Re: [PATCH 02/11] pwm: atmel-tcb: switch to new binding

[Alexandre Belloni <alexandre.belloni@bootlin.com>]

Hi,

Note that this patch was not supposed to be sent right now.

On 06/04/2020 10:55:49+0200, Kamel Bouhara wrote:
> From: Alexandre Belloni <alexandre.belloni@free-electrons.com>
> 
> The PWM is now a subnode of the used TCB. This is cleaner and it mainly
> allows to stop wasting TCB channels when only 2 or 4 PWMs are used.
> 
> This also removes the atmel_tclib dependency
> 
> Cc: Thierry Reding <thierry.reding@gmail.com>
> Cc: linux-pwm@vger.kernel.org
> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
> ---
>  drivers/pwm/Kconfig         |   3 +-
>  drivers/pwm/pwm-atmel-tcb.c | 241 ++++++++++++++++++++----------------
>  2 files changed, 137 insertions(+), 107 deletions(-)
> 
> diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
> index 30190beeb6e9..1cf5a5d672c8 100644
> --- a/drivers/pwm/Kconfig
> +++ b/drivers/pwm/Kconfig
> @@ -65,7 +65,8 @@ config PWM_ATMEL_HLCDC_PWM
>  
>  config PWM_ATMEL_TCB
>  	tristate "Atmel TC Block PWM support"
> -	depends on ATMEL_TCLIB && OF
> +	depends on OF
> +	select REGMAP_MMIO
>  	help
>  	  Generic PWM framework driver for Atmel Timer Counter Block.
>  
> diff --git a/drivers/pwm/pwm-atmel-tcb.c b/drivers/pwm/pwm-atmel-tcb.c
> index 85c53701958c..82edb44fbbd8 100644
> --- a/drivers/pwm/pwm-atmel-tcb.c
> +++ b/drivers/pwm/pwm-atmel-tcb.c
> @@ -16,13 +16,16 @@
>  #include <linux/err.h>
>  #include <linux/ioport.h>
>  #include <linux/io.h>
> +#include <linux/mfd/syscon.h>
>  #include <linux/platform_device.h>
>  #include <linux/pwm.h>
>  #include <linux/of_device.h>
> +#include <linux/of_irq.h>
> +#include <linux/regmap.h>
>  #include <linux/slab.h>
>  #include <soc/at91/atmel_tcb.h>
>  
> -#define NPWM	6
> +#define NPWM	2
>  
>  #define ATMEL_TC_ACMR_MASK	(ATMEL_TC_ACPA | ATMEL_TC_ACPC |	\
>  				 ATMEL_TC_AEEVT | ATMEL_TC_ASWTRG)
> @@ -48,11 +51,17 @@ struct atmel_tcb_channel {
>  struct atmel_tcb_pwm_chip {
>  	struct pwm_chip chip;
>  	spinlock_t lock;
> -	struct atmel_tc *tc;
> +	u8 channel;
> +	u8 width;
> +	struct regmap *regmap;
> +	struct clk *clk;
> +	struct clk *slow_clk;
>  	struct atmel_tcb_pwm_device *pwms[NPWM];
> -	struct atmel_tcb_channel bkup[NPWM / 2];
> +	struct atmel_tcb_channel bkup;
>  };
>  
> +const u8 atmel_tcb_divisors[] = { 2, 8, 32, 128, 0, };
> +
>  static inline struct atmel_tcb_pwm_chip *to_tcb_chip(struct pwm_chip *chip)
>  {
>  	return container_of(chip, struct atmel_tcb_pwm_chip, chip);
> @@ -74,10 +83,6 @@ static int atmel_tcb_pwm_request(struct pwm_chip *chip,
>  {
>  	struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip);
>  	struct atmel_tcb_pwm_device *tcbpwm;
> -	struct atmel_tc *tc = tcbpwmc->tc;
> -	void __iomem *regs = tc->regs;
> -	unsigned group = pwm->hwpwm / 2;
> -	unsigned index = pwm->hwpwm % 2;
>  	unsigned cmr;
>  	int ret;
>  
> @@ -85,7 +90,7 @@ static int atmel_tcb_pwm_request(struct pwm_chip *chip,
>  	if (!tcbpwm)
>  		return -ENOMEM;
>  
> -	ret = clk_prepare_enable(tc->clk[group]);
> +	ret = clk_prepare_enable(tcbpwmc->clk);
>  	if (ret) {
>  		devm_kfree(chip->dev, tcbpwm);
>  		return ret;
> @@ -98,28 +103,31 @@ static int atmel_tcb_pwm_request(struct pwm_chip *chip,
>  	tcbpwm->div = 0;
>  
>  	spin_lock(&tcbpwmc->lock);
> -	cmr = __raw_readl(regs + ATMEL_TC_REG(group, CMR));
> +	regmap_read(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CMR), &cmr);
>  	/*
>  	 * Get init config from Timer Counter registers if
>  	 * Timer Counter is already configured as a PWM generator.
