| Message ID | 20241211-dlech-mainline-spi-engine-offload-2-v6-4-88ee574d5d03@baylibre.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | spi: axi-spi-engine: add offload support | expand |
On Wed, 2024-12-11 at 14:54 -0600, David Lechner wrote: > Add a new driver for a generic PWM trigger for SPI offloads. > > Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> > Signed-off-by: David Lechner <dlechner@baylibre.com> > --- Still don't really agree with always checking against SPI_OFFLOAD_TRIGGER_PERIODIC. But yeah... Reviewed-by: Nuno Sa <nuno.sa@analog.com> > > v6 changes: > * Use dev instead of &pdev->dev > * Swap order of "pwm" and "trigger" in name to follow "pwm-clock" > precedent. > > v5 changes: > * Updated to accommodate changes in other patches in this series. > * Add MAINTAINERS entry. > > v4 changes: new patch in v4 > --- > MAINTAINERS | 1 + > drivers/spi/Kconfig | 12 +++ > drivers/spi/Makefile | 3 + > drivers/spi/spi-offload-trigger-pwm.c | 162 > ++++++++++++++++++++++++++++++++++ > 4 files changed, 178 insertions(+) > > diff --git a/MAINTAINERS b/MAINTAINERS > index > b2aa6f37743e48353c60e5973ea8126590c7f6d5..d8d72da5ac4bcab817a515774eb8db37a7e9 > 4f25 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -22131,6 +22131,7 @@ F: include/linux/mtd/spi-nor.h > > SPI OFFLOAD > R: David Lechner <dlechner@baylibre.com> > +F: drivers/spi/spi-offload-trigger-pwm.c > F: drivers/spi/spi-offload.c > F: include/linux/spi/spi-offload.h > K: spi_offload > diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig > index > 02064a4e292815ec0213e2e446b4f90ed8855a52..2cfc14be869790f5226130428bb7cb40aadf > b031 100644 > --- a/drivers/spi/Kconfig > +++ b/drivers/spi/Kconfig > @@ -1320,4 +1320,16 @@ endif # SPI_SLAVE > config SPI_DYNAMIC > def_bool ACPI || OF_DYNAMIC || SPI_SLAVE > > +if SPI_OFFLOAD > + > +comment "SPI Offload triggers" > + > +config SPI_OFFLOAD_TRIGGER_PWM > + tristate "SPI offload trigger using PWM" > + depends on PWM > + help > + Generic SPI offload trigger implemented using PWM output. > + > +endif # SPI_OFFLOAD > + > endif # SPI > diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile > index > bb5fc20df21332232533c2e70c0cc230f6bcf27f..0068d170bc99c750c13376c4013991d927bb > ac63 100644 > --- a/drivers/spi/Makefile > +++ b/drivers/spi/Makefile > @@ -164,3 +164,6 @@ obj-$(CONFIG_SPI_AMD) += spi-amd.o > # SPI slave protocol handlers > obj-$(CONFIG_SPI_SLAVE_TIME) += spi-slave-time.o > obj-$(CONFIG_SPI_SLAVE_SYSTEM_CONTROL) += spi-slave-system-control.o > + > +# SPI offload triggers > +obj-$(CONFIG_SPI_OFFLOAD_TRIGGER_PWM) += spi-offload-trigger-pwm.o > diff --git a/drivers/spi/spi-offload-trigger-pwm.c b/drivers/spi/spi-offload- > trigger-pwm.c > new file mode 100644 > index > 0000000000000000000000000000000000000000..b26d4437c589052709a8206f8314ffd08355 > 870e > --- /dev/null > +++ b/drivers/spi/spi-offload-trigger-pwm.c > @@ -0,0 +1,162 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * Copyright (C) 2024 Analog Devices Inc. > + * Copyright (C) 2024 BayLibre, SAS > + * > + * Generic PWM trigger for SPI offload. > + */ > + > +#include <linux/platform_device.h> > +#include <linux/pwm.h> > +#include <linux/mod_devicetable.h> > +#include <linux/spi/offload/provider.h> > +#include <linux/types.h> > + > +struct spi_offload_trigger_pwm_state { > + struct device *dev; > + struct pwm_device *pwm; > +}; > + > +static bool spi_offload_trigger_pwm_match(struct spi_offload_trigger > *trigger, > + enum spi_offload_trigger_type type, > + u64 *args, u32 nargs) > +{ > + if (nargs) > + return