *arg)
+{
+#ifdef CONFIG_CEC_PIN_ERROR_INJ
+ u16 cmd = cec_pin_rx_error_inj(pin);
+ u64 e = pin->error_inj[cmd];
+ unsigned int mode = (e >> mode_offset) & CEC_ERROR_INJ_MODE_MASK;
+
+ if (arg_idx >= 0) {
+ u8 pos = pin->error_inj_args[cmd][arg_idx];
+
+ if (arg)
+ *arg = pos;
+ else if (pos != pin->rx_bit)
+ return false;
+ }
+
+ switch (mode) {
+ case CEC_ERROR_INJ_MODE_ONCE:
+ pin->error_inj[cmd] &=
+ ~(CEC_ERROR_INJ_MODE_MASK << mode_offset);
+ return true;
+ case CEC_ERROR_INJ_MODE_ALWAYS:
+ return true;
+ case CEC_ERROR_INJ_MODE_TOGGLE:
+ return pin->rx_toggle;
+ default:
+ return false;
+ }
+#else
+ return false;
+#endif
+}
+
+static bool rx_nack(struct cec_pin *pin)
+{
+ return rx_error_inj(pin, CEC_ERROR_INJ_RX_NACK_OFFSET, -1, NULL);
+}
+
+static bool rx_low_drive(struct cec_pin *pin)
+{
+ return rx_error_inj(pin, CEC_ERROR_INJ_RX_LOW_DRIVE_OFFSET,
+ CEC_ERROR_INJ_RX_LOW_DRIVE_ARG_IDX, NULL);
+}
+
+static bool rx_add_byte(struct cec_pin *pin)
+{
+ return rx_error_inj(pin, CEC_ERROR_INJ_RX_ADD_BYTE_OFFSET, -1, NULL);
+}
+
+static bool rx_remove_byte(struct cec_pin *pin)
+{
+ return rx_error_inj(pin, CEC_ERROR_INJ_RX_REMOVE_BYTE_OFFSET, -1, NULL);
+}
+
+static bool rx_arb_lost(struct cec_pin *pin, u8 *poll)
+{
+ return pin->tx_msg.len == 0 &&
+ rx_error_inj(pin, CEC_ERROR_INJ_RX_ARB_LOST_OFFSET,
+ CEC_ERROR_INJ_RX_ARB_LOST_ARG_IDX, poll);
+}
+
+static bool tx_error_inj(struct cec_pin *pin, unsigned int mode_offset,
+ int arg_idx, u8 *arg)
+{
+#ifdef CONFIG_CEC_PIN_ERROR_INJ
+ u16 cmd = cec_pin_tx_error_inj(pin);
+ u64 e = pin->error_inj[cmd];
+ unsigned int mode = (e >> mode_offset) & CEC_ERROR_INJ_MODE_MASK;
+
+ if (arg_idx >= 0) {
+ u8 pos = pin->error_inj_args[cmd][arg_idx];
+
+ if (arg)
+ *arg = pos;
+ else if (pos != pin->tx_bit)
+ return false;
+ }
+
+ switch (mode) {
+ case CEC_ERROR_INJ_MODE_ONCE:
+ pin->error_inj[cmd] &=
+ ~(CEC_ERROR_INJ_MODE_MASK << mode_offset);
+ return true;
+ case CEC_ERROR_INJ_MODE_ALWAYS:
+ return true;
+ case CEC_ERROR_INJ_MODE_TOGGLE:
+ return pin->tx_toggle;
+ default:
+ return false;
+ }
+#else
+ return false;
+#endif
+}
+
+static bool tx_no_eom(struct cec_pin *pin)
+{
+ return tx_error_inj(pin, CEC_ERROR_INJ_TX_NO_EOM_OFFSET, -1, NULL);
+}
+
+static bool tx_early_eom(struct cec_pin *pin)
+{
+ return tx_error_inj(pin, CEC_ERROR_INJ_TX_EARLY_EOM_OFFSET, -1, NULL);
+}
+
+static bool tx_short_bit(struct cec_pin *pin)
+{
+ return tx_error_inj(pin, CEC_ERROR_INJ_TX_SHORT_BIT_OFFSET,
+ CEC_ERROR_INJ_TX_SHORT_BIT_ARG_IDX, NULL);
+}
+
+static bool tx_long_bit(struct cec_pin *pin)
+{
+ return tx_error_inj(pin, CEC_ERROR_INJ_TX_LONG_BIT_OFFSET,
+ CEC_ERROR_INJ_TX_LONG_BIT_ARG_IDX, NULL);
+}
+
+static bool tx_custom_bit(struct cec_pin *pin)
+{
+ return tx_error_inj(pin, CEC_ERROR_INJ_TX_CUSTOM_BIT_OFFSET,
+ CEC_ERROR_INJ_TX_CUSTOM_BIT_ARG_IDX, NULL);
+}
+
+static bool tx_short_start(struct cec_pin *pin)
+{
+ return tx_error_inj(pin, CEC_ERROR_INJ_TX_SHORT_START_OFFSET, -1, NULL);
+}
+
+static bool tx_long_start(struct cec_pin *pin)
+{
+ return tx_error_inj(pin, CEC_ERROR_INJ_TX_LONG_START_OFFSET, -1, NULL);
+}
+
+static bool tx_custom_start(struct cec_pin *pin)
+{
+ return tx_error_inj(pin, CEC_ERROR_INJ_TX_CUSTOM_START_OFFSET,
+ -1, NULL);
+}
+
+static bool tx_last_bit(struct cec_pin *pin)
+{
+ return tx_error_inj(pin, CEC_ERROR_INJ_TX_LAST_BIT_OFFSET,
+ CEC_ERROR_INJ_TX_LAST_BIT_ARG_IDX, NULL);
+}
+
+static u8 tx_add_bytes(struct cec_pin *pin)
+{
+ u8 bytes;
+
+ if (tx_error_inj(pin, CEC_ERROR_INJ_TX_ADD_BYTES_OFFSET,
+ CEC_ERROR_INJ_TX_ADD_BYTES_ARG_IDX, &bytes))
+ return bytes;
+ return 0;
+}
+
+static bool tx_remove_byte(struct cec_pin *pin)
+{
+ return tx_error_inj(pin, CEC_ERROR_INJ_TX_REMOVE_BYTE_OFFSET, -1, NULL);
+}
+
+static bool tx_low_drive(struct cec_pin *pin)
+{
+ return tx_error_inj(pin, CEC_ERROR_INJ_TX_LOW_DRIVE_OFFSET,
+ CEC_ERROR_INJ_TX_LOW_DRIVE_ARG_IDX, NULL);
+}
+
+static void cec_pin_to_idle(struct cec_pin *pin)
+{
+ /*
+ * Reset all status fields, release the bus and
+ * go to idle state.
