Enable PCI suspend/resume support on imx6sx socs. This is similar to
imx7d with a few differences:
* The PM_Turn_Off bit is exposed through an IOMUX GPR, like all other
pcie control bits on 6sx.
* The pcie_inbound_axi clk needs to be turned off in suspend. On resume
it is restored via resume -> deassert_core_reset -> enable_ref_clk.
Most of the resume logic is shared with the initial reset after probe.
Signed-off-by: Leonard Crestez <[email protected]>
---
Changes since v1:
* Use a switch statement in imx6_pcie_pm_turnoff. The DT-based turnoff
path is still an if statement.
* Did not split imx6_pcie_clk_disable or call it from other paths, this
would bring complications and is somewhat unrelated.
* See v1 comments: https://lore.kernel.org/patchwork/patch/996806/
drivers/pci/controller/dwc/pci-imx6.c | 44 ++++++++++++++++++---
include/linux/mfd/syscon/imx6q-iomuxc-gpr.h | 1 +
2 files changed, 40 insertions(+), 5 deletions(-)
diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index 2cbef2d7c207..54625569d0bc 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -771,41 +771,75 @@ static void imx6_pcie_ltssm_disable(struct device *dev)
}
}
static void imx6_pcie_pm_turnoff(struct imx6_pcie *imx6_pcie)
{
- reset_control_assert(imx6_pcie->turnoff_reset);
- reset_control_deassert(imx6_pcie->turnoff_reset);
+ struct device *dev = imx6_pcie->pci->dev;
+
+ /* Some variants have a turnoff reset in DT */
+ if (imx6_pcie->turnoff_reset) {
+ reset_control_assert(imx6_pcie->turnoff_reset);
+ reset_control_deassert(imx6_pcie->turnoff_reset);
+ goto pm_turnoff_sleep;
+ }
+
+ /* Others poke directly at IOMUXC registers */
+ switch (imx6_pcie->variant) {
+ case IMX6SX:
+ regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
+ IMX6SX_GPR12_PCIE_PM_TURN_OFF,
+ IMX6SX_GPR12_PCIE_PM_TURN_OFF);
+ regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
+ IMX6SX_GPR12_PCIE_PM_TURN_OFF, 0);
+ break;
+ default:
+ dev_err(dev, "PME_Turn_Off not implemented\n");
+ return;
+ }
/*
* Components with an upstream port must respond to
* PME_Turn_Off with PME_TO_Ack but we can't check.
*
* The standard recommends a 1-10ms timeout after which to
* proceed anyway as if acks were received.
*/
+pm_turnoff_sleep:
usleep_range(1000, 10000);
}
static void imx6_pcie_clk_disable(struct imx6_pcie *imx6_pcie)
{
clk_disable_unprepare(imx6_pcie->pcie);
clk_disable_unprepare(imx6_pcie->pcie_phy);
clk_disable_unprepare(imx6_pcie->pcie_bus);
- if (imx6_pcie->variant == IMX7D) {
+ switch (imx6_pcie->variant) {
+ case IMX6SX:
+ clk_disable_unprepare(imx6_pcie->pcie_inbound_axi);
+ break;
+ case IMX7D:
regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
IMX7D_GPR12_PCIE_PHY_REFCLK_SEL,
IMX7D_GPR12_PCIE_PHY_REFCLK_SEL);
+ break;
+ default:
+ break;
}
}
+static inline bool imx6_pcie_supports_suspend(struct imx6_pcie *imx6_pcie)
+{
+ return (imx6_pcie->variant == IMX7D ||
+ imx6_pcie->variant == IMX6SX);
+}
+
static int imx6_pcie_suspend_noirq(struct device *dev)
{
struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
- if (imx6_pcie->variant != IMX7D)
+ if (!imx6_pcie_supports_suspend(imx6_pcie))
return 0;
imx6_pcie_pm_turnoff(imx6_pcie);
imx6_pcie_clk_disable(imx6_pcie);
imx6_pcie_ltssm_disable(dev);
@@ -817,11 +851,11 @@ static int imx6_pcie_resume_noirq(struct device *dev)
{
int ret;
struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
struct pcie_port *pp = &imx6_pcie->pci->pp;
- if (imx6_pcie->variant != IMX7D)
+ if (!imx6_pcie_supports_suspend(imx6_pcie))
return 0;
