1 // SPDX-License-Identifier: GPL-2.0-only
3  * Toshiba Visconti pulse-width-modulation controller driver
5  * Copyright (c) 2020 - 2021 TOSHIBA CORPORATION
6  * Copyright (c) 2020 - 2021 Toshiba Electronic Devices & Storage Corporation
11  * - The fixed input clock is running at 1 MHz and is divided by either 1,
13  * - When the settings of the PWM are modified, the new values are shadowed
15  *   running period is completed. This way the hardware switches atomically
17  * - Disabling the hardware completes the currently running period and keeps
26 #include <linux/pwm.h>
46 static int visconti_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,  in visconti_pwm_apply()  argument
50 	u32 period, duty_cycle, pwmc0;  in visconti_pwm_apply()  local
52 	if (!state->enabled) {  in visconti_pwm_apply()
53 		writel(0, priv->base + PIPGM_PCSR(pwm->hwpwm));  in visconti_pwm_apply()
58 	 * The biggest period the hardware can provide is  in visconti_pwm_apply()
63 	if (state->period > (0xffff << 3) * 1000)  in visconti_pwm_apply()
64 		period = (0xffff << 3) * 1000;  in visconti_pwm_apply()
66 		period = state->period;  in visconti_pwm_apply()
68 	if (state->duty_cycle > period)  in visconti_pwm_apply()
69 		duty_cycle = period;  in visconti_pwm_apply()
71 		duty_cycle = state->duty_cycle;  in visconti_pwm_apply()
78 	period /= 1000;  in visconti_pwm_apply()
81 	if (!period)  in visconti_pwm_apply()
82 		return -ERANGE;  in visconti_pwm_apply()
87 	 * the smallest possible one. As period is at most 0xffff << 3, pwmc0 is  in visconti_pwm_apply()
90 	pwmc0 = fls(period >> 16);  in visconti_pwm_apply()
92 		return -EINVAL;  in visconti_pwm_apply()
94 	period >>= pwmc0;  in visconti_pwm_apply()
97 	if (state->polarity == PWM_POLARITY_INVERSED)  in visconti_pwm_apply()
99 	writel(pwmc0, priv->base + PIPGM_PWMC(pwm->hwpwm));  in visconti_pwm_apply()
100 	writel(duty_cycle, priv->base + PIPGM_PDUT(pwm->hwpwm));  in visconti_pwm_apply()
101 	writel(period, priv->base + PIPGM_PCSR(pwm->hwpwm));  in visconti_pwm_apply()
106 static int visconti_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,  in visconti_pwm_get_state()  argument
110 	u32 period, duty, pwmc0, pwmc0_clk;  in visconti_pwm_get_state()  local
112 	period = readl(priv->base + PIPGM_PCSR(pwm->hwpwm));  in visconti_pwm_get_state()
113 	duty = readl(priv->base + PIPGM_PDUT(pwm->hwpwm));  in visconti_pwm_get_state()
114 	pwmc0 = readl(priv->base + PIPGM_PWMC(pwm->hwpwm));  in visconti_pwm_get_state()
117 	state->period = (period << pwmc0_clk) * NSEC_PER_USEC;  in visconti_pwm_get_state()
118 	state->duty_cycle = (duty << pwmc0_clk) * NSEC_PER_USEC;  in visconti_pwm_get_state()
120 		state->polarity = PWM_POLARITY_INVERSED;  in visconti_pwm_get_state()
122 		state->polarity = PWM_POLARITY_NORMAL;  in visconti_pwm_get_state()
124 	state->enabled = true;  in visconti_pwm_get_state()
137 	struct device *dev = &pdev->dev;  in visconti_pwm_probe()
143 		return -ENOMEM;  in visconti_pwm_probe()
145 	priv->base = devm_platform_ioremap_resource(pdev, 0);  in visconti_pwm_probe()
146 	if (IS_ERR(priv->base))  in visconti_pwm_probe()
147 		return PTR_ERR(priv->base);  in visconti_pwm_probe()
149 	priv->chip.dev = dev;  in visconti_pwm_probe()
150 	priv->chip.ops = &visconti_pwm_ops;  in visconti_pwm_probe()
151 	priv->chip.npwm = 4;  in visconti_pwm_probe()
153 	ret = devm_pwmchip_add(&pdev->dev, &priv->chip);  in visconti_pwm_probe()
155 		return dev_err_probe(&pdev->dev, ret, "Cannot register visconti PWM\n");  in visconti_pwm_probe()
161 	{ .compatible = "toshiba,visconti-pwm", },
168 		.name = "pwm-visconti",
177 MODULE_ALIAS("platform:pwm-visconti");