| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * PCIe host controller driver for Amlogic MESON SoCs |
| * |
| * Copyright (c) 2018 Amlogic, inc. |
| * Author: Yue Wang <yue.wang@amlogic.com> |
| */ |
| |
| #include <linux/clk.h> |
| #include <linux/delay.h> |
| #include <linux/gpio/consumer.h> |
| #include <linux/of_device.h> |
| #include <linux/of_gpio.h> |
| #include <linux/pci.h> |
| #include <linux/platform_device.h> |
| #include <linux/reset.h> |
| #include <linux/resource.h> |
| #include <linux/types.h> |
| #include <linux/phy/phy.h> |
| #include <linux/module.h> |
| |
| #include "pcie-designware.h" |
| |
| #define to_meson_pcie(x) dev_get_drvdata((x)->dev) |
| |
| #define PCIE_CAP_MAX_PAYLOAD_SIZE(x) ((x) << 5) |
| #define PCIE_CAP_MAX_READ_REQ_SIZE(x) ((x) << 12) |
| |
| /* PCIe specific config registers */ |
| #define PCIE_CFG0 0x0 |
| #define APP_LTSSM_ENABLE BIT(7) |
| |
| #define PCIE_CFG_STATUS12 0x30 |
| #define IS_SMLH_LINK_UP(x) ((x) & (1 << 6)) |
| #define IS_RDLH_LINK_UP(x) ((x) & (1 << 16)) |
| #define IS_LTSSM_UP(x) ((((x) >> 10) & 0x1f) == 0x11) |
| |
| #define PCIE_CFG_STATUS17 0x44 |
| #define PM_CURRENT_STATE(x) (((x) >> 7) & 0x1) |
| |
| #define WAIT_LINKUP_TIMEOUT 4000 |
| #define PORT_CLK_RATE 100000000UL |
| #define MAX_PAYLOAD_SIZE 256 |
| #define MAX_READ_REQ_SIZE 256 |
| #define PCIE_RESET_DELAY 500 |
| #define PCIE_SHARED_RESET 1 |
| #define PCIE_NORMAL_RESET 0 |
| |
| enum pcie_data_rate { |
| PCIE_GEN1, |
| PCIE_GEN2, |
| PCIE_GEN3, |
| PCIE_GEN4 |
| }; |
| |
| struct meson_pcie_clk_res { |
| struct clk *clk; |
| struct clk *port_clk; |
| struct clk *general_clk; |
| }; |
| |
| struct meson_pcie_rc_reset { |
| struct reset_control *port; |
| struct reset_control *apb; |
| }; |
| |
| struct meson_pcie { |
| struct dw_pcie pci; |
| void __iomem *cfg_base; |
| struct meson_pcie_clk_res clk_res; |
| struct meson_pcie_rc_reset mrst; |
| struct gpio_desc *reset_gpio; |
| struct phy *phy; |
| }; |
| |
| static struct reset_control *meson_pcie_get_reset(struct meson_pcie *mp, |
| const char *id, |
| u32 reset_type) |
| { |
| struct device *dev = mp->pci.dev; |
| struct reset_control *reset; |
| |
| if (reset_type == PCIE_SHARED_RESET) |
| reset = devm_reset_control_get_shared(dev, id); |
| else |
| reset = devm_reset_control_get(dev, id); |
| |
| return reset; |
| } |
| |
| static int meson_pcie_get_resets(struct meson_pcie *mp) |
| { |
| struct meson_pcie_rc_reset *mrst = &mp->mrst; |
| |
| mrst->port = meson_pcie_get_reset(mp, "port", PCIE_NORMAL_RESET); |
| if (IS_ERR(mrst->port)) |
| return PTR_ERR(mrst->port); |
| reset_control_deassert(mrst->port); |
| |
| mrst->apb = meson_pcie_get_reset(mp, "apb", PCIE_SHARED_RESET); |
| if (IS_ERR(mrst->apb)) |
| return PTR_ERR(mrst->apb); |
| reset_control_deassert(mrst->apb); |
| |
| return 0; |
| } |
| |
| static int meson_pcie_get_mems(struct platform_device *pdev, |
| struct meson_pcie *mp) |
| { |
| struct dw_pcie *pci = &mp->pci; |
| |
| pci->dbi_base = devm_platform_ioremap_resource_byname(pdev, "elbi"); |
| if (IS_ERR(pci->dbi_base)) |
| return PTR_ERR(pci->dbi_base); |
| |
| mp->cfg_base = devm_platform_ioremap_resource_byname(pdev, "cfg"); |
| if (IS_ERR(mp->cfg_base)) |