imx6_pcie_assert_core_reset(imx6_pcie);
imx6_pcie_init_phy(imx6_pcie);
imx6_pcie_deassert_core_reset(imx6_pcie);
diff --git a/include/linux/mfd/syscon/imx6q-iomuxc-gpr.h b/include/linux/mfd/syscon/imx6q-iomuxc-gpr.h
index 6c1ad160ed87..c1b25f5e386d 100644
--- a/include/linux/mfd/syscon/imx6q-iomuxc-gpr.h
+++ b/include/linux/mfd/syscon/imx6q-iomuxc-gpr.h
@@ -438,10 +438,11 @@
#define IMX6SX_GPR5_DISP_MUX_DCIC1_LCDIF1 (0x0 << 1)
#define IMX6SX_GPR5_DISP_MUX_DCIC1_LVDS (0x1 << 1)
#define IMX6SX_GPR5_DISP_MUX_DCIC1_MASK (0x1 << 1)
#define IMX6SX_GPR12_PCIE_TEST_POWERDOWN BIT(30)
+#define IMX6SX_GPR12_PCIE_PM_TURN_OFF BIT(16)
#define IMX6SX_GPR12_PCIE_RX_EQ_MASK (0x7 << 0)
#define IMX6SX_GPR12_PCIE_RX_EQ_2 (0x2 << 0)
/* For imx6ul iomux gpr register field define */
#define IMX6UL_GPR1_ENET1_CLK_DIR (0x1 << 17)
--
2.17.1
On Wed, Nov 7, 2018 at 5:57 AM Leonard Crestez <[email protected]> wrote:
>
> Enable PCI suspend/resume support on imx6sx socs. This is similar to
> imx7d with a few differences:
>
> * The PM_Turn_Off bit is exposed through an IOMUX GPR, like all other
> pcie control bits on 6sx.
> * The pcie_inbound_axi clk needs to be turned off in suspend. On resume
> it is restored via resume -> deassert_core_reset -> enable_ref_clk.
>
> Most of the resume logic is shared with the initial reset after probe.
>
> Signed-off-by: Leonard Crestez <[email protected]>
>
> ---
> Changes since v1:
> * Use a switch statement in imx6_pcie_pm_turnoff. The DT-based turnoff
> path is still an if statement.
> * Did not split imx6_pcie_clk_disable or call it from other paths, this
> would bring complications and is somewhat unrelated.
> * See v1 comments: https://lore.kernel.org/patchwork/patch/996806/
>
> drivers/pci/controller/dwc/pci-imx6.c | 44 ++++++++++++++++++---
> include/linux/mfd/syscon/imx6q-iomuxc-gpr.h | 1 +
> 2 files changed, 40 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
> index 2cbef2d7c207..54625569d0bc 100644
> --- a/drivers/pci/controller/dwc/pci-imx6.c
> +++ b/drivers/pci/controller/dwc/pci-imx6.c
> @@ -771,41 +771,75 @@ static void imx6_pcie_ltssm_disable(struct device *dev)
> }
> }
>
> static void imx6_pcie_pm_turnoff(struct imx6_pcie *imx6_pcie)
> {
> - reset_control_assert(imx6_pcie->turnoff_reset);
> - reset_control_deassert(imx6_pcie->turnoff_reset);
> + struct device *dev = imx6_pcie->pci->dev;
> +
> + /* Some variants have a turnoff reset in DT */
> + if (imx6_pcie->turnoff_reset) {
> + reset_control_assert(imx6_pcie->turnoff_reset);
> + reset_control_deassert(imx6_pcie->turnoff_reset);
> + goto pm_turnoff_sleep;
> + }
> +
> + /* Others poke directly at IOMUXC registers */
> + switch (imx6_pcie->variant) {
> + case IMX6SX:
> + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
> + IMX6SX_GPR12_PCIE_PM_TURN_OFF,
> + IMX6SX_GPR12_PCIE_PM_TURN_OFF);
> + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
> + IMX6SX_GPR12_PCIE_PM_TURN_OFF, 0);
> + break;
> + default:
> + dev_err(dev, "PME_Turn_Off not implemented\n");
> + return;
Purely optionally, if you feel like avoiding goto you can change this to:
default:
if (!imx6_pcie->turnoff_reset) {
dev_err(dev, "PME_Turn_Off not implemented\n");
return;
}
reset_control_assert(imx6_pcie->turnoff_reset);
reset_control_deassert(imx6_pcie->turnoff_reset);
break;
but that's up to you. FWIW, patch looks reasonable:
Reviewed-by: Andrey Smirnov <[email protected]>
> + }
>
> /*
> * Components with an upstream port must respond to
> * PME_Turn_Off with PME_TO_Ack but we can't check.
