RE: [PATCH v2 06/13] pinctrl: renesas: pinctrl-rzg2l: Add function pointers for locking/unlocking the PFC register

[Biju Das <biju.das.jz@xxxxxxxxxxxxxx>]

Hi Prabhakar,

Thanks for the patch.

> -----Original Message-----
> From: Prabhakar <prabhakar.csengg@xxxxxxxxx>
> Sent: Tuesday, April 23, 2024 6:59 PM
> Subject: [PATCH v2 06/13] pinctrl: renesas: pinctrl-rzg2l: Add function pointers for
> locking/unlocking the PFC register
> 
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> 
> 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 set_pfc_mode() and
> pm_set_pfc() function pointers.
> 
> Note, in rzg2l_pinctrl_set_pfc_mode() the pwpr_pfc_unlock() call is now called before PMC
> read/write and pwpr_pfc_lock() call is now called after PMC read/write this is to keep changes
> minimal for RZ/V2H(P).
> 
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> ---
> RFC->v2
> - Introduced function pointer for (un)lock
> ---
>  drivers/pinctrl/renesas/pinctrl-rzg2l.c | 51 ++++++++++++++++---------
>  1 file changed, 34 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/pinctrl/renesas/pinctrl-rzg2l.c b/drivers/pinctrl/renesas/pinctrl-rzg2l.c
> index bec4685b4681..0840fda7ca69 100644
> --- a/drivers/pinctrl/renesas/pinctrl-rzg2l.c
> +++ b/drivers/pinctrl/renesas/pinctrl-rzg2l.c
> @@ -246,6 +246,8 @@ struct rzg2l_variable_pin_cfg {
>  	u64 pin:3;
>  };
> 
> +struct rzg2l_pinctrl;
> +
>  struct rzg2l_pinctrl_data {
>  	const char * const *port_pins;
>  	const u64 *port_pin_configs;
> @@ -256,6 +258,8 @@ struct rzg2l_pinctrl_data {
>  	const struct rzg2l_hwcfg *hwcfg;
>  	const struct rzg2l_variable_pin_cfg *variable_pin_cfg;
>  	unsigned int n_variable_pin_cfg;
> +	void (*pwpr_pfc_unlock)(struct rzg2l_pinctrl *pctrl);
> +	void (*pwpr_pfc_lock)(struct rzg2l_pinctrl *pctrl);
>  };
> 
>  /**
> @@ -462,7 +466,6 @@ static const struct rzg2l_variable_pin_cfg 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;
> 
> @@ -473,27 +476,23 @@ 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_unlock(pctrl);
> +
>  	/* 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);		/* B0WI=0, PFCWE=0 */
> -	writel(PWPR_PFCWE, pctrl->base + regs->pwpr);	/* B0WI=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);		/* B0WI=0, PFCWE=0 */
> -	writel(PWPR_B0WI, pctrl->base + regs->pwpr);	/* B0WI=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(pctrl);
> +
>  	spin_unlock_irqrestore(&pctrl->lock, flags);  };
> 
> @@ -2519,12 +2518,8 @@ 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);		/* B0WI=0, PFCWE=0 */
> -	writel(PWPR_PFCWE, pctrl->base + regs->pwpr);	/* B0WI=0, PFCWE=1 */
> +	pctrl->data->pwpr_pfc_unlock(pctrl);
> 
>  	/* Restore port registers. */
>  	for (u32 port = 0; port < nports; port++) { @@ -2567,9 +2562,7 @@ 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);		/* B0WI=0, PFCWE=0 */
> -	writel(PWPR_B0WI, pctrl->base + regs->pwpr);	/* B0WI=1, PFCWE=0 */
> +	pctrl->data->pwpr_pfc_lock(pctrl);
>  }
> 
>  static int rzg2l_pinctrl_suspend_noirq(struct device *dev) @@ -2631,6 +2624,24 @@ static int
> rzg2l_pinctrl_resume_noirq(struct device *dev)
>  	return 0;
>  }
> 
> +static void rzg2l_pwpr_pfc_unlock(struct rzg2l_pinctrl *pctrl) {
> +	const struct rzg2l_register_offsets *regs = &pctrl->data->hwcfg->regs;
> +
> +	/* Set the PWPR register to allow PFC register to write */
> +	writel(0x0, pctrl->base + regs->pwpr);		/* B0WI=0, PFCWE=0 */
> +	writel(PWPR_PFCWE, pctrl->base + regs->pwpr);	/* B0WI=0, PFCWE=1 */
> +}
> +
> +static void rzg2l_pwpr_pfc_lock(struct rzg2l_pinctrl *pctrl) {
> +	const struct rzg2l_register_offsets *regs = &pctrl->data->hwcfg->regs;
> +
> +	/* Set the PWPR register to be write-protected */
> +	writel(0x0, pctrl->base + regs->pwpr);		/* B0WI=0, PFCWE=0 */
> +	writel(PWPR_B0WI, pctrl->base + regs->pwpr);	/* B0WI=1, PFCWE=0 */
> +}
> +
>  static const struct rzg2l_hwcfg rzg2l_hwcfg = {
>  	.regs = {
>  		.pwpr = 0x3014,
> @@ -2688,6 +2699,8 @@ 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_unlock = &rzg2l_pwpr_pfc_unlock,
> +	.pwpr_pfc_lock = &rzg2l_pwpr_pfc_lock,
>  };
> 
>  static struct rzg2l_pinctrl_data r9a07g044_data = { @@ -2699,6 +2712,8 @@ 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_unlock = &rzg2l_pwpr_pfc_unlock,
> +	.pwpr_pfc_lock = &rzg2l_pwpr_pfc_lock,
>  };
> 
>  static struct rzg2l_pinctrl_data r9a08g045_data = { @@ -2709,6 +2724,8 @@ 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_unlock = &rzg2l_pwpr_pfc_unlock,
> +	.pwpr_pfc_lock = &rzg2l_pwpr_pfc_lock,

Some memory can be saved by avoiding duplication of data by using
a single pointer for structure containing function pointers??

struct rzg2l_pinctrl_fns {
	void (*pwpr_pfc_unlock)(struct rzg2l_pinctrl *pctrl);
	void (*pwpr_pfc_lock)(struct rzg2l_pinctrl *pctrl);
}

Cheers,
Biju

>  };
> 
>  static const struct of_device_id rzg2l_pinctrl_of_table[] = {
> --
> 2.34.1