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oxnas: pcie: model shared resource as external pcie-phy driver

Refactor pcie-oxnas to have shared resources in syscon and new pcie-phy
driver. Hopefully this revives PCIe...

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
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dangowrt committed Mar 4, 2019
1 parent 3bb9dcf commit e7aa4c0db7eb3e81163682f570a9aecbb9fa8aed
@@ -278,6 +278,8 @@ CONFIG_PERF_EVENTS=y
CONFIG_PERF_USE_VMALLOC=y
CONFIG_PGTABLE_LEVELS=2
CONFIG_PHYLIB=y
CONFIG_GENERIC_PHY=y
CONFIG_PHY_OXNAS=y
CONFIG_PINCTRL=y
CONFIG_PINCTRL_OXNAS=y
# CONFIG_PINCTRL_SINGLE is not set
@@ -25,6 +25,8 @@
#include <linux/gpio.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/phy.h>
#include <linux/phy/phy.h>
#include <linux/regmap.h>
#include <linux/reset.h>
#include <linux/io.h>
@@ -75,23 +77,6 @@ enum {
PCIE_OBTRANS = BIT(12),
};

enum {
HCSL_BIAS_ON = BIT(0),
HCSL_PCIE_EN = BIT(1),
HCSL_PCIEA_EN = BIT(2),
HCSL_PCIEB_EN = BIT(3),
};

enum {
/* pcie phy reg offset */
PHY_ADDR = 0,
PHY_DATA = 4,
/* phy data reg bits */
READ_EN = BIT(16),
WRITE_EN = BIT(17),
CAP_DATA = BIT(18),
};

/* core config registers */
enum {
PCI_CONFIG_VERSION_DEVICEID = 0,
@@ -127,9 +112,6 @@ enum {
PCIE_SLAVE_BE_SHIFT = 22,
};

#define ADDR_VAL(val) ((val) & 0xFFFF)
#define DATA_VAL(val) ((val) & 0xFFFF)

#define PCIE_SLAVE_BE(val) ((val) << PCIE_SLAVE_BE_SHIFT)
#define PCIE_SLAVE_BE_MASK PCIE_SLAVE_BE(0xF)

@@ -146,7 +128,7 @@ struct oxnas_pcie {
struct regmap *sys_ctrl;
unsigned int outbound_offset;
unsigned int pcie_ctrl_offset;

struct phy *phy;
int haslink;
struct platform_device *pdev;
struct resource io;
@@ -406,52 +388,11 @@ static void oxnas_pcie_enable(struct device *dev, struct oxnas_pcie *pcie)
pci_common_init_dev(dev, &hw);
}

void oxnas_pcie_init_shared_hw(struct platform_device *pdev,
void __iomem *phybase,
struct regmap *sys_ctrl)
{
struct reset_control *rstc;
int ret;

/* generate clocks from HCSL buffers, shared parts */
regmap_write(sys_ctrl, SYS_CTRL_HCSL_CTRL_REGOFFSET, HCSL_BIAS_ON|HCSL_PCIE_EN);

/* Ensure PCIe PHY is properly reset */
rstc = reset_control_get(&pdev->dev, "phy");
if (IS_ERR(rstc)) {
ret = PTR_ERR(rstc);
} else {
ret = reset_control_reset(rstc);
reset_control_put(rstc);
}

if (ret) {
dev_err(&pdev->dev, "phy reset failed %d\n", ret);
return;
}

/* Enable PCIe Pre-Emphasis: What these value means? */
writel(ADDR_VAL(0x0014), phybase + PHY_ADDR);
writel(DATA_VAL(0xce10) | CAP_DATA, phybase + PHY_DATA);
writel(DATA_VAL(0xce10) | WRITE_EN, phybase + PHY_DATA);

writel(ADDR_VAL(0x2004), phybase + PHY_ADDR);
writel(DATA_VAL(0x82c7) | CAP_DATA, phybase + PHY_DATA);
writel(DATA_VAL(0x82c7) | WRITE_EN, phybase + PHY_DATA);
}

static int oxnas_pcie_shared_init(struct platform_device *pdev, struct regmap *sys_ctrl)
static int oxnas_pcie_shared_init(struct platform_device *pdev, struct oxnas_pcie *pcie)
{
if (++pcie_shared.refcount == 1) {
/* we are the first */
struct device_node *np = pdev->dev.of_node;
void __iomem *phy = of_iomap(np, 2);
if (!phy) {
--pcie_shared.refcount;
return -ENOMEM;
}
oxnas_pcie_init_shared_hw(pdev, phy, sys_ctrl);
iounmap(phy);
phy_init(pcie->phy);
phy_power_on(pcie->phy);
return 0;
} else {
return 0;
@@ -478,7 +419,6 @@ oxnas_pcie_map_registers(struct platform_device *pdev,
u32 outbound_ctrl_offset;
u32 pcie_ctrl_offset;

