Re: [PATCH v3 07/15] pinctrl: renesas: pinctrl-rzg2l: Add function pointer for locking/unlocking the PFC register

[claudiu beznea <claudiu.beznea@tuxon.dev>]

On 30.05.2024 20:38, Prabhakar wrote:
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> 
> On the RZ/G2L SoC, the PFCWE bit controls writing to PFC registers.
> However, on the RZ/V2H(P) SoC, the PFCWE (REGWE_A on RZ/V2H) bit controls
> writing to both PFC and PMC registers. Additionally, BIT(7) B0WI is
> undocumented for the PWPR register on RZ/V2H(P) SoC. To accommodate these
> differences across SoC variants, introduce the pwpr_pfc_lock_unlock()
> function pointer.
> 
> Note, in rzg2l_pinctrl_set_pfc_mode() the pwpr_pfc_lock_unlock(.., false)
> is now called before PMC read/write and pwpr_pfc_lock_unlock(.., true) is
> now called after PMC read/write this is to keep changes minimal for
> RZ/V2H(P) SoC.
> 
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

Tested-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> # on RZ/G3S

> ---
> v2->v3
> - Introduced single function pointer to (un)lock
> - Updated commit message
> 
> RFC->v2
> - Introduced function pointer for (un)lock
> ---
>  drivers/pinctrl/renesas/pinctrl-rzg2l.c | 44 +++++++++++++++----------
>  1 file changed, 27 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/pinctrl/renesas/pinctrl-rzg2l.c b/drivers/pinctrl/renesas/pinctrl-rzg2l.c
> index 6e3b1adb95f6..a3fd14b95c5a 100644
> --- a/drivers/pinctrl/renesas/pinctrl-rzg2l.c
> +++ b/drivers/pinctrl/renesas/pinctrl-rzg2l.c
> @@ -241,6 +241,8 @@ struct rzg2l_dedicated_configs {
>  	u64 config;
>  };
>  
> +struct rzg2l_pinctrl;
> +
>  struct rzg2l_pinctrl_data {
>  	const char * const *port_pins;
>  	const u64 *port_pin_configs;
> @@ -251,6 +253,7 @@ struct rzg2l_pinctrl_data {
>  	const struct rzg2l_hwcfg *hwcfg;
>  	const u64 *variable_pin_cfg;
>  	unsigned int n_variable_pin_cfg;
> +	void (*pwpr_pfc_lock_unlock)(struct rzg2l_pinctrl *pctrl, bool lock);
>  };
>  
>  /**
> @@ -383,7 +386,6 @@ static const u64 r9a07g043f_variable_pin_cfg[] = {
>  static void rzg2l_pinctrl_set_pfc_mode(struct rzg2l_pinctrl *pctrl,
>  				       u8 pin, u8 off, u8 func)
>  {
> -	const struct rzg2l_register_offsets *regs = &pctrl->data->hwcfg->regs;
>  	unsigned long flags;
>  	u32 reg;
>  
> @@ -394,27 +396,23 @@ static void rzg2l_pinctrl_set_pfc_mode(struct rzg2l_pinctrl *pctrl,
>  	reg &= ~(PM_MASK << (pin * 2));
>  	writew(reg, pctrl->base + PM(off));
>  
> +	pctrl->data->pwpr_pfc_lock_unlock(pctrl, false);
> +
>  	/* Temporarily switch to GPIO mode with PMC register */
>  	reg = readb(pctrl->base + PMC(off));
>  	writeb(reg & ~BIT(pin), pctrl->base + PMC(off));
>  
> -	/* Set the PWPR register to allow PFC register to write */
> -	writel(0x0, pctrl->base + regs->pwpr);		/* BOWI=0, PFCWE=0 */
> -	writel(PWPR_PFCWE, pctrl->base + regs->pwpr);	/* BOWI=0, PFCWE=1 */
> -
>  	/* Select Pin function mode with PFC register */
>  	reg = readl(pctrl->base + PFC(off));
>  	reg &= ~(PFC_MASK << (pin * 4));
>  	writel(reg | (func << (pin * 4)), pctrl->base + PFC(off));
>  
> -	/* Set the PWPR register to be write-protected */
> -	writel(0x0, pctrl->base + regs->pwpr);		/* BOWI=0, PFCWE=0 */
> -	writel(PWPR_BOWI, pctrl->base + regs->pwpr);	/* BOWI=1, PFCWE=0 */
