diff mbox

[v9,3/6] pci:host: Add Altera PCIe host controller driver

Message ID 1444790492-4051-4-git-send-email-lftan@altera.com (mailing list archive)
State New, archived
Headers show

Commit Message

Ley Foon Tan Oct. 14, 2015, 2:41 a.m. UTC
This patch adds the Altera PCIe host controller driver.

Signed-off-by: Ley Foon Tan <lftan@altera.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/pci/host/Kconfig       |   7 +
 drivers/pci/host/Makefile      |   1 +
 drivers/pci/host/pcie-altera.c | 592 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 600 insertions(+)
 create mode 100644 drivers/pci/host/pcie-altera.c

Comments

Arnd Bergmann Oct. 14, 2015, 8:20 a.m. UTC | #1
On Wednesday 14 October 2015 10:41:29 Ley Foon Tan wrote:
> +static int altera_pcie_remove(struct platform_device *pdev)
> +{
> +	struct altera_pcie *pcie = platform_get_drvdata(pdev);
> +
> +	altera_pcie_free_irq_domain(pcie);
> +	platform_set_drvdata(pdev, NULL);
> +	return 0;
> +}

I just noticed this. Does it actually work to unload the module
and tear down all the pci_dev structures in a safe way?

	Arnd
Ley Foon Tan Oct. 14, 2015, 8:32 a.m. UTC | #2
On Wed, Oct 14, 2015 at 4:20 PM, Arnd Bergmann <arnd@arndb.de> wrote:
> On Wednesday 14 October 2015 10:41:29 Ley Foon Tan wrote:
>> +static int altera_pcie_remove(struct platform_device *pdev)
>> +{
>> +     struct altera_pcie *pcie = platform_get_drvdata(pdev);
>> +
>> +     altera_pcie_free_irq_domain(pcie);
>> +     platform_set_drvdata(pdev, NULL);
>> +     return 0;
>> +}
>
> I just noticed this. Does it actually work to unload the module
> and tear down all the pci_dev structures in a safe way?
Good catch. It only can be compiled as builtin-moduley now, so we can
remove this _remove callback function.
Thanks.

Regards
Ley Foon
Arnd Bergmann Oct. 14, 2015, 9:09 a.m. UTC | #3
On Wednesday 14 October 2015 16:32:25 Ley Foon Tan wrote:
> On Wed, Oct 14, 2015 at 4:20 PM, Arnd Bergmann <arnd@arndb.de> wrote:
> > On Wednesday 14 October 2015 10:41:29 Ley Foon Tan wrote:
> >> +static int altera_pcie_remove(struct platform_device *pdev)
> >> +{
> >> +     struct altera_pcie *pcie = platform_get_drvdata(pdev);
> >> +
> >> +     altera_pcie_free_irq_domain(pcie);
> >> +     platform_set_drvdata(pdev, NULL);
> >> +     return 0;
> >> +}
> >
> > I just noticed this. Does it actually work to unload the module
> > and tear down all the pci_dev structures in a safe way?
> Good catch. It only can be compiled as builtin-moduley now, so we can
> remove this _remove callback function.

I think we should change both: make it possible to load the
driver dynamically, and remove the altera_pcie_remove function.

You can prevent the module from being unloaded if you also remove
the module_platform_driver() directive and add a module_init()
without a matching module_exit().

Please also add a '.suppress_bind_attrs = true,' flag in the driver
struct to prevent manual unbinding.

	Arnd
Ley Foon Tan Oct. 14, 2015, 9:28 a.m. UTC | #4
On Wed, Oct 14, 2015 at 5:09 PM, Arnd Bergmann <arnd@arndb.de> wrote:
> On Wednesday 14 October 2015 16:32:25 Ley Foon Tan wrote:
>> On Wed, Oct 14, 2015 at 4:20 PM, Arnd Bergmann <arnd@arndb.de> wrote:
>> > On Wednesday 14 October 2015 10:41:29 Ley Foon Tan wrote:
>> >> +static int altera_pcie_remove(struct platform_device *pdev)
>> >> +{
>> >> +     struct altera_pcie *pcie = platform_get_drvdata(pdev);
>> >> +
>> >> +     altera_pcie_free_irq_domain(pcie);
>> >> +     platform_set_drvdata(pdev, NULL);
>> >> +     return 0;
>> >> +}
>> >
>> > I just noticed this. Does it actually work to unload the module
>> > and tear down all the pci_dev structures in a safe way?
>> Good catch. It only can be compiled as builtin-moduley now, so we can
>> remove this _remove callback function.
>
> I think we should change both: make it possible to load the
> driver dynamically, and remove the altera_pcie_remove function.
This driver depends on the pci fixups to work correctly. But, fixups
callback functions in this driver are not being call if the driver is
loadable module.
The linker script keeps all pci fixup callbacks in pci fixup regions
during kernel compile time. So, it needs to be builtin module. Do you
know any way we can update those fixup regions?

