1 // SPDX-License-Identifier: GPL-2.0-or-later
3  * Broadcom BCM7038 PWM driver
19 #include <linux/pwm.h>
41  * Maximum control word value allowed when variable-frequency PWM is used as a
42  * clock for the constant-frequency PMW.
61 				    unsigned int offset)  in brcmstb_pwm_readl()  argument
64 		return __raw_readl(p->base + offset);  in brcmstb_pwm_readl()
66 		return readl_relaxed(p->base + offset);  in brcmstb_pwm_readl()
70 				      unsigned int offset)  in brcmstb_pwm_writel()  argument
73 		__raw_writel(value, p->base + offset);  in brcmstb_pwm_writel()
75 		writel_relaxed(value, p->base + offset);  in brcmstb_pwm_writel()
87  * W = cword, if cword < 2 ^ 15 else 16-bit 2's complement of cword
89  * Fv = W x 2 ^ -16 x 27Mhz (reference clock)
93  * The PWM core framework specifies that the "duty_ns" parameter is in fact the
96 static int brcmstb_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,  in brcmstb_pwm_config()  argument
101 	unsigned int channel = pwm->hwpwm;  in brcmstb_pwm_config()
111 		pc = PWM_ON_PERIOD_MAX - 1;  in brcmstb_pwm_config()
122 		rate = (u64)clk_get_rate(p->clk) * (u64)cword;  in brcmstb_pwm_config()
133 			return -EINVAL;  in brcmstb_pwm_config()
152 			return -EINVAL;  in brcmstb_pwm_config()
195 static int brcmstb_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,  in brcmstb_pwm_apply()  argument
201 	if (state->polarity != PWM_POLARITY_NORMAL)  in brcmstb_pwm_apply()
202 		return -EINVAL;  in brcmstb_pwm_apply()
204 	if (!state->enabled) {  in brcmstb_pwm_apply()
205 		if (pwm->state.enabled)  in brcmstb_pwm_apply()
206 			brcmstb_pwm_enable_set(p, pwm->hwpwm, false);  in brcmstb_pwm_apply()
211 	err = brcmstb_pwm_config(chip, pwm, state->duty_cycle, state->period);  in brcmstb_pwm_apply()
215 	if (!pwm->state.enabled)  in brcmstb_pwm_apply()
216 		brcmstb_pwm_enable_set(p, pwm->hwpwm, true);  in brcmstb_pwm_apply()
226 	{ .compatible = "brcm,bcm7038-pwm", },
236 	p = devm_kzalloc(&pdev->dev, sizeof(*p), GFP_KERNEL);  in brcmstb_pwm_probe()
238 		return -ENOMEM;  in brcmstb_pwm_probe()
240 	p->clk = devm_clk_get_enabled(&pdev->dev, NULL);  in brcmstb_pwm_probe()
241 	if (IS_ERR(p->clk))  in brcmstb_pwm_probe()
242 		return dev_err_probe(&pdev->dev, PTR_ERR(p->clk),  in brcmstb_pwm_probe()
247 	p->chip.dev = &pdev->dev;  in brcmstb_pwm_probe()
248 	p->chip.ops = &brcmstb_pwm_ops;  in brcmstb_pwm_probe()
249 	p->chip.npwm = 2;  in brcmstb_pwm_probe()
251 	p->base = devm_platform_ioremap_resource(pdev, 0);  in brcmstb_pwm_probe()
252 	if (IS_ERR(p->base))  in brcmstb_pwm_probe()
253 		return PTR_ERR(p->base);  in brcmstb_pwm_probe()
255 	ret = devm_pwmchip_add(&pdev->dev, &p->chip);  in brcmstb_pwm_probe()
257 		return dev_err_probe(&pdev->dev, ret, "failed to add PWM chip\n");  in brcmstb_pwm_probe()
266 	clk_disable_unprepare(p->clk);  in brcmstb_pwm_suspend()
275 	return clk_prepare_enable(p->clk);  in brcmstb_pwm_resume()
284 		.name = "pwm-brcmstb",
292 MODULE_DESCRIPTION("Broadcom STB PWM driver");
293 MODULE_ALIAS("platform:pwm-brcmstb");