| Message ID | 20210312122454.24480-12-nsaenzjulienne@suse.de (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
| Series | Raspberry Pi PoE HAT fan support | expand |
Hello Nicolas, On Fri, Mar 12, 2021 at 01:24:54PM +0100, Nicolas Saenz Julienne wrote: > Adds support to control the PWM bus available in official Raspberry Pi > PoE HAT. Only RPi's co-processor has access to it, so commands have to > be sent through RPi's firmware mailbox interface. > > Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> > > --- > > Changes since v7: > - Remove unwarranted RPI_PWM_DEF_DUTY_REG usage > > Changes since v6: > - Use %pe > - Round divisions properly > - Use dev_err_probe() > - Pass check_patch > > Changes since v3: > - Rename compatible string to be more explicit WRT to bus's limitations > > Changes since v2: > - Use devm_rpi_firmware_get() > - Rename driver > - Small cleanups > > Changes since v1: > - Use default pwm bindings and get rid of xlate() function > - Correct spelling errors > - Correct apply() function > - Round values > - Fix divisions in arm32 mode > - Small cleanups > > drivers/pwm/Kconfig | 9 ++ > drivers/pwm/Makefile | 1 + > drivers/pwm/pwm-raspberrypi-poe.c | 206 ++++++++++++++++++++++++++++++ > 3 files changed, 216 insertions(+) > create mode 100644 drivers/pwm/pwm-raspberrypi-poe.c > > diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig > index a7a7a9f26aef..d3371ac7b871 100644 > --- a/drivers/pwm/Kconfig > +++ b/drivers/pwm/Kconfig > @@ -431,6 +431,15 @@ config PWM_PXA > To compile this driver as a module, choose M here: the module > will be called pwm-pxa. > > +config PWM_RASPBERRYPI_POE > + tristate "Raspberry Pi Firwmware PoE Hat PWM support" > + # Make sure not 'y' when RASPBERRYPI_FIRMWARE is 'm'. This can only > + # happen when COMPILE_TEST=y, hence the added !RASPBERRYPI_FIRMWARE. > + depends on RASPBERRYPI_FIRMWARE || (COMPILE_TEST && !RASPBERRYPI_FIRMWARE) > + help > + Enable Raspberry Pi firmware controller PWM bus used to control the > + official RPI PoE hat > + > config PWM_RCAR > tristate "Renesas R-Car PWM support" > depends on ARCH_RENESAS || COMPILE_TEST > diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile > index 4e35a55fa7b6..d3879619bd76 100644 > --- a/drivers/pwm/Makefile > +++ b/drivers/pwm/Makefile > @@ -39,6 +39,7 @@ obj-$(CONFIG_PWM_NTXEC) += pwm-ntxec.o > obj-$(CONFIG_PWM_OMAP_DMTIMER) += pwm-omap-dmtimer.o > obj-$(CONFIG_PWM_PCA9685) += pwm-pca9685.o > obj-$(CONFIG_PWM_PXA) += pwm-pxa.o > +obj-$(CONFIG_PWM_RASPBERRYPI_POE) += pwm-raspberrypi-poe.o > obj-$(CONFIG_PWM_RCAR) += pwm-rcar.o > obj-$(CONFIG_PWM_RENESAS_TPU) += pwm-renesas-tpu.o > obj-$(CONFIG_PWM_ROCKCHIP) += pwm-rockchip.o > diff --git a/drivers/pwm/pwm-raspberrypi-poe.c b/drivers/pwm/pwm-raspberrypi-poe.c > new file mode 100644 > index 000000000000..71ade5e55069 > --- /dev/null > +++ b/drivers/pwm/pwm-raspberrypi-poe.c > @@ -0,0 +1,206 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright 2020 Nicolas Saenz Julienne <nsaenzjulienne@suse.de> 2021? > + * For more information on Raspberry Pi's PoE hat see: > + * https://www.raspberrypi.org/products/poe-hat/ Out of personal interest: Is this hat also able to power a RPi CM4? > + * Limitations: > + * - No disable bit, so a disabled PWM is simulated by duty_cycle 0 > + * - Only normal polarity > + * - Fixed 12.5 kHz period > + * > + * The current period is completed when HW is reconfigured. > + */ Other than that as mentioned in the previous round: This looks good, Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> What is your thought about how to get this series merged? At least input, staging, armsoc, clk, reset anf firmware are touched. Do you prepare a branch for merging in the relevant trees (once you have all the necessary Acks)? Best regards Uwe