>
> You can prevent the module from being unloaded if you also remove
> the module_platform_driver() directive and add a module_init()
> without a matching module_exit().
>
> Please also add a '.suppress_bind_attrs = true,' flag in the driver
> struct to prevent manual unbinding.
I think we don't need these if it only can work as builtin module.

Thanks for reviewing.

Regards
Ley Foon
Arnd Bergmann Oct. 14, 2015, 9:36 a.m. UTC | #5
On Wednesday 14 October 2015 17:28:45 Ley Foon Tan wrote:
> On Wed, Oct 14, 2015 at 5:09 PM, Arnd Bergmann <arnd@arndb.de> wrote:
> > On Wednesday 14 October 2015 16:32:25 Ley Foon Tan wrote:
> >> On Wed, Oct 14, 2015 at 4:20 PM, Arnd Bergmann <arnd@arndb.de> wrote:
> >> > On Wednesday 14 October 2015 10:41:29 Ley Foon Tan wrote:
> >> >> +static int altera_pcie_remove(struct platform_device *pdev)
> >> >> +{
> >> >> +     struct altera_pcie *pcie = platform_get_drvdata(pdev);
> >> >> +
> >> >> +     altera_pcie_free_irq_domain(pcie);
> >> >> +     platform_set_drvdata(pdev, NULL);
> >> >> +     return 0;
> >> >> +}
> >> >
> >> > I just noticed this. Does it actually work to unload the module
> >> > and tear down all the pci_dev structures in a safe way?
> >> Good catch. It only can be compiled as builtin-moduley now, so we can
> >> remove this _remove callback function.
> >
> > I think we should change both: make it possible to load the
> > driver dynamically, and remove the altera_pcie_remove function.
> This driver depends on the pci fixups to work correctly. But, fixups
> callback functions in this driver are not being call if the driver is
> loadable module.

Ah, I see. We should find a better way to deal with this, as we
are getting an increasing number of host driver specific fixups.

Bjorn, do you have any idea here?

Could we perhaps have a helper function that lets us register
fixups dynamically?

> The linker script keeps all pci fixup callbacks in pci fixup regions
> during kernel compile time. So, it needs to be builtin module. Do you
> know any way we can update those fixup regions?

The only method I'm aware of at the moment is move the fixups to
drivers/pci/quirks.c and enclose them in an #ifdef if you want them
to not appear in kernels that don't support your SoC.

> > You can prevent the module from being unloaded if you also remove
> > the module_platform_driver() directive and add a module_init()
> > without a matching module_exit().
> >
> > Please also add a '.suppress_bind_attrs = true,' flag in the driver
> > struct to prevent manual unbinding.
> I think we don't need these if it only can work as builtin module.

No, this is orthogonal, you need it either way, as built-in drivers
can still be unbound by writing to sysfs. Try writing the device name
to /sys/bus/platform/drivers/altera-pcie/unbind and watch it blow up ;-)

	Arnd
Ley Foon Tan Oct. 14, 2015, 10:01 a.m. UTC | #6
On Wed, Oct 14, 2015 at 5:36 PM, Arnd Bergmann <arnd@arndb.de> wrote:
> On Wednesday 14 October 2015 17:28:45 Ley Foon Tan wrote:
>> On Wed, Oct 14, 2015 at 5:09 PM, Arnd Bergmann <arnd@arndb.de> wrote:
>> > On Wednesday 14 October 2015 16:32:25 Ley Foon Tan wrote:
>> >> On Wed, Oct 14, 2015 at 4:20 PM, Arnd Bergmann <arnd@arndb.de> wrote:
>> >> > On Wednesday 14 October 2015 10:41:29 Ley Foon Tan wrote:
>> >> >> +static int altera_pcie_remove(struct platform_device *pdev)
>> >> >> +{
>> >> >> +     struct altera_pcie *pcie = platform_get_drvdata(pdev);
>> >> >> +
>> >> >> +     altera_pcie_free_irq_domain(pcie);
>> >> >> +     platform_set_drvdata(pdev, NULL);
>> >> >> +     return 0;
>> >> >> +}
>> >> >
>> >> > I just noticed this. Does it actually work to unload the module
>> >> > and tear down all the pci_dev structures in a safe way?
>> >> Good catch. It only can be compiled as builtin-moduley now, so we can
>> >> remove this _remove callback function.
>> >
>> > I think we should change both: make it possible to load the
>> > driver dynamically, and remove the altera_pcie_remove function.
>> This driver depends on the pci fixups to work correctly. But, fixups
>> callback functions in this driver are not being call if the driver is
>> loadable module.
>
> Ah, I see. We should find a better way to deal with this, as we
> are getting an increasing number of host driver specific fixups.
>
> Bjorn, do you have any idea here?
>
> Could we perhaps have a helper function that lets us register
> fixups dynamically?
>
>> The linker script keeps all pci fixup callbacks in pci fixup regions
>> during kernel compile time. So, it needs to be builtin module. Do you
>> know any way we can update those fixup regions?
>
> The only method I'm aware of at the moment is move the fixups to
> drivers/pci/quirks.c and enclose them in an #ifdef if you want them
> to not appear in kernels that don't support your SoC.
By looking at the drivers/pci/quirks.c, it looks like it is mainly for
the pci endpoint devices.
Fixups for host controller are in the driver itself.