+ */
+ pin->rx_bit = pin->tx_bit = 0;
+ pin->rx_msg.len = 0;
+ memset(pin->rx_msg.msg, 0, sizeof(pin->rx_msg.msg));
+ pin->ts = ns_to_ktime(0);
+ pin->tx_generated_poll = false;
+ pin->tx_post_eom = false;
+ if (pin->state >= CEC_ST_TX_WAIT &&
+ pin->state <= CEC_ST_TX_LOW_DRIVE)
+ pin->tx_toggle ^= 1;
+ if (pin->state >= CEC_ST_RX_START_BIT_LOW &&
+ pin->state <= CEC_ST_RX_LOW_DRIVE)
+ pin->rx_toggle ^= 1;
+ pin->state = CEC_ST_IDLE;
+}
+
+/*
+ * 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)
+{
+ bool v;
+ bool is_ack_bit, ack;
+
+ switch (pin->state) {
+ case CEC_ST_TX_WAIT_FOR_HIGH:
+ if (cec_pin_read(pin))
+ cec_pin_to_idle(pin);
+ break;
+
+ case CEC_ST_TX_START_BIT_LOW:
+ if (tx_short_start(pin)) {
+ /*
+ * Error Injection: send an invalid (too short)
+ * start pulse.
+ */
+ pin->state = CEC_ST_TX_START_BIT_HIGH_SHORT;
+ } else if (tx_long_start(pin)) {
+ /*
+ * Error Injection: send an invalid (too long)
+ * start pulse.
+ */
+ pin->state = CEC_ST_TX_START_BIT_HIGH_LONG;
+ } else {
+ pin->state = CEC_ST_TX_START_BIT_HIGH;
+ }
+ /* Generate start bit */
+ cec_pin_high(pin);
+ break;
+
+ case CEC_ST_TX_START_BIT_LOW_CUSTOM:
+ pin->state = CEC_ST_TX_START_BIT_HIGH_CUSTOM;
+ /* Generate start bit */
+ cec_pin_high(pin);
+ break;
+
+ case CEC_ST_TX_DATA_BIT_1_HIGH_POST_SAMPLE:
+ case CEC_ST_TX_DATA_BIT_1_HIGH_POST_SAMPLE_SHORT:
+ case CEC_ST_TX_DATA_BIT_1_HIGH_POST_SAMPLE_LONG:
+ if (pin->tx_nacked) {
+ cec_pin_to_idle(pin);
+ pin->tx_msg.len = 0;
+ if (pin->tx_generated_poll)
+ break;
+ pin->work_tx_ts = ts;
+ pin->work_tx_status = CEC_TX_STATUS_NACK;
+ wake_up_interruptible(&pin->kthread_waitq);
+ break;
+ }
+ fallthrough;
+ case CEC_ST_TX_DATA_BIT_0_HIGH:
+ case CEC_ST_TX_DATA_BIT_0_HIGH_SHORT:
+ case CEC_ST_TX_DATA_BIT_0_HIGH_LONG:
+ case CEC_ST_TX_DATA_BIT_1_HIGH:
+ case CEC_ST_TX_DATA_BIT_1_HIGH_SHORT:
+ case CEC_ST_TX_DATA_BIT_1_HIGH_LONG:
+ /*
+ * If the read value is 1, then all is OK, otherwise we have a
+ * low drive condition.
+ *
+ * Special case: when we generate a poll message due to an
+ * Arbitration Lost error injection, then ignore this since
+ * the pin can actually be low in that case.
+ */
+ if (!cec_pin_read(pin) && !pin->tx_generated_poll) {
+ /*
+ * It's 0, so someone detected an error and pulled the
+ * line low for 1.5 times the nominal bit period.
+ */
+ pin->tx_msg.len = 0;
+ pin->state = CEC_ST_TX_WAIT_FOR_HIGH;
+ pin->work_tx_ts = ts;
+ pin->work_tx_status = CEC_TX_STATUS_LOW_DRIVE;
+ pin->tx_low_drive_cnt++;
+ wake_up_interruptible(&pin->kthread_waitq);
+ break;
+ }
+ fallthrough;
+ case CEC_ST_TX_DATA_BIT_HIGH_CUSTOM:
+ if (tx_last_bit(pin)) {
+ /* Error Injection: just stop sending after this bit */
+ cec_pin_to_idle(pin);
+ pin->tx_msg.len = 0;
+ if (pin->tx_generated_poll)
+ break;
+ pin->work_tx_ts = ts;
+ pin->work_tx_status = CEC_TX_STATUS_OK;
+ wake_up_interruptible(&pin->kthread_waitq);
+ break;
+ }
+ pin->tx_bit++;
+ fallthrough;
+ case CEC_ST_TX_START_BIT_HIGH:
+ case CEC_ST_TX_START_BIT_HIGH_SHORT:
+ case CEC_ST_TX_START_BIT_HIGH_LONG:
+ case CEC_ST_TX_START_BIT_HIGH_CUSTOM:
+ if (tx_low_drive(pin)) {
+ /* Error injection: go to low drive */
+ cec_pin_low(pin);
+ pin->state = CEC_ST_TX_LOW_DRIVE;
+ pin->tx_msg.len = 0;
+ if (pin->tx_generated_poll)
+ break;
+ pin->work_tx_ts = ts;
+ pin->work_tx_status = CEC_TX_STATUS_LOW_DRIVE;
+ pin->tx_low_drive_cnt++;
+ wake_up_interruptible(&pin->kthread_waitq);
+ break;
+ }
+ if (pin->tx_bit / 10 >= pin->tx_msg.len + pin->tx_extra_bytes) {
+ cec_pin_to_idle(pin);
+ pin->tx_msg.len = 0;
+ if (pin->tx_generated_poll)
+ break;
+ pin->work_tx_ts = ts;
+ pin->work_tx_status = CEC_TX_STATUS_OK;
+ wake_up_interruptible(&pin->kthread_waitq);
+ break;
+ }
+
+ switch (pin->tx_bit % 10) {
+ default: {
+ /*
+ * In the CEC_ERROR_INJ_TX_ADD_BYTES case we transmit
+ * extra bytes, so pin->tx_bit / 10 can become >= 16.
