Patchwork [RFC,2/2] PCI: exynos: Add PCIe support for Samsung GH7 SoC

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Submitter Jingoo Han
Date April 16, 2014, 4:43 a.m.
Message ID <000a01cf592e$67e592e0$37b0b8a0$%han@samsung.com>
Download mbox | patch
Permalink /patch/339428/
State Not Applicable
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Comments

Jingoo Han - April 16, 2014, 4:43 a.m.
Samsung GH7 has four PCIe controllers which can be used as root
complex for PCIe interface.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
---
 drivers/pci/host/Kconfig      |    2 +-
 drivers/pci/host/pci-exynos.c |  135 ++++++++++++++++++++++++++++++++++++++---
 2 files changed, 126 insertions(+), 11 deletions(-)
Arnd Bergmann - April 22, 2014, 2:11 p.m.
On Wednesday 16 April 2014, Jingoo Han wrote:
> Samsung GH7 has four PCIe controllers which can be used as root
> complex for PCIe interface.
> 
> Signed-off-by: Jingoo Han <jg1.han@samsung.com>
> ---
>  drivers/pci/host/Kconfig      |    2 +-
>  drivers/pci/host/pci-exynos.c |  135 ++++++++++++++++++++++++++++++++++++++---
>  2 files changed, 126 insertions(+), 11 deletions(-)

Can you explain how much the GH7 and Exynos front-ends actually have in
common? Would it make sense to have a separate driver for gh7?

Also, if gh7 is expected to run a full firmware, I think you should
do all the setup in the firmware before booting Linux, and just
do the required run-time operations in the driver itself.

	Arnd
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Kukjin Kim - April 23, 2014, 9:19 a.m.
Arnd Bergmann wrote:
> 
> On Wednesday 16 April 2014, Jingoo Han wrote:
> > Samsung GH7 has four PCIe controllers which can be used as root
> > complex for PCIe interface.
> >
> > Signed-off-by: Jingoo Han <jg1.han@samsung.com>
> > ---
> >  drivers/pci/host/Kconfig      |    2 +-
> >  drivers/pci/host/pci-exynos.c |  135
> ++++++++++++++++++++++++++++++++++++++---
> >  2 files changed, 126 insertions(+), 11 deletions(-)
> 
+ Byungho An, Ilho Lee

Hi Arnd,

> Can you explain how much the GH7 and Exynos front-ends actually have in
> common? Would it make sense to have a separate driver for gh7?
> 
Basically, ARMv8 based GH7 has same PCIe hardware IP with previous ARMv7
based exynos5440, several features in PCIe are different though. In other
words, basic functionalities for PCIe are same. So I think, would be nice if
we could use one PCIe device driver for both SoCs.

However, if we need to support the PCIe with each own device driver because
of difference of 32bit and 64bit, please kindly let us know. Honestly, I'm
not sure about that right now.

> Also, if gh7 is expected to run a full firmware, I think you should
> do all the setup in the firmware before booting Linux, and just
> do the required run-time operations in the driver itself.
> 
Well, we're expecting that all the setup should be done by the device driver
in kernel not firmware.

Thanks,
Kukjin

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Arnd Bergmann - April 23, 2014, 11:03 a.m.
On Wednesday 23 April 2014 18:19:30 Kukjin Kim wrote:
> 

> Basically, ARMv8 based GH7 has same PCIe hardware IP with previous ARMv7
> based exynos5440, several features in PCIe are different though. In other
> words, basic functionalities for PCIe are same. So I think, would be nice if
> we could use one PCIe device driver for both SoCs.

Ok, I see. I was just trying to get a feeling for how much is shared
or SoC specific between your variants. If they are different enough,
it may be easier to have two drivers.

> However, if we need to support the PCIe with each own device driver because
> of difference of 32bit and 64bit, please kindly let us know. Honestly, I'm
> not sure about that right now.

We are working already on ideas to minimize the differences between
arm32 and arm64 PCI support, it will just take more work.

> > Also, if gh7 is expected to run a full firmware, I think you should
> > do all the setup in the firmware before booting Linux, and just
> > do the required run-time operations in the driver itself.
> > 
> Well, we're expecting that all the setup should be done by the device driver
> in kernel not firmware.

Ok, just make sure this hardware never shows up in servers then.

