drivers/net/ipa/ipa_uc.c

   1 // SPDX-License-Identifier: GPL-2.0
   2
   3 /* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved.
   4  * Copyright (C) 2018-2020 Linaro Ltd.
   5  */
   6
   7 #include <linux/types.h>
   8 #include <linux/io.h>
   9 #include <linux/delay.h>
  10 #include <linux/pm_runtime.h>
  11
  12 #include "ipa.h"
  13 #include "ipa_uc.h"
  14 #include "ipa_power.h"
  15
  16 /**
  17  * DOC:  The IPA embedded microcontroller
  18  *
  19  * The IPA incorporates a microcontroller that is able to do some additional
  20  * handling/offloading of network activity.  The current code makes
  21  * essentially no use of the microcontroller, but it still requires some
  22  * initialization.  It needs to be notified in the event the AP crashes.
  23  *
  24  * The microcontroller can generate two interrupts to the AP.  One interrupt
  25  * is used to indicate that a response to a request from the AP is available.
  26  * The other is used to notify the AP of the occurrence of an event.  In
  27  * addition, the AP can interrupt the microcontroller by writing a register.
  28  *
  29  * A 128 byte block of structured memory within the IPA SRAM is used together
  30  * with these interrupts to implement the communication interface between the
  31  * AP and the IPA microcontroller.  Each side writes data to the shared area
  32  * before interrupting its peer, which will read the written data in response
  33  * to the interrupt.  Some information found in the shared area is currently
  34  * unused.  All remaining space in the shared area is reserved, and must not
  35  * be read or written by the AP.
  36  */
  37 /* Supports hardware interface version 0x2000 */
  38
  39 /* Delay to allow a the microcontroller to save state when crashing */
  40 #define IPA_SEND_DELAY          100     /* microseconds */
  41
  42 /**
  43  * struct ipa_uc_mem_area - AP/microcontroller shared memory area
  44  * @command:            command code (AP->microcontroller)
  45  * @reserved0:          reserved bytes; avoid reading or writing
  46  * @command_param:      low 32 bits of command parameter (AP->microcontroller)
  47  * @command_param_hi:   high 32 bits of command parameter (AP->microcontroller)
  48  *
  49  * @response:           response code (microcontroller->AP)
  50  * @reserved1:          reserved bytes; avoid reading or writing
  51  * @response_param:     response parameter (microcontroller->AP)
  52  *
  53  * @event:              event code (microcontroller->AP)
  54  * @reserved2:          reserved bytes; avoid reading or writing
  55  * @event_param:        event parameter (microcontroller->AP)
  56  *
  57  * @first_error_address: address of first error-source on SNOC
  58  * @hw_state:           state of hardware (including error type information)
  59  * @warning_counter:    counter of non-fatal hardware errors
  60  * @reserved3:          reserved bytes; avoid reading or writing
  61  * @interface_version:  hardware-reported interface version
  62  * @reserved4:          reserved bytes; avoid reading or writing
  63  *
  64  * A shared memory area at the base of IPA resident memory is used for
  65  * communication with the microcontroller.  The region is 128 bytes in
  66  * size, but only the first 40 bytes (structured this way) are used.
  67  */
  68 struct ipa_uc_mem_area {
  69         u8 command;             /* enum ipa_uc_command */
  70         u8 reserved0[3];
  71         __le32 command_param;
  72         __le32 command_param_hi;
  73         u8 response;            /* enum ipa_uc_response */
  74         u8 reserved1[3];
  75         __le32 response_param;
  76         u8 event;               /* enum ipa_uc_event */
  77         u8 reserved2[3];
  78
  79         __le32 event_param;
  80         __le32 first_error_address;
  81         u8 hw_state;
  82         u8 warning_counter;
  83         __le16 reserved3;
  84         __le16 interface_version;
  85         __le16 reserved4;
  86 };
  87
  88 /** enum ipa_uc_command - commands from the AP to the microcontroller */
  89 enum ipa_uc_command {
  90         IPA_UC_COMMAND_NO_OP            = 0x0,
  91         IPA_UC_COMMAND_UPDATE_FLAGS     = 0x1,
  92         IPA_UC_COMMAND_DEBUG_RUN_TEST   = 0x2,
  93         IPA_UC_COMMAND_DEBUG_GET_INFO   = 0x3,
  94         IPA_UC_COMMAND_ERR_FATAL        = 0x4,
  95         IPA_UC_COMMAND_CLK_GATE         = 0x5,
  96         IPA_UC_COMMAND_CLK_UNGATE       = 0x6,
  97         IPA_UC_COMMAND_MEMCPY           = 0x7,
  98         IPA_UC_COMMAND_RESET_PIPE       = 0x8,
  99         IPA_UC_COMMAND_REG_WRITE        = 0x9,
 100         IPA_UC_COMMAND_GSI_CH_EMPTY     = 0xa,
 101 };
 102
 103 /** enum ipa_uc_response - microcontroller response codes */
 104 enum ipa_uc_response {
 105         IPA_UC_RESPONSE_NO_OP           = 0x0,
 106         IPA_UC_RESPONSE_INIT_COMPLETED  = 0x1,
 107         IPA_UC_RESPONSE_CMD_COMPLETED   = 0x2,
 108         IPA_UC_RESPONSE_DEBUG_GET_INFO  = 0x3,
 109 };
 110
 111 /** enum ipa_uc_event - common cpu events reported by the microcontroller */
 112 enum ipa_uc_event {
 113         IPA_UC_EVENT_NO_OP              = 0x0,
 114         IPA_UC_EVENT_ERROR              = 0x1,
 115         IPA_UC_EVENT_LOG_INFO           = 0x2,
 116 };
 117
 118 static struct ipa_uc_mem_area *ipa_uc_shared(struct ipa *ipa)
 119 {
 120         const struct ipa_mem *mem = ipa_mem_find(ipa, IPA_MEM_UC_SHARED);
 121         u32 offset = ipa->mem_offset + mem->offset;
 122
 123         return ipa->mem_virt + offset;
 124 }
 125
 126 /* Microcontroller event IPA interrupt handler */
 127 static void ipa_uc_event_handler(struct ipa *ipa, enum ipa_irq_id irq_id)
 128 {
 129         struct ipa_uc_mem_area *shared = ipa_uc_shared(ipa);
 130         struct device *dev = &ipa->pdev->dev;
 131
 132         if (shared->event == IPA_UC_EVENT_ERROR)
 133                 dev_err(dev, "microcontroller error event\n");
 134         else if (shared->event != IPA_UC_EVENT_LOG_INFO)
 135                 dev_err(dev, "unsupported microcontroller event %u\n",
 136                         shared->event);
 137         /* The LOG_INFO event can be safely ignored */
 138 }
 139
 140 /* Microcontroller response IPA interrupt handler */
 141 static void ipa_uc_response_hdlr(struct ipa *ipa, enum ipa_irq_id irq_id)
 142 {
 143         struct ipa_uc_mem_area *shared = ipa_uc_shared(ipa);
 144         struct device *dev = &ipa->pdev->dev;
 145
 146         /* An INIT_COMPLETED response message is sent to the AP by the
 147          * microcontroller when it is operational.  Other than this, the AP
 148          * should only receive responses from the microcontroller when it has
 149          * sent it a request message.
