diff mbox series

[v9,19/20] PCI: starfive: Add JH7110 PCIe controller

Message ID 20231020104341.63157-20-minda.chen@starfivetech.com (mailing list archive)
State Superseded
Delegated to: Krzysztof WilczyƄski
Headers show
Series Refactoring Microchip PCIe driver and add StarFive PCIe | expand

Commit Message

Minda Chen Oct. 20, 2023, 10:43 a.m. UTC
Add StarFive JH7110 SoC PCIe controller platform
driver codes, JH7110 with PLDA host PCIe core.

Signed-off-by: Minda Chen <minda.chen@starfivetech.com>
Co-developed-by: Kevin Xie <kevin.xie@starfivetech.com>
Reviewed-by: Mason Huo <mason.huo@starfivetech.com>
---
 MAINTAINERS                                  |   7 +
 drivers/pci/controller/plda/Kconfig          |  12 +
 drivers/pci/controller/plda/Makefile         |   1 +
 drivers/pci/controller/plda/pcie-plda-host.c |  14 +
 drivers/pci/controller/plda/pcie-plda.h      |  75 +++-
 drivers/pci/controller/plda/pcie-starfive.c  | 448 +++++++++++++++++++
 6 files changed, 556 insertions(+), 1 deletion(-)
 create mode 100644 drivers/pci/controller/plda/pcie-starfive.c

Comments

Bjorn Helgaas Oct. 24, 2023, 5:52 p.m. UTC | #1
On Fri, Oct 20, 2023 at 06:43:40PM +0800, Minda Chen wrote:
> Add StarFive JH7110 SoC PCIe controller platform
> driver codes, JH7110 with PLDA host PCIe core.

Wrap all your commit logs to fill about 75 columns (as suggested
before).  "git log" adds a few spaces, so if you fill to 75 columns,
the result will still fit in a default 80 column window.

> +config PCIE_STARFIVE_HOST
> +	tristate "StarFive PCIe host controller"
> +	depends on OF && PCI_MSI
> +	select PCIE_PLDA_HOST
> +	help
> +	  Say Y here if you want to support the StarFive PCIe controller
> +	  in host mode. StarFive PCIe controller uses PLDA PCIe
> +	  core.

Add blank line between paragraphs.  Wrap to fill 75-78 columns.

> +	  If you choose to build this driver as module it will
> +	  be dynamically linked and module will be called
> +	  pcie-starfive.ko

> +++ b/drivers/pci/controller/plda/pcie-plda.h
> @@ -6,14 +6,26 @@
>  #ifndef _PCIE_PLDA_H
>  #define _PCIE_PLDA_H
>  
> +#include <linux/phy/phy.h>

I don't think you need to #include this.  In this file you only use a
pointer to struct phy, so declaring the struct should be enough, e.g.,

  struct phy;

You will have to #include it in pcie-starfive.c where you actually
*use* phy, of course.

> +#define CONFIG_SPACE_ADDR			0x1000u

This looks like an *offset* that you add to ->bridge_addr.  Adding two
addresses together doesn't really make sense.

> +static int starfive_pcie_config_write(struct pci_bus *bus, unsigned int devfn,
> +				      int where, int size, u32 value)
> +{
> +	if (starfive_pcie_hide_rc_bar(bus, devfn, where))
> +		return PCIBIOS_BAD_REGISTER_NUMBER;

I think this should probably return PCIBIOS_SUCCESSFUL.  There's
nothing wrong with the register number; you just want to pretend that
it's hardwired to zero.  That means ignore writes and always return 0
for reads.

> +	return pci_generic_config_write(bus, devfn, where, size, value);
> +}
> +
> +static int starfive_pcie_config_read(struct pci_bus *bus, unsigned int devfn,
> +				     int where, int size, u32 *value)
> +{
> +	if (starfive_pcie_hide_rc_bar(bus, devfn, where))
> +		return PCIBIOS_BAD_REGISTER_NUMBER;

Set *value to zero and return PCIBIOS_SUCCESSFUL.

> +	return pci_generic_config_read(bus, devfn, where, size, value);
> +}
> +
> +static int starfive_pcie_parse_dt(struct starfive_jh7110_pcie *pcie, struct device *dev)

95% of this driver (and the rest of drivers/pci) is wrapped to fit in
80 columns, e.g.,

  static int starfive_pcie_parse_dt(struct starfive_jh7110_pcie *pcie,
                                    struct device *dev)

> +	domain_nr = of_get_pci_domain_nr(dev->of_node);
> +
> +	if (domain_nr < 0 || domain_nr > 1)
> +		return dev_err_probe(dev, -ENODEV,
> +				     "failed to get valid pcie id\n");

"id" is too generic and doesn't hint about where the problem is.
Update the message ("pcie id") to mention "domain" so it corresponds
with the source ("linux,pci-domain" from DT).

> +	ret = reset_control_deassert(pcie->resets);
> +	if (ret) {
> +		clk_bulk_disable_unprepare(pcie->num_clks, pcie->clks);
> +		dev_err_probe(dev, ret, "failed to resets\n");

"failed to ... resets" is missing a word.  "Failed to deassert
resets", I guess?

