[PATCH v4 12/23] PCI: dwc: dra7xx: Add EP mode support

From: Kishon Vijay Abraham I
Date: Mon Mar 13 2017 - 10:26:57 EST

The PCIe controller integrated in dra7xx SoCs is capable of operating
in endpoint mode. Add endpoint mode support to dra7xx driver.

Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
---
drivers/pci/dwc/Kconfig | 31 +++++-
drivers/pci/dwc/Makefile | 4 +-
drivers/pci/dwc/pci-dra7xx.c | 197 +++++++++++++++++++++++++++++++++++---
drivers/pci/dwc/pcie-designware.h | 7 ++
4 files changed, 221 insertions(+), 18 deletions(-)

diff --git a/drivers/pci/dwc/Kconfig b/drivers/pci/dwc/Kconfig
index 00335c71404e..96e6d17d2ae1 100644
--- a/drivers/pci/dwc/Kconfig
+++ b/drivers/pci/dwc/Kconfig
@@ -16,14 +16,37 @@ config PCIE_DW_EP

config PCI_DRA7XX
bool "TI DRA7xx PCIe controller"
- depends on PCI
+ depends on (PCI && PCI_MSI_IRQ_DOMAIN) || PCI_ENDPOINT
depends on OF && HAS_IOMEM && TI_PIPE3
+ help
+ Enables support for the PCIe controller in the DRA7xx SoC. There
+ are two instances of PCIe controller in DRA7xx. This controller can
+ work either as EP or RC. In order to enable host specific features
+ PCI_DRA7XX_HOST must be selected and in order to enable device
+ specific features PCI_DRA7XX_EP must be selected. This uses
+ the Designware core.
+
+if PCI_DRA7XX
+
+config PCI_DRA7XX_HOST
+ bool "PCI DRA7xx Host Mode"
+ depends on PCI
depends on PCI_MSI_IRQ_DOMAIN
select PCIE_DW_HOST
+ default y
help
- Enables support for the PCIe controller in the DRA7xx SoC. There
- are two instances of PCIe controller in DRA7xx. This controller can
- act both as EP and RC. This reuses the Designware core.
+ Enables support for the PCIe controller in the DRA7xx SoC to work in
+ host mode.
+
+config PCI_DRA7XX_EP
+ bool "PCI DRA7xx Endpoint Mode"
+ depends on PCI_ENDPOINT
+ select PCIE_DW_EP
+ help
+ Enables support for the PCIe controller in the DRA7xx SoC to work in
+ endpoint mode.
+
+endif

config PCIE_DW_PLAT
bool "Platform bus based DesignWare PCIe Controller"
diff --git a/drivers/pci/dwc/Makefile b/drivers/pci/dwc/Makefile
index b38425d36200..f31a8596442a 100644
--- a/drivers/pci/dwc/Makefile
+++ b/drivers/pci/dwc/Makefile
@@ -2,7 +2,9 @@ obj-$(CONFIG_PCIE_DW) += pcie-designware.o
obj-$(CONFIG_PCIE_DW_HOST) += pcie-designware-host.o
obj-$(CONFIG_PCIE_DW_EP) += pcie-designware-ep.o
obj-$(CONFIG_PCIE_DW_PLAT) += pcie-designware-plat.o
-obj-$(CONFIG_PCI_DRA7XX) += pci-dra7xx.o
+ifneq ($(filter y,$(CONFIG_PCI_DRA7XX_HOST) $(CONFIG_PCI_DRA7XX_EP)),)
+ obj-$(CONFIG_PCI_DRA7XX) += pci-dra7xx.o
+endif
obj-$(CONFIG_PCI_EXYNOS) += pci-exynos.o
obj-$(CONFIG_PCI_IMX6) += pci-imx6.o
obj-$(CONFIG_PCIE_SPEAR13XX) += pcie-spear13xx.o
diff --git a/drivers/pci/dwc/pci-dra7xx.c b/drivers/pci/dwc/pci-dra7xx.c
index d78974d20360..35c18534469c 100644
--- a/drivers/pci/dwc/pci-dra7xx.c
+++ b/drivers/pci/dwc/pci-dra7xx.c
@@ -10,12 +10,14 @@
* published by the Free Software Foundation.
*/

+#include <linux/delay.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/kernel.h>
#include <linux/init.h>
+#include <linux/of_device.h>
#include <linux/of_gpio.h>
#include <linux/of_pci.h>
#include <linux/pci.h>
@@ -57,6 +59,11 @@
#define MSI BIT(4)
#define LEG_EP_INTERRUPTS (INTA | INTB | INTC | INTD)