+ * Generate bit values for those extra bytes instead
+ * of reading them from the transmit buffer.
+ */
+ unsigned int idx = (pin->tx_bit / 10);
+ u8 val = idx;
+
+ if (idx < pin->tx_msg.len)
+ val = pin->tx_msg.msg[idx];
+ v = val & (1 << (7 - (pin->tx_bit % 10)));
+
+ pin->state = v ? CEC_ST_TX_DATA_BIT_1_LOW :
+ CEC_ST_TX_DATA_BIT_0_LOW;
+ break;
+ }
+ case EOM_BIT: {
+ unsigned int tot_len = pin->tx_msg.len +
+ pin->tx_extra_bytes;
+ unsigned int tx_byte_idx = pin->tx_bit / 10;
+
+ v = !pin->tx_post_eom && tx_byte_idx == tot_len - 1;
+ if (tot_len > 1 && tx_byte_idx == tot_len - 2 &&
+ tx_early_eom(pin)) {
+ /* Error injection: set EOM one byte early */
+ v = true;
+ pin->tx_post_eom = true;
+ } else if (v && tx_no_eom(pin)) {
+ /* Error injection: no EOM */
+ v = false;
+ }
+ pin->state = v ? CEC_ST_TX_DATA_BIT_1_LOW :
+ CEC_ST_TX_DATA_BIT_0_LOW;
+ break;
+ }
+ case ACK_BIT:
+ pin->state = CEC_ST_TX_DATA_BIT_1_LOW;
+ break;
+ }
+ if (tx_custom_bit(pin))
+ pin->state = CEC_ST_TX_DATA_BIT_LOW_CUSTOM;
+ cec_pin_low(pin);
+ break;
+
+ case CEC_ST_TX_DATA_BIT_0_LOW:
+ case CEC_ST_TX_DATA_BIT_1_LOW:
+ v = pin->state == CEC_ST_TX_DATA_BIT_1_LOW;
+ is_ack_bit = pin->tx_bit % 10 == ACK_BIT;
+ if (v && (pin->tx_bit < 4 || is_ack_bit)) {
+ pin->state = CEC_ST_TX_DATA_BIT_1_HIGH_PRE_SAMPLE;
+ } else if (!is_ack_bit && tx_short_bit(pin)) {
+ /* Error Injection: send an invalid (too short) bit */
+ pin->state = v ? CEC_ST_TX_DATA_BIT_1_HIGH_SHORT :
+ CEC_ST_TX_DATA_BIT_0_HIGH_SHORT;
+ } else if (!is_ack_bit && tx_long_bit(pin)) {
+ /* Error Injection: send an invalid (too long) bit */
+ pin->state = v ? CEC_ST_TX_DATA_BIT_1_HIGH_LONG :
+ CEC_ST_TX_DATA_BIT_0_HIGH_LONG;
+ } else {
+ pin->state = v ? CEC_ST_TX_DATA_BIT_1_HIGH :
+ CEC_ST_TX_DATA_BIT_0_HIGH;
+ }
+ cec_pin_high(pin);
+ break;
+
+ case CEC_ST_TX_DATA_BIT_LOW_CUSTOM:
+ pin->state = CEC_ST_TX_DATA_BIT_HIGH_CUSTOM;
+ cec_pin_high(pin);
+ break;
+
+ case CEC_ST_TX_DATA_BIT_1_HIGH_PRE_SAMPLE:
+ /* Read the CEC value at the sample time */
+ v = cec_pin_read(pin);
+ is_ack_bit = pin->tx_bit % 10 == ACK_BIT;
+ /*
+ * If v == 0 and we're within the first 4 bits
+ * of the initiator, then someone else started
+ * transmitting and we lost the arbitration
+ * (i.e. the logical address of the other
+ * transmitter has more leading 0 bits in the
+ * initiator).
+ */
+ if (!v && !is_ack_bit && !pin->tx_generated_poll) {
+ pin->tx_msg.len = 0;
+ pin->work_tx_ts = ts;
+ pin->work_tx_status = CEC_TX_STATUS_ARB_LOST;
+ wake_up_interruptible(&pin->kthread_waitq);
+ pin->rx_bit = pin->tx_bit;
+ pin->tx_bit = 0;
+ memset(pin->rx_msg.msg, 0, sizeof(pin->rx_msg.msg));
+ pin->rx_msg.msg[0] = pin->tx_msg.msg[0];
+ pin->rx_msg.msg[0] &= (0xff << (8 - pin->rx_bit));
+ pin->rx_msg.len = 0;
+ pin->ts = ktime_sub_us(ts, CEC_TIM_DATA_BIT_SAMPLE);
+ pin->state = CEC_ST_RX_DATA_POST_SAMPLE;
+ pin->rx_bit++;
+ break;
+ }
+ pin->state = CEC_ST_TX_DATA_BIT_1_HIGH_POST_SAMPLE;
+ if (!is_ack_bit && tx_short_bit(pin)) {
+ /* Error Injection: send an invalid (too short) bit */
+ pin->state = CEC_ST_TX_DATA_BIT_1_HIGH_POST_SAMPLE_SHORT;
+ } else if (!is_ack_bit && tx_long_bit(pin)) {
+ /* Error Injection: send an invalid (too long) bit */
+ pin->state = CEC_ST_TX_DATA_BIT_1_HIGH_POST_SAMPLE_LONG;
+ }
+ if (!is_ack_bit)
+ break;
+ /* Was the message ACKed? */
+ ack = cec_msg_is_broadcast(&pin->tx_msg) ? v : !v;
+ if (!ack && (!pin->tx_ignore_nack_until_eom ||
+ pin->tx_bit / 10 == pin->tx_msg.len - 1) &&
+ !pin->tx_post_eom) {
+ /*
+ * Note: the CEC spec is ambiguous regarding
+ * what action to take when a NACK appears
+ * before the last byte of the payload was
+ * transmitted: either stop transmitting
+ * immediately, or wait until the last byte
+ * was transmitted.