> +	/* Ensure that PERST has been asserted for at least 100 ms,
> +	 * the sleep value is T_PVPERL from PCIe CEM spec r2.0 (Table 2-4)
> +	 */

Use multiline comment formatting (also below):

  /*
   * Ensure ...
   */

> +	msleep(100);
> +	if (pcie->reset_gpio)
> +		gpiod_set_value_cansleep(pcie->reset_gpio, 0);
> +
> +	/* As the requirement in PCIe base spec r6.0, system (<=5GT/s) must
> +	 * wait a minimum of 100 ms following exit from a conventional reset
> +	 * before sending a configuration request to the device.

Mention sec 6.6.1, where (I think) this value comes from.  Eventually
we should make a #define for this because it's not specific to any one
PCIe controller.

> +	msleep(100);
> +
> +	if (starfive_pcie_host_wait_for_link(pcie))
> +		dev_info(dev, "port link down\n");
> +
> +	return ret;

We know the value here, so return it explicitly:

  return 0;

> +static int starfive_pcie_suspend_noirq(struct device *dev)
> +{
> +	struct starfive_jh7110_pcie *pcie = dev_get_drvdata(dev);
> +
> +	if (!pcie)
> +		return 0;

How could it happen that "pcie" is zero?  I think it could only happen
if there were a driver bug or a memory corruption.  Either way, we
should remove the check so we take a NULL pointer fault and find out
about the problem.

> +static int starfive_pcie_resume_noirq(struct device *dev)
> +{
> +	struct starfive_jh7110_pcie *pcie = dev_get_drvdata(dev);
> +	int ret;
> +
> +	ret = starfive_pcie_enable_phy(dev, &pcie->plda);
> +	if (ret)
> +		return ret;
> +
> +	ret = clk_bulk_prepare_enable(pcie->num_clks, pcie->clks);
> +	if (ret) {
> +		dev_err(dev, "failed to enable clocks\n");
> +		starfive_pcie_disable_phy(&pcie->plda);
> +		return ret;
> +	}
> +
> +	return ret;

  return 0;

Bjorn
Kevin Xie Oct. 25, 2023, 6:24 a.m. UTC | #2
On 2023/10/25 1:52, Bjorn Helgaas wrote:
> On Fri, Oct 20, 2023 at 06:43:40PM +0800, Minda Chen wrote:
>> Add StarFive JH7110 SoC PCIe controller platform
>> driver codes, JH7110 with PLDA host PCIe core.
> 
> Wrap all your commit logs to fill about 75 columns (as suggested
> before).  "git log" adds a few spaces, so if you fill to 75 columns,
> the result will still fit in a default 80 column window.
> 

OK.

>> +config PCIE_STARFIVE_HOST
>> +	tristate "StarFive PCIe host controller"
>> +	depends on OF && PCI_MSI
>> +	select PCIE_PLDA_HOST
>> +	help
>> +	  Say Y here if you want to support the StarFive PCIe controller
>> +	  in host mode. StarFive PCIe controller uses PLDA PCIe
>> +	  core.
> 
> Add blank line between paragraphs.  Wrap to fill 75-78 columns.
> 

OK.

>> +	  If you choose to build this driver as module it will
>> +	  be dynamically linked and module will be called
>> +	  pcie-starfive.ko
> 
>> +++ b/drivers/pci/controller/plda/pcie-plda.h
>> @@ -6,14 +6,26 @@
>>  #ifndef _PCIE_PLDA_H
>>  #define _PCIE_PLDA_H
>>  
>> +#include <linux/phy/phy.h>
> 
> I don't think you need to #include this.  In this file you only use a
> pointer to struct phy, so declaring the struct should be enough, e.g.,
> 
>   struct phy;
> 
> You will have to #include it in pcie-starfive.c where you actually
> *use* phy, of course.
> 

OK.

>> +#define CONFIG_SPACE_ADDR			0x1000u
> 
> This looks like an *offset* that you add to ->bridge_addr.  Adding two
> addresses together doesn't really make sense.
> 

OK, I will rename it.

>> +static int starfive_pcie_config_write(struct pci_bus *bus, unsigned int devfn,
>> +				      int where, int size, u32 value)
>> +{
>> +	if (starfive_pcie_hide_rc_bar(bus, devfn, where))
>> +		return PCIBIOS_BAD_REGISTER_NUMBER;
> 
> I think this should probably return PCIBIOS_SUCCESSFUL.  There's
> nothing wrong with the register number; you just want to pretend that
> it's hardwired to zero.  That means ignore writes and always return 0
> for reads.
> 
>> +	return pci_generic_config_write(bus, devfn, where, size, value);
>> +}
>> +
>> +static int starfive_pcie_config_read(struct pci_bus *bus, unsigned int devfn,
>> +				     int where, int size, u32 *value)
>> +{
>> +	if (starfive_pcie_hide_rc_bar(bus, devfn, where))
>> +		return PCIBIOS_BAD_REGISTER_NUMBER;
> 
> Set *value to zero and return PCIBIOS_SUCCESSFUL.
> 

Agree, PCIBIOS_BAD_REGISTER_NUMBER is imprecise.
I will return PCIBIOS_SUCCESSFUL here, ignore writes and always return 0 for reads.

