1 // SPDX-License-Identifier: GPL-2.0-only
5  * PWM (mis)used as clock output
7 #include <linux/clk-provider.h>
12 #include <linux/pwm.h>
16 	struct pwm_device *pwm;  member
29 	return pwm_enable(clk_pwm->pwm);  in clk_pwm_prepare()
36 	pwm_disable(clk_pwm->pwm);  in clk_pwm_unprepare()
44 	return clk_pwm->fixed_rate;  in clk_pwm_recalc_rate()
52 	pwm_get_state(clk_pwm->pwm, &state);  in clk_pwm_get_duty_cycle()
54 	duty->num = state.duty_cycle;  in clk_pwm_get_duty_cycle()
55 	duty->den = state.period;  in clk_pwm_get_duty_cycle()
69 	struct device_node *node = pdev->dev.of_node;  in clk_pwm_probe()
72 	struct pwm_device *pwm;  in clk_pwm_probe()  local
77 	clk_pwm = devm_kzalloc(&pdev->dev, sizeof(*clk_pwm), GFP_KERNEL);  in clk_pwm_probe()
79 		return -ENOMEM;  in clk_pwm_probe()
81 	pwm = devm_pwm_get(&pdev->dev, NULL);  in clk_pwm_probe()
82 	if (IS_ERR(pwm))  in clk_pwm_probe()
83 		return PTR_ERR(pwm);  in clk_pwm_probe()
85 	pwm_get_args(pwm, &pargs);  in clk_pwm_probe()
86 	if (!pargs.period) {  in clk_pwm_probe()
87 		dev_err(&pdev->dev, "invalid PWM period\n");  in clk_pwm_probe()
88 		return -EINVAL;  in clk_pwm_probe()
91 	if (of_property_read_u32(node, "clock-frequency", &clk_pwm->fixed_rate))  in clk_pwm_probe()
92 		clk_pwm->fixed_rate = div64_u64(NSEC_PER_SEC, pargs.period);  in clk_pwm_probe()
94 	if (!clk_pwm->fixed_rate) {  in clk_pwm_probe()
95 		dev_err(&pdev->dev, "fixed_rate cannot be zero\n");  in clk_pwm_probe()
96 		return -EINVAL;  in clk_pwm_probe()
99 	if (pargs.period != NSEC_PER_SEC / clk_pwm->fixed_rate &&  in clk_pwm_probe()
100 	    pargs.period != DIV_ROUND_UP(NSEC_PER_SEC, clk_pwm->fixed_rate)) {  in clk_pwm_probe()
101 		dev_err(&pdev->dev,  in clk_pwm_probe()
102 			"clock-frequency does not match PWM period\n");  in clk_pwm_probe()
103 		return -EINVAL;  in clk_pwm_probe()
108 	 * atomic PWM API.  in clk_pwm_probe()
110 	pwm_apply_args(pwm);  in clk_pwm_probe()
111 	ret = pwm_config(pwm, (pargs.period + 1) >> 1, pargs.period);  in clk_pwm_probe()
115 	clk_name = node->name;  in clk_pwm_probe()
116 	of_property_read_string(node, "clock-output-names", &clk_name);  in clk_pwm_probe()
123 	clk_pwm->pwm = pwm;  in clk_pwm_probe()
124 	clk_pwm->hw.init = &init;  in clk_pwm_probe()
125 	ret = devm_clk_hw_register(&pdev->dev, &clk_pwm->hw);  in clk_pwm_probe()
129 	return of_clk_add_hw_provider(node, of_clk_hw_simple_get, &clk_pwm->hw);  in clk_pwm_probe()
134 	of_clk_del_provider(pdev->dev.of_node);  in clk_pwm_remove()
138 	{ .compatible = "pwm-clock" },
147 		.name = "pwm-clock",
155 MODULE_DESCRIPTION("PWM clock driver");