>
>> > You can prevent the module from being unloaded if you also remove
>> > the module_platform_driver() directive and add a module_init()
>> > without a matching module_exit().
>> >
>> > Please also add a '.suppress_bind_attrs = true,' flag in the driver
>> > struct to prevent manual unbinding.
>> I think we don't need these if it only can work as builtin module.
>
> No, this is orthogonal, you need it either way, as built-in drivers
> can still be unbound by writing to sysfs. Try writing the device name
> to /sys/bus/platform/drivers/altera-pcie/unbind and watch it blow up ;-)
Oh I see. Will update with your suggestion.

Thanks.

Regards
Ley Foon
Arnd Bergmann Oct. 14, 2015, 1:32 p.m. UTC | #7
On Wednesday 14 October 2015 18:01:46 Ley Foon Tan wrote:
> On Wed, Oct 14, 2015 at 5:36 PM, Arnd Bergmann <arnd@arndb.de> wrote:
> > On Wednesday 14 October 2015 17:28:45 Ley Foon Tan wrote:
> >> On Wed, Oct 14, 2015 at 5:09 PM, Arnd Bergmann <arnd@arndb.de> wrote:
> >
> > Could we perhaps have a helper function that lets us register
> > fixups dynamically?
> >
> >> The linker script keeps all pci fixup callbacks in pci fixup regions
> >> during kernel compile time. So, it needs to be builtin module. Do you
> >> know any way we can update those fixup regions?
> >
> > The only method I'm aware of at the moment is move the fixups to
> > drivers/pci/quirks.c and enclose them in an #ifdef if you want them
> > to not appear in kernels that don't support your SoC.
> By looking at the drivers/pci/quirks.c, it looks like it is mainly for
> the pci endpoint devices.
> Fixups for host controller are in the driver itself.
> 

But if it's for the host itself, there are usually other ways to
do this without needing a fixup: you already have the device structure
present in the driver, so you should just be able to modify it there.


I'm looking at the code in your fixups now:

+static void altera_pcie_retrain(struct pci_dev *dev)
+{
+       u16 linkcap, linkstat;
+
+       /*
+        * Set the retrain bit if the PCIe rootport support > 2.5GB/s, but
+        * current speed is 2.5 GB/s.
+        */
+       pcie_capability_read_word(dev, PCI_EXP_LNKCAP, &linkcap);
+
+       if ((linkcap & PCI_EXP_LNKCAP_SLS) <= PCI_EXP_LNKCAP_SLS_2_5GB)
+               return;
+
+       pcie_capability_read_word(dev, PCI_EXP_LNKSTA, &linkstat);
+       if ((linkstat & PCI_EXP_LNKSTA_CLS) == PCI_EXP_LNKSTA_CLS_2_5GB)
+               pcie_capability_set_word(dev, PCI_EXP_LNKCTL,
+                                        PCI_EXP_LNKCTL_RL);
+}
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_ALTERA, PCI_ANY_ID, altera_pcie_retrain);

This looks related to the code in pci_set_bus_speed(). What is
missing from that code?

+static void altera_pcie_fixup_res(struct pci_dev *dev)
+{
+       /*
+        * Prevent enumeration of root port.
+        */
+       if (!dev->bus->parent && dev->devfn == 0) {
+               int i;
+
+               for (i = 0; i < PCI_NUM_RESOURCES; i++) {
+                       dev->resource[i].start = 0;
+                       dev->resource[i].end   = 0;
+                       dev->resource[i].flags   = 0;
+               }
+       }
+}
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ALTERA, PCI_ANY_ID,
+                        altera_pcie_fixup_res);

This seems really odd, too. Why is this needed?
I think I've seen similar code in other host drivers, so
it might be time to teach the PCI core about this kind of
device.