>> +	return pci_generic_config_read(bus, devfn, where, size, value);
>> +}
>> +
>> +static int starfive_pcie_parse_dt(struct starfive_jh7110_pcie *pcie, struct device *dev)
> 
> 95% of this driver (and the rest of drivers/pci) is wrapped to fit in
> 80 columns, e.g.,
> 
>   static int starfive_pcie_parse_dt(struct starfive_jh7110_pcie *pcie,
>                                     struct device *dev)
> 

Sorry, I will check and make them are wrapped to fit in 80 columns.

>> +	domain_nr = of_get_pci_domain_nr(dev->of_node);
>> +
>> +	if (domain_nr < 0 || domain_nr > 1)
>> +		return dev_err_probe(dev, -ENODEV,
>> +				     "failed to get valid pcie id\n");
> 
> "id" is too generic and doesn't hint about where the problem is.
> Update the message ("pcie id") to mention "domain" so it corresponds
> with the source ("linux,pci-domain" from DT).
>
Yes, domain is better.

>> +	ret = reset_control_deassert(pcie->resets);
>> +	if (ret) {
>> +		clk_bulk_disable_unprepare(pcie->num_clks, pcie->clks);
>> +		dev_err_probe(dev, ret, "failed to resets\n");
> 
> "failed to ... resets" is missing a word.  "Failed to deassert
> resets", I guess?
> 

Yes, I will make a supplement.

>> +	/* Ensure that PERST has been asserted for at least 100 ms,
>> +	 * the sleep value is T_PVPERL from PCIe CEM spec r2.0 (Table 2-4)
>> +	 */
> 
> Use multiline comment formatting (also below):
> 
>   /*
>    * Ensure ...
>    */
> 

OK.

>> +	msleep(100);
>> +	if (pcie->reset_gpio)
>> +		gpiod_set_value_cansleep(pcie->reset_gpio, 0);
>> +
>> +	/* As the requirement in PCIe base spec r6.0, system (<=5GT/s) must
>> +	 * wait a minimum of 100 ms following exit from a conventional reset
>> +	 * before sending a configuration request to the device.
> 
> Mention sec 6.6.1, where (I think) this value comes from.  Eventually
> we should make a #define for this because it's not specific to any one
> PCIe controller.
> 

I would like to add a new define in drivers/pci/pci.h:
/*
 * PCIe r6.0, sec 6.6.1, <Conventional Reset>
 * Requires a minimum waiting of 100ms before sending a configuration
 * request to the device.
 */
#define PCIE_BEFORE_CONFIG_REQUEST_WAIT_MS     100

When drivers use it, they can put them into the right place depends on the link speed:
1) With a Downstream Port(<=5.0 GT/s), system waits after conventional reset done.
2) With a Downstream Port(> 5.0 GT/s), system waits after link training completes. 

Thus, our code will be:
+	if (pcie->reset_gpio)
+		gpiod_set_value_cansleep(pcie->reset_gpio, 0);
+       /*
+        * With a Downstream Port (<=5GT/s), software must wait a minimum
+        * of 100ms following exit from a conventional reset before
+        * sending a configuration request to the device.
         */
-       msleep(100);
+       msleep(PCIE_BEFORE_CONFIG_REQUEST_WAIT_MS);

Is that what you expected?

>> +	msleep(100);
>> +
>> +	if (starfive_pcie_host_wait_for_link(pcie))
>> +		dev_info(dev, "port link down\n");
>> +
>> +	return ret;
> 
> We know the value here, so return it explicitly:
> 
>   return 0;
> 

OK

>> +static int starfive_pcie_suspend_noirq(struct device *dev)
>> +{
>> +	struct starfive_jh7110_pcie *pcie = dev_get_drvdata(dev);
>> +
>> +	if (!pcie)
>> +		return 0;
> 
> How could it happen that "pcie" is zero?  I think it could only happen
> if there were a driver bug or a memory corruption.  Either way, we
> should remove the check so we take a NULL pointer fault and find out
> about the problem.
> 

I will remove it.

>> +static int starfive_pcie_resume_noirq(struct device *dev)
>> +{
>> +	struct starfive_jh7110_pcie *pcie = dev_get_drvdata(dev);
>> +	int ret;
>> +
>> +	ret = starfive_pcie_enable_phy(dev, &pcie->plda);
>> +	if (ret)
>> +		return ret;
>> +
>> +	ret = clk_bulk_prepare_enable(pcie->num_clks, pcie->clks);
>> +	if (ret) {
>> +		dev_err(dev, "failed to enable clocks\n");
>> +		starfive_pcie_disable_phy(&pcie->plda);
>> +		return ret;
>> +	}
>> +
>> +	return ret;
> 
>   return 0;
> 

OK.

Thanks!

> Bjorn
diff mbox series

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index e622e793ca72..a4e8d9e71d11 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -16678,6 +16678,13 @@  S:	Maintained
 F:	Documentation/devicetree/bindings/pci/socionext,uniphier-pcie*
 F:	drivers/pci/controller/dwc/pcie-uniphier*
 
+PCIE DRIVER FOR STARFIVE JH71x0
+M:	Kevin Xie <kevin.xie@starfivetech.com>
+L:	linux-pci@vger.kernel.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/pci/starfive*
+F:	drivers/pci/controller/plda/pcie-starfive.c
+
 PCIE DRIVER FOR ST SPEAR13XX
 M:	Pratyush Anand <pratyush.anand@gmail.com>
 L:	linux-pci@vger.kernel.org
diff --git a/drivers/pci/controller/plda/Kconfig b/drivers/pci/controller/plda/Kconfig
index e54a82ee94f5..8de661730aa5 100644
--- a/drivers/pci/controller/plda/Kconfig
+++ b/drivers/pci/controller/plda/Kconfig
@@ -15,4 +15,16 @@  config PCIE_MICROCHIP_HOST
 	  Say Y here if you want kernel to support the Microchip AXI PCIe
 	  Host Bridge driver.
 
