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