diff mbox series

[v8,2/2] PCI: amlogic: Add the Amlogic Meson PCIe controller driver

Message ID 1545120286-129258-3-git-send-email-hanjie.lin@amlogic.com (mailing list archive)
State Not Applicable
Headers show
Series add the Amlogic Meson PCIe controller driver | expand

Commit Message

Hanjie Lin Dec. 18, 2018, 8:04 a.m. UTC
From: Yue Wang <yue.wang@amlogic.com>

The Amlogic Meson PCIe host controller is based on the Synopsys DesignWare
PCI core. This patch adds the driver support for Meson PCIe controller.

Signed-off-by: Yue Wang <yue.wang@amlogic.com>
Signed-off-by: Hanjie Lin <hanjie.lin@amlogic.com>
---
 MAINTAINERS                            |   7 +
 drivers/pci/controller/dwc/Kconfig     |  10 +
 drivers/pci/controller/dwc/Makefile    |   1 +
 drivers/pci/controller/dwc/pci-meson.c | 595 +++++++++++++++++++++++++++++++++
 4 files changed, 613 insertions(+)
 create mode 100644 drivers/pci/controller/dwc/pci-meson.c

Comments

Bjorn Helgaas Dec. 18, 2018, 10:47 p.m. UTC | #1
On Tue, Dec 18, 2018 at 04:04:46PM +0800, Hanjie Lin wrote:
> From: Yue Wang <yue.wang@amlogic.com>
> 
> The Amlogic Meson PCIe host controller is based on the Synopsys DesignWare
> PCI core. This patch adds the driver support for Meson PCIe controller.

I don't have any comments on the code itself; just the trivial things
below.  No need to repost for these unless you're changing something
else.

I thought it looked very pretty overall, thanks for paying attention
to that!

> +static int meson_size_to_payload(struct meson_pcie *mp, int size)
> +{
> +	struct device *dev = mp->pci.dev;
> +
> +	/*
> +	 * dwc supports 2^(val+7) payload size, which val is 0~5 default to 1.
> +	 * So if input size is not 2^order alignment or less than 2^7 or bigger
> +	 * than 2^12, just set to default size 2^(1+7).
> +	 */
> +	if (!is_power_of_2(size) || size < 128 || size > 4096) {
> +		dev_warn(dev, "playload size %d, set to default 256\n", size);

s/playload/payload/

> +static void meson_set_max_payload(struct meson_pcie *mp, int size)
> +{
> +	u32 val = 0;

Unnecessary initialization.

> +	int max_payload_size = meson_size_to_payload(mp, size);
> +
> +	val = meson_elb_readl(mp, PCIE_DEV_CTRL_DEV_STUS);

> +static int meson_pcie_rd_own_conf(struct pcie_port *pp, int where, int size,
> +				  u32 *val)
> +{
> +	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> +	int ret;
> +
> +	ret = dw_pcie_read(pci->dbi_base + where, size, val);
> +	if (ret != PCIBIOS_SUCCESSFUL)
> +		return ret;
> +
> +	/*
> +	 * There is a bug in the MESON AXG pcie controller whereby software
> +	 * cannot programme the PCI_CLASS_DEVICE register, so we must fabricate
> +	 * the return value in the config accessors.

s/pcie/PCIe/
s/programme/program/ (IIUC, "programme" is British and only used as a
noun, where here you need a verb)

> +static int meson_pcie_link_up(struct dw_pcie *pci)
> +{
> +	struct meson_pcie *mp = to_meson_pcie(pci);
> +	struct device *dev = pci->dev;
> +	u32 smlh_up = 0;
> +	u32 ltssm_up = 0;
> +	u32 rdlh_up = 0;

Unnecessary initialization of smlh_up, ltssm_up, and rdlh_up.

> +	u32 speed_okay = 0;
> +	u32 cnt = 0;
> +	u32 state12, state17;
> +
> +	do {
> +		state12 = meson_cfg_readl(mp, PCIE_CFG_STATUS12);
> +		state17 = meson_cfg_readl(mp, PCIE_CFG_STATUS17);
> +		smlh_up = IS_SMLH_LINK_UP(state12);
> +		rdlh_up = IS_RDLH_LINK_UP(state12);
> +		ltssm_up = IS_LTSSM_UP(state12);

> +	dev_err(dev, "Error: Wait linkup timeout.\n");

Message doesn't match others from driver (capitalization and trailing
period).

> +			dev_err(dev, "failed to get msi irq\n");

s/msi irq/MSI IRQ/

> +	ret = meson_add_pcie_port(mp, pdev);
> +	if (ret < 0) {
> +		dev_err(dev, "Add PCIE port failed, %d\n", ret);

s/PCIE/PCIe/

All the messages in this function are capitalized differently than
other messages in the driver.