Hi Uwe, On Fri, 2021-03-12 at 21:12 +0100, Uwe Kleine-König wrote: > Hello Nicolas, > > +// SPDX-License-Identifier: GPL-2.0 > > +/* > > + * Copyright 2020 Nicolas Saenz Julienne <nsaenzjulienne@suse.de> > > 2021? Yes. > > + * For more information on Raspberry Pi's PoE hat see: > > + * https://www.raspberrypi.org/products/poe-hat/ > > Out of personal interest: Is this hat also able to power a RPi CM4? I haven't tested it, and can't at the moment (no PoE injector available). But the physical pin layout, and routing in CM4's IO board fits the hat. So I'd say yes. > > + * Limitations: > > + * - No disable bit, so a disabled PWM is simulated by duty_cycle 0 > > + * - Only normal polarity > > + * - Fixed 12.5 kHz period > > + * > > + * The current period is completed when HW is reconfigured. > > + */ > > Other than that as mentioned in the previous round: This looks good, > > Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Thanks! > What is your thought about how to get this series merged? > At least input, staging, armsoc, clk, reset anf firmware are touched. Do you > prepare a branch for merging in the relevant trees (once you have all the > necessary Acks)? As per Linusw suggestion I'll send a pull request myself into the SoC tree and hope for the best. :) Regards, Nicolas
On Fri, Mar 12, 2021 at 01:24:54PM +0100, Nicolas Saenz Julienne wrote: > Adds support to control the PWM bus available in official Raspberry Pi > PoE HAT. Only RPi's co-processor has access to it, so commands have to > be sent through RPi's firmware mailbox interface. > > Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> > > --- > > Changes since v7: > - Remove unwarranted RPI_PWM_DEF_DUTY_REG usage > > Changes since v6: > - Use %pe > - Round divisions properly > - Use dev_err_probe() > - Pass check_patch > > Changes since v3: > - Rename compatible string to be more explicit WRT to bus's limitations > > Changes since v2: > - Use devm_rpi_firmware_get() > - Rename driver > - Small cleanups > > Changes since v1: > - Use default pwm bindings and get rid of xlate() function > - Correct spelling errors > - Correct apply() function > - Round values > - Fix divisions in arm32 mode > - Small cleanups > > drivers/pwm/Kconfig | 9 ++ > drivers/pwm/Makefile | 1 + > drivers/pwm/pwm-raspberrypi-poe.c | 206 ++++++++++++++++++++++++++++++ > 3 files changed, 216 insertions(+) > create mode 100644 drivers/pwm/pwm-raspberrypi-poe.c Acked-by: Thierry Reding <thierry.reding@gmail.com>
diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig index a7a7a9f26aef..d3371ac7b871 100644 --- a/drivers/pwm/Kconfig +++ b/drivers/pwm/Kconfig @@ -431,6 +431,15 @@ config PWM_PXA To compile this driver as a module, choose M here: the module will be called pwm-pxa. +config PWM_RASPBERRYPI_POE + tristate "Raspberry Pi Firwmware PoE Hat PWM support" + # Make sure not 'y' when RASPBERRYPI_FIRMWARE is 'm'. This can only + # happen when COMPILE_TEST=y, hence the added !RASPBERRYPI_FIRMWARE. + depends on RASPBERRYPI_FIRMWARE || (COMPILE_TEST && !RASPBERRYPI_FIRMWARE) + help + Enable Raspberry Pi firmware controller PWM bus used to control the + official RPI PoE hat + config PWM_RCAR