x86/intel/punit_ipc.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  * Driver for the Intel P-Unit Mailbox IPC mechanism
0004  *
0005  * (C) Copyright 2015 Intel Corporation
0006  *
0007  * The heart of the P-Unit is the Foxton microcontroller and its firmware,
0008  * which provide mailbox interface for power management usage.
0009  */
0010
0011 #include <linux/bitops.h>
0012 #include <linux/delay.h>
0013 #include <linux/device.h>
0014 #include <linux/interrupt.h>
0015 #include <linux/io.h>
0016 #include <linux/mod_devicetable.h>
0017 #include <linux/module.h>
0018 #include <linux/platform_device.h>
0019
0020 #include <asm/intel_punit_ipc.h>
0021
0022 /* IPC Mailbox registers */
0023 #define OFFSET_DATA_LOW     0x0
0024 #define OFFSET_DATA_HIGH    0x4
0025 /* bit field of interface register */
0026 #define CMD_RUN         BIT(31)
0027 #define CMD_ERRCODE_MASK    GENMASK(7, 0)
0028 #define CMD_PARA1_SHIFT     8
0029 #define CMD_PARA2_SHIFT     16
0030
0031 #define CMD_TIMEOUT_SECONDS 1
0032
0033 enum {
0034     BASE_DATA = 0,
0035     BASE_IFACE,
0036     BASE_MAX,
0037 };
0038
0039 typedef struct {
0040     struct device *dev;
0041     struct mutex lock;
0042     int irq;
0043     struct completion cmd_complete;
0044     /* base of interface and data registers */
0045     void __iomem *base[RESERVED_IPC][BASE_MAX];
0046     IPC_TYPE type;
0047 } IPC_DEV;
0048
0049 static IPC_DEV *punit_ipcdev;
0050
0051 static inline u32 ipc_read_status(IPC_DEV *ipcdev, IPC_TYPE type)
0052 {
0053     return readl(ipcdev->base[type][BASE_IFACE]);
0054 }
0055
0056 static inline void ipc_write_cmd(IPC_DEV *ipcdev, IPC_TYPE type, u32 cmd)
0057 {
0058     writel(cmd, ipcdev->base[type][BASE_IFACE]);
0059 }
0060
0061 static inline u32 ipc_read_data_low(IPC_DEV *ipcdev, IPC_TYPE type)
0062 {
0063     return readl(ipcdev->base[type][BASE_DATA] + OFFSET_DATA_LOW);
0064 }
0065
0066 static inline u32 ipc_read_data_high(IPC_DEV *ipcdev, IPC_TYPE type)
0067 {
0068     return readl(ipcdev->base[type][BASE_DATA] + OFFSET_DATA_HIGH);
0069 }
0070
0071 static inline void ipc_write_data_low(IPC_DEV *ipcdev, IPC_TYPE type, u32 data)
0072 {
0073     writel(data, ipcdev->base[type][BASE_DATA] + OFFSET_DATA_LOW);
0074 }
0075
0076 static inline void ipc_write_data_high(IPC_DEV *ipcdev, IPC_TYPE type, u32 data)
0077 {
0078     writel(data, ipcdev->base[type][BASE_DATA] + OFFSET_DATA_HIGH);
0079 }
0080
0081 static const char *ipc_err_string(int error)
0082 {
0083     if (error == IPC_PUNIT_ERR_SUCCESS)
0084         return "no error";
0085     else if (error == IPC_PUNIT_ERR_INVALID_CMD)
0086         return "invalid command";
0087     else if (error == IPC_PUNIT_ERR_INVALID_PARAMETER)
0088         return "invalid parameter";
0089     else if (error == IPC_PUNIT_ERR_CMD_TIMEOUT)
0090         return "command timeout";
0091     else if (error == IPC_PUNIT_ERR_CMD_LOCKED)
0092         return "command locked";
0093     else if (error == IPC_PUNIT_ERR_INVALID_VR_ID)
0094         return "invalid vr id";
0095     else if (error == IPC_PUNIT_ERR_VR_ERR)
0096         return "vr error";
0097     else
0098         return "unknown error";
0099 }
0100
0101 static int intel_punit_ipc_check_status(IPC_DEV *ipcdev, IPC_TYPE type)
0102 {
0103     int loops = CMD_TIMEOUT_SECONDS * USEC_PER_SEC;
0104     int errcode;
0105     int status;
0106
0107     if (ipcdev->irq) {
0108         if (!wait_for_completion_timeout(&ipcdev->cmd_complete,
0109                          CMD_TIMEOUT_SECONDS * HZ)) {
0110             dev_err(ipcdev->dev, "IPC timed out\n");
0111             return -ETIMEDOUT;
0112         }
0113     } else {
0114         while ((ipc_read_status(ipcdev, type) & CMD_RUN) && --loops)
0115             udelay(1);
0116         if (!loops) {
0117             dev_err(ipcdev->dev, "IPC timed out\n");
0118             return -ETIMEDOUT;
0119         }
0120     }
0121
0122     status = ipc_read_status(ipcdev, type);
0123     errcode = status & CMD_ERRCODE_MASK;
0124     if (errcode) {
0125         dev_err(ipcdev->dev, "IPC failed: %s, IPC_STS=0x%x\n",
0126             ipc_err_string(errcode), status);
0127         return -EIO;
0128     }
0129
0130     return 0;
0131 }
0132
0133 /**
0134  * intel_punit_ipc_simple_command() - Simple IPC command
0135  * @cmd:    IPC command code.