Bjorn
Hanjie Lin Dec. 19, 2018, 11:13 a.m. UTC | #2
On 2018/12/19 6:47, Bjorn Helgaas wrote:
> On Tue, Dec 18, 2018 at 04:04:46PM +0800, Hanjie Lin wrote:
>> From: Yue Wang <yue.wang@amlogic.com>
>>
>> The Amlogic Meson PCIe host controller is based on the Synopsys DesignWare
>> PCI core. This patch adds the driver support for Meson PCIe controller.
> 
> I don't have any comments on the code itself; just the trivial things
> below.  No need to repost for these unless you're changing something
> else.
> 
> I thought it looked very pretty overall, thanks for paying attention
> to that!
> 
>> +static int meson_size_to_payload(struct meson_pcie *mp, int size)
>> +{
>> +	struct device *dev = mp->pci.dev;
>> +
>> +	/*
>> +	 * dwc supports 2^(val+7) payload size, which val is 0~5 default to 1.
>> +	 * So if input size is not 2^order alignment or less than 2^7 or bigger
>> +	 * than 2^12, just set to default size 2^(1+7).
>> +	 */
>> +	if (!is_power_of_2(size) || size < 128 || size > 4096) {
>> +		dev_warn(dev, "playload size %d, set to default 256\n", size);
> 
> s/playload/payload/
> 
>> +static void meson_set_max_payload(struct meson_pcie *mp, int size)
>> +{
>> +	u32 val = 0;
> 
> Unnecessary initialization.
> 
>> +	int max_payload_size = meson_size_to_payload(mp, size);
>> +
>> +	val = meson_elb_readl(mp, PCIE_DEV_CTRL_DEV_STUS);
> 
>> +static int meson_pcie_rd_own_conf(struct pcie_port *pp, int where, int size,
>> +				  u32 *val)
>> +{
>> +	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
>> +	int ret;
>> +
>> +	ret = dw_pcie_read(pci->dbi_base + where, size, val);
>> +	if (ret != PCIBIOS_SUCCESSFUL)
>> +		return ret;
>> +
>> +	/*
>> +	 * There is a bug in the MESON AXG pcie controller whereby software
>> +	 * cannot programme the PCI_CLASS_DEVICE register, so we must fabricate
>> +	 * the return value in the config accessors.
> 
> s/pcie/PCIe/
> s/programme/program/ (IIUC, "programme" is British and only used as a
> noun, where here you need a verb)
> 
>> +static int meson_pcie_link_up(struct dw_pcie *pci)
>> +{
>> +	struct meson_pcie *mp = to_meson_pcie(pci);
>> +	struct device *dev = pci->dev;
>> +	u32 smlh_up = 0;
>> +	u32 ltssm_up = 0;
>> +	u32 rdlh_up = 0;
> 
> Unnecessary initialization of smlh_up, ltssm_up, and rdlh_up.
> 
>> +	u32 speed_okay = 0;
>> +	u32 cnt = 0;
>> +	u32 state12, state17;
>> +
>> +	do {
>> +		state12 = meson_cfg_readl(mp, PCIE_CFG_STATUS12);
>> +		state17 = meson_cfg_readl(mp, PCIE_CFG_STATUS17);
>> +		smlh_up = IS_SMLH_LINK_UP(state12);
>> +		rdlh_up = IS_RDLH_LINK_UP(state12);
>> +		ltssm_up = IS_LTSSM_UP(state12);
> 
>> +	dev_err(dev, "Error: Wait linkup timeout.\n");
> 
> Message doesn't match others from driver (capitalization and trailing
> period).
> 
>> +			dev_err(dev, "failed to get msi irq\n");
> 
> s/msi irq/MSI IRQ/
> 
>> +	ret = meson_add_pcie_port(mp, pdev);
>> +	if (ret < 0) {
>> +		dev_err(dev, "Add PCIE port failed, %d\n", ret);
> 
> s/PCIE/PCIe/
> 
> All the messages in this function are capitalized differently than
> other messages in the driver.
> 
> Bjorn
> 
> .
> 

hi Bjorn:

Thanks for the all suggestions and corrections.

There were too many code details unnecessary initialization, typing errors
and coding style etc. I will pay more attention to these rules and code-details
in the future patches also my daily work.