	Arnd
Ley Foon Tan Oct. 16, 2015, 8:48 a.m. UTC | #8
On Wed, Oct 14, 2015 at 9:32 PM, Arnd Bergmann <arnd@arndb.de> wrote:
> On Wednesday 14 October 2015 18:01:46 Ley Foon Tan wrote:
>> On Wed, Oct 14, 2015 at 5:36 PM, Arnd Bergmann <arnd@arndb.de> wrote:
>> > On Wednesday 14 October 2015 17:28:45 Ley Foon Tan wrote:
>> >> On Wed, Oct 14, 2015 at 5:09 PM, Arnd Bergmann <arnd@arndb.de> wrote:
>> >
>> > Could we perhaps have a helper function that lets us register
>> > fixups dynamically?
>> >
>> >> The linker script keeps all pci fixup callbacks in pci fixup regions
>> >> during kernel compile time. So, it needs to be builtin module. Do you
>> >> know any way we can update those fixup regions?
>> >
>> > The only method I'm aware of at the moment is move the fixups to
>> > drivers/pci/quirks.c and enclose them in an #ifdef if you want them
>> > to not appear in kernels that don't support your SoC.
>> By looking at the drivers/pci/quirks.c, it looks like it is mainly for
>> the pci endpoint devices.
>> Fixups for host controller are in the driver itself.
>>
>
> But if it's for the host itself, there are usually other ways to
> do this without needing a fixup: you already have the device structure
> present in the driver, so you should just be able to modify it there.
Thanks for your suggestion. You are right, I have tested this can work as well.
So, I can remove those 2 PCI_FIXUP* in the driver.
>
>
> I'm looking at the code in your fixups now:
>
> +static void altera_pcie_retrain(struct pci_dev *dev)
> +{
> +       u16 linkcap, linkstat;
> +
> +       /*
> +        * Set the retrain bit if the PCIe rootport support > 2.5GB/s, but
> +        * current speed is 2.5 GB/s.
> +        */
> +       pcie_capability_read_word(dev, PCI_EXP_LNKCAP, &linkcap);
> +
> +       if ((linkcap & PCI_EXP_LNKCAP_SLS) <= PCI_EXP_LNKCAP_SLS_2_5GB)
> +               return;
> +
> +       pcie_capability_read_word(dev, PCI_EXP_LNKSTA, &linkstat);
> +       if ((linkstat & PCI_EXP_LNKSTA_CLS) == PCI_EXP_LNKSTA_CLS_2_5GB)
> +               pcie_capability_set_word(dev, PCI_EXP_LNKCTL,
> +                                        PCI_EXP_LNKCTL_RL);
> +}
> +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_ALTERA, PCI_ANY_ID, altera_pcie_retrain);
>
> This looks related to the code in pci_set_bus_speed(). What is
> missing from that code?
This fixup is different from pci_set_bus_speed(). This fixup is to set
the retrain bit in the LNKCTL register if the host can support higher
speed than current speed, this is required by our hardware. But,
pci_set_bus_speed() is just read the LNKCAP and LNKSTA registers and
store in data structure.

>
> +static void altera_pcie_fixup_res(struct pci_dev *dev)
> +{
> +       /*
> +        * Prevent enumeration of root port.
> +        */
> +       if (!dev->bus->parent && dev->devfn == 0) {
> +               int i;
> +
> +               for (i = 0; i < PCI_NUM_RESOURCES; i++) {
> +                       dev->resource[i].start = 0;
> +                       dev->resource[i].end   = 0;
> +                       dev->resource[i].flags   = 0;
> +               }
> +       }
> +}
> +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ALTERA, PCI_ANY_ID,
> +                        altera_pcie_fixup_res);
>
> This seems really odd, too. Why is this needed?
> I think I've seen similar code in other host drivers, so
> it might be time to teach the PCI core about this kind of
> device.
Yes, some host drivers have similar code as well. Some host controller
have the BAR configuration enabled, but it doesn't fit to kernel
resources. Example the BAR is 64-bit, but the processor is 32-bit. It
will fail at the host driver probing stage.

pci 0000:00:00.0: BAR 0: [mem 0x00000000-0xffffffff 64bit pref] has
bogus alignment

Regards
Ley Foon
diff mbox

Patch

diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
index d5e58ba..f956206 100644
--- a/drivers/pci/host/Kconfig
+++ b/drivers/pci/host/Kconfig
@@ -145,4 +145,11 @@  config PCIE_IPROC_BCMA
 	  Say Y here if you want to use the Broadcom iProc PCIe controller
 	  through the BCMA bus interface
 
