diff options
Diffstat (limited to 'drivers/phy/broadcom/phy-bcm-sr-pcie.c')
-rw-r--r-- | drivers/phy/broadcom/phy-bcm-sr-pcie.c | 302 |
1 files changed, 302 insertions, 0 deletions
diff --git a/drivers/phy/broadcom/phy-bcm-sr-pcie.c b/drivers/phy/broadcom/phy-bcm-sr-pcie.c new file mode 100644 index 000000000..8a4aadf16 --- /dev/null +++ b/drivers/phy/broadcom/phy-bcm-sr-pcie.c @@ -0,0 +1,302 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2016-2018 Broadcom + */ + +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/mfd/syscon.h> +#include <linux/of.h> +#include <linux/phy/phy.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> + +/* we have up to 8 PAXB based RC. The 9th one is always PAXC */ +#define SR_NR_PCIE_PHYS 9 +#define SR_PAXC_PHY_IDX (SR_NR_PCIE_PHYS - 1) + +#define PCIE_PIPEMUX_CFG_OFFSET 0x10c +#define PCIE_PIPEMUX_SELECT_STRAP 0xf + +#define CDRU_STRAP_DATA_LSW_OFFSET 0x5c +#define PCIE_PIPEMUX_SHIFT 19 +#define PCIE_PIPEMUX_MASK 0xf + +#define MHB_MEM_PW_PAXC_OFFSET 0x1c0 +#define MHB_PWR_ARR_POWERON 0x8 +#define MHB_PWR_ARR_POWEROK 0x4 +#define MHB_PWR_POWERON 0x2 +#define MHB_PWR_POWEROK 0x1 +#define MHB_PWR_STATUS_MASK (MHB_PWR_ARR_POWERON | \ + MHB_PWR_ARR_POWEROK | \ + MHB_PWR_POWERON | \ + MHB_PWR_POWEROK) + +struct sr_pcie_phy_core; + +/** + * struct sr_pcie_phy - Stingray PCIe PHY + * + * @core: pointer to the Stingray PCIe PHY core control + * @index: PHY index + * @phy: pointer to the kernel PHY device + */ +struct sr_pcie_phy { + struct sr_pcie_phy_core *core; + unsigned int index; + struct phy *phy; +}; + +/** + * struct sr_pcie_phy_core - Stingray PCIe PHY core control + * + * @dev: pointer to device + * @base: base register of PCIe SS + * @cdru: regmap to the CDRU device + * @mhb: regmap to the MHB device + * @pipemux: pipemuex strap + * @phys: array of PCIe PHYs + */ +struct sr_pcie_phy_core { + struct device *dev; + void __iomem *base; + struct regmap *cdru; + struct regmap *mhb; + u32 pipemux; + struct sr_pcie_phy phys[SR_NR_PCIE_PHYS]; +}; + +/* + * PCIe PIPEMUX lookup table + * + * Each array index represents a PIPEMUX strap setting + * The array element represents a bitmap where a set bit means the PCIe + * core and associated serdes has been enabled as RC and is available for use + */ +static const u8 pipemux_table[] = { + /* PIPEMUX = 0, EP 1x16 */ + 0x00, + /* PIPEMUX = 1, EP 1x8 + RC 1x8, core 7 */ + 0x80, + /* PIPEMUX = 2, EP 4x4 */ + 0x00, + /* PIPEMUX = 3, RC 2x8, cores 0, 7 */ + 0x81, + /* PIPEMUX = 4, RC 4x4, cores 0, 1, 6, 7 */ + 0xc3, + /* PIPEMUX = 5, RC 8x2, all 8 cores */ + 0xff, + /* PIPEMUX = 6, RC 3x4 + 2x2, cores 0, 2, 3, 6, 7 */ + 0xcd, + /* PIPEMUX = 7, RC 1x4 + 6x2, cores 0, 2, 3, 4, 5, 6, 7 */ + 0xfd, + /* PIPEMUX = 8, EP 1x8 + RC 4x2, cores 4, 5, 6, 7 */ + 0xf0, + /* PIPEMUX = 9, EP 1x8 + RC 2x4, cores 6, 7 */ + 0xc0, + /* PIPEMUX = 10, EP 2x4 + RC 2x4, cores 1, 6 */ + 0x42, + /* PIPEMUX = 11, EP 2x4 + RC 4x2, cores 2, 3, 4, 5 */ + 0x3c, + /* PIPEMUX = 12, EP 1x4 + RC 6x2, cores 2, 3, 4, 5, 6, 7 */ + 0xfc, + /* PIPEMUX = 13, RC 2x4 + RC 1x4 + 2x2, cores 2, 3, 6 */ + 0x4c, +}; + +/* + * Return true if the strap setting is valid + */ +static bool pipemux_strap_is_valid(u32 pipemux) +{ + return !!(pipemux < ARRAY_SIZE(pipemux_table)); +} + +/* + * Read the PCIe PIPEMUX from strap + */ +static u32 pipemux_strap_read(struct sr_pcie_phy_core *core) +{ + u32 pipemux; + + /* + * Read PIPEMUX configuration register to determine the pipemux setting + * + * In the case when the value indicates using HW strap, fall back to + * use HW strap + */ + pipemux = readl(core->base + PCIE_PIPEMUX_CFG_OFFSET); + pipemux &= PCIE_PIPEMUX_MASK; + if (pipemux == PCIE_PIPEMUX_SELECT_STRAP) { + regmap_read(core->cdru, CDRU_STRAP_DATA_LSW_OFFSET, &pipemux); + pipemux >>= PCIE_PIPEMUX_SHIFT; + pipemux &= PCIE_PIPEMUX_MASK; + } + + return pipemux; +} + +/* + * Given a PIPEMUX strap and PCIe core index, this function returns true if the + * PCIe core needs to be enabled + */ +static bool pcie_core_is_for_rc(struct sr_pcie_phy *phy) +{ + struct sr_pcie_phy_core *core = phy->core; + unsigned int core_idx = phy->index; + + return !!