thanks again

hanjie.
Lorenzo Pieralisi Dec. 19, 2018, 3:13 p.m. UTC | #3
On Wed, Dec 19, 2018 at 07:13:47PM +0800, Hanjie Lin wrote:
> 
> 
> On 2018/12/19 6:47, Bjorn Helgaas wrote:
> > On Tue, Dec 18, 2018 at 04:04:46PM +0800, Hanjie Lin wrote:
> >> From: Yue Wang <yue.wang@amlogic.com>
> >>
> >> The Amlogic Meson PCIe host controller is based on the Synopsys DesignWare
> >> PCI core. This patch adds the driver support for Meson PCIe controller.
> > 
> > I don't have any comments on the code itself; just the trivial things
> > below.  No need to repost for these unless you're changing something
> > else.
> > 
> > I thought it looked very pretty overall, thanks for paying attention
> > to that!
> > 
> >> +static int meson_size_to_payload(struct meson_pcie *mp, int size)
> >> +{
> >> +	struct device *dev = mp->pci.dev;
> >> +
> >> +	/*
> >> +	 * dwc supports 2^(val+7) payload size, which val is 0~5 default to 1.
> >> +	 * So if input size is not 2^order alignment or less than 2^7 or bigger
> >> +	 * than 2^12, just set to default size 2^(1+7).
> >> +	 */
> >> +	if (!is_power_of_2(size) || size < 128 || size > 4096) {
> >> +		dev_warn(dev, "playload size %d, set to default 256\n", size);
> > 
> > s/playload/payload/
> > 
> >> +static void meson_set_max_payload(struct meson_pcie *mp, int size)
> >> +{
> >> +	u32 val = 0;
> > 
> > Unnecessary initialization.
> > 
> >> +	int max_payload_size = meson_size_to_payload(mp, size);
> >> +
> >> +	val = meson_elb_readl(mp, PCIE_DEV_CTRL_DEV_STUS);
> > 
> >> +static int meson_pcie_rd_own_conf(struct pcie_port *pp, int where, int size,
> >> +				  u32 *val)
> >> +{
> >> +	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> >> +	int ret;
> >> +
> >> +	ret = dw_pcie_read(pci->dbi_base + where, size, val);
> >> +	if (ret != PCIBIOS_SUCCESSFUL)
> >> +		return ret;
> >> +
> >> +	/*
> >> +	 * There is a bug in the MESON AXG pcie controller whereby software
> >> +	 * cannot programme the PCI_CLASS_DEVICE register, so we must fabricate
> >> +	 * the return value in the config accessors.
> > 
> > s/pcie/PCIe/
> > s/programme/program/ (IIUC, "programme" is British and only used as a
> > noun, where here you need a verb)
> > 
> >> +static int meson_pcie_link_up(struct dw_pcie *pci)
> >> +{
> >> +	struct meson_pcie *mp = to_meson_pcie(pci);
> >> +	struct device *dev = pci->dev;
> >> +	u32 smlh_up = 0;
> >> +	u32 ltssm_up = 0;
> >> +	u32 rdlh_up = 0;
> > 
> > Unnecessary initialization of smlh_up, ltssm_up, and rdlh_up.
> > 
> >> +	u32 speed_okay = 0;
> >> +	u32 cnt = 0;
> >> +	u32 state12, state17;
> >> +
> >> +	do {
> >> +		state12 = meson_cfg_readl(mp, PCIE_CFG_STATUS12);
> >> +		state17 = meson_cfg_readl(mp, PCIE_CFG_STATUS17);
> >> +		smlh_up = IS_SMLH_LINK_UP(state12);
> >> +		rdlh_up = IS_RDLH_LINK_UP(state12);
> >> +		ltssm_up = IS_LTSSM_UP(state12);
> > 
> >> +	dev_err(dev, "Error: Wait linkup timeout.\n");
> > 
> > Message doesn't match others from driver (capitalization and trailing
> > period).
> > 
> >> +			dev_err(dev, "failed to get msi irq\n");
> > 
> > s/msi irq/MSI IRQ/
> > 
> >> +	ret = meson_add_pcie_port(mp, pdev);
> >> +	if (ret < 0) {
> >> +		dev_err(dev, "Add PCIE port failed, %d\n", ret);
> > 
> > s/PCIE/PCIe/
> > 
> > All the messages in this function are capitalized differently than
> > other messages in the driver.
> > 
> > Bjorn
> > 
> > .
> > 
> 
> hi Bjorn:
> 
> Thanks for the all suggestions and corrections.
> 
> There were too many code details unnecessary initialization, typing errors
> and coding style etc. I will pay more attention to these rules and code-details
> in the future patches also my daily work.

I have merged your patches with Bjorn's suggestions in my pci/amlogic
branch, aiming at v4.21, please have a look.

Lorenzo
diff mbox series

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index 7fe120f..21ed916 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -11600,6 +11600,13 @@  T:	git git://git.kernel.org/pub/scm/linux/kernel/git/lpieralisi/pci.git/
 S:	Supported
 F:	drivers/pci/controller/
 
+PCIE DRIVER FOR AMLOGIC MESON
+M:	Yue Wang <yue.wang@Amlogic.com>
+L:	linux-pci@vger.kernel.org
+L:	linux-amlogic@lists.infradead.org
+S:	Maintained
+F:	drivers/pci/controller/dwc/pci-meson.c
+
 PCIE DRIVER FOR AXIS ARTPEC
 M:	Jesper Nilsson <jesper.nilsson@axis.com>
 L:	linux-arm-kernel@axis.com
diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
index 91b0194..7800322 100644
--- a/drivers/pci/controller/dwc/Kconfig
+++ b/drivers/pci/controller/dwc/Kconfig
@@ -193,4 +193,14 @@  config PCIE_HISI_STB
 	help
           Say Y here if you want PCIe controller support on HiSilicon STB SoCs
 