+config PCIE_STARFIVE_HOST
+	tristate "StarFive PCIe host controller"
+	depends on OF && PCI_MSI
+	select PCIE_PLDA_HOST
+	help
+	  Say Y here if you want to support the StarFive PCIe controller
+	  in host mode. StarFive PCIe controller uses PLDA PCIe
+	  core.
+	  If you choose to build this driver as module it will
+	  be dynamically linked and module will be called
+	  pcie-starfive.ko
+
 endmenu
diff --git a/drivers/pci/controller/plda/Makefile b/drivers/pci/controller/plda/Makefile
index 4340ab007f44..0ac6851bed48 100644
--- a/drivers/pci/controller/plda/Makefile
+++ b/drivers/pci/controller/plda/Makefile
@@ -1,3 +1,4 @@ 
 # SPDX-License-Identifier: GPL-2.0
 obj-$(CONFIG_PCIE_PLDA_HOST) += pcie-plda-host.o
 obj-$(CONFIG_PCIE_MICROCHIP_HOST) += pcie-microchip-host.o
+obj-$(CONFIG_PCIE_STARFIVE_HOST) += pcie-starfive.o
diff --git a/drivers/pci/controller/plda/pcie-plda-host.c b/drivers/pci/controller/plda/pcie-plda-host.c
index 052db70c3128..98476f083966 100644
--- a/drivers/pci/controller/plda/pcie-plda-host.c
+++ b/drivers/pci/controller/plda/pcie-plda-host.c
@@ -19,6 +19,15 @@ 
 
 #include "pcie-plda.h"
 
+void __iomem *plda_pcie_map_bus(struct pci_bus *bus, unsigned int devfn,
+				int where)
+{
+	struct plda_pcie_rp *pcie = bus->sysdata;
+
+	return pcie->config_base + PCIE_ECAM_OFFSET(bus->number, devfn, where);
+}
+EXPORT_SYMBOL_GPL(plda_pcie_map_bus);
+
 static void plda_handle_msi(struct irq_desc *desc)
 {
 	struct plda_pcie_rp *port = irq_desc_get_handler_data(desc);
@@ -587,6 +596,11 @@  int plda_pcie_host_init(struct plda_pcie_rp *port, struct pci_ops *ops)
 		return dev_err_probe(dev, PTR_ERR(port->config_base),
 				     "failed to map config memory\n");
 
+	port->phy = devm_phy_optional_get(dev, NULL);
+	if (IS_ERR(port->phy))
+		return dev_err_probe(dev, PTR_ERR(port->phy),
+				     "failed to get pcie phy\n");
+
 	bridge = devm_pci_alloc_host_bridge(dev, 0);
 	if (!bridge)
 		return dev_err_probe(dev, -ENOMEM,
diff --git a/drivers/pci/controller/plda/pcie-plda.h b/drivers/pci/controller/plda/pcie-plda.h
index ed99a51dd6e8..0cd057a89f00 100644
--- a/drivers/pci/controller/plda/pcie-plda.h
+++ b/drivers/pci/controller/plda/pcie-plda.h
@@ -6,14 +6,26 @@ 
 #ifndef _PCIE_PLDA_H
 #define _PCIE_PLDA_H
 
+#include <linux/phy/phy.h>
+
 /* Number of MSI IRQs */
 #define PLDA_MAX_NUM_MSI_IRQS			32
 
 /* PCIe Bridge Phy Regs */
+#define GEN_SETTINGS				0x80
+#define  RP_ENABLE				1
+#define PCIE_PCI_IDS_DW1			0x9c
+#define  IDS_CLASS_CODE_SHIFT			16
+#define  REVISION_ID_MASK			GENMASK(7, 0)
+#define  CLASS_CODE_ID_MASK			GENMASK(31, 8)
 #define PCIE_PCI_IRQ_DW0			0xa8
 #define  MSIX_CAP_MASK				BIT(31)
 #define  NUM_MSI_MSGS_MASK			GENMASK(6, 4)
 #define  NUM_MSI_MSGS_SHIFT			4
+#define PCI_MISC				0xb4
+#define  PHY_FUNCTION_DIS			BIT(15)
+#define PCIE_WINROM				0xfc
+#define  PREF_MEM_WIN_64_SUPPORT		BIT(3)
 
 #define IMASK_LOCAL				0x180
 #define  DMA_END_ENGINE_0_MASK			0x00000000u
@@ -66,6 +78,8 @@ 
 #define ISTATUS_HOST				0x18c
 #define IMSI_ADDR				0x190
 #define ISTATUS_MSI				0x194
+#define PMSG_SUPPORT_RX				0x3f0
+#define  PMSG_LTR_SUPPORT			BIT(2)
 
 /* PCIe Master table init defines */
 #define ATR0_PCIE_WIN0_SRCADDR_PARAM		0x600u
@@ -87,6 +101,8 @@ 
 #define  PCIE_TX_RX_INTERFACE			0x00000000u
 #define  PCIE_CONFIG_INTERFACE			0x00000001u
 
