diff mbox series

[v6,4/4] PCI: layerscape: Add suspend/resume for ls1043a

Message ID 20231204160829.2498703-5-Frank.Li@nxp.com (mailing list archive)
State Handled Elsewhere, archived
Headers show
Series PCI: layerscape: Add suspend/resume support for ls1043 and ls1021 | expand

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Commit Message

Frank Li Dec. 4, 2023, 4:08 p.m. UTC 
Add suspend/resume support for Layerscape LS1043a.

In the suspend path, PME_Turn_Off message is sent to the endpoint to
transition the link to L2/L3_Ready state. In this SoC, there is no way to
check if the controller has received the PME_To_Ack from the endpoint or
not. So to be on the safer side, the driver just waits for
PCIE_PME_TO_L2_TIMEOUT_US before asserting the SoC specific PMXMTTURNOFF
bit to complete the PME_Turn_Off handshake. Then the link would enter L2/L3
state depending on the VAUX supply.

In the resume path, the link is brought back from L2 to L0 by doing a
software reset.

Acked-by: Roy Zang <Roy.Zang@nxp.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
---

Notes:
    Chagne from v5 to v6
    - none
    Change from v4 to v5
    - update commit message
    - use comments
    /* Reset the PEX wrapper to bring the link out of L2 */
    
    Change from v3 to v4
    - Call scfg_pcie_send_turnoff_msg() shared with ls1021a
    - update commit message
    
    Change from v2 to v3
    - Remove ls_pcie_lut_readl(writel) function
    
    Change from v1 to v2
    - Update subject 'a' to 'A'

 drivers/pci/controller/dwc/pci-layerscape.c | 63 ++++++++++++++++++++-
 1 file changed, 62 insertions(+), 1 deletion(-)

Comments

Frank Li Dec. 11, 2023, 10:06 p.m. UTC | #1 
On Mon, Dec 04, 2023 at 11:08:29AM -0500, Frank Li wrote:
> Add suspend/resume support for Layerscape LS1043a.
> 
> In the suspend path, PME_Turn_Off message is sent to the endpoint to
> transition the link to L2/L3_Ready state. In this SoC, there is no way to
> check if the controller has received the PME_To_Ack from the endpoint or
> not. So to be on the safer side, the driver just waits for
> PCIE_PME_TO_L2_TIMEOUT_US before asserting the SoC specific PMXMTTURNOFF
> bit to complete the PME_Turn_Off handshake. Then the link would enter L2/L3
> state depending on the VAUX supply.
> 
> In the resume path, the link is brought back from L2 to L0 by doing a
> software reset.
> 
> Acked-by: Roy Zang <Roy.Zang@nxp.com>
> Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> Signed-off-by: Frank Li <Frank.Li@nxp.com>

@Lorenzo:

   Could you please pick up these patches? Mani already reviewed and only
impact layerscape platform.

Frank

> ---
> 
> Notes:
>     Chagne from v5 to v6
>     - none
>     Change from v4 to v5
>     - update commit message
>     - use comments
>     /* Reset the PEX wrapper to bring the link out of L2 */
>     
>     Change from v3 to v4
>     - Call scfg_pcie_send_turnoff_msg() shared with ls1021a
>     - update commit message
>     
>     Change from v2 to v3
>     - Remove ls_pcie_lut_readl(writel) function
>     
>     Change from v1 to v2
>     - Update subject 'a' to 'A'
> 
>  drivers/pci/controller/dwc/pci-layerscape.c | 63 ++++++++++++++++++++-
>  1 file changed, 62 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/pci/controller/dwc/pci-layerscape.c b/drivers/pci/controller/dwc/pci-layerscape.c
> index f3dfb70066fb7..7cdada200de7e 100644
> --- a/drivers/pci/controller/dwc/pci-layerscape.c
> +++ b/drivers/pci/controller/dwc/pci-layerscape.c
> @@ -41,6 +41,15 @@
>  #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 {
> @@ -224,6 +233,45 @@ static int ls1021a_pcie_exit_from_l2(struct dw_pcie_rp *pp)
>  	return scfg_pcie_exit_from_l2(pcie->scfg, SCFG_PEXSFTRSTCR, PEXSR(pcie->index));
>  }
>  
> +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);
> +
> +	scfg_pcie_send_turnoff_msg(pcie->scfg, SCFG_PEXPMECR, PEXPME(pcie->index));
> +}
> +
> +static int 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;
> +
> +	/*
> +	 * Reset the PEX wrapper to bring the link out of L2.
> +	 * LDBG_WE: allows the user to have write access to the PEXDBG[SR] for both setting and
> +	 *	    clearing the soft reset on the PEX module.
> +	 * LDBG_SR: When SR is set to 1, the PEX module enters soft reset.
> +	 */
> +	val = ls_pcie_pf_lut_readl(pcie, LS_PCIE_LDBG);
> +	val |= LDBG_WE;
> +	ls_pcie_pf_lut_writel(pcie, LS_PCIE_LDBG, val);
> +
> +	val = ls_pcie_pf_lut_readl(pcie, LS_PCIE_LDBG);
> +	val |= LDBG_SR;
> +	ls_pcie_pf_lut_writel(pcie, LS_PCIE_LDBG, val);
> +
> +	val = ls_pcie_pf_lut_readl(pcie, LS_PCIE_LDBG);
> +	val &= ~LDBG_SR;
> +	ls_pcie_pf_lut_writel(pcie, LS_PCIE_LDBG, val);
> +
> +	val = ls_pcie_pf_lut_readl(pcie, LS_PCIE_LDBG);
> +	val &= ~LDBG_WE;
> +	ls_pcie_pf_lut_writel(pcie, LS_PCIE_LDBG, val);
> +
> +	return 0;
> +}
> +
>  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,
> @@ -241,6 +289,19 @@ 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 = ls_pcie_host_init,
> +	.pme_turn_off = ls1043a_pcie_send_turnoff_msg,
> +};
> +
> +static const struct ls_pcie_drvdata ls1043a_drvdata = {
> +	.pf_lut_off = 0x10000,
> +	.pm_support = true,
> +	.scfg_support = true,
> +	.ops = &ls1043a_pcie_host_ops,
> +	.exit_from_l2 = ls1043a_pcie_exit_from_l2,
> +};
> +
>  static const struct ls_pcie_drvdata layerscape_drvdata = {
>  	.pf_lut_off = 0xc0000,
>  	.pm_support = true,
> @@ -252,7 +313,7 @@ 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 },
> -- 
> 2.34.1
>
diff mbox series

