drivers/pci/dwc/pcie-spear13xx.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * PCIe host controller driver for ST Microelectronics SPEAr13xx SoCs
   4  *
   5  * SPEAr13xx PCIe Glue Layer Source Code
   6  *
   7  * Copyright (C) 2010-2014 ST Microelectronics
   8  * Pratyush Anand <pratyush.anand@gmail.com>
   9  * Mohit Kumar <mohit.kumar.dhaka@gmail.com>
  10  */
  11
  12 #include <linux/clk.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/kernel.h>
  15 #include <linux/init.h>
  16 #include <linux/of.h>
  17 #include <linux/pci.h>
  18 #include <linux/phy/phy.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/resource.h>
  21
  22 #include "pcie-designware.h"
  23
  24 struct spear13xx_pcie {
  25         struct dw_pcie          *pci;
  26         void __iomem            *app_base;
  27         struct phy              *phy;
  28         struct clk              *clk;
  29         bool                    is_gen1;
  30 };
  31
  32 struct pcie_app_reg {
  33         u32     app_ctrl_0;             /* cr0 */
  34         u32     app_ctrl_1;             /* cr1 */
  35         u32     app_status_0;           /* cr2 */
  36         u32     app_status_1;           /* cr3 */
  37         u32     msg_status;             /* cr4 */
  38         u32     msg_payload;            /* cr5 */
  39         u32     int_sts;                /* cr6 */
  40         u32     int_clr;                /* cr7 */
  41         u32     int_mask;               /* cr8 */
  42         u32     mst_bmisc;              /* cr9 */
  43         u32     phy_ctrl;               /* cr10 */
  44         u32     phy_status;             /* cr11 */
  45         u32     cxpl_debug_info_0;      /* cr12 */
  46         u32     cxpl_debug_info_1;      /* cr13 */
  47         u32     ven_msg_ctrl_0;         /* cr14 */
  48         u32     ven_msg_ctrl_1;         /* cr15 */
  49         u32     ven_msg_data_0;         /* cr16 */
  50         u32     ven_msg_data_1;         /* cr17 */
  51         u32     ven_msi_0;              /* cr18 */
  52         u32     ven_msi_1;              /* cr19 */
  53         u32     mst_rmisc;              /* cr20 */
  54 };
  55
  56 /* CR0 ID */
  57 #define APP_LTSSM_ENABLE_ID                     3
  58 #define DEVICE_TYPE_RC                          (4 << 25)
  59 #define MISCTRL_EN_ID                           30
  60 #define REG_TRANSLATION_ENABLE                  31
  61
  62 /* CR3 ID */
  63 #define XMLH_LINK_UP                            (1 << 6)
  64
  65 /* CR6 */
  66 #define MSI_CTRL_INT                            (1 << 26)
  67
  68 #define EXP_CAP_ID_OFFSET                       0x70
  69
  70 #define to_spear13xx_pcie(x)    dev_get_drvdata((x)->dev)
  71
  72 static int spear13xx_pcie_establish_link(struct spear13xx_pcie *spear13xx_pcie)
  73 {
  74         struct dw_pcie *pci = spear13xx_pcie->pci;
  75         struct pcie_port *pp = &pci->pp;
  76         struct pcie_app_reg *app_reg = spear13xx_pcie->app_base;
  77         u32 val;
  78         u32 exp_cap_off = EXP_CAP_ID_OFFSET;
  79
  80         if (dw_pcie_link_up(pci)) {
  81                 dev_err(pci->dev, "link already up\n");
  82                 return 0;
  83         }
  84
  85         dw_pcie_setup_rc(pp);
  86
  87         /*
  88          * this controller support only 128 bytes read size, however its
  89          * default value in capability register is 512 bytes. So force
  90          * it to 128 here.
