diff options
Diffstat (limited to 'drivers/media/rc/pwm-ir-tx.c')
| -rw-r--r-- | drivers/media/rc/pwm-ir-tx.c | 86 |
1 files changed, 78 insertions, 8 deletions
diff --git a/drivers/media/rc/pwm-ir-tx.c b/drivers/media/rc/pwm-ir-tx.c index 105a9c24f1e3..047472dc9244 100644 --- a/drivers/media/rc/pwm-ir-tx.c +++ b/drivers/media/rc/pwm-ir-tx.c @@ -10,6 +10,8 @@ #include <linux/slab.h> #include <linux/of.h> #include <linux/platform_device.h> +#include <linux/hrtimer.h> +#include <linux/completion.h> #include <media/rc-core.h> #define DRIVER_NAME "pwm-ir-tx" @@ -17,12 +19,19 @@ struct pwm_ir { struct pwm_device *pwm; - unsigned int carrier; - unsigned int duty_cycle; + struct hrtimer timer; + struct completion tx_done; + struct pwm_state *state; + u32 carrier; + u32 duty_cycle; + const unsigned int *txbuf; + unsigned int txbuf_len; + unsigned int txbuf_index; }; static const struct of_device_id pwm_ir_of_match[] = { { .compatible = "pwm-ir-tx", }, + { .compatible = "nokia,n900-ir" }, { }, }; MODULE_DEVICE_TABLE(of, pwm_ir_of_match); @@ -48,8 +57,8 @@ static int pwm_ir_set_carrier(struct rc_dev *dev, u32 carrier) return 0; } -static int pwm_ir_tx(struct rc_dev *dev, unsigned int *txbuf, - unsigned int count) +static int pwm_ir_tx_sleep(struct rc_dev *dev, unsigned int *txbuf, + unsigned int count) { struct pwm_ir *pwm_ir = dev->priv; struct pwm_device *pwm = pwm_ir->pwm; @@ -67,7 +76,7 @@ static int pwm_ir_tx(struct rc_dev *dev, unsigned int *txbuf, for (i = 0; i < count; i++) { state.enabled = !(i % 2); - pwm_apply_state(pwm, &state); + pwm_apply_might_sleep(pwm, &state); edge = ktime_add_us(edge, txbuf[i]); delta = ktime_us_delta(edge, ktime_get()); @@ -76,11 +85,64 @@ static int pwm_ir_tx(struct rc_dev *dev, unsigned int *txbuf, } state.enabled = false; - pwm_apply_state(pwm, &state); + pwm_apply_might_sleep(pwm, &state); return count; } +static int pwm_ir_tx_atomic(struct rc_dev *dev, unsigned int *txbuf, + unsigned int count) +{ + struct pwm_ir *pwm_ir = dev->priv; + struct pwm_device *pwm = pwm_ir->pwm; + struct pwm_state state; + + pwm_init_state(pwm, &state); + + state.period = DIV_ROUND_CLOSEST(NSEC_PER_SEC, pwm_ir->carrier); + pwm_set_relative_duty_cycle(&state, pwm_ir->duty_cycle, 100); + + pwm_ir->txbuf = txbuf; + pwm_ir->txbuf_len = count; + pwm_ir->txbuf_index = 0; + pwm_ir->state = &state; + + hrtimer_start(&pwm_ir->timer, 0, HRTIMER_MODE_REL); + + wait_for_completion(&pwm_ir->tx_done); + + return count; +} + +static enum hrtimer_restart pwm_ir_timer(struct hrtimer *timer) +{ + struct pwm_ir *pwm_ir = container_of(timer, struct pwm_ir, timer); + + /* + * If we happen to hit an odd latency spike, loop through the + * pulses until we catch up. + */ + do { + u64 ns; + + pwm_ir->state->enabled = !(pwm_ir->txbuf_index % 2); + pwm_apply_atomic(pwm_ir->pwm, pwm_ir->state); + + if (pwm_ir->txbuf_index >= pwm_ir->txbuf_len) { + complete(&pwm_ir->tx_done); + + return HRTIMER_NORESTART; + } + + ns = US_TO_NS(pwm_ir->txbuf[pwm_ir->txbuf_index]); + hrtimer_add_expires_ns(timer, ns); + + pwm_ir->txbuf_index++; + } while (hrtimer_expires_remaining(timer) > 0); + + return HRTIMER_RESTART; +} + static int pwm_ir_probe(struct platform_device *pdev) { struct pwm_ir *pwm_ir; @@ -102,10 +164,18 @@ static int pwm_ir_probe(struct platform_device *pdev) if (!rcdev) return -ENOMEM; + if (pwm_might_sleep(pwm_ir->pwm)) { + dev_info(&pdev->dev, "TX will not be accurate as PWM device might sleep\n"); + rcdev->tx_ir = pwm_ir_tx_sleep; + } else { + init_completion(&pwm_ir->tx_done); + hrtimer_setup(&pwm_ir->timer, pwm_ir_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + rcdev->tx_ir = pwm_ir_tx_atomic; + } + rcdev->priv = pwm_ir; rcdev->driver_name = DRIVER_NAME; rcdev->device_name = DEVICE_NAME; - rcdev->tx_ir = pwm_ir_tx; rcdev->s_tx_duty_cycle = pwm_ir_set_duty_cycle; rcdev->s_tx_carrier = pwm_ir_set_carrier; @@ -120,7 +190,7 @@ static struct platform_driver pwm_ir_driver = { .probe = pwm_ir_probe, .driver = { .name = DRIVER_NAME, - .of_match_table = of_match_ptr(pwm_ir_of_match), + .of_match_table = pwm_ir_of_match, }, }; module_platform_driver(pwm_ir_driver); |