Patch

diff --git a/drivers/pci/controller/dwc/pci-layerscape.c b/drivers/pci/controller/dwc/pci-layerscape.c
index f3dfb70066fb7..7cdada200de7e 100644
--- a/drivers/pci/controller/dwc/pci-layerscape.c
+++ b/drivers/pci/controller/dwc/pci-layerscape.c
@@ -41,6 +41,15 @@ 
 #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 {
@@ -224,6 +233,45 @@  static int ls1021a_pcie_exit_from_l2(struct dw_pcie_rp *pp)
 	return scfg_pcie_exit_from_l2(pcie->scfg, SCFG_PEXSFTRSTCR, PEXSR(pcie->index));
 }
 
+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);
+
+	scfg_pcie_send_turnoff_msg(pcie->scfg, SCFG_PEXPMECR, PEXPME(pcie->index));
+}
+
+static int 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;
+
+	/*
+	 * Reset the PEX wrapper to bring the link out of L2.
+	 * LDBG_WE: allows the user to have write access to the PEXDBG[SR] for both setting and
+	 *	    clearing the soft reset on the PEX module.
+	 * LDBG_SR: When SR is set to 1, the PEX module enters soft reset.
+	 */
+	val = ls_pcie_pf_lut_readl(pcie, LS_PCIE_LDBG);
+	val |= LDBG_WE;
+	ls_pcie_pf_lut_writel(pcie, LS_PCIE_LDBG, val);
+
+	val = ls_pcie_pf_lut_readl(pcie, LS_PCIE_LDBG);
+	val |= LDBG_SR;
+	ls_pcie_pf_lut_writel(pcie, LS_PCIE_LDBG, val);
+
+	val = ls_pcie_pf_lut_readl(pcie, LS_PCIE_LDBG);
+	val &= ~LDBG_SR;
+	ls_pcie_pf_lut_writel(pcie, LS_PCIE_LDBG, val);
+
+	val = ls_pcie_pf_lut_readl(pcie, LS_PCIE_LDBG);
+	val &= ~LDBG_WE;
+	ls_pcie_pf_lut_writel(pcie, LS_PCIE_LDBG, val);
+
+	return 0;
+}
+
 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,
@@ -241,6 +289,19 @@  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 = ls_pcie_host_init,
+	.pme_turn_off = ls1043a_pcie_send_turnoff_msg,
+};
+
+static const struct ls_pcie_drvdata ls1043a_drvdata = {
+	.pf_lut_off = 0x10000,
+	.pm_support = true,
+	.scfg_support = true,
+	.ops = &ls1043a_pcie_host_ops,
+	.exit_from_l2 = ls1043a_pcie_exit_from_l2,
+};
+
 static const struct ls_pcie_drvdata layerscape_drvdata = {
 	.pf_lut_off = 0xc0000,
 	.pm_support = true,
@@ -252,7 +313,7 @@  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 },