  91          */
  92         dw_pcie_read(pci->dbi_base + exp_cap_off + PCI_EXP_DEVCTL, 2, &val);
  93         val &= ~PCI_EXP_DEVCTL_READRQ;
  94         dw_pcie_write(pci->dbi_base + exp_cap_off + PCI_EXP_DEVCTL, 2, val);
  95
  96         dw_pcie_write(pci->dbi_base + PCI_VENDOR_ID, 2, 0x104A);
  97         dw_pcie_write(pci->dbi_base + PCI_DEVICE_ID, 2, 0xCD80);
  98
  99         /*
 100          * if is_gen1 is set then handle it, so that some buggy card
 101          * also works
 102          */
 103         if (spear13xx_pcie->is_gen1) {
 104                 dw_pcie_read(pci->dbi_base + exp_cap_off + PCI_EXP_LNKCAP,
 105                              4, &val);
 106                 if ((val & PCI_EXP_LNKCAP_SLS) != PCI_EXP_LNKCAP_SLS_2_5GB) {
 107                         val &= ~((u32)PCI_EXP_LNKCAP_SLS);
 108                         val |= PCI_EXP_LNKCAP_SLS_2_5GB;
 109                         dw_pcie_write(pci->dbi_base + exp_cap_off +
 110                                       PCI_EXP_LNKCAP, 4, val);
 111                 }
 112
 113                 dw_pcie_read(pci->dbi_base + exp_cap_off + PCI_EXP_LNKCTL2,
 114                              2, &val);
 115                 if ((val & PCI_EXP_LNKCAP_SLS) != PCI_EXP_LNKCAP_SLS_2_5GB) {
 116                         val &= ~((u32)PCI_EXP_LNKCAP_SLS);
 117                         val |= PCI_EXP_LNKCAP_SLS_2_5GB;
 118                         dw_pcie_write(pci->dbi_base + exp_cap_off +
 119                                       PCI_EXP_LNKCTL2, 2, val);
 120                 }
 121         }
 122
 123         /* enable ltssm */
 124         writel(DEVICE_TYPE_RC | (1 << MISCTRL_EN_ID)
 125                         | (1 << APP_LTSSM_ENABLE_ID)
 126                         | ((u32)1 << REG_TRANSLATION_ENABLE),
 127                         &app_reg->app_ctrl_0);
 128
 129         return dw_pcie_wait_for_link(pci);
 130 }
 131
 132 static irqreturn_t spear13xx_pcie_irq_handler(int irq, void *arg)
 133 {
 134         struct spear13xx_pcie *spear13xx_pcie = arg;
 135         struct pcie_app_reg *app_reg = spear13xx_pcie->app_base;
 136         struct dw_pcie *pci = spear13xx_pcie->pci;
 137         struct pcie_port *pp = &pci->pp;
 138         unsigned int status;
 139
 140         status = readl(&app_reg->int_sts);
 141
 142         if (status & MSI_CTRL_INT) {
 143                 BUG_ON(!IS_ENABLED(CONFIG_PCI_MSI));
 144                 dw_handle_msi_irq(pp);
 145         }
 146
 147         writel(status, &app_reg->int_clr);
 148
 149         return IRQ_HANDLED;
 150 }
 151
 152 static void spear13xx_pcie_enable_interrupts(struct spear13xx_pcie *spear13xx_pcie)
 153 {
 154         struct dw_pcie *pci = spear13xx_pcie->pci;
 155         struct pcie_port *pp = &pci->pp;
 156         struct pcie_app_reg *app_reg = spear13xx_pcie->app_base;
 157
 158         /* Enable MSI interrupt */
 159         if (IS_ENABLED(CONFIG_PCI_MSI)) {
 160                 dw_pcie_msi_init(pp);
 161                 writel(readl(&app_reg->int_mask) |
 162                                 MSI_CTRL_INT, &app_reg->int_mask);
 163         }
 164 }
 165
 166 static int spear13xx_pcie_link_up(struct dw_pcie *pci)
 167 {
 168         struct spear13xx_pcie *spear13xx_pcie = to_spear13xx_pcie(pci);
 169         struct pcie_app_reg *app_reg = spear13xx_pcie->app_base;
 170
 171         if (readl(&app_reg->app_status_1) & XMLH_LINK_UP)
 172                 return 1;
 173
 174         return 0;
 175 }
 176
 177 static int spear13xx_pcie_host_init(struct pcie_port *pp)
 178 {
 179         struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
 180         struct spear13xx_pcie *spear13xx_pcie = to_spear13xx_pcie(pci);
 181
 182         spear13xx_pcie_establish_link(spear13xx_pcie);
 183         spear13xx_pcie_enable_interrupts(spear13xx_pcie);
 184
 185         return 0;
 186 }
 187
 188 static const struct dw_pcie_host_ops spear13xx_pcie_host_ops = {
 189         .host_init = spear13xx_pcie_host_init,
 190 };
 191
 192 static int spear13xx_add_pcie_port(struct spear13xx_pcie *spear13xx_pcie,
 193                                    struct platform_device *pdev)
 194 {
 195         struct dw_pcie *pci = spear13xx_pcie->pci;
