drivers/platform/x86/intel/punit_ipc.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Driver for the Intel P-Unit Mailbox IPC mechanism
   4  *
   5  * (C) Copyright 2015 Intel Corporation
   6  *
   7  * The heart of the P-Unit is the Foxton microcontroller and its firmware,
   8  * which provide mailbox interface for power management usage.
   9  */
  10
  11 #include <linux/bitops.h>
  12 #include <linux/delay.h>
  13 #include <linux/device.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/io.h>
  16 #include <linux/mod_devicetable.h>
  17 #include <linux/module.h>
  18 #include <linux/platform_device.h>
  19
  20 #include <asm/intel_punit_ipc.h>
  21
  22 /* IPC Mailbox registers */
  23 #define OFFSET_DATA_LOW         0x0
  24 #define OFFSET_DATA_HIGH        0x4
  25 /* bit field of interface register */
  26 #define CMD_RUN                 BIT(31)
  27 #define CMD_ERRCODE_MASK        GENMASK(7, 0)
  28 #define CMD_PARA1_SHIFT         8
  29 #define CMD_PARA2_SHIFT         16
  30
  31 #define CMD_TIMEOUT_SECONDS     1
  32
  33 enum {
  34         BASE_DATA = 0,
  35         BASE_IFACE,
  36         BASE_MAX,
  37 };
  38
  39 typedef struct {
  40         struct device *dev;
  41         struct mutex lock;
  42         int irq;
  43         struct completion cmd_complete;
  44         /* base of interface and data registers */
  45         void __iomem *base[RESERVED_IPC][BASE_MAX];
  46         IPC_TYPE type;
  47 } IPC_DEV;
  48
  49 static IPC_DEV *punit_ipcdev;
  50
  51 static inline u32 ipc_read_status(IPC_DEV *ipcdev, IPC_TYPE type)
  52 {
  53         return readl(ipcdev->base[type][BASE_IFACE]);
  54 }
  55
  56 static inline void ipc_write_cmd(IPC_DEV *ipcdev, IPC_TYPE type, u32 cmd)
  57 {
  58         writel(cmd, ipcdev->base[type][BASE_IFACE]);
  59 }
  60
  61 static inline u32 ipc_read_data_low(IPC_DEV *ipcdev, IPC_TYPE type)
  62 {
  63         return readl(ipcdev->base[type][BASE_DATA] + OFFSET_DATA_LOW);
  64 }
  65
  66 static inline u32 ipc_read_data_high(IPC_DEV *ipcdev, IPC_TYPE type)
  67 {
  68         return readl(ipcdev->base[type][BASE_DATA] + OFFSET_DATA_HIGH);
  69 }
  70
  71 static inline void ipc_write_data_low(IPC_DEV *ipcdev, IPC_TYPE type, u32 data)
  72 {
  73         writel(data, ipcdev->base[type][BASE_DATA] + OFFSET_DATA_LOW);
  74 }
  75
  76 static inline void ipc_write_data_high(IPC_DEV *ipcdev, IPC_TYPE type, u32 data)
  77 {
  78         writel(data, ipcdev->base[type][BASE_DATA] + OFFSET_DATA_HIGH);
  79 }
  80
  81 static const char *ipc_err_string(int error)
  82 {
  83         if (error == IPC_PUNIT_ERR_SUCCESS)
  84                 return "no error";
  85         else if (error == IPC_PUNIT_ERR_INVALID_CMD)
  86                 return "invalid command";
  87         else if (error == IPC_PUNIT_ERR_INVALID_PARAMETER)
  88                 return "invalid parameter";
  89         else if (error == IPC_PUNIT_ERR_CMD_TIMEOUT)
  90                 return "command timeout";
  91         else if (error == IPC_PUNIT_ERR_CMD_LOCKED)
  92                 return "command locked";
  93         else if (error == IPC_PUNIT_ERR_INVALID_VR_ID)
  94                 return "invalid vr id";
  95         else if (error == IPC_PUNIT_ERR_VR_ERR)
  96                 return "vr error";
  97         else
  98                 return "unknown error";
  99 }
 100
 101 static int intel_punit_ipc_check_status(IPC_DEV *ipcdev, IPC_TYPE type)
 102 {
 103         int loops = CMD_TIMEOUT_SECONDS * USEC_PER_SEC;
 104         int errcode;
 105         int status;
 106
 107         if (ipcdev->irq) {
 108                 if (!wait_for_completion_timeout(&ipcdev->cmd_complete,
 109                                                  CMD_TIMEOUT_SECONDS * HZ)) {
 110                         dev_err(ipcdev->dev, "IPC timed out\n");
 111                         return -ETIMEDOUT;
 112                 }
 113         } else {
 114                 while ((ipc_read_status(ipcdev, type) & CMD_RUN) && --loops)
 115                         udelay(1);
 116                 if (!loops) {
 117                         dev_err(ipcdev->dev, "IPC timed out\n");
 118                         return -ETIMEDOUT;
 119                 }
 120         }
 121
 122         status = ipc_read_status(ipcdev, type);
 123         errcode = status & CMD_ERRCODE_MASK;
 124         if (errcode) {
 125                 dev_err(ipcdev->dev, "IPC failed: %s, IPC_STS=0x%x\n",
 126                         ipc_err_string(errcode), status);
 127                 return -EIO;
 128         }
 129
 130         return 0;
 131 }
 132
 133 /**
 134  * intel_punit_ipc_simple_command() - Simple IPC command
 135  * @cmd:        IPC command code.
