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SubjectRe: [PATCH] gpio-mvebu: no hardcoded timer assignment for pwm
From
Thanks for raising this patch. I have been adjusting it forever, would 
be great to get it in.
Looks good from my side too.


Am 30.01.2024 um 11:55 schrieb Finn Behrens:
> Removes the hardcoded timer assignment of timers to pwm controllers.
> This allows to use more than one pwm per gpio bank.
>
> Original patch with chip_data interface by Heisath <jannis@imserv.org>
>
> Link: https://wiki.kobol.io/helios4/pwm/#patch-requirement
> Co-developed-by: Yureka Lilian <yuka@yuka.dev>
> Signed-off-by: Yureka Lilian <yuka@yuka.dev>
> Signed-off-by: Finn Behrens <me@kloenk.de>
> ---
> drivers/gpio/gpio-mvebu.c | 223 ++++++++++++++++++++++++--------------
> 1 file changed, 139 insertions(+), 84 deletions(-)
>
> diff --git a/drivers/gpio/gpio-mvebu.c b/drivers/gpio/gpio-mvebu.c
> index a13f3c18ccd4..303ea3be0b69 100644
> --- a/drivers/gpio/gpio-mvebu.c
> +++ b/drivers/gpio/gpio-mvebu.c
> @@ -94,21 +94,43 @@
>
> #define MVEBU_MAX_GPIO_PER_BANK 32
>
> -struct mvebu_pwm {
> +enum mvebu_pwm_ctrl {
> + MVEBU_PWM_CTRL_SET_A = 0,
> + MVEBU_PWM_CTRL_SET_B,
> + MVEBU_PWM_CTRL_MAX
> +};
> +
> +struct mvebu_pwmchip {
> struct regmap *regs;
> u32 offset;
> unsigned long clk_rate;
> - struct gpio_desc *gpiod;
> - struct pwm_chip chip;
> spinlock_t lock;
> - struct mvebu_gpio_chip *mvchip;
> + bool in_use;
>
> /* Used to preserve GPIO/PWM registers across suspend/resume */
> - u32 blink_select;
> u32 blink_on_duration;
> u32 blink_off_duration;
> };
>
> +struct mvebu_pwm_chip_drv {
> + enum mvebu_pwm_ctrl ctrl;
> + struct gpio_desc *gpiod;
> + bool master;
> +};
> +
> +struct mvebu_pwm {
> + struct pwm_chip chip;
> + struct mvebu_gpio_chip *mvchip;
> + struct mvebu_pwmchip controller;
> + enum mvebu_pwm_ctrl default_controller;
> +
> + /* Used to preserve GPIO/PWM registers across suspend/resume */
> + u32 blink_select;
> + struct mvebu_pwm_chip_drv drv[];
> +};
> +
> +static struct mvebu_pwmchip *mvebu_pwm_list[MVEBU_PWM_CTRL_MAX];
> +
> struct mvebu_gpio_chip {
> struct gpio_chip chip;
> struct regmap *regs;
> @@ -285,12 +307,12 @@ mvebu_gpio_write_level_mask(struct mvebu_gpio_chip *mvchip, u32 val)
> * Functions returning offsets of individual registers for a given
> * PWM controller.
> */
> -static unsigned int mvebu_pwmreg_blink_on_duration(struct mvebu_pwm *mvpwm)
> +static unsigned int mvebu_pwmreg_blink_on_duration(struct mvebu_pwmchip *mvpwm)
> {
> return mvpwm->offset + PWM_BLINK_ON_DURATION_OFF;
> }
>
> -static unsigned int mvebu_pwmreg_blink_off_duration(struct mvebu_pwm *mvpwm)
> +static unsigned int mvebu_pwmreg_blink_off_duration(struct mvebu_pwmchip *mvpwm)
> {
> return mvpwm->offset + PWM_BLINK_OFF_DURATION_OFF;
> }
> @@ -623,39 +645,71 @@ static int mvebu_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
> struct mvebu_pwm *mvpwm = to_mvebu_pwm(chip);
> struct mvebu_gpio_chip *mvchip = mvpwm->mvchip;
> struct gpio_desc *desc;
> + enum mvebu_pwm_ctrl id;
> unsigned long flags;
> int ret = 0;
> + struct mvebu_pwm_chip_drv *drv = &mvpwm->drv[pwm->hwpwm];
>
> - spin_lock_irqsave(&mvpwm->lock, flags);
> + spin_lock_irqsave(&mvpwm->controller.lock, flags);
>
> - if (mvpwm->gpiod) {
> + if (drv->gpiod || (mvchip->blink_en_reg & BIT(pwm->hwpwm))) {
> ret = -EBUSY;
> - } else {