+ *
+ * Most CEC implementations appear to stop
+ * immediately, and that's what we do here
+ * as well.
+ */
+ pin->tx_nacked = true;
+ }
+ break;
+
+ case CEC_ST_TX_PULSE_LOW_CUSTOM:
+ cec_pin_high(pin);
+ pin->state = CEC_ST_TX_PULSE_HIGH_CUSTOM;
+ break;
+
+ case CEC_ST_TX_PULSE_HIGH_CUSTOM:
+ cec_pin_to_idle(pin);
+ break;
+
+ default:
+ break;
+ }
+}
+
+/*
+ * 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)
+{
+ s32 delta;
+ bool v;
+ bool ack;
+ bool bcast, for_us;
+ u8 dest;
+ u8 poll;
+
+ switch (pin->state) {
+ /* Receive states */
+ case CEC_ST_RX_START_BIT_LOW:
+ v = cec_pin_read(pin);
+ if (!v)
+ break;
+ pin->state = CEC_ST_RX_START_BIT_HIGH;
+ delta = ktime_us_delta(ts, pin->ts);
+ /* Start bit low is too short, go back to idle */
+ if (delta < CEC_TIM_START_BIT_LOW_MIN - CEC_TIM_IDLE_SAMPLE) {
+ if (!pin->rx_start_bit_low_too_short_cnt++) {
+ pin->rx_start_bit_low_too_short_ts = ktime_to_ns(pin->ts);
+ pin->rx_start_bit_low_too_short_delta = delta;
+ }
+ cec_pin_to_idle(pin);
+ break;
+ }
+ if (rx_arb_lost(pin, &poll)) {
+ cec_msg_init(&pin->tx_msg, poll >> 4, poll & 0xf);
+ pin->tx_generated_poll = true;
+ pin->tx_extra_bytes = 0;
+ pin->state = CEC_ST_TX_START_BIT_HIGH;
+ pin->ts = ts;
+ }
+ break;
+
+ case CEC_ST_RX_START_BIT_HIGH:
+ v = cec_pin_read(pin);
+ delta = ktime_us_delta(ts, pin->ts);
+ /*
+ * Unfortunately the spec does not specify when to give up
+ * and go to idle. We just pick TOTAL_LONG.
+ */
+ if (v && delta > CEC_TIM_START_BIT_TOTAL_LONG) {
+ pin->rx_start_bit_too_long_cnt++;
+ cec_pin_to_idle(pin);
+ break;
+ }
+ if (v)
+ break;
+ /* Start bit is too short, go back to idle */
+ if (delta < CEC_TIM_START_BIT_TOTAL_MIN - CEC_TIM_IDLE_SAMPLE) {
+ if (!pin->rx_start_bit_too_short_cnt++) {
+ pin->rx_start_bit_too_short_ts = ktime_to_ns(pin->ts);
+ pin->rx_start_bit_too_short_delta = delta;
+ }
+ cec_pin_to_idle(pin);
+ break;
+ }
+ if (rx_low_drive(pin)) {
+ /* Error injection: go to low drive */
+ cec_pin_low(pin);
+ pin->state = CEC_ST_RX_LOW_DRIVE;
+ pin->rx_low_drive_cnt++;
+ break;
+ }
+ pin->state = CEC_ST_RX_DATA_SAMPLE;
+ pin->ts = ts;
+ pin->rx_eom = false;
+ break;
+
+ case CEC_ST_RX_DATA_SAMPLE:
+ v = cec_pin_read(pin);
+ pin->state = CEC_ST_RX_DATA_POST_SAMPLE;
+ switch (pin->rx_bit % 10) {
+ default:
+ if (pin->rx_bit / 10 < CEC_MAX_MSG_SIZE)
+ pin->rx_msg.msg[pin->rx_bit / 10] |=
+ v << (7 - (pin->rx_bit % 10));
+ break;
+ case EOM_BIT:
+ pin->rx_eom = v;
+ pin->rx_msg.len = pin->rx_bit / 10 + 1;
+ break;
+ case ACK_BIT:
+ break;
+ }
+ pin->rx_bit++;
+ break;
+
+ case CEC_ST_RX_DATA_POST_SAMPLE:
+ pin->state = CEC_ST_RX_DATA_WAIT_FOR_LOW;
+ break;
+
+ case CEC_ST_RX_DATA_WAIT_FOR_LOW:
+ v = cec_pin_read(pin);
+ delta = ktime_us_delta(ts, pin->ts);
+ /*
+ * Unfortunately the spec does not specify when to give up
+ * and go to idle. We just pick TOTAL_LONG.
+ */
+ if (v && delta > CEC_TIM_DATA_BIT_TOTAL_LONG) {
+ pin->rx_data_bit_too_long_cnt++;
+ cec_pin_to_idle(pin);
+ break;
+ }
+ if (v)
+ break;
+
+ if (rx_low_drive(pin)) {
+ /* Error injection: go to low drive */
+ cec_pin_low(pin);
+ pin->state = CEC_ST_RX_LOW_DRIVE;
+ pin->rx_low_drive_cnt++;
+ break;
+ }
+
+ /*
+ * Go to low drive state when the total bit time is
+ * too short.
