From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- drivers/pwm/pwm-berlin.c | 330 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 330 insertions(+) create mode 100644 drivers/pwm/pwm-berlin.c (limited to 'drivers/pwm/pwm-berlin.c') diff --git a/drivers/pwm/pwm-berlin.c b/drivers/pwm/pwm-berlin.c new file mode 100644 index 000000000..0971c666a --- /dev/null +++ b/drivers/pwm/pwm-berlin.c @@ -0,0 +1,330 @@ +/* + * Marvell Berlin PWM driver + * + * Copyright (C) 2015 Marvell Technology Group Ltd. + * + * Author: Antoine Tenart + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#define BERLIN_PWM_EN 0x0 +#define BERLIN_PWM_ENABLE BIT(0) +#define BERLIN_PWM_CONTROL 0x4 +/* + * The prescaler claims to support 8 different moduli, configured using the + * low three bits of PWM_CONTROL. (Sequentially, they are 1, 4, 8, 16, 64, + * 256, 1024, and 4096.) However, the moduli from 4 to 1024 appear to be + * implemented by internally shifting TCNT left without adding additional + * bits. So, the max TCNT that actually works for a modulus of 4 is 0x3fff; + * for 8, 0x1fff; and so on. This means that those moduli are entirely + * useless, as we could just do the shift ourselves. The 4096 modulus is + * implemented with a real prescaler, so we do use that, but we treat it + * as a flag instead of pretending the modulus is actually configurable. + */ +#define BERLIN_PWM_PRESCALE_4096 0x7 +#define BERLIN_PWM_INVERT_POLARITY BIT(3) +#define BERLIN_PWM_DUTY 0x8 +#define BERLIN_PWM_TCNT 0xc +#define BERLIN_PWM_MAX_TCNT 65535 + +struct berlin_pwm_channel { + u32 enable; + u32 ctrl; + u32 duty; + u32 tcnt; +}; + +struct berlin_pwm_chip { + struct pwm_chip chip; + struct clk *clk; + void __iomem *base; +}; + +static inline struct berlin_pwm_chip *to_berlin_pwm_chip(struct pwm_chip *chip) +{ + return container_of(chip, struct berlin_pwm_chip, chip); +} + +static inline u32 berlin_pwm_readl(struct berlin_pwm_chip *bpc, + unsigned int channel, unsigned long offset) +{ + return readl_relaxed(bpc->base + channel * 0x10 + offset); +} + +static inline void berlin_pwm_writel(struct berlin_pwm_chip *bpc, + unsigned int channel, u32 value, + unsigned long offset) +{ + writel_relaxed(value, bpc->base + channel * 0x10 + offset); +} + +static int berlin_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct berlin_pwm_channel *channel; + + channel = kzalloc(sizeof(*channel), GFP_KERNEL); + if (!channel) + return -ENOMEM; + + return pwm_set_chip_data(pwm, channel); +} + +static void berlin_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct berlin_pwm_channel *channel = pwm_get_chip_data(pwm); + + kfree(channel); +} + +static int berlin_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, + u64 duty_ns, u64 period_ns) +{ + struct berlin_pwm_chip *bpc = to_berlin_pwm_chip(chip); + bool prescale_4096 = false; + u32 value, duty, period; + u64 cycles; + + cycles = clk_get_rate(bpc->clk); + cycles *= period_ns; + do_div(cycles, NSEC_PER_SEC); + + if (cycles > BERLIN_PWM_MAX_TCNT) { + prescale_4096 = true; + cycles >>= 12; // Prescaled by 4096 + + if (cycles > BERLIN_PWM_MAX_TCNT) + return -ERANGE; + } + + period = cycles; + cycles *= duty_ns; + do_div(cycles, period_ns); + duty = cycles; + + value = berlin_pwm_readl(bpc, pwm->hwpwm, BERLIN_PWM_CONTROL); + if (prescale_4096) + value |= BERLIN_PWM_PRESCALE_4096; + else + value &= ~BERLIN_PWM_PRESCALE_4096; + berlin_pwm_writel(bpc, pwm->hwpwm, value, BERLIN_PWM_CONTROL); + + berlin_pwm_writel(bpc, pwm->hwpwm, duty, BERLIN_PWM_DUTY); + berlin_pwm_writel(bpc, pwm->hwpwm, period, BERLIN_PWM_TCNT); + + return 0; +} + +static int berlin_pwm_set_polarity(struct pwm_chip *chip, + struct pwm_device *pwm, + enum pwm_polarity polarity) +{ + struct berlin_pwm_chip *bpc = to_berlin_pwm_chip(chip); + u32 value; + + value = berlin_pwm_readl(bpc, pwm->hwpwm, BERLIN_PWM_CONTROL); + + if (polarity == PWM_POLARITY_NORMAL) + value &= ~BERLIN_PWM_INVERT_POLARITY; + else + value |= BERLIN_PWM_INVERT_POLARITY; + + berlin_pwm_writel(bpc, pwm->hwpwm, value, BERLIN_PWM_CONTROL); + + return 0; +} + +static int berlin_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct berlin_pwm_chip *bpc = to_berlin_pwm_chip(chip); + u32 