false; > + > + return type == SPI_OFFLOAD_TRIGGER_PERIODIC; > +} > + > +static int spi_offload_trigger_pwm_validate(struct spi_offload_trigger > *trigger, > + struct spi_offload_trigger_config > *config) > +{ > + struct spi_offload_trigger_pwm_state *st = > spi_offload_trigger_get_priv(trigger); > + struct spi_offload_trigger_periodic *periodic = &config->periodic; > + struct pwm_waveform wf = { }; > + int ret; > + > + if (config->type != SPI_OFFLOAD_TRIGGER_PERIODIC) > + return -EINVAL; > + > + if (!periodic->frequency_hz) > + return -EINVAL; > + > + wf.period_length_ns = DIV_ROUND_UP_ULL(NSEC_PER_SEC, periodic- > >frequency_hz); > + /* REVISIT: 50% duty-cycle for now - may add config parameter later > */ > + wf.duty_length_ns = wf.period_length_ns / 2; > + > + ret = pwm_round_waveform_might_sleep(st->pwm, &wf); > + if (ret < 0) > + return ret; > + > + periodic->frequency_hz = DIV_ROUND_UP_ULL(NSEC_PER_SEC, > wf.period_length_ns); > + > + return 0; > +} > + > +static int spi_offload_trigger_pwm_enable(struct spi_offload_trigger > *trigger, > + struct spi_offload_trigger_config > *config) > +{ > + struct spi_offload_trigger_pwm_state *st = > spi_offload_trigger_get_priv(trigger); > + struct spi_offload_trigger_periodic *periodic = &config->periodic; > + struct pwm_waveform wf = { }; > + > + if (config->type != SPI_OFFLOAD_TRIGGER_PERIODIC) > + return -EINVAL; > + > + if (!periodic->frequency_hz) > + return -EINVAL; > + > + wf.period_length_ns = DIV_ROUND_UP_ULL(NSEC_PER_SEC, periodic- > >frequency_hz); > + /* REVISIT: 50% duty-cycle for now - may add config parameter later > */ > + wf.duty_length_ns = wf.period_length_ns / 2; > + > + return pwm_set_waveform_might_sleep(st->pwm, &wf, false); > +} > + > +static void spi_offload_trigger_pwm_disable(struct spi_offload_trigger > *trigger) > +{ > + struct spi_offload_trigger_pwm_state *st = > spi_offload_trigger_get_priv(trigger); > + struct pwm_waveform wf; > + int ret; > + > + ret = pwm_get_waveform_might_sleep(st->pwm, &wf); > + if (ret < 0) { > + dev_err(st->dev, "failed to get waveform: %d\n", ret); > + return; > + } > + > + wf.duty_length_ns = 0; > + > + ret = pwm_set_waveform_might_sleep(st->pwm, &wf, false); > + if (ret < 0) > + dev_err(st->dev, "failed to disable PWM: %d\n", ret); > +} > + > +static const struct spi_offload_trigger_ops spi_offload_trigger_pwm_ops = { > + .match = spi_offload_trigger_pwm_match, > + .validate = spi_offload_trigger_pwm_validate, > + .enable = spi_offload_trigger_pwm_enable, > + .disable = spi_offload_trigger_pwm_disable, > +}; > + > +static void spi_offload_trigger_pwm_release(void *data) > +{ > + pwm_disable(data); > +} > + > +static int spi_offload_trigger_pwm_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct spi_offload_trigger_info info = { > + .fwnode = dev_fwnode(dev), > + .ops = &spi_offload_trigger_pwm_ops, > + }; > + struct spi_offload_trigger_pwm_state *st; > + struct pwm_state state; > + int ret; > + > + st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL); > + if (!st) > + return -ENOMEM; > + > + info.priv = st; > + st->dev = dev; > + > + st->pwm = devm_pwm_get(dev, NULL); > + if (IS_ERR(st->pwm)) > + return dev_err_probe(dev, PTR_ERR(st->pwm), "failed to get > PWM\n"); > + > + /* init with duty_cycle = 0, output enabled to ensure trigger off */ > + pwm_init_state(st->pwm, &state); > + state.enabled = true; > + > + ret = pwm_apply_might_sleep(st->pwm, &state); > + if (ret < 0) > + return dev_err_probe(dev, ret, "failed to apply PWM > state\n"); > + > + ret = devm_add_action_or_reset(dev, spi_offload_trigger_pwm_release, > st->pwm); > + if (ret) > + return ret; > + > + return devm_spi_offload_trigger_register(dev, &info); > +} > + > +static const struct of_device_id spi_offload_trigger_pwm_of_match_table[] = { > + { .compatible = "pwm-trigger" }, > + { } > +}; > +MODULE_DEVICE_TABLE(of, spi_offload_trigger_pwm_of_match_table); > + > +static struct platform_driver spi_offload_trigger_pwm_driver = { > + .driver = { > + .name = "pwm-trigger", > + .of_match_table = spi_offload_trigger_pwm_of_match_table, > + }, > + .probe = spi_offload_trigger_pwm_probe, > +}; > +module_platform_driver(spi_offload_trigger_pwm_driver); > + > +MODULE_AUTHOR("David Lechner <dlechner@baylibre.com>"); > +MODULE_DESCRIPTION("Generic PWM trigger"); > +MODULE_LICENSE("GPL"); >
diff --git a/MAINTAINERS b/MAINTAINERS index b2aa6f37743e48353c60e5973ea8126590c7f6d5..d8d72da5ac4bcab817a515774eb8db37a7e94f25 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -22131,6 +22131,7 @@ F: include/linux/mtd/spi-nor.h SPI OFFLOAD R: David Lechner <dlechner@baylibre.com> +F: drivers/spi/spi-offload-trigger-pwm.c F: drivers/spi/spi-offload.c F: include/linux/spi/spi-offload.h K: spi_offload diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index 02064a4e292815ec0213e2e446b4f90ed8855a52..2cfc14be869790f5226130428bb7cb40aadfb031 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -1320,4 +1320,16 @@ endif # SPI_SLAVE config SPI_DYNAMIC def_bool ACPI || OF_DYNAMIC || SPI_SLAVE +if SPI_OFFLOAD + +comment "SPI Offload triggers" + +config SPI_OFFLOAD_TRIGGER_PWM + tristate "SPI offload trigger using PWM" + depends on PWM + help + Generic SPI offload trigger implemented using PWM output. + +endif # SPI_OFFLOAD + endif # SPI diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile index bb5fc20df21332232533c2e70c0cc230f6bcf27f..0068d170bc99c750c13376c4013991d927bbac63 100644 --- a/drivers/spi/Makefile +++ b/drivers/spi/Makefile @@ -164,3 +164,6 @@ obj-$(CONFIG_SPI_AMD) += spi-amd.o # SPI slave protocol handlers obj-$(CONFIG_SPI_SLAVE_TIME) += spi-slave-time.o obj-$(CONFIG_SPI_SLAVE_SYSTEM_CONTROL) += spi-slave-system-control.o + +# SPI offload triggers +obj-$(CONFIG_SPI_OFFLOAD_TRIGGER_PWM) += spi-offload-trigger-pwm.o diff --git a/drivers/spi/spi-offload-trigger-pwm.c b/drivers/spi/spi-offload-trigger-pwm.c new file mode 100644 index 0000000000000000000000000000000000000000..b26d4437c589052709a8206f8314ffd08355870e --- /dev/null +++ b/drivers/spi/spi-offload-trigger-pwm.c @@ -0,0 +1,162 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2024 Analog Devices Inc. + * Copyright (C) 2024 BayLibre, SAS + * + * Generic PWM trigger for SPI offload. + */ + +#include <linux/platform_device.h> +#include <linux/pwm.h> +#include <linux/mod_devicetable.h> +#include <linux/spi/offload/provider.h> +#include <linux/types.h> + +struct spi_offload_trigger_pwm_state { + struct device *dev; + struct pwm_device *pwm; +}; + +static bool spi_offload_trigger_pwm_match(struct spi_offload_trigger *trigger, + enum spi_offload_trigger_type type, + u64 *args, u32 nargs) +{ + if (nargs) + return false; + + return type == SPI_OFFLOAD_TRIGGER_PERIODIC; +} + +static int spi_offload_trigger_pwm_validate(struct spi_offload_trigger *trigger, + struct spi_offload_trigger_config *config) +{ + struct spi_offload_trigger_pwm_state *st = spi_offload_trigger_get_priv(trigger); + struct spi_offload_trigger_periodic *periodic = &config->periodic; + struct pwm_waveform wf = { }; + int ret; + + if (config->type != SPI_OFFLOAD_TRIGGER_PERIODIC) + return -EINVAL; + + if (!periodic->frequency_hz) + return -EINVAL; + + wf.period_length_ns = DIV_ROUND_UP_ULL(NSEC_PER_SEC, periodic->frequency_hz); + /* REVISIT: 50% duty-cycle for now - may add config parameter later */ + wf.duty_length_ns = wf.period_length_ns / 2; + + ret = pwm_round_waveform_might_sleep(st->pwm, &wf); + if (ret < 0) + return ret; + + periodic->frequency_hz = DIV_ROUND_UP_ULL(NSEC_PER_SEC, wf.period_length_ns); + + return 0; +} + +static int spi_offload_trigger_pwm_enable(struct spi_offload_trigger *trigger, + struct spi_offload_trigger_config *config) +{ + struct spi_offload_trigger_pwm_state *st = spi_offload_trigger_get_priv(trigger); + struct spi_offload_trigger_periodic *periodic = &config->periodic; + struct pwm_waveform wf = { }; + + if (config->type != SPI_OFFLOAD_TRIGGER_PERIODIC) + return -EINVAL; + + if (!periodic->frequency_hz) + return -EINVAL; + + wf.period_length_ns = DIV_ROUND_UP_ULL(NSEC_PER_SEC, periodic->frequency_hz); + /* REVISIT: 50% duty-cycle for now - may add config parameter later */ + wf.duty_length_ns = wf.period_length_ns / 2; + + return pwm_set_waveform_might_sleep(st->pwm, &wf, false); +} + +static void spi_offload_trigger_pwm_disable(struct spi_offload_trigger *trigger) +{ + struct spi_offload_trigger_pwm_state *st = spi_offload_trigger_get_priv(trigger); + struct pwm_waveform wf; + int ret; + + ret = pwm_get_waveform_might_sleep(st->pwm, &wf); + if (ret < 0) { + dev_err(st->dev, "failed to get waveform: %d\n", ret); + return; + } + + wf.duty_length_ns = 0; + + ret = pwm_set_waveform_might_sleep(st->pwm, &wf, false); + if (ret < 0) + dev_err(st->dev, "failed to disable PWM: %d\n", ret); +} + +static const struct spi_offload_trigger_ops spi_offload_trigger_pwm_ops = { + .match = spi_offload_trigger_pwm_match, + .validate = spi_offload_trigger_pwm_validate, + .enable = spi_offload_trigger_pwm_enable, + .disable = spi_offload_trigger_pwm_disable, +}; + +static void spi_offload_trigger_pwm_release(void *data) +{ + pwm_disable(data); +} + +static int spi_offload_trigger_pwm_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct spi_offload_trigger_info info = { + .fwnode = dev_fwnode(dev), + .ops = &spi_offload_trigger_pwm_ops, + }; + struct spi_offload_trigger_pwm_state *st; + struct pwm_state state; + int ret; + + st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL); + if (!st) + return -ENOMEM; + + info.priv = st; + st->dev = dev; + + st->pwm = devm_pwm_get(dev, NULL); + if (IS_ERR(st->pwm)) + return dev_err_probe(dev, PTR_ERR(st->pwm), "failed to get PWM\n"); + + /* init with duty_cycle = 0, output enabled to ensure trigger off */ + pwm_init_state(st->pwm, &state); + state.enabled = true; + + ret = pwm_apply_might_sleep(st->pwm, &state); + if (ret < 0) + return dev_err_probe(dev, ret, "failed to apply PWM state\n"); + + ret = devm_add_action_or_reset(dev, spi_offload_trigger_pwm_release, st->pwm); + if (ret) + return ret; + + return devm_spi_offload_trigger_register(dev, &info); +} + +static const struct of_device_id spi_offload_trigger_pwm_of_match_table[] = { + { .compatible = "pwm-trigger" }, + { } +}; +MODULE_DEVICE_TABLE(of, spi_offload_trigger_pwm_of_match_table); + +static struct platform_driver spi_offload_trigger_pwm_driver = { + .driver = { + .name = "pwm-trigger", + .of_match_table = spi_offload_trigger_pwm_of_match_table, + }, + .probe = spi_offload_trigger_pwm_probe, +}; +module_platform_driver(spi_offload_trigger_pwm_driver); + +MODULE_AUTHOR("David Lechner <dlechner@baylibre.com>"); +MODULE_DESCRIPTION("Generic PWM trigger"); +MODULE_LICENSE("GPL");