+#define PCIECTRL_TI_CONF_DEVICE_TYPE 0x0100
+#define DEVICE_TYPE_EP 0x0
+#define DEVICE_TYPE_LEG_EP 0x1
+#define DEVICE_TYPE_RC 0x4
+
#define PCIECTRL_DRA7XX_CONF_DEVICE_CMD 0x0104
#define LTSSM_EN 0x1

@@ -66,6 +73,13 @@

#define EXP_CAP_ID_OFFSET 0x70

+#define PCIECTRL_TI_CONF_INTX_ASSERT 0x0124
+#define PCIECTRL_TI_CONF_INTX_DEASSERT 0x0128
+
+#define PCIECTRL_TI_CONF_MSI_XMT 0x012c
+#define MSI_REQ_GRANT BIT(0)
+#define MSI_VECTOR_SHIFT 7
+
struct dra7xx_pcie {
struct dw_pcie *pci;
void __iomem *base; /* DT ti_conf */
@@ -73,6 +87,11 @@ struct dra7xx_pcie {
struct phy **phy;
int link_gen;
struct irq_domain *irq_domain;
+ enum dw_pcie_device_mode mode;
+};
+
+struct dra7xx_pcie_of_data {
+ enum dw_pcie_device_mode mode;
};

#define to_dra7xx_pcie(x) dev_get_drvdata((x)->dev)
@@ -101,9 +120,19 @@ static int dra7xx_pcie_link_up(struct dw_pcie *pci)
return !!(reg & LINK_UP);
}

-static int dra7xx_pcie_establish_link(struct dra7xx_pcie *dra7xx)
+static void dra7xx_pcie_stop_link(struct dw_pcie *pci)
{
- struct dw_pcie *pci = dra7xx->pci;
+ struct dra7xx_pcie *dra7xx = to_dra7xx_pcie(pci);
+ u32 reg;
+
+ reg = dra7xx_pcie_readl(dra7xx, PCIECTRL_DRA7XX_CONF_DEVICE_CMD);
+ reg &= ~LTSSM_EN;
+ dra7xx_pcie_writel(dra7xx, PCIECTRL_DRA7XX_CONF_DEVICE_CMD, reg);
+}
+
+static int dra7xx_pcie_establish_link(struct dw_pcie *pci)
+{
+ struct dra7xx_pcie *dra7xx = to_dra7xx_pcie(pci);
struct device *dev = pci->dev;
u32 reg;
u32 exp_cap_off = EXP_CAP_ID_OFFSET;
@@ -137,7 +166,7 @@ static int dra7xx_pcie_establish_link(struct dra7xx_pcie *dra7xx)
reg |= LTSSM_EN;
dra7xx_pcie_writel(dra7xx, PCIECTRL_DRA7XX_CONF_DEVICE_CMD, reg);

- return dw_pcie_wait_for_link(pci);
+ return 0;
}

static void dra7xx_pcie_enable_msi_interrupts(struct dra7xx_pcie *dra7xx)
@@ -171,7 +200,8 @@ static void dra7xx_pcie_host_init(struct pcie_port *pp)

dw_pcie_setup_rc(pp);

- dra7xx_pcie_establish_link(dra7xx);
+ dra7xx_pcie_establish_link(pci);
+ dw_pcie_wait_for_link(pci);
dw_pcie_msi_init(pp);
dra7xx_pcie_enable_interrupts(dra7xx);
}
@@ -249,6 +279,7 @@ static irqreturn_t dra7xx_pcie_irq_handler(int irq, void *arg)
struct dra7xx_pcie *dra7xx = arg;
struct dw_pcie *pci = dra7xx->pci;
struct device *dev = pci->dev;
+ struct dw_pcie_ep *ep = &pci->ep;
u32 reg;

reg = dra7xx_pcie_readl(dra7xx, PCIECTRL_DRA7XX_CONF_IRQSTATUS_MAIN);
@@ -285,8 +316,11 @@ static irqreturn_t dra7xx_pcie_irq_handler(int irq, void *arg)
if (reg & LINK_REQ_RST)
dev_dbg(dev, "Link Request Reset\n");

- if (reg & LINK_UP_EVT)
+ if (reg & LINK_UP_EVT) {
+ if (dra7xx->mode == DW_PCIE_EP_TYPE)
+ dw_pcie_ep_linkup(ep);
dev_dbg(dev, "Link-up state change\n");
+ }

if (reg & CFG_BME_EVT)
dev_dbg(dev, "CFG 'Bus Master Enable' change\n");
@@ -299,6 +333,94 @@ static irqreturn_t dra7xx_pcie_irq_handler(int irq, void *arg)
return IRQ_HANDLED;
}