+ */
+ if (delta < CEC_TIM_DATA_BIT_TOTAL_MIN) {
+ if (!pin->rx_data_bit_too_short_cnt++) {
+ pin->rx_data_bit_too_short_ts = ktime_to_ns(pin->ts);
+ pin->rx_data_bit_too_short_delta = delta;
+ }
+ cec_pin_low(pin);
+ pin->state = CEC_ST_RX_LOW_DRIVE;
+ pin->rx_low_drive_cnt++;
+ break;
+ }
+ pin->ts = ts;
+ if (pin->rx_bit % 10 != 9) {
+ pin->state = CEC_ST_RX_DATA_SAMPLE;
+ break;
+ }
+
+ dest = cec_msg_destination(&pin->rx_msg);
+ bcast = dest == CEC_LOG_ADDR_BROADCAST;
+ /* for_us == broadcast or directed to us */
+ for_us = bcast || (pin->la_mask & (1 << dest));
+ /* ACK bit value */
+ ack = bcast ? 1 : !for_us;
+
+ if (for_us && rx_nack(pin)) {
+ /* Error injection: toggle the ACK bit */
+ ack = !ack;
+ }
+
+ if (ack) {
+ /* No need to write to the bus, just wait */
+ pin->state = CEC_ST_RX_ACK_HIGH_POST;
+ break;
+ }
+ cec_pin_low(pin);
+ pin->state = CEC_ST_RX_ACK_LOW;
+ break;
+
+ case CEC_ST_RX_ACK_LOW:
+ cec_pin_high(pin);
+ pin->state = CEC_ST_RX_ACK_LOW_POST;
+ break;
+
+ case CEC_ST_RX_ACK_LOW_POST:
+ case CEC_ST_RX_ACK_HIGH_POST:
+ v = cec_pin_read(pin);
+ if (v && pin->rx_eom) {
+ pin->work_rx_msg = pin->rx_msg;
+ pin->work_rx_msg.rx_ts = ktime_to_ns(ts);
+ wake_up_interruptible(&pin->kthread_waitq);
+ pin->ts = ts;
+ pin->state = CEC_ST_RX_ACK_FINISH;
+ break;
+ }
+ pin->rx_bit++;
+ pin->state = CEC_ST_RX_DATA_WAIT_FOR_LOW;
+ break;
+
+ case CEC_ST_RX_ACK_FINISH:
+ cec_pin_to_idle(pin);
+ break;
+
+ default:
+ break;
+ }
+}
+
+/*
+ * Main timer function
+ *
+ */
+static enum hrtimer_restart cec_pin_timer(struct hrtimer *timer)
+{
+ struct cec_pin *pin = container_of(timer, struct cec_pin, timer);
+ struct cec_adapter *adap = pin->adap;
+ ktime_t ts;
+ s32 delta;
+ u32 usecs;
+
+ ts = ktime_get();
+ if (ktime_to_ns(pin->timer_ts)) {
+ delta = ktime_us_delta(ts, pin->timer_ts);
+ pin->timer_cnt++;
+ if (delta > 100 && pin->state != CEC_ST_IDLE) {
+ /* Keep track of timer overruns */
+ pin->timer_sum_overrun += delta;
+ pin->timer_100us_overruns++;
+ if (delta > 300)
+ pin->timer_300us_overruns++;
+ if (delta > pin->timer_max_overrun)
+ pin->timer_max_overrun = delta;
+ }
+ }
+ if (adap->monitor_pin_cnt)
+ cec_pin_read(pin);
+
+ if (pin->wait_usecs) {
+ /*
+ * If we are monitoring the pin, then we have to
+ * sample at regular intervals.
+ */
+ if (pin->wait_usecs > 150) {
+ pin->wait_usecs -= 100;
+ pin->timer_ts = ktime_add_us(ts, 100);
+ hrtimer_forward_now(timer, ns_to_ktime(100000));
+ return HRTIMER_RESTART;
+ }
+ if (pin->wait_usecs > 100) {
+ pin->wait_usecs /= 2;
+ pin->timer_ts = ktime_add_us(ts, pin->wait_usecs);
+ hrtimer_forward_now(timer,
+ ns_to_ktime(pin->wait_usecs * 1000));
+ return HRTIMER_RESTART;
+ }
+ pin->timer_ts = ktime_add_us(ts, pin->wait_usecs);
+ hrtimer_forward_now(timer,
+ ns_to_ktime(pin->wait_usecs * 1000));
+ pin->wait_usecs = 0;
+ return HRTIMER_RESTART;
+ }
+
+ switch (pin->state) {
+ /* Transmit states */
+ case CEC_ST_TX_WAIT_FOR_HIGH:
+ case CEC_ST_TX_START_BIT_LOW:
+ case CEC_ST_TX_START_BIT_HIGH:
+ case CEC_ST_TX_START_BIT_HIGH_SHORT:
+ case CEC_ST_TX_START_BIT_HIGH_LONG:
+ case CEC_ST_TX_START_BIT_LOW_CUSTOM:
+ case CEC_ST_TX_START_BIT_HIGH_CUSTOM:
+ case CEC_ST_TX_DATA_BIT_0_LOW:
+ case CEC_ST_TX_DATA_BIT_0_HIGH:
+ case CEC_ST_TX_DATA_BIT_0_HIGH_SHORT:
+ case CEC_ST_TX_DATA_BIT_0_HIGH_LONG:
+ case CEC_ST_TX_DATA_BIT_1_LOW:
+ case CEC_ST_TX_DATA_BIT_1_HIGH:
+ case CEC_ST_TX_DATA_BIT_1_HIGH_SHORT:
+ case CEC_ST_TX_DATA_BIT_1_HIGH_LONG:
+ case CEC_ST_TX_DATA_BIT_1_HIGH_PRE_SAMPLE:
+ case CEC_ST_TX_DATA_BIT_1_HIGH_POST_SAMPLE:
+ case CEC_ST_TX_DATA_BIT_1_HIGH_POST_SAMPLE_SHORT:
+ case CEC_ST_TX_DATA_BIT_1_HIGH_POST_SAMPLE_LONG:
+ case CEC_ST_TX_DATA_BIT_LOW_CUSTOM:
+ case CEC_ST_TX_DATA_BIT_HIGH_CUSTOM:
+ case CEC_ST_TX_PULSE_LOW_CUSTOM:
+ case CEC_ST_TX_PULSE_HIGH_CUSTOM:
+ cec_pin_tx_states(pin, ts);
+ break;
+
+ /* Receive states */
+ case CEC_ST_RX_START_BIT_LOW:
+ case CEC_ST_RX_START_BIT_HIGH:
+ case CEC_ST_RX_DATA_SAMPLE:
+ case CEC_ST_RX_DATA_POST_SAMPLE:
+ case CEC_ST_RX_DATA_WAIT_FOR_LOW:
+ case CEC_ST_RX_ACK_LOW:
+ case CEC_ST_RX_ACK_LOW_POST:
+ case CEC_ST_RX_ACK_HIGH_POST:
+ case CEC_ST_RX_ACK_FINISH:
+ cec_pin_rx_states(pin, ts);
+ break;
+
+ case CEC_ST_IDLE:
+ case CEC_ST_TX_WAIT:
+ if (!cec_pin_high(pin)) {
+ /* Start bit, switch to receive state */
+ pin->ts = ts;
+ pin->state = CEC_ST_RX_START_BIT_LOW;
+ /*
+ * If a transmit is pending, then that transmit should
+ * use a signal free time of no more than
+ * CEC_SIGNAL_FREE_TIME_NEW_INITIATOR since it will
+ * have a new initiator due to the receive that is now
+ * starting.