Unfortunately we are in a tricky situation on arm64 because we have
to support both server-type SoCs and embedded-type SoCs. In an
embedded system, you can't trust the boot loader to do a proper
setup of all the hardware, so the kernel needs full control over
all the initialization. In a server, the initialization is the
responsibility of the firmware, and we don't want the kernel to
even know about those registers.

My hope is that all server chips use an SBSA compliant PCIe
implementation, but we already have X-Gene, which is doing server
workloads with a nonstandard PCIe, and it's possible that there
will also be server-like systems with a DesignWare PCIe block
instead of an SBSA compliant one. We can still support those, but
I don't want to see more than one implementation of dw-pcie
on servers. Just like we have the generic PCIe support that Will
is doing for virtual machines and SBSA compliant systems, we
would do one dw-pcie variant for all systems that come with a
host firmware and rely on it being set up already.

	Arnd
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Liviu Dudau - April 23, 2014, 1 p.m.
On Wed, Apr 23, 2014 at 10:19:30AM +0100, Kukjin Kim wrote:
> Arnd Bergmann wrote:
> > 
> > On Wednesday 16 April 2014, Jingoo Han wrote:
> > > Samsung GH7 has four PCIe controllers which can be used as root
> > > complex for PCIe interface.
> > >
> > > Signed-off-by: Jingoo Han <jg1.han@samsung.com>
> > > ---
> > >  drivers/pci/host/Kconfig      |    2 +-
> > >  drivers/pci/host/pci-exynos.c |  135
> > ++++++++++++++++++++++++++++++++++++++---
> > >  2 files changed, 126 insertions(+), 11 deletions(-)
> > 
> + Byungho An, Ilho Lee
> 
> Hi Arnd,
> 
> > Can you explain how much the GH7 and Exynos front-ends actually have in
> > common? Would it make sense to have a separate driver for gh7?
> > 
> Basically, ARMv8 based GH7 has same PCIe hardware IP with previous ARMv7
> based exynos5440, several features in PCIe are different though. In other
> words, basic functionalities for PCIe are same. So I think, would be nice if
> we could use one PCIe device driver for both SoCs.
> 
> However, if we need to support the PCIe with each own device driver because
> of difference of 32bit and 64bit, please kindly let us know. Honestly, I'm
> not sure about that right now.

Hi Kukjin,

I will let Arnd offer his view as a maintainer of DT enabled platforms for 
arch/arm, but in my understanding the goal is to convert individual host
bridge drivers to use my patch series directly, as they intentionally don't
depend on any arch specific code and then leave the existing bios32 code
for the non-DT platforms and the ones that do not see the need to convert
to the framework.

Rob Herring has posted an example on how he can add support for a host
bridge running under arm32 that uses my framework, so it is not an impossible
task and can be used as an example for future conversions.

Does that make sense?

Best regards,
Liviu

> 
> > Also, if gh7 is expected to run a full firmware, I think you should
> > do all the setup in the firmware before booting Linux, and just
> > do the required run-time operations in the driver itself.
> > 
> Well, we're expecting that all the setup should be done by the device driver
> in kernel not firmware.
> 
> Thanks,
> Kukjin
> 
>
Liviu Dudau - April 23, 2014, 2:23 p.m.
On Wed, Apr 23, 2014 at 12:03:47PM +0100, Arnd Bergmann wrote:
> On Wednesday 23 April 2014 18:19:30 Kukjin Kim wrote:
> > 
> 
> > Basically, ARMv8 based GH7 has same PCIe hardware IP with previous ARMv7
> > based exynos5440, several features in PCIe are different though. In other
> > words, basic functionalities for PCIe are same. So I think, would be nice if
> > we could use one PCIe device driver for both SoCs.
> 
> Ok, I see. I was just trying to get a feeling for how much is shared
> or SoC specific between your variants. If they are different enough,
> it may be easier to have two drivers.
> 
> > However, if we need to support the PCIe with each own device driver because
> > of difference of 32bit and 64bit, please kindly let us know. Honestly, I'm
> > not sure about that right now.
> 
> We are working already on ideas to minimize the differences between
> arm32 and arm64 PCI support, it will just take more work.
> 
> > > Also, if gh7 is expected to run a full firmware, I think you should
> > > do all the setup in the firmware before booting Linux, and just
> > > do the required run-time operations in the driver itself.
> > > 
> > Well, we're expecting that all the setup should be done by the device driver
> > in kernel not firmware.
> 
> Ok, just make sure this hardware never shows up in servers then.

Not necessarily, as long as the setup will always happen in the kernel?

