drivers/platform/x86/intel_punit_ipc.c

   1 /*
   2  * Driver for the Intel P-Unit Mailbox IPC mechanism
   3  *
   4  * (C) Copyright 2015 Intel Corporation
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  * The heart of the P-Unit is the Foxton microcontroller and its firmware,
  11  * which provide mailbox interface for power management usage.
  12  */
  13
  14 #include <linux/module.h>
  15 #include <linux/acpi.h>
  16 #include <linux/delay.h>
  17 #include <linux/bitops.h>
  18 #include <linux/device.h>
  19 #include <linux/interrupt.h>
  20 #include <linux/io.h>
  21 #include <linux/platform_device.h>
  22 #include <asm/intel_punit_ipc.h>
  23
  24 /* IPC Mailbox registers */
  25 #define OFFSET_DATA_LOW         0x0
  26 #define OFFSET_DATA_HIGH        0x4
  27 /* bit field of interface register */
  28 #define CMD_RUN                 BIT(31)
  29 #define CMD_ERRCODE_MASK        GENMASK(7, 0)
  30 #define CMD_PARA1_SHIFT         8
  31 #define CMD_PARA2_SHIFT         16
  32
  33 #define CMD_TIMEOUT_SECONDS     1
  34
  35 enum {
  36         BASE_DATA = 0,
  37         BASE_IFACE,
  38         BASE_MAX,
  39 };
  40
  41 typedef struct {
  42         struct device *dev;
  43         struct mutex lock;
  44         int irq;
  45         struct completion cmd_complete;
  46         /* base of interface and data registers */
  47         void __iomem *base[RESERVED_IPC][BASE_MAX];
  48         IPC_TYPE type;
  49 } IPC_DEV;
  50
  51 static IPC_DEV *punit_ipcdev;
  52
  53 static inline u32 ipc_read_status(IPC_DEV *ipcdev, IPC_TYPE type)
  54 {
  55         return readl(ipcdev->base[type][BASE_IFACE]);
  56 }
  57
  58 static inline void ipc_write_cmd(IPC_DEV *ipcdev, IPC_TYPE type, u32 cmd)
  59 {
  60         writel(cmd, ipcdev->base[type][BASE_IFACE]);
  61 }
  62
  63 static inline u32 ipc_read_data_low(IPC_DEV *ipcdev, IPC_TYPE type)
  64 {
  65         return readl(ipcdev->base[type][BASE_DATA] + OFFSET_DATA_LOW);
  66 }
  67
  68 static inline u32 ipc_read_data_high(IPC_DEV *ipcdev, IPC_TYPE type)
  69 {
  70         return readl(ipcdev->base[type][BASE_DATA] + OFFSET_DATA_HIGH);
  71 }
  72
  73 static inline void ipc_write_data_low(IPC_DEV *ipcdev, IPC_TYPE type, u32 data)
  74 {
  75         writel(data, ipcdev->base[type][BASE_DATA] + OFFSET_DATA_LOW);
  76 }
  77
  78 static inline void ipc_write_data_high(IPC_DEV *ipcdev, IPC_TYPE type, u32 data)
  79 {
  80         writel(data, ipcdev->base[type][BASE_DATA] + OFFSET_DATA_HIGH);
  81 }
  82
  83 static const char *ipc_err_string(int error)
  84 {
  85         if (error == IPC_PUNIT_ERR_SUCCESS)
  86                 return "no error";
  87         else if (error == IPC_PUNIT_ERR_INVALID_CMD)
  88                 return "invalid command";
  89         else if (error == IPC_PUNIT_ERR_INVALID_PARAMETER)
  90                 return "invalid parameter";
  91         else if (error == IPC_PUNIT_ERR_CMD_TIMEOUT)
  92                 return "command timeout";
  93         else if (error == IPC_PUNIT_ERR_CMD_LOCKED)
  94                 return "command locked";
  95         else if (error == IPC_PUNIT_ERR_INVALID_VR_ID)
  96                 return "invalid vr id";
  97         else if (error == IPC_PUNIT_ERR_VR_ERR)
  98                 return "vr error";
  99         else
 100                 return "unknown error";
 101 }
 102
 103 static int intel_punit_ipc_check_status(IPC_DEV *ipcdev, IPC_TYPE type)
 104 {
 105         int loops = CMD_TIMEOUT_SECONDS * USEC_PER_SEC;
 106         int errcode;
 107         int status;
 108
 109         if (ipcdev->irq) {
 110                 if (!wait_for_completion_timeout(&ipcdev->cmd_complete,
 111                                                  CMD_TIMEOUT_SECONDS * HZ)) {
 112                         dev_err(ipcdev->dev, "IPC timed out\n");
 113                         return -ETIMEDOUT;
 114                 }
 115         } else {
 116                 while ((ipc_read_status(ipcdev, type) & CMD_RUN) && --loops)
 117                         udelay(1);
 118                 if (!loops) {
 119                         dev_err(ipcdev->dev, "IPC timed out\n");
 120                         return -ETIMEDOUT;
 121                 }
 122         }
 123
 124         status = ipc_read_status(ipcdev, type);
 125         errcode = status & CMD_ERRCODE_MASK;
 126         if (errcode) {
 127                 dev_err(ipcdev->dev, "IPC failed: %s, IPC_STS=0x%x\n",
 128                         ipc_err_string(errcode), status);
 129                 return -EIO;
 130         }
 131
 132         return 0;
 133 }
 134
 135 /**
 136  * intel_punit_ipc_simple_command() - Simple IPC command
 137  * @cmd:        IPC command code.