+#define CONFIG_SPACE_ADDR			0x1000u
+
 #define ATR_ENTRY_SIZE				32
 
 #define EVENT_A_ATR_EVT_POST_ERR		0
@@ -159,6 +175,7 @@  struct plda_pcie_rp {
 	struct plda_msi msi;
 	const struct plda_event_ops *event_ops;
 	const struct plda_pcie_host_ops *host_ops;
+	struct phy *phy;
 	void __iomem *bridge_addr;
 	void __iomem *config_base;
 	int irq;
@@ -176,6 +193,7 @@  struct plda_event {
 	int msi_event;
 };
 
+void __iomem *plda_pcie_map_bus(struct pci_bus *bus, unsigned int devfn, int where);
 int plda_init_interrupts(struct platform_device *pdev,
 			 struct plda_pcie_rp *port,
 			 const struct plda_event *event);
@@ -192,4 +210,59 @@  static inline void plda_set_default_msi(struct plda_msi *msi)
 	msi->vector_phy = IMSI_ADDR;
 	msi->num_vectors = PLDA_MAX_NUM_MSI_IRQS;
 }
-#endif
+
+static inline void plda_pcie_enable_root_port(struct plda_pcie_rp *plda)
+{
+	u32 value;
+
+	value = readl_relaxed(plda->bridge_addr + GEN_SETTINGS);
+	value |= RP_ENABLE;
+	writel_relaxed(value, plda->bridge_addr + GEN_SETTINGS);
+}
+
+static inline void plda_pcie_set_standard_class(struct plda_pcie_rp *plda)
+{
+	u32 value;
+
+	/* set class code and reserve revision id */
+	value = readl_relaxed(plda->bridge_addr + PCIE_PCI_IDS_DW1);
+	value &= REVISION_ID_MASK;
+	value |= (PCI_CLASS_BRIDGE_PCI << IDS_CLASS_CODE_SHIFT);
+	writel_relaxed(value, plda->bridge_addr + PCIE_PCI_IDS_DW1);
+}
+
+static inline void plda_pcie_set_pref_win_64bit(struct plda_pcie_rp *plda)
+{
+	u32 value;
+
+	value = readl_relaxed(plda->bridge_addr + PCIE_WINROM);
+	value |= PREF_MEM_WIN_64_SUPPORT;
+	writel_relaxed(value, plda->bridge_addr + PCIE_WINROM);
+}
+
+static inline void plda_pcie_disable_ltr(struct plda_pcie_rp *plda)
+{
+	u32 value;
+
+	value = readl_relaxed(plda->bridge_addr + PMSG_SUPPORT_RX);
+	value &= ~PMSG_LTR_SUPPORT;
+	writel_relaxed(value, plda->bridge_addr + PMSG_SUPPORT_RX);
+}
+
+static inline void plda_pcie_disable_func(struct plda_pcie_rp *plda)
+{
+	u32 value;
+
+	value = readl_relaxed(plda->bridge_addr + PCI_MISC);
+	value |= PHY_FUNCTION_DIS;
+	writel_relaxed(value, plda->bridge_addr + PCI_MISC);
+}
+
+static inline void plda_pcie_write_rc_bar(struct plda_pcie_rp *plda, u64 val)
+{
+	void __iomem *addr = plda->bridge_addr + CONFIG_SPACE_ADDR;
+
+	writel_relaxed(lower_32_bits(val), addr + PCI_BASE_ADDRESS_0);
+	writel_relaxed(upper_32_bits(val), addr + PCI_BASE_ADDRESS_1);
+}
+#endif /* _PCIE_PLDA_H */
diff --git a/drivers/pci/controller/plda/pcie-starfive.c b/drivers/pci/controller/plda/pcie-starfive.c
new file mode 100644
index 000000000000..a90bc85fd40b
--- /dev/null
+++ b/drivers/pci/controller/plda/pcie-starfive.c
@@ -0,0 +1,448 @@ 
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * PCIe host controller driver for StarFive JH7110 Soc.
+ *
+ * Copyright (C) 2023 StarFive Technology Co., Ltd.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/mfd/syscon.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/pm_runtime.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
+#include "../../pci.h"
+
+#include "pcie-plda.h"
+
+#define PCIE_FUNC_NUM			4
+
+/* system control */
+#define STG_SYSCON_PCIE0_BASE			0x48
+#define STG_SYSCON_PCIE1_BASE			0x1f8
+
+#define STG_SYSCON_ARFUNC_OFFSET		0x78
+#define STG_SYSCON_AXI4_SLVL_ARFUNC_MASK	 GENMASK(22, 8)
+#define STG_SYSCON_AXI4_SLVL_PHY_ARFUNC(x)	 FIELD_PREP(GENMASK(20, 17), x)
+#define STG_SYSCON_AWFUNC_OFFSET		0x7c
+#define STG_SYSCON_AXI4_SLVL_AWFUNC_MASK	 GENMASK(14, 0)
+#define STG_SYSCON_AXI4_SLVL_PHY_AWFUNC(x)	 FIELD_PREP(GENMASK(12, 9), x)
+#define STG_SYSCON_CLKREQ			 BIT(22)
+#define STG_SYSCON_CKREF_SRC_MASK		 GENMASK(19, 18)
+#define STG_SYSCON_RP_NEP_OFFSET		0xe8
+#define STG_SYSCON_K_RP_NEP			 BIT(8)