 136  * @para1:      First 8bit parameter, set 0 if not used.
 137  * @para2:      Second 8bit parameter, set 0 if not used.
 138  *
 139  * Send a IPC command to P-Unit when there is no data transaction
 140  *
 141  * Return:      IPC error code or 0 on success.
 142  */
 143 int intel_punit_ipc_simple_command(int cmd, int para1, int para2)
 144 {
 145         IPC_DEV *ipcdev = punit_ipcdev;
 146         IPC_TYPE type;
 147         u32 val;
 148         int ret;
 149
 150         mutex_lock(&ipcdev->lock);
 151
 152         reinit_completion(&ipcdev->cmd_complete);
 153         type = (cmd & IPC_PUNIT_CMD_TYPE_MASK) >> IPC_TYPE_OFFSET;
 154
 155         val = cmd & ~IPC_PUNIT_CMD_TYPE_MASK;
 156         val |= CMD_RUN | para2 << CMD_PARA2_SHIFT | para1 << CMD_PARA1_SHIFT;
 157         ipc_write_cmd(ipcdev, type, val);
 158         ret = intel_punit_ipc_check_status(ipcdev, type);
 159
 160         mutex_unlock(&ipcdev->lock);
 161
 162         return ret;
 163 }
 164 EXPORT_SYMBOL(intel_punit_ipc_simple_command);
 165
 166 /**
 167  * intel_punit_ipc_command() - IPC command with data and pointers
 168  * @cmd:        IPC command code.
 169  * @para1:      First 8bit parameter, set 0 if not used.
 170  * @para2:      Second 8bit parameter, set 0 if not used.
 171  * @in:         Input data, 32bit for BIOS cmd, two 32bit for GTD and ISPD.
 172  * @out:        Output data.
 173  *
 174  * Send a IPC command to P-Unit with data transaction
 175  *
 176  * Return:      IPC error code or 0 on success.
 177  */
 178 int intel_punit_ipc_command(u32 cmd, u32 para1, u32 para2, u32 *in, u32 *out)
 179 {
 180         IPC_DEV *ipcdev = punit_ipcdev;
 181         IPC_TYPE type;
 182         u32 val;
 183         int ret;
 184
 185         mutex_lock(&ipcdev->lock);
 186
 187         reinit_completion(&ipcdev->cmd_complete);
 188         type = (cmd & IPC_PUNIT_CMD_TYPE_MASK) >> IPC_TYPE_OFFSET;
 189
 190         if (in) {
 191                 ipc_write_data_low(ipcdev, type, *in);
 192                 if (type == GTDRIVER_IPC || type == ISPDRIVER_IPC)
 193                         ipc_write_data_high(ipcdev, type, *++in);
 194         }
 195
 196         val = cmd & ~IPC_PUNIT_CMD_TYPE_MASK;
 197         val |= CMD_RUN | para2 << CMD_PARA2_SHIFT | para1 << CMD_PARA1_SHIFT;
 198         ipc_write_cmd(ipcdev, type, val);
 199
 200         ret = intel_punit_ipc_check_status(ipcdev, type);
 201         if (ret)
 202                 goto out;
 203
 204         if (out) {
 205                 *out = ipc_read_data_low(ipcdev, type);
 206                 if (type == GTDRIVER_IPC || type == ISPDRIVER_IPC)
 207                         *++out = ipc_read_data_high(ipcdev, type);
 208         }
 209
 210 out:
 211         mutex_unlock(&ipcdev->lock);
 212         return ret;
 213 }
 214 EXPORT_SYMBOL_GPL(intel_punit_ipc_command);
 215
 216 static irqreturn_t intel_punit_ioc(int irq, void *dev_id)
 217 {
 218         IPC_DEV *ipcdev = dev_id;
 219
 220         complete(&ipcdev->cmd_complete);
 221         return IRQ_HANDLED;
 222 }
 223
 224 static int intel_punit_get_bars(struct platform_device *pdev)
 225 {
 226         void __iomem *addr;
 227
 228         /*
 229          * The following resources are required
 230          * - BIOS_IPC BASE_DATA
 231          * - BIOS_IPC BASE_IFACE
 232          */
 233         addr = devm_platform_ioremap_resource(pdev, 0);
 234         if (IS_ERR(addr))
 235                 return PTR_ERR(addr);
 236         punit_ipcdev->base[BIOS_IPC][BASE_DATA] = addr;
 237
 238         addr = devm_platform_ioremap_resource(pdev, 1);