 138  * @para1:      First 8bit parameter, set 0 if not used.
 139  * @para2:      Second 8bit parameter, set 0 if not used.
 140  *
 141  * Send a IPC command to P-Unit when there is no data transaction
 142  *
 143  * Return:      IPC error code or 0 on success.
 144  */
 145 int intel_punit_ipc_simple_command(int cmd, int para1, int para2)
 146 {
 147         IPC_DEV *ipcdev = punit_ipcdev;
 148         IPC_TYPE type;
 149         u32 val;
 150         int ret;
 151
 152         mutex_lock(&ipcdev->lock);
 153
 154         reinit_completion(&ipcdev->cmd_complete);
 155         type = (cmd & IPC_PUNIT_CMD_TYPE_MASK) >> IPC_TYPE_OFFSET;
 156
 157         val = cmd & ~IPC_PUNIT_CMD_TYPE_MASK;
 158         val |= CMD_RUN | para2 << CMD_PARA2_SHIFT | para1 << CMD_PARA1_SHIFT;
 159         ipc_write_cmd(ipcdev, type, val);
 160         ret = intel_punit_ipc_check_status(ipcdev, type);
 161
 162         mutex_unlock(&ipcdev->lock);
 163
 164         return ret;
 165 }
 166 EXPORT_SYMBOL(intel_punit_ipc_simple_command);
 167
 168 /**
 169  * intel_punit_ipc_command() - IPC command with data and pointers
 170  * @cmd:        IPC command code.
 171  * @para1:      First 8bit parameter, set 0 if not used.
 172  * @para2:      Second 8bit parameter, set 0 if not used.
 173  * @in:         Input data, 32bit for BIOS cmd, two 32bit for GTD and ISPD.
 174  * @out:        Output data.
 175  *
 176  * Send a IPC command to P-Unit with data transaction
 177  *
 178  * Return:      IPC error code or 0 on success.
 179  */
 180 int intel_punit_ipc_command(u32 cmd, u32 para1, u32 para2, u32 *in, u32 *out)
 181 {
 182         IPC_DEV *ipcdev = punit_ipcdev;
 183         IPC_TYPE type;
 184         u32 val;
 185         int ret;
 186
 187         mutex_lock(&ipcdev->lock);
 188
 189         reinit_completion(&ipcdev->cmd_complete);
 190         type = (cmd & IPC_PUNIT_CMD_TYPE_MASK) >> IPC_TYPE_OFFSET;
 191
 192         if (in) {
 193                 ipc_write_data_low(ipcdev, type, *in);
 194                 if (type == GTDRIVER_IPC || type == ISPDRIVER_IPC)
 195                         ipc_write_data_high(ipcdev, type, *++in);
 196         }
 197
 198         val = cmd & ~IPC_PUNIT_CMD_TYPE_MASK;
 199         val |= CMD_RUN | para2 << CMD_PARA2_SHIFT | para1 << CMD_PARA1_SHIFT;
 200         ipc_write_cmd(ipcdev, type, val);
 201
 202         ret = intel_punit_ipc_check_status(ipcdev, type);
 203         if (ret)
 204                 goto out;
 205
 206         if (out) {
 207                 *out = ipc_read_data_low(ipcdev, type);
 208                 if (type == GTDRIVER_IPC || type == ISPDRIVER_IPC)
 209                         *++out = ipc_read_data_high(ipcdev, type);
 210         }
 211
 212 out:
 213         mutex_unlock(&ipcdev->lock);
 214         return ret;
 215 }
 216 EXPORT_SYMBOL_GPL(intel_punit_ipc_command);
 217
 218 static irqreturn_t intel_punit_ioc(int irq, void *dev_id)
 219 {
 220         IPC_DEV *ipcdev = dev_id;
 221
 222         complete(&ipcdev->cmd_complete);
 223         return IRQ_HANDLED;
 224 }
 225
 226 static int intel_punit_get_bars(struct platform_device *pdev)
 227 {
 228         struct resource *res;
 229         void __iomem *addr;
 230
 231         /*
 232          * The following resources are required
 233          * - BIOS_IPC BASE_DATA
 234          * - BIOS_IPC BASE_IFACE
 235          */
 236         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 237         addr = devm_ioremap_resource(&pdev->dev, res);
 238         if (IS_ERR(addr))
 239                 return PTR_ERR(addr);
 240         punit_ipcdev->base[BIOS_IPC][BASE_DATA] = addr;
 241
 242         res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 243         addr = devm_ioremap_resource(&pdev->dev, res);
 244         if (IS_ERR(addr))
 245                 return PTR_ERR(addr);
 246         punit_ipcdev->base[BIOS_IPC][BASE_IFACE] = addr;
 247
 248         /*
 249          * The following resources are optional
 250          * - ISPDRIVER_IPC BASE_DATA