+config PCI_MESON
+	bool "MESON PCIe controller"
+	depends on PCI_MSI_IRQ_DOMAIN
+	select PCIE_DW_HOST
+	help
+	  Say Y here if you want to enable PCI controller support on Amlogic
+	  SoCs. The PCI controller on Amlogic is based on DesignWare hardware
+	  and therefore the driver re-uses the DesignWare core functions to
+	  implement the driver.
+
 endmenu
diff --git a/drivers/pci/controller/dwc/Makefile b/drivers/pci/controller/dwc/Makefile
index fcf91ea..e05a015 100644
--- a/drivers/pci/controller/dwc/Makefile
+++ b/drivers/pci/controller/dwc/Makefile
@@ -14,6 +14,7 @@  obj-$(CONFIG_PCIE_ARMADA_8K) += pcie-armada8k.o
 obj-$(CONFIG_PCIE_ARTPEC6) += pcie-artpec6.o
 obj-$(CONFIG_PCIE_KIRIN) += pcie-kirin.o
 obj-$(CONFIG_PCIE_HISI_STB) += pcie-histb.o
+obj-$(CONFIG_PCI_MESON) += pci-meson.o
 
 # The following drivers are for devices that use the generic ACPI
 # pci_root.c driver but don't support standard ECAM config access.
diff --git a/drivers/pci/controller/dwc/pci-meson.c b/drivers/pci/controller/dwc/pci-meson.c
new file mode 100644
index 0000000..7993f9d
--- /dev/null
+++ b/drivers/pci/controller/dwc/pci-meson.c
@@ -0,0 +1,595 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCIe host controller driver for Amlogic MESON SoCs
+ *
+ * Copyright (c) 2018 Amlogic, inc.
+ * Author: Yue Wang <yue.wang@amlogic.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/of_device.h>
+#include <linux/of_gpio.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+#include <linux/resource.h>
+#include <linux/types.h>
+
+#include "pcie-designware.h"
+
+#define to_meson_pcie(x) dev_get_drvdata((x)->dev)
+
+/* External local bus interface registers */
+#define PLR_OFFSET			0x700
+#define PCIE_PORT_LINK_CTRL_OFF		(PLR_OFFSET + 0x10)
+#define FAST_LINK_MODE			BIT(7)
+#define LINK_CAPABLE_MASK		GENMASK(21, 16)
+#define LINK_CAPABLE_X1			BIT(16)
+
+#define PCIE_GEN2_CTRL_OFF		(PLR_OFFSET + 0x10c)
+#define NUM_OF_LANES_MASK		GENMASK(12, 8)
+#define NUM_OF_LANES_X1			BIT(8)
+#define DIRECT_SPEED_CHANGE		BIT(17)
+
+#define TYPE1_HDR_OFFSET		0x0
+#define PCIE_STATUS_COMMAND		(TYPE1_HDR_OFFSET + 0x04)
+#define PCI_IO_EN			BIT(0)
+#define PCI_MEM_SPACE_EN		BIT(1)
+#define PCI_BUS_MASTER_EN		BIT(2)
+
+#define PCIE_BASE_ADDR0			(TYPE1_HDR_OFFSET + 0x10)
+#define PCIE_BASE_ADDR1			(TYPE1_HDR_OFFSET + 0x14)
+
+#define PCIE_CAP_OFFSET			0x70
+#define PCIE_DEV_CTRL_DEV_STUS		(PCIE_CAP_OFFSET + 0x08)
+#define PCIE_CAP_MAX_PAYLOAD_MASK	GENMASK(7, 5)
+#define PCIE_CAP_MAX_PAYLOAD_SIZE(x)	((x) << 5)
+#define PCIE_CAP_MAX_READ_REQ_MASK	GENMASK(14, 12)
+#define PCIE_CAP_MAX_READ_REQ_SIZE(x)	((x) << 12)
+
+/* PCIe specific config registers */
+#define PCIE_CFG0			0x0
+#define APP_LTSSM_ENABLE		BIT(7)
+
+#define PCIE_CFG_STATUS12		0x30
+#define IS_SMLH_LINK_UP(x)		((x) & (1 << 6))
+#define IS_RDLH_LINK_UP(x)		((x) & (1 << 16))
+#define IS_LTSSM_UP(x)			((((x) >> 10) & 0x1f) == 0x11)
+
+#define PCIE_CFG_STATUS17		0x44
+#define PM_CURRENT_STATE(x)		(((x) >> 7) & 0x1)
+
+#define WAIT_LINKUP_TIMEOUT		4000
+#define PORT_CLK_RATE			100000000UL
+#define MAX_PAYLOAD_SIZE		256
+#define MAX_READ_REQ_SIZE		256
+#define MESON_PCIE_PHY_POWERUP		0x1c
+#define PCIE_RESET_DELAY		500
+#define PCIE_SHARED_RESET		1
+#define PCIE_NORMAL_RESET		0
+
+enum pcie_data_rate {