> 
> Unfortunately we are in a tricky situation on arm64 because we have
> to support both server-type SoCs and embedded-type SoCs. In an
> embedded system, you can't trust the boot loader to do a proper
> setup of all the hardware, so the kernel needs full control over
> all the initialization. In a server, the initialization is the
> responsibility of the firmware, and we don't want the kernel to
> even know about those registers.
> 
> My hope is that all server chips use an SBSA compliant PCIe
> implementation, but we already have X-Gene, which is doing server
> workloads with a nonstandard PCIe, and it's possible that there
> will also be server-like systems with a DesignWare PCIe block
> instead of an SBSA compliant one. We can still support those, but
> I don't want to see more than one implementation of dw-pcie
> on servers. Just like we have the generic PCIe support that Will
> is doing for virtual machines and SBSA compliant systems, we
> would do one dw-pcie variant for all systems that come with a
> host firmware and rely on it being set up already.

There is nothing in the SBSA that mandates firmware setup. All it requires
is that hardware is setup in a way that is not specific to a board
or a particular OEM. Surely if the setup being done for GH7 is always
the same it should fit the bill?

Kind regards,
Liviu


> 
> 	Arnd
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> 
>
Arnd Bergmann - April 23, 2014, 4:20 p.m.
On Wednesday 23 April 2014 15:23:16 Liviu Dudau wrote:
> > Unfortunately we are in a tricky situation on arm64 because we have
> > to support both server-type SoCs and embedded-type SoCs. In an
> > embedded system, you can't trust the boot loader to do a proper
> > setup of all the hardware, so the kernel needs full control over
> > all the initialization. In a server, the initialization is the
> > responsibility of the firmware, and we don't want the kernel to
> > even know about those registers.
> > 
> > My hope is that all server chips use an SBSA compliant PCIe
> > implementation, but we already have X-Gene, which is doing server
> > workloads with a nonstandard PCIe, and it's possible that there
> > will also be server-like systems with a DesignWare PCIe block
> > instead of an SBSA compliant one. We can still support those, but
> > I don't want to see more than one implementation of dw-pcie
> > on servers. Just like we have the generic PCIe support that Will
> > is doing for virtual machines and SBSA compliant systems, we
> > would do one dw-pcie variant for all systems that come with a
> > host firmware and rely on it being set up already.
> 
> There is nothing in the SBSA that mandates firmware setup. All it requires
> is that hardware is setup in a way that is not specific to a board
> or a particular OEM. Surely if the setup being done for GH7 is always
> the same it should fit the bill?

GH7 is already not SBSA compliant because it uses a nonstandard config
space access method, and it uses its own MSI controller rather than GIC.
This means it violates at least two out of the four clauses in SBSA
describing PCIe.

Regardless of this, the level of detail describing config space and
MSI handling in SBSA can only make sense if the purpose is to handle
all compliant implementations without platform specific code. If you
require platform specific setup code in the OS, this underlying assumption
no longer holds true and there is no point in having a spec in the
first place.

I think we should treat DW-PCIe in the same way if anyone attempts
to use that in a server, e.g. in SBSA level 0. As you can see here,
even when reusing hardware between Exynos and GH7, you can't just
use the same init code, so it has to be in firmware to be any good.
On a real server platform, you can't require a kernel upgrade every
time a new SoC comes out, any basic functionality like PCI just has to
work with existing OS images.

	Arnd
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Kukjin Kim - April 24, 2014, 4:53 a.m.
Arnd Bergmann wrote:
> 
> On Wednesday 23 April 2014 15:23:16 Liviu Dudau wrote:
> > > Unfortunately we are in a tricky situation on arm64 because we have
> > > to support both server-type SoCs and embedded-type SoCs. In an
> > > embedded system, you can't trust the boot loader to do a proper
> > > setup of all the hardware, so the kernel needs full control over
> > > all the initialization. In a server, the initialization is the
> > > responsibility of the firmware, and we don't want the kernel to
> > > even know about those registers.

BTW, actually we can trust boot-loader to do required things in mobile also ;-)

> > >
> > > My hope is that all server chips use an SBSA compliant PCIe
> > > implementation, but we already have X-Gene, which is doing server
> > > workloads with a nonstandard PCIe, and it's possible that there
> > > will also be server-like systems with a DesignWare PCIe block
> > > instead of an SBSA compliant one. We can still support those, but
> > > I don't want to see more than one implementation of dw-pcie
> > > on servers. Just like we have the generic PCIe support that Will
> > > is doing for virtual machines and SBSA compliant systems, we
> > > would do one dw-pcie variant for all systems that come with a
> > > host firmware and rely on it being set up already.

