[PATCH v3 14/26] PCI: keystone: Add support for PCIe RC in AM654x Platforms

Kishon Vijay Abraham I
2019-03-25T09:45:13Z

Add PCIe RC support for AM654x Platforms in pci-keystone.c

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
drivers/pci/controller/dwc/Kconfig | 2 +-
drivers/pci/controller/dwc/pci-keystone.c | 161 ++++++++++++++++++++--
2 files changed, 148 insertions(+), 15 deletions(-)

diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig
index 6ea74b1c0d94..d1d00833e0b3 100644
--- a/drivers/pci/controller/dwc/Kconfig
+++ b/drivers/pci/controller/dwc/Kconfig
@@ -104,7 +104,7 @@ config PCIE_SPEAR13XX

config PCI_KEYSTONE
bool "TI Keystone PCIe controller"
- depends on ARCH_KEYSTONE || (ARM && COMPILE_TEST)
+ depends on ARCH_KEYSTONE || ARCH_K3 || ((ARM || ARM64) && COMPILE_TEST)
depends on PCI_MSI_IRQ_DOMAIN
select PCIE_DW_HOST
help
diff --git a/drivers/pci/controller/dwc/pci-keystone.c b/drivers/pci/controller/dwc/pci-keystone.c
index 93296d434f40..a6a482bd648f 100644
--- a/drivers/pci/controller/dwc/pci-keystone.c
+++ b/drivers/pci/controller/dwc/pci-keystone.c
@@ -11,6 +11,7 @@

#include <linux/clk.h>
#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/irqchip/chained_irq.h>
@@ -18,6 +19,7 @@
#include <linux/mfd/syscon.h>
#include <linux/msi.h>
#include <linux/of.h>
+#include <linux/of_device.h>
#include <linux/of_irq.h>
#include <linux/of_pci.h>
#include <linux/phy/phy.h>
@@ -65,6 +67,7 @@
#define ERR_IRQ_STATUS 0x1c4
#define ERR_IRQ_ENABLE_SET 0x1c8
#define ERR_AER BIT(5) /* ECRC error */
+#define AM6_ERR_AER BIT(4) /* AM6 ECRC error */
#define ERR_AXI BIT(4) /* AXI tag lookup fatal error */
#define ERR_CORR BIT(3) /* Correctable error */
#define ERR_NONFATAL BIT(2) /* Non-fatal error */
@@ -88,8 +91,15 @@

#define KS_PCIE_SYSCLOCKOUTEN BIT(0)

+#define AM654_PCIE_DEV_TYPE_MASK 0x3
+
#define to_keystone_pcie(x) dev_get_drvdata((x)->dev)

+struct ks_pcie_of_data {
+ const struct dw_pcie_host_ops *host_ops;
+ unsigned int version;
+};
+
struct keystone_pcie {
struct dw_pcie *pci;
/* PCI Device ID */
@@ -109,6 +119,7 @@ struct keystone_pcie {
/* Application register space */
void __iomem *va_app_base; /* DT 1st resource */
struct resource app;
+ bool is_am6;
};

static u32 ks_pcie_app_readl(struct keystone_pcie *ks_pcie, u32 offset)
@@ -250,6 +261,16 @@ static void ks_pcie_handle_legacy_irq(struct keystone_pcie *ks_pcie,
ks_pcie_app_writel(ks_pcie, IRQ_EOI, offset);
}

+static int ks_pcie_am654_msi_host_init(struct pcie_port *pp)
+{
+ struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
+ struct device *dev = pci->dev;
+
+ dev_vdbg(dev, "dummy function so that DW core doesn't configure MSI\n");
+
+ return 0;
+}
+
static void ks_pcie_enable_error_irq(struct keystone_pcie *ks_pcie)
{
ks_pcie_app_writel(ks_pcie, ERR_IRQ_ENABLE_SET, ERR_IRQ_ALL);
@@ -276,10 +297,10 @@ static irqreturn_t ks_pcie_handle_error_irq(struct keystone_pcie *ks_pcie)
if (reg & ERR_CORR)
dev_dbg(dev, "Correctable Error\n");

- if (reg & ERR_AXI)
+ if (!ks_pcie->is_am6 && (reg & ERR_AXI))
dev_err(dev, "AXI tag lookup fatal Error\n");