 239         if (IS_ERR(addr))
 240                 return PTR_ERR(addr);
 241         punit_ipcdev->base[BIOS_IPC][BASE_IFACE] = addr;
 242
 243         /*
 244          * The following resources are optional
 245          * - ISPDRIVER_IPC BASE_DATA
 246          * - ISPDRIVER_IPC BASE_IFACE
 247          * - GTDRIVER_IPC BASE_DATA
 248          * - GTDRIVER_IPC BASE_IFACE
 249          */
 250         addr = devm_platform_ioremap_resource(pdev, 2);
 251         if (!IS_ERR(addr))
 252                 punit_ipcdev->base[ISPDRIVER_IPC][BASE_DATA] = addr;
 253
 254         addr = devm_platform_ioremap_resource(pdev, 3);
 255         if (!IS_ERR(addr))
 256                 punit_ipcdev->base[ISPDRIVER_IPC][BASE_IFACE] = addr;
 257
 258         addr = devm_platform_ioremap_resource(pdev, 4);
 259         if (!IS_ERR(addr))
 260                 punit_ipcdev->base[GTDRIVER_IPC][BASE_DATA] = addr;
 261
 262         addr = devm_platform_ioremap_resource(pdev, 5);
 263         if (!IS_ERR(addr))
 264                 punit_ipcdev->base[GTDRIVER_IPC][BASE_IFACE] = addr;
 265
 266         return 0;
 267 }
 268
 269 static int intel_punit_ipc_probe(struct platform_device *pdev)
 270 {
 271         int irq, ret;
 272
 273         punit_ipcdev = devm_kzalloc(&pdev->dev,
 274                                     sizeof(*punit_ipcdev), GFP_KERNEL);
 275         if (!punit_ipcdev)
 276                 return -ENOMEM;
 277
 278         platform_set_drvdata(pdev, punit_ipcdev);
 279
 280         irq = platform_get_irq_optional(pdev, 0);
 281         if (irq < 0) {
 282                 dev_warn(&pdev->dev, "Invalid IRQ, using polling mode\n");
 283         } else {
 284                 ret = devm_request_irq(&pdev->dev, irq, intel_punit_ioc,
 285                                        IRQF_NO_SUSPEND, "intel_punit_ipc",
 286                                        &punit_ipcdev);
 287                 if (ret) {
 288                         dev_err(&pdev->dev, "Failed to request irq: %d\n", irq);
 289                         return ret;
 290                 }
 291                 punit_ipcdev->irq = irq;
 292         }
 293
 294         ret = intel_punit_get_bars(pdev);
 295         if (ret)
 296                 return ret;
 297
 298         punit_ipcdev->dev = &pdev->dev;
 299         mutex_init(&punit_ipcdev->lock);
 300         init_completion(&punit_ipcdev->cmd_complete);
 301
 302         return 0;
 303 }
 304
 305 static int intel_punit_ipc_remove(struct platform_device *pdev)
 306 {
 307         return 0;
 308 }
 309
 310 static const struct acpi_device_id punit_ipc_acpi_ids[] = {
 311         { "INT34D4", 0 },
 312         { }
 313 };
 314 MODULE_DEVICE_TABLE(acpi, punit_ipc_acpi_ids);
 315
 316 static struct platform_driver intel_punit_ipc_driver = {
 317         .probe = intel_punit_ipc_probe,
 318         .remove = intel_punit_ipc_remove,
 319         .driver = {
 320                 .name = "intel_punit_ipc",
 321                 .acpi_match_table = punit_ipc_acpi_ids,
 322         },
 323 };
 324
 325 static int __init intel_punit_ipc_init(void)
 326 {
 327         return platform_driver_register(&intel_punit_ipc_driver);
 328 }
 329
 330 static void __exit intel_punit_ipc_exit(void)
 331 {
 332         platform_driver_unregister(&intel_punit_ipc_driver);
 333 }
 334
 335 MODULE_AUTHOR("Zha Qipeng <qipeng.zha@intel.com>");
 336 MODULE_DESCRIPTION("Intel P-Unit IPC driver");
 337 MODULE_LICENSE("GPL v2");
 338
 339 /* Some modules are dependent on this, so init earlier */
 340 fs_initcall(intel_punit_ipc_init);
 341 module_exit(intel_punit_ipc_exit);