[PATCH v2 0/2] PCI: Add new Unisoc PCIe driver

[PATCH v2 0/2] PCI: Add new Unisoc PCIe driver

[Hongtao Wu]

From: Billows Wu <billows.wu@unisoc.com>

This series adds PCIe controller driver for Unisoc SoCs.
This controller is based on DesignWare PCIe IP.

Changes from v1:
1) Test this patch on top of Rob Herring's 40 part series of DWC clean-ups:
   https://lore.kernel.org/linux-pci/20200821035420.380495-1-robh@kernel.org/

2) Delete empty function

3) Document property "sprd,pcie-poweron-syscons" and
   'sprd,pcie-poweroff-syscons'

4) Delete runtime suspend/resume function

5) Add COMPILE_TEST which CONFIG_PCIE_SPRD depends on

Billows Wu (2):
  dt-bindings: PCI: sprd: Document Unisoc PCIe RC host controller
  PCI: sprd: Add support for Unisoc SoCs' PCIe controller

 .../devicetree/bindings/pci/sprd-pcie.yaml         | 101 +++++++++
 drivers/pci/controller/dwc/Kconfig                 |  13 ++
 drivers/pci/controller/dwc/Makefile                |   1 +
 drivers/pci/controller/dwc/pcie-sprd.c             | 231 +++++++++++++++++++++
 4 files changed, 346 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pci/sprd-pcie.yaml
 create mode 100644 drivers/pci/controller/dwc/pcie-sprd.c

-- 
2.7.4

[PATCH v2 1/2] dt-bindings: PCI: sprd: Document Unisoc PCIe RC host controller

[Hongtao Wu]

From: Billows Wu <billows.wu@unisoc.com>

This series adds PCIe bindings for Unisoc SoCs.
This controller is based on Designware PCIe IP.

Signed-off-by: Billows Wu <billows.wu@unisoc.com>
---
 .../devicetree/bindings/pci/sprd-pcie.yaml         | 101 +++++++++++++++++++++
 1 file changed, 101 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pci/sprd-pcie.yaml

diff --git a/Documentation/devicetree/bindings/pci/sprd-pcie.yaml b/Documentation/devicetree/bindings/pci/sprd-pcie.yaml
new file mode 100644
index 0000000..40c2408
--- /dev/null
+++ b/Documentation/devicetree/bindings/pci/sprd-pcie.yaml
@@ -0,0 +1,101 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pci/sprd-pcie.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: SoC PCIe Host Controller Device Tree Bindings
+
+maintainers:
+  - Billows Wu <billows.wu@unisoc.com>
+
+allOf:
+  - $ref: /schemas/pci/pci-bus.yaml#
+
+properties:
+  compatible:
+    items:
+      - const: sprd,pcie-rc
+
+  reg:
+    minItems: 2
+    items:
+      - description: Controller control and status registers.
+      - description: PCIe configuration registers.
+
+  reg-names:
+    items:
+      - const: dbi
+      - const: config
+
+  ranges:
+    maxItems: 2
+
+  num-lanes:
+    maximum: 1
+    description: Number of lanes to use for this port.
+
+  interrupts:
+    minItems: 1
+    description: Builtin MSI controller and PCIe host controller.
+
+  interrupt-names:
+    items:
+      - const: msi
+
+  sprd-pcie-poweron-syscons:
+    minItems: 1
+    description: Global register.
+      The first value is the phandle to the global registers required to
+      confige PCIe phy, clock and so on.
+      The second value is the global register type which indicates whether it
+      is a set/clear register or not.
+      The third value is the time to delay after the global register is set or
+      cleared.
+      The fourth value is the global register address.
+      The fifth value is the the mask value that the global register must
+      be operate.
+      The sixth value is the value that will be set to the global register.
+      Note that Some Unisoc global registers have not been upstreamed.
+      The global register and its mask can't be found in linux kernel,
+      so we use an offset address and a number to instead them.
+
+required:
+  - compatible
+  - reg
+  - reg-names
+  - num-lanes
+  - ranges
+  - interrupts
+  - interrupt-names
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+
+    ipa {
+        #address-cells = <2>;
+        #size-cells = <2>;
+
+        pcie0: pcie@2b100000 {
+            compatible = "sprd,pcie-rc";
+            reg = <0x0 0x2b100000 0x0 0x2000>,
+                  <0x2 0x00000000 0x0 0x2000>;
+            reg-names = "dbi", "config";
+            #address-cells = <3>;
+            #size-cells = <2>;
+            device_type = "pci";
+            ranges = <0x01000000 0x0 0x00000000 0x2 0x00002000 0x0 0x00010000>,
+                     <0x03000000 0x0 0x10000000 0x2 0x10000000 0x1 0xefffffff>;
+            num-lanes = <1>;
+            interrupts = <GIC_SPI 153 IRQ_TYPE_LEVEL_HIGH>;
+            interrupt-names = "msi";
+
+            sprd,pcie-poweron-syscons =
+                <&ap_ipa_ahb_regs 0 0 0x0000 0x40 0x40>,
+                <&ap_ipa_ahb_regs 0 0 0x0000 0x20 0x20>;
+            sprd,pcie-poweroff-syscons =
+                <&ap_ipa_ahb_regs 0 0 0x0000 0x20 0x0>,
+                <&ap_ipa_ahb_regs 0 0 0x0000 0x40 0x0>;
+        };
+    };
--
2.7.4