+config PCIE_ALTERA
+	bool "Altera PCIe controller"
+	select PCI_DOMAINS
+	help
+        Say Y here if you want to enable PCIe controller support on Altera
+        FPGA.
+
 endmenu
diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile
index 140d66f..6954f76 100644
--- a/drivers/pci/host/Makefile
+++ b/drivers/pci/host/Makefile
@@ -17,3 +17,4 @@  obj-$(CONFIG_PCI_VERSATILE) += pci-versatile.o
 obj-$(CONFIG_PCIE_IPROC) += pcie-iproc.o
 obj-$(CONFIG_PCIE_IPROC_PLATFORM) += pcie-iproc-platform.o
 obj-$(CONFIG_PCIE_IPROC_BCMA) += pcie-iproc-bcma.o
+obj-$(CONFIG_PCIE_ALTERA) += pcie-altera.o
diff --git a/drivers/pci/host/pcie-altera.c b/drivers/pci/host/pcie-altera.c
new file mode 100644
index 0000000..e714e95
--- /dev/null
+++ b/drivers/pci/host/pcie-altera.c
@@ -0,0 +1,592 @@ 
+/*
+ * Copyright Altera Corporation (C) 2013-2015. All rights reserved
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_pci.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#define A2P_ADDR_MAP_LO0		0x1000
+#define A2P_ADDR_MAP_HI0		0x1004
+#define RP_TX_REG0			0x2000
+#define RP_TX_REG1			0x2004
+#define RP_TX_CNTRL			0x2008
+#define RP_TX_EOP			0x2
+#define RP_TX_SOP			0x1
+#define RP_RXCPL_STATUS		0x2010
+#define RP_RXCPL_EOP			0x2
+#define RP_RXCPL_SOP			0x1
+#define RP_RXCPL_REG0			0x2014
+#define RP_RXCPL_REG1			0x2018
+#define P2A_INT_STATUS			0x3060
+#define P2A_INT_STS_ALL			0xF
+#define P2A_INT_ENABLE			0x3070
+#define P2A_INT_ENA_ALL			0xF
+#define RP_LTSSM			0x3C64
+#define LTSSM_L0			0xF
+
+/* TLP configuration type 0 and 1 */
+#define TLP_FMTTYPE_CFGRD0		0x04	/* Configuration Read Type 0 */
+#define TLP_FMTTYPE_CFGWR0		0x44	/* Configuration Write Type 0 */
+#define TLP_FMTTYPE_CFGRD1		0x05	/* Configuration Read Type 1 */
+#define TLP_FMTTYPE_CFGWR1		0x45	/* Configuration Write Type 1 */
+#define TLP_PAYLOAD_SIZE		0x01
+#define TLP_READ_TAG			0x1D
+#define TLP_WRITE_TAG			0x10
+#define TLP_CFG_DW0(fmttype)		(((fmttype) << 24) | TLP_PAYLOAD_SIZE)
+#define TLP_CFG_DW1(reqid, tag, be)	(((reqid) << 16) | (tag << 8) | (be))
+#define TLP_CFG_DW2(bus, devfn, offset)	\
+				(((bus) << 24) | ((devfn) << 16) | (offset))
+#define TLP_REQ_ID(bus, devfn)		(((bus) << 8) | (devfn))
+#define TLP_COMPL_STATUS(hdr)		(((hdr) & 0xE0) >> 13)
+#define TLP_HDR_SIZE			3
+#define TLP_LOOP			500
+
+#define INTX_NUM		4
+
+#define DWORD_MASK		3
+
+struct altera_pcie {
+	struct platform_device	*pdev;
+	void __iomem		*cra_base;
+	int			irq;
+	u8			root_bus_nr;
+	struct irq_domain		*irq_domain;
+	struct resource		bus_range;
+	struct list_head		resources;
+};
+
+struct tlp_rp_regpair_t {
+	u32 ctrl;
+	u32 reg0;
+	u32 reg1;
+};
+
+static void altera_pcie_retrain(struct pci_dev *dev)
+{
+	u16 linkcap, linkstat;
+
+	/*
+	 * Set the retrain bit if the PCIe rootport support > 2.5GB/s, but
+	 * current speed is 2.5 GB/s.
+	 */
+	pcie_capability_read_word(dev, PCI_EXP_LNKCAP, &linkcap);
+
+	if ((linkcap & PCI_EXP_LNKCAP_SLS) <= PCI_EXP_LNKCAP_SLS_2_5GB)
+		return;
+
+	pcie_capability_read_word(dev, PCI_EXP_LNKSTA, &linkstat);
+	if ((linkstat & PCI_EXP_LNKSTA_CLS) == PCI_EXP_LNKSTA_CLS_2_5GB)
+		pcie_capability_set_word(dev, PCI_EXP_LNKCTL,
+					 PCI_EXP_LNKCTL_RL);
+}
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_ALTERA, PCI_ANY_ID, altera_pcie_retrain);
+
+static void altera_pcie_fixup_res(struct pci_dev *dev)
+{
+	/*
+	 * Prevent enumeration of root port.
+	 */
+	if (!dev->bus->parent && dev->devfn == 0) {
+		int i;
+
+		for (i = 0; i < PCI_NUM_RESOURCES; i++) {
+			dev->resource[i].start = 0;
+			dev->resource[i].end   = 0;
+			dev->resource[i].flags   = 0;
+		}
+	}
+}
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ALTERA, PCI_ANY_ID,
+			 altera_pcie_fixup_res);
+
+static inline void cra_writel(struct altera_pcie *pcie, const u32 value,