0136  * @para1:  First 8bit parameter, set 0 if not used.
0137  * @para2:  Second 8bit parameter, set 0 if not used.
0138  *
0139  * Send a IPC command to P-Unit when there is no data transaction
0140  *
0141  * Return:  IPC error code or 0 on success.
0142  */
0143 int intel_punit_ipc_simple_command(int cmd, int para1, int para2)
0144 {
0145     IPC_DEV *ipcdev = punit_ipcdev;
0146     IPC_TYPE type;
0147     u32 val;
0148     int ret;
0149
0150     mutex_lock(&ipcdev->lock);
0151
0152     reinit_completion(&ipcdev->cmd_complete);
0153     type = (cmd & IPC_PUNIT_CMD_TYPE_MASK) >> IPC_TYPE_OFFSET;
0154
0155     val = cmd & ~IPC_PUNIT_CMD_TYPE_MASK;
0156     val |= CMD_RUN | para2 << CMD_PARA2_SHIFT | para1 << CMD_PARA1_SHIFT;
0157     ipc_write_cmd(ipcdev, type, val);
0158     ret = intel_punit_ipc_check_status(ipcdev, type);
0159
0160     mutex_unlock(&ipcdev->lock);
0161
0162     return ret;
0163 }
0164 EXPORT_SYMBOL(intel_punit_ipc_simple_command);
0165
0166 /**
0167  * intel_punit_ipc_command() - IPC command with data and pointers
0168  * @cmd:    IPC command code.
0169  * @para1:  First 8bit parameter, set 0 if not used.
0170  * @para2:  Second 8bit parameter, set 0 if not used.
0171  * @in:     Input data, 32bit for BIOS cmd, two 32bit for GTD and ISPD.
0172  * @out:    Output data.
0173  *
0174  * Send a IPC command to P-Unit with data transaction
0175  *
0176  * Return:  IPC error code or 0 on success.
0177  */
0178 int intel_punit_ipc_command(u32 cmd, u32 para1, u32 para2, u32 *in, u32 *out)
0179 {
0180     IPC_DEV *ipcdev = punit_ipcdev;
0181     IPC_TYPE type;
0182     u32 val;
0183     int ret;
0184
0185     mutex_lock(&ipcdev->lock);
0186
0187     reinit_completion(&ipcdev->cmd_complete);
0188     type = (cmd & IPC_PUNIT_CMD_TYPE_MASK) >> IPC_TYPE_OFFSET;
0189
0190     if (in) {
0191         ipc_write_data_low(ipcdev, type, *in);
0192         if (type == GTDRIVER_IPC || type == ISPDRIVER_IPC)
0193             ipc_write_data_high(ipcdev, type, *++in);
0194     }
0195
0196     val = cmd & ~IPC_PUNIT_CMD_TYPE_MASK;
0197     val |= CMD_RUN | para2 << CMD_PARA2_SHIFT | para1 << CMD_PARA1_SHIFT;
0198     ipc_write_cmd(ipcdev, type, val);
0199
0200     ret = intel_punit_ipc_check_status(ipcdev, type);
0201     if (ret)
0202         goto out;
0203
0204     if (out) {
0205         *out = ipc_read_data_low(ipcdev, type);
0206         if (type == GTDRIVER_IPC || type == ISPDRIVER_IPC)
0207             *++out = ipc_read_data_high(ipcdev, type);
0208     }
0209
0210 out:
0211     mutex_unlock(&ipcdev->lock);
0212     return ret;
0213 }
0214 EXPORT_SYMBOL_GPL(intel_punit_ipc_command);
0215
0216 static irqreturn_t intel_punit_ioc(int irq, void *dev_id)
0217 {
0218     IPC_DEV *ipcdev = dev_id;
0219
0220     complete(&ipcdev->cmd_complete);
0221     return IRQ_HANDLED;
0222 }
0223
0224 static int intel_punit_get_bars(struct platform_device *pdev)
0225 {
0226     void __iomem *addr;
0227
0228     /*
0229      * The following resources are required
0230      * - BIOS_IPC BASE_DATA
0231      * - BIOS_IPC BASE_IFACE
0232      */
0233     addr = devm_platform_ioremap_resource(pdev, 0);
0234     if (IS_ERR(addr))
0235         return PTR_ERR(addr);
0236     punit_ipcdev->base[BIOS_IPC][BASE_DATA] = addr;
0237