>  	 */
>  	if (cmr & ATMEL_TC_WAVE) {
> -		if (index == 0)
> -			tcbpwm->duty =
> -				__raw_readl(regs + ATMEL_TC_REG(group, RA));
> +		if (pwm->hwpwm == 0)
> +			regmap_read(tcbpwmc->regmap,
> +				    ATMEL_TC_REG(tcbpwmc->channel, RA),
> +				    &tcbpwm->duty);
>  		else
> -			tcbpwm->duty =
> -				__raw_readl(regs + ATMEL_TC_REG(group, RB));
> +			regmap_read(tcbpwmc->regmap,
> +				    ATMEL_TC_REG(tcbpwmc->channel, RB),
> +				    &tcbpwm->duty);
>  
>  		tcbpwm->div = cmr & ATMEL_TC_TCCLKS;
> -		tcbpwm->period = __raw_readl(regs + ATMEL_TC_REG(group, RC));
> +		regmap_read(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, RC),
> +			    &tcbpwm->period);
>  		cmr &= (ATMEL_TC_TCCLKS | ATMEL_TC_ACMR_MASK |
>  			ATMEL_TC_BCMR_MASK);
>  	} else
>  		cmr = 0;
>  
>  	cmr |= ATMEL_TC_WAVE | ATMEL_TC_WAVESEL_UP_AUTO | ATMEL_TC_EEVT_XC0;
> -	__raw_writel(cmr, regs + ATMEL_TC_REG(group, CMR));
> +	regmap_write(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CMR), cmr);
>  	spin_unlock(&tcbpwmc->lock);
>  
>  	tcbpwmc->pwms[pwm->hwpwm] = tcbpwm;
> @@ -131,9 +139,8 @@ static void atmel_tcb_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
>  {
>  	struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip);
>  	struct atmel_tcb_pwm_device *tcbpwm = pwm_get_chip_data(pwm);
> -	struct atmel_tc *tc = tcbpwmc->tc;
>  
> -	clk_disable_unprepare(tc->clk[pwm->hwpwm / 2]);
> +	clk_disable_unprepare(tcbpwmc->clk);
>  	tcbpwmc->pwms[pwm->hwpwm] = NULL;
>  	devm_kfree(chip->dev, tcbpwm);
>  }
> @@ -142,10 +149,6 @@ static void atmel_tcb_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
>  {
>  	struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip);
>  	struct atmel_tcb_pwm_device *tcbpwm = pwm_get_chip_data(pwm);
> -	struct atmel_tc *tc = tcbpwmc->tc;
> -	void __iomem *regs = tc->regs;
> -	unsigned group = pwm->hwpwm / 2;
> -	unsigned index = pwm->hwpwm % 2;
>  	unsigned cmr;
>  	enum pwm_polarity polarity = tcbpwm->polarity;
>  
> @@ -161,10 +164,10 @@ static void atmel_tcb_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
>  		polarity = !polarity;
>  
>  	spin_lock(&tcbpwmc->lock);
> -	cmr = __raw_readl(regs + ATMEL_TC_REG(group, CMR));
> +	regmap_read(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CMR), &cmr);
>  
>  	/* flush old setting and set the new one */
> -	if (index == 0) {
> +	if (pwm->hwpwm == 0) {
>  		cmr &= ~ATMEL_TC_ACMR_MASK;
>  		if (polarity == PWM_POLARITY_INVERSED)
>  			cmr |= ATMEL_TC_ASWTRG_CLEAR;
> @@ -178,20 +181,22 @@ static void atmel_tcb_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
>  			cmr |= ATMEL_TC_BSWTRG_SET;
>  	}
>  
> -	__raw_writel(cmr, regs + ATMEL_TC_REG(group, CMR));
> +	regmap_write(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CMR), cmr);
>  
>  	/*
>  	 * Use software trigger to apply the new setting.