- if (reg & ERR_AER)
+ if (reg & ERR_AER || (ks_pcie->is_am6 && (reg & AM6_ERR_AER)))
dev_err(dev, "ECRC Error\n");

ks_pcie_app_writel(ks_pcie, ERR_IRQ_STATUS, reg);
@@ -377,6 +398,9 @@ static void ks_pcie_setup_rc_app_regs(struct keystone_pcie *ks_pcie)
dw_pcie_writel_dbi(pci, PCI_BASE_ADDRESS_1, 0);
ks_pcie_clear_dbi_mode(ks_pcie);

+ if (ks_pcie->is_am6)
+ return;
+
val = ilog2(OB_WIN_SIZE);
ks_pcie_app_writel(ks_pcie, OB_SIZE, val);

@@ -619,6 +643,8 @@ static int ks_pcie_config_msi_irq(struct keystone_pcie *ks_pcie)

intc_np = of_get_child_by_name(np, "msi-interrupt-controller");
if (!intc_np) {
+ if (ks_pcie->is_am6)
+ return 0;
dev_warn(dev, "msi-interrupt-controller node is absent\n");
return -EINVAL;
}
@@ -668,6 +694,12 @@ static int ks_pcie_config_legacy_irq(struct keystone_pcie *ks_pcie)

intc_np = of_get_child_by_name(np, "legacy-interrupt-controller");
if (!intc_np) {
+ /*
+ * Since legacy interrupts are modeled as edge-interrupts in
+ * AM6, keep it disabled for now.
+ */
+ if (ks_pcie->is_am6)
+ return 0;
dev_warn(dev, "legacy-interrupt-controller node is absent\n");
return -EINVAL;
}
@@ -749,8 +781,10 @@ static int __init ks_pcie_init_id(struct keystone_pcie *ks_pcie)
if (ret)
return ret;

+ dw_pcie_dbi_ro_wr_en(pci);
dw_pcie_writew_dbi(pci, PCI_VENDOR_ID, id & PCIE_VENDORID_MASK);
dw_pcie_writew_dbi(pci, PCI_DEVICE_ID, id >> PCIE_DEVICEID_SHIFT);
+ dw_pcie_dbi_ro_wr_dis(pci);

return 0;
}
@@ -803,6 +837,11 @@ static const struct dw_pcie_host_ops ks_pcie_host_ops = {
.scan_bus = ks_pcie_v3_65_scan_bus,
};

+static const struct dw_pcie_host_ops ks_pcie_am654_host_ops = {
+ .host_init = ks_pcie_host_init,
+ .msi_host_init = ks_pcie_am654_msi_host_init,
+};
+
static irqreturn_t ks_pcie_err_irq_handler(int irq, void *priv)
{
struct keystone_pcie *ks_pcie = priv;
@@ -826,7 +865,6 @@ static int __init ks_pcie_add_pcie_port(struct keystone_pcie *ks_pcie,

pp->va_cfg1_base = pp->va_cfg0_base;

- pp->ops = &ks_pcie_host_ops;
ret = dw_pcie_host_init(pp);
if (ret) {
dev_err(dev, "failed to initialize host\n");
@@ -836,14 +874,6 @@ static int __init ks_pcie_add_pcie_port(struct keystone_pcie *ks_pcie,
return 0;
}

-static const struct of_device_id ks_pcie_of_match[] = {
- {
- .type = "pci",
- .compatible = "ti,keystone-pcie",
- },
- { },
-};
-
static const struct dw_pcie_ops ks_pcie_dw_pcie_ops = {
.start_link = ks_pcie_start_link,
.stop_link = ks_pcie_stop_link,
@@ -913,14 +943,67 @@ static int ks_pcie_set_mode(struct device *dev)
return 0;
}