/* 2 is reserved for shared phy */
ret = of_address_to_resource(np, 0, &regs);
if (ret)
return -EINVAL;
@@ -493,6 +433,12 @@ oxnas_pcie_map_registers(struct platform_device *pdev,
if (!pcie->inbound)
return -ENOMEM;

pcie->phy = devm_of_phy_get(&pdev->dev, np, NULL);
if (IS_ERR(pcie->phy)) {
if (PTR_ERR(pcie->phy) == -EPROBE_DEFER)
return PTR_ERR(pcie->phy);
pcie->phy = NULL;
}

if (of_property_read_u32(np, "plxtech,pcie-outbound-offset",
&outbound_ctrl_offset))
@@ -589,6 +535,7 @@ static void oxnas_pcie_init_hw(struct platform_device *pdev,
mdelay(100);
}

/* ToDo: use phy power-on port... */
regmap_update_bits(pcie->sys_ctrl, SYS_CTRL_HCSL_CTRL_REGOFFSET,
BIT(pcie->hcsl_en), BIT(pcie->hcsl_en));

@@ -664,7 +611,7 @@ static int oxnas_pcie_probe(struct platform_device *pdev)
goto err_free_gpio;
}

ret = oxnas_pcie_shared_init(pdev, pcie->sys_ctrl);
ret = oxnas_pcie_shared_init(pdev, pcie);
if (ret)
goto err_free_gpio;

@@ -0,0 +1,150 @@
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2019 Daniel Golle <daniel@makrotopia.org>
*
*/

#include <dt-bindings/phy/phy.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/mfd/syscon.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/reset.h>

#define ADDR_VAL(val) ((val) & 0xFFFF)
#define DATA_VAL(val) ((val) & 0xFFFF)

#define SYS_CTRL_HCSL_CTRL_REGOFFSET 0x114

enum {
HCSL_BIAS_ON = BIT(0),
HCSL_PCIE_EN = BIT(1),
HCSL_PCIEA_EN = BIT(2),
HCSL_PCIEB_EN = BIT(3),
};

enum {
/* pcie phy reg offset */
PHY_ADDR = 0,
PHY_DATA = 4,
/* phy data reg bits */
READ_EN = BIT(16),
WRITE_EN = BIT(17),
CAP_DATA = BIT(18),
};

struct oxnas_pcie_phy {
struct device *dev;
void __iomem *membase;
const struct phy_ops *ops;
struct regmap *sys_ctrl;
};

static int oxnas_pcie_phy_init(struct phy *phy)
{
struct oxnas_pcie_phy *pciephy = phy_get_drvdata(phy);
struct reset_control *rstc;
int ret;

/* generate clocks from HCSL buffers, shared parts */
regmap_write(pciephy->sys_ctrl, SYS_CTRL_HCSL_CTRL_REGOFFSET, HCSL_BIAS_ON|HCSL_PCIE_EN);

/* Ensure PCIe PHY is properly reset */
rstc = reset_control_get(pciephy->dev, "phy");
if (IS_ERR(rstc)) {
ret = PTR_ERR(rstc);
} else {
ret = reset_control_reset(rstc);
reset_control_put(rstc);
}

if (ret) {
dev_err(pciephy->dev, "phy reset failed %d\n", ret);
return ret;
}

return 0;
}

static int oxnas_pcie_phy_power_on(struct phy *phy)
{
struct oxnas_pcie_phy *pciephy = phy_get_drvdata(phy);