((pipemux_table[core->pipemux] >> core_idx) & 0x1); +} + +static int sr_pcie_phy_init(struct phy *p) +{ + struct sr_pcie_phy *phy = phy_get_drvdata(p); + + /* + * Check whether this PHY is for root complex or not. If yes, return + * zero so the host driver can proceed to enumeration. If not, return + * an error and that will force the host driver to bail out + */ + if (pcie_core_is_for_rc(phy)) + return 0; + + return -ENODEV; +} + +static int sr_paxc_phy_init(struct phy *p) +{ + struct sr_pcie_phy *phy = phy_get_drvdata(p); + struct sr_pcie_phy_core *core = phy->core; + unsigned int core_idx = phy->index; + u32 val; + + if (core_idx != SR_PAXC_PHY_IDX) + return -EINVAL; + + regmap_read(core->mhb, MHB_MEM_PW_PAXC_OFFSET, &val); + if ((val & MHB_PWR_STATUS_MASK) != MHB_PWR_STATUS_MASK) { + dev_err(core->dev, "PAXC is not powered up\n"); + return -ENODEV; + } + + return 0; +} + +static const struct phy_ops sr_pcie_phy_ops = { + .init = sr_pcie_phy_init, + .owner = THIS_MODULE, +}; + +static const struct phy_ops sr_paxc_phy_ops = { + .init = sr_paxc_phy_init, + .owner = THIS_MODULE, +}; + +static struct phy *sr_pcie_phy_xlate(struct device *dev, + struct of_phandle_args *args) +{ + struct sr_pcie_phy_core *core; + int phy_idx; + + core = dev_get_drvdata(dev); + if (!core) + return ERR_PTR(-EINVAL); + + phy_idx = args->args[0]; + + if (WARN_ON(phy_idx >= SR_NR_PCIE_PHYS)) + return ERR_PTR(-ENODEV); + + return core->phys[phy_idx].phy; +} + +static int sr_pcie_phy_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct device_node *node = dev->of_node; + struct sr_pcie_phy_core *core; + struct phy_provider *provider; + unsigned int phy_idx = 0; + + core = devm_kzalloc(dev, sizeof(*core), GFP_KERNEL); + if (!core) + return -ENOMEM; + + core->dev = dev; + core->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(core->base)) + return PTR_ERR(core->base); + + core->cdru = syscon_regmap_lookup_by_phandle(node, "brcm,sr-cdru"); + if (IS_ERR(core->cdru)) { + dev_err(core->dev, "unable to find CDRU device\n"); + return PTR_ERR(core->cdru); + } + + core->mhb = syscon_regmap_lookup_by_phandle(node, "brcm,sr-mhb"); + if (IS_ERR(core->mhb)) { + dev_err(core->dev, "unable to find MHB device\n"); + return PTR_ERR(core->mhb); + } + + /* read the PCIe PIPEMUX strap setting */ + core->pipemux = pipemux_strap_read(core); + if (!pipemux_strap_is_valid(core->pipemux)) { + dev_err(core->dev, "invalid PCIe PIPEMUX strap %u\n", + core->pipemux); + return -EIO; + } + + for (phy_idx = 0; phy_idx < SR_NR_PCIE_PHYS; phy_idx++) { + struct sr_pcie_phy *p = &core->phys[phy_idx]; + const struct phy_ops *ops; + + if (phy_idx == SR_PAXC_PHY_IDX) + ops = &sr_paxc_phy_ops; + else + ops = &sr_pcie_phy_ops; + + p->phy = devm_phy_create(dev, NULL, ops); + if (IS_ERR(p->phy)) { + dev_err(dev, "failed to create PCIe PHY\n"); + return PTR_ERR(p->phy); + } + + p->core = core; + p->index = phy_idx; + phy_set_drvdata(p->phy, p); + } + + dev_set_drvdata(dev, core); + + provider = devm_of_phy_provider_register(dev, sr_pcie_phy_xlate); + if (IS_ERR(provider)) { + dev_err(dev, "failed to register PHY provider\n"); + return PTR_ERR(provider); + } + + dev_info(dev, "Stingray PCIe PHY driver initialized\n"); + + return 0; +} + +static const struct of_device_id sr_pcie_phy_match_table[] = { + { .compatible = "brcm,sr-pcie-phy" }, + { } +}; +MODULE_DEVICE_TABLE(of, sr_pcie_phy_match_table); + +static struct platform_driver sr_pcie_phy_driver = { + .driver = { + .name = "sr-pcie-phy", + .of_match_table = sr_pcie_phy_match_table, + }, + .probe = sr_pcie_phy_probe, +}; +module_platform_driver(sr_pcie_phy_driver); + +MODULE_AUTHOR("Ray Jui <ray.jui@broadcom.com>"); +MODULE_DESCRIPTION("Broadcom Stingray PCIe PHY driver"); +MODULE_LICENSE("GPL v2"); |