> *
> * The standard recommends a 1-10ms timeout after which to
> * proceed anyway as if acks were received.
> */
> +pm_turnoff_sleep:
> usleep_range(1000, 10000);
> }
>
> static void imx6_pcie_clk_disable(struct imx6_pcie *imx6_pcie)
> {
> clk_disable_unprepare(imx6_pcie->pcie);
> clk_disable_unprepare(imx6_pcie->pcie_phy);
> clk_disable_unprepare(imx6_pcie->pcie_bus);
>
> - if (imx6_pcie->variant == IMX7D) {
> + switch (imx6_pcie->variant) {
> + case IMX6SX:
> + clk_disable_unprepare(imx6_pcie->pcie_inbound_axi);
> + break;
> + case IMX7D:
> regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
> IMX7D_GPR12_PCIE_PHY_REFCLK_SEL,
> IMX7D_GPR12_PCIE_PHY_REFCLK_SEL);
> + break;
> + default:
> + break;
> }
> }
>
> +static inline bool imx6_pcie_supports_suspend(struct imx6_pcie *imx6_pcie)
> +{
> + return (imx6_pcie->variant == IMX7D ||
> + imx6_pcie->variant == IMX6SX);
> +}
> +
> static int imx6_pcie_suspend_noirq(struct device *dev)
> {
> struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
>
> - if (imx6_pcie->variant != IMX7D)
> + if (!imx6_pcie_supports_suspend(imx6_pcie))
> return 0;
>
> imx6_pcie_pm_turnoff(imx6_pcie);
> imx6_pcie_clk_disable(imx6_pcie);
> imx6_pcie_ltssm_disable(dev);
> @@ -817,11 +851,11 @@ static int imx6_pcie_resume_noirq(struct device *dev)
> {
> int ret;
> struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
> struct pcie_port *pp = &imx6_pcie->pci->pp;
>
> - if (imx6_pcie->variant != IMX7D)
> + if (!imx6_pcie_supports_suspend(imx6_pcie))
> return 0;
>
> imx6_pcie_assert_core_reset(imx6_pcie);
> imx6_pcie_init_phy(imx6_pcie);
> imx6_pcie_deassert_core_reset(imx6_pcie);
> diff --git a/include/linux/mfd/syscon/imx6q-iomuxc-gpr.h b/include/linux/mfd/syscon/imx6q-iomuxc-gpr.h
> index 6c1ad160ed87..c1b25f5e386d 100644
> --- a/include/linux/mfd/syscon/imx6q-iomuxc-gpr.h
> +++ b/include/linux/mfd/syscon/imx6q-iomuxc-gpr.h
> @@ -438,10 +438,11 @@
> #define IMX6SX_GPR5_DISP_MUX_DCIC1_LCDIF1 (0x0 << 1)
> #define IMX6SX_GPR5_DISP_MUX_DCIC1_LVDS (0x1 << 1)
> #define IMX6SX_GPR5_DISP_MUX_DCIC1_MASK (0x1 << 1)
>
> #define IMX6SX_GPR12_PCIE_TEST_POWERDOWN BIT(30)
> +#define IMX6SX_GPR12_PCIE_PM_TURN_OFF BIT(16)
> #define IMX6SX_GPR12_PCIE_RX_EQ_MASK (0x7 << 0)
> #define IMX6SX_GPR12_PCIE_RX_EQ_2 (0x2 << 0)
>
> /* For imx6ul iomux gpr register field define */
> #define IMX6UL_GPR1_ENET1_CLK_DIR (0x1 << 17)
> --
> 2.17.1
>
On Wed, Nov 07, 2018 at 01:57:03PM +0000, Leonard Crestez wrote:
> Enable PCI suspend/resume support on imx6sx socs. This is similar to
> imx7d with a few differences:
>
> * The PM_Turn_Off bit is exposed through an IOMUX GPR, like all other
> pcie control bits on 6sx.