[PATCH v2 2/2] PCI: sprd: Add support for Unisoc SoCs' PCIe controller

[Hongtao Wu]

From: Billows Wu <billows.wu@unisoc.com>

This series adds PCIe controller driver for Unisoc SoCs.
This controller is based on DesignWare PCIe IP.

Signed-off-by: Billows Wu <billows.wu@unisoc.com>
---
 drivers/pci/controller/dwc/Kconfig     |  13 ++
 drivers/pci/controller/dwc/Makefile    |   1 +
 drivers/pci/controller/dwc/pcie-sprd.c | 231 +++++++++++++++++++++++++++++++++
 3 files changed, 245 insertions(+)
 create mode 100644 drivers/pci/controller/dwc/pcie-sprd.c

diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
index 044a376..14e8ed9 100644
--- a/drivers/pci/controller/dwc/Kconfig
+++ b/drivers/pci/controller/dwc/Kconfig
@@ -311,4 +311,17 @@ config PCIE_AL
 	  required only for DT-based platforms. ACPI platforms with the
 	  Annapurna Labs PCIe controller don't need to enable this.

+
+config PCIE_SPRD
+	tristate "Unisoc PCIe controller - RC mode"
+	depends on ARCH_SPRD || COMPILE_TEST
+	depends on PCI_MSI_IRQ_DOMAIN
+	select PCIE_DW_HOST
+	help
+	  Unisoc PCIe controller uses the Designware core. It can be configured
+	  as an Endpoint (EP) or a Root complex (RC). In order to enable RC
+	  mode, PCIE_SPRD must be selected.
+	  Say Y or M here if you want to PCIe RC controller support on Unisoc
+	  SoCs.
+
 endmenu
diff --git a/drivers/pci/controller/dwc/Makefile b/drivers/pci/controller/dwc/Makefile
index a751553..eb546e9 100644
--- a/drivers/pci/controller/dwc/Makefile
+++ b/drivers/pci/controller/dwc/Makefile
@@ -20,6 +20,7 @@ obj-$(CONFIG_PCI_MESON) += pci-meson.o
 obj-$(CONFIG_PCIE_TEGRA194) += pcie-tegra194.o
 obj-$(CONFIG_PCIE_UNIPHIER) += pcie-uniphier.o
 obj-$(CONFIG_PCIE_UNIPHIER_EP) += pcie-uniphier-ep.o
+obj-$(CONFIG_PCIE_SPRD) += pcie-sprd.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/pcie-sprd.c b/drivers/pci/controller/dwc/pcie-sprd.c
new file mode 100644
index 0000000..f5989ab
--- /dev/null
+++ b/drivers/pci/controller/dwc/pcie-sprd.c
@@ -0,0 +1,231 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCIe host controller driver for Unisoc SoCs
+ *
+ * Copyright (C) 2020 Unisoc, Inc.
+ *
+ * Author: Billows Wu <Billows.Wu@unisoc.com>
+ */
+
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+
+#include "pcie-designware.h"
+
+#define NUM_OF_ARGS 5
+
+struct sprd_pcie {
+	struct dw_pcie pci;
+};
+
+static int sprd_pcie_syscon_setting(struct platform_device *pdev, char *env)
+{
+	struct device_node *np = pdev->dev.of_node;
+	int i, count, err;
+	u32 type, delay, reg, mask, val, tmp_val;
+	struct of_phandle_args out_args;
+	struct regmap *iomap;
+	struct device *dev = &pdev->dev;
+
+	if (!of_find_property(np, env, NULL)) {
+		dev_info(dev, "There isn't property %s in dts\n", env);
+		return 0;
+	}
+
+	count = of_property_count_elems_of_size(np, env,
+					(NUM_OF_ARGS + 1) * sizeof(u32));
+	dev_info(dev, "Property (%s) reg count is %d :\n", env, count);
+
+	for (i = 0; i < count; i++) {
+		err = of_parse_phandle_with_fixed_args(np, env, NUM_OF_ARGS,
+						       i, &out_args);
+		if (err < 0)
+			return err;
+
+		type = out_args.args[0];
+		delay = out_args.args[1];
+		reg = out_args.args[2];
+		mask = out_args.args[3];
+		val = out_args.args[4];
+
+		iomap = syscon_node_to_regmap(out_args.np);
+
+		switch (type) {
+		case 0:
+			regmap_update_bits(iomap, reg, mask, val);
+			break;
+
+		case 1:
+			regmap_read(iomap, reg, &tmp_val);
+			tmp_val &= (~mask);
+			tmp_val |= (val & mask);
