1 // SPDX-License-Identifier: GPL-2.0-only
6  * Generic PWM trigger for SPI offload.
16 #include <linux/pwm.h>
24 	struct pwm_device *pwm;  member
27 static bool spi_offload_trigger_pwm_match(struct spi_offload_trigger *trigger,  in spi_offload_trigger_pwm_match()  argument
37 static int spi_offload_trigger_pwm_validate(struct spi_offload_trigger *trigger,  in spi_offload_trigger_pwm_validate()  argument
40 	struct spi_offload_trigger_pwm_state *st = spi_offload_trigger_get_priv(trigger);  in spi_offload_trigger_pwm_validate()
41 	struct spi_offload_trigger_periodic *periodic = &config->periodic;  in spi_offload_trigger_pwm_validate()
45 	if (config->type != SPI_OFFLOAD_TRIGGER_PERIODIC)  in spi_offload_trigger_pwm_validate()
46 		return -EINVAL;  in spi_offload_trigger_pwm_validate()
48 	if (!periodic->frequency_hz)  in spi_offload_trigger_pwm_validate()
49 		return -EINVAL;  in spi_offload_trigger_pwm_validate()
51 	wf.period_length_ns = DIV_ROUND_UP_ULL(NSEC_PER_SEC, periodic->frequency_hz);  in spi_offload_trigger_pwm_validate()
52 	/* REVISIT: 50% duty-cycle for now - may add config parameter later */  in spi_offload_trigger_pwm_validate()
55 	ret = pwm_round_waveform_might_sleep(st->pwm, &wf);  in spi_offload_trigger_pwm_validate()
59 	periodic->frequency_hz = DIV_ROUND_UP_ULL(NSEC_PER_SEC, wf.period_length_ns);  in spi_offload_trigger_pwm_validate()
64 static int spi_offload_trigger_pwm_enable(struct spi_offload_trigger *trigger,  in spi_offload_trigger_pwm_enable()  argument
67 	struct spi_offload_trigger_pwm_state *st = spi_offload_trigger_get_priv(trigger);  in spi_offload_trigger_pwm_enable()
68 	struct spi_offload_trigger_periodic *periodic = &config->periodic;  in spi_offload_trigger_pwm_enable()
71 	if (config->type != SPI_OFFLOAD_TRIGGER_PERIODIC)  in spi_offload_trigger_pwm_enable()
72 		return -EINVAL;  in spi_offload_trigger_pwm_enable()
74 	if (!periodic->frequency_hz)  in spi_offload_trigger_pwm_enable()
75 		return -EINVAL;  in spi_offload_trigger_pwm_enable()
77 	wf.period_length_ns = DIV_ROUND_UP_ULL(NSEC_PER_SEC, periodic->frequency_hz);  in spi_offload_trigger_pwm_enable()
78 	/* REVISIT: 50% duty-cycle for now - may add config parameter later */  in spi_offload_trigger_pwm_enable()
81 	return pwm_set_waveform_might_sleep(st->pwm, &wf, false);  in spi_offload_trigger_pwm_enable()
84 static void spi_offload_trigger_pwm_disable(struct spi_offload_trigger *trigger)  in spi_offload_trigger_pwm_disable()  argument
86 	struct spi_offload_trigger_pwm_state *st = spi_offload_trigger_get_priv(trigger);  in spi_offload_trigger_pwm_disable()
90 	ret = pwm_get_waveform_might_sleep(st->pwm, &wf);  in spi_offload_trigger_pwm_disable()
92 		dev_err(st->dev, "failed to get waveform: %d\n", ret);  in spi_offload_trigger_pwm_disable()
98 	ret = pwm_set_waveform_might_sleep(st->pwm, &wf, false);  in spi_offload_trigger_pwm_disable()
100 		dev_err(st->dev, "failed to disable PWM: %d\n", ret);  in spi_offload_trigger_pwm_disable()
117 	struct device *dev = &pdev->dev;  in spi_offload_trigger_pwm_probe()
128 		return -ENOMEM;  in spi_offload_trigger_pwm_probe()
131 	st->dev = dev;  in spi_offload_trigger_pwm_probe()
133 	st->pwm = devm_pwm_get(dev, NULL);  in spi_offload_trigger_pwm_probe()
134 	if (IS_ERR(st->pwm))  in spi_offload_trigger_pwm_probe()
135 		return dev_err_probe(dev, PTR_ERR(st->pwm), "failed to get PWM\n");  in spi_offload_trigger_pwm_probe()
137 	/* init with duty_cycle = 0, output enabled to ensure trigger off */  in spi_offload_trigger_pwm_probe()
138 	pwm_init_state(st->pwm, &state);  in spi_offload_trigger_pwm_probe()
141 	ret = pwm_apply_might_sleep(st->pwm, &state);  in spi_offload_trigger_pwm_probe()
143 		return dev_err_probe(dev, ret, "failed to apply PWM state\n");  in spi_offload_trigger_pwm_probe()
145 	ret = devm_add_action_or_reset(dev, spi_offload_trigger_pwm_release, st->pwm);  in spi_offload_trigger_pwm_probe()
153 	{ .compatible = "pwm-trigger" },
160 		.name = "pwm-trigger",
168 MODULE_DESCRIPTION("Generic PWM trigger");