> * The pcie_inbound_axi clk needs to be turned off in suspend. On resume
> it is restored via resume -> deassert_core_reset -> enable_ref_clk.
>
> Most of the resume logic is shared with the initial reset after probe.
>
> Signed-off-by: Leonard Crestez <[email protected]>
>
> ---
> Changes since v1:
> * Use a switch statement in imx6_pcie_pm_turnoff. The DT-based turnoff
> path is still an if statement.
> * Did not split imx6_pcie_clk_disable or call it from other paths, this
> would bring complications and is somewhat unrelated.
> * See v1 comments: https://lore.kernel.org/patchwork/patch/996806/
>
> drivers/pci/controller/dwc/pci-imx6.c | 44 ++++++++++++++++++---
> include/linux/mfd/syscon/imx6q-iomuxc-gpr.h | 1 +
> 2 files changed, 40 insertions(+), 5 deletions(-)
I request Richard/Lucas ACK in order to merge this patch.
Thanks,
Lorenzo
> diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
> index 2cbef2d7c207..54625569d0bc 100644
> --- a/drivers/pci/controller/dwc/pci-imx6.c
> +++ b/drivers/pci/controller/dwc/pci-imx6.c
> @@ -771,41 +771,75 @@ static void imx6_pcie_ltssm_disable(struct device *dev)
> }
> }
>
> static void imx6_pcie_pm_turnoff(struct imx6_pcie *imx6_pcie)
> {
> - reset_control_assert(imx6_pcie->turnoff_reset);
> - reset_control_deassert(imx6_pcie->turnoff_reset);
> + struct device *dev = imx6_pcie->pci->dev;
> +
> + /* Some variants have a turnoff reset in DT */
> + if (imx6_pcie->turnoff_reset) {
> + reset_control_assert(imx6_pcie->turnoff_reset);
> + reset_control_deassert(imx6_pcie->turnoff_reset);
> + goto pm_turnoff_sleep;
> + }
> +
> + /* Others poke directly at IOMUXC registers */
> + switch (imx6_pcie->variant) {
> + case IMX6SX:
> + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
> + IMX6SX_GPR12_PCIE_PM_TURN_OFF,
> + IMX6SX_GPR12_PCIE_PM_TURN_OFF);
> + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
> + IMX6SX_GPR12_PCIE_PM_TURN_OFF, 0);
> + break;
> + default:
> + dev_err(dev, "PME_Turn_Off not implemented\n");
> + return;
> + }
>
> /*
> * Components with an upstream port must respond to
> * PME_Turn_Off with PME_TO_Ack but we can't check.
> *
> * The standard recommends a 1-10ms timeout after which to
> * proceed anyway as if acks were received.