 150          *
 151          * We can drop the power reference taken in ipa_uc_power() once we
 152          * know the microcontroller has finished its initialization.
 153          */
 154         switch (shared->response) {
 155         case IPA_UC_RESPONSE_INIT_COMPLETED:
 156                 if (ipa->uc_powered) {
 157                         ipa->uc_loaded = true;
 158                         ipa_power_retention(ipa, true);
 159                         pm_runtime_mark_last_busy(dev);
 160                         (void)pm_runtime_put_autosuspend(dev);
 161                         ipa->uc_powered = false;
 162                 } else {
 163                         dev_warn(dev, "unexpected init_completed response\n");
 164                 }
 165                 break;
 166         default:
 167                 dev_warn(dev, "unsupported microcontroller response %u\n",
 168                          shared->response);
 169                 break;
 170         }
 171 }
 172
 173 /* Configure the IPA microcontroller subsystem */
 174 void ipa_uc_config(struct ipa *ipa)
 175 {
 176         ipa->uc_powered = false;
 177         ipa->uc_loaded = false;
 178         ipa_interrupt_add(ipa->interrupt, IPA_IRQ_UC_0, ipa_uc_event_handler);
 179         ipa_interrupt_add(ipa->interrupt, IPA_IRQ_UC_1, ipa_uc_response_hdlr);
 180 }
 181
 182 /* Inverse of ipa_uc_config() */
 183 void ipa_uc_deconfig(struct ipa *ipa)
 184 {
 185         struct device *dev = &ipa->pdev->dev;
 186
 187         ipa_interrupt_remove(ipa->interrupt, IPA_IRQ_UC_1);
 188         ipa_interrupt_remove(ipa->interrupt, IPA_IRQ_UC_0);
 189         if (ipa->uc_loaded)
 190                 ipa_power_retention(ipa, false);
 191
 192         if (!ipa->uc_powered)
 193                 return;
 194
 195         pm_runtime_mark_last_busy(dev);
 196         (void)pm_runtime_put_autosuspend(dev);
 197 }
 198
 199 /* Take a proxy power reference for the microcontroller */
 200 void ipa_uc_power(struct ipa *ipa)
 201 {
 202         static bool already;
 203         struct device *dev;
 204         int ret;
 205
 206         if (already)
 207                 return;
 208         already = true;         /* Only do this on first boot */
 209
 210         /* This power reference dropped in ipa_uc_response_hdlr() above */
 211         dev = &ipa->pdev->dev;
 212         ret = pm_runtime_get_sync(dev);
 213         if (ret < 0) {
 214                 pm_runtime_put_noidle(dev);
 215                 dev_err(dev, "error %d getting proxy power\n", ret);
 216         } else {
 217                 ipa->uc_powered = true;
 218         }
 219 }
 220
 221 /* Send a command to the microcontroller */
 222 static void send_uc_command(struct ipa *ipa, u32 command, u32 command_param)
 223 {
 224         struct ipa_uc_mem_area *shared = ipa_uc_shared(ipa);
 225         u32 offset;
 226         u32 val;
 227
 228         /* Fill in the command data */
 229         shared->command = command;
 230         shared->command_param = cpu_to_le32(command_param);
 231         shared->command_param_hi = 0;
 232         shared->response = 0;
 233         shared->response_param = 0;
 234
 235         /* Use an interrupt to tell the microcontroller the command is ready */
 236         val = u32_encode_bits(1, UC_INTR_FMASK);
 237         offset = ipa_reg_irq_uc_offset(ipa->version);
 238         iowrite32(val, ipa->reg_virt + offset);
 239 }
 240
 241 /* Tell the microcontroller the AP is shutting down */
 242 void ipa_uc_panic_notifier(struct ipa *ipa)
 243 {
 244         if (!ipa->uc_loaded)
 245                 return;
 246
 247         send_uc_command(ipa, IPA_UC_COMMAND_ERR_FATAL, 0);
 248
 249         /* give uc enough time to save state */
 250         udelay(IPA_SEND_DELAY);
 251 }