+ */
+ if (pin->tx_msg.len && pin->tx_signal_free_time >
+ CEC_SIGNAL_FREE_TIME_NEW_INITIATOR)
+ pin->tx_signal_free_time =
+ CEC_SIGNAL_FREE_TIME_NEW_INITIATOR;
+ break;
+ }
+ if (ktime_to_ns(pin->ts) == 0)
+ pin->ts = ts;
+ if (pin->tx_msg.len) {
+ /*
+ * Check if the bus has been free for long enough
+ * so we can kick off the pending transmit.
+ */
+ delta = ktime_us_delta(ts, pin->ts);
+ if (delta / CEC_TIM_DATA_BIT_TOTAL >=
+ pin->tx_signal_free_time) {
+ pin->tx_nacked = false;
+ if (tx_custom_start(pin))
+ pin->state = CEC_ST_TX_START_BIT_LOW_CUSTOM;
+ else
+ pin->state = CEC_ST_TX_START_BIT_LOW;
+ /* Generate start bit */
+ cec_pin_low(pin);
+ break;
+ }
+ if (delta / CEC_TIM_DATA_BIT_TOTAL >=
+ pin->tx_signal_free_time - 1)
+ pin->state = CEC_ST_TX_WAIT;
+ break;
+ }
+ if (pin->tx_custom_pulse && pin->state == CEC_ST_IDLE) {
+ pin->tx_custom_pulse = false;
+ /* Generate custom pulse */
+ cec_pin_low(pin);
+ pin->state = CEC_ST_TX_PULSE_LOW_CUSTOM;
+ break;
+ }
+ if (pin->state != CEC_ST_IDLE || pin->ops->enable_irq == NULL ||
+ pin->enable_irq_failed || adap->is_configuring ||
+ adap->is_configured || adap->monitor_all_cnt)
+ break;
+ /* Switch to interrupt mode */
+ atomic_set(&pin->work_irq_change, CEC_PIN_IRQ_ENABLE);
+ pin->state = CEC_ST_RX_IRQ;
+ wake_up_interruptible(&pin->kthread_waitq);
+ return HRTIMER_NORESTART;
+
+ case CEC_ST_TX_LOW_DRIVE:
+ case CEC_ST_RX_LOW_DRIVE:
+ cec_pin_high(pin);
+ cec_pin_to_idle(pin);
+ break;
+
+ default:
+ break;
+ }
+
+ switch (pin->state) {
+ case CEC_ST_TX_START_BIT_LOW_CUSTOM:
+ case CEC_ST_TX_DATA_BIT_LOW_CUSTOM:
+ case CEC_ST_TX_PULSE_LOW_CUSTOM:
+ usecs = pin->tx_custom_low_usecs;
+ break;
+ case CEC_ST_TX_START_BIT_HIGH_CUSTOM:
+ case CEC_ST_TX_DATA_BIT_HIGH_CUSTOM:
+ case CEC_ST_TX_PULSE_HIGH_CUSTOM:
+ usecs = pin->tx_custom_high_usecs;
+ break;
+ default:
+ usecs = states[pin->state].usecs;
+ break;
+ }
+
+ if (!adap->monitor_pin_cnt || usecs <= 150) {
+ pin->wait_usecs = 0;
+ pin->timer_ts = ktime_add_us(ts, usecs);
+ hrtimer_forward_now(timer,
+ ns_to_ktime(usecs * 1000));
+ return HRTIMER_RESTART;
+ }
+ pin->wait_usecs = usecs - 100;
+ pin->timer_ts = ktime_add_us(ts, 100);
+ hrtimer_forward_now(timer, ns_to_ktime(100000));
+ return HRTIMER_RESTART;
+}
+
+static int cec_pin_thread_func(void *_adap)
+{
+ struct cec_adapter *adap = _adap;
+ struct cec_pin *pin = adap->pin;
+ bool irq_enabled = false;
+
+ for (;;) {
+ wait_event_interruptible(pin->kthread_waitq,
+ kthread_should_stop() ||
+ pin->work_rx_msg.len ||
+ pin->work_tx_status ||
+ atomic_read(&pin->work_irq_change) ||
+ atomic_read(&pin->work_pin_num_events));
+
+ if (kthread_should_stop())
+ break;
+
+ if (pin->work_rx_msg.len) {
+ struct cec_msg *msg = &pin->work_rx_msg;
+
+ if (msg->len > 1 && msg->len < CEC_MAX_MSG_SIZE &&
+ rx_add_byte(pin)) {
+ /* Error injection: add byte to the message */
+ msg->msg[msg->len++] = 0x55;
+ }
+ if (msg->len > 2 && rx_remove_byte(pin)) {
+ /* Error injection: remove byte from message */
+ msg->len--;
+ }
+ if (msg->len > CEC_MAX_MSG_SIZE)
