drivers/pwm/pwm-ti-ehrpwm.c - platform/external/u-boot - Gitiles

 // SPDX-License-Identifier: GPL-2.0+
 /*
  * EHRPWM PWM driver
  *
  * Copyright (C) 2020 Dario Binacchi <dariobin@libero.it>
  *
  * Based on Linux kernel drivers/pwm/pwm-tiehrpwm.c
  */

 #include <common.h>
 #include <clk.h>
 #include <div64.h>
 #include <dm.h>
 #include <dm/device_compat.h>
 #include <pwm.h>
 #include <asm/io.h>
 #include <linux/time.h>

 /* Time base module registers */
 #define TI_EHRPWM_TBCTL				0x00
 #define TI_EHRPWM_TBPRD				0x0A

 #define TI_EHRPWM_TBCTL_PRDLD_MASK		BIT(3)
 #define TI_EHRPWM_TBCTL_PRDLD_SHDW		0
 #define TI_EHRPWM_TBCTL_PRDLD_IMDT		BIT(3)
 #define TI_EHRPWM_TBCTL_CLKDIV_MASK		GENMASK(12, 7)
 #define TI_EHRPWM_TBCTL_CTRMODE_MASK		GENMASK(1, 0)
 #define TI_EHRPWM_TBCTL_CTRMODE_UP		0
 #define TI_EHRPWM_TBCTL_CTRMODE_DOWN		BIT(0)
 #define TI_EHRPWM_TBCTL_CTRMODE_UPDOWN		BIT(1)
 #define TI_EHRPWM_TBCTL_CTRMODE_FREEZE		GENMASK(1, 0)

 #define TI_EHRPWM_TBCTL_HSPCLKDIV_SHIFT		7
 #define TI_EHRPWM_TBCTL_CLKDIV_SHIFT		10

 #define TI_EHRPWM_CLKDIV_MAX			7
 #define TI_EHRPWM_HSPCLKDIV_MAX			7
 #define TI_EHRPWM_PERIOD_MAX			0xFFFF

 /* Counter compare module registers */
 #define TI_EHRPWM_CMPA				0x12
 #define TI_EHRPWM_CMPB				0x14

 /* Action qualifier module registers */
 #define TI_EHRPWM_AQCTLA			0x16
 #define TI_EHRPWM_AQCTLB			0x18
 #define TI_EHRPWM_AQSFRC			0x1A
 #define TI_EHRPWM_AQCSFRC			0x1C

 #define TI_EHRPWM_AQCTL_CBU_MASK		GENMASK(9, 8)
 #define TI_EHRPWM_AQCTL_CBU_FRCLOW		BIT(8)
 #define TI_EHRPWM_AQCTL_CBU_FRCHIGH		BIT(9)
 #define TI_EHRPWM_AQCTL_CBU_FRCTOGGLE		GENMASK(9, 8)
 #define TI_EHRPWM_AQCTL_CAU_MASK		GENMASK(5, 4)
 #define TI_EHRPWM_AQCTL_CAU_FRCLOW		BIT(4)
 #define TI_EHRPWM_AQCTL_CAU_FRCHIGH		BIT(5)
 #define TI_EHRPWM_AQCTL_CAU_FRCTOGGLE		GENMASK(5, 4)
 #define TI_EHRPWM_AQCTL_PRD_MASK		GENMASK(3, 2)
 #define TI_EHRPWM_AQCTL_PRD_FRCLOW		BIT(2)
 #define TI_EHRPWM_AQCTL_PRD_FRCHIGH		BIT(3)
 #define TI_EHRPWM_AQCTL_PRD_FRCTOGGLE		GENMASK(3, 2)
 #define TI_EHRPWM_AQCTL_ZRO_MASK		GENMASK(1, 0)
 #define TI_EHRPWM_AQCTL_ZRO_FRCLOW		BIT(0)
 #define TI_EHRPWM_AQCTL_ZRO_FRCHIGH		BIT(1)
 #define TI_EHRPWM_AQCTL_ZRO_FRCTOGGLE		GENMASK(1, 0)

 #define TI_EHRPWM_AQCTL_CHANA_POLNORMAL		(TI_EHRPWM_AQCTL_CAU_FRCLOW | \
 						 TI_EHRPWM_AQCTL_PRD_FRCHIGH | \
 						 TI_EHRPWM_AQCTL_ZRO_FRCHIGH)
 #define TI_EHRPWM_AQCTL_CHANA_POLINVERSED	(TI_EHRPWM_AQCTL_CAU_FRCHIGH | \
 						 TI_EHRPWM_AQCTL_PRD_FRCLOW | \
 						 TI_EHRPWM_AQCTL_ZRO_FRCLOW)
 #define TI_EHRPWM_AQCTL_CHANB_POLNORMAL		(TI_EHRPWM_AQCTL_CBU_FRCLOW | \
 						 TI_EHRPWM_AQCTL_PRD_FRCHIGH | \
 						 TI_EHRPWM_AQCTL_ZRO_FRCHIGH)
 #define TI_EHRPWM_AQCTL_CHANB_POLINVERSED	(TI_EHRPWM_AQCTL_CBU_FRCHIGH | \
 						 TI_EHRPWM_AQCTL_PRD_FRCLOW | \
 						 TI_EHRPWM_AQCTL_ZRO_FRCLOW)

