1 // SPDX-License-Identifier: GPL-2.0-or-later
3  *  Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
4  *  JZ4740 platform PWM support
7  * - The .apply callback doesn't complete the currently running period before
15 #include <linux/mfd/ingenic-tcu.h>
20 #include <linux/pwm.h>
40 	/* Enable all TCU channels for PWM use by default except channels 0/1 */  in jz4740_pwm_can_use_chn()
41 	u32 pwm_channels_mask = GENMASK(jz->chip.npwm - 1, 2);  in jz4740_pwm_can_use_chn()
43 	device_property_read_u32(jz->chip.dev->parent,  in jz4740_pwm_can_use_chn()
44 				 "ingenic,pwm-channels-mask",  in jz4740_pwm_can_use_chn()
50 static int jz4740_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)  in jz4740_pwm_request()  argument
57 	if (!jz4740_pwm_can_use_chn(jz, pwm->hwpwm))  in jz4740_pwm_request()
58 		return -EBUSY;  in jz4740_pwm_request()
60 	snprintf(name, sizeof(name), "timer%u", pwm->hwpwm);  in jz4740_pwm_request()
62 	clk = clk_get(chip->dev, name);  in jz4740_pwm_request()
64 		dev_err(chip->dev, "error %pe: Failed to get clock\n", clk);  in jz4740_pwm_request()
74 	pwm_set_chip_data(pwm, clk);  in jz4740_pwm_request()
79 static void jz4740_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)  in jz4740_pwm_free()  argument
81 	struct clk *clk = pwm_get_chip_data(pwm);  in jz4740_pwm_free()
87 static int jz4740_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)  in jz4740_pwm_enable()  argument
91 	/* Enable PWM output */  in jz4740_pwm_enable()
92 	regmap_update_bits(jz->map, TCU_REG_TCSRc(pwm->hwpwm),  in jz4740_pwm_enable()
96 	regmap_write(jz->map, TCU_REG_TESR, BIT(pwm->hwpwm));  in jz4740_pwm_enable()
101 static void jz4740_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)  in jz4740_pwm_disable()  argument
109 	regmap_write(jz->map, TCU_REG_TDHRc(pwm->hwpwm), 0xffff);  in jz4740_pwm_disable()
110 	regmap_write(jz->map, TCU_REG_TDFRc(pwm->hwpwm), 0x0);  in jz4740_pwm_disable()
113 	 * Disable PWM output.  in jz4740_pwm_disable()
117 	regmap_update_bits(jz->map, TCU_REG_TCSRc(pwm->hwpwm),  in jz4740_pwm_disable()
121 	regmap_write(jz->map, TCU_REG_TECR, BIT(pwm->hwpwm));  in jz4740_pwm_disable()
124 static int jz4740_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,  in jz4740_pwm_apply()  argument
125 			    const struct pwm_state *state)  in jz4740_pwm_apply()  argument
127 	struct jz4740_pwm_chip *jz4740 = to_jz4740(pwm->chip);  in jz4740_pwm_apply()
129 	struct clk *clk = pwm_get_chip_data(pwm);  in jz4740_pwm_apply()
138 	do_div(tmp, state->period);  in jz4740_pwm_apply()
142 	 * -------------------  in jz4740_pwm_apply()
148 	 * round-down function (and won't have one for a while), but if it ever  in jz4740_pwm_apply()
149 	 * comes to light, a round-down function should be used instead.  in jz4740_pwm_apply()
153 		dev_err(chip->dev, "Unable to round rate: %ld", rate);  in jz4740_pwm_apply()
158 	tmp = (unsigned long long)rate * state->period;  in jz4740_pwm_apply()
163 	tmp = (unsigned long long)rate * state->duty_cycle;  in jz4740_pwm_apply()
168 		duty = period - 1;  in jz4740_pwm_apply()
170 	jz4740_pwm_disable(chip, pwm);  in jz4740_pwm_apply()
174 		dev_err(chip->dev, "Unable to set rate: %d", err);  in jz4740_pwm_apply()
179 	regmap_write(jz4740->map, TCU_REG_TCNTc(pwm->hwpwm), 0);  in jz4740_pwm_apply()
182 	regmap_write(jz4740->map, TCU_REG_TDHRc(pwm->hwpwm), duty);  in jz4740_pwm_apply()
185 	regmap_write(jz4740->map, TCU_REG_TDFRc(pwm->hwpwm), period);  in jz4740_pwm_apply()
188 	regmap_update_bits(jz4740->map, TCU_REG_TCSRc(pwm->hwpwm),  in jz4740_pwm_apply()
194 	 * The PWM starts in inactive state until the internal timer reaches the  in jz4740_pwm_apply()
195 	 * duty value, then becomes active until the timer reaches the period  in jz4740_pwm_apply()
196 	 * value. In theory, we should then use (period - duty) as the real duty  in jz4740_pwm_apply()
197 	 * value, as a high duty value would otherwise result in the PWM pin  in jz4740_pwm_apply()
200 	 * Here, we don't do that, and instead invert the polarity of the PWM  in jz4740_pwm_apply()
201 	 * when it is active. This trick makes the PWM start with its active  in jz4740_pwm_apply()
202 	 * state instead of its inactive state.  in jz4740_pwm_apply()
204 	if ((state->polarity == PWM_POLARITY_NORMAL) ^ state->enabled)  in jz4740_pwm_apply()
205 		regmap_update_bits(jz4740->map, TCU_REG_TCSRc(pwm->hwpwm),  in jz4740_pwm_apply()
208 		regmap_update_bits(jz4740->map, TCU_REG_TCSRc(pwm->hwpwm),  in jz4740_pwm_apply()
212 	if (state->enabled)  in jz4740_pwm_apply()
213 		jz4740_pwm_enable(chip, pwm);  in jz4740_pwm_apply()
227 	struct device *dev = &pdev->dev;  in jz4740_pwm_probe()
233 		return -EINVAL;  in jz4740_pwm_probe()
237 		return -ENOMEM;  in jz4740_pwm_probe()
239 	jz4740->map = device_node_to_regmap(dev->parent->of_node);  in jz4740_pwm_probe()
240 	if (IS_ERR(jz4740->map)) {  in jz4740_pwm_probe()
241 		dev_err(dev, "regmap not found: %ld\n", PTR_ERR(jz4740->map));  in jz4740_pwm_probe()
242 		return PTR_ERR(jz4740->map);  in jz4740_pwm_probe()
245 	jz4740->chip.dev = dev;  in jz4740_pwm_probe()
246 	jz4740->chip.ops = &jz4740_pwm_ops;  in jz4740_pwm_probe()
247 	jz4740->chip.npwm = info->num_pwms;  in jz4740_pwm_probe()
248 	jz4740->chip.base = -1;  in jz4740_pwm_probe()
249 	jz4740->chip.of_xlate = of_pwm_xlate_with_flags;  in jz4740_pwm_probe()
250 	jz4740->chip.of_pwm_n_cells = 3;  in jz4740_pwm_probe()
254 	return pwmchip_add(&jz4740->chip);  in jz4740_pwm_probe()
261 	return pwmchip_remove(&jz4740->chip);  in jz4740_pwm_remove()
274 	{ .compatible = "ingenic,jz4740-pwm", .data = &jz4740_soc_info },
275 	{ .compatible = "ingenic,jz4725b-pwm", .data = &jz4725b_soc_info },
283 		.name = "jz4740-pwm",
291 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
292 MODULE_DESCRIPTION("Ingenic JZ4740 PWM driver");
293 MODULE_ALIAS("platform:jz4740-pwm");