+			regmap_write(iomap, reg, tmp_val);
+			break;
+		default:
+			break;
+		}
+
+		if (delay)
+			usleep_range(delay, delay + 10);
+
+		regmap_read(iomap, reg, &tmp_val);
+		dev_dbg(&pdev->dev,
+			"%2d:reg[0x%8x] mask[0x%8x] val[0x%8x] result[0x%8x]\n",
+			i, reg, mask, val, tmp_val);
+	}
+
+	return i;
+}
+
+static int sprd_pcie_perst_assert(struct platform_device *pdev)
+{
+	return sprd_pcie_syscon_setting(pdev, "sprd,pcie-perst-assert");
+}
+
+static int sprd_pcie_perst_deassert(struct platform_device *pdev)
+{
+	return sprd_pcie_syscon_setting(pdev, "sprd,pcie-perst-deassert");
+}
+
+static int sprd_pcie_power_on(struct platform_device *pdev)
+{
+	int ret;
+	struct device *dev = &pdev->dev;
+
+	ret = sprd_pcie_syscon_setting(pdev, "sprd,pcie-poweron-syscons");
+	if (ret < 0)
+		dev_err(dev,
+			"failed to set pcie poweroff syscons, return %d\n",
+			ret);
+
+	sprd_pcie_perst_deassert(pdev);
+
+	return ret;
+}
+
+static int sprd_pcie_power_off(struct platform_device *pdev)
+{
+	int ret;
+	struct device *dev = &pdev->dev;
+
+	sprd_pcie_perst_assert(pdev);
+
+	ret = sprd_pcie_syscon_setting(pdev, "sprd,pcie-poweroff-syscons");
+	if (ret < 0)
+		dev_err(dev,
+			"failed to set pcie poweroff syscons, return %d\n",
+			ret);
+
+	return ret;
+}
+
+static int sprd_pcie_host_init(struct pcie_port *pp)
+{
+	int ret;
+	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+
+	dw_pcie_setup_rc(pp);
+	dw_pcie_msi_init(pp);
+
+	ret = dw_pcie_wait_for_link(pci);
+	if (ret)
+		dev_err(pci->dev, "pcie ep may has not been powered on yet\n");
+
+	return ret;
+}
+
+static const struct dw_pcie_host_ops sprd_pcie_host_ops = {
+	.host_init = sprd_pcie_host_init,
+};
+
+static int sprd_add_pcie_port(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct sprd_pcie *ctrl = platform_get_drvdata(pdev);
+	struct dw_pcie *pci = &ctrl->pci;
+	struct pcie_port *pp = &pci->pp;
+
+	pci->dbi_base = devm_platform_ioremap_resource_byname(pdev, "dbi");
+	if (IS_ERR(pci->dbi_base)) {
+		dev_err(dev, "failed to get rc dbi base\n");
+		return PTR_ERR(pci->dbi_base);
+	}
+
+	pp->ops = &sprd_pcie_host_ops;
+
+	if (IS_ENABLED(CONFIG_PCI_MSI)) {
+		pp->msi_irq = platform_get_irq_byname(pdev, "msi");
+		if (pp->msi_irq < 0) {
+			dev_err(dev, "failed to get msi, return %d\n",
+				pp->msi_irq);
+			return pp->msi_irq;
+		}
+	}
+
+	return dw_pcie_host_init(pp);
+}
+
+static int sprd_pcie_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct sprd_pcie *ctrl;
+	struct dw_pcie *pci;
+	int ret;
+
+	ctrl = devm_kzalloc(dev, sizeof(*ctrl), GFP_KERNEL);
+	if (!ctrl)
+		return -ENOMEM;
+
+	pci = &ctrl->pci;
+	pci->dev = dev;
+
+	platform_set_drvdata(pdev, ctrl);
+
+	ret = sprd_pcie_power_on(pdev);
+	if (ret < 0) {
+		dev_err(dev, "failed to get pcie poweron syscons, return %d\n",
+			ret);
+		goto err_power_off;
+	}
+
+	ret = sprd_add_pcie_port(pdev);
+	if (ret) {
+		dev_warn(dev, "failed to initialize RC controller\n");
+		return ret;
+	}
+
+	return 0;
+
+err_power_off:
+	sprd_pcie_power_off(pdev);
+
+	return ret;
+}
+
+static const struct of_device_id sprd_pcie_of_match[] = {
+	{
+		.compatible = "sprd,pcie-rc",
+	},
+	{},
+};
+
+static struct platform_driver sprd_pcie_driver = {
+	.probe = sprd_pcie_probe,
+	.driver = {
+		.name = "sprd-pcie",
+		.of_match_table = sprd_pcie_of_match,
+	},
+};
+
+module_platform_driver(sprd_pcie_driver);
+
+MODULE_DESCRIPTION("Unisoc PCIe host controller driver");
+MODULE_LICENSE("GPL v2");
--
2.7.4

