diff options
Diffstat (limited to 'drivers/phy/phy-bcm-cygnus-pcie.c')
| -rw-r--r-- | drivers/phy/phy-bcm-cygnus-pcie.c | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/drivers/phy/phy-bcm-cygnus-pcie.c b/drivers/phy/phy-bcm-cygnus-pcie.c new file mode 100644 index 000000000000..7ad72b7d2b98 --- /dev/null +++ b/drivers/phy/phy-bcm-cygnus-pcie.c @@ -0,0 +1,213 @@ +/* + * 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 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; + + 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); + return -EINVAL; + } + + if (id >= MAX_NUM_PHYS) { + dev_err(dev, "invalid PHY id: %u\n", id); + return -EINVAL; + } + + if (core->phys[id].phy) { + dev_err(dev, "duplicated PHY id: %u\n", id); + return -EINVAL; + } + + 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"); + return PTR_ERR(p->phy); + } + + 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; +} + +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"); |