+	PCIE_GEN1,
+	PCIE_GEN2,
+	PCIE_GEN3,
+	PCIE_GEN4
+};
+
+struct meson_pcie_mem_res {
+	void __iomem *elbi_base;
+	void __iomem *cfg_base;
+	void __iomem *phy_base;
+};
+
+struct meson_pcie_clk_res {
+	struct clk *clk;
+	struct clk *mipi_gate;
+	struct clk *port_clk;
+	struct clk *general_clk;
+};
+
+struct meson_pcie_rc_reset {
+	struct reset_control *phy;
+	struct reset_control *port;
+	struct reset_control *apb;
+};
+
+struct meson_pcie {
+	struct dw_pcie pci;
+	struct meson_pcie_mem_res mem_res;
+	struct meson_pcie_clk_res clk_res;
+	struct meson_pcie_rc_reset mrst;
+	struct gpio_desc *reset_gpio;
+};
+
+static struct reset_control *meson_pcie_get_reset(struct meson_pcie *mp,
+						  const char *id,
+						  u32 reset_type)
+{
+	struct device *dev = mp->pci.dev;
+	struct reset_control *reset;
+
+	if (reset_type == PCIE_SHARED_RESET)
+		reset = devm_reset_control_get_shared(dev, id);
+	else
+		reset = devm_reset_control_get(dev, id);
+
+	return reset;
+}
+
+static int meson_pcie_get_resets(struct meson_pcie *mp)
+{
+	struct meson_pcie_rc_reset *mrst = &mp->mrst;
+
+	mrst->phy = meson_pcie_get_reset(mp, "phy", PCIE_SHARED_RESET);
+	if (IS_ERR(mrst->phy))
+		return PTR_ERR(mrst->phy);
+	reset_control_deassert(mrst->phy);
+
+	mrst->port = meson_pcie_get_reset(mp, "port", PCIE_NORMAL_RESET);
+	if (IS_ERR(mrst->port))
+		return PTR_ERR(mrst->port);
+	reset_control_deassert(mrst->port);
+
+	mrst->apb = meson_pcie_get_reset(mp, "apb", PCIE_SHARED_RESET);
+	if (IS_ERR(mrst->apb))
+		return PTR_ERR(mrst->apb);
+	reset_control_deassert(mrst->apb);
+
+	return 0;
+}
+
+static void __iomem *meson_pcie_get_mem(struct platform_device *pdev,
+					struct meson_pcie *mp,
+					const char *id)
+{
+	struct device *dev = mp->pci.dev;
+	struct resource *res;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, id);
+
+	return devm_ioremap_resource(dev, res);
+}
+
+static void __iomem *meson_pcie_get_mem_shared(struct platform_device *pdev,
+					       struct meson_pcie *mp,
+					       const char *id)
+{
+	struct device *dev = mp->pci.dev;
+	struct resource *res;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, id);
+	if (!res) {
+		dev_err(dev, "No REG resource %s\n", id);
+		return ERR_PTR(-ENXIO);
+	}
+
+	return devm_ioremap(dev, res->start, resource_size(res));
+}
+
+static int meson_pcie_get_mems(struct platform_device *pdev,
+			       struct meson_pcie *mp)
+{
+	mp->mem_res.elbi_base = meson_pcie_get_mem(pdev, mp, "elbi");
+	if (IS_ERR(mp->mem_res.elbi_base))
+		return PTR_ERR(mp->mem_res.elbi_base);
+
+	mp->mem_res.cfg_base = meson_pcie_get_mem(pdev, mp, "cfg");
+	if (IS_ERR(mp->mem_res.cfg_base))
+		return PTR_ERR(mp->mem_res.cfg_base);
+
+	/* Meson SoC has two PCI controllers use same phy register*/
+	mp->mem_res.phy_base = meson_pcie_get_mem_shared(pdev, mp, "phy");
+	if (IS_ERR(mp->mem_res.phy_base))
+		return PTR_ERR(mp->mem_res.phy_base);
+
+	return 0;
+}
+
+static void meson_pcie_power_on(struct meson_pcie *mp)
+{
+	writel(MESON_PCIE_PHY_POWERUP, mp->mem_res.phy_base);
+}
+
+static void meson_pcie_reset(struct meson_pcie *mp)
+{
+	struct meson_pcie_rc_reset *mrst = &mp->mrst;
+
+	reset_control_assert(mrst->phy);
+	udelay(PCIE_RESET_DELAY);
+	reset_control_deassert(mrst->phy);
+	udelay(PCIE_RESET_DELAY);
+