tristate "Renesas R-Car PWM support" depends on ARCH_RENESAS || COMPILE_TEST diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile index 4e35a55fa7b6..d3879619bd76 100644 --- a/drivers/pwm/Makefile +++ b/drivers/pwm/Makefile @@ -39,6 +39,7 @@ obj-$(CONFIG_PWM_NTXEC) += pwm-ntxec.o obj-$(CONFIG_PWM_OMAP_DMTIMER) += pwm-omap-dmtimer.o obj-$(CONFIG_PWM_PCA9685) += pwm-pca9685.o obj-$(CONFIG_PWM_PXA) += pwm-pxa.o +obj-$(CONFIG_PWM_RASPBERRYPI_POE) += pwm-raspberrypi-poe.o obj-$(CONFIG_PWM_RCAR) += pwm-rcar.o obj-$(CONFIG_PWM_RENESAS_TPU) += pwm-renesas-tpu.o obj-$(CONFIG_PWM_ROCKCHIP) += pwm-rockchip.o diff --git a/drivers/pwm/pwm-raspberrypi-poe.c b/drivers/pwm/pwm-raspberrypi-poe.c new file mode 100644 index 000000000000..71ade5e55069 --- /dev/null +++ b/drivers/pwm/pwm-raspberrypi-poe.c @@ -0,0 +1,206 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright 2020 Nicolas Saenz Julienne <nsaenzjulienne@suse.de> + * For more information on Raspberry Pi's PoE hat see: + * https://www.raspberrypi.org/products/poe-hat/ + * + * Limitations: + * - No disable bit, so a disabled PWM is simulated by duty_cycle 0 + * - Only normal polarity + * - Fixed 12.5 kHz period + * + * The current period is completed when HW is reconfigured. + */ + +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/pwm.h> + +#include <soc/bcm2835/raspberrypi-firmware.h> +#include <dt-bindings/pwm/raspberrypi,firmware-poe-pwm.h> + +#define RPI_PWM_MAX_DUTY 255 +#define RPI_PWM_PERIOD_NS 80000 /* 12.5 kHz */ + +#define RPI_PWM_CUR_DUTY_REG 0x0 + +struct raspberrypi_pwm { + struct rpi_firmware *firmware; + struct pwm_chip chip; + unsigned int duty_cycle; +}; + +struct raspberrypi_pwm_prop { + __le32 reg; + __le32 val; + __le32 ret; +} __packed; + +static inline +struct raspberrypi_pwm *raspberrypi_pwm_from_chip(struct pwm_chip *chip) +{ + return container_of(chip, struct raspberrypi_pwm, chip); +} + +static int raspberrypi_pwm_set_property(struct rpi_firmware *firmware, + u32 reg, u32 val) +{ + struct raspberrypi_pwm_prop msg = { + .reg = cpu_to_le32(reg), + .val = cpu_to_le32(val), + }; + int ret; + + ret = rpi_firmware_property(firmware, RPI_FIRMWARE_SET_POE_HAT_VAL, + &msg, sizeof(msg)); + if (ret) + return ret; + if (msg.ret) + return -EIO; + + return 0; +} + +static int raspberrypi_pwm_get_property(struct rpi_firmware *firmware, + u32 reg, u32 *val) +{ + struct raspberrypi_pwm_prop msg = { + .reg = reg + }; + int ret; + + ret = rpi_firmware_property(firmware, RPI_FIRMWARE_GET_POE_HAT_VAL, + &msg, sizeof(msg)); + if (ret) + return ret; + if (msg.ret) + return -EIO; + + *val = le32_to_cpu(msg.val); + + return 0; +} + +static void raspberrypi_pwm_get_state(struct pwm_chip *chip, + struct pwm_device *pwm, + struct pwm_state *state) +{ + struct raspberrypi_pwm *rpipwm = raspberrypi_pwm_from_chip(chip); + + state->period = RPI_PWM_PERIOD_NS; + state->duty_cycle = DIV_ROUND_UP(rpipwm->duty_cycle * RPI_PWM_PERIOD_NS, + RPI_PWM_MAX_DUTY); + state->enabled = !!