From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- drivers/clk/clk-pwm.c | 158 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 158 insertions(+) create mode 100644 drivers/clk/clk-pwm.c (limited to 'drivers/clk/clk-pwm.c') diff --git a/drivers/clk/clk-pwm.c b/drivers/clk/clk-pwm.c new file mode 100644 index 000000000..da2c8eddf --- /dev/null +++ b/drivers/clk/clk-pwm.c @@ -0,0 +1,158 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2014 Philipp Zabel, Pengutronix + * + * PWM (mis)used as clock output + */ +#include +#include +#include +#include +#include +#include + +struct clk_pwm { + struct clk_hw hw; + struct pwm_device *pwm; + u32 fixed_rate; +}; + +static inline struct clk_pwm *to_clk_pwm(struct clk_hw *hw) +{ + return container_of(hw, struct clk_pwm, hw); +} + +static int clk_pwm_prepare(struct clk_hw *hw) +{ + struct clk_pwm *clk_pwm = to_clk_pwm(hw); + + return pwm_enable(clk_pwm->pwm); +} + +static void clk_pwm_unprepare(struct clk_hw *hw) +{ + struct clk_pwm *clk_pwm = to_clk_pwm(hw); + + pwm_disable(clk_pwm->pwm); +} + +static unsigned long clk_pwm_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct clk_pwm *clk_pwm = to_clk_pwm(hw); + + return clk_pwm->fixed_rate; +} + +static int clk_pwm_get_duty_cycle(struct clk_hw *hw, struct clk_duty *duty) +{ + struct clk_pwm *clk_pwm = to_clk_pwm(hw); + struct pwm_state state; + + pwm_get_state(clk_pwm->pwm, &state); + + duty->num = state.duty_cycle; + duty->den = state.period; + + return 0; +} + +static const struct clk_ops clk_pwm_ops = { + .prepare = clk_pwm_prepare, + .unprepare = clk_pwm_unprepare, + .recalc_rate = clk_pwm_recalc_rate, + .get_duty_cycle = clk_pwm_get_duty_cycle, +}; + +static int clk_pwm_probe(struct platform_device *pdev) +{ + struct device_node *node = pdev->dev.of_node; + struct clk_init_data init; + struct clk_pwm *clk_pwm; + struct pwm_device *pwm; + struct pwm_args pargs; + const char *clk_name; + int ret; + + clk_pwm = devm_kzalloc(&pdev->dev, sizeof(*clk_pwm), GFP_KERNEL); + if (!clk_pwm) + return -ENOMEM; + + pwm = devm_pwm_get(&pdev->dev, NULL); + if (IS_ERR(pwm)) + return PTR_ERR(pwm); + + pwm_get_args(pwm, &pargs); + if (!pargs.period) { + dev_err(&pdev->dev, "invalid PWM period\n"); + return -EINVAL; + } + + if (of_property_read_u32(node, "clock-frequency", &clk_pwm->fixed_rate)) + clk_pwm->fixed_rate = div64_u64(NSEC_PER_SEC, pargs.period); + + if (!clk_pwm->fixed_rate) { + dev_err(&pdev->dev, "fixed_rate cannot be zero\n"); + return -EINVAL; + } + + if (pargs.period != NSEC_PER_SEC / clk_pwm->fixed_rate && + pargs.period != DIV_ROUND_UP(NSEC_PER_SEC, clk_pwm->fixed_rate)) { + dev_err(&pdev->dev, + "clock-frequency does not match PWM period\n"); + return -EINVAL; + } + + /* + * FIXME: pwm_apply_args() should be removed when switching to the + * atomic PWM API. + */ + pwm_apply_args(pwm); + ret = pwm_config(pwm, (pargs.period + 1) >> 1, pargs.period); + if (ret < 0) + return ret; + + clk_name = node->name; + of_property_read_string(node, "clock-output-names", &clk_name); + + init.name = clk_name; + init.ops = &clk_pwm_ops; + init.flags = 0; + init.num_parents = 0; + + clk_pwm->pwm = pwm; + clk_pwm->hw.init = &init; + ret = devm_clk_hw_register(&pdev->dev, &clk_pwm->hw); + if (ret) + return ret; + + return of_clk_add_hw_provider(node, of_clk_hw_simple_get, &clk_pwm->hw); +} + +static int clk_pwm_remove(struct platform_device *pdev) +{ + of_clk_del_provider(pdev->dev.of_node); + + return 0; +} + +static const struct of_device_id clk_pwm_dt_ids[] = { + { .compatible = "pwm-clock" }, + { } +}; +MODULE_DEVICE_TABLE(of, clk_pwm_dt_ids); + +static struct platform_driver clk_pwm_driver = { + .probe = clk_pwm_probe, + .remove = clk_pwm_remove, + .driver = { + .name = "pwm-clock", + .of_match_table = clk_pwm_dt_ids, + }, +}; + +module_platform_driver(clk_pwm_driver); + +MODULE_AUTHOR("Philipp Zabel "); +MODULE_DESCRIPTION("PWM clock driver"); +MODULE_LICENSE("GPL"); -- cgit v1.2.3