 #define TI_EHRPWM_AQSFRC_RLDCSF_MASK		GENMASK(7, 6)
 #define TI_EHRPWM_AQSFRC_RLDCSF_ZRO		0
 #define TI_EHRPWM_AQSFRC_RLDCSF_PRD		BIT(6)
 #define TI_EHRPWM_AQSFRC_RLDCSF_ZROPRD		BIT(7)
 #define TI_EHRPWM_AQSFRC_RLDCSF_IMDT		GENMASK(7, 6)

 #define TI_EHRPWM_AQCSFRC_CSFB_MASK		GENMASK(3, 2)
 #define TI_EHRPWM_AQCSFRC_CSFB_FRCDIS		0
 #define TI_EHRPWM_AQCSFRC_CSFB_FRCLOW		BIT(2)
 #define TI_EHRPWM_AQCSFRC_CSFB_FRCHIGH		BIT(3)
 #define TI_EHRPWM_AQCSFRC_CSFB_DISSWFRC		GENMASK(3, 2)
 #define TI_EHRPWM_AQCSFRC_CSFA_MASK		GENMASK(1, 0)
 #define TI_EHRPWM_AQCSFRC_CSFA_FRCDIS		0
 #define TI_EHRPWM_AQCSFRC_CSFA_FRCLOW		BIT(0)
 #define TI_EHRPWM_AQCSFRC_CSFA_FRCHIGH		BIT(1)
 #define TI_EHRPWM_AQCSFRC_CSFA_DISSWFRC		GENMASK(1, 0)

 #define TI_EHRPWM_NUM_CHANNELS                  2

 struct ti_ehrpwm_priv {
 	fdt_addr_t regs;
 	u32 clk_rate;
 	struct clk tbclk;
 	unsigned long period_cycles[TI_EHRPWM_NUM_CHANNELS];
 	bool polarity_reversed[TI_EHRPWM_NUM_CHANNELS];
 };

 static void ti_ehrpwm_modify(u16 val, u16 mask, fdt_addr_t reg)
 {
 	unsigned short v;

 	v = readw(reg);
 	v &= ~mask;
 	v |= val & mask;
 	writew(v, reg);
 }

 static int ti_ehrpwm_set_invert(struct udevice *dev, uint channel,
 				bool polarity)
 {
 	struct ti_ehrpwm_priv *priv = dev_get_priv(dev);

 	if (channel >= TI_EHRPWM_NUM_CHANNELS)
 		return -ENOSPC;

 	/* Configuration of polarity in hardware delayed, do at enable */
 	priv->polarity_reversed[channel] = polarity;
 	return 0;
 }

 /**
  * set_prescale_div -	Set up the prescaler divider function
  * @rqst_prescaler:	prescaler value min
  * @prescale_div:	prescaler value set
  * @tb_clk_div:		Time Base Control prescaler bits
  */
 static int set_prescale_div(unsigned long rqst_prescaler, u16 *prescale_div,
 			    u16 *tb_clk_div)
 {
 	unsigned int clkdiv, hspclkdiv;

 	for (clkdiv = 0; clkdiv <= TI_EHRPWM_CLKDIV_MAX; clkdiv++) {
 		for (hspclkdiv = 0; hspclkdiv <= TI_EHRPWM_HSPCLKDIV_MAX;
 		     hspclkdiv++) {
 			/*
 			 * calculations for prescaler value :
 			 * prescale_div = HSPCLKDIVIDER * CLKDIVIDER.
 			 * HSPCLKDIVIDER =  2 ** hspclkdiv
 			 * CLKDIVIDER = (1),            if clkdiv == 0 *OR*
 			 *              (2 * clkdiv),   if clkdiv != 0
 			 *
 			 * Configure prescale_div value such that period
 			 * register value is less than 65535.
 			 */

 			*prescale_div = (1 << clkdiv) *
 				(hspclkdiv ? (hspclkdiv * 2) : 1);
 			if (*prescale_div > rqst_prescaler) {
 				*tb_clk_div =
 				    (clkdiv << TI_EHRPWM_TBCTL_CLKDIV_SHIFT) |
 				    (hspclkdiv <<
 				     TI_EHRPWM_TBCTL_HSPCLKDIV_SHIFT);
 				return 0;
 			}
 		}
 	}

 	return 1;
 }

 static void ti_ehrpwm_configure_polarity(struct udevice *dev, uint channel)
 {
 	struct ti_ehrpwm_priv *priv = dev_get_priv(dev);
 	u16 aqctl_val, aqctl_mask;
 	unsigned int aqctl_reg;

 	/*
 	 * Configure PWM output to HIGH/LOW level on counter
 	 * reaches compare register value and LOW/HIGH level
 	 * on counter value reaches period register value and
 	 * zero value on counter
 	 */
 	if (channel == 1) {
 		aqctl_reg = TI_EHRPWM_AQCTLB;
 		aqctl_mask = TI_EHRPWM_AQCTL_CBU_MASK;

 		if (priv->polarity_reversed[channel])
 			aqctl_val = TI_EHRPWM_AQCTL_CHANB_POLINVERSED;
 		else
 			aqctl_val = TI_EHRPWM_AQCTL_CHANB_POLNORMAL;
 	} else {
 		aqctl_reg = TI_EHRPWM_AQCTLA;
 		aqctl_mask = TI_EHRPWM_AQCTL_CAU_MASK;

 		if (priv->polarity_reversed[channel])
 			aqctl_val = TI_EHRPWM_AQCTL_CHANA_POLINVERSED;
 		else
 			aqctl_val = TI_EHRPWM_AQCTL_CHANA_POLNORMAL;
 	}

 	aqctl_mask |= TI_EHRPWM_AQCTL_PRD_MASK | TI_EHRPWM_AQCTL_ZRO_MASK;
 	ti_ehrpwm_modify(aqctl_val, aqctl_mask, priv->regs + aqctl_reg);
 }