> */
> +pm_turnoff_sleep:
> usleep_range(1000, 10000);
> }
>
> static void imx6_pcie_clk_disable(struct imx6_pcie *imx6_pcie)
> {
> clk_disable_unprepare(imx6_pcie->pcie);
> clk_disable_unprepare(imx6_pcie->pcie_phy);
> clk_disable_unprepare(imx6_pcie->pcie_bus);
>
> - if (imx6_pcie->variant == IMX7D) {
> + switch (imx6_pcie->variant) {
> + case IMX6SX:
> + clk_disable_unprepare(imx6_pcie->pcie_inbound_axi);
> + break;
> + case IMX7D:
> regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
> IMX7D_GPR12_PCIE_PHY_REFCLK_SEL,
> IMX7D_GPR12_PCIE_PHY_REFCLK_SEL);
> + break;
> + default:
> + break;
> }
> }
>
> +static inline bool imx6_pcie_supports_suspend(struct imx6_pcie *imx6_pcie)
> +{
> + return (imx6_pcie->variant == IMX7D ||
> + imx6_pcie->variant == IMX6SX);
> +}
> +
> static int imx6_pcie_suspend_noirq(struct device *dev)
> {
> struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
>
> - if (imx6_pcie->variant != IMX7D)
> + if (!imx6_pcie_supports_suspend(imx6_pcie))
> return 0;
>
> imx6_pcie_pm_turnoff(imx6_pcie);
> imx6_pcie_clk_disable(imx6_pcie);
> imx6_pcie_ltssm_disable(dev);
> @@ -817,11 +851,11 @@ static int imx6_pcie_resume_noirq(struct device *dev)
> {
> int ret;
> struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
> struct pcie_port *pp = &imx6_pcie->pci->pp;
>
> - if (imx6_pcie->variant != IMX7D)
> + if (!imx6_pcie_supports_suspend(imx6_pcie))
> return 0;
>
> imx6_pcie_assert_core_reset(imx6_pcie);
> imx6_pcie_init_phy(imx6_pcie);
> imx6_pcie_deassert_core_reset(imx6_pcie);
> diff --git a/include/linux/mfd/syscon/imx6q-iomuxc-gpr.h b/include/linux/mfd/syscon/imx6q-iomuxc-gpr.h
> index 6c1ad160ed87..c1b25f5e386d 100644
> --- a/include/linux/mfd/syscon/imx6q-iomuxc-gpr.h
> +++ b/include/linux/mfd/syscon/imx6q-iomuxc-gpr.h
> @@ -438,10 +438,11 @@
> #define IMX6SX_GPR5_DISP_MUX_DCIC1_LCDIF1 (0x0 << 1)
> #define IMX6SX_GPR5_DISP_MUX_DCIC1_LVDS (0x1 << 1)
> #define IMX6SX_GPR5_DISP_MUX_DCIC1_MASK (0x1 << 1)
>
> #define IMX6SX_GPR12_PCIE_TEST_POWERDOWN BIT(30)
> +#define IMX6SX_GPR12_PCIE_PM_TURN_OFF BIT(16)
> #define IMX6SX_GPR12_PCIE_RX_EQ_MASK (0x7 << 0)
> #define IMX6SX_GPR12_PCIE_RX_EQ_2 (0x2 << 0)
>
> /* For imx6ul iomux gpr register field define */
> #define IMX6UL_GPR1_ENET1_CLK_DIR (0x1 << 17)
> --
> 2.17.1
>
Am Donnerstag, den 22.11.2018, 11:38 +0000 schrieb Lorenzo Pieralisi:
> On Wed, Nov 07, 2018 at 01:57:03PM +0000, Leonard Crestez wrote:
> > Enable PCI suspend/resume support on imx6sx socs. This is similar to
> > imx7d with a few differences:
> >
> > * The PM_Turn_Off bit is exposed through an IOMUX GPR, like all other
> > pcie control bits on 6sx.
> > * The pcie_inbound_axi clk needs to be turned off in suspend. On resume
> > it is restored via resume -> deassert_core_reset -> enable_ref_clk.
> >
> > Most of the resume logic is shared with the initial reset after probe.
> >
> > > > Signed-off-by: Leonard Crestez <[email protected]>
> >
> > ---
> > Changes since v1:
> > * Use a switch statement in imx6_pcie_pm_turnoff. The DT-based turnoff
> > path is still an if statement.
> > * Did not split imx6_pcie_clk_disable or call it from other paths, this
> > would bring complications and is somewhat unrelated.
> > * See v1 comments: https://lore.kernel.org/patchwork/patch/996806/
> >
> > drivers/pci/controller/dwc/pci-imx6.c | 44 ++++++++++++++++++---
> > include/linux/mfd/syscon/imx6q-iomuxc-gpr.h | 1 +
> > 2 files changed, 40 insertions(+), 5 deletions(-)
>
> I request Richard/Lucas ACK in order to merge this patch.
I'm fine with this patch.