value; + + value = berlin_pwm_readl(bpc, pwm->hwpwm, BERLIN_PWM_EN); + value |= BERLIN_PWM_ENABLE; + berlin_pwm_writel(bpc, pwm->hwpwm, value, BERLIN_PWM_EN); + + return 0; +} + +static void berlin_pwm_disable(struct pwm_chip *chip, + struct pwm_device *pwm) +{ + struct berlin_pwm_chip *bpc = to_berlin_pwm_chip(chip); + u32 value; + + value = berlin_pwm_readl(bpc, pwm->hwpwm, BERLIN_PWM_EN); + value &= ~BERLIN_PWM_ENABLE; + berlin_pwm_writel(bpc, pwm->hwpwm, value, BERLIN_PWM_EN); +} + +static int berlin_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, + const struct pwm_state *state) +{ + int err; + bool enabled = pwm->state.enabled; + + if (state->polarity != pwm->state.polarity) { + if (enabled) { + berlin_pwm_disable(chip, pwm); + enabled = false; + } + + err = berlin_pwm_set_polarity(chip, pwm, state->polarity); + if (err) + return err; + } + + if (!state->enabled) { + if (enabled) + berlin_pwm_disable(chip, pwm); + return 0; + } + + err = berlin_pwm_config(chip, pwm, state->duty_cycle, state->period); + if (err) + return err; + + if (!enabled) + return berlin_pwm_enable(chip, pwm); + + return 0; +} + +static const struct pwm_ops berlin_pwm_ops = { + .request = berlin_pwm_request, + .free = berlin_pwm_free, + .apply = berlin_pwm_apply, + .owner = THIS_MODULE, +}; + +static const struct of_device_id berlin_pwm_match[] = { + { .compatible = "marvell,berlin-pwm" }, + { }, +}; +MODULE_DEVICE_TABLE(of, berlin_pwm_match); + +static int berlin_pwm_probe(struct platform_device *pdev) +{ + struct berlin_pwm_chip *bpc; + int ret; + + bpc = devm_kzalloc(&pdev->dev, sizeof(*bpc), GFP_KERNEL); + if (!bpc) + return -ENOMEM; + + bpc->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(bpc->base)) + return PTR_ERR(bpc->base); + + bpc->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(bpc->clk)) + return PTR_ERR(bpc->clk); + + ret = clk_prepare_enable(bpc->clk); + if (ret) + return ret; + + bpc->chip.dev = &pdev->dev; + bpc->chip.ops = &berlin_pwm_ops; + bpc->chip.npwm = 4; + + ret = pwmchip_add(&bpc->chip); + if (ret < 0) { + dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret); + clk_disable_unprepare(bpc->clk); + return ret; + } + + platform_set_drvdata(pdev, bpc); + + return 0; +} + +static void berlin_pwm_remove(struct platform_device *pdev) +{ + struct berlin_pwm_chip *bpc = platform_get_drvdata(pdev); + + pwmchip_remove(&bpc->chip); + + clk_disable_unprepare(bpc->clk); +} + +#ifdef CONFIG_PM_SLEEP +static int berlin_pwm_suspend(struct device *dev) +{ + struct berlin_pwm_chip *bpc = dev_get_drvdata(dev); + unsigned int i; + + for (i = 0; i < bpc->chip.npwm; i++) { + struct berlin_pwm_channel *channel; + + channel = pwm_get_chip_data(&bpc->chip.pwms[i]); + if (!channel) + continue; + + channel->enable = berlin_pwm_readl(bpc, i, BERLIN_PWM_ENABLE); + channel->ctrl = berlin_pwm_readl(bpc, i, BERLIN_PWM_CONTROL); + channel->duty = berlin_pwm_readl(bpc, i, BERLIN_PWM_DUTY); + channel->tcnt = berlin_pwm_readl(bpc, i, BERLIN_PWM_TCNT); + } + + clk_disable_unprepare(bpc->clk); + + return 0; +} + +static int berlin_pwm_resume(struct device *dev) +{ + struct berlin_pwm_chip *bpc = dev_get_drvdata(dev); + unsigned int i; + int ret; + + ret = clk_prepare_enable(bpc->clk); + if (ret) + return ret; + + for (i = 0; i < bpc->chip.npwm; i++) { + struct berlin_pwm_channel *channel; + + channel = pwm_get_chip_data(&bpc->chip.pwms[i]); + if (!channel) + continue; + + berlin_pwm_writel(bpc, i, channel->ctrl, BERLIN_PWM_CONTROL); + berlin_pwm_writel(bpc, i, channel->duty, BERLIN_PWM_DUTY); + berlin_pwm_writel(bpc, i, channel->tcnt, BERLIN_PWM_TCNT); + berlin_pwm_writel(bpc, i, channel->enable, BERLIN_PWM_ENABLE); + } + + return 0; +} +#endif + +static SIMPLE_DEV_PM_OPS(berlin_pwm_pm_ops, berlin_pwm_suspend, + berlin_pwm_resume); + +static struct platform_driver berlin_pwm_driver = { + .probe = berlin_pwm_probe, + .remove_new = berlin_pwm_remove, + .driver = { + .name = "berlin-pwm", + .of_match_table = berlin_pwm_match, + .pm = &berlin_pwm_pm_ops, + }, +}; +module_platform_driver(berlin_pwm_driver); + +MODULE_AUTHOR("Antoine Tenart "); +MODULE_DESCRIPTION("Marvell Berlin PWM driver"); +MODULE_LICENSE("GPL v2"); -- cgit v1.2.3