 /*
  * period_ns = 10^9 * (ps_divval * period_cycles) / PWM_CLK_RATE
  * duty_ns   = 10^9 * (ps_divval * duty_cycles) / PWM_CLK_RATE
  */
 static int ti_ehrpwm_set_config(struct udevice *dev, uint channel,
 				uint period_ns, uint duty_ns)
 {
 	struct ti_ehrpwm_priv *priv = dev_get_priv(dev);
 	u32 period_cycles, duty_cycles;
 	u16 ps_divval, tb_divval;
 	unsigned int i, cmp_reg;
 	unsigned long long c;

 	if (channel >= TI_EHRPWM_NUM_CHANNELS)
 		return -ENOSPC;

 	if (period_ns > NSEC_PER_SEC)
 		return -ERANGE;

 	c = priv->clk_rate;
 	c = c * period_ns;
 	do_div(c, NSEC_PER_SEC);
 	period_cycles = (unsigned long)c;

 	if (period_cycles < 1) {
 		period_cycles = 1;
 		duty_cycles = 1;
 	} else {
 		c = priv->clk_rate;
 		c = c * duty_ns;
 		do_div(c, NSEC_PER_SEC);
 		duty_cycles = (unsigned long)c;
 	}

 	dev_dbg(dev, "channel=%d, period_ns=%d, duty_ns=%d\n",
 		channel, period_ns, duty_ns);

 	/*
 	 * Period values should be same for multiple PWM channels as IP uses
 	 * same period register for multiple channels.
 	 */
 	for (i = 0; i < TI_EHRPWM_NUM_CHANNELS; i++) {
 		if (priv->period_cycles[i] &&
 		    priv->period_cycles[i] != period_cycles) {
 			/*
 			 * Allow channel to reconfigure period if no other
 			 * channels being configured.
 			 */
 			if (i == channel)
 				continue;

 			dev_err(dev, "period value conflicts with channel %u\n",
 				i);
 			return -EINVAL;
 		}
 	}

 	priv->period_cycles[channel] = period_cycles;

 	/* Configure clock prescaler to support Low frequency PWM wave */
 	if (set_prescale_div(period_cycles / TI_EHRPWM_PERIOD_MAX, &ps_divval,
 			     &tb_divval)) {
 		dev_err(dev, "unsupported values\n");
 		return -EINVAL;
 	}

 	/* Update clock prescaler values */
 	ti_ehrpwm_modify(tb_divval, TI_EHRPWM_TBCTL_CLKDIV_MASK,
 			 priv->regs + TI_EHRPWM_TBCTL);

 	/* Update period & duty cycle with presacler division */
 	period_cycles = period_cycles / ps_divval;
 	duty_cycles = duty_cycles / ps_divval;

 	/* Configure shadow loading on Period register */
 	ti_ehrpwm_modify(TI_EHRPWM_TBCTL_PRDLD_SHDW, TI_EHRPWM_TBCTL_PRDLD_MASK,
 			 priv->regs + TI_EHRPWM_TBCTL);

 	writew(period_cycles, priv->regs + TI_EHRPWM_TBPRD);

 	/* Configure ehrpwm counter for up-count mode */
 	ti_ehrpwm_modify(TI_EHRPWM_TBCTL_CTRMODE_UP,
 			 TI_EHRPWM_TBCTL_CTRMODE_MASK,
 			 priv->regs + TI_EHRPWM_TBCTL);

 	if (channel == 1)
 		/* Channel 1 configured with compare B register */
 		cmp_reg = TI_EHRPWM_CMPB;
 	else
 		/* Channel 0 configured with compare A register */
 		cmp_reg = TI_EHRPWM_CMPA;

 	writew(duty_cycles, priv->regs + cmp_reg);
 	return 0;
 }

 static int ti_ehrpwm_disable(struct udevice *dev, uint channel)
 {
 	struct ti_ehrpwm_priv *priv = dev_get_priv(dev);
 	u16 aqcsfrc_val, aqcsfrc_mask;
 	int err;

 	if (channel >= TI_EHRPWM_NUM_CHANNELS)
 		return -ENOSPC;

 	/* Action Qualifier puts PWM output low forcefully */
 	if (channel) {
 		aqcsfrc_val = TI_EHRPWM_AQCSFRC_CSFB_FRCLOW;
 		aqcsfrc_mask = TI_EHRPWM_AQCSFRC_CSFB_MASK;
 	} else {
 		aqcsfrc_val = TI_EHRPWM_AQCSFRC_CSFA_FRCLOW;
 		aqcsfrc_mask = TI_EHRPWM_AQCSFRC_CSFA_MASK;
 	}