/* Enable PCIe Pre-Emphasis: What these value means? */
writel(ADDR_VAL(0x0014), pciephy->membase + PHY_ADDR);
writel(DATA_VAL(0xce10) | CAP_DATA, pciephy->membase + PHY_DATA);
writel(DATA_VAL(0xce10) | WRITE_EN, pciephy->membase + PHY_DATA);

writel(ADDR_VAL(0x2004), pciephy->membase + PHY_ADDR);
writel(DATA_VAL(0x82c7) | CAP_DATA, pciephy->membase + PHY_DATA);
writel(DATA_VAL(0x82c7) | WRITE_EN, pciephy->membase + PHY_DATA);

return 0;
}

static const struct phy_ops ops = {
.init = oxnas_pcie_phy_init,
.power_on = oxnas_pcie_phy_power_on,
.owner = THIS_MODULE,
};

static int oxnas_pcie_phy_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct device_node *np = pdev->dev.of_node;
struct phy *generic_phy;
struct phy_provider *phy_provider;
struct oxnas_pcie_phy *pciephy;
struct regmap *sys_ctrl;
void __iomem *membase;

membase = of_iomap(np, 0);
if (IS_ERR(membase))
return PTR_ERR(membase);

sys_ctrl = syscon_regmap_lookup_by_compatible("oxsemi,ox820-sys-ctrl");
if (IS_ERR(sys_ctrl)) {
dev_err(dev, "Cannot find OX820 SYSCRTL\n");
return PTR_ERR(sys_ctrl);
}

pciephy = devm_kzalloc(dev, sizeof(*pciephy), GFP_KERNEL);
if (!pciephy)
return -ENOMEM;

pciephy->sys_ctrl = sys_ctrl;
pciephy->membase = membase;
pciephy->dev = dev;
pciephy->ops = &ops;

generic_phy = devm_phy_create(dev, dev->of_node, pciephy->ops);
if (IS_ERR(generic_phy)) {
dev_err(dev, "failed to create PHY\n");
return PTR_ERR(generic_phy);
}

phy_set_drvdata(generic_phy, pciephy);
phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);

return PTR_ERR_OR_ZERO(phy_provider);
}

static const struct of_device_id oxnas_pcie_phy_id_table[] = {
{ .compatible = "oxsemi,ox820-pcie-phy" },
{ },
};

static struct platform_driver oxnas_pcie_phy_driver = {
.probe = oxnas_pcie_phy_probe,
.driver = {
.name = "ox820-pcie-phy",
.of_match_table = oxnas_pcie_phy_id_table,
},
};

builtin_platform_driver(oxnas_pcie_phy_driver);
@@ -0,0 +1,44 @@
--- a/arch/arm/boot/dts/ox820.dtsi
+++ b/arch/arm/boot/dts/ox820.dtsi
@@ -246,6 +246,15 @@
};
};

+ pcie_phy: pcie-phy@a00000 {
+ compatible = "oxsemi,ox820-pcie-phy";
+ reg = <0xa00000 0x10>;
+ #phy-cells = <0>;
+ resets = <&reset RESET_PCIEPHY>;
+ reset-names = "phy";
+ status = "disabled";
+ };
+
sys: sys-ctrl@e00000 {
compatible = "oxsemi,ox820-sys-ctrl", "syscon", "simple-mfd";
reg = <0xe00000 0x200000>;
--- a/drivers/phy/Kconfig
+++ b/drivers/phy/Kconfig
@@ -26,6 +26,13 @@ config PHY_LPC18XX_USB_OTG
This driver is need for USB0 support on LPC18xx/43xx and takes
care of enabling and clock setup.

+config PHY_OXNAS
+ tristate "Oxford Semi. OX820 PCI-E PHY support"
+ depends on HAS_IOMEM && OF && (ARM || COMPILE_TEST)
+ select GENERIC_PHY
+ help
+ This option enables support for OXNAS OX820 SoC PCIE PHY.
+
config PHY_PISTACHIO_USB
tristate "IMG Pistachio USB2.0 PHY driver"
depends on MACH_PISTACHIO
--- a/drivers/phy/Makefile
+++ b/drivers/phy/Makefile
@@ -5,6 +5,7 @@

obj-$(CONFIG_GENERIC_PHY) += phy-core.o
obj-$(CONFIG_PHY_LPC18XX_USB_OTG) += phy-lpc18xx-usb-otg.o
+obj-$(CONFIG_PHY_OXNAS) += phy-oxnas-pcie.o
obj-$(CONFIG_PHY_XGENE) += phy-xgene.o
obj-$(CONFIG_PHY_PISTACHIO_USB) += phy-pistachio-usb.o
obj-$(CONFIG_ARCH_SUNXI) += allwinner/

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