> -
>  	/* Switch to Peripheral pin function with PMC register */
>  	reg = readb(pctrl->base + PMC(off));
>  	writeb(reg | BIT(pin), pctrl->base + PMC(off));
>  
> +	pctrl->data->pwpr_pfc_lock_unlock(pctrl, true);
> +
>  	spin_unlock_irqrestore(&pctrl->lock, flags);
>  };
>  
> @@ -2439,12 +2437,8 @@ static void rzg2l_pinctrl_pm_setup_dedicated_regs(struct rzg2l_pinctrl *pctrl, b
>  static void rzg2l_pinctrl_pm_setup_pfc(struct rzg2l_pinctrl *pctrl)
>  {
>  	u32 nports = pctrl->data->n_port_pins / RZG2L_PINS_PER_PORT;
> -	const struct rzg2l_hwcfg *hwcfg = pctrl->data->hwcfg;
> -	const struct rzg2l_register_offsets *regs = &hwcfg->regs;
>  
> -	/* Set the PWPR register to allow PFC register to write. */
> -	writel(0x0, pctrl->base + regs->pwpr);		/* BOWI=0, PFCWE=0 */
> -	writel(PWPR_PFCWE, pctrl->base + regs->pwpr);	/* BOWI=0, PFCWE=1 */
> +	pctrl->data->pwpr_pfc_lock_unlock(pctrl, false);
>  
>  	/* Restore port registers. */
>  	for (u32 port = 0; port < nports; port++) {
> @@ -2487,9 +2481,7 @@ static void rzg2l_pinctrl_pm_setup_pfc(struct rzg2l_pinctrl *pctrl)
>  		}
>  	}
>  
> -	/* Set the PWPR register to be write-protected. */
> -	writel(0x0, pctrl->base + regs->pwpr);		/* BOWI=0, PFCWE=0 */
> -	writel(PWPR_BOWI, pctrl->base + regs->pwpr);	/* BOWI=1, PFCWE=0 */
> +	pctrl->data->pwpr_pfc_lock_unlock(pctrl, true);
>  }
>  
>  static int rzg2l_pinctrl_suspend_noirq(struct device *dev)
> @@ -2551,6 +2543,21 @@ static int rzg2l_pinctrl_resume_noirq(struct device *dev)
>  	return 0;
>  }
>  
> +static void rzg2l_pwpr_pfc_lock_unlock(struct rzg2l_pinctrl *pctrl, bool lock)
> +{
> +	const struct rzg2l_register_offsets *regs = &pctrl->data->hwcfg->regs;
> +
> +	if (lock) {
> +		/* Set the PWPR register to be write-protected */
> +		writel(0x0, pctrl->base + regs->pwpr);		/* BOWI=0, PFCWE=0 */
> +		writel(PWPR_BOWI, pctrl->base + regs->pwpr);	/* BOWI=1, PFCWE=0 */
> +	} else {
> +		/* Set the PWPR register to allow PFC register to write */
> +		writel(0x0, pctrl->base + regs->pwpr);		/* BOWI=0, PFCWE=0 */
> +		writel(PWPR_PFCWE, pctrl->base + regs->pwpr);	/* BOWI=0, PFCWE=1 */
> +	}
> +}
> +
>  static const struct rzg2l_hwcfg rzg2l_hwcfg = {
>  	.regs = {
>  		.pwpr = 0x3014,
> @@ -2608,6 +2615,7 @@ static struct rzg2l_pinctrl_data r9a07g043_data = {
>  	.variable_pin_cfg = r9a07g043f_variable_pin_cfg,
>  	.n_variable_pin_cfg = ARRAY_SIZE(r9a07g043f_variable_pin_cfg),
>  #endif
> +	.pwpr_pfc_lock_unlock = &rzg2l_pwpr_pfc_lock_unlock,
>  };
>  
>  static struct rzg2l_pinctrl_data r9a07g044_data = {
> @@ -2619,6 +2627,7 @@ static struct rzg2l_pinctrl_data r9a07g044_data = {
>  	.n_dedicated_pins = ARRAY_SIZE(rzg2l_dedicated_pins.common) +
>  		ARRAY_SIZE(rzg2l_dedicated_pins.rzg2l_pins),
>  	.hwcfg = &rzg2l_hwcfg,
> +	.pwpr_pfc_lock_unlock = &rzg2l_pwpr_pfc_lock_unlock,
>  };
>  
>  static struct rzg2l_pinctrl_data r9a08g045_data = {
> @@ -2629,6 +2638,7 @@ static struct rzg2l_pinctrl_data r9a08g045_data = {
>  	.n_port_pins = ARRAY_SIZE(r9a08g045_gpio_configs) * RZG2L_PINS_PER_PORT,
>  	.n_dedicated_pins = ARRAY_SIZE(rzg3s_dedicated_pins),
>  	.hwcfg = &rzg3s_hwcfg,
> +	.pwpr_pfc_lock_unlock = &rzg2l_pwpr_pfc_lock_unlock,
>  };
>  
>  static const struct of_device_id rzg2l_pinctrl_of_table[] = {