 	/* Update shadow register first before modifying active register */
 	ti_ehrpwm_modify(TI_EHRPWM_AQSFRC_RLDCSF_ZRO,
 			 TI_EHRPWM_AQSFRC_RLDCSF_MASK,
 			 priv->regs + TI_EHRPWM_AQSFRC);

 	ti_ehrpwm_modify(aqcsfrc_val, aqcsfrc_mask,
 			 priv->regs + TI_EHRPWM_AQCSFRC);

 	/*
 	 * Changes to immediate action on Action Qualifier. This puts
 	 * Action Qualifier control on PWM output from next TBCLK
 	 */
 	ti_ehrpwm_modify(TI_EHRPWM_AQSFRC_RLDCSF_IMDT,
 			 TI_EHRPWM_AQSFRC_RLDCSF_MASK,
 			 priv->regs + TI_EHRPWM_AQSFRC);

 	ti_ehrpwm_modify(aqcsfrc_val, aqcsfrc_mask,
 			 priv->regs + TI_EHRPWM_AQCSFRC);

 	/* Disabling TBCLK on PWM disable */
 	err = clk_disable(&priv->tbclk);
 	if (err) {
 		dev_err(dev, "failed to disable tbclk\n");
 		return err;
 	}

 	return 0;
 }

 static int ti_ehrpwm_enable(struct udevice *dev, uint channel)
 {
 	struct ti_ehrpwm_priv *priv = dev_get_priv(dev);
 	u16 aqcsfrc_val, aqcsfrc_mask;
 	int err;

 	if (channel >= TI_EHRPWM_NUM_CHANNELS)
 		return -ENOSPC;

 	/* Disabling Action Qualifier on PWM output */
 	if (channel) {
 		aqcsfrc_val = TI_EHRPWM_AQCSFRC_CSFB_FRCDIS;
 		aqcsfrc_mask = TI_EHRPWM_AQCSFRC_CSFB_MASK;
 	} else {
 		aqcsfrc_val = TI_EHRPWM_AQCSFRC_CSFA_FRCDIS;
 		aqcsfrc_mask = TI_EHRPWM_AQCSFRC_CSFA_MASK;
 	}

 	/* Changes to shadow mode */
 	ti_ehrpwm_modify(TI_EHRPWM_AQSFRC_RLDCSF_ZRO,
 			 TI_EHRPWM_AQSFRC_RLDCSF_MASK,
 			 priv->regs + TI_EHRPWM_AQSFRC);

 	ti_ehrpwm_modify(aqcsfrc_val, aqcsfrc_mask,
 			 priv->regs + TI_EHRPWM_AQCSFRC);

 	/* Channels polarity can be configured from action qualifier module */
 	ti_ehrpwm_configure_polarity(dev, channel);

 	err = clk_enable(&priv->tbclk);
 	if (err) {
 		dev_err(dev, "failed to enable tbclk\n");
 		return err;
 	}

 	return 0;
 }

 static int ti_ehrpwm_set_enable(struct udevice *dev, uint channel, bool enable)
 {
 	if (enable)
 		return ti_ehrpwm_enable(dev, channel);

 	return ti_ehrpwm_disable(dev, channel);
 }

 static int ti_ehrpwm_of_to_plat(struct udevice *dev)
 {
 	struct ti_ehrpwm_priv *priv = dev_get_priv(dev);

 	priv->regs = dev_read_addr(dev);
 	if (priv->regs == FDT_ADDR_T_NONE) {
 		dev_err(dev, "invalid address\n");
 		return -EINVAL;
 	}

 	dev_dbg(dev, "regs=0x%08lx\n", priv->regs);
 	return 0;
 }

 static int ti_ehrpwm_remove(struct udevice *dev)
 {
 	struct ti_ehrpwm_priv *priv = dev_get_priv(dev);

 	clk_release_all(&priv->tbclk, 1);
 	return 0;
 }

 static int ti_ehrpwm_probe(struct udevice *dev)
 {
 	struct ti_ehrpwm_priv *priv = dev_get_priv(dev);
 	struct clk clk;
 	int err;

 	err = clk_get_by_name(dev, "fck", &clk);
 	if (err) {
 		dev_err(dev, "failed to get clock\n");
 		return err;
 	}

 	priv->clk_rate = clk_get_rate(&clk);
 	if (IS_ERR_VALUE(priv->clk_rate) || !priv->clk_rate) {
 		dev_err(dev, "failed to get clock rate\n");
 		if (IS_ERR_VALUE(priv->clk_rate))
 			return priv->clk_rate;

 		return -EINVAL;
 	}

 	/* Acquire tbclk for Time Base EHRPWM submodule */
 	err = clk_get_by_name(dev, "tbclk", &priv->tbclk);
 	if (err) {
 		dev_err(dev, "failed to get tbclk clock\n");
 		return err;
 	}

 	return 0;
 }

 static const struct pwm_ops ti_ehrpwm_ops = {
 	.set_config = ti_ehrpwm_set_config,
 	.set_enable = ti_ehrpwm_set_enable,
 	.set_invert = ti_ehrpwm_set_invert,
 };

 static const struct udevice_id ti_ehrpwm_ids[] = {
 	{.compatible = "ti,am3352-ehrpwm"},
 	{.compatible = "ti,am33xx-ehrpwm"},
 	{}
 };