OK and I think, just one device driver would be nice for whatever embedded or
server.

> >
> > There is nothing in the SBSA that mandates firmware setup. All it requires

Yeah, I couldn't look at that in the SBSA...

> > is that hardware is setup in a way that is not specific to a board
> > or a particular OEM. Surely if the setup being done for GH7 is always
> > the same it should fit the bill?
> 
But Arnd's comments are about firmware based on each SoC not board?...

> GH7 is already not SBSA compliant because it uses a nonstandard config
> space access method, and it uses its own MSI controller rather than GIC.
> This means it violates at least two out of the four clauses in SBSA
> describing PCIe.
> 
OK, I see. Honestly, we just focused on how to support PCI on both exynos5440
and GH7 SoCs.

> Regardless of this, the level of detail describing config space and
> MSI handling in SBSA can only make sense if the purpose is to handle
> all compliant implementations without platform specific code. If you
> require platform specific setup code in the OS, this underlying assumption
> no longer holds true and there is no point in having a spec in the
> first place.
> 
OK, your assumption makes sense to us.

> I think we should treat DW-PCIe in the same way if anyone attempts
> to use that in a server, e.g. in SBSA level 0. As you can see here,

Agreed. BTW, how about GICv2m for level 1? It can be supported with the same
way in one DW-PCIe driver?

> even when reusing hardware between Exynos and GH7, you can't just
> use the same init code, so it has to be in firmware to be any good.
> On a real server platform, you can't require a kernel upgrade every
> time a new SoC comes out, any basic functionality like PCI just has to
> work with existing OS images.
> 
OK, when Will's driver is ready, we will test it on GH7 with the setup for PCIe
included in firmware. Anyway I hope we can use the driver in 3.16 :-)

Thanks,
Kukjin

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Arnd Bergmann - April 24, 2014, 9:49 a.m.
On Thursday 24 April 2014 13:53:47 Kukjin Kim wrote:
> Arnd Bergmann wrote:
> > 
> > On Wednesday 23 April 2014 15:23:16 Liviu Dudau wrote:
> > > > Unfortunately we are in a tricky situation on arm64 because we have
> > > > to support both server-type SoCs and embedded-type SoCs. In an
> > > > embedded system, you can't trust the boot loader to do a proper
> > > > setup of all the hardware, so the kernel needs full control over
> > > > all the initialization. In a server, the initialization is the
> > > > responsibility of the firmware, and we don't want the kernel to
> > > > even know about those registers.
> 
> BTW, actually we can trust boot-loader to do required things in mobile also ;-)

Not really. Those boot loaders do the bare minimum to get one kernel
running. There is no testing done with distro kernels (usually because
they won't work anyway), and they wouldn't touch (or describe in DT) any
hardware that isn't actually used by the kernel that initially ships
with the device.

If we could trust the boot loader to do all the necessary setup,
we would get rid of a lot of kernel code.

> > > > My hope is that all server chips use an SBSA compliant PCIe
> > > > implementation, but we already have X-Gene, which is doing server
> > > > workloads with a nonstandard PCIe, and it's possible that there
> > > > will also be server-like systems with a DesignWare PCIe block
> > > > instead of an SBSA compliant one. We can still support those, but
> > > > I don't want to see more than one implementation of dw-pcie
> > > > on servers. Just like we have the generic PCIe support that Will
> > > > is doing for virtual machines and SBSA compliant systems, we
> > > > would do one dw-pcie variant for all systems that come with a
> > > > host firmware and rely on it being set up already.
> 
> OK and I think, just one device driver would be nice for whatever
> embedded or server.

The runtime parts (e.g. config space access) should definitely
be shared, and we should also share any peripheral drivers.

However, basic infrastructure like PCI on servers should just work
and you really shouldn't require any driver code for it. SBSA gets
this part right by defining the config space layout, so we can have
a very trivial PCI host driver for all SBSA systems, even if the
same hardware needs a SoC specific driver for embedded systems that
don't initialize the PCI host at boot time.

There is also nothing wrong with embedded systems doing it the same
way as servers and initializing everything before Linux starts. We
just need to be prepared to add fixups when someone gets it wrong.

