Adds the Apple PWM controller driver. Signed-off-by: Sasha Finkelstein <fnkl.kernel@xxxxxxxxx> Acked-by: Sven Peter <sven@xxxxxxxxxxxxx> --- drivers/pwm/Kconfig | 12 ++++ drivers/pwm/Makefile | 1 + drivers/pwm/pwm-apple.c | 127 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 140 insertions(+) create mode 100644 drivers/pwm/pwm-apple.c diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig index 60d13a949bc5..c3be11468414 100644 --- a/drivers/pwm/Kconfig +++ b/drivers/pwm/Kconfig @@ -51,6 +51,18 @@ config PWM_AB8500 To compile this driver as a module, choose M here: the module will be called pwm-ab8500. +config PWM_APPLE + tristate "Apple SoC PWM support" + depends on ARCH_APPLE || COMPILE_TEST + help + Generic PWM framework driver for PWM controller present on + Apple SoCs + + Say Y here if you have an ARM Apple laptop, otherwise say N + + To compile this driver as a module, choose M here: the module + will be called pwm-apple. + config PWM_ATMEL tristate "Atmel PWM support" depends on ARCH_AT91 || COMPILE_TEST diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile index 7bf1a29f02b8..19899b912e00 100644 --- a/drivers/pwm/Makefile +++ b/drivers/pwm/Makefile @@ -2,6 +2,7 @@ obj-$(CONFIG_PWM) += core.o obj-$(CONFIG_PWM_SYSFS) += sysfs.o obj-$(CONFIG_PWM_AB8500) += pwm-ab8500.o +obj-$(CONFIG_PWM_APPLE) += pwm-apple.o obj-$(CONFIG_PWM_ATMEL) += pwm-atmel.o obj-$(CONFIG_PWM_ATMEL_HLCDC_PWM) += pwm-atmel-hlcdc.o obj-$(CONFIG_PWM_ATMEL_TCB) += pwm-atmel-tcb.o diff --git a/drivers/pwm/pwm-apple.c b/drivers/pwm/pwm-apple.c new file mode 100644 index 000000000000..b0c3f86fd578 --- /dev/null +++ b/drivers/pwm/pwm-apple.c @@ -0,0 +1,127 @@ +// SPDX-License-Identifier: GPL-2.0 OR MIT +/* + * Driver for the Apple SoC PWM controller + * + * Copyright The Asahi Linux Contributors + */ + +#include <linux/clk.h> +#include <linux/io.h> +#include <linux/math64.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> +#include <linux/pm_runtime.h> +#include <linux/pwm.h> + +#define PWM_CONTROL 0x00 +#define PWM_ON_CYCLES 0x1c +#define PWM_OFF_CYCLES 0x18 + +#define CTRL_ENABLE BIT(0) +#define CTRL_MODE BIT(2) +#define CTRL_UPDATE BIT(5) +#define CTRL_TRIGGER BIT(9) +#define CTRL_INVERT BIT(10) +#define CTRL_OUTPUT_ENABLE BIT(14) + +struct apple_pwm { + struct pwm_chip chip; + void __iomem *base; + u64 clkrate; +}; + +static int apple_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, + const struct pwm_state *state) +{ + struct apple_pwm *fpwm; + u64 on_cycles, off_cycles; + + fpwm = container_of(chip, struct apple_pwm, chip); + if (state->enabled) { + on_cycles = mul_u64_u64_div_u64(fpwm->clkrate, + state->duty_cycle, NSEC_PER_SEC); + off_cycles = mul_u64_u64_div_u64(fpwm->clkrate, + state->period, NSEC_PER_SEC) - on_cycles; + writel(on_cycles, fpwm->base + PWM_ON_CYCLES); + writel(off_cycles, fpwm->base + PWM_OFF_CYCLES); + writel(CTRL_ENABLE | CTRL_OUTPUT_ENABLE | CTRL_UPDATE, + fpwm->base + PWM_CONTROL); + } else { + writel(0, fpwm->base + PWM_CONTROL); + } + return 0; +} + +static void apple_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm, + struct pwm_state *state) +{ + struct apple_pwm *fpwm; + u32 on_cycles, off_cycles, ctrl; + + fpwm = container_of(chip, struct apple_pwm, chip); + + ctrl = readl(fpwm->base + PWM_CONTROL); + on_cycles = readl(fpwm->base + PWM_ON_CYCLES); + off_cycles = readl(fpwm->base + PWM_OFF_CYCLES); + + state->enabled = (ctrl & CTRL_ENABLE) && (ctrl & CTRL_OUTPUT_ENABLE); + state->polarity = PWM_POLARITY_NORMAL; + state->duty_cycle = div_u64(on_cycles, fpwm->clkrate) * NSEC_PER_SEC; + state->period = div_u64(off_cycles + on_cycles, fpwm->clkrate) * NSEC_PER_SEC; +} + +static const struct pwm_ops apple_pwm_ops = { + .apply = apple_pwm_apply, + .get_state = apple_pwm_get_state, + .owner = THIS_MODULE, +}; + +static int apple_pwm_probe(struct platform_device *pdev) +{ + struct apple_pwm *pwm; + struct clk *clk; + int ret; + + pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL); + if (!pwm) + return -ENOMEM; + + pwm->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(pwm->base)) + return PTR_ERR(pwm->base); + + platform_set_drvdata(pdev, pwm); + + clk = devm_clk_get_enabled(&pdev->dev, NULL); + if (IS_ERR(clk)) + return PTR_ERR(clk); + + pwm->clkrate = clk_get_rate(clk); + pwm->chip.dev = &pdev->dev; + pwm->chip.npwm = 1; + pwm->chip.ops = &apple_pwm_ops; + + ret = devm_pwmchip_add(&pdev->dev, &pwm->chip); + return ret; +} + +static const struct of_device_id apple_pwm_of_match[] = { + { .compatible = "apple,s5l-fpwm" }, + {} +}; +MODULE_DEVICE_TABLE(of, apple_pwm_of_match); + +static struct platform_driver apple_pwm_driver = { + .probe = apple_pwm_probe, + .driver = { + .name = "apple-pwm", + .owner = THIS_MODULE, + .of_match_table = apple_pwm_of_match, + }, +}; +module_platform_driver(apple_pwm_driver); + +MODULE_DESCRIPTION("Apple SoC PWM driver"); +MODULE_LICENSE("Dual MIT/GPL"); -- 2.38.1