1 // SPDX-License-Identifier: GPL-2.0-or-later
3  * PWM framework driver for Cirrus Logic EP93xx
9  *   platform device ep93xx-pwm.1 - PWMOUT1 (EGPIO14)
12  *   platform device ep93xx-pwm.0 - PWMOUT
15  *   platform device ep93xx-pwm.0 - PWMOUT
16  *   platform device ep93xx-pwm.1 - PWMOUT1 (EGPIO14)
22 #include <linux/clk.h>
25 #include <linux/pwm.h>
38 	struct clk *clk;  member
47 static int ep93xx_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)  in ep93xx_pwm_request()  argument
49 	struct platform_device *pdev = to_platform_device(chip->dev);  in ep93xx_pwm_request()
54 static void ep93xx_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)  in ep93xx_pwm_free()  argument
56 	struct platform_device *pdev = to_platform_device(chip->dev);  in ep93xx_pwm_free()
61 static int ep93xx_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,  in ep93xx_pwm_config()  argument
65 	void __iomem *base = ep93xx_pwm->base;  in ep93xx_pwm_config()
73 	 * The clock needs to be enabled to access the PWM registers.  in ep93xx_pwm_config()
76 	if (!pwm_is_enabled(pwm)) {  in ep93xx_pwm_config()
77 		ret = clk_enable(ep93xx_pwm->clk);  in ep93xx_pwm_config()
82 	c = clk_get_rate(ep93xx_pwm->clk);  in ep93xx_pwm_config()
95 		/* Order is important if PWM is running */  in ep93xx_pwm_config()
104 		ret = -EINVAL;  in ep93xx_pwm_config()
107 	if (!pwm_is_enabled(pwm))  in ep93xx_pwm_config()
108 		clk_disable(ep93xx_pwm->clk);  in ep93xx_pwm_config()
113 static int ep93xx_pwm_polarity(struct pwm_chip *chip, struct pwm_device *pwm,  in ep93xx_pwm_polarity()  argument
120 	 * The clock needs to be enabled to access the PWM registers.  in ep93xx_pwm_polarity()
121 	 * Polarity can only be changed when the PWM is disabled.  in ep93xx_pwm_polarity()
123 	ret = clk_enable(ep93xx_pwm->clk);  in ep93xx_pwm_polarity()
128 		writew(0x1, ep93xx_pwm->base + EP93XX_PWMx_INVERT);  in ep93xx_pwm_polarity()
130 		writew(0x0, ep93xx_pwm->base + EP93XX_PWMx_INVERT);  in ep93xx_pwm_polarity()
132 	clk_disable(ep93xx_pwm->clk);  in ep93xx_pwm_polarity()
137 static int ep93xx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)  in ep93xx_pwm_enable()  argument
142 	ret = clk_enable(ep93xx_pwm->clk);  in ep93xx_pwm_enable()
146 	writew(0x1, ep93xx_pwm->base + EP93XX_PWMx_ENABLE);  in ep93xx_pwm_enable()
151 static void ep93xx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)  in ep93xx_pwm_disable()  argument
155 	writew(0x0, ep93xx_pwm->base + EP93XX_PWMx_ENABLE);  in ep93xx_pwm_disable()
156 	clk_disable(ep93xx_pwm->clk);  in ep93xx_pwm_disable()
175 	ep93xx_pwm = devm_kzalloc(&pdev->dev, sizeof(*ep93xx_pwm), GFP_KERNEL);  in ep93xx_pwm_probe()
177 		return -ENOMEM;  in ep93xx_pwm_probe()
180 	ep93xx_pwm->base = devm_ioremap_resource(&pdev->dev, res);  in ep93xx_pwm_probe()
181 	if (IS_ERR(ep93xx_pwm->base))  in ep93xx_pwm_probe()
182 		return PTR_ERR(ep93xx_pwm->base);  in ep93xx_pwm_probe()
184 	ep93xx_pwm->clk = devm_clk_get(&pdev->dev, "pwm_clk");  in ep93xx_pwm_probe()
185 	if (IS_ERR(ep93xx_pwm->clk))  in ep93xx_pwm_probe()
186 		return PTR_ERR(ep93xx_pwm->clk);  in ep93xx_pwm_probe()
188 	ep93xx_pwm->chip.dev = &pdev->dev;  in ep93xx_pwm_probe()
189 	ep93xx_pwm->chip.ops = &ep93xx_pwm_ops;  in ep93xx_pwm_probe()
190 	ep93xx_pwm->chip.base = -1;  in ep93xx_pwm_probe()
191 	ep93xx_pwm->chip.npwm = 1;  in ep93xx_pwm_probe()
193 	ret = pwmchip_add(&ep93xx_pwm->chip);  in ep93xx_pwm_probe()
205 	return pwmchip_remove(&ep93xx_pwm->chip);  in ep93xx_pwm_remove()
210 		.name = "ep93xx-pwm",
217 MODULE_DESCRIPTION("Cirrus Logic EP93xx PWM driver");
220 MODULE_ALIAS("platform:ep93xx-pwm");