> - desc = gpiochip_request_own_desc(&mvchip->chip,
> - pwm->hwpwm, "mvebu-pwm",
> - GPIO_ACTIVE_HIGH,
> - GPIOD_OUT_LOW);
> - if (IS_ERR(desc)) {
> - ret = PTR_ERR(desc);
> - goto out;
> - }
> + goto out;
> + }
> +
> + desc = gpiochip_request_own_desc(&mvchip->chip,
> + pwm->hwpwm, "mvebu-pwm",
> + GPIO_ACTIVE_HIGH,
> + GPIOD_OUT_LOW);
> + if (IS_ERR(desc)) {
> + ret = PTR_ERR(desc);
> + goto out;
> + }
>
> - mvpwm->gpiod = desc;
> + ret = gpiod_direction_output(desc, 0);
> + if (ret) {
> + gpiochip_free_own_desc(desc);
> + goto out;
> }
> +
> + for (id = MVEBU_PWM_CTRL_SET_A; id < MVEBU_PWM_CTRL_MAX; id++) {
> + if (!mvebu_pwm_list[id]->in_use) {
> + drv->ctrl = id;
> + drv->master = true;
> + mvebu_pwm_list[id]->in_use = true;
> + break;
> + }
> + }
> +
> + if (!drv->master)
> + drv->ctrl = mvpwm->default_controller;
> +
> + regmap_update_bits(mvchip->regs, GPIO_BLINK_CNT_SELECT_OFF + mvchip->offset,
> + BIT(pwm->hwpwm), drv->ctrl ? BIT(pwm->hwpwm) : 0);
> +
> + drv->gpiod = desc;
> +
> + regmap_read(mvchip->regs, GPIO_BLINK_CNT_SELECT_OFF + mvchip->offset,
> + &mvpwm->blink_select);
> out:
> - spin_unlock_irqrestore(&mvpwm->lock, flags);
> + spin_unlock_irqrestore(&mvpwm->controller.lock, flags);
> return ret;
> }
>
> static void mvebu_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
> {
> struct mvebu_pwm *mvpwm = to_mvebu_pwm(chip);
> + struct mvebu_pwm_chip_drv *drv = &mvpwm->drv[pwm->hwpwm];
> unsigned long flags;
>
> - spin_lock_irqsave(&mvpwm->lock, flags);
> - gpiochip_free_own_desc(mvpwm->gpiod);
> - mvpwm->gpiod = NULL;
> - spin_unlock_irqrestore(&mvpwm->lock, flags);
> + spin_lock_irqsave(&mvpwm->controller.lock, flags);
> + if (drv->master)
> + mvebu_pwm_list[drv->ctrl]->in_use = false;
> +
> + gpiochip_free_own_desc(drv->gpiod);
> + memset(drv, 0, sizeof(struct mvebu_pwm_chip_drv));
> +
> + spin_unlock_irqrestore(&mvpwm->controller.lock, flags);
> }
>
> static int mvebu_pwm_get_state(struct pwm_chip *chip,
> @@ -665,28 +719,35 @@ static int mvebu_pwm_get_state(struct pwm_chip *chip,
>
> struct mvebu_pwm *mvpwm = to_mvebu_pwm(chip);
> struct mvebu_gpio_chip *mvchip = mvpwm->mvchip;
> + struct mvebu_pwm_chip_drv *drv = &mvpwm->drv[pwm->hwpwm];
> + struct mvebu_pwmchip *controller;
> unsigned long long val;
> unsigned long flags;
> u32 u;
>
> - spin_lock_irqsave(&mvpwm->lock, flags);
> + if (drv->gpiod)
> + controller = mvebu_pwm_list[drv->ctrl];
> + else
> + controller = &mvpwm->controller;
> +
> + spin_lock_irqsave(&controller->lock, flags);
>
> - regmap_read(mvpwm->regs, mvebu_pwmreg_blink_on_duration(mvpwm), &u);
> + regmap_read(controller->regs, mvebu_pwmreg_blink_on_duration(controller), &u);
> /* Hardware treats zero as 2^32. See mvebu_pwm_apply(). */
> if (u > 0)
> val = u;
> else
> val = UINT_MAX + 1ULL;
> state->duty_cycle = DIV_ROUND_UP_ULL(val * NSEC_PER_SEC,
> - mvpwm->clk_rate);
> + controller->clk_rate);
>
> - regmap_read(mvpwm->regs, mvebu_pwmreg_blink_off_duration(mvpwm), &u);
> + regmap_read(controller->regs, mvebu_pwmreg_blink_off_duration(controller), &u);
> /* period = on + off duration */
> if (u > 0)
> val += u;
> else
> val += UINT_MAX + 1ULL;
> - state->period = DIV_ROUND_UP_ULL(val * NSEC_PER_SEC, mvpwm->clk_rate);
> + state->period = DIV_ROUND_UP_ULL(val * NSEC_PER_SEC, controller->clk_rate);
>
> regmap_read(mvchip->regs, GPIO_BLINK_EN_OFF + mvchip->offset, &u);
> if (u)