| return PTR_ERR(mp->cfg_base); |
| |
| return 0; |
| } |
| |
| static int meson_pcie_power_on(struct meson_pcie *mp) |
| { |
| int ret = 0; |
| |
| ret = phy_init(mp->phy); |
| if (ret) |
| return ret; |
| |
| ret = phy_power_on(mp->phy); |
| if (ret) { |
| phy_exit(mp->phy); |
| return ret; |
| } |
| |
| return 0; |
| } |
| |
| static void meson_pcie_power_off(struct meson_pcie *mp) |
| { |
| phy_power_off(mp->phy); |
| phy_exit(mp->phy); |
| } |
| |
| static int meson_pcie_reset(struct meson_pcie *mp) |
| { |
| struct meson_pcie_rc_reset *mrst = &mp->mrst; |
| int ret = 0; |
| |
| ret = phy_reset(mp->phy); |
| if (ret) |
| return ret; |
| |
| reset_control_assert(mrst->port); |
| reset_control_assert(mrst->apb); |
| udelay(PCIE_RESET_DELAY); |
| reset_control_deassert(mrst->port); |
| reset_control_deassert(mrst->apb); |
| udelay(PCIE_RESET_DELAY); |
| |
| return 0; |
| } |
| |
| static inline struct clk *meson_pcie_probe_clock(struct device *dev, |
| const char *id, u64 rate) |
| { |
| struct clk *clk; |
| int ret; |
| |
| clk = devm_clk_get(dev, id); |
| if (IS_ERR(clk)) |
| return clk; |
| |
| if (rate) { |
| ret = clk_set_rate(clk, rate); |
| if (ret) { |
| dev_err(dev, "set clk rate failed, ret = %d\n", ret); |
| return ERR_PTR(ret); |
| } |
| } |
| |
| ret = clk_prepare_enable(clk); |
| if (ret) { |
| dev_err(dev, "couldn't enable clk\n"); |
| return ERR_PTR(ret); |
| } |
| |
| devm_add_action_or_reset(dev, |
| (void (*) (void *))clk_disable_unprepare, |
| clk); |
| |
| return clk; |
| } |
| |
| static int meson_pcie_probe_clocks(struct meson_pcie *mp) |
| { |
| struct device *dev = mp->pci.dev; |
| struct meson_pcie_clk_res *res = &mp->clk_res; |
| |
| res->port_clk = meson_pcie_probe_clock(dev, "port", PORT_CLK_RATE); |
| if (IS_ERR(res->port_clk)) |
| return PTR_ERR(res->port_clk); |
| |
| res->general_clk = meson_pcie_probe_clock(dev, "general", 0); |
| if (IS_ERR(res->general_clk)) |
| return PTR_ERR(res->general_clk); |
| |
| res->clk = meson_pcie_probe_clock(dev, "pclk", 0); |
| if (IS_ERR(res->clk)) |
| return PTR_ERR(res->clk); |
| |
| return 0; |
| } |
| |
| static inline u32 meson_cfg_readl(struct meson_pcie *mp, u32 reg) |
| { |
| return readl(mp->cfg_base + reg); |
| } |
| |
| static inline void meson_cfg_writel(struct meson_pcie *mp, u32 val, u32 reg) |
| { |
| writel(val, mp->cfg_base + reg); |
| } |
| |
| static void meson_pcie_assert_reset(struct meson_pcie *mp) |
| { |
| gpiod_set_value_cansleep(mp->reset_gpio, 1); |
| udelay(500); |
| gpiod_set_value_cansleep(mp->reset_gpio, 0); |
| } |
| |
| static void meson_pcie_ltssm_enable(struct meson_pcie *mp) |
| { |
| u32 val; |
| |
| val = meson_cfg_readl(mp, PCIE_CFG0); |
| val |= APP_LTSSM_ENABLE; |
| meson_cfg_writel(mp, val, PCIE_CFG0); |
| } |
| |
| static int meson_size_to_payload(struct meson_pcie *mp, int size) |
| { |
| struct device *dev = mp->pci.dev; |
| |
| /* |
| * dwc supports 2^(val+7) payload size, which val is 0~5 default to 1. |
| * So if input size is not 2^order alignment or less than 2^7 or bigger |
| * than 2^12, just set to default size 2^(1+7). |
| */ |
| if (!is_power_of_2(size) || size < 128 || size > 4096) { |
| dev_warn(dev, "payload size %d, set to default 256\n", size); |