 U_BOOT_DRIVER(ti_ehrpwm) = {
 	.name = "ti_ehrpwm",
 	.id = UCLASS_PWM,
 	.of_match = ti_ehrpwm_ids,
 	.ops = &ti_ehrpwm_ops,
 	.of_to_plat = ti_ehrpwm_of_to_plat,
 	.probe = ti_ehrpwm_probe,
 	.remove = ti_ehrpwm_remove,
 	.priv_auto = sizeof(struct ti_ehrpwm_priv),
 };
	// SPDX-License-Identifier: GPL-2.0+
	/*
	* EHRPWM PWM driver
	*
	* Copyright (C) 2020 Dario Binacchi <dariobin@libero.it>
	*
	* Based on Linux kernel drivers/pwm/pwm-tiehrpwm.c
	*/

	#include <common.h>
	#include <clk.h>
	#include <div64.h>
	#include <dm.h>
	#include <dm/device_compat.h>
	#include <pwm.h>
	#include <asm/io.h>
	#include <linux/time.h>

	/* Time base module registers */
	#define TI_EHRPWM_TBCTL 0x00
	#define TI_EHRPWM_TBPRD 0x0A

	#define TI_EHRPWM_TBCTL_PRDLD_MASK BIT(3)
	#define TI_EHRPWM_TBCTL_PRDLD_SHDW 0
	#define TI_EHRPWM_TBCTL_PRDLD_IMDT BIT(3)
	#define TI_EHRPWM_TBCTL_CLKDIV_MASK GENMASK(12, 7)
	#define TI_EHRPWM_TBCTL_CTRMODE_MASK GENMASK(1, 0)
	#define TI_EHRPWM_TBCTL_CTRMODE_UP 0
	#define TI_EHRPWM_TBCTL_CTRMODE_DOWN BIT(0)
	#define TI_EHRPWM_TBCTL_CTRMODE_UPDOWN BIT(1)
	#define TI_EHRPWM_TBCTL_CTRMODE_FREEZE GENMASK(1, 0)

	#define TI_EHRPWM_TBCTL_HSPCLKDIV_SHIFT 7
	#define TI_EHRPWM_TBCTL_CLKDIV_SHIFT 10

	#define TI_EHRPWM_CLKDIV_MAX 7
	#define TI_EHRPWM_HSPCLKDIV_MAX 7
	#define TI_EHRPWM_PERIOD_MAX 0xFFFF

	/* Counter compare module registers */
	#define TI_EHRPWM_CMPA 0x12
	#define TI_EHRPWM_CMPB 0x14

	/* Action qualifier module registers */
	#define TI_EHRPWM_AQCTLA 0x16
	#define TI_EHRPWM_AQCTLB 0x18
	#define TI_EHRPWM_AQSFRC 0x1A
	#define TI_EHRPWM_AQCSFRC 0x1C

	#define TI_EHRPWM_AQCTL_CBU_MASK GENMASK(9, 8)
	#define TI_EHRPWM_AQCTL_CBU_FRCLOW BIT(8)
	#define TI_EHRPWM_AQCTL_CBU_FRCHIGH BIT(9)
	#define TI_EHRPWM_AQCTL_CBU_FRCTOGGLE GENMASK(9, 8)
	#define TI_EHRPWM_AQCTL_CAU_MASK GENMASK(5, 4)
	#define TI_EHRPWM_AQCTL_CAU_FRCLOW BIT(4)
	#define TI_EHRPWM_AQCTL_CAU_FRCHIGH BIT(5)
	#define TI_EHRPWM_AQCTL_CAU_FRCTOGGLE GENMASK(5, 4)
	#define TI_EHRPWM_AQCTL_PRD_MASK GENMASK(3, 2)
	#define TI_EHRPWM_AQCTL_PRD_FRCLOW BIT(2)
	#define TI_EHRPWM_AQCTL_PRD_FRCHIGH BIT(3)
	#define TI_EHRPWM_AQCTL_PRD_FRCTOGGLE GENMASK(3, 2)
	#define TI_EHRPWM_AQCTL_ZRO_MASK GENMASK(1, 0)
	#define TI_EHRPWM_AQCTL_ZRO_FRCLOW BIT(0)
	#define TI_EHRPWM_AQCTL_ZRO_FRCHIGH BIT(1)
	#define TI_EHRPWM_AQCTL_ZRO_FRCTOGGLE GENMASK(1, 0)

	#define TI_EHRPWM_AQCTL_CHANA_POLNORMAL (TI_EHRPWM_AQCTL_CAU_FRCLOW \| \
	TI_EHRPWM_AQCTL_PRD_FRCHIGH \| \
	TI_EHRPWM_AQCTL_ZRO_FRCHIGH)
	#define TI_EHRPWM_AQCTL_CHANA_POLINVERSED (TI_EHRPWM_AQCTL_CAU_FRCHIGH \| \
	TI_EHRPWM_AQCTL_PRD_FRCLOW \| \
	TI_EHRPWM_AQCTL_ZRO_FRCLOW)
	#define TI_EHRPWM_AQCTL_CHANB_POLNORMAL (TI_EHRPWM_AQCTL_CBU_FRCLOW \| \
	TI_EHRPWM_AQCTL_PRD_FRCHIGH \| \
	TI_EHRPWM_AQCTL_ZRO_FRCHIGH)
	#define TI_EHRPWM_AQCTL_CHANB_POLINVERSED (TI_EHRPWM_AQCTL_CBU_FRCHIGH \| \
	TI_EHRPWM_AQCTL_PRD_FRCLOW \| \
	TI_EHRPWM_AQCTL_ZRO_FRCLOW)

