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.
57 	struct clk *clk;  member
65 		return __raw_readl(p->base + offset);  in brcmstb_pwm_readl()
67 		return readl_relaxed(p->base + offset);  in brcmstb_pwm_readl()
74 		__raw_writel(value, p->base + offset);  in brcmstb_pwm_writel()
76 		writel_relaxed(value, p->base + offset);  in brcmstb_pwm_writel()
85  * Fv is derived from the variable frequency output. The variable frequency
88  * W = cword, if cword < 2 ^ 15 else 16-bit 2's complement of cword
90  * Fv = W x 2 ^ -16 x 27Mhz (reference clock)
102 	unsigned int channel = pwm->hwpwm;  in brcmstb_pwm_config()
108 	 * produce a flat 100% duty cycle signal, and max out the "on" time  in brcmstb_pwm_config()
112 		pc = PWM_ON_PERIOD_MAX - 1;  in brcmstb_pwm_config()
120 		 * Calculate the base rate from base frequency and current  in brcmstb_pwm_config()
123 		rate = (u64)clk_get_rate(p->clk) * (u64)cword;  in brcmstb_pwm_config()
139 			return -EINVAL;  in brcmstb_pwm_config()
147 		 * frequency generator to output a 50% duty cycle variable  in brcmstb_pwm_config()
148 		 * frequency which is used as input clock to the fixed  in brcmstb_pwm_config()
149 		 * frequency generator.  in brcmstb_pwm_config()
158 			return -EINVAL;  in brcmstb_pwm_config()
163 	 * Configure the defined "cword" value to have the variable frequency  in brcmstb_pwm_config()
164 	 * generator output a base frequency for the constant frequency  in brcmstb_pwm_config()
167 	spin_lock(&p->lock);  in brcmstb_pwm_config()
171 	/* Select constant frequency signal output */  in brcmstb_pwm_config()
179 	spin_unlock(&p->lock);  in brcmstb_pwm_config()
190 	spin_lock(&p->lock);  in brcmstb_pwm_enable_set()
202 	spin_unlock(&p->lock);  in brcmstb_pwm_enable_set()
209 	brcmstb_pwm_enable_set(p, pwm->hwpwm, true);  in brcmstb_pwm_enable()
218 	brcmstb_pwm_enable_set(p, pwm->hwpwm, false);  in brcmstb_pwm_disable()
229 	{ .compatible = "brcm,bcm7038-pwm", },
240 	p = devm_kzalloc(&pdev->dev, sizeof(*p), GFP_KERNEL);  in brcmstb_pwm_probe()
242 		return -ENOMEM;  in brcmstb_pwm_probe()
244 	spin_lock_init(&p->lock);  in brcmstb_pwm_probe()
246 	p->clk = devm_clk_get(&pdev->dev, NULL);  in brcmstb_pwm_probe()
247 	if (IS_ERR(p->clk)) {  in brcmstb_pwm_probe()
248 		dev_err(&pdev->dev, "failed to obtain clock\n");  in brcmstb_pwm_probe()
249 		return PTR_ERR(p->clk);  in brcmstb_pwm_probe()
252 	ret = clk_prepare_enable(p->clk);  in brcmstb_pwm_probe()
254 		dev_err(&pdev->dev, "failed to enable clock: %d\n", ret);  in brcmstb_pwm_probe()
260 	p->chip.dev = &pdev->dev;  in brcmstb_pwm_probe()
261 	p->chip.ops = &brcmstb_pwm_ops;  in brcmstb_pwm_probe()
262 	p->chip.base = -1;  in brcmstb_pwm_probe()
263 	p->chip.npwm = 2;  in brcmstb_pwm_probe()
266 	p->base = devm_ioremap_resource(&pdev->dev, res);  in brcmstb_pwm_probe()
267 	if (IS_ERR(p->base)) {  in brcmstb_pwm_probe()
268 		ret = PTR_ERR(p->base);  in brcmstb_pwm_probe()
272 	ret = pwmchip_add(&p->chip);  in brcmstb_pwm_probe()
274 		dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret);  in brcmstb_pwm_probe()
281 	clk_disable_unprepare(p->clk);  in brcmstb_pwm_probe()
290 	ret = pwmchip_remove(&p->chip);  in brcmstb_pwm_remove()
291 	clk_disable_unprepare(p->clk);  in brcmstb_pwm_remove()
301 	clk_disable(p->clk);  in brcmstb_pwm_suspend()
310 	clk_enable(p->clk);  in brcmstb_pwm_resume()
323 		.name = "pwm-brcmstb",
332 MODULE_ALIAS("platform:pwm-brcmstb");