+	reset_control_assert(mrst->port);
+	reset_control_assert(mrst->apb);
+	udelay(PCIE_RESET_DELAY);
+	reset_control_deassert(mrst->port);
+	reset_control_deassert(mrst->apb);
+	udelay(PCIE_RESET_DELAY);
+}
+
+static inline struct clk *meson_pcie_probe_clock(struct device *dev,
+						 const char *id, u64 rate)
+{
+	struct clk *clk;
+	int ret;
+
+	clk = devm_clk_get(dev, id);
+	if (IS_ERR(clk))
+		return clk;
+
+	if (rate) {
+		ret = clk_set_rate(clk, rate);
+		if (ret) {
+			dev_err(dev, "set clk rate failed, ret = %d\n", ret);
+			return ERR_PTR(ret);
+		}
+	}
+
+	ret = clk_prepare_enable(clk);
+	if (ret) {
+		dev_err(dev, "couldn't enable clk\n");
+		return ERR_PTR(ret);
+	}
+
+	devm_add_action_or_reset(dev,
+				 (void (*) (void *))clk_disable_unprepare,
+				 clk);
+
+	return clk;
+}
+
+static int meson_pcie_probe_clocks(struct meson_pcie *mp)
+{
+	struct device *dev = mp->pci.dev;
+	struct meson_pcie_clk_res *res = &mp->clk_res;
+
+	res->port_clk = meson_pcie_probe_clock(dev, "port", PORT_CLK_RATE);
+	if (IS_ERR(res->port_clk))
+		return PTR_ERR(res->port_clk);
+
+	res->mipi_gate = meson_pcie_probe_clock(dev, "pcie_mipi_en", 0);
+	if (IS_ERR(res->mipi_gate))
+		return PTR_ERR(res->mipi_gate);
+
+	res->general_clk = meson_pcie_probe_clock(dev, "pcie_general", 0);
+	if (IS_ERR(res->general_clk))
+		return PTR_ERR(res->general_clk);
+
+	res->clk = meson_pcie_probe_clock(dev, "pcie", 0);
+	if (IS_ERR(res->clk))
+		return PTR_ERR(res->clk);
+
+	return 0;
+}
+
+static inline void meson_elb_writel(struct meson_pcie *mp, u32 val, u32 reg)
+{
+	writel(val, mp->mem_res.elbi_base + reg);
+}
+
+static inline u32 meson_elb_readl(struct meson_pcie *mp, u32 reg)
+{
+	return readl(mp->mem_res.elbi_base + reg);
+}
+
+static inline u32 meson_cfg_readl(struct meson_pcie *mp, u32 reg)
+{
+	return readl(mp->mem_res.cfg_base + reg);
+}
+
+static inline void meson_cfg_writel(struct meson_pcie *mp, u32 val, u32 reg)
+{
+	writel(val, mp->mem_res.cfg_base + reg);
+}
+
+static void meson_pcie_assert_reset(struct meson_pcie *mp)
+{
+	gpiod_set_value_cansleep(mp->reset_gpio, 0);
+	udelay(500);
+	gpiod_set_value_cansleep(mp->reset_gpio, 1);
+}
+
+static void meson_pcie_init_dw(struct meson_pcie *mp)
+{
+	u32 val;
+
+	val = meson_cfg_readl(mp, PCIE_CFG0);
+	val |= APP_LTSSM_ENABLE;
+	meson_cfg_writel(mp, val, PCIE_CFG0);
+
+	val = meson_elb_readl(mp, PCIE_PORT_LINK_CTRL_OFF);
+	val &= ~LINK_CAPABLE_MASK;
+	meson_elb_writel(mp, val, PCIE_PORT_LINK_CTRL_OFF);
+
+	val = meson_elb_readl(mp, PCIE_PORT_LINK_CTRL_OFF);
+	val |= LINK_CAPABLE_X1 | FAST_LINK_MODE;
+	meson_elb_writel(mp, val, PCIE_PORT_LINK_CTRL_OFF);
+
+	val = meson_elb_readl(mp, PCIE_GEN2_CTRL_OFF);
+	val &= ~NUM_OF_LANES_MASK;
+	meson_elb_writel(mp, val, PCIE_GEN2_CTRL_OFF);
+
+	val = meson_elb_readl(mp, PCIE_GEN2_CTRL_OFF);
+	val |= NUM_OF_LANES_X1 | DIRECT_SPEED_CHANGE;
+	meson_elb_writel(mp, val, PCIE_GEN2_CTRL_OFF);
+
+	meson_elb_writel(mp, 0x0, PCIE_BASE_ADDR0);
+	meson_elb_writel(mp, 0x0, PCIE_BASE_ADDR1);
+}
+
+static int meson_size_to_payload(struct meson_pcie *mp, int size)
+{
+	struct device *dev = mp->pci.dev;
+
+	/*
+	 * dwc supports 2^(val+7) payload size, which val is 0~5 default to 1.
+	 * So if input size is not 2^order alignment or less than 2^7 or bigger
