linux/drivers/pci/controller/dwc/pcie-armada8k.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * PCIe host controller driver for Marvell Armada-8K SoCs
   4 *
   5 * Armada-8K PCIe Glue Layer Source Code
   6 *
   7 * Copyright (C) 2016 Marvell Technology Group Ltd.
   8 *
   9 * Author: Yehuda Yitshak <yehuday@marvell.com>
  10 * Author: Shadi Ammouri <shadi@marvell.com>
  11 */
  12
  13#include <linux/clk.h>
  14#include <linux/delay.h>
  15#include <linux/interrupt.h>
  16#include <linux/kernel.h>
  17#include <linux/init.h>
  18#include <linux/of.h>
  19#include <linux/pci.h>
  20#include <linux/phy/phy.h>
  21#include <linux/platform_device.h>
  22#include <linux/resource.h>
  23#include <linux/of_pci.h>
  24#include <linux/of_irq.h>
  25
  26#include "pcie-designware.h"
  27
  28#define ARMADA8K_PCIE_MAX_LANES PCIE_LNK_X4
  29
  30struct armada8k_pcie {
  31        struct dw_pcie *pci;
  32        struct clk *clk;
  33        struct clk *clk_reg;
  34        struct phy *phy[ARMADA8K_PCIE_MAX_LANES];
  35        unsigned int phy_count;
  36};
  37
  38#define PCIE_VENDOR_REGS_OFFSET         0x8000
  39
  40#define PCIE_GLOBAL_CONTROL_REG         (PCIE_VENDOR_REGS_OFFSET + 0x0)
  41#define PCIE_APP_LTSSM_EN               BIT(2)
  42#define PCIE_DEVICE_TYPE_SHIFT          4
  43#define PCIE_DEVICE_TYPE_MASK           0xF
  44#define PCIE_DEVICE_TYPE_RC             0x4 /* Root complex */
  45
  46#define PCIE_GLOBAL_STATUS_REG          (PCIE_VENDOR_REGS_OFFSET + 0x8)
  47#define PCIE_GLB_STS_RDLH_LINK_UP       BIT(1)
  48#define PCIE_GLB_STS_PHY_LINK_UP        BIT(9)
  49
  50#define PCIE_GLOBAL_INT_CAUSE1_REG      (PCIE_VENDOR_REGS_OFFSET + 0x1C)
  51#define PCIE_GLOBAL_INT_MASK1_REG       (PCIE_VENDOR_REGS_OFFSET + 0x20)
  52#define PCIE_INT_A_ASSERT_MASK          BIT(9)
  53#define PCIE_INT_B_ASSERT_MASK          BIT(10)
  54#define PCIE_INT_C_ASSERT_MASK          BIT(11)
  55#define PCIE_INT_D_ASSERT_MASK          BIT(12)
  56
  57#define PCIE_ARCACHE_TRC_REG            (PCIE_VENDOR_REGS_OFFSET + 0x50)
  58#define PCIE_AWCACHE_TRC_REG            (PCIE_VENDOR_REGS_OFFSET + 0x54)
  59#define PCIE_ARUSER_REG                 (PCIE_VENDOR_REGS_OFFSET + 0x5C)
  60#define PCIE_AWUSER_REG                 (PCIE_VENDOR_REGS_OFFSET + 0x60)
  61/*
  62 * AR/AW Cache defaults: Normal memory, Write-Back, Read / Write
  63 * allocate
  64 */
  65#define ARCACHE_DEFAULT_VALUE           0x3511
  66#define AWCACHE_DEFAULT_VALUE           0x5311
  67
  68#define DOMAIN_OUTER_SHAREABLE          0x2
  69#define AX_USER_DOMAIN_MASK             0x3
  70#define AX_USER_DOMAIN_SHIFT            4
  71
  72#define to_armada8k_pcie(x)     dev_get_drvdata((x)->dev)
  73
  74static void armada8k_pcie_disable_phys(struct armada8k_pcie *pcie)
  75{
  76        int i;
  77
  78        for (i = 0; i < ARMADA8K_PCIE_MAX_LANES; i++) {