Re: [PATCH v2 2/2] PCI: sprd: Add support for Unisoc SoCs' PCIe controller

[Bjorn Helgaas]

On Tue, Sep 08, 2020 at 09:47:21PM +0800, Hongtao Wu wrote:
> From: Billows Wu <billows.wu@unisoc.com>
> 
> This series adds PCIe controller driver for Unisoc SoCs.
> This controller is based on DesignWare PCIe IP.
> 
> Signed-off-by: Billows Wu <billows.wu@unisoc.com>

Last signed-off must be from developer submitting the patch, i.e.,
Hongtao Wu; see https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst#n560

> +config PCIE_SPRD
> +	tristate "Unisoc PCIe controller - RC mode"

s/RC mode/Host mode/ to follow convention of other drivers.

> +	depends on ARCH_SPRD || COMPILE_TEST
> +	depends on PCI_MSI_IRQ_DOMAIN
> +	select PCIE_DW_HOST
> +	help
> +	  Unisoc PCIe controller uses the Designware core. It can be configured

s/Designware/DesignWare/

> +	  as an Endpoint (EP) or a Root complex (RC). In order to enable RC
> +	  mode, PCIE_SPRD must be selected.
> +	  Say Y or M here if you want to PCIe RC controller support on Unisoc
> +	  SoCs.

> +		dev_dbg(&pdev->dev,

dev_dbg(dev, ...

> +			"%2d:reg[0x%8x] mask[0x%8x] val[0x%8x] result[0x%8x]\n",
> +			i, reg, mask, val, tmp_val);