| return 1; |
| } |
| |
| return fls(size) - 8; |
| } |
| |
| static void meson_set_max_payload(struct meson_pcie *mp, int size) |
| { |
| struct dw_pcie *pci = &mp->pci; |
| u32 val; |
| u16 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP); |
| int max_payload_size = meson_size_to_payload(mp, size); |
| |
| val = dw_pcie_readl_dbi(pci, offset + PCI_EXP_DEVCTL); |
| val &= ~PCI_EXP_DEVCTL_PAYLOAD; |
| dw_pcie_writel_dbi(pci, offset + PCI_EXP_DEVCTL, val); |
| |
| val = dw_pcie_readl_dbi(pci, offset + PCI_EXP_DEVCTL); |
| val |= PCIE_CAP_MAX_PAYLOAD_SIZE(max_payload_size); |
| dw_pcie_writel_dbi(pci, offset + PCI_EXP_DEVCTL, val); |
| } |
| |
| static void meson_set_max_rd_req_size(struct meson_pcie *mp, int size) |
| { |
| struct dw_pcie *pci = &mp->pci; |
| u32 val; |
| u16 offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP); |
| int max_rd_req_size = meson_size_to_payload(mp, size); |
| |
| val = dw_pcie_readl_dbi(pci, offset + PCI_EXP_DEVCTL); |
| val &= ~PCI_EXP_DEVCTL_READRQ; |
| dw_pcie_writel_dbi(pci, offset + PCI_EXP_DEVCTL, val); |
| |
| val = dw_pcie_readl_dbi(pci, offset + PCI_EXP_DEVCTL); |
| val |= PCIE_CAP_MAX_READ_REQ_SIZE(max_rd_req_size); |
| dw_pcie_writel_dbi(pci, offset + PCI_EXP_DEVCTL, val); |
| } |
| |
| static int meson_pcie_start_link(struct dw_pcie *pci) |
| { |
| struct meson_pcie *mp = to_meson_pcie(pci); |
| |
| meson_pcie_ltssm_enable(mp); |
| meson_pcie_assert_reset(mp); |
| |
| return 0; |
| } |
| |
| static int meson_pcie_rd_own_conf(struct pci_bus *bus, u32 devfn, |
| int where, int size, u32 *val) |
| { |
| int ret; |
| |
| ret = pci_generic_config_read(bus, devfn, where, size, val); |
| if (ret != PCIBIOS_SUCCESSFUL) |
| return ret; |
| |
| /* |
| * There is a bug in the MESON AXG PCIe controller whereby software |
| * cannot program the PCI_CLASS_DEVICE register, so we must fabricate |
| * the return value in the config accessors. |
| */ |
| if (where == PCI_CLASS_REVISION && size == 4) |
| *val = (PCI_CLASS_BRIDGE_PCI << 16) | (*val & 0xffff); |
| else if (where == PCI_CLASS_DEVICE && size == 2) |
| *val = PCI_CLASS_BRIDGE_PCI; |
| else if (where == PCI_CLASS_DEVICE && size == 1) |
| *val = PCI_CLASS_BRIDGE_PCI & 0xff; |
| else if (where == PCI_CLASS_DEVICE + 1 && size == 1) |
| *val = (PCI_CLASS_BRIDGE_PCI >> 8) & 0xff; |
| |
| return PCIBIOS_SUCCESSFUL; |
| } |
| |
| static struct pci_ops meson_pci_ops = { |
| .map_bus = dw_pcie_own_conf_map_bus, |
| .read = meson_pcie_rd_own_conf, |
| .write = pci_generic_config_write, |
| }; |
| |
| static int meson_pcie_link_up(struct dw_pcie *pci) |
| { |
| struct meson_pcie *mp = to_meson_pcie(pci); |
| struct device *dev = pci->dev; |
| u32 speed_okay = 0; |
| u32 cnt = 0; |
| u32 state12, state17, smlh_up, ltssm_up, rdlh_up; |
| |
| do { |
| state12 = meson_cfg_readl(mp, PCIE_CFG_STATUS12); |
| state17 = meson_cfg_readl(mp, PCIE_CFG_STATUS17); |
| smlh_up = IS_SMLH_LINK_UP(state12); |
| rdlh_up = IS_RDLH_LINK_UP(state12); |
| ltssm_up = IS_LTSSM_UP(state12); |
| |
| if (PM_CURRENT_STATE(state17) < PCIE_GEN3) |
| speed_okay = 1; |
| |
| if (smlh_up) |
| dev_dbg(dev, "smlh_link_up is on\n"); |
| if (rdlh_up) |
| dev_dbg(dev, "rdlh_link_up is on\n"); |
| if (ltssm_up) |