+static void dra7xx_pcie_ep_init(struct dw_pcie_ep *ep)
+{
+ struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+ struct dra7xx_pcie *dra7xx = to_dra7xx_pcie(pci);
+
+ dra7xx_pcie_enable_wrapper_interrupts(dra7xx);
+}
+
+static void dra7xx_pcie_raise_legacy_irq(struct dra7xx_pcie *dra7xx)
+{
+ dra7xx_pcie_writel(dra7xx, PCIECTRL_TI_CONF_INTX_ASSERT, 0x1);
+ mdelay(1);
+ dra7xx_pcie_writel(dra7xx, PCIECTRL_TI_CONF_INTX_DEASSERT, 0x1);
+}
+
+static void dra7xx_pcie_raise_msi_irq(struct dra7xx_pcie *dra7xx,
+ u8 interrupt_num)
+{
+ u32 reg;
+
+ reg = (interrupt_num - 1) << MSI_VECTOR_SHIFT;
+ reg |= MSI_REQ_GRANT;
+ dra7xx_pcie_writel(dra7xx, PCIECTRL_TI_CONF_MSI_XMT, reg);
+}
+
+static int dra7xx_pcie_raise_irq(struct dw_pcie_ep *ep,
+ enum pci_epc_irq_type type, u8 interrupt_num)
+{
+ struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+ struct dra7xx_pcie *dra7xx = to_dra7xx_pcie(pci);
+
+ switch (type) {
+ case PCI_EPC_IRQ_LEGACY:
+ dra7xx_pcie_raise_legacy_irq(dra7xx);
+ break;
+ case PCI_EPC_IRQ_MSI:
+ dra7xx_pcie_raise_msi_irq(dra7xx, interrupt_num);
+ break;
+ default:
+ dev_err(pci->dev, "UNKNOWN IRQ type\n");
+ }
+
+ return 0;
+}
+
+static struct dw_pcie_ep_ops pcie_ep_ops = {
+ .ep_init = dra7xx_pcie_ep_init,
+ .raise_irq = dra7xx_pcie_raise_irq,
+};
+
+static int __init dra7xx_add_pcie_ep(struct dra7xx_pcie *dra7xx,
+ struct platform_device *pdev)
+{
+ int ret;
+ struct dw_pcie_ep *ep;
+ struct resource *res;
+ struct device *dev = &pdev->dev;
+ struct dw_pcie *pci = dra7xx->pci;
+
+ ep = &pci->ep;
+ ep->ops = &pcie_ep_ops;
+
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ep_dbics");
+ pci->dbi_base = devm_ioremap(dev, res->start, resource_size(res));
+ if (!pci->dbi_base)
+ return -ENOMEM;
+
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ep_dbics2");
+ pci->dbi_base2 = devm_ioremap(dev, res->start, resource_size(res));
+ if (!pci->dbi_base2)
+ return -ENOMEM;
+
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "addr_space");
+ if (!res)
+ return -EINVAL;
+
+ ep->phys_base = res->start;
+ ep->addr_size = resource_size(res);
+
+ ret = dw_pcie_ep_init(ep);
+ if (ret) {
+ dev_err(dev, "failed to initialize endpoint\n");
+ return ret;
+ }
+
+ return 0;
+}
+
static int __init dra7xx_add_pcie_port(struct dra7xx_pcie *dra7xx,
struct platform_device *pdev)
{
@@ -342,6 +464,8 @@ static int __init dra7xx_add_pcie_port(struct dra7xx_pcie *dra7xx,

static const struct dw_pcie_ops dw_pcie_ops = {
.cpu_addr_fixup = dra7xx_pcie_cpu_addr_fixup,
+ .start_link = dra7xx_pcie_establish_link,
+ .stop_link = dra7xx_pcie_stop_link,
.link_up = dra7xx_pcie_link_up,
};

@@ -384,6 +508,26 @@ static int dra7xx_pcie_enable_phy(struct dra7xx_pcie *dra7xx)
return ret;
}