Acked-by: Lucas Stach <[email protected]>
> Thanks,
> Lorenzo
>
> > diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
> > index 2cbef2d7c207..54625569d0bc 100644
> > --- a/drivers/pci/controller/dwc/pci-imx6.c
> > +++ b/drivers/pci/controller/dwc/pci-imx6.c
> > @@ -771,41 +771,75 @@ static void imx6_pcie_ltssm_disable(struct device *dev)
> > > > }
> > }
> >
> > static void imx6_pcie_pm_turnoff(struct imx6_pcie *imx6_pcie)
> > {
> > > > - reset_control_assert(imx6_pcie->turnoff_reset);
> > > > - reset_control_deassert(imx6_pcie->turnoff_reset);
> > > > + struct device *dev = imx6_pcie->pci->dev;
> > +
> > > > + /* Some variants have a turnoff reset in DT */
> > > > + if (imx6_pcie->turnoff_reset) {
> > > > + reset_control_assert(imx6_pcie->turnoff_reset);
> > > > + reset_control_deassert(imx6_pcie->turnoff_reset);
> > > > + goto pm_turnoff_sleep;
> > > > + }
> > +
> > > > + /* Others poke directly at IOMUXC registers */
> > > > + switch (imx6_pcie->variant) {
> > > > + case IMX6SX:
> > > > + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
> > > > + IMX6SX_GPR12_PCIE_PM_TURN_OFF,
> > > > + IMX6SX_GPR12_PCIE_PM_TURN_OFF);
> > > > + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
> > > > + IMX6SX_GPR12_PCIE_PM_TURN_OFF, 0);
> > > > + break;
> > > > + default:
> > > > + dev_err(dev, "PME_Turn_Off not implemented\n");
> > > > + return;
> > > > + }
> >
> > > > /*
> > > > * Components with an upstream port must respond to
> > > > * PME_Turn_Off with PME_TO_Ack but we can't check.
> > > > *
> > > > * The standard recommends a 1-10ms timeout after which to
> > > > * proceed anyway as if acks were received.
> > > > */
> > +pm_turnoff_sleep:
> > > > usleep_range(1000, 10000);
> > }
> >
> > static void imx6_pcie_clk_disable(struct imx6_pcie *imx6_pcie)
> > {
> > > > clk_disable_unprepare(imx6_pcie->pcie);
> > > > clk_disable_unprepare(imx6_pcie->pcie_phy);
> > > > clk_disable_unprepare(imx6_pcie->pcie_bus);
> >
> > > > - if (imx6_pcie->variant == IMX7D) {
> > > > + switch (imx6_pcie->variant) {
> > > > + case IMX6SX:
> > > > + clk_disable_unprepare(imx6_pcie->pcie_inbound_axi);
> > > > + break;
> > > > + case IMX7D:
> > > > regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
> > > > IMX7D_GPR12_PCIE_PHY_REFCLK_SEL,
> > > > IMX7D_GPR12_PCIE_PHY_REFCLK_SEL);
> > > > + break;
> > > > + default:
> > > > + break;
> > > > }
> > }
> >
> > +static inline bool imx6_pcie_supports_suspend(struct imx6_pcie *imx6_pcie)
> > +{
> > > > + return (imx6_pcie->variant == IMX7D ||
> > > > + imx6_pcie->variant == IMX6SX);
> > +}
> > +
> > static int imx6_pcie_suspend_noirq(struct device *dev)
> > {
> > > > struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
> >
> > > > - if (imx6_pcie->variant != IMX7D)
> > > > + if (!imx6_pcie_supports_suspend(imx6_pcie))
> > > > return 0;
> >
> > > > imx6_pcie_pm_turnoff(imx6_pcie);
> > > > imx6_pcie_clk_disable(imx6_pcie);
> > > > imx6_pcie_ltssm_disable(dev);
> > @@ -817,11 +851,11 @@ static int imx6_pcie_resume_noirq(struct device *dev)
> > {
> > > > int ret;
> > > > struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
> > > > struct pcie_port *pp = &imx6_pcie->pci->pp;
> >
> > > > - if (imx6_pcie->variant != IMX7D)
> > > > + if (!imx6_pcie_supports_suspend(imx6_pcie))
> > > > return 0;
> >