+#define STG_SYSCON_LNKSTA_OFFSET		0x170
+#define DATA_LINK_ACTIVE			 BIT(5)
+
+/* Parameters for the waiting for link up routine */
+#define LINK_WAIT_MAX_RETRIES	10
+#define LINK_WAIT_USLEEP_MIN	90000
+#define LINK_WAIT_USLEEP_MAX	100000
+
+struct starfive_jh7110_pcie {
+	struct plda_pcie_rp plda;
+	struct reset_control *resets;
+	struct clk_bulk_data *clks;
+	struct regmap *reg_syscon;
+	struct gpio_desc *power_gpio;
+	struct gpio_desc *reset_gpio;
+
+	unsigned int stg_pcie_base;
+	int num_clks;
+};
+
+/*
+ * The BAR0/1 of bridge should be hidden during enumeration to
+ * avoid the sizing and resource allocation by PCIe core.
+ */
+static bool starfive_pcie_hide_rc_bar(struct pci_bus *bus, unsigned int  devfn,
+				      int offset)
+{
+	if (pci_is_root_bus(bus) && !devfn &&
+	    (offset == PCI_BASE_ADDRESS_0 || offset == PCI_BASE_ADDRESS_1))
+		return true;
+
+	return false;
+}
+
+static int starfive_pcie_config_write(struct pci_bus *bus, unsigned int devfn,
+				      int where, int size, u32 value)
+{
+	if (starfive_pcie_hide_rc_bar(bus, devfn, where))
+		return PCIBIOS_BAD_REGISTER_NUMBER;
+
+	return pci_generic_config_write(bus, devfn, where, size, value);
+}
+
+static int starfive_pcie_config_read(struct pci_bus *bus, unsigned int devfn,
+				     int where, int size, u32 *value)
+{
+	if (starfive_pcie_hide_rc_bar(bus, devfn, where))
+		return PCIBIOS_BAD_REGISTER_NUMBER;
+
+	return pci_generic_config_read(bus, devfn, where, size, value);
+}
+
+static int starfive_pcie_parse_dt(struct starfive_jh7110_pcie *pcie, struct device *dev)
+{
+	int domain_nr;
+
+	pcie->num_clks = devm_clk_bulk_get_all(dev, &pcie->clks);
+	if (pcie->num_clks < 0)
+		return dev_err_probe(dev, -ENODEV,
+				     "failed to get pcie clocks\n");
+
+	pcie->resets = devm_reset_control_array_get_exclusive(dev);
+	if (IS_ERR(pcie->resets))
+		return dev_err_probe(dev, PTR_ERR(pcie->resets),
+				     "failed to get pcie resets");
+
+	pcie->reg_syscon =
+		syscon_regmap_lookup_by_phandle(dev->of_node,
+						"starfive,stg-syscon");
+
+	if (IS_ERR(pcie->reg_syscon))
+		return dev_err_probe(dev, PTR_ERR(pcie->reg_syscon),
+				     "failed to parse starfive,stg-syscon\n");
+
+	domain_nr = of_get_pci_domain_nr(dev->of_node);
+
+	if (domain_nr < 0 || domain_nr > 1)
+		return dev_err_probe(dev, -ENODEV,
+				     "failed to get valid pcie id\n");
+
+	if (domain_nr == 0)
+		pcie->stg_pcie_base = STG_SYSCON_PCIE0_BASE;
+	else
+		pcie->stg_pcie_base = STG_SYSCON_PCIE1_BASE;
+
+	pcie->reset_gpio = devm_gpiod_get_optional(dev, "perst", GPIOD_OUT_HIGH);
+	if (IS_ERR(pcie->reset_gpio))
+		return dev_err_probe(dev, PTR_ERR(pcie->reset_gpio),
+				     "failed to get perst-gpio\n");
+
+	pcie->power_gpio = devm_gpiod_get_optional(dev, "enable", GPIOD_OUT_LOW);
+	if (IS_ERR(pcie->power_gpio))
+		return dev_err_probe(dev, PTR_ERR(pcie->power_gpio),
+				     "failed to get power-gpio\n");
+
+	return 0;
+}
+
+static struct pci_ops starfive_pcie_ops = {
+	.map_bus	= plda_pcie_map_bus,
+	.read           = starfive_pcie_config_read,
+	.write          = starfive_pcie_config_write,
+};
+
+static int starfive_pcie_clk_rst_init(struct starfive_jh7110_pcie *pcie)
+{
+	struct device *dev = pcie->plda.dev;
+	int ret;
+
+	ret = clk_bulk_prepare_enable(pcie->num_clks, pcie->clks);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to enable clocks\n");
+
+	ret = reset_control_deassert(pcie->resets);
+	if (ret) {
+		clk_bulk_disable_unprepare(pcie->num_clks, pcie->clks);
+		dev_err_probe(dev, ret, "failed to resets\n");
+	}
+
+	return ret;
+}
+
+static void starfive_pcie_clk_rst_deinit(struct starfive_jh7110_pcie *pcie)
+{
+	reset_control_assert(pcie->resets);
+	clk_bulk_disable_unprepare(pcie->num_clks, pcie->clks);
