Subject: Re: [PATCH 3/3] PCI: layerscape: add suspend/resume for ls1043a

From: Manivannan Sadhasivam <[email-masked]>
Date: Mon, 16 Oct 2023 22:37:06 +0530

On Fri, Sep 15, 2023 at 02:43:06PM -0400, Frank Li wrote:
> ls1043a add suspend/resume support.
> 

Same comment as previous patch for patch description.

> Signed-off-by: Frank Li <[email-masked]>
> ---
>  drivers/pci/controller/dwc/pci-layerscape.c | 91 ++++++++++++++++++++-
>  1 file changed, 90 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/pci/controller/dwc/pci-layerscape.c b/drivers/pci/controller/dwc/pci-layerscape.c
> index bc5a8ff1a26ce..debabb9bb41f4 100644
> --- a/drivers/pci/controller/dwc/pci-layerscape.c
> +++ b/drivers/pci/controller/dwc/pci-layerscape.c
> @@ -41,10 +41,20 @@
>  #define SCFG_PEXSFTRSTCR	0x190
>  #define PEXSR(idx)		BIT(idx)
>  
> +/* LS1043A PEX PME control register */
> +#define SCFG_PEXPMECR		0x144
> +#define PEXPME(idx)		BIT(31 - (idx) * 4)
> +
> +/* LS1043A PEX LUT debug register */
> +#define LS_PCIE_LDBG	0x7fc
> +#define LDBG_SR		BIT(30)
> +#define LDBG_WE		BIT(31)
> +
>  #define PCIE_IATU_NUM		6
>  
>  struct ls_pcie_drvdata {
>  	const u32 pf_off;
> +	const u32 lut_off;
>  	const struct dw_pcie_host_ops *ops;
>  	void (*exit_from_l2)(struct dw_pcie_rp *pp);
>  	bool pm_support;
> @@ -54,6 +64,7 @@ struct ls_pcie {
>  	struct dw_pcie *pci;
>  	const struct ls_pcie_drvdata *drvdata;
>  	void __iomem *pf_base;
> +	void __iomem *lut_base;
>  	struct regmap *scfg;
>  	int index;
>  	bool big_endian;
> @@ -116,6 +127,23 @@ static void ls_pcie_pf_writel(struct ls_pcie *pcie, u32 off, u32 val)
>  		iowrite32(val, pcie->pf_base + off);
>  }
>  
> +static u32 ls_pcie_lut_readl(struct ls_pcie *pcie, u32 off)
> +{

Looking at ls_pcie_pf_{readl/writel} you can use a common function that does the
read/write and pass the relevant base/offset. This will avoid code duplication.

> +	if (pcie->big_endian)
> +		return ioread32be(pcie->lut_base + off);
> +
> +	return ioread32(pcie->lut_base + off);
> +}
> +
> +static void ls_pcie_lut_writel(struct ls_pcie *pcie, u32 off, u32 val)
> +{
> +	if (pcie->big_endian)
> +		iowrite32be(val, pcie->lut_base + off);
> +	else
> +		iowrite32(val, pcie->lut_base + off);
> +}
> +

Remove extra newline

> +
>  static void ls_pcie_send_turnoff_msg(struct dw_pcie_rp *pp)
>  {
>  	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> @@ -249,6 +277,54 @@ static int ls1021a_pcie_host_init(struct dw_pcie_rp *pp)
>  	return ret;
>  }
>  
> +static void ls1043a_pcie_send_turnoff_msg(struct dw_pcie_rp *pp)
> +{
> +	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> +	struct ls_pcie *pcie = to_ls_pcie(pci);
> +	u32 val;
> +
> +	if (!pcie->scfg) {
> +		dev_dbg(pcie->pci->dev, "SYSCFG is NULL\n");
> +		return;
> +	}
> +
> +	/* Send Turn_off message */
> +	regmap_read(pcie->scfg, SCFG_PEXPMECR, &val);

If the register offset is the only difference, then you could pass the register
offset via drvdata and use the same functions.