+			      const u32 reg)
+{
+	writel_relaxed(value, pcie->cra_base + reg);
+}
+
+static inline u32 cra_readl(struct altera_pcie *pcie, const u32 reg)
+{
+	return readl_relaxed(pcie->cra_base + reg);
+}
+
+static void tlp_write_tx(struct altera_pcie *pcie,
+			 struct tlp_rp_regpair_t *tlp_rp_regdata)
+{
+	cra_writel(pcie, tlp_rp_regdata->reg0, RP_TX_REG0);
+	cra_writel(pcie, tlp_rp_regdata->reg1, RP_TX_REG1);
+	cra_writel(pcie, tlp_rp_regdata->ctrl, RP_TX_CNTRL);
+}
+
+static bool altera_pcie_link_is_up(struct altera_pcie *pcie)
+{
+	return !!(cra_readl(pcie, RP_LTSSM) & LTSSM_L0);
+}
+
+static bool altera_pcie_valid_config(struct altera_pcie *pcie,
+				     struct pci_bus *bus, int dev)
+{
+	/* If there is no link, then there is no device */
+	if (bus->number != pcie->root_bus_nr) {
+		if (!altera_pcie_link_is_up(pcie))
+			return false;
+	}
+
+	/* access only one slot on each root port */
+	if (bus->number == pcie->root_bus_nr && dev > 0)
+		return false;
+
+	/*
+	 * Do not read more than one device on the bus directly attached
+	 * to root port, root port can only attach to one downstream port.
+	 */
+	if (bus->primary == pcie->root_bus_nr && dev > 0)
+		return false;
+
+	 return true;
+}
+
+static int tlp_read_packet(struct altera_pcie *pcie, u32 *value)
+{
+	u8 loop;
+	bool sop = 0;
+	u32 ctrl;
+	u32 reg0, reg1;
+
+	/*
+	 * Minimum 2 loops to read TLP headers and 1 loop to read data
+	 * payload.
+	 */
+	for (loop = 0; loop < TLP_LOOP; loop++) {
+		ctrl = cra_readl(pcie, RP_RXCPL_STATUS);
+		if ((ctrl & RP_RXCPL_SOP) || (ctrl & RP_RXCPL_EOP) || sop) {
+			reg0 = cra_readl(pcie, RP_RXCPL_REG0);
+			reg1 = cra_readl(pcie, RP_RXCPL_REG1);
+
+			if (ctrl & RP_RXCPL_SOP)
+				sop = true;
+
+			if (ctrl & RP_RXCPL_EOP) {
+				if (value)
+					*value = reg0;
+				return PCIBIOS_SUCCESSFUL;
+			}
+		}
+		udelay(5);
+	}
+
+	return -ENOENT;
+}
+
+static void tlp_write_packet(struct altera_pcie *pcie, u32 *headers,
+			     u32 data, bool align)
+{
+	struct tlp_rp_regpair_t tlp_rp_regdata;
+
+	tlp_rp_regdata.reg0 = headers[0];
+	tlp_rp_regdata.reg1 = headers[1];
+	tlp_rp_regdata.ctrl = RP_TX_SOP;
+	tlp_write_tx(pcie, &tlp_rp_regdata);
+
+	if (align) {
+		tlp_rp_regdata.reg0 = headers[2];
+		tlp_rp_regdata.reg1 = 0;
+		tlp_rp_regdata.ctrl = 0;
+		tlp_write_tx(pcie, &tlp_rp_regdata);
+
+		tlp_rp_regdata.reg0 = data;
+		tlp_rp_regdata.reg1 = 0;
+	} else {
+		tlp_rp_regdata.reg0 = headers[2];
+		tlp_rp_regdata.reg1 = data;
+	}
+
+	tlp_rp_regdata.ctrl = RP_TX_EOP;
+	tlp_write_tx(pcie, &tlp_rp_regdata);
+}
+
+static int tlp_cfg_dword_read(struct altera_pcie *pcie, u8 bus, u32 devfn,
+			      int where, u8 byte_en, u32 *value)
+{
+	u32 headers[TLP_HDR_SIZE];
+
+	if (bus == pcie->root_bus_nr)
+		headers[0] = TLP_CFG_DW0(TLP_FMTTYPE_CFGRD0);
+	else
+		headers[0] = TLP_CFG_DW0(TLP_FMTTYPE_CFGRD1);
+
+	headers[1] = TLP_CFG_DW1(TLP_REQ_ID(pcie->root_bus_nr, devfn),
+					TLP_READ_TAG, byte_en);
+	headers[2] = TLP_CFG_DW2(bus, devfn, where);
+
+	tlp_write_packet(pcie, headers, 0, false);
+
+	return tlp_read_packet(pcie, value);
+}
+
+static int tlp_cfg_dword_write(struct altera_pcie *pcie, u8 bus, u32 devfn,
+			       int where, u8 byte_en, u32 value)
+{
+	u32 headers[TLP_HDR_SIZE];
+	int ret;
+
+	if (bus == pcie->root_bus_nr)
+		headers[0] = TLP_CFG_DW0(TLP_FMTTYPE_CFGWR0);
+	else
+		headers[0] = TLP_CFG_DW0(TLP_FMTTYPE_CFGWR1);
+
+	headers[1] = TLP_CFG_DW1(TLP_REQ_ID(pcie->root_bus_nr, devfn),
+					TLP_WRITE_TAG, byte_en);
+	headers[2] = TLP_CFG_DW2(bus, devfn, where);
+
+	/* check alignment to Qword */
+	if ((where & 0x7) == 0)
+		tlp_write_packet(pcie, headers, value, true);
+	else
+		tlp_write_packet(pcie, headers, value, false);
+
+	ret = tlp_read_packet(pcie, NULL);
+	if (ret != PCIBIOS_SUCCESSFUL)
+		return ret;
+
+	/*