>  	 * If both PWM devices in this group are disabled we stop the clock.
>  	 */
>  	if (!(cmr & (ATMEL_TC_ACPC | ATMEL_TC_BCPC))) {
> -		__raw_writel(ATMEL_TC_SWTRG | ATMEL_TC_CLKDIS,
> -			     regs + ATMEL_TC_REG(group, CCR));
> -		tcbpwmc->bkup[group].enabled = 1;
> +		regmap_write(tcbpwmc->regmap,
> +			     ATMEL_TC_REG(tcbpwmc->channel, CCR),
> +			     ATMEL_TC_SWTRG | ATMEL_TC_CLKDIS);
> +		tcbpwmc->bkup.enabled = 1;
>  	} else {
> -		__raw_writel(ATMEL_TC_SWTRG, regs +
> -			     ATMEL_TC_REG(group, CCR));
> -		tcbpwmc->bkup[group].enabled = 0;
> +		regmap_write(tcbpwmc->regmap,
> +			     ATMEL_TC_REG(tcbpwmc->channel, CCR),
> +			     ATMEL_TC_SWTRG);
> +		tcbpwmc->bkup.enabled = 0;
>  	}
>  
>  	spin_unlock(&tcbpwmc->lock);
> @@ -201,10 +206,6 @@ static int atmel_tcb_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
>  {
>  	struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip);
>  	struct atmel_tcb_pwm_device *tcbpwm = pwm_get_chip_data(pwm);
> -	struct atmel_tc *tc = tcbpwmc->tc;
> -	void __iomem *regs = tc->regs;
> -	unsigned group = pwm->hwpwm / 2;
> -	unsigned index = pwm->hwpwm % 2;
>  	u32 cmr;
>  	enum pwm_polarity polarity = tcbpwm->polarity;
>  
> @@ -220,12 +221,12 @@ static int atmel_tcb_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
>  		polarity = !polarity;
>  
>  	spin_lock(&tcbpwmc->lock);
> -	cmr = __raw_readl(regs + ATMEL_TC_REG(group, CMR));
> +	regmap_read(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CMR), &cmr);
>  
>  	/* flush old setting and set the new one */
>  	cmr &= ~ATMEL_TC_TCCLKS;
>  
> -	if (index == 0) {
> +	if (pwm->hwpwm == 0) {
>  		cmr &= ~ATMEL_TC_ACMR_MASK;
>  
>  		/* Set CMR flags according to given polarity */
> @@ -248,7 +249,7 @@ static int atmel_tcb_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
>  	 * this config till next config call.
>  	 */
>  	if (tcbpwm->duty != tcbpwm->period && tcbpwm->duty > 0) {
> -		if (index == 0) {
> +		if (pwm->hwpwm == 0) {
>  			if (polarity == PWM_POLARITY_INVERSED)
>  				cmr |= ATMEL_TC_ACPA_SET | ATMEL_TC_ACPC_CLEAR;
>  			else
> @@ -263,19 +264,24 @@ static int atmel_tcb_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
>  
>  	cmr |= (tcbpwm->div & ATMEL_TC_TCCLKS);
>  
> -	__raw_writel(cmr, regs + ATMEL_TC_REG(group, CMR));
> +	regmap_write(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CMR), cmr);
>  
> -	if (index == 0)
> -		__raw_writel(tcbpwm->duty, regs + ATMEL_TC_REG(group, RA));
> +	if (pwm->hwpwm == 0)
> +		regmap_write(tcbpwmc->regmap,
> +			     ATMEL_TC_REG(tcbpwmc->channel, RA),
> +			     tcbpwm->duty);
>  	else
> -		__raw_writel(tcbpwm->duty, regs + ATMEL_TC_REG(group, RB));
> +		regmap_write(tcbpwmc->regmap,
> +			     ATMEL_TC_REG(tcbpwmc->channel, RB),
> +			     tcbpwm->duty);
>  
> -	__raw_writel(tcbpwm->period, regs + ATMEL_TC_REG(group, RC));
> +	regmap_write(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, RC),
> +		     tcbpwm->period);
>  