+ msg->len = CEC_MAX_MSG_SIZE;
+ cec_received_msg_ts(adap, msg,
+ ns_to_ktime(pin->work_rx_msg.rx_ts));
+ msg->len = 0;
+ }
+
+ if (pin->work_tx_status) {
+ unsigned int tx_status = pin->work_tx_status;
+
+ pin->work_tx_status = 0;
+ cec_transmit_attempt_done_ts(adap, tx_status,
+ pin->work_tx_ts);
+ }
+
+ while (atomic_read(&pin->work_pin_num_events)) {
+ unsigned int idx = pin->work_pin_events_rd;
+ u8 v = pin->work_pin_events[idx];
+
+ cec_queue_pin_cec_event(adap,
+ v & CEC_PIN_EVENT_FL_IS_HIGH,
+ v & CEC_PIN_EVENT_FL_DROPPED,
+ pin->work_pin_ts[idx]);
+ pin->work_pin_events_rd = (idx + 1) % CEC_NUM_PIN_EVENTS;
+ atomic_dec(&pin->work_pin_num_events);
+ }
+
+ switch (atomic_xchg(&pin->work_irq_change,
+ CEC_PIN_IRQ_UNCHANGED)) {
+ case CEC_PIN_IRQ_DISABLE:
+ if (irq_enabled) {
+ call_void_pin_op(pin, disable_irq);
+ irq_enabled = false;
+ }
+ cec_pin_high(pin);
+ if (pin->state == CEC_ST_OFF)
+ break;
+ cec_pin_to_idle(pin);
+ hrtimer_start(&pin->timer, ns_to_ktime(0),
+ HRTIMER_MODE_REL);
+ break;
+ case CEC_PIN_IRQ_ENABLE:
+ if (irq_enabled)
+ break;
+ pin->enable_irq_failed = !call_pin_op(pin, enable_irq);
+ if (pin->enable_irq_failed) {
+ cec_pin_to_idle(pin);
+ hrtimer_start(&pin->timer, ns_to_ktime(0),
+ HRTIMER_MODE_REL);
+ } else {
+ irq_enabled = true;
+ }
+ break;
+ default:
+ break;
+ }
+ }
+ return 0;
+}
+
+static int cec_pin_adap_enable(struct cec_adapter *adap, bool enable)
+{
+ struct cec_pin *pin = adap->pin;
+
+ if (enable) {
+ cec_pin_read(pin);
+ cec_pin_to_idle(pin);
+ pin->tx_msg.len = 0;
+ pin->timer_ts = ns_to_ktime(0);
+ atomic_set(&pin->work_irq_change, CEC_PIN_IRQ_UNCHANGED);
+ if (!pin->kthread) {
+ pin->kthread = kthread_run(cec_pin_thread_func, adap,
+ "cec-pin");
+ if (IS_ERR(pin->kthread)) {
+ int err = PTR_ERR(pin->kthread);
+
+ pr_err("cec-pin: kernel_thread() failed\n");
+ pin->kthread = NULL;
+ return err;
+ }
+ }
+ hrtimer_start(&pin->timer, ns_to_ktime(0),
+ HRTIMER_MODE_REL);
+ } else if (pin->kthread) {
+ hrtimer_cancel(&pin->timer);
+ cec_pin_high(pin);
+ cec_pin_to_idle(pin);
+ pin->state = CEC_ST_OFF;
+ pin->work_tx_status = 0;
+ atomic_set(&pin->work_irq_change, CEC_PIN_IRQ_DISABLE);
+ wake_up_interruptible(&pin->kthread_waitq);
+ }
+ return 0;
+}
+
+static int cec_pin_adap_log_addr(struct cec_adapter *adap, u8 log_addr)
+{
+ struct cec_pin *pin = adap->pin;
+
+ if (log_addr == CEC_LOG_ADDR_INVALID)
+ pin->la_mask = 0;
+ else
+ pin->la_mask |= (1 << log_addr);
+ return 0;
+}
+
+void cec_pin_start_timer(struct cec_pin *pin)
+{
+ if (pin->state != CEC_ST_RX_IRQ)
+ return;
+
+ atomic_set(&pin->work_irq_change, CEC_PIN_IRQ_DISABLE);
+ wake_up_interruptible(&pin->kthread_waitq);
+}
+
+static int cec_pin_adap_transmit(struct cec_adapter *adap, u8 attempts,
+ u32 signal_free_time, struct cec_msg *msg)
+{
+ struct cec_pin *pin = adap->pin;
+
+ /*
+ * If a receive is in progress, then this transmit should use
+ * a signal free time of max CEC_SIGNAL_FREE_TIME_NEW_INITIATOR
+ * since when it starts transmitting it will have a new initiator.
