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Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 675 mass ave cambridge ma 02139 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 35 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Armijn Hemel <armijn@tjaldur.nl> Reviewed-by: Richard Fontana <rfontana@redhat.com> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.655028468@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
208 lines
4.8 KiB
C
208 lines
4.8 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
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* JZ4740 platform PWM support
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*/
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#include <linux/clk.h>
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#include <linux/err.h>
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#include <linux/gpio.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/of_device.h>
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#include <linux/platform_device.h>
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#include <linux/pwm.h>
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#include <asm/mach-jz4740/timer.h>
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#define NUM_PWM 8
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struct jz4740_pwm_chip {
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struct pwm_chip chip;
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struct clk *clk;
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};
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static inline struct jz4740_pwm_chip *to_jz4740(struct pwm_chip *chip)
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{
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return container_of(chip, struct jz4740_pwm_chip, chip);
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}
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static int jz4740_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
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{
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/*
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* Timers 0 and 1 are used for system tasks, so they are unavailable
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* for use as PWMs.
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*/
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if (pwm->hwpwm < 2)
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return -EBUSY;
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jz4740_timer_start(pwm->hwpwm);
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return 0;
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}
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static void jz4740_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
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{
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jz4740_timer_set_ctrl(pwm->hwpwm, 0);
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jz4740_timer_stop(pwm->hwpwm);
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}
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static int jz4740_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
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{
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uint32_t ctrl = jz4740_timer_get_ctrl(pwm->pwm);
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ctrl |= JZ_TIMER_CTRL_PWM_ENABLE;
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jz4740_timer_set_ctrl(pwm->hwpwm, ctrl);
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jz4740_timer_enable(pwm->hwpwm);
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return 0;
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}
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static void jz4740_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
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{
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uint32_t ctrl = jz4740_timer_get_ctrl(pwm->hwpwm);
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/* Disable PWM output.
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* In TCU2 mode (channel 1/2 on JZ4750+), this must be done before the
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* counter is stopped, while in TCU1 mode the order does not matter.
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*/
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ctrl &= ~JZ_TIMER_CTRL_PWM_ENABLE;
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jz4740_timer_set_ctrl(pwm->hwpwm, ctrl);
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/* Stop counter */
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jz4740_timer_disable(pwm->hwpwm);
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}
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static int jz4740_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
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int duty_ns, int period_ns)
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{
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struct jz4740_pwm_chip *jz4740 = to_jz4740(pwm->chip);
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unsigned long long tmp;
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unsigned long period, duty;
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unsigned int prescaler = 0;
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uint16_t ctrl;
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bool is_enabled;
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tmp = (unsigned long long)clk_get_rate(jz4740->clk) * period_ns;
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do_div(tmp, 1000000000);
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period = tmp;
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while (period > 0xffff && prescaler < 6) {
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period >>= 2;
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++prescaler;
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}
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if (prescaler == 6)
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return -EINVAL;
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tmp = (unsigned long long)period * duty_ns;
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do_div(tmp, period_ns);
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duty = period - tmp;
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if (duty >= period)
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duty = period - 1;
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is_enabled = jz4740_timer_is_enabled(pwm->hwpwm);
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if (is_enabled)
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jz4740_pwm_disable(chip, pwm);
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jz4740_timer_set_count(pwm->hwpwm, 0);
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jz4740_timer_set_duty(pwm->hwpwm, duty);
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jz4740_timer_set_period(pwm->hwpwm, period);
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ctrl = JZ_TIMER_CTRL_PRESCALER(prescaler) | JZ_TIMER_CTRL_SRC_EXT |
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JZ_TIMER_CTRL_PWM_ABBRUPT_SHUTDOWN;
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jz4740_timer_set_ctrl(pwm->hwpwm, ctrl);
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if (is_enabled)
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jz4740_pwm_enable(chip, pwm);
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return 0;
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}
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static int jz4740_pwm_set_polarity(struct pwm_chip *chip,
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struct pwm_device *pwm, enum pwm_polarity polarity)
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{
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uint32_t ctrl = jz4740_timer_get_ctrl(pwm->pwm);
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switch (polarity) {
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case PWM_POLARITY_NORMAL:
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ctrl &= ~JZ_TIMER_CTRL_PWM_ACTIVE_LOW;
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break;
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case PWM_POLARITY_INVERSED:
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ctrl |= JZ_TIMER_CTRL_PWM_ACTIVE_LOW;
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break;
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}
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jz4740_timer_set_ctrl(pwm->hwpwm, ctrl);
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return 0;
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}
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static const struct pwm_ops jz4740_pwm_ops = {
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.request = jz4740_pwm_request,
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.free = jz4740_pwm_free,
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.config = jz4740_pwm_config,
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.set_polarity = jz4740_pwm_set_polarity,
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.enable = jz4740_pwm_enable,
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.disable = jz4740_pwm_disable,
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.owner = THIS_MODULE,
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};
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static int jz4740_pwm_probe(struct platform_device *pdev)
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{
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struct jz4740_pwm_chip *jz4740;
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jz4740 = devm_kzalloc(&pdev->dev, sizeof(*jz4740), GFP_KERNEL);
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if (!jz4740)
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return -ENOMEM;
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jz4740->clk = devm_clk_get(&pdev->dev, "ext");
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if (IS_ERR(jz4740->clk))
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return PTR_ERR(jz4740->clk);
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jz4740->chip.dev = &pdev->dev;
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jz4740->chip.ops = &jz4740_pwm_ops;
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jz4740->chip.npwm = NUM_PWM;
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jz4740->chip.base = -1;
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jz4740->chip.of_xlate = of_pwm_xlate_with_flags;
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jz4740->chip.of_pwm_n_cells = 3;
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platform_set_drvdata(pdev, jz4740);
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return pwmchip_add(&jz4740->chip);
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}
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static int jz4740_pwm_remove(struct platform_device *pdev)
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{
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struct jz4740_pwm_chip *jz4740 = platform_get_drvdata(pdev);
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return pwmchip_remove(&jz4740->chip);
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}
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#ifdef CONFIG_OF
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static const struct of_device_id jz4740_pwm_dt_ids[] = {
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{ .compatible = "ingenic,jz4740-pwm", },
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{ .compatible = "ingenic,jz4770-pwm", },
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{ .compatible = "ingenic,jz4780-pwm", },
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{},
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};
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MODULE_DEVICE_TABLE(of, jz4740_pwm_dt_ids);
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#endif
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static struct platform_driver jz4740_pwm_driver = {
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.driver = {
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.name = "jz4740-pwm",
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.of_match_table = of_match_ptr(jz4740_pwm_dt_ids),
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},
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.probe = jz4740_pwm_probe,
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.remove = jz4740_pwm_remove,
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};
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module_platform_driver(jz4740_pwm_driver);
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MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
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MODULE_DESCRIPTION("Ingenic JZ4740 PWM driver");
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MODULE_ALIAS("platform:jz4740-pwm");
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MODULE_LICENSE("GPL");
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