> > I think we should treat DW-PCIe in the same way if anyone attempts
> > to use that in a server, e.g. in SBSA level 0. As you can see here,
> 
> Agreed. BTW, how about GICv2m for level 1? It can be supported with the same
> way in one DW-PCIe driver?

I don't think anybody has done a DT binding for GICv2m or submitted a
patch yet, but I'm pretty sure it can be done. We just need to come
up with a proper DT representation to pick which MSI controller is
used by default.

Hardware-wise you should be able to mix any combination of MSI controllers,
but I would suspect that if there is a GICv2m or higher, we would always
want to use that for performance reasons. The MSI controller in the
dw-pcie block just sends a normal interrupt to the GIC, which means you
lose all the benefits of using MSI.

> > even when reusing hardware between Exynos and GH7, you can't just
> > use the same init code, so it has to be in firmware to be any good.
> > On a real server platform, you can't require a kernel upgrade every
> > time a new SoC comes out, any basic functionality like PCI just has to
> > work with existing OS images.
> > 
> OK, when Will's driver is ready, we will test it on GH7 with the setup for PCIe
> included in firmware. Anyway I hope we can use the driver in 3.16 :-)

Ok, sounds good.

	Arnd
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Arnd Bergmann - April 24, 2014, 12:25 p.m.
On Wednesday 23 April 2014, Liviu Dudau wrote:
> On Wed, Apr 23, 2014 at 10:19:30AM +0100, Kukjin Kim wrote:
> > Arnd Bergmann wrote:
> > > 
> > > Can you explain how much the GH7 and Exynos front-ends actually have in
> > > common? Would it make sense to have a separate driver for gh7?
> > > 
> > Basically, ARMv8 based GH7 has same PCIe hardware IP with previous ARMv7
> > based exynos5440, several features in PCIe are different though. In other
> > words, basic functionalities for PCIe are same. So I think, would be nice if
> > we could use one PCIe device driver for both SoCs.
> > 
> > However, if we need to support the PCIe with each own device driver because
> > of difference of 32bit and 64bit, please kindly let us know. Honestly, I'm
> > not sure about that right now.
> 
> Hi Kukjin,
> 
> I will let Arnd offer his view as a maintainer of DT enabled platforms for 
> arch/arm, but in my understanding the goal is to convert individual host
> bridge drivers to use my patch series directly, as they intentionally don't
> depend on any arch specific code and then leave the existing bios32 code
> for the non-DT platforms and the ones that do not see the need to convert
> to the framework.
>
> Rob Herring has posted an example on how he can add support for a host
> bridge running under arm32 that uses my framework, so it is not an impossible
> task and can be used as an example for future conversions.

Yes, I agree that would be the best approach. I'm not sure if it
makes sense to convert the various dw-pcie front-ends separately
or if we have to do them all at once though. Doing them together
may require some more coordination.

Let's also make sure to keep Russell in the loop regarding arm32
PCI support. He probably has some ideas as well on how we should
proceed with the existing code.

	Arnd
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Patch

diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
index a6f67ec..3be047c 100644
--- a/drivers/pci/host/Kconfig
+++ b/drivers/pci/host/Kconfig
@@ -11,7 +11,7 @@  config PCIE_DW
 
 config PCI_EXYNOS
 	bool "Samsung Exynos PCIe controller"
-	depends on SOC_EXYNOS5440
+	depends on SOC_EXYNOS5440 || ARCH_GH7
 	select PCIEPORTBUS
 	select PCIE_DW
 
diff --git a/drivers/pci/host/pci-exynos.c b/drivers/pci/host/pci-exynos.c
index 3de6bfb..6e845ca 100644
--- a/drivers/pci/host/pci-exynos.c
+++ b/drivers/pci/host/pci-exynos.c
@@ -57,6 +57,8 @@  struct exynos_pcie {
 #define PCIE_NONSTICKY_RESET		0x024
 #define PCIE_APP_INIT_RESET		0x028
 #define PCIE_APP_LTSSM_ENABLE		0x02c
+#define PCIE_SYS_AUX_PWR_DET		0x038
+#define PCIE_SYS_AUX_PWR_ENABLE		(0x1 << 0)
 #define PCIE_ELBI_RDLH_LINKUP		0x064
 #define PCIE_ELBI_LTSSM_ENABLE		0x1
 #define PCIE_ELBI_SLV_AWMISC		0x11c
@@ -72,6 +74,23 @@  struct exynos_pcie {
 #define PCIE_PHY_TRSVREG_RESET		0x020
 #define PCIE_PHY_TRSV_RESET		0x024
 