  79                phy_power_off(pcie->phy[i]);
  80                phy_exit(pcie->phy[i]);
  81        }
  82}
  83
  84static int armada8k_pcie_enable_phys(struct armada8k_pcie *pcie)
  85{
  86        int ret;
  87        int i;
  88
  89        for (i = 0; i < ARMADA8K_PCIE_MAX_LANES; i++) {
  90                ret = phy_init(pcie->phy[i]);
  91                if (ret)
  92                        return ret;
  93
  94                ret = phy_set_mode_ext(pcie->phy[i], PHY_MODE_PCIE,
  95                                       pcie->phy_count);
  96                if (ret) {
  97                        phy_exit(pcie->phy[i]);
  98                        return ret;
  99                }
 100
 101                ret = phy_power_on(pcie->phy[i]);
 102                if (ret) {
 103                        phy_exit(pcie->phy[i]);
 104                        return ret;
 105                }
 106        }
 107
 108        return 0;
 109}
 110
 111static int armada8k_pcie_setup_phys(struct armada8k_pcie *pcie)
 112{
 113        struct dw_pcie *pci = pcie->pci;
 114        struct device *dev = pci->dev;
 115        struct device_node *node = dev->of_node;
 116        int ret = 0;
 117        int i;
 118
 119        for (i = 0; i < ARMADA8K_PCIE_MAX_LANES; i++) {
 120                pcie->phy[i] = devm_of_phy_get_by_index(dev, node, i);
 121                if (IS_ERR(pcie->phy[i])) {
 122                        if (PTR_ERR(pcie->phy[i]) != -ENODEV)
 123                                return PTR_ERR(pcie->phy[i]);
 124
 125                        pcie->phy[i] = NULL;
 126                        continue;
 127                }
 128
 129                pcie->phy_count++;
 130        }
 131
 132        /* Old bindings miss the PHY handle, so just warn if there is no PHY */
 133        if (!pcie->phy_count)
 134                dev_warn(dev, "No available PHY\n");
 135
 136        ret = armada8k_pcie_enable_phys(pcie);
 137        if (ret)
 138                dev_err(dev, "Failed to initialize PHY(s) (%d)\n", ret);
 139
 140        return ret;
 141}
 142
 143static int armada8k_pcie_link_up(struct dw_pcie *pci)
 144{
 145        u32 reg;
 146        u32 mask = PCIE_GLB_STS_RDLH_LINK_UP | PCIE_GLB_STS_PHY_LINK_UP;
 147
 148        reg = dw_pcie_readl_dbi(pci, PCIE_GLOBAL_STATUS_REG);
 149
 150        if ((reg & mask) == mask)
 151                return 1;
 152
 153        dev_dbg(pci->dev, "No link detected (Global-Status: 0x%08x).\n", reg);
 154        return 0;
 155}
 156
 157static void armada8k_pcie_establish_link(struct armada8k_pcie *pcie)
 158{
 159        struct dw_pcie *pci = pcie->pci;
 160        u32 reg;
 161
 162        if (!dw_pcie_link_up(pci)) {
 163                /* Disable LTSSM state machine to enable configuration */
 164                reg = dw_pcie_readl_dbi(pci, PCIE_GLOBAL_CONTROL_REG);