 196         struct pcie_port *pp = &pci->pp;
 197         struct device *dev = &pdev->dev;
 198         int ret;
 199
 200         pp->irq = platform_get_irq(pdev, 0);
 201         if (pp->irq < 0) {
 202                 dev_err(dev, "failed to get irq\n");
 203                 return pp->irq;
 204         }
 205         ret = devm_request_irq(dev, pp->irq, spear13xx_pcie_irq_handler,
 206                                IRQF_SHARED | IRQF_NO_THREAD,
 207                                "spear1340-pcie", spear13xx_pcie);
 208         if (ret) {
 209                 dev_err(dev, "failed to request irq %d\n", pp->irq);
 210                 return ret;
 211         }
 212
 213         pp->root_bus_nr = -1;
 214         pp->ops = &spear13xx_pcie_host_ops;
 215
 216         ret = dw_pcie_host_init(pp);
 217         if (ret) {
 218                 dev_err(dev, "failed to initialize host\n");
 219                 return ret;
 220         }
 221
 222         return 0;
 223 }
 224
 225 static const struct dw_pcie_ops dw_pcie_ops = {
 226         .link_up = spear13xx_pcie_link_up,
 227 };
 228
 229 static int spear13xx_pcie_probe(struct platform_device *pdev)
 230 {
 231         struct device *dev = &pdev->dev;
 232         struct dw_pcie *pci;
 233         struct spear13xx_pcie *spear13xx_pcie;
 234         struct device_node *np = dev->of_node;
 235         struct resource *dbi_base;
 236         int ret;
 237
 238         spear13xx_pcie = devm_kzalloc(dev, sizeof(*spear13xx_pcie), GFP_KERNEL);
 239         if (!spear13xx_pcie)
 240                 return -ENOMEM;
 241
 242         pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
 243         if (!pci)
 244                 return -ENOMEM;
 245
 246         pci->dev = dev;
 247         pci->ops = &dw_pcie_ops;
 248
 249         spear13xx_pcie->pci = pci;
 250
 251         spear13xx_pcie->phy = devm_phy_get(dev, "pcie-phy");
 252         if (IS_ERR(spear13xx_pcie->phy)) {
 253                 ret = PTR_ERR(spear13xx_pcie->phy);
 254                 if (ret == -EPROBE_DEFER)
 255                         dev_info(dev, "probe deferred\n");
 256                 else
 257                         dev_err(dev, "couldn't get pcie-phy\n");
 258                 return ret;
 259         }
 260
 261         phy_init(spear13xx_pcie->phy);
 262
 263         spear13xx_pcie->clk = devm_clk_get(dev, NULL);
 264         if (IS_ERR(spear13xx_pcie->clk)) {
 265                 dev_err(dev, "couldn't get clk for pcie\n");
 266                 return PTR_ERR(spear13xx_pcie->clk);
 267         }
 268         ret = clk_prepare_enable(spear13xx_pcie->clk);
 269         if (ret) {
 270                 dev_err(dev, "couldn't enable clk for pcie\n");
 271                 return ret;
 272         }
 273
 274         dbi_base = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dbi");
 275         pci->dbi_base = devm_pci_remap_cfg_resource(dev, dbi_base);
 276         if (IS_ERR(pci->dbi_base)) {
 277                 dev_err(dev, "couldn't remap dbi base %p\n", dbi_base);
 278                 ret = PTR_ERR(pci->dbi_base);
 279                 goto fail_clk;
 280         }
 281         spear13xx_pcie->app_base = pci->dbi_base + 0x2000;
 282
 283         if (of_property_read_bool(np, "st,pcie-is-gen1"))
 284                 spear13xx_pcie->is_gen1 = true;
 285
 286         platform_set_drvdata(pdev, spear13xx_pcie);
 287
 288         ret = spear13xx_add_pcie_port(spear13xx_pcie, pdev);
 289         if (ret < 0)
 290                 goto fail_clk;
 291
 292         return 0;
 293
 294 fail_clk:
 295         clk_disable_unprepare(spear13xx_pcie->clk);
 296
 297         return ret;
 298 }
 299
 300 static const struct of_device_id spear13xx_pcie_of_match[] = {
 301         { .compatible = "st,spear1340-pcie", },
 302         {},
 303 };
 304
 305 static struct platform_driver spear13xx_pcie_driver = {
 306         .probe          = spear13xx_pcie_probe,
 307         .driver = {
 308                 .name   = "spear-pcie",
 309                 .of_match_table = of_match_ptr(spear13xx_pcie_of_match),
 310                 .suppress_bind_attrs = true,
 311         },
 312 };
 313
 314 builtin_platform_driver(spear13xx_pcie_driver);