	#define TI_EHRPWM_AQSFRC_RLDCSF_MASK GENMASK(7, 6)
	#define TI_EHRPWM_AQSFRC_RLDCSF_ZRO 0
	#define TI_EHRPWM_AQSFRC_RLDCSF_PRD BIT(6)
	#define TI_EHRPWM_AQSFRC_RLDCSF_ZROPRD BIT(7)
	#define TI_EHRPWM_AQSFRC_RLDCSF_IMDT GENMASK(7, 6)

	#define TI_EHRPWM_AQCSFRC_CSFB_MASK GENMASK(3, 2)
	#define TI_EHRPWM_AQCSFRC_CSFB_FRCDIS 0
	#define TI_EHRPWM_AQCSFRC_CSFB_FRCLOW BIT(2)
	#define TI_EHRPWM_AQCSFRC_CSFB_FRCHIGH BIT(3)
	#define TI_EHRPWM_AQCSFRC_CSFB_DISSWFRC GENMASK(3, 2)
	#define TI_EHRPWM_AQCSFRC_CSFA_MASK GENMASK(1, 0)
	#define TI_EHRPWM_AQCSFRC_CSFA_FRCDIS 0
	#define TI_EHRPWM_AQCSFRC_CSFA_FRCLOW BIT(0)
	#define TI_EHRPWM_AQCSFRC_CSFA_FRCHIGH BIT(1)
	#define TI_EHRPWM_AQCSFRC_CSFA_DISSWFRC GENMASK(1, 0)

	#define TI_EHRPWM_NUM_CHANNELS 2

	struct ti_ehrpwm_priv {
	fdt_addr_t regs;
	u32 clk_rate;
	struct clk tbclk;
	unsigned long period_cycles[TI_EHRPWM_NUM_CHANNELS];
	bool polarity_reversed[TI_EHRPWM_NUM_CHANNELS];
	};

	static void ti_ehrpwm_modify(u16 val, u16 mask, fdt_addr_t reg)
	{
	unsigned short v;

	v = readw(reg);
	v &= ~mask;
	v \|= val & mask;
	writew(v, reg);
	}

	static int ti_ehrpwm_set_invert(struct udevice *dev, uint channel,
	bool polarity)
	{
	struct ti_ehrpwm_priv *priv = dev_get_priv(dev);

	if (channel >= TI_EHRPWM_NUM_CHANNELS)
	return -ENOSPC;

	/* Configuration of polarity in hardware delayed, do at enable */
	priv->polarity_reversed[channel] = polarity;
	return 0;
	}

	/**
	* set_prescale_div - Set up the prescaler divider function
	* @rqst_prescaler: prescaler value min
	* @prescale_div: prescaler value set
	* @tb_clk_div: Time Base Control prescaler bits
	*/
	static int set_prescale_div(unsigned long rqst_prescaler, u16 *prescale_div,
	u16 *tb_clk_div)
	{
	unsigned int clkdiv, hspclkdiv;

	for (clkdiv = 0; clkdiv <= TI_EHRPWM_CLKDIV_MAX; clkdiv++) {
	for (hspclkdiv = 0; hspclkdiv <= TI_EHRPWM_HSPCLKDIV_MAX;
	hspclkdiv++) {
	/*
	* calculations for prescaler value :
	* prescale_div = HSPCLKDIVIDER * CLKDIVIDER.
	* HSPCLKDIVIDER = 2 ** hspclkdiv
	* CLKDIVIDER = (1), if clkdiv == 0 OR
	* (2 * clkdiv), if clkdiv != 0
	*
	* Configure prescale_div value such that period
	* register value is less than 65535.
	*/

	prescale_div = (1 << clkdiv)
	(hspclkdiv ? (hspclkdiv * 2) : 1);
	if (*prescale_div > rqst_prescaler) {
	*tb_clk_div =
	(clkdiv << TI_EHRPWM_TBCTL_CLKDIV_SHIFT) \|
	(hspclkdiv <<
	TI_EHRPWM_TBCTL_HSPCLKDIV_SHIFT);
	return 0;
	}
	}
	}

	return 1;
	}

	static void ti_ehrpwm_configure_polarity(struct udevice *dev, uint channel)
	{
	struct ti_ehrpwm_priv *priv = dev_get_priv(dev);
	u16 aqctl_val, aqctl_mask;
	unsigned int aqctl_reg;