 165                reg &= ~(PCIE_APP_LTSSM_EN);
 166                dw_pcie_writel_dbi(pci, PCIE_GLOBAL_CONTROL_REG, reg);
 167        }
 168
 169        /* Set the device to root complex mode */
 170        reg = dw_pcie_readl_dbi(pci, PCIE_GLOBAL_CONTROL_REG);
 171        reg &= ~(PCIE_DEVICE_TYPE_MASK << PCIE_DEVICE_TYPE_SHIFT);
 172        reg |= PCIE_DEVICE_TYPE_RC << PCIE_DEVICE_TYPE_SHIFT;
 173        dw_pcie_writel_dbi(pci, PCIE_GLOBAL_CONTROL_REG, reg);
 174
 175        /* Set the PCIe master AxCache attributes */
 176        dw_pcie_writel_dbi(pci, PCIE_ARCACHE_TRC_REG, ARCACHE_DEFAULT_VALUE);
 177        dw_pcie_writel_dbi(pci, PCIE_AWCACHE_TRC_REG, AWCACHE_DEFAULT_VALUE);
 178
 179        /* Set the PCIe master AxDomain attributes */
 180        reg = dw_pcie_readl_dbi(pci, PCIE_ARUSER_REG);
 181        reg &= ~(AX_USER_DOMAIN_MASK << AX_USER_DOMAIN_SHIFT);
 182        reg |= DOMAIN_OUTER_SHAREABLE << AX_USER_DOMAIN_SHIFT;
 183        dw_pcie_writel_dbi(pci, PCIE_ARUSER_REG, reg);
 184
 185        reg = dw_pcie_readl_dbi(pci, PCIE_AWUSER_REG);
 186        reg &= ~(AX_USER_DOMAIN_MASK << AX_USER_DOMAIN_SHIFT);
 187        reg |= DOMAIN_OUTER_SHAREABLE << AX_USER_DOMAIN_SHIFT;
 188        dw_pcie_writel_dbi(pci, PCIE_AWUSER_REG, reg);
 189
 190        /* Enable INT A-D interrupts */
 191        reg = dw_pcie_readl_dbi(pci, PCIE_GLOBAL_INT_MASK1_REG);
 192        reg |= PCIE_INT_A_ASSERT_MASK | PCIE_INT_B_ASSERT_MASK |
 193               PCIE_INT_C_ASSERT_MASK | PCIE_INT_D_ASSERT_MASK;
 194        dw_pcie_writel_dbi(pci, PCIE_GLOBAL_INT_MASK1_REG, reg);
 195
 196        if (!dw_pcie_link_up(pci)) {
 197                /* Configuration done. Start LTSSM */
 198                reg = dw_pcie_readl_dbi(pci, PCIE_GLOBAL_CONTROL_REG);
 199                reg |= PCIE_APP_LTSSM_EN;
 200                dw_pcie_writel_dbi(pci, PCIE_GLOBAL_CONTROL_REG, reg);
 201        }
 202
 203        /* Wait until the link becomes active again */
 204        if (dw_pcie_wait_for_link(pci))
 205                dev_err(pci->dev, "Link not up after reconfiguration\n");
 206}
 207
 208static int armada8k_pcie_host_init(struct pcie_port *pp)
 209{
 210        struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
 211        struct armada8k_pcie *pcie = to_armada8k_pcie(pci);
 212
 213        dw_pcie_setup_rc(pp);
 214        armada8k_pcie_establish_link(pcie);
 215
 216        return 0;
 217}
 218
 219static irqreturn_t armada8k_pcie_irq_handler(int irq, void *arg)
 220{
 221        struct armada8k_pcie *pcie = arg;
 222        struct dw_pcie *pci = pcie->pci;
 223        u32 val;
 224
 225        /*
 226         * Interrupts are directly handled by the device driver of the
 227         * PCI device. However, they are also latched into the PCIe
 228         * controller, so we simply discard them.