(rpipwm->duty_cycle); + state->polarity = PWM_POLARITY_NORMAL; +} + +static int raspberrypi_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, + const struct pwm_state *state) +{ + struct raspberrypi_pwm *rpipwm = raspberrypi_pwm_from_chip(chip); + unsigned int duty_cycle; + int ret; + + if (state->period < RPI_PWM_PERIOD_NS || + state->polarity != PWM_POLARITY_NORMAL) + return -EINVAL; + + if (!state->enabled) + duty_cycle = 0; + else if (state->duty_cycle < RPI_PWM_PERIOD_NS) + duty_cycle = DIV_ROUND_DOWN_ULL(state->duty_cycle * RPI_PWM_MAX_DUTY, + RPI_PWM_PERIOD_NS); + else + duty_cycle = RPI_PWM_MAX_DUTY; + + if (duty_cycle == rpipwm->duty_cycle) + return 0; + + ret = raspberrypi_pwm_set_property(rpipwm->firmware, RPI_PWM_CUR_DUTY_REG, + duty_cycle); + if (ret) { + dev_err(chip->dev, "Failed to set duty cycle: %pe\n", + ERR_PTR(ret)); + return ret; + } + + rpipwm->duty_cycle = duty_cycle; + + return 0; +} + +static const struct pwm_ops raspberrypi_pwm_ops = { + .get_state = raspberrypi_pwm_get_state, + .apply = raspberrypi_pwm_apply, + .owner = THIS_MODULE, +}; + +static int raspberrypi_pwm_probe(struct platform_device *pdev) +{ + struct device_node *firmware_node; + struct device *dev = &pdev->dev; + struct rpi_firmware *firmware; + struct raspberrypi_pwm *rpipwm; + int ret; + + firmware_node = of_get_parent(dev->of_node); + if (!firmware_node) { + dev_err(dev, "Missing firmware node\n"); + return -ENOENT; + } + + firmware = devm_rpi_firmware_get(&pdev->dev, firmware_node); + of_node_put(firmware_node); + if (!firmware) + return dev_err_probe(dev, -EPROBE_DEFER, + "Failed to get firmware handle\n"); + + rpipwm = devm_kzalloc(&pdev->dev, sizeof(*rpipwm), GFP_KERNEL); + if (!rpipwm) + return -ENOMEM; + + rpipwm->firmware = firmware; + rpipwm->chip.dev = dev; + rpipwm->chip.ops = &raspberrypi_pwm_ops; + rpipwm->chip.base = -1; + rpipwm->chip.npwm = RASPBERRYPI_FIRMWARE_PWM_NUM; + + platform_set_drvdata(pdev, rpipwm); + + ret = raspberrypi_pwm_get_property(rpipwm->firmware, RPI_PWM_CUR_DUTY_REG, + &rpipwm->duty_cycle); + if (ret) { + dev_err(dev, "Failed to get duty cycle: %pe\n", ERR_PTR(ret)); + return ret; + } + + return pwmchip_add(&rpipwm->chip); +} + +static int raspberrypi_pwm_remove(struct platform_device *pdev) +{ + struct raspberrypi_pwm *rpipwm = platform_get_drvdata(pdev); + + return pwmchip_remove(&rpipwm->chip); +} + +static const struct of_device_id raspberrypi_pwm_of_match[] = { + { .compatible = "raspberrypi,firmware-poe-pwm", }, + { } +}; +MODULE_DEVICE_TABLE(of, raspberrypi_pwm_of_match); + +static struct platform_driver raspberrypi_pwm_driver = { + .driver = { + .name = "raspberrypi-poe-pwm", + .of_match_table = raspberrypi_pwm_of_match, + }, + .probe = raspberrypi_pwm_probe, + .remove = raspberrypi_pwm_remove, +}; +module_platform_driver(raspberrypi_pwm_driver); + +MODULE_AUTHOR("Nicolas Saenz Julienne <nsaenzjulienne@suse.de>"); +MODULE_DESCRIPTION("Raspberry Pi Firmware Based PWM Bus Driver"); +MODULE_LICENSE("GPL v2");
Adds support to control the PWM bus available in official Raspberry Pi PoE HAT. Only RPi's co-processor has access to it, so commands have to be sent through RPi's firmware mailbox interface. Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> --- Changes since v7: - Remove unwarranted RPI_PWM_DEF_DUTY_REG usage Changes since v6: - Use %pe - Round divisions properly - Use dev_err_probe() - Pass check_patch Changes since v3: - Rename compatible string to be more explicit WRT to bus's limitations Changes since v2: - Use devm_rpi_firmware_get() - Rename driver - Small cleanups Changes since v1: - Use default pwm bindings and get rid of xlate() function - Correct spelling errors - Correct apply() function - Round values - Fix divisions in arm32 mode - Small cleanups drivers/pwm/Kconfig | 9 ++ drivers/pwm/Makefile | 1 + drivers/pwm/pwm-raspberrypi-poe.c | 206 ++++++++++++++++++++++++++++++ 3 files changed, 216 insertions(+) create mode 100644 drivers/pwm/pwm-raspberrypi-poe.c