> @@ -694,7 +755,7 @@ static int mvebu_pwm_get_state(struct pwm_chip *chip,
> else
> state->enabled = false;
>
> - spin_unlock_irqrestore(&mvpwm->lock, flags);
> + spin_unlock_irqrestore(&controller->lock, flags);
>
> return 0;
> }
> @@ -703,6 +764,8 @@ static int mvebu_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
> const struct pwm_state *state)
> {
> struct mvebu_pwm *mvpwm = to_mvebu_pwm(chip);
> + struct mvebu_pwm_chip_drv *drv = &mvpwm->drv[pwm->hwpwm];
> + struct mvebu_pwmchip *controller;
> struct mvebu_gpio_chip *mvchip = mvpwm->mvchip;
> unsigned long long val;
> unsigned long flags;
> @@ -711,7 +774,11 @@ static int mvebu_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
> if (state->polarity != PWM_POLARITY_NORMAL)
> return -EINVAL;
>
> - val = (unsigned long long) mvpwm->clk_rate * state->duty_cycle;
> + if (drv->gpiod)
> + controller = mvebu_pwm_list[drv->ctrl];
> + else
> + controller = &mvpwm->controller;
> + val = (unsigned long long) controller->clk_rate * state->duty_cycle;
> do_div(val, NSEC_PER_SEC);
> if (val > UINT_MAX + 1ULL)
> return -EINVAL;
> @@ -726,7 +793,7 @@ static int mvebu_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
> else
> on = 1;
>
> - val = (unsigned long long) mvpwm->clk_rate * state->period;
> + val = (unsigned long long) controller->clk_rate * state->period;
> do_div(val, NSEC_PER_SEC);
> val -= on;
> if (val > UINT_MAX + 1ULL)
> @@ -738,16 +805,16 @@ static int mvebu_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
> else
> off = 1;
>
> - spin_lock_irqsave(&mvpwm->lock, flags);
> + spin_lock_irqsave(&controller->lock, flags);
>
> - regmap_write(mvpwm->regs, mvebu_pwmreg_blink_on_duration(mvpwm), on);
> - regmap_write(mvpwm->regs, mvebu_pwmreg_blink_off_duration(mvpwm), off);
> + regmap_write(controller->regs, mvebu_pwmreg_blink_on_duration(controller), on);
> + regmap_write(controller->regs, mvebu_pwmreg_blink_off_duration(controller), off);
> if (state->enabled)
> mvebu_gpio_blink(&mvchip->chip, pwm->hwpwm, 1);
> else
> mvebu_gpio_blink(&mvchip->chip, pwm->hwpwm, 0);
>
> - spin_unlock_irqrestore(&mvpwm->lock, flags);
> + spin_unlock_irqrestore(&controller->lock, flags);
>
> return 0;
> }
> @@ -762,25 +829,27 @@ static const struct pwm_ops mvebu_pwm_ops = {
> static void __maybe_unused mvebu_pwm_suspend(struct mvebu_gpio_chip *mvchip)
> {
> struct mvebu_pwm *mvpwm = mvchip->mvpwm;
> + struct mvebu_pwmchip *controller = &mvpwm->controller;
>
> regmap_read(mvchip->regs, GPIO_BLINK_CNT_SELECT_OFF + mvchip->offset,
> &mvpwm->blink_select);
> - regmap_read(mvpwm->regs, mvebu_pwmreg_blink_on_duration(mvpwm),
> - &mvpwm->blink_on_duration);
> - regmap_read(mvpwm->regs, mvebu_pwmreg_blink_off_duration(mvpwm),
> - &mvpwm->blink_off_duration);
> + regmap_read(controller->regs, mvebu_pwmreg_blink_on_duration(controller),
> + &controller->blink_on_duration);
> + regmap_read(controller->regs, mvebu_pwmreg_blink_off_duration(controller),
> + &controller->blink_off_duration);
> }
>
> static void __maybe_unused mvebu_pwm_resume(struct mvebu_gpio_chip *mvchip)
> {
> struct mvebu_pwm *mvpwm = mvchip->mvpwm;
> + struct mvebu_pwmchip *controller = &mvpwm->controller;
>
> regmap_write(mvchip->regs, GPIO_BLINK_CNT_SELECT_OFF + mvchip->offset,
> mvpwm->blink_select);
> - regmap_write(mvpwm->regs, mvebu_pwmreg_blink_on_duration(mvpwm),
> - mvpwm->blink_on_duration);