 229         */
 230        val = dw_pcie_readl_dbi(pci, PCIE_GLOBAL_INT_CAUSE1_REG);
 231        dw_pcie_writel_dbi(pci, PCIE_GLOBAL_INT_CAUSE1_REG, val);
 232
 233        return IRQ_HANDLED;
 234}
 235
 236static const struct dw_pcie_host_ops armada8k_pcie_host_ops = {
 237        .host_init = armada8k_pcie_host_init,
 238};
 239
 240static int armada8k_add_pcie_port(struct armada8k_pcie *pcie,
 241                                  struct platform_device *pdev)
 242{
 243        struct dw_pcie *pci = pcie->pci;
 244        struct pcie_port *pp = &pci->pp;
 245        struct device *dev = &pdev->dev;
 246        int ret;
 247
 248        pp->ops = &armada8k_pcie_host_ops;
 249
 250        pp->irq = platform_get_irq(pdev, 0);
 251        if (pp->irq < 0) {
 252                dev_err(dev, "failed to get irq for port\n");
 253                return pp->irq;
 254        }
 255
 256        ret = devm_request_irq(dev, pp->irq, armada8k_pcie_irq_handler,
 257                               IRQF_SHARED, "armada8k-pcie", pcie);
 258        if (ret) {
 259                dev_err(dev, "failed to request irq %d\n", pp->irq);
 260                return ret;
 261        }
 262
 263        ret = dw_pcie_host_init(pp);
 264        if (ret) {
 265                dev_err(dev, "failed to initialize host: %d\n", ret);
 266                return ret;
 267        }
 268
 269        return 0;
 270}
 271
 272static const struct dw_pcie_ops dw_pcie_ops = {
 273        .link_up = armada8k_pcie_link_up,
 274};
 275
 276static int armada8k_pcie_probe(struct platform_device *pdev)
 277{
 278        struct dw_pcie *pci;
 279        struct armada8k_pcie *pcie;
 280        struct device *dev = &pdev->dev;
 281        struct resource *base;
 282        int ret;
 283
 284        pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL);
 285        if (!pcie)
 286                return -ENOMEM;
 287
 288        pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
 289        if (!pci)
 290                return -ENOMEM;
 291
 292        pci->dev = dev;
 293        pci->ops = &dw_pcie_ops;
 294
 295        pcie->pci = pci;
 296
 297        pcie->clk = devm_clk_get(dev, NULL);
 298        if (IS_ERR(pcie->clk))
 299                return PTR_ERR(pcie->clk);
 300
 301        ret = clk_prepare_enable(pcie->clk);
 302        if (ret)
 303                return ret;
 304
 305        pcie->clk_reg = devm_clk_get(dev, "reg");
 306        if (pcie->clk_reg == ERR_PTR(-EPROBE_DEFER)) {
 307                ret = -EPROBE_DEFER;
 308                goto fail;
 309        }
 310        if (!IS_ERR(pcie->clk_reg)) {
 311                ret = clk_prepare_enable(pcie->clk_reg);
 312                if (ret)
 313                        goto fail_clkreg;
 314        }
 315
 316        /* Get the dw-pcie unit configuration/control registers base. */
 317        base = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ctrl");
 318        pci->dbi_base = devm_pci_remap_cfg_resource(dev, base);
 319        if (IS_ERR(pci->dbi_base)) {
 320                dev_err(dev, "couldn't remap regs base %p\n", base);
 321                ret = PTR_ERR(pci->dbi_base);
 322                goto fail_clkreg;
 323        }
 324
 325        ret = armada8k_pcie_setup_phys(pcie);
 326        if (ret)
 327                goto fail_clkreg;
 328
 329        platform_set_drvdata(pdev, pcie);
 330
 331        ret = armada8k_add_pcie_port(pcie, pdev);
 332        if (ret)
 333                goto disable_phy;
 334
 335        return 0;
 336
 337disable_phy:
 338        armada8k_pcie_disable_phys(pcie);
 339fail_clkreg:
 340        clk_disable_unprepare(pcie->clk_reg);
 341fail:
 342        clk_disable_unprepare(pcie->clk);
 343
 344        return ret;
 345}
 346
 347static const struct of_device_id armada8k_pcie_of_match[] = {
 348        { .compatible = "marvell,armada8k-pcie", },
 349        {},
 350};
 351
 352static struct platform_driver armada8k_pcie_driver = {
 353        .probe          = armada8k_pcie_probe,
 354        .driver = {
 355                .name   = "armada8k-pcie",
 356                .of_match_table = of_match_ptr(armada8k_pcie_of_match),
 357                .suppress_bind_attrs = true,
 358        },
 359};
 360builtin_platform_driver(armada8k_pcie_driver);
 361