+/* PCIe PHY glue registers */
+#define PCIE_PHY_GLUE_REG0		0x000
+#define PCIE_PHY_GLUE_GLOBAL_RESET	(0x1 << 0)
+#define PCIE_PHY_GLUE_COMMON_RESET	(0x1 << 1)
+#define PCIE_PHY_GLUE_MAC_RESET		(0x1 << 11)
+#define PCIE_PHY_GLUE_REG2		0x008
+#define PCIE_PHY_GLUE_CLK100M_DS_MAX	(0x7 << 0)
+#define PCIE_PHY_GLUE_CLK100M_RFCLK	(0x1 << 3)
+#define PCIE_PHY_GLUE_CLK100M_ENABLE	(0x1 << 4)
+#define PCIE_PHY_GLUE_PLL_BUF_ENABLE	(0x1 << 8)
+#define PCIE_PHY_GLUE_PLL_DIV_ENABLE	(0x1 << 9)
+#define PCIE_PHY_GLUE_REFCLK_IN(x)	(((x) & 0xf) << 10)
+#define PCIE_PHY_GLUE_REG3		0x00c
+#define PCIE_PHY_GLUE_REF_RATE_100MHZ	(0x2 << 0)
+#define PCIE_PHY_GLUE_REG4		0x010
+#define PCIE_PHY_GLUE_MODE_PCIE		(0x0 << 0)
+
 /* PCIe PHY registers */
 #define PCIE_PHY_IMPEDANCE		0x004
 #define PCIE_PHY_PLL_DIV_0		0x008
@@ -164,11 +183,45 @@  static void exynos_pcie_sideband_dbi_r_mode(struct pcie_port *pp, bool on)
 	}
 }
 
+static void exynos_pcie_set_phy_mode(struct pcie_port *pp)
+{
+	u32 val;
+	struct exynos_pcie *exynos_pcie = to_exynos_pcie(pp);
+
+	if (!of_device_is_compatible(pp->dev->of_node, "samsung,gh7-pcie"))
+		return;
+
+	/* configure phy reference clock setting */
+	val = exynos_blk_readl(exynos_pcie, PCIE_PHY_GLUE_REG2);
+	val |= PCIE_PHY_GLUE_CLK100M_ENABLE | PCIE_PHY_GLUE_CLK100M_RFCLK |
+		PCIE_PHY_GLUE_CLK100M_DS_MAX;
+	exynos_blk_writel(exynos_pcie, val, PCIE_PHY_GLUE_REG2);
+
+	val = exynos_blk_readl(exynos_pcie, PCIE_PHY_GLUE_REG2);
+	val |= PCIE_PHY_GLUE_PLL_DIV_ENABLE | PCIE_PHY_GLUE_PLL_BUF_ENABLE;
+	exynos_blk_writel(exynos_pcie, val, PCIE_PHY_GLUE_REG2);
+
+	val = exynos_blk_readl(exynos_pcie, PCIE_PHY_GLUE_REG2);
+	val |= PCIE_PHY_GLUE_REFCLK_IN(6);
+	exynos_blk_writel(exynos_pcie, val, PCIE_PHY_GLUE_REG2);
+
+	/* set phy reference clock  */
+	exynos_blk_writel(exynos_pcie, PCIE_PHY_GLUE_REF_RATE_100MHZ,
+			  PCIE_PHY_GLUE_REG3);
+
+	/* set phy mode to pcie mode */
+	exynos_blk_writel(exynos_pcie, PCIE_PHY_GLUE_MODE_PCIE,
+			  PCIE_PHY_GLUE_REG4);
+}
+
 static void exynos_pcie_assert_core_reset(struct pcie_port *pp)
 {
 	u32 val;
 	struct exynos_pcie *exynos_pcie = to_exynos_pcie(pp);
 