> > > > imx6_pcie_assert_core_reset(imx6_pcie);
> > > > imx6_pcie_init_phy(imx6_pcie);
> > > > imx6_pcie_deassert_core_reset(imx6_pcie);
> > diff --git a/include/linux/mfd/syscon/imx6q-iomuxc-gpr.h b/include/linux/mfd/syscon/imx6q-iomuxc-gpr.h
> > index 6c1ad160ed87..c1b25f5e386d 100644
> > --- a/include/linux/mfd/syscon/imx6q-iomuxc-gpr.h
> > +++ b/include/linux/mfd/syscon/imx6q-iomuxc-gpr.h
> > @@ -438,10 +438,11 @@
> > > > #define IMX6SX_GPR5_DISP_MUX_DCIC1_LCDIF1 (0x0 << 1)
> > > > #define IMX6SX_GPR5_DISP_MUX_DCIC1_LVDS (0x1 << 1)
> > > > #define IMX6SX_GPR5_DISP_MUX_DCIC1_MASK (0x1 << 1)
> >
> > > > #define IMX6SX_GPR12_PCIE_TEST_POWERDOWN BIT(30)
> > > > +#define IMX6SX_GPR12_PCIE_PM_TURN_OFF BIT(16)
> > > > #define IMX6SX_GPR12_PCIE_RX_EQ_MASK (0x7 << 0)
> > > > #define IMX6SX_GPR12_PCIE_RX_EQ_2 (0x2 << 0)
> >
> > /* For imx6ul iomux gpr register field define */
> > > > #define IMX6UL_GPR1_ENET1_CLK_DIR (0x1 << 17)
> > --
> > 2.17.1
> >
On Wed, Nov 07, 2018 at 01:57:03PM +0000, Leonard Crestez wrote:
> Enable PCI suspend/resume support on imx6sx socs. This is similar to
> imx7d with a few differences:
>
> * The PM_Turn_Off bit is exposed through an IOMUX GPR, like all other
> pcie control bits on 6sx.
> * The pcie_inbound_axi clk needs to be turned off in suspend. On resume
> it is restored via resume -> deassert_core_reset -> enable_ref_clk.
>
> Most of the resume logic is shared with the initial reset after probe.
>
> Signed-off-by: Leonard Crestez <[email protected]>
>
> ---
> Changes since v1:
> * Use a switch statement in imx6_pcie_pm_turnoff. The DT-based turnoff
> path is still an if statement.
> * Did not split imx6_pcie_clk_disable or call it from other paths, this
> would bring complications and is somewhat unrelated.
> * See v1 comments: https://lore.kernel.org/patchwork/patch/996806/
>
> drivers/pci/controller/dwc/pci-imx6.c | 44 ++++++++++++++++++---
> include/linux/mfd/syscon/imx6q-iomuxc-gpr.h | 1 +
> 2 files changed, 40 insertions(+), 5 deletions(-)
Applied to pci/dwc for v4.21, thanks.
Lorenzo
> diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
> index 2cbef2d7c207..54625569d0bc 100644
> --- a/drivers/pci/controller/dwc/pci-imx6.c
> +++ b/drivers/pci/controller/dwc/pci-imx6.c
> @@ -771,41 +771,75 @@ static void imx6_pcie_ltssm_disable(struct device *dev)
> }
> }
>
> static void imx6_pcie_pm_turnoff(struct imx6_pcie *imx6_pcie)
> {
> - reset_control_assert(imx6_pcie->turnoff_reset);
> - reset_control_deassert(imx6_pcie->turnoff_reset);
> + struct device *dev = imx6_pcie->pci->dev;
> +
> + /* Some variants have a turnoff reset in DT */
> + if (imx6_pcie->turnoff_reset) {
> + reset_control_assert(imx6_pcie->turnoff_reset);
> + reset_control_deassert(imx6_pcie->turnoff_reset);
> + goto pm_turnoff_sleep;
> + }
> +
> + /* Others poke directly at IOMUXC registers */
> + switch (imx6_pcie->variant) {
> + case IMX6SX:
> + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
> + IMX6SX_GPR12_PCIE_PM_TURN_OFF,
> + IMX6SX_GPR12_PCIE_PM_TURN_OFF);
> + regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
> + IMX6SX_GPR12_PCIE_PM_TURN_OFF, 0);
> + break;
> + default:
> + dev_err(dev, "PME_Turn_Off not implemented\n");
> + return;
> + }
>
> /*
> * Components with an upstream port must respond to
> * PME_Turn_Off with PME_TO_Ack but we can't check.