+	 * Monitoring changes to PCI_PRIMARY_BUS register on root port
+	 * and update local copy of root bus number accordingly.
+	 */
+	if ((bus == pcie->root_bus_nr) && (where == PCI_PRIMARY_BUS))
+		pcie->root_bus_nr = (u8)(value);
+
+	return PCIBIOS_SUCCESSFUL;
+}
+
+static int altera_pcie_cfg_read(struct pci_bus *bus, unsigned int devfn,
+				int where, int size, u32 *value)
+{
+	struct altera_pcie *pcie = bus->sysdata;
+	int ret;
+	u32 data;
+	u8 byte_en;
+
+	if (!altera_pcie_valid_config(pcie, bus, PCI_SLOT(devfn))) {
+		*value = 0xffffffff;
+		return PCIBIOS_DEVICE_NOT_FOUND;
+	}
+
+	switch (size) {
+	case 1:
+		byte_en = 1 << (where & 3);
+		break;
+	case 2:
+		byte_en = 3 << (where & 3);
+		break;
+	default:
+		byte_en = 0xf;
+		break;
+	}
+
+	ret = tlp_cfg_dword_read(pcie, bus->number, devfn,
+				 (where & ~DWORD_MASK), byte_en, &data);
+	if (ret != PCIBIOS_SUCCESSFUL)
+		return ret;
+
+	switch (size) {
+	case 1:
+		*value = (data >> (8 * (where & 0x3))) & 0xff;
+		break;
+	case 2:
+		*value = (data >> (8 * (where & 0x2))) & 0xffff;
+		break;
+	default:
+		*value = data;
+		break;
+	}
+
+	return PCIBIOS_SUCCESSFUL;
+}
+
+static int altera_pcie_cfg_write(struct pci_bus *bus, unsigned int devfn,
+				 int where, int size, u32 value)
+{
+	struct altera_pcie *pcie = bus->sysdata;
+	u32 data32;
+	u32 shift = 8 * (where & 3);
+	u8 byte_en;
+
+	if (!altera_pcie_valid_config(pcie, bus, PCI_SLOT(devfn)))
+		return PCIBIOS_DEVICE_NOT_FOUND;
+
+	switch (size) {
+	case 1:
+		data32 = (value & 0xff) << shift;
+		byte_en = 1 << (where & 3);
+		break;
+	case 2:
+		data32 = (value & 0xffff) << shift;
+		byte_en = 3 << (where & 3);
+		break;
+	default:
+		data32 = value;
+		byte_en = 0xf;
+		break;
+	}
+
+	return tlp_cfg_dword_write(pcie, bus->number, devfn,
+		(where & ~DWORD_MASK), byte_en, data32);
+}
+
+static struct pci_ops altera_pcie_ops = {
+	.read = altera_pcie_cfg_read,
+	.write = altera_pcie_cfg_write,
+};
+
+static int altera_pcie_intx_map(struct irq_domain *domain, unsigned int irq,
+				irq_hw_number_t hwirq)
+{
+	irq_set_chip_and_handler(irq, &dummy_irq_chip, handle_simple_irq);
+	irq_set_chip_data(irq, domain->host_data);
+
+	return 0;
+}
+
+static const struct irq_domain_ops intx_domain_ops = {
+	.map = altera_pcie_intx_map,
+};
+
+static void altera_pcie_isr(struct irq_desc *desc)
+{
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	struct altera_pcie *pcie;
+	unsigned long status;
+	u32 bit;
+	u32 virq;
+
+	chained_irq_enter(chip, desc);
+	pcie = irq_desc_get_handler_data(desc);
+
+	while ((status = cra_readl(pcie, P2A_INT_STATUS)
+		& P2A_INT_STS_ALL) != 0) {
+		for_each_set_bit(bit, &status, INTX_NUM) {
+			/* clear interrupts */
+			cra_writel(pcie, 1 << bit, P2A_INT_STATUS);
+
+			virq = irq_find_mapping(pcie->irq_domain, bit + 1);
+			if (virq)
+				generic_handle_irq(virq);
+			else
+				dev_err(&pcie->pdev->dev, "unexpected IRQ\n");
+		}
+	}
+
+	chained_irq_exit(chip, desc);
+}
+
+static void altera_pcie_release_of_pci_ranges(struct altera_pcie *pcie)
+{
+	pci_free_resource_list(&pcie->resources);
+}
+
+static int altera_pcie_parse_request_of_pci_ranges(struct altera_pcie *pcie)
+{
+	int err, res_valid = 0;
+	struct device *dev = &pcie->pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct resource_entry *win;
+
+	err = of_pci_get_host_bridge_resources(np, 0, 0xff, &pcie->resources,
+					       NULL);
+	if (err)
+		return err;
+
+	resource_list_for_each_entry(win, &pcie->resources) {
+		struct resource *parent, *res = win->res;
+
+		switch (resource_type(res)) {
+		case IORESOURCE_MEM:
+			parent = &iomem_resource;
+			res_valid |= !(res->flags & IORESOURCE_PREFETCH);
+			break;
+		default:
+			continue;
+		}
+
+		err = devm_request_resource(dev, parent, res);
+		if (err)
+			goto out_release_res;
+	}
