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  • // SPDX-License-Identifier: GPL-2.0+
    /*
     * Copyright (c) 2017-2018 Vasily Khoruzhick <anarsoul@gmail.com>
     */
    
    #include <common.h>
    #include <div64.h>
    #include <dm.h>
    #include <pwm.h>
    #include <regmap.h>
    #include <syscon.h>
    #include <asm/io.h>
    #include <asm/arch/pwm.h>
    #include <asm/arch/gpio.h>
    #include <power/regulator.h>
    
    DECLARE_GLOBAL_DATA_PTR;
    
    #define OSC_24MHZ 24000000
    
    struct sunxi_pwm_priv {
    	struct sunxi_pwm *regs;
    	bool invert;
    	u32 prescaler;
    };
    
    static const u32 prescaler_table[] = {
    	120,	/* 0000 */
    	180,	/* 0001 */
    	240,	/* 0010 */
    	360,	/* 0011 */
    	480,	/* 0100 */
    	0,	/* 0101 */
    	0,	/* 0110 */
    	0,	/* 0111 */
    	12000,	/* 1000 */
    	24000,	/* 1001 */
    	36000,	/* 1010 */
    	48000,	/* 1011 */
    	72000,	/* 1100 */
    	0,	/* 1101 */
    	0,	/* 1110 */
    	1,	/* 1111 */
    };
    
    static int sunxi_pwm_config_pinmux(void)
    {
    #ifdef CONFIG_MACH_SUN50I
    	sunxi_gpio_set_cfgpin(SUNXI_GPD(22), SUNXI_GPD_PWM);
    #endif
    	return 0;
    }
    
    static int sunxi_pwm_set_invert(struct udevice *dev, uint channel,
    				bool polarity)
    {
    	struct sunxi_pwm_priv *priv = dev_get_priv(dev);
    
    	debug("%s: polarity=%u\n", __func__, polarity);
    	priv->invert = polarity;
    
    	return 0;
    }
    
    static int sunxi_pwm_set_config(struct udevice *dev, uint channel,
    				uint period_ns, uint duty_ns)
    {
    	struct sunxi_pwm_priv *priv = dev_get_priv(dev);
    	struct sunxi_pwm *regs = priv->regs;
    	int prescaler;
    	u32 v, period = 0, duty;
    	u64 scaled_freq = 0;
    	const u32 nsecs_per_sec = 1000000000U;
    
    	debug("%s: period_ns=%u, duty_ns=%u\n", __func__, period_ns, duty_ns);
    
    	for (prescaler = 0; prescaler < SUNXI_PWM_CTRL_PRESCALE0_MASK;
    	     prescaler++) {
    		if (!prescaler_table[prescaler])
    			continue;
    		scaled_freq = lldiv(OSC_24MHZ, prescaler_table[prescaler]);
    		period = lldiv(scaled_freq * period_ns, nsecs_per_sec);
    		if (period - 1 <= SUNXI_PWM_CH0_PERIOD_MAX)
    			break;
    	}
    
    	if (period - 1 > SUNXI_PWM_CH0_PERIOD_MAX) {
    		debug("%s: failed to find prescaler value\n", __func__);
    		return -EINVAL;
    	}
    
    	duty = lldiv(scaled_freq * duty_ns, nsecs_per_sec);
    
    	if (priv->prescaler != prescaler) {
    		/* Mask clock to update prescaler */
    		v = readl(&regs->ctrl);
    		v &= ~SUNXI_PWM_CTRL_CLK_GATE;
    		writel(v, &regs->ctrl);
    		v &= ~SUNXI_PWM_CTRL_PRESCALE0_MASK;
    		v |= (priv->prescaler & SUNXI_PWM_CTRL_PRESCALE0_MASK);
    		writel(v, &regs->ctrl);
    		v |= SUNXI_PWM_CTRL_CLK_GATE;
    		writel(v, &regs->ctrl);
    		priv->prescaler = prescaler;
    	}
    
    	writel(SUNXI_PWM_CH0_PERIOD_PRD(period) |
    	       SUNXI_PWM_CH0_PERIOD_DUTY(duty), &regs->ch0_period);
    
    	debug("%s: prescaler: %d, period: %d, duty: %d\n",
    	      __func__, priv->prescaler,
    	      period, duty);
    
    	return 0;
    }
    
    static int sunxi_pwm_set_enable(struct udevice *dev, uint channel, bool enable)
    {
    	struct sunxi_pwm_priv *priv = dev_get_priv(dev);
    	struct sunxi_pwm *regs = priv->regs;
    	u32 v;
    
    	debug("%s: Enable '%s'\n", __func__, dev->name);
    
    	v = readl(&regs->ctrl);
    	if (!enable) {
    		v &= ~SUNXI_PWM_CTRL_ENABLE0;
    		writel(v, &regs->ctrl);
    		return 0;
    	}
    
    	sunxi_pwm_config_pinmux();
    
    	if (priv->invert)
    		v &= ~SUNXI_PWM_CTRL_CH0_ACT_STA;
    	else
    		v |= SUNXI_PWM_CTRL_CH0_ACT_STA;
    	v |= SUNXI_PWM_CTRL_ENABLE0;
    	writel(v, &regs->ctrl);
    
    	return 0;
    }
    
    static int sunxi_pwm_ofdata_to_platdata(struct udevice *dev)
    {
    	struct sunxi_pwm_priv *priv = dev_get_priv(dev);
    
    	priv->regs = (struct sunxi_pwm *)devfdt_get_addr(dev);
    
    	return 0;
    }
    
    static int sunxi_pwm_probe(struct udevice *dev)
    {
    	return 0;
    }
    
    static const struct pwm_ops sunxi_pwm_ops = {
    	.set_invert	= sunxi_pwm_set_invert,
    	.set_config	= sunxi_pwm_set_config,
    	.set_enable	= sunxi_pwm_set_enable,
    };
    
    static const struct udevice_id sunxi_pwm_ids[] = {
    	{ .compatible = "allwinner,sun5i-a13-pwm" },
    	{ .compatible = "allwinner,sun50i-a64-pwm" },
    	{ }
    };
    
    U_BOOT_DRIVER(sunxi_pwm) = {
    	.name	= "sunxi_pwm",
    	.id	= UCLASS_PWM,
    	.of_match = sunxi_pwm_ids,
    	.ops	= &sunxi_pwm_ops,
    	.ofdata_to_platdata	= sunxi_pwm_ofdata_to_platdata,
    	.probe		= sunxi_pwm_probe,
    	.priv_auto_alloc_size	= sizeof(struct sunxi_pwm_priv),
    };