> *
> * The standard recommends a 1-10ms timeout after which to
> * proceed anyway as if acks were received.
> */
> +pm_turnoff_sleep:
> usleep_range(1000, 10000);
> }
>
> static void imx6_pcie_clk_disable(struct imx6_pcie *imx6_pcie)
> {
> clk_disable_unprepare(imx6_pcie->pcie);
> clk_disable_unprepare(imx6_pcie->pcie_phy);
> clk_disable_unprepare(imx6_pcie->pcie_bus);
>
> - if (imx6_pcie->variant == IMX7D) {
> + switch (imx6_pcie->variant) {
> + case IMX6SX:
> + clk_disable_unprepare(imx6_pcie->pcie_inbound_axi);
> + break;
> + case IMX7D:
> regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12,
> IMX7D_GPR12_PCIE_PHY_REFCLK_SEL,
> IMX7D_GPR12_PCIE_PHY_REFCLK_SEL);
> + break;
> + default:
> + break;
> }
> }
>
> +static inline bool imx6_pcie_supports_suspend(struct imx6_pcie *imx6_pcie)
> +{
> + return (imx6_pcie->variant == IMX7D ||
> + imx6_pcie->variant == IMX6SX);
> +}
> +
> static int imx6_pcie_suspend_noirq(struct device *dev)
> {
> struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
>
> - if (imx6_pcie->variant != IMX7D)
> + if (!imx6_pcie_supports_suspend(imx6_pcie))
> return 0;
>
> imx6_pcie_pm_turnoff(imx6_pcie);
> imx6_pcie_clk_disable(imx6_pcie);
> imx6_pcie_ltssm_disable(dev);
> @@ -817,11 +851,11 @@ static int imx6_pcie_resume_noirq(struct device *dev)
> {
> int ret;
> struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
> struct pcie_port *pp = &imx6_pcie->pci->pp;
>
> - if (imx6_pcie->variant != IMX7D)
> + if (!imx6_pcie_supports_suspend(imx6_pcie))
> return 0;
>
> imx6_pcie_assert_core_reset(imx6_pcie);
> imx6_pcie_init_phy(imx6_pcie);
> imx6_pcie_deassert_core_reset(imx6_pcie);
> diff --git a/include/linux/mfd/syscon/imx6q-iomuxc-gpr.h b/include/linux/mfd/syscon/imx6q-iomuxc-gpr.h
> index 6c1ad160ed87..c1b25f5e386d 100644
> --- a/include/linux/mfd/syscon/imx6q-iomuxc-gpr.h
> +++ b/include/linux/mfd/syscon/imx6q-iomuxc-gpr.h
> @@ -438,10 +438,11 @@
> #define IMX6SX_GPR5_DISP_MUX_DCIC1_LCDIF1 (0x0 << 1)
> #define IMX6SX_GPR5_DISP_MUX_DCIC1_LVDS (0x1 << 1)
> #define IMX6SX_GPR5_DISP_MUX_DCIC1_MASK (0x1 << 1)
>
> #define IMX6SX_GPR12_PCIE_TEST_POWERDOWN BIT(30)
> +#define IMX6SX_GPR12_PCIE_PM_TURN_OFF BIT(16)
> #define IMX6SX_GPR12_PCIE_RX_EQ_MASK (0x7 << 0)
> #define IMX6SX_GPR12_PCIE_RX_EQ_2 (0x2 << 0)
>
> /* For imx6ul iomux gpr register field define */
> #define IMX6UL_GPR1_ENET1_CLK_DIR (0x1 << 17)
> --
> 2.17.1
>