> +	val |= PEXPME(pcie->index);
> +	regmap_write(pcie->scfg, SCFG_PEXPMECR, val);
> +
> +	/* There are not register to check ACK, so wait PCIE_PME_TO_L2_TIMEOUT_US */
> +	mdelay(PCIE_PME_TO_L2_TIMEOUT_US/1000);
> +
> +	/* Clear Turn_off message */
> +	regmap_read(pcie->scfg, SCFG_PEXPMECR, &val);
> +	val &= ~PEXPME(pcie->index);
> +	regmap_write(pcie->scfg, SCFG_PEXPMECR, val);
> +}
> +
> +static void ls1043a_pcie_exit_from_l2(struct dw_pcie_rp *pp)
> +{
> +	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> +	struct ls_pcie *pcie = to_ls_pcie(pci);
> +	u32 val;
> +

Again, a comment here would be useful.

- Mani

> +	val = ls_pcie_lut_readl(pcie, LS_PCIE_LDBG);
> +	val |= LDBG_WE;
> +	ls_pcie_lut_writel(pcie, LS_PCIE_LDBG, val);
> +
> +	val = ls_pcie_lut_readl(pcie, LS_PCIE_LDBG);
> +	val |= LDBG_SR;
> +	ls_pcie_lut_writel(pcie, LS_PCIE_LDBG, val);
> +
> +	val = ls_pcie_lut_readl(pcie, LS_PCIE_LDBG);
> +	val &= ~LDBG_SR;
> +	ls_pcie_lut_writel(pcie, LS_PCIE_LDBG, val);
> +
> +	val = ls_pcie_lut_readl(pcie, LS_PCIE_LDBG);
> +	val &= ~LDBG_WE;
> +	ls_pcie_lut_writel(pcie, LS_PCIE_LDBG, val);
> +}
> +
>  static const struct dw_pcie_host_ops ls_pcie_host_ops = {
>  	.host_init = ls_pcie_host_init,
>  	.pme_turn_off = ls_pcie_send_turnoff_msg,
> @@ -265,6 +341,18 @@ static const struct ls_pcie_drvdata ls1021a_drvdata = {
>  	.exit_from_l2 = ls1021a_pcie_exit_from_l2,
>  };
>  
> +static const struct dw_pcie_host_ops ls1043a_pcie_host_ops = {
> +	.host_init = ls1021a_pcie_host_init, /* the same as ls1021 */
> +	.pme_turn_off = ls1043a_pcie_send_turnoff_msg,
> +};
> +
> +static const struct ls_pcie_drvdata ls1043a_drvdata = {
> +	.lut_off = 0x10000,
> +	.pm_support = true,
> +	.ops = &ls1043a_pcie_host_ops,
> +	.exit_from_l2 = ls1043a_pcie_exit_from_l2,
> +};
> +
>  static const struct ls_pcie_drvdata layerscape_drvdata = {
>  	.pf_off = 0xc0000,
>  	.pm_support = true,
> @@ -275,7 +363,7 @@ static const struct of_device_id ls_pcie_of_match[] = {
>  	{ .compatible = "fsl,ls1012a-pcie", .data = &layerscape_drvdata },
>  	{ .compatible = "fsl,ls1021a-pcie", .data = &ls1021a_drvdata },
>  	{ .compatible = "fsl,ls1028a-pcie", .data = &layerscape_drvdata },
> -	{ .compatible = "fsl,ls1043a-pcie", .data = &ls1021a_drvdata },
> +	{ .compatible = "fsl,ls1043a-pcie", .data = &ls1043a_drvdata },
>  	{ .compatible = "fsl,ls1046a-pcie", .data = &layerscape_drvdata },
>  	{ .compatible = "fsl,ls2080a-pcie", .data = &layerscape_drvdata },
>  	{ .compatible = "fsl,ls2085a-pcie", .data = &layerscape_drvdata },
> @@ -314,6 +402,7 @@ static int ls_pcie_probe(struct platform_device *pdev)
>  	pcie->big_endian = of_property_read_bool(dev->of_node, "big-endian");
>  
>  	pcie->pf_base = pci->dbi_base + pcie->drvdata->pf_off;
> +	pcie->lut_base = pci->dbi_base + pcie->drvdata->lut_off;
>  
>  	if (!ls_pcie_is_bridge(pcie))
>  		return -ENODEV;
> -- 
> 2.34.1
> 

-- 
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