linux/drivers/phy/broadcom/phy-bcm-cygnus-pcie.c

222 lines
5.1 KiB
C

/*
* Copyright (C) 2015 Broadcom Corporation
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation version 2.
*
* This program is distributed "as is" WITHOUT ANY WARRANTY of any
* kind, whether express or implied; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/phy/phy.h>
#include <linux/platform_device.h>
#define PCIE_CFG_OFFSET 0x00
#define PCIE1_PHY_IDDQ_SHIFT 10
#define PCIE0_PHY_IDDQ_SHIFT 2
enum cygnus_pcie_phy_id {
CYGNUS_PHY_PCIE0 = 0,
CYGNUS_PHY_PCIE1,
MAX_NUM_PHYS,
};
struct cygnus_pcie_phy_core;
/**
* struct cygnus_pcie_phy - Cygnus PCIe PHY device
* @core: pointer to the Cygnus PCIe PHY core control
* @id: internal ID to identify the Cygnus PCIe PHY
* @phy: pointer to the kernel PHY device
*/
struct cygnus_pcie_phy {
struct cygnus_pcie_phy_core *core;
enum cygnus_pcie_phy_id id;
struct phy *phy;
};
/**
* struct cygnus_pcie_phy_core - Cygnus PCIe PHY core control
* @dev: pointer to device
* @base: base register
* @lock: mutex to protect access to individual PHYs
* @phys: pointer to Cygnus PHY device
*/
struct cygnus_pcie_phy_core {
struct device *dev;
void __iomem *base;
struct mutex lock;
struct cygnus_pcie_phy phys[MAX_NUM_PHYS];
};
static int cygnus_pcie_power_config(struct cygnus_pcie_phy *phy, bool enable)
{
struct cygnus_pcie_phy_core *core = phy->core;
unsigned shift;
u32 val;
mutex_lock(&core->lock);
switch (phy->id) {
case CYGNUS_PHY_PCIE0:
shift = PCIE0_PHY_IDDQ_SHIFT;
break;
case CYGNUS_PHY_PCIE1:
shift = PCIE1_PHY_IDDQ_SHIFT;
break;
default:
mutex_unlock(&core->lock);
dev_err(core->dev, "PCIe PHY %d invalid\n", phy->id);
return -EINVAL;
}
if (enable) {
val = readl(core->base + PCIE_CFG_OFFSET);
val &= ~BIT(shift);
writel(val, core->base + PCIE_CFG_OFFSET);
/*
* Wait 50 ms for the PCIe Serdes to stabilize after the analog
* front end is brought up
*/
msleep(50);
} else {
val = readl(core->base + PCIE_CFG_OFFSET);
val |= BIT(shift);
writel(val, core->base + PCIE_CFG_OFFSET);
}
mutex_unlock(&core->lock);
dev_dbg(core->dev, "PCIe PHY %d %s\n", phy->id,
enable ? "enabled" : "disabled");
return 0;
}
static int cygnus_pcie_phy_power_on(struct phy *p)
{
struct cygnus_pcie_phy *phy = phy_get_drvdata(p);
return cygnus_pcie_power_config(phy, true);
}
static int cygnus_pcie_phy_power_off(struct phy *p)
{
struct cygnus_pcie_phy *phy = phy_get_drvdata(p);
return cygnus_pcie_power_config(phy, false);
}
static const struct phy_ops cygnus_pcie_phy_ops = {
.power_on = cygnus_pcie_phy_power_on,
.power_off = cygnus_pcie_phy_power_off,
.owner = THIS_MODULE,
};
static int cygnus_pcie_phy_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct device_node *node = dev->of_node, *child;
struct cygnus_pcie_phy_core *core;
struct phy_provider *provider;
struct resource *res;
unsigned cnt = 0;
int ret;
if (of_get_child_count(node) == 0) {
dev_err(dev, "PHY no child node\n");
return -ENODEV;
}
core = devm_kzalloc(dev, sizeof(*core), GFP_KERNEL);
if (!core)
return -ENOMEM;
core->dev = dev;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
core->base = devm_ioremap_resource(dev, res);
if (IS_ERR(core->base))
return PTR_ERR(core->base);
mutex_init(&core->lock);
for_each_available_child_of_node(node, child) {
unsigned int id;
struct cygnus_pcie_phy *p;
if (of_property_read_u32(child, "reg", &id)) {
dev_err(dev, "missing reg property for %s\n",
child->name);
ret = -EINVAL;
goto put_child;
}
if (id >= MAX_NUM_PHYS) {
dev_err(dev, "invalid PHY id: %u\n", id);
ret = -EINVAL;
goto put_child;
}
if (core->phys[id].phy) {
dev_err(dev, "duplicated PHY id: %u\n", id);
ret = -EINVAL;
goto put_child;
}
p = &core->phys[id];
p->phy = devm_phy_create(dev, child, &cygnus_pcie_phy_ops);
if (IS_ERR(p->phy)) {
dev_err(dev, "failed to create PHY\n");
ret = PTR_ERR(p->phy);
goto put_child;
}
p->core = core;
p->id = id;
phy_set_drvdata(p->phy, p);
cnt++;
}
dev_set_drvdata(dev, core);
provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
if (IS_ERR(provider)) {
dev_err(dev, "failed to register PHY provider\n");
return PTR_ERR(provider);
}
dev_dbg(dev, "registered %u PCIe PHY(s)\n", cnt);
return 0;
put_child:
of_node_put(child);
return ret;
}
static const struct of_device_id cygnus_pcie_phy_match_table[] = {
{ .compatible = "brcm,cygnus-pcie-phy" },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, cygnus_pcie_phy_match_table);
static struct platform_driver cygnus_pcie_phy_driver = {
.driver = {
.name = "cygnus-pcie-phy",
.of_match_table = cygnus_pcie_phy_match_table,
},
.probe = cygnus_pcie_phy_probe,
};
module_platform_driver(cygnus_pcie_phy_driver);
MODULE_AUTHOR("Ray Jui <rjui@broadcom.com>");
MODULE_DESCRIPTION("Broadcom Cygnus PCIe PHY driver");
MODULE_LICENSE("GPL v2");