+static int ks_pcie_am654_set_mode(struct device *dev)
+{
+ struct device_node *np = dev->of_node;
+ struct regmap *syscon;
+ u32 val;
+ u32 mask;
+ int ret = 0;
+
+ syscon = syscon_regmap_lookup_by_phandle(np, "ti,syscon-pcie-mode");
+ if (IS_ERR(syscon))
+ return 0;
+
+ mask = AM654_PCIE_DEV_TYPE_MASK;
+ val = RC;
+
+ ret = regmap_update_bits(syscon, 0, mask, val);
+ if (ret) {
+ dev_err(dev, "failed to set pcie mode\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static const struct ks_pcie_of_data ks_pcie_rc_of_data = {
+ .host_ops = &ks_pcie_host_ops,
+ .version = 0x365A,
+};
+
+static const struct ks_pcie_of_data ks_pcie_am654_rc_of_data = {
+ .host_ops = &ks_pcie_am654_host_ops,
+ .version = 0x490A,
+};
+
+static const struct of_device_id ks_pcie_of_match[] = {
+ {
+ .type = "pci",
+ .data = &ks_pcie_rc_of_data,
+ .compatible = "ti,keystone-pcie",
+ },
+ {
+ .data = &ks_pcie_am654_rc_of_data,
+ .compatible = "ti,am654-pcie-rc",
+ },
+ { },
+};
+
static int __init ks_pcie_probe(struct platform_device *pdev)
{
+ const struct dw_pcie_host_ops *host_ops;
struct device *dev = &pdev->dev;
struct device_node *np = dev->of_node;
+ const struct ks_pcie_of_data *data;
+ const struct of_device_id *match;
struct dw_pcie *pci;
struct keystone_pcie *ks_pcie;
struct device_link **link;
+ struct gpio_desc *gpiod;
+ void __iomem *atu_base;
struct resource *res;
+ unsigned int version;
void __iomem *base;
u32 num_viewport;
struct phy **phy;
@@ -930,6 +1013,14 @@ static int __init ks_pcie_probe(struct platform_device *pdev)
int irq;
int i;

+ match = of_match_device(of_match_ptr(ks_pcie_of_match), dev);
+ data = (struct ks_pcie_of_data *)match->data;
+ if (!data)
+ return -EINVAL;
+
+ version = data->version;
+ host_ops = data->host_ops;
+
ks_pcie = devm_kzalloc(dev, sizeof(*ks_pcie), GFP_KERNEL);
if (!ks_pcie)
return -ENOMEM;
@@ -950,9 +1041,13 @@ static int __init ks_pcie_probe(struct platform_device *pdev)
if (IS_ERR(base))
return PTR_ERR(base);

+ if (of_device_is_compatible(np, "ti,am654-pcie-rc"))
+ ks_pcie->is_am6 = true;
+
pci->dbi_base = base;
pci->dev = dev;
pci->ops = &ks_pcie_dw_pcie_ops;
+ pci->version = version;

ret = of_property_read_u32(np, "num-viewport", &num_viewport);
if (ret < 0) {
@@ -1011,6 +1106,15 @@ static int __init ks_pcie_probe(struct platform_device *pdev)
ks_pcie->num_viewport = num_viewport;
ks_pcie->phy = phy;

+ gpiod = devm_gpiod_get_optional(dev, "reset",
+ GPIOD_OUT_LOW);
+ if (IS_ERR(gpiod)) {
+ ret = PTR_ERR(gpiod);
+ if (ret != -EPROBE_DEFER)
+ dev_err(dev, "Failed to get reset GPIO\n");
+ goto err_link;
+ }
+
ret = ks_pcie_enable_phy(ks_pcie);
if (ret) {
dev_err(dev, "failed to enable phy\n");
@@ -1025,10 +1129,39 @@ static int __init ks_pcie_probe(struct platform_device *pdev)
goto err_get_sync;
}

- ret = ks_pcie_set_mode(dev);
- if (ret < 0)
- goto err_get_sync;
+ if (pci->version >= 0x480A) {
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "atu");
+ atu_base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(atu_base)) {
+ ret = PTR_ERR(atu_base);
+ goto err_get_sync;
+ }
+
+ pci->atu_base = atu_base;
+
+ ret = ks_pcie_am654_set_mode(dev);
+ if (ret < 0)
+ goto err_get_sync;
+ } else {
+ ret = ks_pcie_set_mode(dev);
+ if (ret < 0)
+ goto err_get_sync;
+ }
+
+ /*
+ * "Power Sequencing and Reset Signal Timings" table in
+ * PCI EXPRESS CARD ELECTROMECHANICAL SPECIFICATION, REV. 2.0
+ * indicates PERST# should be deasserted after minimum of 100us
+ * once REFCLK is stable. The REFCLK to the connector in RC
+ * mode is selected while enabling the PHY. So deassert PERST#
+ * after 100 us.
+ */
+ if (gpiod) {
+ usleep_range(100, 200);
+ gpiod_set_value_cansleep(gpiod, 1);
+ }

+ pci->pp.ops = host_ops;
ret = ks_pcie_add_pcie_port(ks_pcie, pdev);
if (ret < 0)
goto err_get_sync;
--
2.17.1