1 // SPDX-License-Identifier: GPL-2.0
6 #include <linux/clk.h>
12 #include <linux/pwm.h>
17 #define PWM_MODE		0x80		/* set timer in PWM mode */
30 	struct clk *clk;  member
38 static int bcm2835_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)  in bcm2835_pwm_request()  argument
43 	value = readl(pc->base + PWM_CONTROL);  in bcm2835_pwm_request()
44 	value &= ~(PWM_CONTROL_MASK << PWM_CONTROL_SHIFT(pwm->hwpwm));  in bcm2835_pwm_request()
45 	value |= (PWM_MODE << PWM_CONTROL_SHIFT(pwm->hwpwm));  in bcm2835_pwm_request()
46 	writel(value, pc->base + PWM_CONTROL);  in bcm2835_pwm_request()
51 static void bcm2835_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)  in bcm2835_pwm_free()  argument
56 	value = readl(pc->base + PWM_CONTROL);  in bcm2835_pwm_free()
57 	value &= ~(PWM_CONTROL_MASK << PWM_CONTROL_SHIFT(pwm->hwpwm));  in bcm2835_pwm_free()
58 	writel(value, pc->base + PWM_CONTROL);  in bcm2835_pwm_free()
61 static int bcm2835_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,  in bcm2835_pwm_config()  argument
65 	unsigned long rate = clk_get_rate(pc->clk);  in bcm2835_pwm_config()
70 		dev_err(pc->dev, "failed to get clock rate\n");  in bcm2835_pwm_config()
71 		return -EINVAL;  in bcm2835_pwm_config()
78 		return -EINVAL;  in bcm2835_pwm_config()
81 	       pc->base + DUTY(pwm->hwpwm));  in bcm2835_pwm_config()
82 	writel(period, pc->base + PERIOD(pwm->hwpwm));  in bcm2835_pwm_config()
87 static int bcm2835_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)  in bcm2835_pwm_enable()  argument
92 	value = readl(pc->base + PWM_CONTROL);  in bcm2835_pwm_enable()
93 	value |= PWM_ENABLE << PWM_CONTROL_SHIFT(pwm->hwpwm);  in bcm2835_pwm_enable()
94 	writel(value, pc->base + PWM_CONTROL);  in bcm2835_pwm_enable()
99 static void bcm2835_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)  in bcm2835_pwm_disable()  argument
104 	value = readl(pc->base + PWM_CONTROL);  in bcm2835_pwm_disable()
105 	value &= ~(PWM_ENABLE << PWM_CONTROL_SHIFT(pwm->hwpwm));  in bcm2835_pwm_disable()
106 	writel(value, pc->base + PWM_CONTROL);  in bcm2835_pwm_disable()
109 static int bcm2835_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm,  in bcm2835_set_polarity()  argument
115 	value = readl(pc->base + PWM_CONTROL);  in bcm2835_set_polarity()
118 		value &= ~(PWM_POLARITY << PWM_CONTROL_SHIFT(pwm->hwpwm));  in bcm2835_set_polarity()
120 		value |= PWM_POLARITY << PWM_CONTROL_SHIFT(pwm->hwpwm);  in bcm2835_set_polarity()
122 	writel(value, pc->base + PWM_CONTROL);  in bcm2835_set_polarity()
143 	pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);  in bcm2835_pwm_probe()
145 		return -ENOMEM;  in bcm2835_pwm_probe()
147 	pc->dev = &pdev->dev;  in bcm2835_pwm_probe()
150 	pc->base = devm_ioremap_resource(&pdev->dev, res);  in bcm2835_pwm_probe()
151 	if (IS_ERR(pc->base))  in bcm2835_pwm_probe()
152 		return PTR_ERR(pc->base);  in bcm2835_pwm_probe()
154 	pc->clk = devm_clk_get(&pdev->dev, NULL);  in bcm2835_pwm_probe()
155 	if (IS_ERR(pc->clk))  in bcm2835_pwm_probe()
156 		return dev_err_probe(&pdev->dev, PTR_ERR(pc->clk),  in bcm2835_pwm_probe()
159 	ret = clk_prepare_enable(pc->clk);  in bcm2835_pwm_probe()
163 	pc->chip.dev = &pdev->dev;  in bcm2835_pwm_probe()
164 	pc->chip.ops = &bcm2835_pwm_ops;  in bcm2835_pwm_probe()
165 	pc->chip.base = -1;  in bcm2835_pwm_probe()
166 	pc->chip.npwm = 2;  in bcm2835_pwm_probe()
167 	pc->chip.of_xlate = of_pwm_xlate_with_flags;  in bcm2835_pwm_probe()
168 	pc->chip.of_pwm_n_cells = 3;  in bcm2835_pwm_probe()
172 	ret = pwmchip_add(&pc->chip);  in bcm2835_pwm_probe()
179 	clk_disable_unprepare(pc->clk);  in bcm2835_pwm_probe()
187 	clk_disable_unprepare(pc->clk);  in bcm2835_pwm_remove()
189 	return pwmchip_remove(&pc->chip);  in bcm2835_pwm_remove()
193 	{ .compatible = "brcm,bcm2835-pwm", },
200 		.name = "bcm2835-pwm",
209 MODULE_DESCRIPTION("Broadcom BCM2835 PWM driver");