+static const struct dra7xx_pcie_of_data dra7xx_pcie_rc_of_data = {
+ .mode = DW_PCIE_RC_TYPE,
+};
+
+static const struct dra7xx_pcie_of_data dra7xx_pcie_ep_of_data = {
+ .mode = DW_PCIE_EP_TYPE,
+};
+
+static const struct of_device_id of_dra7xx_pcie_match[] = {
+ {
+ .compatible = "ti,dra7-pcie",
+ .data = &dra7xx_pcie_rc_of_data,
+ },
+ {
+ .compatible = "ti,dra7-pcie-ep",
+ .data = &dra7xx_pcie_ep_of_data,
+ },
+ {},
+};
+
static int __init dra7xx_pcie_probe(struct platform_device *pdev)
{
u32 reg;
@@ -401,6 +545,16 @@ static int __init dra7xx_pcie_probe(struct platform_device *pdev)
struct device_node *np = dev->of_node;
char name[10];
struct gpio_desc *reset;
+ const struct of_device_id *match;
+ const struct dra7xx_pcie_of_data *data;
+ enum dw_pcie_device_mode mode;
+
+ match = of_match_device(of_match_ptr(of_dra7xx_pcie_match), dev);
+ if (!match)
+ return -EINVAL;
+
+ data = (struct dra7xx_pcie_of_data *)match->data;
+ mode = (enum dw_pcie_device_mode)data->mode;

dra7xx = devm_kzalloc(dev, sizeof(*dra7xx), GFP_KERNEL);
if (!dra7xx)
@@ -479,9 +633,25 @@ static int __init dra7xx_pcie_probe(struct platform_device *pdev)
if (dra7xx->link_gen < 0 || dra7xx->link_gen > 2)
dra7xx->link_gen = 2;

- ret = dra7xx_add_pcie_port(dra7xx, pdev);
- if (ret < 0)
- goto err_gpio;
+ switch (mode) {
+ case DW_PCIE_RC_TYPE:
+ dra7xx_pcie_writel(dra7xx, PCIECTRL_TI_CONF_DEVICE_TYPE,
+ DEVICE_TYPE_RC);
+ ret = dra7xx_add_pcie_port(dra7xx, pdev);
+ if (ret < 0)
+ goto err_gpio;
+ break;
+ case DW_PCIE_EP_TYPE:
+ dra7xx_pcie_writel(dra7xx, PCIECTRL_TI_CONF_DEVICE_TYPE,
+ DEVICE_TYPE_EP);
+ ret = dra7xx_add_pcie_ep(dra7xx, pdev);
+ if (ret < 0)
+ goto err_gpio;
+ break;
+ default:
+ dev_err(dev, "INVALID device type %d\n", mode);
+ }
+ dra7xx->mode = mode;

ret = devm_request_irq(dev, irq, dra7xx_pcie_irq_handler,
IRQF_SHARED, "dra7xx-pcie-main", dra7xx);
@@ -509,6 +679,9 @@ static int dra7xx_pcie_suspend(struct device *dev)
struct dw_pcie *pci = dra7xx->pci;
u32 val;

+ if (dra7xx->mode != DW_PCIE_RC_TYPE)
+ return 0;
+
/* clear MSE */
val = dw_pcie_readl_dbi(pci, PCI_COMMAND);
val &= ~PCI_COMMAND_MEMORY;
@@ -523,6 +696,9 @@ static int dra7xx_pcie_resume(struct device *dev)
struct dw_pcie *pci = dra7xx->pci;
u32 val;

+ if (dra7xx->mode != DW_PCIE_RC_TYPE)
+ return 0;
+
/* set MSE */
val = dw_pcie_readl_dbi(pci, PCI_COMMAND);
val |= PCI_COMMAND_MEMORY;
@@ -561,11 +737,6 @@ static const struct dev_pm_ops dra7xx_pcie_pm_ops = {
dra7xx_pcie_resume_noirq)
};

-static const struct of_device_id of_dra7xx_pcie_match[] = {
- { .compatible = "ti,dra7-pcie", },
- {},
-};
-
static struct platform_driver dra7xx_pcie_driver = {
.driver = {
.name = "dra7-pcie",
diff --git a/drivers/pci/dwc/pcie-designware.h b/drivers/pci/dwc/pcie-designware.h
index 3cafba40abbc..c6a840575796 100644
--- a/drivers/pci/dwc/pcie-designware.h
+++ b/drivers/pci/dwc/pcie-designware.h
@@ -120,6 +120,13 @@ enum dw_pcie_region_type {
DW_PCIE_REGION_OUTBOUND,
};

+enum dw_pcie_device_mode {
+ DW_PCIE_UNKNOWN_TYPE,
+ DW_PCIE_EP_TYPE,
+ DW_PCIE_LEG_EP_TYPE,
+ DW_PCIE_RC_TYPE,
+};
+
struct dw_pcie_host_ops {
int (*rd_own_conf)(struct pcie_port *pp, int where, int size, u32 *val);
int (*wr_own_conf)(struct pcie_port *pp, int where, int size, u32 val);
--
2.11.0