	/*
	* Configure PWM output to HIGH/LOW level on counter
	* reaches compare register value and LOW/HIGH level
	* on counter value reaches period register value and
	* zero value on counter
	*/
	if (channel == 1) {
	aqctl_reg = TI_EHRPWM_AQCTLB;
	aqctl_mask = TI_EHRPWM_AQCTL_CBU_MASK;

	if (priv->polarity_reversed[channel])
	aqctl_val = TI_EHRPWM_AQCTL_CHANB_POLINVERSED;
	else
	aqctl_val = TI_EHRPWM_AQCTL_CHANB_POLNORMAL;
	} else {
	aqctl_reg = TI_EHRPWM_AQCTLA;
	aqctl_mask = TI_EHRPWM_AQCTL_CAU_MASK;

	if (priv->polarity_reversed[channel])
	aqctl_val = TI_EHRPWM_AQCTL_CHANA_POLINVERSED;
	else
	aqctl_val = TI_EHRPWM_AQCTL_CHANA_POLNORMAL;
	}

	aqctl_mask \|= TI_EHRPWM_AQCTL_PRD_MASK \| TI_EHRPWM_AQCTL_ZRO_MASK;
	ti_ehrpwm_modify(aqctl_val, aqctl_mask, priv->regs + aqctl_reg);
	}

	/*
	* period_ns = 10^9 * (ps_divval * period_cycles) / PWM_CLK_RATE
	* duty_ns = 10^9 * (ps_divval * duty_cycles) / PWM_CLK_RATE
	*/
	static int ti_ehrpwm_set_config(struct udevice *dev, uint channel,
	uint period_ns, uint duty_ns)
	{
	struct ti_ehrpwm_priv *priv = dev_get_priv(dev);
	u32 period_cycles, duty_cycles;
	u16 ps_divval, tb_divval;
	unsigned int i, cmp_reg;
	unsigned long long c;

	if (channel >= TI_EHRPWM_NUM_CHANNELS)
	return -ENOSPC;

	if (period_ns > NSEC_PER_SEC)
	return -ERANGE;

	c = priv->clk_rate;
	c = c * period_ns;
	do_div(c, NSEC_PER_SEC);
	period_cycles = (unsigned long)c;

	if (period_cycles < 1) {
	period_cycles = 1;
	duty_cycles = 1;
	} else {
	c = priv->clk_rate;
	c = c * duty_ns;
	do_div(c, NSEC_PER_SEC);
	duty_cycles = (unsigned long)c;
	}

	dev_dbg(dev, "channel=%d, period_ns=%d, duty_ns=%d\n",
	channel, period_ns, duty_ns);

	/*
	* Period values should be same for multiple PWM channels as IP uses
	* same period register for multiple channels.
	*/
	for (i = 0; i < TI_EHRPWM_NUM_CHANNELS; i++) {
	if (priv->period_cycles[i] &&
	priv->period_cycles[i] != period_cycles) {
	/*
	* Allow channel to reconfigure period if no other
	* channels being configured.
	*/
	if (i == channel)
	continue;

	dev_err(dev, "period value conflicts with channel %u\n",
	i);
	return -EINVAL;
	}
	}

	priv->period_cycles[channel] = period_cycles;

	/* Configure clock prescaler to support Low frequency PWM wave */
	if (set_prescale_div(period_cycles / TI_EHRPWM_PERIOD_MAX, &ps_divval,
	&tb_divval)) {
	dev_err(dev, "unsupported values\n");
	return -EINVAL;
	}

	/* Update clock prescaler values */
	ti_ehrpwm_modify(tb_divval, TI_EHRPWM_TBCTL_CLKDIV_MASK,
	priv->regs + TI_EHRPWM_TBCTL);

	/* Update period & duty cycle with presacler division */
	period_cycles = period_cycles / ps_divval;
	duty_cycles = duty_cycles / ps_divval;

	/* Configure shadow loading on Period register */
	ti_ehrpwm_modify(TI_EHRPWM_TBCTL_PRDLD_SHDW, TI_EHRPWM_TBCTL_PRDLD_MASK,
	priv->regs + TI_EHRPWM_TBCTL);

	writew(period_cycles, priv->regs + TI_EHRPWM_TBPRD);

	/* Configure ehrpwm counter for up-count mode */
	ti_ehrpwm_modify(TI_EHRPWM_TBCTL_CTRMODE_UP,
	TI_EHRPWM_TBCTL_CTRMODE_MASK,
	priv->regs + TI_EHRPWM_TBCTL);

	if (channel == 1)
	/* Channel 1 configured with compare B register */
	cmp_reg = TI_EHRPWM_CMPB;
	else
	/* Channel 0 configured with compare A register */
	cmp_reg = TI_EHRPWM_CMPA;

	writew(duty_cycles, priv->regs + cmp_reg);
	return 0;
	}

	static int ti_ehrpwm_disable(struct udevice *dev, uint channel)
	{
	struct ti_ehrpwm_priv *priv = dev_get_priv(dev);
	u16 aqcsfrc_val, aqcsfrc_mask;
	int err;

	if (channel >= TI_EHRPWM_NUM_CHANNELS)
	return -ENOSPC;

	/* Action Qualifier puts PWM output low forcefully */
	if (channel) {
	aqcsfrc_val = TI_EHRPWM_AQCSFRC_CSFB_FRCLOW;
	aqcsfrc_mask = TI_EHRPWM_AQCSFRC_CSFB_MASK;
	} else {
	aqcsfrc_val = TI_EHRPWM_AQCSFRC_CSFA_FRCLOW;
	aqcsfrc_mask = TI_EHRPWM_AQCSFRC_CSFA_MASK;
	}

	/* Update shadow register first before modifying active register */
	ti_ehrpwm_modify(TI_EHRPWM_AQSFRC_RLDCSF_ZRO,
	TI_EHRPWM_AQSFRC_RLDCSF_MASK,
	priv->regs + TI_EHRPWM_AQSFRC);

	ti_ehrpwm_modify(aqcsfrc_val, aqcsfrc_mask,
	priv->regs + TI_EHRPWM_AQCSFRC);