+	 * than 2^12, just set to default size 2^(1+7).
+	 */
+	if (!is_power_of_2(size) || size < 128 || size > 4096) {
+		dev_warn(dev, "playload size %d, set to default 256\n", size);
+		return 1;
+	}
+
+	return fls(size) - 8;
+}
+
+static void meson_set_max_payload(struct meson_pcie *mp, int size)
+{
+	u32 val = 0;
+	int max_payload_size = meson_size_to_payload(mp, size);
+
+	val = meson_elb_readl(mp, PCIE_DEV_CTRL_DEV_STUS);
+	val &= ~PCIE_CAP_MAX_PAYLOAD_MASK;
+	meson_elb_writel(mp, val, PCIE_DEV_CTRL_DEV_STUS);
+
+	val = meson_elb_readl(mp, PCIE_DEV_CTRL_DEV_STUS);
+	val |= PCIE_CAP_MAX_PAYLOAD_SIZE(max_payload_size);
+	meson_elb_writel(mp, val, PCIE_DEV_CTRL_DEV_STUS);
+}
+
+static void meson_set_max_rd_req_size(struct meson_pcie *mp, int size)
+{
+	u32 val;
+	int max_rd_req_size = meson_size_to_payload(mp, size);
+
+	val = meson_elb_readl(mp, PCIE_DEV_CTRL_DEV_STUS);
+	val &= ~PCIE_CAP_MAX_READ_REQ_MASK;
+	meson_elb_writel(mp, val, PCIE_DEV_CTRL_DEV_STUS);
+
+	val = meson_elb_readl(mp, PCIE_DEV_CTRL_DEV_STUS);
+	val |= PCIE_CAP_MAX_READ_REQ_SIZE(max_rd_req_size);
+	meson_elb_writel(mp, val, PCIE_DEV_CTRL_DEV_STUS);
+}
+
+static inline void meson_enable_memory_space(struct meson_pcie *mp)
+{
+	/* Set the RC Bus Master, Memory Space and I/O Space enables */
+	meson_elb_writel(mp, PCI_IO_EN | PCI_MEM_SPACE_EN | PCI_BUS_MASTER_EN,
+			 PCIE_STATUS_COMMAND);
+}
+
+static int meson_pcie_establish_link(struct meson_pcie *mp)
+{
+	struct dw_pcie *pci = &mp->pci;
+	struct pcie_port *pp = &pci->pp;
+
+	meson_pcie_init_dw(mp);
+	meson_set_max_payload(mp, MAX_PAYLOAD_SIZE);
+	meson_set_max_rd_req_size(mp, MAX_READ_REQ_SIZE);
+
+	dw_pcie_setup_rc(pp);
+	meson_enable_memory_space(mp);
+
+	meson_pcie_assert_reset(mp);
+
+	return dw_pcie_wait_for_link(pci);
+}
+
+static void meson_pcie_enable_interrupts(struct meson_pcie *mp)
+{
+	if (IS_ENABLED(CONFIG_PCI_MSI))
+		dw_pcie_msi_init(&mp->pci.pp);
+}
+
+static int meson_pcie_rd_own_conf(struct pcie_port *pp, int where, int size,
+				  u32 *val)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	int ret;
+
+	ret = dw_pcie_read(pci->dbi_base + where, size, val);
+	if (ret != PCIBIOS_SUCCESSFUL)
+		return ret;
+
+	/*
+	 * There is a bug in the MESON AXG pcie controller whereby software
+	 * cannot programme the PCI_CLASS_DEVICE register, so we must fabricate
+	 * the return value in the config accessors.
+	 */
+	if (where == PCI_CLASS_REVISION && size == 4)
+		*val = (PCI_CLASS_BRIDGE_PCI << 16) | (*val & 0xffff);
+	else if (where == PCI_CLASS_DEVICE && size == 2)
+		*val = PCI_CLASS_BRIDGE_PCI;
+	else if (where == PCI_CLASS_DEVICE && size == 1)
+		*val = PCI_CLASS_BRIDGE_PCI & 0xff;
+	else if (where == PCI_CLASS_DEVICE + 1 && size == 1)
+		*val = (PCI_CLASS_BRIDGE_PCI >> 8) & 0xff;
+
+	return PCIBIOS_SUCCESSFUL;
+}
+
+static int meson_pcie_wr_own_conf(struct pcie_port *pp, int where,
+				  int size, u32 val)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+
+	return dw_pcie_write(pci->dbi_base + where, size, val);
+}
+
+static int meson_pcie_link_up(struct dw_pcie *pci)
+{
+	struct meson_pcie *mp = to_meson_pcie(pci);
+	struct device *dev = pci->dev;
+	u32 smlh_up = 0;
+	u32 ltssm_up = 0;
+	u32 rdlh_up = 0;
+	u32 speed_okay = 0;
+	u32 cnt = 0;
+	u32 state12, state17;
+
+	do {