+ */
+ if (pin->state != CEC_ST_IDLE &&
+ signal_free_time > CEC_SIGNAL_FREE_TIME_NEW_INITIATOR)
+ signal_free_time = CEC_SIGNAL_FREE_TIME_NEW_INITIATOR;
+
+ pin->tx_signal_free_time = signal_free_time;
+ pin->tx_extra_bytes = 0;
+ pin->tx_msg = *msg;
+ if (msg->len > 1) {
+ /* Error injection: add byte to the message */
+ pin->tx_extra_bytes = tx_add_bytes(pin);
+ }
+ if (msg->len > 2 && tx_remove_byte(pin)) {
+ /* Error injection: remove byte from the message */
+ pin->tx_msg.len--;
+ }
+ pin->work_tx_status = 0;
+ pin->tx_bit = 0;
+ cec_pin_start_timer(pin);
+ return 0;
+}
+
+static void cec_pin_adap_status(struct cec_adapter *adap,
+ struct seq_file *file)
+{
+ struct cec_pin *pin = adap->pin;
+
+ seq_printf(file, "state: %s\n", states[pin->state].name);
+ seq_printf(file, "tx_bit: %d\n", pin->tx_bit);
+ seq_printf(file, "rx_bit: %d\n", pin->rx_bit);
+ seq_printf(file, "cec pin: %d\n", call_pin_op(pin, read));
+ seq_printf(file, "cec pin events dropped: %u\n",
+ pin->work_pin_events_dropped_cnt);
+ seq_printf(file, "irq failed: %d\n", pin->enable_irq_failed);
+ if (pin->timer_100us_overruns) {
+ seq_printf(file, "timer overruns > 100us: %u of %u\n",
+ pin->timer_100us_overruns, pin->timer_cnt);
+ seq_printf(file, "timer overruns > 300us: %u of %u\n",
+ pin->timer_300us_overruns, pin->timer_cnt);
+ seq_printf(file, "max timer overrun: %u usecs\n",
+ pin->timer_max_overrun);
+ seq_printf(file, "avg timer overrun: %u usecs\n",
+ pin->timer_sum_overrun / pin->timer_100us_overruns);
+ }
+ if (pin->rx_start_bit_low_too_short_cnt)
+ seq_printf(file,
+ "rx start bit low too short: %u (delta %u, ts %llu)\n",
+ pin->rx_start_bit_low_too_short_cnt,
+ pin->rx_start_bit_low_too_short_delta,
+ pin->rx_start_bit_low_too_short_ts);
+ if (pin->rx_start_bit_too_short_cnt)
+ seq_printf(file,
+ "rx start bit too short: %u (delta %u, ts %llu)\n",
+ pin->rx_start_bit_too_short_cnt,
+ pin->rx_start_bit_too_short_delta,
+ pin->rx_start_bit_too_short_ts);
+ if (pin->rx_start_bit_too_long_cnt)
+ seq_printf(file, "rx start bit too long: %u\n",
+ pin->rx_start_bit_too_long_cnt);
+ if (pin->rx_data_bit_too_short_cnt)
+ seq_printf(file,
+ "rx data bit too short: %u (delta %u, ts %llu)\n",
+ pin->rx_data_bit_too_short_cnt,
+ pin->rx_data_bit_too_short_delta,
+ pin->rx_data_bit_too_short_ts);
+ if (pin->rx_data_bit_too_long_cnt)
+ seq_printf(file, "rx data bit too long: %u\n",
+ pin->rx_data_bit_too_long_cnt);
+ seq_printf(file, "rx initiated low drive: %u\n", pin->rx_low_drive_cnt);
+ seq_printf(file, "tx detected low drive: %u\n", pin->tx_low_drive_cnt);
+ pin->work_pin_events_dropped_cnt = 0;
+ pin->timer_cnt = 0;
+ pin->timer_100us_overruns = 0;
+ pin->timer_300us_overruns = 0;
+ pin->timer_max_overrun = 0;
+ pin->timer_sum_overrun = 0;
+ pin->rx_start_bit_low_too_short_cnt = 0;
+ pin->rx_start_bit_too_short_cnt = 0;
+ pin->rx_start_bit_too_long_cnt = 0;
+ pin->rx_data_bit_too_short_cnt = 0;
+ pin->rx_data_bit_too_long_cnt = 0;
+ pin->rx_low_drive_cnt = 0;
+ pin->tx_low_drive_cnt = 0;
+ call_void_pin_op(pin, status, file);
+}
+
+static int cec_pin_adap_monitor_all_enable(struct cec_adapter *adap,
+ bool enable)
+{
+ struct cec_pin *pin = adap->pin;
+
+ pin->monitor_all = enable;
+ return 0;
+}
+
+static void cec_pin_adap_free(struct cec_adapter *adap)
+{
+ struct cec_pin *pin = adap->pin;
+
+ if (pin->kthread)
+ kthread_stop(pin->kthread);
+ pin->kthread = NULL;
+ if (pin->ops->free)
+ pin->ops->free(adap);
+ adap->pin = NULL;
+ kfree(pin);
+}
+
+static int cec_pin_received(struct cec_adapter *adap, struct cec_msg *msg)
+{
+ struct cec_pin *pin = adap->pin;
+
+ if (pin->ops->received && !adap->devnode.unregistered)
+ return pin->ops->received(adap, msg);
+ return -ENOMSG;
+}
+
+void cec_pin_changed(struct cec_adapter *adap, bool value)
+{
+ struct cec_pin *pin = adap->pin;
+
+ cec_pin_update(pin, value, false);
+ if (!value && (adap->is_configuring || adap->is_configured ||
+ adap->monitor_all_cnt))
+ atomic_set(&pin->work_irq_change, CEC_PIN_IRQ_DISABLE);
+}
+EXPORT_SYMBOL_GPL(cec_pin_changed);
+
+static const struct cec_adap_ops cec_pin_adap_ops = {
+ .adap_enable = cec_pin_adap_enable,
+ .adap_monitor_all_enable = cec_pin_adap_monitor_all_enable,
+ .adap_log_addr = cec_pin_adap_log_addr,
+ .adap_transmit = cec_pin_adap_transmit,
+ .adap_status = cec_pin_adap_status,
+ .adap_free = cec_pin_adap_free,
+#ifdef CONFIG_CEC_PIN_ERROR_INJ
+ .error_inj_parse_line = cec_pin_error_inj_parse_line,
+ .error_inj_show = cec_pin_error_inj_show,
+#endif
+ .received = cec_pin_received,
+};
+
+struct cec_adapter *cec_pin_allocate_adapter(const struct cec_pin_ops *pin_ops,
+ void *priv, const char *name, u32 caps)
+{
+ struct cec_adapter *adap;
+ struct cec_pin *pin = kzalloc(sizeof(*pin), GFP_KERNEL);
+
+ if (pin == NULL)
+ return ERR_PTR(-ENOMEM);
+ pin->ops = pin_ops;
+ hrtimer_init(&pin->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ atomic_set(&pin->work_pin_num_events, 0);
+ pin->timer.function = cec_pin_timer;
+ init_waitqueue_head(&pin->kthread_waitq);
+ pin->tx_custom_low_usecs = CEC_TIM_CUSTOM_DEFAULT;
+ pin->tx_custom_high_usecs = CEC_TIM_CUSTOM_DEFAULT;
+
+ adap = cec_allocate_adapter(&cec_pin_adap_ops, priv, name,
+ caps | CEC_CAP_MONITOR_ALL | CEC_CAP_MONITOR_PIN,
+ CEC_MAX_LOG_ADDRS);
+
+ if (IS_ERR(adap)) {
+ kfree(pin);
+ return adap;
+ }
+
+ adap->pin = pin;
+ pin->adap = adap;
+ cec_pin_update(pin, cec_pin_high(pin), true);
+ return adap;
+}
+EXPORT_SYMBOL_GPL(cec_pin_allocate_adapter);