+}
+
+static bool starfive_pcie_link_up(struct plda_pcie_rp *plda)
+{
+	struct starfive_jh7110_pcie *pcie =
+		container_of(plda, struct starfive_jh7110_pcie, plda);
+	int ret;
+	u32 stg_reg_val;
+
+	ret = regmap_read(pcie->reg_syscon,
+			  pcie->stg_pcie_base + STG_SYSCON_LNKSTA_OFFSET,
+			  &stg_reg_val);
+	if (ret) {
+		dev_err(pcie->plda.dev, "failed to read link status\n");
+		return false;
+	}
+
+	return !!(stg_reg_val & DATA_LINK_ACTIVE);
+}
+
+static int starfive_pcie_host_wait_for_link(struct starfive_jh7110_pcie *pcie)
+{
+	int retries;
+
+	/* Check if the link is up or not */
+	for (retries = 0; retries < LINK_WAIT_MAX_RETRIES; retries++) {
+		if (starfive_pcie_link_up(&pcie->plda)) {
+			dev_info(pcie->plda.dev, "port link up\n");
+			return 0;
+		}
+		usleep_range(LINK_WAIT_USLEEP_MIN, LINK_WAIT_USLEEP_MAX);
+	}
+
+	return -ETIMEDOUT;
+}
+
+static int starfive_pcie_enable_phy(struct device *dev, struct plda_pcie_rp *pcie)
+{
+	int ret;
+
+	if (!pcie->phy)
+		return 0;
+
+	ret = phy_init(pcie->phy);
+	if (ret)
+		return dev_err_probe(dev, ret,
+				     "failed to initialize pcie phy\n");
+
+	ret = phy_set_mode(pcie->phy, PHY_MODE_PCIE);
+	if (ret) {
+		dev_err_probe(dev, ret, "failed to set pcie mode\n");
+		goto err_phy_on;
+	}
+
+	ret = phy_power_on(pcie->phy);
+	if (ret) {
+		dev_err_probe(dev, ret, "failed to power on pcie phy\n");
+		goto err_phy_on;
+	}
+
+	return 0;
+
+err_phy_on:
+	phy_exit(pcie->phy);
+	return ret;
+}
+
+static void starfive_pcie_disable_phy(struct plda_pcie_rp *pcie)
+{
+	phy_power_off(pcie->phy);
+	phy_exit(pcie->phy);
+}
+
+static void starfive_pcie_host_deinit(struct plda_pcie_rp *plda)
+{
+	struct starfive_jh7110_pcie *pcie =
+		container_of(plda, struct starfive_jh7110_pcie, plda);
+
+	starfive_pcie_clk_rst_deinit(pcie);
+	if (pcie->power_gpio)
+		gpiod_set_value_cansleep(pcie->power_gpio, 0);
+	starfive_pcie_disable_phy(plda);
+}
+
+static int starfive_pcie_host_init(struct plda_pcie_rp *plda)
+{
+	struct starfive_jh7110_pcie *pcie =
+		container_of(plda, struct starfive_jh7110_pcie, plda);
+	struct device *dev = plda->dev;
+	int ret;
+	int i;
+
+	ret = starfive_pcie_enable_phy(dev, plda);
+	if (ret)
+		return ret;
+
+	regmap_update_bits(pcie->reg_syscon,
+			   pcie->stg_pcie_base + STG_SYSCON_RP_NEP_OFFSET,
+			   STG_SYSCON_K_RP_NEP, STG_SYSCON_K_RP_NEP);
+
+	regmap_update_bits(pcie->reg_syscon,
+			   pcie->stg_pcie_base + STG_SYSCON_AWFUNC_OFFSET,
+			   STG_SYSCON_CKREF_SRC_MASK,
+			   FIELD_PREP(STG_SYSCON_CKREF_SRC_MASK, 2));
+
+	regmap_update_bits(pcie->reg_syscon,
+			   pcie->stg_pcie_base + STG_SYSCON_AWFUNC_OFFSET,
+			   STG_SYSCON_CLKREQ, STG_SYSCON_CLKREQ);
+
+	ret = starfive_pcie_clk_rst_init(pcie);
+	if (ret)
+		return ret;
+
+	if (pcie->power_gpio)
+		gpiod_set_value_cansleep(pcie->power_gpio, 1);
+
+	if (pcie->reset_gpio)
+		gpiod_set_value_cansleep(pcie->reset_gpio, 1);
+
+	/* Disable physical functions except #0 */
+	for (i = 1; i < PCIE_FUNC_NUM; i++) {
+		regmap_update_bits(pcie->reg_syscon,
+				   pcie->stg_pcie_base + STG_SYSCON_ARFUNC_OFFSET,
+				   STG_SYSCON_AXI4_SLVL_ARFUNC_MASK,
+				   STG_SYSCON_AXI4_SLVL_PHY_ARFUNC(i));
+
+		regmap_update_bits(pcie->reg_syscon,
+				   pcie->stg_pcie_base + STG_SYSCON_AWFUNC_OFFSET,
+				   STG_SYSCON_AXI4_SLVL_AWFUNC_MASK,
+				   STG_SYSCON_AXI4_SLVL_PHY_AWFUNC(i));
+
+		plda_pcie_disable_func(plda);
+	}
+
+	regmap_update_bits(pcie->reg_syscon,
+			   pcie->stg_pcie_base + STG_SYSCON_ARFUNC_OFFSET,
+			   STG_SYSCON_AXI4_SLVL_ARFUNC_MASK, 0);
+	regmap_update_bits(pcie->reg_syscon,
+			   pcie->stg_pcie_base + STG_SYSCON_AWFUNC_OFFSET,
+			   STG_SYSCON_AXI4_SLVL_AWFUNC_MASK, 0);
+
+	plda_pcie_enable_root_port(plda);