| dev_dbg(dev, "ltssm_up is on\n"); |
| if (speed_okay) |
| dev_dbg(dev, "speed_okay\n"); |
| |
| if (smlh_up && rdlh_up && ltssm_up && speed_okay) |
| return 1; |
| |
| cnt++; |
| |
| udelay(10); |
| } while (cnt < WAIT_LINKUP_TIMEOUT); |
| |
| dev_err(dev, "error: wait linkup timeout\n"); |
| return 0; |
| } |
| |
| static int meson_pcie_host_init(struct pcie_port *pp) |
| { |
| struct dw_pcie *pci = to_dw_pcie_from_pp(pp); |
| struct meson_pcie *mp = to_meson_pcie(pci); |
| |
| pp->bridge->ops = &meson_pci_ops; |
| |
| meson_set_max_payload(mp, MAX_PAYLOAD_SIZE); |
| meson_set_max_rd_req_size(mp, MAX_READ_REQ_SIZE); |
| |
| return 0; |
| } |
| |
| static const struct dw_pcie_host_ops meson_pcie_host_ops = { |
| .host_init = meson_pcie_host_init, |
| }; |
| |
| static const struct dw_pcie_ops dw_pcie_ops = { |
| .link_up = meson_pcie_link_up, |
| .start_link = meson_pcie_start_link, |
| }; |
| |
| static int meson_pcie_probe(struct platform_device *pdev) |
| { |
| struct device *dev = &pdev->dev; |
| struct dw_pcie *pci; |
| struct meson_pcie *mp; |
| int ret; |
| |
| mp = devm_kzalloc(dev, sizeof(*mp), GFP_KERNEL); |
| if (!mp) |
| return -ENOMEM; |
| |
| pci = &mp->pci; |
| pci->dev = dev; |
| pci->ops = &dw_pcie_ops; |
| pci->pp.ops = &meson_pcie_host_ops; |
| pci->num_lanes = 1; |
| |
| mp->phy = devm_phy_get(dev, "pcie"); |
| if (IS_ERR(mp->phy)) { |
| dev_err(dev, "get phy failed, %ld\n", PTR_ERR(mp->phy)); |
| return PTR_ERR(mp->phy); |
| } |
| |
| mp->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW); |
| if (IS_ERR(mp->reset_gpio)) { |
| dev_err(dev, "get reset gpio failed\n"); |
| return PTR_ERR(mp->reset_gpio); |
| } |
| |
| ret = meson_pcie_get_resets(mp); |
| if (ret) { |
| dev_err(dev, "get reset resource failed, %d\n", ret); |
| return ret; |
| } |
| |
| ret = meson_pcie_get_mems(pdev, mp); |
| if (ret) { |
| dev_err(dev, "get memory resource failed, %d\n", ret); |
| return ret; |
| } |
| |
| ret = meson_pcie_power_on(mp); |
| if (ret) { |
| dev_err(dev, "phy power on failed, %d\n", ret); |
| return ret; |
| } |
| |
| ret = meson_pcie_reset(mp); |
| if (ret) { |
| dev_err(dev, "reset failed, %d\n", ret); |
| goto err_phy; |
| } |
| |
| ret = meson_pcie_probe_clocks(mp); |
| if (ret) { |
| dev_err(dev, "init clock resources failed, %d\n", ret); |
| goto err_phy; |
| } |
| |
| platform_set_drvdata(pdev, mp); |
| |
| ret = dw_pcie_host_init(&pci->pp); |
| if (ret < 0) { |
| dev_err(dev, "Add PCIe port failed, %d\n", ret); |
| goto err_phy; |
| } |
| |
| return 0; |
| |
| err_phy: |
| meson_pcie_power_off(mp); |
| return ret; |
| } |
| |
| static const struct of_device_id meson_pcie_of_match[] = { |
| { |
| .compatible = "amlogic,axg-pcie", |
| }, |
| { |
| .compatible = "amlogic,g12a-pcie", |
| }, |
| {}, |
| }; |
| MODULE_DEVICE_TABLE(of, meson_pcie_of_match); |
| |
| static struct platform_driver meson_pcie_driver = { |
| .probe = meson_pcie_probe, |
| .driver = { |
| .name = "meson-pcie", |
| .of_match_table = meson_pcie_of_match, |
| }, |
| }; |
| |
| module_platform_driver(meson_pcie_driver); |
| |
| MODULE_AUTHOR("Yue Wang <yue.wang@amlogic.com>"); |
| MODULE_DESCRIPTION("Amlogic PCIe Controller driver"); |
| MODULE_LICENSE("GPL v2"); |