1 // SPDX-License-Identifier: GPL-2.0 2 3 /* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved. 4 * Copyright (C) 2018-2022 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) 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) 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 void ipa_uc_interrupt_handler(struct ipa *ipa, enum ipa_irq_id irq_id) 174 { 175 /* Silently ignore anything unrecognized */ 176 if (irq_id == IPA_IRQ_UC_0) 177 ipa_uc_event_handler(ipa); 178 else if (irq_id == IPA_IRQ_UC_1) 179 ipa_uc_response_hdlr(ipa); 180 } 181 182 /* Configure the IPA microcontroller subsystem */ 183 void ipa_uc_config(struct ipa *ipa) 184 { 185 ipa->uc_powered = false; 186 ipa->uc_loaded = false; 187 ipa_interrupt_enable(ipa, IPA_IRQ_UC_0); 188 ipa_interrupt_enable(ipa, IPA_IRQ_UC_1); 189 } 190 191 /* Inverse of ipa_uc_config() */ 192 void ipa_uc_deconfig(struct ipa *ipa) 193 { 194 struct device *dev = &ipa->pdev->dev; 195 196 ipa_interrupt_disable(ipa, IPA_IRQ_UC_1); 197 ipa_interrupt_disable(ipa, IPA_IRQ_UC_0); 198 if (ipa->uc_loaded) 199 ipa_power_retention(ipa, false); 200 201 if (!ipa->uc_powered) 202 return; 203 204 pm_runtime_mark_last_busy(dev); 205 (void)pm_runtime_put_autosuspend(dev); 206 } 207 208 /* Take a proxy power reference for the microcontroller */ 209 void ipa_uc_power(struct ipa *ipa) 210 { 211 static bool already; 212 struct device *dev; 213 int ret; 214 215 if (already) 216 return; 217 already = true; /* Only do this on first boot */ 218 219 /* This power reference dropped in ipa_uc_response_hdlr() above */ 220 dev = &ipa->pdev->dev; 221 ret = pm_runtime_get_sync(dev); 222 if (ret < 0) { 223 pm_runtime_put_noidle(dev); 224 dev_err(dev, "error %d getting proxy power\n", ret); 225 } else { 226 ipa->uc_powered = true; 227 } 228 } 229 230 /* Send a command to the microcontroller */ 231 static void send_uc_command(struct ipa *ipa, u32 command, u32 command_param) 232 { 233 struct ipa_uc_mem_area *shared = ipa_uc_shared(ipa); 234 const struct reg *reg; 235 u32 val; 236 237 /* Fill in the command data */ 238 shared->command = command; 239 shared->command_param = cpu_to_le32(command_param); 240 shared->command_param_hi = 0; 241 shared->response = 0; 242 shared->response_param = 0; 243 244 /* Use an interrupt to tell the microcontroller the command is ready */ 245 reg = ipa_reg(ipa, IPA_IRQ_UC); 246 val = reg_bit(reg, UC_INTR); 247 248 iowrite32(val, ipa->reg_virt + reg_offset(reg)); 249 } 250 251 /* Tell the microcontroller the AP is shutting down */ 252 void ipa_uc_panic_notifier(struct ipa *ipa) 253 { 254 if (!ipa->uc_loaded) 255 return; 256 257 send_uc_command(ipa, IPA_UC_COMMAND_ERR_FATAL, 0); 258 259 /* give uc enough time to save state */ 260 udelay(IPA_SEND_DELAY); 261 } 262