> - regmap_write(mvpwm->regs, mvebu_pwmreg_blink_off_duration(mvpwm),
> - mvpwm->blink_off_duration);
> + regmap_write(controller->regs, mvebu_pwmreg_blink_on_duration(controller),
> + controller->blink_on_duration);
> + regmap_write(controller->regs, mvebu_pwmreg_blink_off_duration(controller),
> + controller->blink_off_duration);
> }
>
> static int mvebu_pwm_probe(struct platform_device *pdev,
> @@ -792,6 +861,7 @@ static int mvebu_pwm_probe(struct platform_device *pdev,
> void __iomem *base;
> u32 offset;
> u32 set;
> + enum mvebu_pwm_ctrl ctrl_set;
>
> if (mvchip->soc_variant == MVEBU_GPIO_SOC_VARIANT_A8K) {
> int ret = of_property_read_u32(dev->of_node,
> @@ -813,57 +883,39 @@ static int mvebu_pwm_probe(struct platform_device *pdev,
> if (IS_ERR(mvchip->clk))
> return PTR_ERR(mvchip->clk);
>
> - mvpwm = devm_kzalloc(dev, sizeof(struct mvebu_pwm), GFP_KERNEL);
> + mvpwm = devm_kzalloc(dev, struct_size(mvpwm, drv, mvchip->chip.ngpio), GFP_KERNEL);
> if (!mvpwm)
> return -ENOMEM;
> mvchip->mvpwm = mvpwm;
> mvpwm->mvchip = mvchip;
> - mvpwm->offset = offset;
>
> - if (mvchip->soc_variant == MVEBU_GPIO_SOC_VARIANT_A8K) {
> - mvpwm->regs = mvchip->regs;
> + base = devm_platform_ioremap_resource_byname(pdev, "pwm");
> + if (IS_ERR(base))
> + return PTR_ERR(base);
> + mvpwm->controller.regs = devm_regmap_init_mmio(&pdev->dev, base,
> + &mvebu_gpio_regmap_config);
> + if (IS_ERR(mvpwm->controller.regs))
> + return PTR_ERR(mvpwm->controller.regs);
>
> - switch (mvchip->offset) {
> - case AP80X_GPIO0_OFF_A8K:
> - case CP11X_GPIO0_OFF_A8K:
> - /* Blink counter A */
> - set = 0;
> - break;
> - case CP11X_GPIO1_OFF_A8K:
> - /* Blink counter B */
> - set = U32_MAX;
> - mvpwm->offset += PWM_BLINK_COUNTER_B_OFF;
> - break;
> - default:
> - return -EINVAL;
> - }
> + /*
> + * User set A for lines of GPIO chip with id 0, B for GPIO chip
> + * with id 1. Don't allow further GPIO chips to be used for PWM.
> + */
> + if (id == 0) {
> + set = 0;
> + ctrl_set = MVEBU_PWM_CTRL_SET_A;
> + } else if (id == 1) {
> + set = U32_MAX;
> + ctrl_set = MVEBU_PWM_CTRL_SET_B;
> } else {
> - base = devm_platform_ioremap_resource_byname(pdev, "pwm");
> - if (IS_ERR(base))
> - return PTR_ERR(base);
> -
> - mvpwm->regs = devm_regmap_init_mmio(&pdev->dev, base,
> - &mvebu_gpio_regmap_config);
> - if (IS_ERR(mvpwm->regs))
> - return PTR_ERR(mvpwm->regs);
> -
> - /*
> - * Use set A for lines of GPIO chip with id 0, B for GPIO chip
> - * with id 1. Don't allow further GPIO chips to be used for PWM.
> - */
> - if (id == 0)
> - set = 0;
> - else if (id == 1)
> - set = U32_MAX;
> - else
> - return -EINVAL;
> + return -EINVAL;
> }
>
> regmap_write(mvchip->regs,
> GPIO_BLINK_CNT_SELECT_OFF + mvchip->offset, set);
>
> - mvpwm->clk_rate = clk_get_rate(mvchip->clk);
> - if (!mvpwm->clk_rate) {
> + mvpwm->controller.clk_rate = clk_get_rate(mvchip->clk);
> + if (!mvpwm->controller.clk_rate) {
> dev_err(dev, "failed to get clock rate\n");
> return -EINVAL;
> }
> @@ -872,7 +924,10 @@ static int mvebu_pwm_probe(struct platform_device *pdev,
> mvpwm->chip.ops = &mvebu_pwm_ops;
> mvpwm->chip.npwm = mvchip->chip.ngpio;
>
> - spin_lock_init(&mvpwm->lock);
> + spin_lock_init(&mvpwm->controller.lock);
> +
> + mvpwm->default_controller = ctrl_set;
> + mvebu_pwm_list[ctrl_set] = &mvpwm->controller;
>
> return devm_pwmchip_add(dev, &mvpwm->chip);
> }


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