0238     addr = devm_platform_ioremap_resource(pdev, 1);
0239     if (IS_ERR(addr))
0240         return PTR_ERR(addr);
0241     punit_ipcdev->base[BIOS_IPC][BASE_IFACE] = addr;
0242
0243     /*
0244      * The following resources are optional
0245      * - ISPDRIVER_IPC BASE_DATA
0246      * - ISPDRIVER_IPC BASE_IFACE
0247      * - GTDRIVER_IPC BASE_DATA
0248      * - GTDRIVER_IPC BASE_IFACE
0249      */
0250     addr = devm_platform_ioremap_resource(pdev, 2);
0251     if (!IS_ERR(addr))
0252         punit_ipcdev->base[ISPDRIVER_IPC][BASE_DATA] = addr;
0253
0254     addr = devm_platform_ioremap_resource(pdev, 3);
0255     if (!IS_ERR(addr))
0256         punit_ipcdev->base[ISPDRIVER_IPC][BASE_IFACE] = addr;
0257
0258     addr = devm_platform_ioremap_resource(pdev, 4);
0259     if (!IS_ERR(addr))
0260         punit_ipcdev->base[GTDRIVER_IPC][BASE_DATA] = addr;
0261
0262     addr = devm_platform_ioremap_resource(pdev, 5);
0263     if (!IS_ERR(addr))
0264         punit_ipcdev->base[GTDRIVER_IPC][BASE_IFACE] = addr;
0265
0266     return 0;
0267 }
0268
0269 static int intel_punit_ipc_probe(struct platform_device *pdev)
0270 {
0271     int irq, ret;
0272
0273     punit_ipcdev = devm_kzalloc(&pdev->dev,
0274                     sizeof(*punit_ipcdev), GFP_KERNEL);
0275     if (!punit_ipcdev)
0276         return -ENOMEM;
0277
0278     platform_set_drvdata(pdev, punit_ipcdev);
0279
0280     irq = platform_get_irq_optional(pdev, 0);
0281     if (irq < 0) {
0282         dev_warn(&pdev->dev, "Invalid IRQ, using polling mode\n");
0283     } else {
0284         ret = devm_request_irq(&pdev->dev, irq, intel_punit_ioc,
0285                        IRQF_NO_SUSPEND, "intel_punit_ipc",
0286                        &punit_ipcdev);
0287         if (ret) {
0288             dev_err(&pdev->dev, "Failed to request irq: %d\n", irq);
0289             return ret;
0290         }
0291         punit_ipcdev->irq = irq;
0292     }
0293
0294     ret = intel_punit_get_bars(pdev);
0295     if (ret)
0296         return ret;
0297
0298     punit_ipcdev->dev = &pdev->dev;
0299     mutex_init(&punit_ipcdev->lock);
0300     init_completion(&punit_ipcdev->cmd_complete);
0301
0302     return 0;
0303 }
0304
0305 static int intel_punit_ipc_remove(struct platform_device *pdev)
0306 {
0307     return 0;
0308 }
0309
0310 static const struct acpi_device_id punit_ipc_acpi_ids[] = {
0311     { "INT34D4", 0 },
0312     { }
0313 };
0314 MODULE_DEVICE_TABLE(acpi, punit_ipc_acpi_ids);
0315
0316 static struct platform_driver intel_punit_ipc_driver = {
0317     .probe = intel_punit_ipc_probe,
0318     .remove = intel_punit_ipc_remove,
0319     .driver = {
0320         .name = "intel_punit_ipc",
0321         .acpi_match_table = punit_ipc_acpi_ids,
0322     },
0323 };
0324
0325 static int __init intel_punit_ipc_init(void)
0326 {
0327     return platform_driver_register(&intel_punit_ipc_driver);
0328 }
0329
0330 static void __exit intel_punit_ipc_exit(void)
0331 {
0332     platform_driver_unregister(&intel_punit_ipc_driver);
0333 }
0334
0335 MODULE_AUTHOR("Zha Qipeng <qipeng.zha@intel.com>");
0336 MODULE_DESCRIPTION("Intel P-Unit IPC driver");
0337 MODULE_LICENSE("GPL v2");
0338
0339 /* Some modules are dependent on this, so init earlier */
0340 fs_initcall(intel_punit_ipc_init);
0341 module_exit(intel_punit_ipc_exit);