+	if (of_device_is_compatible(pp->dev->of_node, "samsung,gh7-pcie"))
+		return;
+
 	val = exynos_elb_readl(exynos_pcie, PCIE_CORE_RESET);
 	val &= ~PCIE_CORE_RESET_ENABLE;
 	exynos_elb_writel(exynos_pcie, val, PCIE_CORE_RESET);
@@ -190,27 +243,48 @@  static void exynos_pcie_deassert_core_reset(struct pcie_port *pp)
 	exynos_elb_writel(exynos_pcie, 1, PCIE_NONSTICKY_RESET);
 	exynos_elb_writel(exynos_pcie, 1, PCIE_APP_INIT_RESET);
 	exynos_elb_writel(exynos_pcie, 0, PCIE_APP_INIT_RESET);
-	exynos_blk_writel(exynos_pcie, 1, PCIE_PHY_MAC_RESET);
+
+	if (of_device_is_compatible(pp->dev->of_node, "samsung,gh7-pcie")) {
+		val = exynos_blk_readl(exynos_pcie, PCIE_PHY_GLUE_REG0);
+		val |= PCIE_PHY_GLUE_MAC_RESET;
+		exynos_blk_writel(exynos_pcie, val, PCIE_PHY_GLUE_REG0);
+	} else {
+		exynos_blk_writel(exynos_pcie, 1, PCIE_PHY_MAC_RESET);
+	}
 }
 
 static void exynos_pcie_assert_phy_reset(struct pcie_port *pp)
 {
 	struct exynos_pcie *exynos_pcie = to_exynos_pcie(pp);
 
+	if (of_device_is_compatible(pp->dev->of_node, "samsung,gh7-pcie"))
+		return;
+
 	exynos_blk_writel(exynos_pcie, 0, PCIE_PHY_MAC_RESET);
 	exynos_blk_writel(exynos_pcie, 1, PCIE_PHY_GLOBAL_RESET);
 }
 
 static void exynos_pcie_deassert_phy_reset(struct pcie_port *pp)
 {
+	u32 val;
 	struct exynos_pcie *exynos_pcie = to_exynos_pcie(pp);
 
-	exynos_blk_writel(exynos_pcie, 0, PCIE_PHY_GLOBAL_RESET);
-	exynos_elb_writel(exynos_pcie, 1, PCIE_PWR_RESET);
-	exynos_blk_writel(exynos_pcie, 0, PCIE_PHY_COMMON_RESET);
-	exynos_blk_writel(exynos_pcie, 0, PCIE_PHY_CMN_REG);
-	exynos_blk_writel(exynos_pcie, 0, PCIE_PHY_TRSVREG_RESET);
-	exynos_blk_writel(exynos_pcie, 0, PCIE_PHY_TRSV_RESET);
+	if (of_device_is_compatible(pp->dev->of_node, "samsung,gh7-pcie")) {
+		val = exynos_blk_readl(exynos_pcie, PCIE_PHY_GLUE_REG0);
+		val |= PCIE_PHY_GLUE_GLOBAL_RESET;
+		exynos_blk_writel(exynos_pcie, val, PCIE_PHY_GLUE_REG0);
+		exynos_elb_writel(exynos_pcie, 1, PCIE_PWR_RESET);
+		val = exynos_blk_readl(exynos_pcie, PCIE_PHY_GLUE_REG0);
+		val |= PCIE_PHY_GLUE_COMMON_RESET;
+		exynos_blk_writel(exynos_pcie, val, PCIE_PHY_GLUE_REG0);
+	} else {
+		exynos_blk_writel(exynos_pcie, 0, PCIE_PHY_GLOBAL_RESET);
+		exynos_elb_writel(exynos_pcie, 1, PCIE_PWR_RESET);
+		exynos_blk_writel(exynos_pcie, 0, PCIE_PHY_COMMON_RESET);
+		exynos_blk_writel(exynos_pcie, 0, PCIE_PHY_CMN_REG);
+		exynos_blk_writel(exynos_pcie, 0, PCIE_PHY_TRSVREG_RESET);
+		exynos_blk_writel(exynos_pcie, 0, PCIE_PHY_TRSV_RESET);
+	}
 }
 
 static void exynos_pcie_power_on_phy(struct pcie_port *pp)
@@ -269,6 +343,9 @@  static void exynos_pcie_init_phy(struct pcie_port *pp)
 {
 	struct exynos_pcie *exynos_pcie = to_exynos_pcie(pp);
 
+	if (of_device_is_compatible(pp->dev->of_node, "samsung,gh7-pcie"))
+		return;
+
 	/* DCC feedback control off */
 	exynos_phy_writel(exynos_pcie, 0x29, PCIE_PHY_DCC_FEEDBACK);
 
@@ -305,6 +382,26 @@  static void exynos_pcie_init_phy(struct pcie_port *pp)
 	exynos_phy_writel(exynos_pcie, 0xa0, PCIE_PHY_TRSV3_LVCC);
 }
 