+	plda_pcie_write_rc_bar(plda, 0);
+
+	/* PCIe PCI Standard Configuration Identification Settings. */
+	plda_pcie_set_standard_class(plda);
+
+	/*
+	 * The LTR message forwarding of PCIe Message Reception was set by core
+	 * as default, but the forward id & addr are also need to be reset.
+	 * If we do not disable LTR message forwarding here, or set a legal
+	 * forwarding address, the kernel will get stuck after this driver probe.
+	 * To workaround, disable the LTR message forwarding support on
+	 * PCIe Message Reception.
+	 */
+	plda_pcie_disable_ltr(plda);
+
+	/* Prefetchable memory window 64-bit addressing support */
+	plda_pcie_set_pref_win_64bit(plda);
+
+	/* Ensure that PERST has been asserted for at least 100 ms,
+	 * the sleep value is T_PVPERL from PCIe CEM spec r2.0 (Table 2-4)
+	 */
+	msleep(100);
+	if (pcie->reset_gpio)
+		gpiod_set_value_cansleep(pcie->reset_gpio, 0);
+
+	/* As the requirement in PCIe base spec r6.0, system (<=5GT/s) must
+	 * wait a minimum of 100 ms following exit from a conventional reset
+	 * before sending a configuration request to the device.
+	 */
+	msleep(100);
+
+	if (starfive_pcie_host_wait_for_link(pcie))
+		dev_info(dev, "port link down\n");
+
+	return ret;
+}
+
+static const struct plda_pcie_host_ops sf_host_ops = {
+	.host_init = starfive_pcie_host_init,
+	.host_deinit = starfive_pcie_host_deinit,
+};
+
+static int starfive_pcie_probe(struct platform_device *pdev)
+{
+	struct starfive_jh7110_pcie *pcie;
+	struct device *dev = &pdev->dev;
+	struct plda_pcie_rp *plda;
+	int ret;
+
+	pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL);
+	if (!pcie)
+		return -ENOMEM;
+
+	plda = &pcie->plda;
+	plda->dev = dev;
+
+	ret = starfive_pcie_parse_dt(pcie, dev);
+	if (ret)
+		return ret;
+
+	plda->host_ops = &sf_host_ops;
+	plda->num_events = NUM_PLDA_EVENTS;
+	ret = plda_pcie_host_init(&pcie->plda, &starfive_pcie_ops);
+	if (ret)
+		return ret;
+
+	pm_runtime_enable(&pdev->dev);
+	pm_runtime_get_sync(&pdev->dev);
+	platform_set_drvdata(pdev, pcie);
+
+	return 0;
+}
+
+static void starfive_pcie_remove(struct platform_device *pdev)
+{
+	struct starfive_jh7110_pcie *pcie = platform_get_drvdata(pdev);
+
+	plda_pcie_host_deinit(&pcie->plda);
+	platform_set_drvdata(pdev, NULL);
+}
+
+static int starfive_pcie_suspend_noirq(struct device *dev)
+{
+	struct starfive_jh7110_pcie *pcie = dev_get_drvdata(dev);
+
+	if (!pcie)
+		return 0;
+
+	clk_bulk_disable_unprepare(pcie->num_clks, pcie->clks);
+	starfive_pcie_disable_phy(&pcie->plda);
+
+	return 0;
+}
+
+static int starfive_pcie_resume_noirq(struct device *dev)
+{
+	struct starfive_jh7110_pcie *pcie = dev_get_drvdata(dev);
+	int ret;
+
+	ret = starfive_pcie_enable_phy(dev, &pcie->plda);
+	if (ret)
+		return ret;
+
+	ret = clk_bulk_prepare_enable(pcie->num_clks, pcie->clks);
+	if (ret) {
+		dev_err(dev, "failed to enable clocks\n");
+		starfive_pcie_disable_phy(&pcie->plda);
+		return ret;
+	}
+
+	return ret;
+}
+
+static const struct dev_pm_ops starfive_pcie_pm_ops = {
+	NOIRQ_SYSTEM_SLEEP_PM_OPS(starfive_pcie_suspend_noirq,
+				  starfive_pcie_resume_noirq)
+};
+
+static const struct of_device_id starfive_pcie_of_match[] = {
+	{ .compatible = "starfive,jh7110-pcie", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, starfive_pcie_of_match);
+
+static struct platform_driver starfive_pcie_driver = {
+	.driver = {
+		.name = "pcie-starfive",
+		.of_match_table = of_match_ptr(starfive_pcie_of_match),
+		.pm = pm_sleep_ptr(&starfive_pcie_pm_ops),
+	},
+	.probe = starfive_pcie_probe,
+	.remove_new = starfive_pcie_remove,
+};
+module_platform_driver(starfive_pcie_driver);
+
+MODULE_DESCRIPTION("StarFive JH7110 PCIe host driver");
+MODULE_LICENSE("GPL v2");