>  	/* Use software trigger to apply the new setting */
> -	__raw_writel(ATMEL_TC_CLKEN | ATMEL_TC_SWTRG,
> -		     regs + ATMEL_TC_REG(group, CCR));
> -	tcbpwmc->bkup[group].enabled = 1;
> +	regmap_write(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CCR),
> +		     ATMEL_TC_SWTRG | ATMEL_TC_CLKEN);
> +	tcbpwmc->bkup.enabled = 1;
>  	spin_unlock(&tcbpwmc->lock);
>  	return 0;
>  }
> @@ -285,15 +291,12 @@ static int atmel_tcb_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
>  {
>  	struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip);
>  	struct atmel_tcb_pwm_device *tcbpwm = pwm_get_chip_data(pwm);
> -	unsigned group = pwm->hwpwm / 2;
> -	unsigned index = pwm->hwpwm % 2;
>  	struct atmel_tcb_pwm_device *atcbpwm = NULL;
> -	struct atmel_tc *tc = tcbpwmc->tc;
>  	int i;
>  	int slowclk = 0;
>  	unsigned period;
>  	unsigned duty;
> -	unsigned rate = clk_get_rate(tc->clk[group]);
> +	unsigned rate = clk_get_rate(tcbpwmc->clk);
>  	unsigned long long min;
>  	unsigned long long max;
>  
> @@ -301,13 +304,13 @@ static int atmel_tcb_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
>  	 * Find best clk divisor:
>  	 * the smallest divisor which can fulfill the period_ns requirements.
>  	 */
> -	for (i = 0; i < 5; ++i) {
> -		if (atmel_tc_divisors[i] == 0) {
> +	for (i = 0; i < ARRAY_SIZE(atmel_tcb_divisors); ++i) {
> +		if (atmel_tcb_divisors[i] == 0) {
>  			slowclk = i;
>  			continue;
>  		}
> -		min = div_u64((u64)NSEC_PER_SEC * atmel_tc_divisors[i], rate);
> -		max = min << tc->tcb_config->counter_width;
> +		min = div_u64((u64)NSEC_PER_SEC * atmel_tcb_divisors[i], rate);
> +		max = min << tcbpwmc->width;
>  		if (max >= period_ns)
>  			break;
>  	}
> @@ -316,11 +319,11 @@ static int atmel_tcb_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
>  	 * If none of the divisor are small enough to represent period_ns
>  	 * take slow clock (32KHz).
>  	 */
> -	if (i == 5) {
> +	if (i == ARRAY_SIZE(atmel_tcb_divisors)) {
>  		i = slowclk;
> -		rate = clk_get_rate(tc->slow_clk);
> +		rate = clk_get_rate(tcbpwmc->slow_clk);
>  		min = div_u64(NSEC_PER_SEC, rate);
> -		max = min << tc->tcb_config->counter_width;
> +		max = min << tcbpwmc->width;
>  
>  		/* If period is too big return ERANGE error */
>  		if (max < period_ns)
> @@ -330,17 +333,13 @@ static int atmel_tcb_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
>  	duty = div_u64(duty_ns, min);
>  	period = div_u64(period_ns, min);
>  
> -	if (index == 0)
> -		atcbpwm = tcbpwmc->pwms[pwm->hwpwm + 1];
> +	if (pwm->hwpwm == 0)
> +		atcbpwm = tcbpwmc->pwms[1];
>  	else
> -		atcbpwm = tcbpwmc->pwms[pwm->hwpwm - 1];
> +		atcbpwm = tcbpwmc->pwms[0];
>  
>  	/*
> -	 * PWM devices provided by TCB driver are grouped by 2:
> -	 * - group 0: PWM 0 & 1
> -	 * - group 1: PWM 2 & 3
> -	 * - group 2: PWM 4 & 5
> -	 *
> +	 * PWM devices provided by the TCB driver are grouped by 2.
>  	 * PWM devices in a given group must be configured with the
>  	 * same period_ns.