	/*
	* Changes to immediate action on Action Qualifier. This puts
	* Action Qualifier control on PWM output from next TBCLK
	*/
	ti_ehrpwm_modify(TI_EHRPWM_AQSFRC_RLDCSF_IMDT,
	TI_EHRPWM_AQSFRC_RLDCSF_MASK,
	priv->regs + TI_EHRPWM_AQSFRC);

	ti_ehrpwm_modify(aqcsfrc_val, aqcsfrc_mask,
	priv->regs + TI_EHRPWM_AQCSFRC);

	/* Disabling TBCLK on PWM disable */
	err = clk_disable(&priv->tbclk);
	if (err) {
	dev_err(dev, "failed to disable tbclk\n");
	return err;
	}

	return 0;
	}

	static int ti_ehrpwm_enable(struct udevice *dev, uint channel)
	{
	struct ti_ehrpwm_priv *priv = dev_get_priv(dev);
	u16 aqcsfrc_val, aqcsfrc_mask;
	int err;

	if (channel >= TI_EHRPWM_NUM_CHANNELS)
	return -ENOSPC;

	/* Disabling Action Qualifier on PWM output */
	if (channel) {
	aqcsfrc_val = TI_EHRPWM_AQCSFRC_CSFB_FRCDIS;
	aqcsfrc_mask = TI_EHRPWM_AQCSFRC_CSFB_MASK;
	} else {
	aqcsfrc_val = TI_EHRPWM_AQCSFRC_CSFA_FRCDIS;
	aqcsfrc_mask = TI_EHRPWM_AQCSFRC_CSFA_MASK;
	}

	/* Changes to shadow mode */
	ti_ehrpwm_modify(TI_EHRPWM_AQSFRC_RLDCSF_ZRO,
	TI_EHRPWM_AQSFRC_RLDCSF_MASK,
	priv->regs + TI_EHRPWM_AQSFRC);

	ti_ehrpwm_modify(aqcsfrc_val, aqcsfrc_mask,
	priv->regs + TI_EHRPWM_AQCSFRC);

	/* Channels polarity can be configured from action qualifier module */
	ti_ehrpwm_configure_polarity(dev, channel);

	err = clk_enable(&priv->tbclk);
	if (err) {
	dev_err(dev, "failed to enable tbclk\n");
	return err;
	}

	return 0;
	}

	static int ti_ehrpwm_set_enable(struct udevice *dev, uint channel, bool enable)
	{
	if (enable)
	return ti_ehrpwm_enable(dev, channel);

	return ti_ehrpwm_disable(dev, channel);
	}

	static int ti_ehrpwm_of_to_plat(struct udevice *dev)
	{
	struct ti_ehrpwm_priv *priv = dev_get_priv(dev);

	priv->regs = dev_read_addr(dev);
	if (priv->regs == FDT_ADDR_T_NONE) {
	dev_err(dev, "invalid address\n");
	return -EINVAL;
	}

	dev_dbg(dev, "regs=0x%08lx\n", priv->regs);
	return 0;
	}

	static int ti_ehrpwm_remove(struct udevice *dev)
	{
	struct ti_ehrpwm_priv *priv = dev_get_priv(dev);

	clk_release_all(&priv->tbclk, 1);
	return 0;
	}

	static int ti_ehrpwm_probe(struct udevice *dev)
	{
	struct ti_ehrpwm_priv *priv = dev_get_priv(dev);
	struct clk clk;
	int err;

	err = clk_get_by_name(dev, "fck", &clk);
	if (err) {
	dev_err(dev, "failed to get clock\n");
	return err;
	}

	priv->clk_rate = clk_get_rate(&clk);
	if (IS_ERR_VALUE(priv->clk_rate) \|\| !priv->clk_rate) {
	dev_err(dev, "failed to get clock rate\n");
	if (IS_ERR_VALUE(priv->clk_rate))
	return priv->clk_rate;

	return -EINVAL;
	}

	/* Acquire tbclk for Time Base EHRPWM submodule */
	err = clk_get_by_name(dev, "tbclk", &priv->tbclk);
	if (err) {
	dev_err(dev, "failed to get tbclk clock\n");
	return err;
	}

	return 0;
	}

	static const struct pwm_ops ti_ehrpwm_ops = {
	.set_config = ti_ehrpwm_set_config,
	.set_enable = ti_ehrpwm_set_enable,
	.set_invert = ti_ehrpwm_set_invert,
	};

	static const struct udevice_id ti_ehrpwm_ids[] = {
	{.compatible = "ti,am3352-ehrpwm"},
	{.compatible = "ti,am33xx-ehrpwm"},
	{}
	};

	U_BOOT_DRIVER(ti_ehrpwm) = {
	.name = "ti_ehrpwm",
	.id = UCLASS_PWM,
	.of_match = ti_ehrpwm_ids,
	.ops = &ti_ehrpwm_ops,
	.of_to_plat = ti_ehrpwm_of_to_plat,
	.probe = ti_ehrpwm_probe,
	.remove = ti_ehrpwm_remove,
	.priv_auto = sizeof(struct ti_ehrpwm_priv),
	};