1 // SPDX-License-Identifier: GPL-2.0-or-later
11 #include <linux/clk.h>
41  * Maximum control word value allowed when variable-frequency PWM is used as a
42  * clock for the constant-frequency PMW.
56 	struct clk *clk;  member
63 		return __raw_readl(p->base + offset);  in brcmstb_pwm_readl()
65 		return readl_relaxed(p->base + offset);  in brcmstb_pwm_readl()
72 		__raw_writel(value, p->base + offset);  in brcmstb_pwm_writel()
74 		writel_relaxed(value, p->base + offset);  in brcmstb_pwm_writel()
83  * Fv is derived from the variable frequency output. The variable frequency
86  * W = cword, if cword < 2 ^ 15 else 16-bit 2's complement of cword
88  * Fv = W x 2 ^ -16 x 27Mhz (reference clock)
100 	unsigned int channel = pwm->hwpwm;  in brcmstb_pwm_config()
106 	 * produce a flat 100% duty cycle signal, and max out the "on" time  in brcmstb_pwm_config()
110 		pc = PWM_ON_PERIOD_MAX - 1;  in brcmstb_pwm_config()
118 		 * Calculate the base rate from base frequency and current  in brcmstb_pwm_config()
121 		rate = (u64)clk_get_rate(p->clk) * (u64)cword;  in brcmstb_pwm_config()
132 			return -EINVAL;  in brcmstb_pwm_config()
140 		 * frequency generator to output a 50% duty cycle variable  in brcmstb_pwm_config()
141 		 * frequency which is used as input clock to the fixed  in brcmstb_pwm_config()
142 		 * frequency generator.  in brcmstb_pwm_config()
151 			return -EINVAL;  in brcmstb_pwm_config()
156 	 * Configure the defined "cword" value to have the variable frequency  in brcmstb_pwm_config()
157 	 * generator output a base frequency for the constant frequency  in brcmstb_pwm_config()
163 	/* Select constant frequency signal output */  in brcmstb_pwm_config()
200 	if (state->polarity != PWM_POLARITY_NORMAL)  in brcmstb_pwm_apply()
201 		return -EINVAL;  in brcmstb_pwm_apply()
203 	if (!state->enabled) {  in brcmstb_pwm_apply()
204 		if (pwm->state.enabled)  in brcmstb_pwm_apply()
205 			brcmstb_pwm_enable_set(p, pwm->hwpwm, false);  in brcmstb_pwm_apply()
210 	err = brcmstb_pwm_config(chip, pwm, state->duty_cycle, state->period);  in brcmstb_pwm_apply()
214 	if (!pwm->state.enabled)  in brcmstb_pwm_apply()
215 		brcmstb_pwm_enable_set(p, pwm->hwpwm, true);  in brcmstb_pwm_apply()
225 	{ .compatible = "brcm,bcm7038-pwm", },
236 	chip = devm_pwmchip_alloc(&pdev->dev, 2, sizeof(*p));  in brcmstb_pwm_probe()
241 	p->clk = devm_clk_get_enabled(&pdev->dev, NULL);  in brcmstb_pwm_probe()
242 	if (IS_ERR(p->clk))  in brcmstb_pwm_probe()
243 		return dev_err_probe(&pdev->dev, PTR_ERR(p->clk),  in brcmstb_pwm_probe()
248 	chip->ops = &brcmstb_pwm_ops;  in brcmstb_pwm_probe()
250 	p->base = devm_platform_ioremap_resource(pdev, 0);  in brcmstb_pwm_probe()
251 	if (IS_ERR(p->base))  in brcmstb_pwm_probe()
252 		return PTR_ERR(p->base);  in brcmstb_pwm_probe()
254 	ret = devm_pwmchip_add(&pdev->dev, chip);  in brcmstb_pwm_probe()
256 		return dev_err_probe(&pdev->dev, ret, "failed to add PWM chip\n");  in brcmstb_pwm_probe()
265 	clk_disable_unprepare(p->clk);  in brcmstb_pwm_suspend()
274 	return clk_prepare_enable(p->clk);  in brcmstb_pwm_resume()
283 		.name = "pwm-brcmstb",
292 MODULE_ALIAS("platform:pwm-brcmstb");