[PATCH v2 6/9] pci: brcmstb: Get and use bridge and rescal reset properties

[Neil Armstrong]

On 4/28/26 18:39, Torsten Duwe wrote:
> From: Torsten Duwe <duwe at suse.de>
> 
> Check whether the device tree has nodes for the two reset controls and use
> them if so.
> 
> Signed-off-by: Torsten Duwe <duwe at suse.de>
> Co-authored-by: Oleksii Moisieiev <oleksii_moisieiev at epam.com>
> Tested-by: Pedro Falcato <pfalcato at suse.de>
> 
> ---
>   drivers/pci/pcie_brcmstb.c | 51 +++++++++++++++++++++++++++++++++++++-
>   1 file changed, 50 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/pci/pcie_brcmstb.c b/drivers/pci/pcie_brcmstb.c
> index 261f8790528..1f97cda5cc7 100644
> --- a/drivers/pci/pcie_brcmstb.c
> +++ b/drivers/pci/pcie_brcmstb.c
> @@ -21,6 +21,7 @@
>   #include <linux/bitfield.h>
>   #include <linux/log2.h>
>   #include <linux/iopoll.h>
> +#include <reset.h>
>   
>   /* PCIe parameters */
>   #define BRCM_NUM_PCIE_OUT_WINS				4
> @@ -83,6 +84,8 @@ struct brcm_pcie {
>   
>   	int			gen;
>   	bool			ssc;
> +	struct reset_ctl	rescal;
> +	struct reset_ctl	bridge_reset;
>   	const struct brcm_pcie_cfg_data *pcie_cfg;
>   };
>   
> @@ -147,6 +150,34 @@ static void brcm_pcie_perst_set_2712(struct brcm_pcie *pcie, u32 val)
>   	writel(tmp, pcie->base + PCIE_MISC_PCIE_CTRL);
>   }
>   
> +static void brcm_pcie_get_resets_dt(struct udevice *dev)
> +{
> +	struct brcm_pcie *pcie = dev_get_priv(dev);
> +	int ret;
> +
> +	ret = reset_get_by_name(dev, "rescal", &pcie->rescal);
> +	if (ret) {
> +		printf("Unable to get rescal reset\n");
> +		return;

Why don't you return the return value ?

> +	}
> +
> +	ret = reset_get_by_name(dev, "bridge", &pcie->bridge_reset);
> +	if (ret) {
> +		printf("Unable to get bridge reset\n");
> +		return;
> +	}
> +}
> +
> +static void brcm_pcie_do_reset(struct udevice *dev)
> +{
> +	struct brcm_pcie *pcie = dev_get_priv(dev);
> +	int ret;
> +
> +	ret = reset_deassert(&pcie->rescal);
> +	if (ret)
> +		printf("failed to deassert 'rescal'\n");

Ditto

> +}
> +
>   static void brcm_pcie_bridge_sw_init_set_generic(struct brcm_pcie *pcie, u32 val)
>   {
>   	if (val)
> @@ -157,6 +188,14 @@ static void brcm_pcie_bridge_sw_init_set_generic(struct brcm_pcie *pcie, u32 val
>   			     RGR1_SW_INIT_1_INIT_MASK);
>   }
>   
> +static void brcm_pcie_bridge_sw_init_set_2712(struct brcm_pcie *pcie, u32 val)
> +{
> +	if (val)
> +		reset_assert(&pcie->bridge_reset);
> +	else
> +		reset_deassert(&pcie->bridge_reset);

Ditto

> +}
> +
>   /**
>    * brcm_pcie_link_up() - Check whether the PCIe link is up
>    * @pcie: Pointer to the PCIe controller state
> @@ -413,6 +452,12 @@ static int brcm_pcie_probe(struct udevice *dev)
>   	u16 nlw, cls, lnksta;
>   	u32 tmp;
>   
> +	/*
> +	 * Ensure rescal reset for BCM2712 is really disabled.
> +	 */
> +	if (pcie->pcie_cfg->type == BCM2712)
> +		brcm_pcie_do_reset(dev);

Ditto

> +
>   	/*
>   	 * Reset the bridge, assert the fundamental reset. Note for some SoCs,
>   	 * e.g. BCM7278, the fundamental reset should not be asserted here.
> @@ -611,6 +656,10 @@ static int brcm_pcie_of_to_plat(struct udevice *dev)
>   		pcie->gen = max_link_speed;
>   
>   	pcie->pcie_cfg = (const struct brcm_pcie_cfg_data *)dev_get_driver_data(dev);
> +
> +	if (pcie->pcie_cfg->type == BCM2712)
> +		brcm_pcie_get_resets_dt(dev);

Ditto

> +
>   	return 0;
>   }
>   
> @@ -645,7 +694,7 @@ static const struct brcm_pcie_cfg_data bcm2712_cfg = {
>   	.offsets	= pcie_offsets_bcm2712,
>   	.type		= BCM2712,
>   	.perst_set	= brcm_pcie_perst_set_2712,
> -	.bridge_sw_init_set = brcm_pcie_bridge_sw_init_set_generic,
> +	.bridge_sw_init_set = brcm_pcie_bridge_sw_init_set_2712,

Can't you mimic linux and check for the reset in brcm_pcie_bridge_sw_init_set_generic ?

>   	.rc_mode	= brcm_pcie_rc_mode,
>   };
>   

Thanks,
Neil