+static void exynos_pcie_pulse_common_reset(struct pcie_port *pp)
+{
+	u32 val;
+	struct exynos_pcie *exynos_pcie = to_exynos_pcie(pp);
+
+	if (of_device_is_compatible(pp->dev->of_node, "samsung,gh7-pcie")) {
+		val = exynos_blk_readl(exynos_pcie, PCIE_PHY_GLUE_REG0);
+		val &= ~PCIE_PHY_GLUE_COMMON_RESET;
+		exynos_blk_writel(exynos_pcie, val, PCIE_PHY_GLUE_REG0);
+		udelay(500);
+		val = exynos_blk_readl(exynos_pcie, PCIE_PHY_GLUE_REG0);
+		val |= PCIE_PHY_GLUE_COMMON_RESET;
+		exynos_blk_writel(exynos_pcie, val, PCIE_PHY_GLUE_REG0);
+	} else {
+		exynos_blk_writel(exynos_pcie, 1, PCIE_PHY_COMMON_RESET);
+		udelay(500);
+		exynos_blk_writel(exynos_pcie, 0, PCIE_PHY_COMMON_RESET);
+	}
+}
+
 static void exynos_pcie_assert_reset(struct pcie_port *pp)
 {
 	struct exynos_pcie *exynos_pcie = to_exynos_pcie(pp);
@@ -326,6 +423,9 @@  static int exynos_pcie_establish_link(struct pcie_port *pp)
 		return 0;
 	}
 
+	/* set phy mode */
+	exynos_pcie_set_phy_mode(pp);
+
 	/* assert reset signals */
 	exynos_pcie_assert_core_reset(pp);
 	exynos_pcie_assert_phy_reset(pp);
@@ -340,9 +440,7 @@  static int exynos_pcie_establish_link(struct pcie_port *pp)
 	exynos_pcie_init_phy(pp);
 
 	/* pulse for common reset */
-	exynos_blk_writel(exynos_pcie, 1, PCIE_PHY_COMMON_RESET);
-	udelay(500);
-	exynos_blk_writel(exynos_pcie, 0, PCIE_PHY_COMMON_RESET);
+	exynos_pcie_pulse_common_reset(pp);
 
 	/* de-assert core reset */
 	exynos_pcie_deassert_core_reset(pp);
@@ -357,6 +455,12 @@  static int exynos_pcie_establish_link(struct pcie_port *pp)
 	exynos_elb_writel(exynos_pcie, PCIE_ELBI_LTSSM_ENABLE,
 			  PCIE_APP_LTSSM_ENABLE);
 
+	if (of_device_is_compatible(pp->dev->of_node, "samsung,gh7-pcie")) {
+		/* supply auxiliary power */
+		exynos_elb_writel(exynos_pcie, PCIE_SYS_AUX_PWR_ENABLE,
+				  PCIE_SYS_AUX_PWR_DET);
+	}
+
 	/* check if the link is up or not */
 	while (!dw_pcie_link_up(pp)) {
 		mdelay(100);
@@ -564,6 +668,7 @@  static int __init exynos_pcie_probe(struct platform_device *pdev)
 	struct resource *elbi_base;
 	struct resource *phy_base;
 	struct resource *block_base;
+	 struct resource *dbi_base;
 	int ret;
 
 	exynos_pcie = devm_kzalloc(&pdev->dev, sizeof(*exynos_pcie),
@@ -619,6 +724,15 @@  static int __init exynos_pcie_probe(struct platform_device *pdev)
 		goto fail_bus_clk;
 	}
 
+	if (of_device_is_compatible(pdev->dev.of_node, "samsung,gh7-pcie")) {
+		dbi_base = platform_get_resource(pdev, IORESOURCE_MEM, 3);
+		pp->dbi_base = devm_ioremap_resource(&pdev->dev, dbi_base);
+		if (IS_ERR(pp->dbi_base)) {
+			ret = PTR_ERR(pp->dbi_base);
+			goto fail_bus_clk;
+		}
+	}
+
 	ret = add_pcie_port(pp, pdev);
 	if (ret < 0)
 		goto fail_bus_clk;
@@ -645,6 +759,7 @@  static int __exit exynos_pcie_remove(struct platform_device *pdev)
 
 static const struct of_device_id exynos_pcie_of_match[] = {
 	{ .compatible = "samsung,exynos5440-pcie", },
+	{ .compatible = "samsung,gh7-pcie", },
 	{},
 };
 MODULE_DEVICE_TABLE(of, exynos_pcie_of_match);