drivers/pci/controller/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 };
  30
  31 struct pcie_app_reg {
  32         u32     app_ctrl_0;             /* cr0 */
  33         u32     app_ctrl_1;             /* cr1 */
  34         u32     app_status_0;           /* cr2 */
  35         u32     app_status_1;           /* cr3 */
  36         u32     msg_status;             /* cr4 */
  37         u32     msg_payload;            /* cr5 */
  38         u32     int_sts;                /* cr6 */
  39         u32     int_clr;                /* cr7 */
  40         u32     int_mask;               /* cr8 */
  41         u32     mst_bmisc;              /* cr9 */
  42         u32     phy_ctrl;               /* cr10 */
  43         u32     phy_status;             /* cr11 */
  44         u32     cxpl_debug_info_0;      /* cr12 */
  45         u32     cxpl_debug_info_1;      /* cr13 */
  46         u32     ven_msg_ctrl_0;         /* cr14 */
  47         u32     ven_msg_ctrl_1;         /* cr15 */
  48         u32     ven_msg_data_0;         /* cr16 */
  49         u32     ven_msg_data_1;         /* cr17 */
  50         u32     ven_msi_0;              /* cr18 */
  51         u32     ven_msi_1;              /* cr19 */
  52         u32     mst_rmisc;              /* cr20 */
  53 };
  54
  55 /* CR0 ID */
  56 #define APP_LTSSM_ENABLE_ID                     3
  57 #define DEVICE_TYPE_RC                          (4 << 25)
  58 #define MISCTRL_EN_ID                           30
  59 #define REG_TRANSLATION_ENABLE                  31
  60
  61 /* CR3 ID */
  62 #define XMLH_LINK_UP                            (1 << 6)
  63
  64 /* CR6 */
  65 #define MSI_CTRL_INT                            (1 << 26)
  66
  67 #define to_spear13xx_pcie(x)    dev_get_drvdata((x)->dev)
  68
  69 static int spear13xx_pcie_start_link(struct dw_pcie *pci)
  70 {
  71         struct spear13xx_pcie *spear13xx_pcie = to_spear13xx_pcie(pci);
  72         struct pcie_app_reg *app_reg = spear13xx_pcie->app_base;
  73
  74         /* enable ltssm */
  75         writel(DEVICE_TYPE_RC | (1 << MISCTRL_EN_ID)
  76                         | (1 << APP_LTSSM_ENABLE_ID)
  77                         | ((u32)1 << REG_TRANSLATION_ENABLE),
  78                         &app_reg->app_ctrl_0);
  79
  80         return 0;
  81 }
  82
  83 static irqreturn_t spear13xx_pcie_irq_handler(int irq, void *arg)
  84 {
  85         struct spear13xx_pcie *spear13xx_pcie = arg;
  86         struct pcie_app_reg *app_reg = spear13xx_pcie->app_base;
  87         struct dw_pcie *pci = spear13xx_pcie->pci;
  88         struct pcie_port *pp = &pci->pp;
  89         unsigned int status;
  90
  91         status = readl(&app_reg->int_sts);
  92
  93         if (status & MSI_CTRL_INT) {
  94                 BUG_ON(!IS_ENABLED(CONFIG_PCI_MSI));
  95                 dw_handle_msi_irq(pp);
  96         }
  97
  98         writel(status, &app_reg->int_clr);
  99
 100         return IRQ_HANDLED;
 101 }
 102
 103 static void spear13xx_pcie_enable_interrupts(struct spear13xx_pcie *spear13xx_pcie)
 104 {
 105         struct pcie_app_reg *app_reg = spear13xx_pcie->app_base;
 106
 107         /* Enable MSI interrupt */
 108         if (IS_ENABLED(CONFIG_PCI_MSI))
 109                 writel(readl(&app_reg->int_mask) |
 110                                 MSI_CTRL_INT, &app_reg->int_mask);
 111 }
 112
 113 static int spear13xx_pcie_link_up(struct dw_pcie *pci)
 114 {
 115         struct spear13xx_pcie *spear13xx_pcie = to_spear13xx_pcie(pci);
 116         struct pcie_app_reg *app_reg = spear13xx_pcie->app_base;
 117
 118         if (readl(&app_reg->app_status_1) & XMLH_LINK_UP)
 119                 return 1;
 120
 121         return 0;
 122 }
 123
 124 static int spear13xx_pcie_host_init(struct pcie_port *pp)
 125 {
 126         struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
 127         struct spear13xx_pcie *spear13xx_pcie = to_spear13xx_pcie(pci);
 128         u32 exp_cap_off = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
 129         u32 val;
 130
 131         spear13xx_pcie->app_base = pci->dbi_base + 0x2000;
 132
 133         /*
 134          * this controller support only 128 bytes read size, however its
 135          * default value in capability register is 512 bytes. So force
 136          * it to 128 here.