+		state12 = meson_cfg_readl(mp, PCIE_CFG_STATUS12);
+		state17 = meson_cfg_readl(mp, PCIE_CFG_STATUS17);
+		smlh_up = IS_SMLH_LINK_UP(state12);
+		rdlh_up = IS_RDLH_LINK_UP(state12);
+		ltssm_up = IS_LTSSM_UP(state12);
+
+		if (PM_CURRENT_STATE(state17) < PCIE_GEN3)
+			speed_okay = 1;
+
+		if (smlh_up)
+			dev_dbg(dev, "smlh_link_up is on\n");
+		if (rdlh_up)
+			dev_dbg(dev, "rdlh_link_up is on\n");
+		if (ltssm_up)
+			dev_dbg(dev, "ltssm_up is on\n");
+		if (speed_okay)
+			dev_dbg(dev, "speed_okay\n");
+
+		if (smlh_up && rdlh_up && ltssm_up && speed_okay)
+			return 1;
+
+		cnt++;
+
+		udelay(10);
+	} while (cnt < WAIT_LINKUP_TIMEOUT);
+
+	dev_err(dev, "Error: Wait linkup timeout.\n");
+	return 0;
+}
+
+static int meson_pcie_host_init(struct pcie_port *pp)
+{
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+	struct meson_pcie *mp = to_meson_pcie(pci);
+	int ret;
+
+	ret = meson_pcie_establish_link(mp);
+	if (ret)
+		return ret;
+
+	meson_pcie_enable_interrupts(mp);
+
+	return 0;
+}
+
+static const struct dw_pcie_host_ops meson_pcie_host_ops = {
+	.rd_own_conf = meson_pcie_rd_own_conf,
+	.wr_own_conf = meson_pcie_wr_own_conf,
+	.host_init = meson_pcie_host_init,
+};
+
+static int meson_add_pcie_port(struct meson_pcie *mp,
+			       struct platform_device *pdev)
+{
+	struct dw_pcie *pci = &mp->pci;
+	struct pcie_port *pp = &pci->pp;
+	struct device *dev = &pdev->dev;
+	int ret;
+
+	if (IS_ENABLED(CONFIG_PCI_MSI)) {
+		pp->msi_irq = platform_get_irq(pdev, 0);
+		if (pp->msi_irq < 0) {
+			dev_err(dev, "failed to get msi irq\n");
+			return pp->msi_irq;
+		}
+	}
+
+	pp->ops = &meson_pcie_host_ops;
+	pci->dbi_base = mp->mem_res.elbi_base;
+
+	ret = dw_pcie_host_init(pp);
+	if (ret) {
+		dev_err(dev, "failed to initialize host\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct dw_pcie_ops dw_pcie_ops = {
+	.link_up = meson_pcie_link_up,
+};
+
+static int meson_pcie_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct dw_pcie *pci;
+	struct meson_pcie *mp;
+	int ret;
+
+	mp = devm_kzalloc(dev, sizeof(*mp), GFP_KERNEL);
+	if (!mp)
+		return -ENOMEM;
+
+	pci = &mp->pci;
+	pci->dev = dev;
+	pci->ops = &dw_pcie_ops;
+
+	mp->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(mp->reset_gpio)) {
+		dev_err(dev, "Get reset gpio failed\n");
+		return PTR_ERR(mp->reset_gpio);
+	}
+
+	ret = meson_pcie_get_resets(mp);
+	if (ret) {
+		dev_err(dev, "Get reset resource failed, %d\n", ret);
+		return ret;
+	}
+
+	ret = meson_pcie_get_mems(pdev, mp);
+	if (ret) {
+		dev_err(dev, "Get memory resource failed, %d\n", ret);
+		return ret;
+	}
+
+	meson_pcie_power_on(mp);
+	meson_pcie_reset(mp);
+
+	ret = meson_pcie_probe_clocks(mp);
+	if (ret) {
+		dev_err(dev, "Init clock resources failed, %d\n", ret);
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, mp);
+
+	ret = meson_add_pcie_port(mp, pdev);
+	if (ret < 0) {
+		dev_err(dev, "Add PCIE port failed, %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct of_device_id meson_pcie_of_match[] = {
+	{
+		.compatible = "amlogic,axg-pcie",
+	},
+	{},
+};
+
+static struct platform_driver meson_pcie_driver = {
+	.probe = meson_pcie_probe,
+	.driver = {
+		.name = "meson-pcie",
+		.of_match_table = meson_pcie_of_match,
+	},
+};
+
+builtin_platform_driver(meson_pcie_driver);