+
+	if (!res_valid) {
+		dev_err(dev, "non-prefetchable memory resource required\n");
+		err = -EINVAL;
+		goto out_release_res;
+	}
+
+	return 0;
+
+out_release_res:
+	altera_pcie_release_of_pci_ranges(pcie);
+	return err;
+}
+
+static void altera_pcie_free_irq_domain(struct altera_pcie *pcie)
+{
+	int i;
+	u32 irq;
+
+	for (i = 0; i < INTX_NUM; i++) {
+		irq = irq_find_mapping(pcie->irq_domain, i + 1);
+		if (irq > 0)
+			irq_dispose_mapping(irq);
+	}
+
+	irq_domain_remove(pcie->irq_domain);
+}
+
+static int altera_pcie_init_irq_domain(struct altera_pcie *pcie)
+{
+	struct device *dev = &pcie->pdev->dev;
+	struct device_node *node = dev->of_node;
+
+	/* Setup INTx */
+	pcie->irq_domain = irq_domain_add_linear(node, INTX_NUM,
+					&intx_domain_ops, pcie);
+	if (!pcie->irq_domain) {
+		dev_err(dev, "Failed to get a INTx IRQ domain\n");
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static int altera_pcie_parse_dt(struct altera_pcie *pcie)
+{
+	struct resource *cra;
+	struct platform_device *pdev = pcie->pdev;
+
+	cra = platform_get_resource_byname(pdev, IORESOURCE_MEM, "Cra");
+	if (!cra) {
+		dev_err(&pdev->dev,
+			"no Cra memory resource defined\n");
+		return -ENODEV;
+	}
+
+	pcie->cra_base = devm_ioremap_resource(&pdev->dev, cra);
+	if (IS_ERR(pcie->cra_base)) {
+		dev_err(&pdev->dev, "failed to map cra memory\n");
+		return PTR_ERR(pcie->cra_base);
+	}
+
+	/* setup IRQ */
+	pcie->irq = platform_get_irq(pdev, 0);
+	if (pcie->irq <= 0) {
+		dev_err(&pdev->dev, "failed to get IRQ: %d\n", pcie->irq);
+		return -EINVAL;
+	}
+
+	irq_set_chained_handler_and_data(pcie->irq, altera_pcie_isr, pcie);
+
+	return 0;
+}
+
+static int altera_pcie_probe(struct platform_device *pdev)
+{
+	struct altera_pcie *pcie;
+	struct pci_bus *bus;
+	struct pci_bus *child;
+	int ret;
+
+	pcie = devm_kzalloc(&pdev->dev, sizeof(*pcie), GFP_KERNEL);
+	if (!pcie)
+		return -ENOMEM;
+
+	pcie->pdev = pdev;
+
+	ret = altera_pcie_parse_dt(pcie);
+	if (ret) {
+		dev_err(&pdev->dev, "Parsing DT failed\n");
+		return ret;
+	}
+
+	INIT_LIST_HEAD(&pcie->resources);
+
+	ret = altera_pcie_parse_request_of_pci_ranges(pcie);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed add resources\n");
+		return ret;
+	}
+
+	ret = altera_pcie_init_irq_domain(pcie);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed creating IRQ Domain\n");
+		return ret;
+	}
+
+	/* clear all interrupts */
+	cra_writel(pcie, P2A_INT_STS_ALL, P2A_INT_STATUS);
+	/* enable all interrupts */
+	cra_writel(pcie, P2A_INT_ENA_ALL, P2A_INT_ENABLE);
+
+	bus = pci_scan_root_bus(&pdev->dev, pcie->root_bus_nr, &altera_pcie_ops,
+				pcie, &pcie->resources);
+	if (!bus)
+		return -ENOMEM;
+
+	pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci);
+	pci_assign_unassigned_bus_resources(bus);
+	pci_bus_add_devices(bus);
+
+	/* Configure PCI Express setting. */
+	list_for_each_entry(child, &bus->children, node)
+		pcie_bus_configure_settings(child);
+
+	platform_set_drvdata(pdev, pcie);
+	return ret;
+}
+
+static int altera_pcie_remove(struct platform_device *pdev)
+{
+	struct altera_pcie *pcie = platform_get_drvdata(pdev);
+
+	altera_pcie_free_irq_domain(pcie);
+	platform_set_drvdata(pdev, NULL);
+	return 0;
+}
+
+static const struct of_device_id altera_pcie_of_match[] = {
+	{ .compatible = "altr,pcie-root-port-1.0", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, altera_pcie_of_match);
+
+static struct platform_driver altera_pcie_driver = {
+	.probe		= altera_pcie_probe,
+	.remove		= altera_pcie_remove,
+	.driver = {
+		.name	= "altera-pcie",
+		.of_match_table = altera_pcie_of_match,
+	},
+};
+
+module_platform_driver(altera_pcie_driver);
+
+MODULE_AUTHOR("Ley Foon Tan <lftan@altera.com>");
+MODULE_DESCRIPTION("Altera PCIe host controller driver");
+MODULE_LICENSE("GPL v2");