>  	 *
> @@ -376,32 +375,63 @@ static const struct pwm_ops atmel_tcb_pwm_ops = {
>  	.owner = THIS_MODULE,
>  };
>  
> +static struct atmel_tcb_config tcb_rm9200_config = {
> +	.counter_width = 16,
> +};
> +
> +static struct atmel_tcb_config tcb_sam9x5_config = {
> +	.counter_width = 32,
> +};
> +
> +static const struct of_device_id atmel_tcb_of_match[] = {
> +	{ .compatible = "atmel,at91rm9200-tcb", .data = &tcb_rm9200_config, },
> +	{ .compatible = "atmel,at91sam9x5-tcb", .data = &tcb_sam9x5_config, },
> +	{ /* sentinel */ }
> +};
> +
>  static int atmel_tcb_pwm_probe(struct platform_device *pdev)
>  {
> +	const struct of_device_id *match;
>  	struct atmel_tcb_pwm_chip *tcbpwm;
> +	const struct atmel_tcb_config *config;
>  	struct device_node *np = pdev->dev.of_node;
> -	struct atmel_tc *tc;
> +	struct regmap *regmap;
> +	struct clk *clk;
> +	struct clk *slow_clk;
> +	char clk_name[] = "t0_clk";
>  	int err;
> -	int tcblock;
> +	int channel;
>  
> -	err = of_property_read_u32(np, "tc-block", &tcblock);
> +	err = of_property_read_u32(np, "reg", &channel);
>  	if (err < 0) {
>  		dev_err(&pdev->dev,
> -			"failed to get Timer Counter Block number from device tree (error: %d)\n",
> +			"failed to get Timer Counter Block channel from device tree (error: %d)\n",
>  			err);
>  		return err;
>  	}
>  
> -	tc = atmel_tc_alloc(tcblock);
> -	if (tc == NULL) {
> -		dev_err(&pdev->dev, "failed to allocate Timer Counter Block\n");
> -		return -ENOMEM;
> -	}
> +	regmap = syscon_node_to_regmap(np->parent);
> +	if (IS_ERR(regmap))
> +		return PTR_ERR(regmap);
> +
> +	slow_clk = of_clk_get_by_name(np->parent, "slow_clk");
> +	if (IS_ERR(slow_clk))
> +		return PTR_ERR(slow_clk);
> +
> +	clk_name[1] += channel;
> +	clk = of_clk_get_by_name(np->parent, clk_name);
> +	if (IS_ERR(clk))
> +		clk = of_clk_get_by_name(np->parent, "t0_clk");
> +	if (IS_ERR(clk))
> +		return PTR_ERR(clk);
> +
> +	match = of_match_node(atmel_tcb_of_match, np->parent);
> +	config = match->data;
>  
>  	tcbpwm = devm_kzalloc(&pdev->dev, sizeof(*tcbpwm), GFP_KERNEL);
>  	if (tcbpwm == NULL) {
>  		err = -ENOMEM;
> -		goto err_free_tc;
> +		goto err_slow_clk;
>  	}
>  
>  	tcbpwm->chip.dev = &pdev->dev;
> @@ -410,11 +440,15 @@ static int atmel_tcb_pwm_probe(struct platform_device *pdev)
>  	tcbpwm->chip.of_pwm_n_cells = 3;
>  	tcbpwm->chip.base = -1;
>  	tcbpwm->chip.npwm = NPWM;
> -	tcbpwm->tc = tc;
> +	tcbpwm->channel = channel;
> +	tcbpwm->regmap = regmap;
> +	tcbpwm->clk = clk;
> +	tcbpwm->slow_clk = slow_clk;
> +	tcbpwm->width = config->counter_width;
>  
> -	err = clk_prepare_enable(tc->slow_clk);
> +	err = clk_prepare_enable(slow_clk);
>  	if (err)
> -		goto err_free_tc;
> +		goto err_slow_clk;
>  
>  	spin_lock_init(&tcbpwm->lock);
>  
> @@ -427,10 +461,10 @@ static int atmel_tcb_pwm_probe(struct platform_device *pdev)
>  	return 0;
>  
>  err_disable_clk:
> -	clk_disable_unprepare(tcbpwm->tc->slow_clk);
> +	clk_disable_unprepare(tcbpwm->slow_clk);
>  
> -err_free_tc:
> -	atmel_tc_free(tc);
> +err_slow_clk:
> +	clk_put(slow_clk);
>  
>  	return err;
>  }
> @@ -440,14 +474,14 @@ static int atmel_tcb_pwm_remove(struct platform_device *pdev)
>  	struct atmel_tcb_pwm_chip *tcbpwm = platform_get_drvdata(pdev);
>  	int err;
>  
> -	clk_disable_unprepare(tcbpwm->tc->slow_clk);
> +	clk_disable_unprepare(tcbpwm->slow_clk);
> +	clk_put(tcbpwm->slow_clk);
> +	clk_put(tcbpwm->clk);
>  
>  	err = pwmchip_remove(&tcbpwm->chip);
>  	if (err < 0)
>  		return err;
>  
> -	atmel_tc_free(tcbpwm->tc);
> -
>  	return 0;
>  }
>  
> @@ -461,38 +495,33 @@ MODULE_DEVICE_TABLE(of, atmel_tcb_pwm_dt_ids);
>  static int atmel_tcb_pwm_suspend(struct device *dev)
>  {
>  	struct atmel_tcb_pwm_chip *tcbpwm = dev_get_drvdata(dev);
> -	void __iomem *base = tcbpwm->tc->regs;
> -	int i;
> +	struct atmel_tcb_channel *chan = &tcbpwm->bkup;
> +	unsigned int channel = tcbpwm->channel;
>  
> -	for (i = 0; i < (NPWM / 2); i++) {
> -		struct atmel_tcb_channel *chan = &tcbpwm->bkup[i];
> +	regmap_read(tcbpwm->regmap, ATMEL_TC_REG(channel, CMR), &chan->cmr);
> +	regmap_read(tcbpwm->regmap, ATMEL_TC_REG(channel, RA), &chan->ra);
> +	regmap_read(tcbpwm->regmap, ATMEL_TC_REG(channel, RB), &chan->rb);
> +	regmap_read(tcbpwm->regmap, ATMEL_TC_REG(channel, RC), &chan->rc);
>  
> -		chan->cmr = readl(base + ATMEL_TC_REG(i, CMR));
> -		chan->ra = readl(base + ATMEL_TC_REG(i, RA));
> -		chan->rb = readl(base + ATMEL_TC_REG(i, RB));
> -		chan->rc = readl(base + ATMEL_TC_REG(i, RC));
> -	}
>  	return 0;
>  }
>  
>  static int atmel_tcb_pwm_resume(struct device *dev)
>  {
>  	struct atmel_tcb_pwm_chip *tcbpwm = dev_get_drvdata(dev);
> -	void __iomem *base = tcbpwm->tc->regs;
> -	int i;
> +	struct atmel_tcb_channel *chan = &tcbpwm->bkup;
> +	unsigned int channel = tcbpwm->channel;
>  
> -	for (i = 0; i < (NPWM / 2); i++) {
> -		struct atmel_tcb_channel *chan = &tcbpwm->bkup[i];
> +	regmap_write(tcbpwm->regmap, ATMEL_TC_REG(channel, CMR), chan->cmr);
> +	regmap_write(tcbpwm->regmap, ATMEL_TC_REG(channel, RA), chan->ra);
> +	regmap_write(tcbpwm->regmap, ATMEL_TC_REG(channel, RB), chan->rb);
> +	regmap_write(tcbpwm->regmap, ATMEL_TC_REG(channel, RC), chan->rc);
> +
> +	if (chan->enabled)
> +		regmap_write(tcbpwm->regmap,
> +			     ATMEL_TC_CLKEN | ATMEL_TC_SWTRG,
> +			     ATMEL_TC_REG(channel, CCR));
>  
> -		writel(chan->cmr, base + ATMEL_TC_REG(i, CMR));
> -		writel(chan->ra, base + ATMEL_TC_REG(i, RA));
> -		writel(chan->rb, base + ATMEL_TC_REG(i, RB));
> -		writel(chan->rc, base + ATMEL_TC_REG(i, RC));
> -		if (chan->enabled) {
> -			writel(ATMEL_TC_CLKEN | ATMEL_TC_SWTRG,
> -				base + ATMEL_TC_REG(i, CCR));
> -		}
> -	}
>  	return 0;
>  }
>  #endif
> -- 
> 2.25.0
> 

-- 
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com