 137          */
 138         val = dw_pcie_readw_dbi(pci, exp_cap_off + PCI_EXP_DEVCTL);
 139         val &= ~PCI_EXP_DEVCTL_READRQ;
 140         dw_pcie_writew_dbi(pci, exp_cap_off + PCI_EXP_DEVCTL, val);
 141
 142         dw_pcie_writew_dbi(pci, PCI_VENDOR_ID, 0x104A);
 143         dw_pcie_writew_dbi(pci, PCI_DEVICE_ID, 0xCD80);
 144
 145         spear13xx_pcie_enable_interrupts(spear13xx_pcie);
 146
 147         return 0;
 148 }
 149
 150 static const struct dw_pcie_host_ops spear13xx_pcie_host_ops = {
 151         .host_init = spear13xx_pcie_host_init,
 152 };
 153
 154 static int spear13xx_add_pcie_port(struct spear13xx_pcie *spear13xx_pcie,
 155                                    struct platform_device *pdev)
 156 {
 157         struct dw_pcie *pci = spear13xx_pcie->pci;
 158         struct pcie_port *pp = &pci->pp;
 159         struct device *dev = &pdev->dev;
 160         int ret;
 161
 162         pp->irq = platform_get_irq(pdev, 0);
 163         if (pp->irq < 0)
 164                 return pp->irq;
 165
 166         ret = devm_request_irq(dev, pp->irq, spear13xx_pcie_irq_handler,
 167                                IRQF_SHARED | IRQF_NO_THREAD,
 168                                "spear1340-pcie", spear13xx_pcie);
 169         if (ret) {
 170                 dev_err(dev, "failed to request irq %d\n", pp->irq);
 171                 return ret;
 172         }
 173
 174         pp->ops = &spear13xx_pcie_host_ops;
 175         pp->msi_irq = -ENODEV;
 176
 177         ret = dw_pcie_host_init(pp);
 178         if (ret) {
 179                 dev_err(dev, "failed to initialize host\n");
 180                 return ret;
 181         }
 182
 183         return 0;
 184 }
 185
 186 static const struct dw_pcie_ops dw_pcie_ops = {
 187         .link_up = spear13xx_pcie_link_up,
 188         .start_link = spear13xx_pcie_start_link,
 189 };
 190
 191 static int spear13xx_pcie_probe(struct platform_device *pdev)
 192 {
 193         struct device *dev = &pdev->dev;
 194         struct dw_pcie *pci;
 195         struct spear13xx_pcie *spear13xx_pcie;
 196         struct device_node *np = dev->of_node;
 197         int ret;
 198
 199         spear13xx_pcie = devm_kzalloc(dev, sizeof(*spear13xx_pcie), GFP_KERNEL);
 200         if (!spear13xx_pcie)
 201                 return -ENOMEM;
 202
 203         pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
 204         if (!pci)
 205                 return -ENOMEM;
 206
 207         pci->dev = dev;
 208         pci->ops = &dw_pcie_ops;
 209
 210         spear13xx_pcie->pci = pci;
 211
 212         spear13xx_pcie->phy = devm_phy_get(dev, "pcie-phy");
 213         if (IS_ERR(spear13xx_pcie->phy)) {
 214                 ret = PTR_ERR(spear13xx_pcie->phy);
 215                 if (ret == -EPROBE_DEFER)
 216                         dev_info(dev, "probe deferred\n");
 217                 else
 218                         dev_err(dev, "couldn't get pcie-phy\n");
 219                 return ret;
 220         }
 221
 222         phy_init(spear13xx_pcie->phy);
 223
 224         spear13xx_pcie->clk = devm_clk_get(dev, NULL);
 225         if (IS_ERR(spear13xx_pcie->clk)) {
 226                 dev_err(dev, "couldn't get clk for pcie\n");
 227                 return PTR_ERR(spear13xx_pcie->clk);
 228         }
 229         ret = clk_prepare_enable(spear13xx_pcie->clk);
 230         if (ret) {
 231                 dev_err(dev, "couldn't enable clk for pcie\n");
 232                 return ret;
 233         }
 234
 235         if (of_property_read_bool(np, "st,pcie-is-gen1"))
 236                 pci->link_gen = 1;
 237
 238         platform_set_drvdata(pdev, spear13xx_pcie);
 239
 240         ret = spear13xx_add_pcie_port(spear13xx_pcie, pdev);
 241         if (ret < 0)
 242                 goto fail_clk;
 243
 244         return 0;
 245
 246 fail_clk:
 247         clk_disable_unprepare(spear13xx_pcie->clk);
 248
 249         return ret;
 250 }
 251
 252 static const struct of_device_id spear13xx_pcie_of_match[] = {
 253         { .compatible = "st,spear1340-pcie", },
 254         {},
 255 };
 256
 257 static struct platform_driver spear13xx_pcie_driver = {
 258         .probe          = spear13xx_pcie_probe,
 259         .driver = {
 260                 .name   = "spear-pcie",
 261                 .of_match_table = of_match_ptr(spear13xx_pcie_of_match),
 262                 .suppress_bind_attrs = true,
 263         },
 264 };
 265
 266 builtin_platform_driver(spear13xx_pcie_driver);