1 // SPDX-License-Identifier: GPL-2.0-or-later
3  * ECAP PWM driver
5  * Copyright (C) 2012 Texas Instruments, Inc. - https://www.ti.com/
14 #include <linux/pwm.h>
49 static int ecap_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,  in ecap_pwm_config()  argument
57 	c = pc->clk_rate;  in ecap_pwm_config()
66 		c = pc->clk_rate;  in ecap_pwm_config()
74 	value = readw(pc->mmio_base + ECCTL2);  in ecap_pwm_config()
79 	writew(value, pc->mmio_base + ECCTL2);  in ecap_pwm_config()
82 		/* Update active registers if not running */  in ecap_pwm_config()
83 		writel(duty_cycles, pc->mmio_base + CAP2);  in ecap_pwm_config()
84 		writel(period_cycles, pc->mmio_base + CAP1);  in ecap_pwm_config()
88 		 * compare values. This helps current PWM period to  in ecap_pwm_config()
91 		writel(duty_cycles, pc->mmio_base + CAP4);  in ecap_pwm_config()
92 		writel(period_cycles, pc->mmio_base + CAP3);  in ecap_pwm_config()
96 		value = readw(pc->mmio_base + ECCTL2);  in ecap_pwm_config()
99 		writew(value, pc->mmio_base + ECCTL2);  in ecap_pwm_config()
107 static int ecap_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm,  in ecap_pwm_set_polarity()  argument
115 	value = readw(pc->mmio_base + ECCTL2);  in ecap_pwm_set_polarity()
118 		/* Duty cycle defines LOW period of PWM */  in ecap_pwm_set_polarity()
121 		/* Duty cycle defines HIGH period of PWM */  in ecap_pwm_set_polarity()
124 	writew(value, pc->mmio_base + ECCTL2);  in ecap_pwm_set_polarity()
131 static int ecap_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)  in ecap_pwm_enable()  argument
136 	/* Leave clock enabled on enabling PWM */  in ecap_pwm_enable()
143 	value = readw(pc->mmio_base + ECCTL2);  in ecap_pwm_enable()
145 	writew(value, pc->mmio_base + ECCTL2);  in ecap_pwm_enable()
150 static void ecap_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)  in ecap_pwm_disable()  argument
159 	value = readw(pc->mmio_base + ECCTL2);  in ecap_pwm_disable()
161 	writew(value, pc->mmio_base + ECCTL2);  in ecap_pwm_disable()
163 	/* Disable clock on PWM disable */  in ecap_pwm_disable()
167 static int ecap_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,  in ecap_pwm_apply()  argument
168 			  const struct pwm_state *state)  in ecap_pwm_apply()  argument
171 	int enabled = pwm->state.enabled;  in ecap_pwm_apply()
173 	if (state->polarity != pwm->state.polarity) {  in ecap_pwm_apply()
176 			ecap_pwm_disable(chip, pwm);  in ecap_pwm_apply()
180 		err = ecap_pwm_set_polarity(chip, pwm, state->polarity);  in ecap_pwm_apply()
185 	if (!state->enabled) {  in ecap_pwm_apply()
187 			ecap_pwm_disable(chip, pwm);  in ecap_pwm_apply()
191 	if (state->period > NSEC_PER_SEC)  in ecap_pwm_apply()
192 		return -ERANGE;  in ecap_pwm_apply()
194 	err = ecap_pwm_config(chip, pwm, state->duty_cycle,  in ecap_pwm_apply()
195 			      state->period, enabled);  in ecap_pwm_apply()
200 		return ecap_pwm_enable(chip, pwm);  in ecap_pwm_apply()
210 	{ .compatible	= "ti,am3352-ecap" },
211 	{ .compatible	= "ti,am33xx-ecap" },
218 	struct device_node *np = pdev->dev.of_node;  in ecap_pwm_probe()
224 	chip = devm_pwmchip_alloc(&pdev->dev, 1, sizeof(*pc));  in ecap_pwm_probe()
229 	clk = devm_clk_get(&pdev->dev, "fck");  in ecap_pwm_probe()
231 		if (of_device_is_compatible(np, "ti,am33xx-ecap")) {  in ecap_pwm_probe()
232 			dev_warn(&pdev->dev, "Binding is obsolete.\n");  in ecap_pwm_probe()
233 			clk = devm_clk_get(pdev->dev.parent, "fck");  in ecap_pwm_probe()
238 		dev_err(&pdev->dev, "failed to get clock\n");  in ecap_pwm_probe()
242 	pc->clk_rate = clk_get_rate(clk);  in ecap_pwm_probe()
243 	if (!pc->clk_rate) {  in ecap_pwm_probe()
244 		dev_err(&pdev->dev, "failed to get clock rate\n");  in ecap_pwm_probe()
245 		return -EINVAL;  in ecap_pwm_probe()
248 	chip->ops = &ecap_pwm_ops;  in ecap_pwm_probe()
250 	pc->mmio_base = devm_platform_ioremap_resource(pdev, 0);  in ecap_pwm_probe()
251 	if (IS_ERR(pc->mmio_base))  in ecap_pwm_probe()
252 		return PTR_ERR(pc->mmio_base);  in ecap_pwm_probe()
254 	ret = devm_pwmchip_add(&pdev->dev, chip);  in ecap_pwm_probe()
256 		dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);  in ecap_pwm_probe()
261 	pm_runtime_enable(&pdev->dev);  in ecap_pwm_probe()
268 	pm_runtime_disable(&pdev->dev);  in ecap_pwm_remove()
276 	pc->ctx.ecctl2 = readw(pc->mmio_base + ECCTL2);  in ecap_pwm_save_context()
277 	pc->ctx.cap4 = readl(pc->mmio_base + CAP4);  in ecap_pwm_save_context()
278 	pc->ctx.cap3 = readl(pc->mmio_base + CAP3);  in ecap_pwm_save_context()
286 	writel(pc->ctx.cap3, pc->mmio_base + CAP3);  in ecap_pwm_restore_context()
287 	writel(pc->ctx.cap4, pc->mmio_base + CAP4);  in ecap_pwm_restore_context()
288 	writew(pc->ctx.ecctl2, pc->mmio_base + ECCTL2);  in ecap_pwm_restore_context()
294 	struct pwm_device *pwm = chip->pwms;  in ecap_pwm_suspend()  local
298 	/* Disable explicitly if PWM is running */  in ecap_pwm_suspend()
299 	if (pwm_is_enabled(pwm))  in ecap_pwm_suspend()
308 	struct pwm_device *pwm = chip->pwms;  in ecap_pwm_resume()  local
310 	/* Enable explicitly if PWM was running */  in ecap_pwm_resume()
311 	if (pwm_is_enabled(pwm))  in ecap_pwm_resume()
331 MODULE_DESCRIPTION("ECAP PWM driver");