 251          * - ISPDRIVER_IPC BASE_IFACE
 252          * - GTDRIVER_IPC BASE_DATA
 253          * - GTDRIVER_IPC BASE_IFACE
 254          */
 255         res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
 256         if (res && resource_size(res) > 1) {
 257                 addr = devm_ioremap_resource(&pdev->dev, res);
 258                 if (!IS_ERR(addr))
 259                         punit_ipcdev->base[ISPDRIVER_IPC][BASE_DATA] = addr;
 260         }
 261
 262         res = platform_get_resource(pdev, IORESOURCE_MEM, 3);
 263         if (res && resource_size(res) > 1) {
 264                 addr = devm_ioremap_resource(&pdev->dev, res);
 265                 if (!IS_ERR(addr))
 266                         punit_ipcdev->base[ISPDRIVER_IPC][BASE_IFACE] = addr;
 267         }
 268
 269         res = platform_get_resource(pdev, IORESOURCE_MEM, 4);
 270         if (res && resource_size(res) > 1) {
 271                 addr = devm_ioremap_resource(&pdev->dev, res);
 272                 if (!IS_ERR(addr))
 273                         punit_ipcdev->base[GTDRIVER_IPC][BASE_DATA] = addr;
 274         }
 275
 276         res = platform_get_resource(pdev, IORESOURCE_MEM, 5);
 277         if (res && resource_size(res) > 1) {
 278                 addr = devm_ioremap_resource(&pdev->dev, res);
 279                 if (!IS_ERR(addr))
 280                         punit_ipcdev->base[GTDRIVER_IPC][BASE_IFACE] = addr;
 281         }
 282
 283         return 0;
 284 }
 285
 286 static int intel_punit_ipc_probe(struct platform_device *pdev)
 287 {
 288         int irq, ret;
 289
 290         punit_ipcdev = devm_kzalloc(&pdev->dev,
 291                                     sizeof(*punit_ipcdev), GFP_KERNEL);
 292         if (!punit_ipcdev)
 293                 return -ENOMEM;
 294
 295         platform_set_drvdata(pdev, punit_ipcdev);
 296
 297         irq = platform_get_irq(pdev, 0);
 298         if (irq < 0) {
 299                 punit_ipcdev->irq = 0;
 300                 dev_warn(&pdev->dev, "Invalid IRQ, using polling mode\n");
 301         } else {
 302                 ret = devm_request_irq(&pdev->dev, irq, intel_punit_ioc,
 303                                        IRQF_NO_SUSPEND, "intel_punit_ipc",
 304                                        &punit_ipcdev);
 305                 if (ret) {
 306                         dev_err(&pdev->dev, "Failed to request irq: %d\n", irq);
 307                         return ret;
 308                 }
 309                 punit_ipcdev->irq = irq;
 310         }
 311
 312         ret = intel_punit_get_bars(pdev);
 313         if (ret)
 314                 goto out;
 315
 316         punit_ipcdev->dev = &pdev->dev;
 317         mutex_init(&punit_ipcdev->lock);
 318         init_completion(&punit_ipcdev->cmd_complete);
 319
 320 out:
 321         return ret;
 322 }
 323
 324 static int intel_punit_ipc_remove(struct platform_device *pdev)
 325 {
 326         return 0;
 327 }
 328
 329 static const struct acpi_device_id punit_ipc_acpi_ids[] = {
 330         { "INT34D4", 0 },
 331         { }
 332 };
 333
 334 static struct platform_driver intel_punit_ipc_driver = {
 335         .probe = intel_punit_ipc_probe,
 336         .remove = intel_punit_ipc_remove,
 337         .driver = {
 338                 .name = "intel_punit_ipc",
 339                 .acpi_match_table = ACPI_PTR(punit_ipc_acpi_ids),
 340         },
 341 };
 342
 343 static int __init intel_punit_ipc_init(void)
 344 {
 345         return platform_driver_register(&intel_punit_ipc_driver);
 346 }
 347
 348 static void __exit intel_punit_ipc_exit(void)
 349 {
 350         platform_driver_unregister(&intel_punit_ipc_driver);
 351 }
 352
 353 MODULE_AUTHOR("Zha Qipeng <qipeng.zha@intel.com>");
 354 MODULE_DESCRIPTION("Intel P-Unit IPC driver");
 355 MODULE_LICENSE("GPL v2");
 356
 357 /* Some modules are dependent on this, so init earlier */
 358 fs_initcall(intel_punit_ipc_init);
 359 module_exit(intel_punit_ipc_exit);