23 #include <linux/pwm.h>
28  * The Kona PWM has some unusual characteristics.  Here are the main points.
44  * 5) When the external clock that feeds the PWM is disabled, output is pegged
85 	unsigned int value = readl(kp->base + PWM_CONTROL_OFFSET);  in kona_pwmc_prepare_for_settings()
89 	writel(value, kp->base + PWM_CONTROL_OFFSET);  in kona_pwmc_prepare_for_settings()
93 	 * it. Failing to do this may result in no PWM signal.  in kona_pwmc_prepare_for_settings()
100 	unsigned int value = readl(kp->base + PWM_CONTROL_OFFSET);  in kona_pwmc_apply_settings()
105 	writel(value, kp->base + PWM_CONTROL_OFFSET);  in kona_pwmc_apply_settings()
111 static int kona_pwmc_config(struct pwm_chip *chip, struct pwm_device *pwm,  in kona_pwmc_config()  argument
117 	unsigned int value, chan = pwm->hwpwm;  in kona_pwmc_config()
130 	rate = clk_get_rate(kp->clk);  in kona_pwmc_config()
142 			return -EINVAL;  in kona_pwmc_config()
150 			return -EINVAL;  in kona_pwmc_config()
156 	 * validated immediately instead of on enable.  in kona_pwmc_config()
158 	if (pwm_is_enabled(pwm)) {  in kona_pwmc_config()
161 		value = readl(kp->base + PRESCALE_OFFSET);  in kona_pwmc_config()
164 		writel(value, kp->base + PRESCALE_OFFSET);  in kona_pwmc_config()
166 		writel(pc, kp->base + PERIOD_COUNT_OFFSET(chan));  in kona_pwmc_config()
168 		writel(dc, kp->base + DUTY_CYCLE_HIGH_OFFSET(chan));  in kona_pwmc_config()
176 static int kona_pwmc_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm,  in kona_pwmc_set_polarity()  argument
180 	unsigned int chan = pwm->hwpwm;  in kona_pwmc_set_polarity()
184 	ret = clk_prepare_enable(kp->clk);  in kona_pwmc_set_polarity()
186 		dev_err(chip->dev, "failed to enable clock: %d\n", ret);  in kona_pwmc_set_polarity()
192 	value = readl(kp->base + PWM_CONTROL_OFFSET);  in kona_pwmc_set_polarity()
199 	writel(value, kp->base + PWM_CONTROL_OFFSET);  in kona_pwmc_set_polarity()
203 	clk_disable_unprepare(kp->clk);  in kona_pwmc_set_polarity()
208 static int kona_pwmc_enable(struct pwm_chip *chip, struct pwm_device *pwm)  in kona_pwmc_enable()  argument
213 	ret = clk_prepare_enable(kp->clk);  in kona_pwmc_enable()
215 		dev_err(chip->dev, "failed to enable clock: %d\n", ret);  in kona_pwmc_enable()
219 	ret = kona_pwmc_config(chip, pwm, pwm_get_duty_cycle(pwm),  in kona_pwmc_enable()
220 			       pwm_get_period(pwm));  in kona_pwmc_enable()
222 		clk_disable_unprepare(kp->clk);  in kona_pwmc_enable()
229 static void kona_pwmc_disable(struct pwm_chip *chip, struct pwm_device *pwm)  in kona_pwmc_disable()  argument
232 	unsigned int chan = pwm->hwpwm;  in kona_pwmc_disable()
238 	writel(0, kp->base + DUTY_CYCLE_HIGH_OFFSET(chan));  in kona_pwmc_disable()
239 	writel(0, kp->base + PERIOD_COUNT_OFFSET(chan));  in kona_pwmc_disable()
242 	value = readl(kp->base + PRESCALE_OFFSET);  in kona_pwmc_disable()
244 	writel(value, kp->base + PRESCALE_OFFSET);  in kona_pwmc_disable()
248 	clk_disable_unprepare(kp->clk);  in kona_pwmc_disable()
254 	.enable = kona_pwmc_enable,
266 	kp = devm_kzalloc(&pdev->dev, sizeof(*kp), GFP_KERNEL);  in kona_pwmc_probe()
268 		return -ENOMEM;  in kona_pwmc_probe()
270 	kp->chip.dev = &pdev->dev;  in kona_pwmc_probe()
271 	kp->chip.ops = &kona_pwm_ops;  in kona_pwmc_probe()
272 	kp->chip.npwm = 6;  in kona_pwmc_probe()
274 	kp->base = devm_platform_ioremap_resource(pdev, 0);  in kona_pwmc_probe()
275 	if (IS_ERR(kp->base))  in kona_pwmc_probe()
276 		return PTR_ERR(kp->base);  in kona_pwmc_probe()
278 	kp->clk = devm_clk_get(&pdev->dev, NULL);  in kona_pwmc_probe()
279 	if (IS_ERR(kp->clk)) {  in kona_pwmc_probe()
280 		dev_err(&pdev->dev, "failed to get clock: %ld\n",  in kona_pwmc_probe()
281 			PTR_ERR(kp->clk));  in kona_pwmc_probe()
282 		return PTR_ERR(kp->clk);  in kona_pwmc_probe()
285 	ret = clk_prepare_enable(kp->clk);  in kona_pwmc_probe()
287 		dev_err(&pdev->dev, "failed to enable clock: %d\n", ret);  in kona_pwmc_probe()
292 	for (chan = 0; chan < kp->chip.npwm; chan++)  in kona_pwmc_probe()
295 	writel(value, kp->base + PWM_CONTROL_OFFSET);  in kona_pwmc_probe()
297 	clk_disable_unprepare(kp->clk);  in kona_pwmc_probe()
299 	ret = devm_pwmchip_add(&pdev->dev, &kp->chip);  in kona_pwmc_probe()
301 		dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret);  in kona_pwmc_probe()
307 	{ .compatible = "brcm,kona-pwm" },
314 		.name = "bcm-kona-pwm",
321 MODULE_AUTHOR("Broadcom Corporation <bcm-kernel-feedback-list@broadcom.com>");
323 MODULE_DESCRIPTION("Broadcom Kona PWM driver");